text
stringlengths 105
4.57k
| label
int64 0
1
| label_text
stringclasses 2
values |
|---|---|---|
MacConkey agar is culture medium designed to grow Gram-negative bacteria and stain them for lactose fermentation. It contains bile salts (to inhibit most Gram-positive bacteria), crystal violet dye (which also inhibits certain Gram-positive bacteria), neutral red dye (which stains microbes fermenting lactose), lactose and peptone. Alfred Theodore MacConkey developed it while working as a bacteriologist for the Royal Commission on Sewage Disposal in the United Kingdom.
Endo agar contains peptone, lactose, dipotassium phosphate, agar, sodium sulfite, basic fuchsin and was originally developed for the isolation of Salmonella typhi, but is now commonly used in water analysis. As in MacConkey agar, coliform organisms ferment the lactose, and the colonies become red. Non-lactose-fermenting organisms produce clear, colourless colonies against the faint pink background of the medium.
mFC medium is used in membrane filtration and contains selective and differential agents. These include rosolic acid to inhibit bacterial growth in general, except for fecal coliforms, bile salts inhibit non-enteric bacteria and aniline blue indicates the ability of fecal coliforms to ferment lactose to acid that causes a pH change in the medium.
TYEA medium contains tryptone, yeast extract, common salt and L-arabinose per liter of glass distilled
water and is a non selective medium usually cultivated at two temperatures (22 and 36 °C) to determine a general level of contamination (a.k.a. colony count). | 0 | Theoretical and Fundamental Chemistry |
Mycoremediation can even be used for fire management with the encapsulation method. This process consists of using fungal spores coated with agarose in a pellet form, which is introduced to a substrate in the burnt forest, breaking down toxins and stimulating growth. | 1 | Applied and Interdisciplinary Chemistry |
21-Crown-7 is an organic compound with the formula [CHO] and the IUPAC name of 1,4,7,10,13,16,19-heptaoxacycloheneicosane. Like other crown ethers, 21-crown-7 functions as a ligand for some metal cations with a particular affinity for caesium cations. The dipole moment of 21-crown-7 varies in different solvents and under different temperatures. | 0 | Theoretical and Fundamental Chemistry |
The Angeli–Rimini reaction has recently been applied in solid-phase synthesis with the sulfonamide covalently linked to a polystyrene solid support. | 0 | Theoretical and Fundamental Chemistry |
The use of the term hydrate is still acceptable e.g. NaSO10HO, sodium sulfate decahydrate. The recommended method would be to name it sodium sulfate—water(1/10). Similarly other examples of lattice compounds are:
*CaCl8NH, calcium chloride— ammonia (1/8)
*2NaCO3HO, sodium carbonate—hydrogen peroxide (2/3)
*AlCl4EtOH, aluminium chloride—ethanol (1/4) | 0 | Theoretical and Fundamental Chemistry |
Clinical trial costs vary depending on trial phase, type of trial, and disease studied. A study of clinical trials conducted in the United States from 2004 to 2012 found the average cost of PhaseI trials to be between $1.4 million and $6.6 million, depending on the type of disease. Phase II trials ranged from $7 million to $20 million, and PhaseIII trials from $11 million to $53 million. | 1 | Applied and Interdisciplinary Chemistry |
*Shortly after his funeral, his wife organised a memorial tablet for him in Westminster Abbey at a cost of £142.
*In 1872, a statue of Davy was erected in front of the Market Building, Penzance, (now owned by Lloyds TSB) at the top of Market Jew Street, Penzance.
*A commemorative slate plaque on 4 Market Jew Street, Penzance, claims the location as his birthplace. A secondary school in Coombe Road, Penzance, is named Humphry Davy School.
*A pub at 32 Alverton Street, Penzance, is named "The Sir Humphry Davy".
*One of the science buildings of the University of Plymouth is named The Davy Building.
*There is a road named Humphry Davy Way adjacent to the docks in Bristol.
*Outside the entrance to Sunderland Football Clubs Stadium of Light stands a giant Davy Lamp, in recognition of local mining heritage and the importance of Davys safety lamp to the mining industry.
*There is a street named Humphry-Davy-Straße in the industrial quarter of the town of Cuxhaven, Schleswig-Holstein, Germany.
*A satellite of the University of Sheffield at Golden Smithies Lane in Wath upon Dearne (Manvers) was called Humphry Davy House and was home to the School of Nursing and Midwifery until April 2009.
*Davy Sound in Greenland was named in his honour by William Scoresby (1789–1857).
*There is a zone of activity commercial area in La Grand-Combe, Gard, France, a former mining town, named after Davy.
*Mount Davy in New Zealand's Paparoa Range was named after him by Julius von Haast. | 1 | Applied and Interdisciplinary Chemistry |
In earlier years it was thought that apamin was a rather nontoxic compound (LD = 15 mg/kg in mice) compared to the other compounds in bee venom. The current lethal dose values of apamin measured in mice are given below. There are no data known specific for humans.
Intraperitoneal (mouse) LD: 3.8 mg/kg
Subcutaneous (mouse) LD: 2.9 mg/kg
Intravenous (mouse) LD: 4 mg/kg
Intracerebral (mouse) LD: 1800 ng/kg
Parenteral (mouse) LD: 600 mg/kg | 1 | Applied and Interdisciplinary Chemistry |
Cytochrome c oxidase, also known as complex IV, is the final protein complex in the electron transport chain. The mammalian enzyme has an extremely complicated structure and contains 13 subunits, two heme groups, as well as multiple metal ion cofactors – in all, three atoms of copper, one of magnesium and one of zinc.
This enzyme mediates the final reaction in the electron transport chain and transfers electrons to oxygen and hydrogen (protons), while pumping protons across the membrane. The final electron acceptor oxygen is reduced to water in this step. Both the direct pumping of protons and the consumption of matrix protons in the reduction of oxygen contribute to the proton gradient. The reaction catalyzed is the oxidation of cytochrome c and the reduction of oxygen: | 1 | Applied and Interdisciplinary Chemistry |
By visual inspection, the treated region are examined. The treatment depth can be checked with a special gauge.
A digital display of the operating pressure allows the user to control the entire process. | 1 | Applied and Interdisciplinary Chemistry |
Soil tilth is naturally maintained by the interaction of plant roots with the soil biota.
Short lived tilth can be obtained through mechanical and biological manipulation. | 0 | Theoretical and Fundamental Chemistry |
Upon illumination of the chloroplasts, the pH of the stroma rises from 7.0 to 8.0 because of the proton (hydrogen ion, ) gradient created across the thylakoid membrane. The movement of protons into thylakoids is driven by light and is fundamental to ATP synthesis in chloroplasts (Further reading: Photosynthetic reaction centre; Light-dependent reactions). To balance ion potential across the membrane, magnesium ions () move out of the thylakoids in response, increasing the concentration of magnesium in the stroma of the chloroplasts. RuBisCO has a high optimal pH (can be >9.0, depending on the magnesium ion concentration) and, thus, becomes "activated" by the introduction of carbon dioxide and magnesium to the active sites as described above. | 0 | Theoretical and Fundamental Chemistry |
Pyroglutamyl-histidyl-glycine (pEHG) is an endogenous tripeptide that acts as a tissue-specific antimitotic and selectively inhibits the proliferation of colon epithelial cells. Early research indicated that pEHG had anorectic effects in mice and was possibly involved in the pathophysiology of anorexia nervosa. However, subsequent studies have found that pEHG lacks anorectic effects and does not alter food intake in mice. | 1 | Applied and Interdisciplinary Chemistry |
Probably the most widely used current applications of refrigeration are for air conditioning of private homes and public buildings, and refrigerating foodstuffs in homes, restaurants and large storage warehouses. The use of refrigerators and walk-in coolers and freezers in kitchens, factories and warehouses for storing and processing fruits and vegetables has allowed adding fresh salads to the modern diet year round, and storing fish and meats safely for long periods.
The optimum temperature range for perishable food storage is .
In commerce and manufacturing, there are many uses for refrigeration. Refrigeration is used to liquefy gases – oxygen, nitrogen, propane, and methane, for example. In compressed air purification, it is used to condense water vapor from compressed air to reduce its moisture content. In oil refineries, chemical plants, and petrochemical plants, refrigeration is used to maintain certain processes at their needed low temperatures (for example, in alkylation of butenes and butane to produce a high-octane gasoline component). Metal workers use refrigeration to temper steel and cutlery. When transporting temperature-sensitive foodstuffs and other materials by trucks, trains, airplanes and seagoing vessels, refrigeration is a necessity.
Dairy products are constantly in need of refrigeration, and it was only discovered in the past few decades that eggs needed to be refrigerated during shipment rather than waiting to be refrigerated after arrival at the grocery store. Meats, poultry and fish all must be kept in climate-controlled environments before being sold. Refrigeration also helps keep fruits and vegetables edible longer.
One of the most influential uses of refrigeration was in the development of the sushi/sashimi industry in Japan. Before the discovery of refrigeration, many sushi connoisseurs were at risk of contracting diseases. The dangers of unrefrigerated sashimi were not brought to light for decades due to the lack of research and healthcare distribution across rural Japan. Around mid-century, the Zojirushi corporation, based in Kyoto, made breakthroughs in refrigerator designs, making refrigerators cheaper and more accessible for restaurant proprietors and the general public. | 0 | Theoretical and Fundamental Chemistry |
"Upper bainite" forms around 400–550 °C in sheaves. These sheaves contain several laths of ferrite that are approximately parallel to each other and which exhibit a Kurdjumov-Sachs relationship with the surrounding austenite, though this relationship degrades as the transformation temperature is lowered. The ferrite in these sheaves has a carbon concentration below 0.03%, resulting in carbon-rich austenite around the laths.
The amount of cementite that forms between the laths is based on the carbon content of the steel. For a low carbon steel, typically discontinuous "stringers" or small particles of cementite will be present between laths. For steel with a higher carbon content, the stringers become continuous along the length of the adjacent laths. | 1 | Applied and Interdisciplinary Chemistry |
The term Schiff base is normally applied to these compounds when they are being used as ligands to form coordination complexes with metal ions. One example is Jacobsen's catalyst. The imine nitrogen is basic and exhibits pi-acceptor properties. Several, especially the diiminopyridines are noninnocent ligands. Many Schiff base ligands are derived from alkyl diamines and aromatic aldehydes.
Chiral Schiff bases were one of the first ligands used for asymmetric catalysis. In 1968 Ryōji Noyori developed a copper-Schiff base complex for the metal-carbenoid cyclopropanation of styrene. Schiff bases have also been incorporated into metal–organic frameworks (MOF). | 0 | Theoretical and Fundamental Chemistry |
For the simulation of wave motion near coasts and harbours, numerical models – both commercial and academic – employing Boussinesq-type equations exist. Some commercial examples are the Boussinesq-type wave modules in MIKE 21 and SMS. Some of the free Boussinesq models are Celeris, COULWAVE, and FUNWAVE. Most numerical models employ finite-difference, finite-volume or finite element techniques for the discretization of the model equations. Scientific reviews and intercomparisons of several Boussinesq-type equations, their numerical approximation and performance are e.g. , and . | 1 | Applied and Interdisciplinary Chemistry |
* Jim Wittke's class notes at Northern Arizona University
* John Fournelle's class notes at the University of Wisconsin–Madison
* John Donovan's class notes at the University of Oregon | 0 | Theoretical and Fundamental Chemistry |
At 16 billion Scoville units, resiniferatoxin is rather toxic and can inflict chemical burns in minute quantities. The primary action of resiniferatoxin is to activate sensory neurons responsible for the perception of pain. It is currently the most potent TRPV1 agonist known, with ~500x higher binding affinity for TRPV1 than capsaicin, the active ingredient in hot chili peppers such as those produced by Capsicum annuum. For rats, LD50 through oral ingestion is 148.1 mg/kg. It causes severe burning pain in sub-microgram (less than 1/1,000,000th of a gram) quantities when ingested orally. | 0 | Theoretical and Fundamental Chemistry |
Piobert's law applies to the reaction of solid propellant grains to generate hot gas. It is stated: "Burning takes place by parallel layers where the surface of the grain regresses, layer by layer, normal to the surface at every point." | 0 | Theoretical and Fundamental Chemistry |
Cyclic peroxides can be obtained by cycloaddition of singlet oxygen (generated by UV radiation) to dienes. An important example is rubrene. Six-membered cyclic peroxides are called endo peroxides. The four-membered dioxetanes can be obtained by 2+2 cycloaddition of oxygen to alkenes.
The hazards associated with storage of ethers in air is attributed to the formation of hydroperoxides via the direct albeit slow reaction of triplet oxygen with C-H bonds. | 0 | Theoretical and Fundamental Chemistry |
Simplified sanitary sewers consist of small-diameter pipes, typically around , often laid at fairly flat gradients (1 in 200). Although the investment cost for simplified sanitary sewers can be about half the cost of conventional sewers, the requirements for operation and maintenance are usually higher. Simplified sewers are most common in Brazil and are also used in a number of other developing countries. | 1 | Applied and Interdisciplinary Chemistry |
As the French Revolution gained momentum, attacks mounted on the deeply unpopular Ferme générale, and it was eventually abolished in March 1791. In 1792 Lavoisier was forced to resign from his post on the Gunpowder Commission and to move from his house and laboratory at the Royal Arsenal. On 8 August 1793, all the learned societies, including the Academy of Sciences, were suppressed at the request of Abbé Grégoire.
On 24 November 1793, the arrest of all the former tax farmers was ordered. Lavoisier and the other Farmers General faced nine accusations of defrauding the state of money owed to it, and of adding water to tobacco before selling it. Lavoisier drafted their defense, refuting the financial accusations, reminding the court of how they had maintained a consistently high quality of tobacco. The court, however, was inclined to believe that by condemning them and seizing the goods of the Farmers General, it would recover huge sums for the state. Lavoisier was convicted and guillotined on 8 May 1794 in Paris, at the age of 50, along with his 27 co-defendants.
According to popular legend, the appeal to spare his life, in order that he could continue his experiments, was cut short by the judge, Coffinhal: "La République na pas besoin de savants ni de chimistes; le cours de la justice ne peut être suspendu."' ("The Republic needs neither scholars nor chemists; the course of justice cannot be delayed.") The judge Coffinhal himself would be executed less than three months later, in the wake of the Thermidorian reaction.
Lavoisiers importance to science was expressed by Lagrange who lamented the beheading by saying: "Il ne leur a fallu quun moment pour faire tomber cette tête, et cent années peut-être ne suffiront pas pour en reproduire une semblable." ("It took them only an instant to cut off this head, and one hundred years might not suffice to reproduce its like.") | 1 | Applied and Interdisciplinary Chemistry |
C5a interact with receptor protein C5a Receptor 1 (C5aR1) on the surface of target cells such as macrophages, neutrophils and endothelial cells. C5aR1 is a member of the G-protein-coupled receptor superfamily of proteins, predicted to have seven transmembrane helical domains of largely hydrophobic amino acid residues, forming three intra- and three extra-cellular loops, with an extracellular N-terminus and an intracellular C-terminus.
C5a binding to the receptor is a two-stage process: an interaction between basic residues in the helical core of C5a and acidic residues in the extracellular N-terminal domain allows the C-terminus of C5a to bind to residues in the receptor transmembrane domains. The latter interaction leads to receptor activation, and the transduction of the ligand binding signal across the cell plasma membrane to the cytoplasmic G protein G type GNAI2.
Sensitivity of C5aR1 to C5a stimulation is enhanced by lipopolysaccharides exposure. C5a, acting via C5aR1, is shown to differentially modulate lipopolysaccharides-induced inflammatory responses in primary human monocytes versus macrophages, yet this is not due to C5aR1 upregulation. C5L2 is another C5a receptor that is thought to regulate the C5a-C5aR1 effects. There is apparently contradictory evidence showing decoy receptor activity conferring anti-inflammatory properties and also signalling activity conferring pro-inflammatory properties. | 1 | Applied and Interdisciplinary Chemistry |
In this way, it has been possible to create a virtual cellular population of cardiomyocytes and vary their conductances that are related to the main ionic currents which contribute to the action potential morphology, reflective of a specific anatomical region of the heart.
In order to create a stable population of cellular action potentials, the biomarkers have to be considered. During the years, several biomarkers have been developed to best characterize the instability of cellular action potentials. Few biomarkers are reported:
*APD90: it represents the action potential duration when the phase of the repolarization is at 90%, so it is possible to associate to this value a time and it can be expressed as:
*APD90: it represents the action potential duration when the phase of the repolarization is at 50%, so it is possible to associate to this value a time and it can be expressed as:
*APD20: it represents the action potential duration when the phase of the repolarization is at 20%, so it is possible to associate to this value a time and it can be expressed as:
*Triangulation: it is a measure of how triangular is an action potential, expressed as:
*APA: it represents the action potential amplitude, expressed as:
Many other can be used according to the needs of the research . | 1 | Applied and Interdisciplinary Chemistry |
Grote–Hynes theory is a theory of reaction rate in a solution phase. This rate theory was developed by James T. Hynes with his graduate student Richard F. Grote in 1980.
The theory is based on the generalized Langevin equation (GLE). This theory introduced the concept of frequency dependent friction for chemical rate processes in solution phase. Because of inclusion of the frequency dependent friction instead of constant friction, the theory successfully predicts the rate constant including where the reaction barrier is large and of high frequency, where the diffusion over the barrier starts decoupling from viscosity of the medium. This was the weakness of Kramer's rate theory, which underestimated the reaction rate having large barrier with high frequency. | 0 | Theoretical and Fundamental Chemistry |
Optical biotransducers, used in optical biosensors for signal transduction, use photons in order to collect information about analyte. These are highly sensitive, highly specific, small in size and cost effective.
The detection mechanism of optical biotransducer depends upon the enzyme system that converts analyte into products which are either oxidized or reduced at the working electrode.
Evanescent field detection principle is most commonly used in an optical biosensor system as the transduction principle . This principle is one of the most sensitive detection methods. It enables the detection of fluorophores exclusively in the close proximity of the optical fiber. | 1 | Applied and Interdisciplinary Chemistry |
When a substituent group is located ortho position to the carboxyl group in a substituted benzoic acid compound, the compound becomes more acidic surpassing the unmodified benzoic acid.
Generally ortho-substituted benzoic acids are stronger acids than their meta and para isomers. | 0 | Theoretical and Fundamental Chemistry |
When electrodes are placed in an electrolyte and a voltage is applied, the electrolyte will conduct electricity. Lone electrons normally cannot pass through the electrolyte; instead, a chemical reaction occurs at the cathode, providing electrons to the electrolyte. Another reaction occurs at the anode, consuming electrons from the electrolyte. As a result, a negative charge cloud develops in the electrolyte around the cathode, and a positive charge develops around the anode. The ions in the electrolyte neutralize these charges, enabling the electrons to keep flowing and the reactions to continue.
For example, in a solution of ordinary table salt (sodium chloride, NaCl) in water, the cathode reaction will be
:2 HO + 2e → 2 OH + H
and hydrogen gas will bubble up; the anode reaction is
:2 NaCl → 2 Na + Cl + 2e
and chlorine gas will be liberated into solution where it reacts with the sodium and hydroxyl ions to produce sodium hypochlorite - household bleach. The positively charged sodium ions Na will react toward the cathode, neutralizing the negative charge of OH there, and the negatively charged hydroxide ions OH will react toward the anode, neutralizing the positive charge of Na there. Without the ions from the electrolyte, the charges around the electrode would slow down continued electron flow; diffusion of H and OH through water to the other electrode takes longer than movement of the much more prevalent salt ions.
Electrolytes dissociate in water because water molecules are dipoles and the dipoles orient in an energetically favorable manner to solvate the ions.
In other systems, the electrode reactions can involve the metals of the electrodes as well as the ions of the electrolyte.
Electrolytic conductors are used in electronic devices where the chemical reaction at a metal-electrolyte interface yields useful effects.
* In batteries, two materials with different electron affinities are used as electrodes; electrons flow from one electrode to the other outside of the battery, while inside the battery the circuit is closed by the electrolyte's ions. Here, the electrode reactions convert chemical energy to electrical energy.
* In some fuel cells, a solid electrolyte or proton conductor connects the plates electrically while keeping the hydrogen and oxygen fuel gases separated.
* In electroplating tanks, the electrolyte simultaneously deposits metal onto the object to be plated, and electrically connects that object in the circuit.
* In operation-hours gauges, two thin columns of mercury are separated by a small electrolyte-filled gap, and, as charge is passed through the device, the metal dissolves on one side and plates out on the other, causing the visible gap to slowly move along.
* In electrolytic capacitors the chemical effect is used to produce an extremely thin dielectric or insulating coating, while the electrolyte layer behaves as one capacitor plate.
* In some hygrometers the humidity of air is sensed by measuring the conductivity of a nearly dry electrolyte.
* Hot, softened glass is an electrolytic conductor, and some glass manufacturers keep the glass molten by passing a large current through it. | 0 | Theoretical and Fundamental Chemistry |
TRIM33 acts as a tumor suppressor gene preventing the development chronic myelomonocytic leukemia.
TRIM33 regulates also the TRIM28 receptor and promotes physiological aging of hematopoietic stem cells.
TRIM33 acts as an oncogene by preventing apoptosis in B-cell leukemias. | 1 | Applied and Interdisciplinary Chemistry |
The minimum angle, , which an oblique shock can have is the Mach angle , where is the initial Mach number before the shock and the greatest angle corresponds to a normal shock. The range of shock angles is therefore . To calculate the pressures for this range of angles, the Rankine–Hugoniot equations are solved for pressure:
To calculate the possible flow deflection angles, the relationship between shock angle and is used:
Where is the ratio of specific heats and is the flow deflection angle. | 1 | Applied and Interdisciplinary Chemistry |
Aerobic exercise provokes a systemic cytokine response, including, for example, IL-6, IL-1 receptor antagonist (IL-1ra), and IL-10 (Interleukin 10) and the concentrations of chemokines, IL-8, macrophage inflammatory protein α (MIP-1α), MIP-1β, and MCP-1 rise after vigorous exercise. IL-6 was identified as a myokine based on the observation that it increased in an exponential fashion proportional to the length of exercise and the amount of muscle mass engaged in the exercise. This increase is followed by the appearance of IL-1ra and the anti-inflammatory cytokine IL-10. In general, the cytokine response to exercise and sepsis differs with regard to TNF-α. Thus, the cytokine response to exercise is not preceded by an increase in plasma-TNF-α. Following exercise, the basal plasma IL-6 concentration may increase up to 100-fold, but less dramatic increases are more frequent. The exercise-induced increase of plasma IL-6 occurs in an exponential manner and the peak IL-6 level is reached at the end of the exercise or shortly thereafter. It is the combination of mode, intensity, and duration of the exercise that determines the magnitude of the exercise-induced increase of plasma IL-6.
As studies have demonstrated IL-6 has pro-inflammatory functions when evaluated in regard to sepsis and obesity, it was initially hypothesized that the exercise-induced IL-6 response was related to muscle damage. However, a recent study suggests that eccentric exercise is not associated with a larger increase in plasma IL-6 than exercise involving concentric “nondamaging” muscle contractions. This finding supports the hypothesis that muscle damage is not required to provoke an increase in plasma IL-6 during exercise.
IL-6, among an increasing number of other recently identified myokines, remains an important topic of myokine research. It appears in muscle tissue and in the circulation during exercise at levels up to one hundred times basal rates, as noted, and may have a beneficial impact on health and bodily functioning with transient increases as P. Munoz-Canoves et al. write: "It appears consistently in the literature that IL-6, produced locally by different cell types, has a positive impact on the proliferative capacity of muscle stem cells. This physiological mechanism functions to provide enough muscle progenitors in situations that require a high number of these cells, such as during the processes of muscle regeneration and hypertrophic growth after an acute stimulus. IL-6 is also the founding member of the myokine family of muscle-produced cytokines. Indeed, muscle-produced IL-6 after repeated contractions also has important autocrine and paracrine benefits, acting as a myokine, in regulating energy metabolism, controlling, for example, metabolic functions and stimulating glucose production. It is important to note that these positive effects of IL-6 and other myokines are normally associated with its transient production and short-term action." | 1 | Applied and Interdisciplinary Chemistry |
According to R. Balasubramaniam and A. V. Ramesh Kumar (2003), the pillar shows "excellent" atmospheric corrosion resistance.
Ray et al. (1997) analyzed portions of the two smaller fragments. Their analysis revealed the following chemical composition (weight %):
Balasubramaniam (2002) also obtained a small portion of the pillar with ASI's permission, and used an electron probe microanalyzer to analyze its chemical composition. He found that "the composition varied from one location to another":
The typical composition of the slag was 55.8% iron, 27.8% silicon, 16.3% phosphorus, and 0.1% manganese. | 1 | Applied and Interdisciplinary Chemistry |
The probability of a transition taking place is the most important factor influencing the intensity of an observed rotational line. This probability is proportional to the population of the initial state involved in the transition. The population of a rotational state depends on two factors. The number of molecules in an excited state with quantum number J, relative to the number of molecules in the ground state, N/N is given by the Boltzmann distribution as
where k is the Boltzmann constant and T the absolute temperature. This factor decreases as J increases. The second factor is the degeneracy of the rotational state, which is equal to . This factor increases as J increases. Combining the two factors
The maximum relative intensity occurs at
The diagram at the right shows an intensity pattern roughly corresponding to the spectrum above it. | 0 | Theoretical and Fundamental Chemistry |
EQCM is broadly used to study the deposition/dissolution process on electrode surface, such as the oscillation of electrode potential during Cu/CuO layered nanostructure electrodeposition, deposition growth process of cobalt and nickel hexacyanoferrate in calcium nitrate and barium nitrate electrolyte solution, and the Mg electrode electrochemical behaviour in various polar aprotic electrolyte solutions. EQCM can be used as a powerful tool for corrosion and corrosion protection study, which is usually combined with other characterization technologies. A previous work used EQCM and XPS studied Fe-17Cr-33Mo/ Fe-25Cr alloy electrodes mass changes during the potential sweep and potential step experiments in the passive potential region in an acidic and a basic electrolyte. Another previous work used EQCM and SEM to study the influence of purine (PU) on Cu electrode corrosion and spontaneous dissolution in NaCl electrolyte solution. | 0 | Theoretical and Fundamental Chemistry |
TEOS-10 (Thermodynamic Equation of Seawater - 2010) is the international standard for the use and calculation of the thermodynamic properties of seawater, humid air and ice. It supersedes the former standard EOS-80 (Equation of State of Seawater 1980). TEOS-10 is used by oceanographers and climate scientists to calculate and model properties of the oceans such as heat content in an internationally comparable way. | 0 | Theoretical and Fundamental Chemistry |
The general form quoted for a mass balance is The mass that enters a system must, by conservation of mass, either leave the system or accumulate within the system.
Mathematically the mass balance for a system without a chemical reaction is as follows:
Strictly speaking the above equation holds also for systems with chemical reactions if the terms in the balance equation are taken to refer to total mass, i.e. the sum of all the chemical species of the system. In the absence of a chemical reaction the amount of any chemical species flowing in and out will be the same; this gives rise to an equation for each species present in the system. However, if this is not the case then the mass balance equation must be amended to allow for the generation or depletion (consumption) of each chemical species. Some use one term in this equation to account for chemical reactions, which will be negative for depletion and positive for generation. However, the conventional form of this equation is written to account for both a positive generation term (i.e. product of reaction) and a negative consumption term (the reactants used to produce the products). Although overall one term will account for the total balance on the system, if this balance equation is to be applied to an individual species and then the entire process, both terms are necessary. This modified equation can be used not only for reactive systems, but for population balances such as arise in particle mechanics problems. The equation is given below; note that it simplifies to the earlier equation in the case that the generation term is zero.
*In the absence of a nuclear reaction the number of atoms flowing in and out must remain the same, even in the presence of a chemical reaction.
*For a balance to be formed, the boundaries of the system must be clearly defined.
*Mass balances can be taken over physical systems at multiple scales.
*Mass balances can be simplified with the assumption of steady state, in which the accumulation term is zero. | 1 | Applied and Interdisciplinary Chemistry |
The specific biochemical mechanism of lithium action in stabilizing mood is unknown.
Upon ingestion, lithium becomes widely distributed in the central nervous system and interacts with a number of neurotransmitters and receptors, decreasing norepinephrine release and increasing serotonin synthesis.
Unlike many other psychoactive drugs, typically produces no obvious psychotropic effects (such as euphoria) in normal individuals at therapeutic concentrations.
Lithium may also increase the release of serotonin by neurons in the brain. In vitro studies performed on serotonergic neurons from rat raphe nuclei have shown that when these neurons are treated with lithium, serotonin release is enhanced during a depolarization compared to no lithium treatment and the same depolarization.
Lithium both directly and indirectly inhibits GSK3β (glycogen synthase kinase 3β) which results in the activation of mTOR. This leads to an increase in neuroprotective mechanisms by facilitating the Akt signaling pathway. GSK-3β is a downstream target of monoamine systems. As such, it is directly implicated in cognition and mood regulation. During mania, GSK-3β is activated via dopamine overactivity. GSK-3β inhibits the transcription factors β-catenin and cyclic AMP (cAMP) response element binding protein (CREB), by phosphorylation. This results in a decrease in the transcription of important genes encoding for neurotrophins. In addition, several authors proposed that pAp-phosphatase could be one of the therapeutic targets of lithium. This hypothesis was supported by the low Ki of lithium for human pAp-phosphatase compatible within the range of therapeutic concentrations of lithium in the plasma of people (0.8–1 mM). The Ki of human pAp-phosphatase is ten times lower than that of GSK3β (glycogen synthase kinase 3β). Inhibition of pAp-phosphatase by lithium leads to increased levels of pAp (3′-5′ phosphoadenosine phosphate), which was shown to inhibit PARP-1.
Another mechanism proposed in 2007 is that lithium may interact with nitric oxide (NO) signalling pathway in the central nervous system, which plays a crucial role in neural plasticity. The NO system could be involved in the antidepressant effect of lithium in the Porsolt forced swimming test in mice. It was also reported that NMDA receptor blockage augments antidepressant-like effects of lithium in the mouse forced swimming test, indicating the possible involvement of NMDA receptor/NO signaling in the action of lithium in this animal model of learned helplessness.
Lithium possesses neuroprotective properties by preventing apoptosis and increasing cell longevity.
Although the search for a novel lithium-specific receptor is ongoing, the high concentration of lithium compounds required to elicit a significant pharmacological effect leads mainstream researchers to believe that the existence of such a receptor is unlikely. | 1 | Applied and Interdisciplinary Chemistry |
Gestonorone caproate is used in the palliative treatment of benign prostatic hypertrophy and endometrial cancer. It is used at a dose of 100 to 200 mg once a week by intramuscular injection. | 0 | Theoretical and Fundamental Chemistry |
Increasing the pressure in a gaseous reaction will increase the number of collisions between reactants, increasing the rate of reaction. This is because the activity of a gas is directly proportional to the partial pressure of the gas. This is similar to the effect of increasing the concentration of a solution.
In addition to this straightforward mass-action effect, the rate coefficients themselves can change due to pressure. The rate coefficients and products of many high-temperature gas-phase reactions change if an inert gas is added to the mixture; variations on this effect are called fall-off and chemical activation. These phenomena are due to exothermic or endothermic reactions occurring faster than heat transfer, causing the reacting molecules to have non-thermal energy distributions (non-Boltzmann distribution). Increasing the pressure increases the heat transfer rate between the reacting molecules and the rest of the system, reducing this effect.
Condensed-phase rate coefficients can also be affected by pressure, although rather high pressures are required for a measurable effect because ions and molecules are not very compressible. This effect is often studied using diamond anvils.
A reaction's kinetics can also be studied with a pressure jump approach. This involves making fast changes in pressure and observing the relaxation time of the return to equilibrium. | 0 | Theoretical and Fundamental Chemistry |
Glutamate-1-semialdehyde is a molecule formed from by the reduction of tRNA bound glutamate, catalyzed by glutamyl-tRNA reductase. It is isomerized by glutamate-1-semialdehyde 2,1-aminomutase to give aminolevulinic acid in the biosynthesis of porphyrins, including heme and chlorophyll. | 1 | Applied and Interdisciplinary Chemistry |
A purge box is typically used so that absorption of THz radiation by gaseous water molecules is minimized. A dry air source is often used for this purpose, however, a nitrogen gas source may also be used.
Water is known to have many discrete absorptions in the THz region that are rotational modes of water molecules. Alternatively, nitrogen, as a diatomic molecule, has no electric dipole moment, and does not (for the purposes of typical THz-TDS) absorb THz radiation. Thus, a purge box may be filled with nitrogen gas so no unintended discrete absorptions in the THz frequency range occur. | 0 | Theoretical and Fundamental Chemistry |
The SI unit for Collective dose, S, is man-sieverts. The person-rem is sometimes used as the non SI unit in some regulatory systems. | 0 | Theoretical and Fundamental Chemistry |
In the Couette flow, instead of the translational motion of one of the plate, an oscillation of one plane will be executed. If we have a bottom wall at rest at and the upper wall at is executing an oscillatory motion with velocity , then the velocity field is given by
The frictional force per unit area on the moving plane is and on the fixed plane is . | 1 | Applied and Interdisciplinary Chemistry |
When the primary beam consists of accelerated electrons, the probe is termed an electron microprobe, when the primary beam consists of accelerated ions, the term ion microprobe is used. The term microprobe may also be applied to optical analytical techniques, when the instrument is set up to analyse micro samples or micro areas of larger specimens. Such techniques include micro Raman spectroscopy, micro infrared spectroscopy and micro LIBS. All of these techniques involve modified optical microscopes to locate the area to be analysed, direct the probe beam and collect the analytical signal.
A laser microprobe is a mass spectrometer that uses ionization by a pulsed laser and subsequent mass analysis of the generated ions. | 0 | Theoretical and Fundamental Chemistry |
In these cycles and engines the working fluid is always a gas (i.e., there is no phase change):
*Carnot cycle (Carnot heat engine)
*Ericsson cycle (Caloric Ship John Ericsson)
*Stirling cycle (Stirling engine, thermoacoustic devices)
*Internal combustion engine (ICE):
**Otto cycle (e.g. gasoline/petrol engine)
**Diesel cycle (e.g. Diesel engine)
**Atkinson cycle (Atkinson engine)
**Brayton cycle or Joule cycle originally Ericsson cycle (gas turbine)
**Lenoir cycle (e.g., pulse jet engine)
**Miller cycle (Miller engine) | 0 | Theoretical and Fundamental Chemistry |
Further classification of the jet can be related to how the nearfield zone develops due to the compressible effects that govern it. When the jet first exists the orifice or nozzle, it will expand very quickly, resulting in an over-expansion of the flow (which will also reduce the temperature and density of the flow as quickly as it depressurized). Gases that have expanded to a pressure lower than the one of the surrounding fluid will be compressed inwards, causing an increase in the pressure of the flow. If this re-compression leads to the fluid having a higher pressure than the surrounding fluid, another expansion will happen.
This process will repeat until the pressure difference between ambient pressure and jet pressure is null (or close to null).
Compression and expansion are accomplished through a series of shock waves, formed as a result of Prandlt-Meyer expansion and compression waves.
Development of the aforementioned shock waves will be related to the difference in pressure between the stagnant conditions or downstream conditions and the ambient conditions (η = P/P and η = P/P, respectively), as well as the mach number (Ma = V/V, where V is the velocity of the flow and V is the speed of sound of the medium). With varying pressure ratios, under-expanded jets can be classified as:
*Moderately under-expanded jet: Nearfield with diamond shaped structures (each structure is called a cell). A Prandlt-Meyer expansion generates oblique expansion waves that expand the fluid downstream from the exit orifice. As these waves attain constant pressure from the surrounding fluid, they are deflected back as compression waves, converging in oblique shock waves (called intercepting shock). When they meet on the axis of the jet, reflected shock waves move outwardly until they attain constant pressure from the surrounding fluid, repeating the process, and in turn, recreating the cell structure (this phenomenon occurs in air at a range of 2 ≤ η ≤ 4 or 1.1 ≤ η ≤ 3).
*Highly under-expanded jet: Nearfield with barrel shaped structures. As the pressure ratio increases, the intercepting shock waves cant meet on the axis of the jet anymore, which forces the generation of a normal shock wave when the intercepting shock waves go beyond a certain critical angle (The normal shock wave is called Mach Disk). From the interception point of the mach disk and the intercepting shock', a residual slipstream will reflect outwardly, until it reaches constant pressure from the surrounding fluid, repeating the process, recreating the barrel shaped cell structure (this phenomenon occurs in air at a range of 5 ≤ η ≤ 7 or 2 ≤ η ≤ 4 ).
*Extremely under-expanded jet: Nearfield with a single cell structure. When the pressure ratio goes beyond a critical value (in air at a range of η ≥ 7 or η ≥ 4 ), cell numbers within the nearfield of the jet decrease, until they all coalesce into a single cell with a single mach disk. Due to the increase in velocity and lower pressure zones around the jet, ambient fluid entrainment will increase. | 1 | Applied and Interdisciplinary Chemistry |
In chemical separation terminology, the raffinate (from French raffiner, to refine) is a product which has had a component or components removed. The product having the removed materials is referred to as the extract. For example, in solvent extraction, the raffinate is the liquid stream which remains after solutes from the original liquid are removed through contact with an immiscible liquid. In metallurgy, raffinating refers to a process in which impurities are removed from liquid material.
In pressure swing adsorption the raffinate refers to the gas which is not adsorbed during the high pressure stage. The species which is desorbed from the adsorbent at low pressure may be called the "extract" product. | 0 | Theoretical and Fundamental Chemistry |
Hexaamminecobalt(III) chloride is the chemical compound with the formula [Co(NH)]Cl. It is the chloride salt of the coordination complex [Co(NH)], which is considered an archetypal "Werner complex", named after the pioneer of coordination chemistry, Alfred Werner. The cation itself is a metal ammine complex with six ammonia ligands attached to the cobalt(III) ion. | 0 | Theoretical and Fundamental Chemistry |
The stability of the Mg-Mg bond needed to be dealt with. Researchers began to investigate sterically demanding guanidinates and amidinates. Their stabilizing abilities in low-oxidation state chemistry was attractive since it allowed for other low-valent main group complexes to be achieved. This research also allowed for the first stable dimer Mg(I) dimer, [{(Priso)Mg}]. Potassium reduction of heteroleptic Mg(II) iodide precursor complexes were then carried out. The ligands guanidinato and, β-diketiminato Mg(II) iodide etherate complexes can be prepared from free NH ligands and methyl magnesium iodide in diethyl ether. An example of the synthesis of the precursor synthesis can be shown below. An additional precursor synthesis is shown, needed for [{(Nacnac)Mg}], which can be explained in the section below. | 0 | Theoretical and Fundamental Chemistry |
Plasmonic nanoparticles have demonstrated a wide potential for the establishment of innovative cancer treatments. Despite that, there are still not plasmonic nanomaterials employed in the clinical practice, because the associated metal persistence. Preliminary research indicates that some nanomaterials, among which gold nanorods and ultrasmall-in-nano architectures, can convert IR laser light into localized heat, also in combination with other established cancer treatments. | 0 | Theoretical and Fundamental Chemistry |
He died on January 4, 1882, at his home in Hastings-on-Hudson, New York, at the age of 70. The funeral was held at St Mark's Church in-the-Bowery in New York City. He was buried in Green-Wood Cemetery, Brooklyn, New York. | 0 | Theoretical and Fundamental Chemistry |
The versatility of the Sonogashira reaction makes it a widely used reaction in the synthesis of a variety of compounds. One such pharmaceutical application is in the synthesis of SIB-1508Y, which is more commonly known as Altinicline. Altinicline is a nicotinic acetylcholine receptor agonist that has shown potential in the treatment of Parkinsons disease, Alzheimers disease, Tourette's syndrome, schizophrenia, and attention deficit hyperactivity disorder (ADHD). As of 2008, Altinicline has undergone Phase II clinical trials.
The Sonogashira cross coupling reaction can be used in the synthesis of imidazopyridine derivatives. | 0 | Theoretical and Fundamental Chemistry |
As the roughness extends into turbulent core, the Fanning friction factor becomes independent of fluid viscosity at large Reynolds numbers, as illustrated by Nikuradse and Reichert (1943) for the flow in region of . The equation below has been modified from the original format which was developed for Darcy friction factor by a factor of | 1 | Applied and Interdisciplinary Chemistry |
Amphipathic Lipid Packing Sensor (ALPS) motifs were first identified in 2005 in ARFGAP1 and have been reviewed.
The curving of a phospholipid bilayer, for example into a liposome, causes disturbances to the packing of the lipids on the side of the bilayer that has the larger surface area (the outside of a liposome for example). The less "ordered" or "looser" packing of the lipids is recognized by ALPS motifs.
ALPS motifs are 20 to 40 amino acid long portions of proteins that have important collections of types of amino acid residues. Bulky hydrophobic amino acid residues, such as Phenylalanine, Leucine, and Tryptophan are present every 3 or 4 positions, with many polar but uncharged amino acid residues such as Glycine, Serine and Threonine between. The ALPS is unstructured in solution but folds as an alpha helix when associated with the membrane bilayer, such that the hydrophobic residues insert between loosely packed lipids and the polar residues point toward the aqueous cytoplasm. | 1 | Applied and Interdisciplinary Chemistry |
Cross-reactive carbohydrate determinants (CCDs) play a role in the context of allergy diagnosis. The terms CCD or CCDs describe protein-linked carbohydrate structures responsible for the phenomenon of cross-reactivity of sera from allergic patients towards a wide range of allergens from plants and insects. In serum-based allergy diagnosis, antibodies of the IgE class directed against CCDs therefore give the impression of polysensitization. Anti-CCD IgE, however, does not seem to elicit clinical symptoms. Diagnostic results caused by CCDs are therefore regarded as false positives. | 0 | Theoretical and Fundamental Chemistry |
There are seven different kinds of lattice systems, and each kind of lattice system has four different kinds of centerings (primitive, base-centered, body-centered, face-centered). However, not all of the combinations are unique; some of the combinations are equivalent while other combinations are not possible due to symmetry reasons. This reduces the number of unique lattices to the 14 Bravais lattices.
The distribution of the 14 Bravais lattices into 7 lattice systems is given in the following table.
In geometry and crystallography, a Bravais lattice is a category of translative symmetry groups (also known as lattices) in three directions.
Such symmetry groups consist of translations by vectors of the form
:R = na + na + na,
where n, n, and n are integers and a, a, and a are three non-coplanar vectors, called primitive vectors.
These lattices are classified by the space group of the lattice itself, viewed as a collection of points; there are 14 Bravais lattices in three dimensions; each belongs to one lattice system only. They represent the maximum symmetry a structure with the given translational symmetry can have.
All crystalline materials (not including quasicrystals) must, by definition, fit into one of these arrangements.
For convenience a Bravais lattice is depicted by a unit cell which is a factor 1, 2, 3, or 4 larger than the primitive cell. Depending on the symmetry of a crystal or other pattern, the fundamental domain is again smaller, up to a factor 48.
The Bravais lattices were studied by Moritz Ludwig Frankenheim in 1842, who found that there were 15 Bravais lattices. This was corrected to 14 by A. Bravais in 1848. | 0 | Theoretical and Fundamental Chemistry |
AFPs are thought to inhibit ice growth by an adsorption–inhibition mechanism. They adsorb to nonbasal planes of ice, inhibiting thermodynamically-favored ice growth. The presence of a flat, rigid surface in some AFPs seems to facilitate its interaction with ice via Van der Waals force surface complementarity. | 1 | Applied and Interdisciplinary Chemistry |
The vacuum ultraviolet (V‑UV) band (100–200 nm) can be generated by non-linear 4 wave mixing in gases by sum or difference frequency mixing of 2 or more longer wavelength lasers. The generation is generally done in gasses (e.g. krypton, hydrogen which are two-photon resonant near 193 nm) or metal vapors (e.g. magnesium). By making one of the lasers tunable, the V‑UV can be tuned. If one of the lasers is resonant with a transition in the gas or vapor then the V‑UV production is intensified. However, resonances also generate wavelength dispersion, and thus the phase matching can limit the tunable range of the 4 wave mixing. Difference frequency mixing (i.e., ) has an advantage over sum frequency mixing because the phase matching can provide greater tuning.
In particular, difference frequency mixing two photons of an (193 nm) excimer laser with a tunable visible or near IR laser in hydrogen or krypton provides resonantly enhanced tunable V‑UV covering from 100 nm to 200 nm. Practically, the lack of suitable gas / vapor cell window materials above the lithium fluoride cut-off wavelength limit the tuning range to longer than about 110 nm. Tunable V‑UV wavelengths down to 75 nm was achieved using window-free configurations. | 0 | Theoretical and Fundamental Chemistry |
Heme B or haem B (also known as protoheme IX) is the most abundant heme. Hemoglobin and myoglobin are examples of oxygen transport proteins that contain heme B. The peroxidase family of enzymes also contain heme B. The COX-1 and COX-2 enzymes (cyclooxygenase) of recent fame, also contain heme B at one of two active sites.
Generally, heme B is attached to the surrounding protein matrix (known as the apoprotein) through a single coordination bond between the heme iron and an amino-acid side-chain.
Both hemoglobin and myoglobin have a coordination bond to an evolutionarily-conserved histidine, while nitric oxide synthase and cytochrome P450 have a coordination bond to an evolutionarily-conserved cysteine bound to the iron center of heme B.
Since the iron in heme B containing proteins is bound to the four nitrogens of the porphyrin (forming a plane) and a single electron donating atom of the protein, the iron is often in a pentacoordinate state. When oxygen or the toxic carbon monoxide is bound the iron becomes hexacoordinated.
The correct structures of heme B and heme S were first elucidated by German chemist Hans Fischer. | 1 | Applied and Interdisciplinary Chemistry |
If an equation of state is available, it can be used to predict the values of the thermal expansion at all the required temperatures and pressures, along with many other state functions. | 0 | Theoretical and Fundamental Chemistry |
The first total synthesis was accomplished in 2000 by the Danishefsky group at Columbia University, with a number of other syntheses following shortly thereafter by Williams, Ganesan, Fuji, Carreira, Horne, Overman, and most recently Trost.
From a synthetic point of view, the most challenging structural features of the molecule are the C3 spirocyclic ring juncture and the adjacent prenyl-substituted carbon. Approaches toward preparing the skeleton of spirotryprostatin B have varied considerably.
Danishefsky spirotryprostatin B synthesis
In the Danishefsky synthesis, an amine derived from tryptophan was condensed with an aldehyde, triggering a Mannich-type reaction wherein the pendant oxindole acted as a nucleophile toward the intermediate iminium species.
Williams spirotryprostatin B synthesis
The synthesis by the Williams group utilized a 3-component coupling reaction. A secondary amine was combined with an aldehyde to form an intermediate azomethine ylide, which underwent a 1,3-dipolar cycloaddition with an unsaturated oxindole also present in the reaction mixture.
Ganesan spirotryprostatin B synthesis
Ganesan made use of a biomimetic strategy in his synthesis of spirotryprostatin B. An indole was treated with N-bromosuccinimide to trigger an oxidative rearrangement, forming the quaternary stereocenter in a diastereoselective manner.
Fuji spirotryprostatin B synthesis
In the synthesis developed by the Fuji group, the stereochemistry at the spirocyclic carbon was established by a nitroolefination reaction. An oxindole with pendant prenyl group was reacted with a nitroolefin bearing a chiral leaving group.
Carreira spirotryprostatin B synthesis
The Carreira group made use of a magnesium iodide promoted annulation reaction in their approach toward spirotryprostatin B. An oxindole bearing a cyclopropane was reacted with an imine in the presence of the magnesium iodide, triggering the ring-expansion reaction.
Horne spirotryprostatin B synthesis
Horne's synthesis of spirotryprostatin B also made use of a Mannich-type process, wherein a chloro-indole served as the pro-nucleophile. The cyclization was triggered by treating the pendant imine with the acyl chloride derived from proline. The resulting iminium species was attacked by the chloro-indole, forming the spirocyclic bond.
Overman spirotryprostatin B synthesis
The Overman group utilized a Heck reaction to prepare the molecule. An iodo-aniline with a tethered alkene was subjected to palladium catalysis. The intermediate palladium-allyl species was intercepted by the pendant amide nitrogen to generate the prenyl stereocenter in the same reaction.
Trost spirotryprostatin B synthesis
In the synthesis developed by the Trost group, the stereochemistry at the spirocyclic ring juncture is established by a decarboxylation-prenylation sequence, reminiscent of the Carroll reaction. Here, a prenyl ester serves as both the nucleophile and electrophile precursor. Upon treatment with a chiral palladium catalyst the prenyl group ionizes and decarboxylates. The resulting ion pair subsequently recombines to generate the prenylated product. Notably, double bond migration occurs and the prenyl group is attacked at the oxindole carbon. | 0 | Theoretical and Fundamental Chemistry |
The first such attempt is found in the Swain–Scott equation derived in 1953:
This free-energy relationship relates the pseudo first order reaction rate constant (in water at 25 °C), k, of a reaction, normalized to the reaction rate, k, of a standard reaction with water as the nucleophile, to a nucleophilic constant n for a given nucleophile and a substrate constant s that depends on the sensitivity of a substrate to nucleophilic attack (defined as 1 for methyl bromide).
This treatment results in the following values for typical nucleophilic anions: acetate 2.7, chloride 3.0, azide 4.0, hydroxide 4.2, aniline 4.5, iodide 5.0, and thiosulfate 6.4. Typical substrate constants are 0.66 for ethyl tosylate, 0.77 for β-propiolactone, 1.00 for 2,3-epoxypropanol, 0.87 for benzyl chloride, and 1.43 for benzoyl chloride.
The equation predicts that, in a nucleophilic displacement on benzyl chloride, the azide anion reacts 3000 times faster than water. | 0 | Theoretical and Fundamental Chemistry |
Esketamine is approximately twice as potent an anesthetic as racemic ketamine.
In mice, the rapid antidepressant effect of arketamine was greater and lasted longer than that of esketamine. The usefulness of arketamine over esketamine has been supported by other researchers.
Esketamine inhibits dopamine transporters eight times more than arketamine. This increases dopamine activity in the brain. At doses causing the same intensity of effects, esketamine is generally considered to be more pleasant by patients. Patients also generally recover mental function more quickly after being treated with pure esketamine, which may be a result of the fact that it is cleared from their system more quickly. This is however in contradiction with arketamine being devoid of psychotomimetic side effects.
Unlike arketamine, esketamine does not bind significantly to sigma receptors. Esketamine increases glucose metabolism in the frontal cortex, while arketamine decreases glucose metabolism in the brain. This difference may be responsible for the fact that esketamine generally has a more dissociative or hallucinogenic effect while arketamine is reportedly more relaxing. However, another study found no difference between racemic ketamine and esketamine on the patient's level of vigilance. Interpretation of this finding is complicated by the fact that racemic ketamine is 50% esketamine. | 0 | Theoretical and Fundamental Chemistry |
Mycorrhizae, symbiotic fungal-plant communities, are important to the success of revegetation efforts. Most woody plant species need these root-fungi communities to thrive, and nursery or greenhouse transplants may not have sufficient or correct mycorrhizae for good survival. Mycorhizal communities are particularly beneficial to nitrogen-fixing woody plants, C4-grasses, and soil environments low in phosphorus. Two types of mycorrhizal fungi aid in restoration: ectomycorrhizal fungi and arbuscular mycorrhizal fungi. | 1 | Applied and Interdisciplinary Chemistry |
A number of adhesion GPCRs may have important roles within the immune system. In particular, members the EGF-TM7 subfamily which possess N-terminal EGF-like domains are predominantly restricted to leukocytes suggesting a putative role in immune function. The human EGF‑TM7 family is composed of CD97, EMR1 (F4/80 receptor orthologue) EMR2, EMR3 and EMR4 (a probable pseudogene in humans). The human-restricted EMR2 receptor, is expressed by myeloid cells including monocytes, dendritic cells and neutrophils has been shown to be involved in the activation and migration of human neutrophils and upregulated in patients with systemic inflammatory response syndrome (SIRS). Details of EMR1, CD97 needed. The adhesion‑GPCR brain angiogenesis inhibitor 1 (BAI1) acts as a phosphatidylserine receptor playing a potential role in the binding and clearance of apoptotic cells, and the phagocytosis of Gram-negative bacteria. GPR56 has been shown to a marker for inflammatory NK cell subsets and to be expressed by cytotoxic lymphocytes. | 1 | Applied and Interdisciplinary Chemistry |
*Lovelock, James. The Independent. [https://web.archive.org/web/20060408121826/http://comment.independent.co.uk/commentators/article338830.ece The Earth is about to catch a morbid fever], 16 January 2006.
*Lovelock, James (2006), interviewed in How to think about science, CBC Ideas (radio program), broadcast January 3, 2008. [http://www.cbc.ca/ideas/episodes/2009/01/02/how-to-think-about-science-part-1---24-listen/ Link] | 0 | Theoretical and Fundamental Chemistry |
In the Euclidean plane, we have the following possibilities.
*; [ ] Identity
:Two reflections in the same mirror restore each point to its original position. All points are left fixed. Any pair of identical mirrors has the same effect.
*; [] Reflection
:As Alice found through the looking-glass, a single mirror causes left and right hands to switch. (In formal terms, topological orientation is reversed.) Points on the mirror are left fixed. Each mirror has a unique effect.
*; [] Rotation
:Two distinct intersecting mirrors have a single point in common, which remains fixed. All other points rotate around it by twice the angle between the mirrors. Any two mirrors with the same fixed point and same angle give the same rotation, so long as they are used in the correct order.
*; [] Translation
:Two distinct mirrors that do not intersect must be parallel. Every point moves the same amount, twice the distance between the mirrors, and in the same direction. No points are left fixed. Any two mirrors with the same parallel direction and the same distance apart give the same translation, so long as they are used in the correct order.
*; [] Glide reflection
:Three mirrors. If they are all parallel, the effect is the same as a single mirror (slide a pair to cancel the third). Otherwise we can find an equivalent arrangement where two are parallel and the third is perpendicular to them. The effect is a reflection combined with a translation parallel to the mirror. No points are left fixed. | 0 | Theoretical and Fundamental Chemistry |
Sensor-based ore sorting is financially especially attractive for low grade or marginal ore or waste dump material. This described scenario describes that waste dump material or marginal ore is sorted and added to the run-of-mine production. The needed capacity for the sensor-based ore sorting step is less in this case such as the costs involved. Requirement is that two crude material streams are fed in parallel, requiring two crushing stations. Alternatively, marginal and high grade ore can be buffered on an intermediate stockpile and dispatched in an alternating operation. The latter option has the disadvantage that the planned production time, the loading, of the sensor-based ore sorter is low, unless a significant intermediate stockpile or bunker is installed. Treating the marginal ore separately has the advantage that less equipment is needed since the processed material stream is lower, but it has the disadvantage that the potential of the technology is not unfolded for the higher grade material, where sensor-based sorting would also add benefit. | 0 | Theoretical and Fundamental Chemistry |
Metal-catalyzed cyclopropanations are chemical reactions that result in the formation of a cyclopropane ring from a metal carbenoid species and an alkene. In the Simmons–Smith reaction the metal involved is zinc. Metal carbenoid species can be generated through the reaction of a diazo compound with a transition metal). The intramolecular variant of this reaction was first reported in 1961. Rhodium carboxylate complexes, such as dirhodium tetraacetate, are common catalysts. Enantioselective cyclopropanations have been developed. | 0 | Theoretical and Fundamental Chemistry |
Nuclease protection assay is a laboratory technique used in biochemistry and genetics to identify individual RNA molecules in a heterogeneous RNA sample extracted from cells. The technique can identify one or more RNA molecules of known sequence even at low total concentration. The extracted RNA is first mixed with antisense RNA or DNA probes that are complementary to the sequence or sequences of interest and the complementary strands are hybridized to form double-stranded RNA (or a DNA-RNA hybrid). The mixture is then exposed to ribonucleases that specifically cleave only single-stranded RNA but have no activity against double-stranded RNA. When the reaction runs to completion, susceptible RNA regions are degraded to very short oligomers or to individual nucleotides; the surviving RNA fragments are those that were complementary to the added antisense strand and thus contained the sequence of interest. | 1 | Applied and Interdisciplinary Chemistry |
Only recently also other extraction applications have been investigated, e.g. the large scale recovery of apolar organics on offshore oil platforms using the so-called Macro-Porous Polymer Extraction (MPPE) Technology. In such an application, where the SIR particles are contained in a packed bed, flow rates from 0.5 m h upward without maximum flow restrictions can apparently be treated cost competitive to air stripping/activated carbon, steam stripping and bio treatment systems, according to the technology developer. Additional investigations, mostly done in an academic environment, include polar organics like amino-alcohols, organic acids, amino acids, flavonoids, and aldehydes on a bench-scale or pilot-scale. Also, the application of SIRs for the separation of more polar solutes, such as for instance ethers and phenols, has been investigated in the group of A.B. de Haan. | 0 | Theoretical and Fundamental Chemistry |
The Born series is the expansion of different scattering quantities in quantum scattering theory in the powers of the interaction potential (more precisely in powers of where is the free particle Green's operator). It is closely related to Born approximation, which is the first order term of the Born series. The series can formally be understood as power series introducing the coupling constant by substitution . The speed of convergence and radius of convergence of the Born series are related to eigenvalues of the operator . In general the first few terms of the Born series are good approximation to the expanded quantity for "weak" interaction
and large collision energy. | 0 | Theoretical and Fundamental Chemistry |
Drug discovery depends on methods by which many different chemicals are assayed for their activity. These chemicals are stored as physical quantities in a chemical library or libraries which are often assembled from both outside vendors and internal chemical synthesis efforts. These chemical libraries are used in high-throughput screening in the drug discovery hit to lead process.
The chemical libraries in larger pharmaceutical companies are a critical part of the discovery process. These chemicals are stored in environmentally controlled conditions in small or large containers, often labeled with codes that pass back into a database. Each chemical in the storage bank must be monitored for shelf life, quantity, purity and other parameters, and its banked location. In some companies, the compounds can also include biological compounds, such as purified proteins or nucleic acids. The management of these chemical libraries, including renewal of outdated chemicals, databases containing the information, robotics often involved in fetching chemicals, and quality control of the storage environment is called Compound Management or Compound Control. Compound Management is often a significant expense, as well as career for one or more individuals who manage a chemical library at a research site.
There are many books and journal articles devoted entirely or in part to compound management. It has become a critical technological component for high-throughput screening and chemical genomics. There are great challenges to be faced in the necessity of compound management, which are being surmounted by concerted efforts in the public and private domain. In 2008, authors at the National Institutes of Health's Chemical Genomics Center have released a paper showing the necessity of a highly automated, reliable and parallel compound management platform, in order to serve over 200,000 different compounds.
In short, Compound Management requires inventory control of small molecules and biologics needed for assays and experiments, especially in high-throughput screening. It utilizes knowledge of chemistry, robotics, biology, and database management. The manager must also be acutely aware of safety standards in the handling and storing of radioactive, volatile, flammable and unstable compounds. Often, in large pharmaceutical companies, the chemical and biological compounds contained in compound libraries can number in the millions, making compound management and compound control important contributors to research and drug discovery. | 1 | Applied and Interdisciplinary Chemistry |
Nickel tetracarbonyl and iron pentacarbonyl can be prepared according to the following equations by reaction of finely divided metal with carbon monoxide:
:Ni + 4 CO → Ni(CO) (1 bar, 55 °C)
:Fe + 5 CO → Fe(CO) (100 bar, 175 °C)
Nickel tetracarbonyl is formed with carbon monoxide already at 80 °C and atmospheric pressure, finely divided iron reacts at temperatures between 150 and 200 °C and a carbon monoxide pressure of 50–200 bar. Other metal carbonyls are prepared by less direct methods. | 0 | Theoretical and Fundamental Chemistry |
Qualitative inorganic analysis is now used only as a pedagogical tool. Modern techniques such as atomic absorption spectroscopy and ICP-MS are able to quickly detect the presence and concentrations of elements using a very small amount of sample. | 0 | Theoretical and Fundamental Chemistry |
Many variations of Josiphos ligands have been reported. One family is prepared from Ugi's amine.
An important improvement on initial syntheses has been using N(CH) as a leaving group over acetate, although an acetic acid solvent gives better yields. | 0 | Theoretical and Fundamental Chemistry |
Ampicillin is an antibiotic belonging to the aminopenicillin class of the penicillin family. The drug is used to prevent and treat a number of bacterial infections, such as respiratory tract infections, urinary tract infections, meningitis, salmonellosis, and endocarditis. It may also be used to prevent group B streptococcal infection in newborns. It is used by mouth, by injection into a muscle, or intravenously.
Common side effects include rash, nausea, and diarrhea. It should not be used in people who are allergic to penicillin. Serious side effects may include Clostridium difficile colitis or anaphylaxis. While usable in those with kidney problems, the dose may need to be decreased. Its use during pregnancy and breastfeeding appears to be generally safe.
Ampicillin was discovered in 1958 and came into commercial use in 1961. It is on the World Health Organization's List of Essential Medicines. The World Health Organization classifies ampicillin as critically important for human medicine. It is available as a generic medication. | 0 | Theoretical and Fundamental Chemistry |
Phosphinous acids exist mainly as minor tautomers of secondary phosphine oxides. For example diphenylphosphinous acid, which is not detectable directly, is invoked as the tautomer of diphenylphosphine oxide.
Highly electron-withdrawing substituents stabilize the phosphinous acid tautomer as illustrated by (CF)POH. | 0 | Theoretical and Fundamental Chemistry |
Stress corrosion cracking (SCC) is the growth of crack formation in a corrosive environment. It can lead to unexpected and sudden failure of normally ductile metal alloys subjected to a tensile stress, especially at elevated temperature. SCC is highly chemically specific in that certain alloys are likely to undergo SCC only when exposed to a small number of chemical environments. The chemical environment that causes SCC for a given alloy is often one which is only mildly corrosive to the metal. Hence, metal parts with severe SCC can appear bright and shiny, while being filled with microscopic cracks. This factor makes it common for SCC to go undetected prior to failure. SCC often progresses rapidly, and is more common among alloys than pure metals. The specific environment is of crucial importance, and only very small concentrations of certain highly active chemicals are needed to produce catastrophic cracking, often leading to devastating and unexpected failure.
The stresses can be the result of the crevice loads due to stress concentration, or can be caused by the type of assembly or residual stresses from fabrication (e.g. cold working); the residual stresses can be relieved by annealing or other surface treatments. Unexpected and premature failure of chemical process equipment, for example, due to stress corrosion cracking constitutes a serious hazard in terms of safety of personnel, operating facilities and the environment. By weakening the reliability of these types of equipment, such failures also adversely affect productivity and profitability. | 1 | Applied and Interdisciplinary Chemistry |
According to Ohta (1994, pp. 90–91) the ranking and scientific analysis of energy quality was first proposed in 1851 by William Thomson under the concept of "availability". This concept was continued in Germany by Z. Rant, who developed it under the title, "die Exergie" (the exergy). It was later continued and standardised in Japan. Exergy analysis now forms a common part of many industrial and ecological energy analyses. For example, I.Dincer and Y.A. Cengel (2001, p. 132) state that energy forms of different qualities are now commonly dealt with in steam power engineering industry. Here the "quality index" is the relation of exergy to the energy content (Ibid.). However energy engineers were aware that the notion of heat quality involved the notion of value – for example A. Thumann wrote, "The essential quality of heat is not the amount but rather its value" (1984, p. 113) – which brings into play the question of teleology and wider, or ecological-scale goal functions. In an ecological context S.E. Jorgensen and G.Bendoricchio say that exergy is used as a goal function in ecological models, and expresses energy "with a built-in measure of quality like energy" (2001, p. 392). | 0 | Theoretical and Fundamental Chemistry |
An annulation is defined as a transformation of one or more acyclic precursors resulting in the fusion of a new ring via two newly generated bonds. These strategies can be used to create aromatic systems from acyclic precursors in a single step, with many substituents already in place. A common synthetic annulation reaction is the Robinson annulation. It is a useful reactions for forming six-membered rings and generating polycyclic compounds. It is the combination of the Michael Addition and the Aldol Condensation reaction. | 0 | Theoretical and Fundamental Chemistry |
Theophrastus (390–280 BC) was a disciple of Aristotle and a philosopher of natural history, considered by historians as the Father of Botany. He wrote a treatise entitled Historia Plantarium about 300 BC. It was the first attempt to organize and classify plants, plant lore, and botanical morphology in Greece. It provided physicians with a rough taxonomy of plants and details of medicinal herbs and herbal concoctions. | 1 | Applied and Interdisciplinary Chemistry |
A solvated electron is a free electron in a solution, in which it behaves like an anion. An electron's being solvated in a solution means it is bound by the solution. The notation for a solvated electron in formulas of chemical reactions is "e". Often, discussions of solvated electrons focus on their solutions in ammonia, which are stable for days, but solvated electrons also occur in water and many other solvents in fact, in any solvent that mediates outer-sphere electron transfer. The solvated electron is responsible for a great deal of radiation chemistry. | 0 | Theoretical and Fundamental Chemistry |
For quasi-static and reversible processes, the first law of thermodynamics is:
where δQ is the heat supplied to the system and δW is the work done by the system. | 0 | Theoretical and Fundamental Chemistry |
Neurons from several brain regions, such as the neocortex, substantia nigra, and hippocampus have been found to contain autapses.
Autapses have been observed to be relatively more abundant in GABAergic basket and dendrite-targeting cells of the cat visual cortex compared to spiny stellate, double bouquet, and pyramidal cells, suggesting that the degree of neuron self-innervation is cell-specific. Additionally, dendrite-targeting cell autapses were, on average, further from the soma compared to basket cell autapses.
80% of layer V pyramidal neurons in developing rat neocortices contained autaptic connections, which were located more so on basal dendrites and apical oblique dendrites rather than main apical dendrites. The dendritic positions of synaptic connections of the same cell type were similar to those of autapses, suggesting that autaptic and synaptic networks share a common mechanism of formation. | 1 | Applied and Interdisciplinary Chemistry |
Many recipes for medicines included herbs, minerals, and pieces of animals (meats, fats, skins) that were ingested, made into paste for external use, or used as aromatherapy. Some of these are similar to natural remedies used today, including catnip, chamomile, fennel, mint, garlic, and witch hazel. Many other ingredients used in the past such as urine, fecal matter, earwax, human fat, and saliva, are no longer used and are generally considered ineffective or unsanitary. Trial and error were the main source for finding successful remedies, as little was known about the chemistry of why certain treatments worked. For instance, it was known that drinking coffee could help cure headaches, but the existence and properties of caffeine itself was still a mystery. | 1 | Applied and Interdisciplinary Chemistry |
*Epinephrine induces platelet aggregation, and so does hepatocyte growth factor (HGF). Thus, they are physiological agonists to each other. | 1 | Applied and Interdisciplinary Chemistry |
HIRs require long exposure to relatively high light levels. The degree of response will depend on the level of light. They are characterised by the fact that they do not follow the law of reciprocity and depend on the rate of photons hitting the leaf surface, as opposed to the total light levels. This means that neither long exposure to dim levels of light nor very bright flashes of light are enough to trigger these responses. HIR does not show red and far red photoreversibility and does not obey the law of reciprocity. | 0 | Theoretical and Fundamental Chemistry |
In petroleum geology, the maturity of a rock is a measure of its state in terms of hydrocarbon generation. Maturity is established using a combination of geochemical and basin modelling techniques.
Rocks with high total organic carbon, (termed source rocks), will alter under increasing temperature such that the organic molecules slowly mature into hydrocarbons (see diagenesis). Source rocks are therefore broadly categorised as immature (no hydrocarbon generation), sub-mature (limited hydrocarbon generation), mature (extensive hydrocarbon generation) and overmature (most hydrocarbons have been generated).
The maturity of a source rock can also be used as an indicator of its hydrocarbon potential. That is, if a rock is sub-mature, then it has a much higher potential to generate further hydrocarbons than one that is overmature. | 0 | Theoretical and Fundamental Chemistry |
It was not until 1987 when two chemists, Hedrick and Schlemper, from the University of Freiburg proposed the use of phosphazene bases to speed up the reaction and lower the polydispersity index. Up until 2023, three different phosphazene bases have been used in PPA polymerization. Moreover, most of the published research articles describing PPA synthesis between 2008 and 2023 revolve around the usage of LAP, rendering it the most common and effective polymerization technique. | 0 | Theoretical and Fundamental Chemistry |
A quantum heat engine is a device that generates power from the heat flow between hot and cold reservoirs.
The operation mechanism of the engine can be described by the laws of quantum mechanics.
The first realization of a quantum heat engine was pointed out by Scovil and Schulz-DuBois in 1959, showing the connection of efficiency of the Carnot engine and the 3-level maser.
Quantum refrigerators share the structure of quantum heat engines with the purpose of pumping heat from a cold to a hot bath consuming power
first suggested by Geusic, Schulz-DuBois, De Grasse and Scovil. When the power is supplied by a laser the process is termed optical pumping or laser cooling, suggested by Wineland and Hänsch.
Surprisingly heat engines and refrigerators can operate up to the scale of a single particle thus justifying the need for a quantum theory termed quantum thermodynamics. | 0 | Theoretical and Fundamental Chemistry |
The Chesapeake Bay ( ) is the largest estuary in the United States. The Bay is located in the Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula, including parts of the Eastern Shore of Maryland, the Eastern Shore of Virginia, and the state of Delaware. The mouth of the Bay at its southern point is located between Cape Henry and Cape Charles. With its northern portion in Maryland and the southern part in Virginia, the Chesapeake Bay is a very important feature for the ecology and economy of those two states, as well as others surrounding within its watershed. More than 150 major rivers and streams flow into the Bay's drainage basin, which covers parts of six states, New York, Pennsylvania, Delaware, Maryland, Virginia, and West Virginia, and all of Washington, D.C.
The Bay is approximately long from its northern headwaters in the Susquehanna River to its outlet in the Atlantic Ocean. It is wide at its narrowest (between Kent County's Plum Point near Newtown in the east and the Harford County western shore near Romney Creek) and at its widest (just south of the mouth of the Potomac River which divides Maryland from Virginia). Total shoreline including tributaries is , circumnavigating a surface area of . Average depth is , reaching a maximum of . The Bay is spanned twice, in Maryland by the Chesapeake Bay Bridge from Sandy Point (near Annapolis) to Kent Island and in Virginia by the Chesapeake Bay Bridge–Tunnel connecting Virginia Beach to Cape Charles.
Known for both its beauty and bounty, the Bay has become "emptier", with fewer crabs, oysters and watermen (fishermen) since the mid-20th century. Nutrient pollution and urban runoff have been identified as major components of impaired water quality in the bay stressing ecosystems and compounding the decline of shellfish due to overharvesting. Restoration efforts that began in the 1990s have continued into the 21st century and show potential for growth of the native oyster population. The health of the Chesapeake Bay improved in 2015, marking three years of gains over a four-year period. Slight improvements in water quality were observed in 2021, compared to indicators measured in 2020. The bay is experiencing other environmental concerns, including climate change which is causing sea level rise that erodes coastal areas and infrastructure and changes to the marine ecosystem. | 1 | Applied and Interdisciplinary Chemistry |
Small interfering (siRNA) are short, 19-23 base-pair (with a 3 overhang of two nucleotides), double-stranded pieces of RNA that participate in the RNA-induced silencing complex (RISC) for gene silencing. Specifically, siRNA is bound by the RISC complex where it is unwound using ATP hydrolysis. It is then used as a guide by the enzyme "Slicer" to target mRNAs for degradation based on complementary base-pairing to the target mRNA. As a therapeutic, siRNA is able to be delivered locally, through the eye or nose, to treat various diseases. Local delivery benefits from simple formulation and drug delivery and high bioavailability of the drug. Systemic delivery is necessary to target cancers and other diseases. Targeting the siRNA when delivered locally is one of the main challenges in siRNA therapeutics. While it is possible to use intravenous injection to deliver siRNA therapies, concerns have been raised about the large volumes used in the injection, as these must often be ~20-30% of the total blood volume. Other methods of delivery include liposome packaging, conjugation to membrane-permeable peptides, and direct tissue/organ electroporation. Additionally, it has been found that exogeneous siRNAs only last a few days (a few weeks at most in non-dividing cells) in vivo'. If siRNA is able to successfully reach its target, it has the potential to therapeutically regulate gene expression through its ability to base-pair to mRNA targets and promote their degradation through the RISC system Currently, siRNA-based therapy is in a phase I clinical trial for the treatment of age-related macular degeneration, although it is also being explored for use in cancer therapy. For instance, siRNA can be used to target mRNAs that code for proteins that promote tumor growth such as the VEGF receptor and telomerase enzyme. | 1 | Applied and Interdisciplinary Chemistry |
The dimerization partner, RB-like, E2F and multi-vulval class B (DREAM) complex is a protein complex responsible for the regulation of cell cycle-dependent gene expression. The complex is evolutionarily conserved, although some of its components vary from species to species. In humans, the key proteins in the complex are RBL1 (p107) and RBL2 (p130), both of which are homologs of RB (p105) and bind repressive E2F transcription factors E2F4 and E2F5; DP1, DP2 and DP3, dimerization partners of E2F; and MuvB, which is a complex of LIN9/37/52/54 and RBBP4. | 1 | Applied and Interdisciplinary Chemistry |
Xylene is used in the laboratory to make baths with dry ice to cool reaction vessels, and as a solvent to remove synthetic immersion oil from the microscope objective in light microscopy. In histology, xylene is the most widely used clearing agent. Xylene is used to remove paraffin from dried microscope slides prior to staining. After staining, microscope slides are put in xylene prior to mounting with a coverslip. | 1 | Applied and Interdisciplinary Chemistry |
Mammalian cell lines such as Chinese hamster V79 cells, Chinese hamster ovary (CHO) cells or mouse lymphoma cells may be used to test for mutagenesis. Such systems include the HPRT assay for resistance to 8-azaguanine or 6-thioguanine, and ouabain-resistance (OUA) assay.
Rat primary hepatocytes may also be used to measure DNA repair following DNA damage. Mutagens may stimulate unscheduled DNA synthesis that results in more stained nuclear material in cells following exposure to mutagens. | 0 | Theoretical and Fundamental Chemistry |
The modification required to biosynthesize mature chloroeremomycin include: oxidative cross-linking of aromatic rings, hydroxylation and chlorination of the two Tyr residues, methylation of Leu, and glycosylation at aa4 and aa6.
The oxidative crosslinks are catalyzed by enzymes OxyA-C. The glycosylations are catalyzed by enzymes GtfA-C (coded by Orf11-13 respectively). The chlorinations are performed by enzymes encoded by Orf10 and 18. | 0 | Theoretical and Fundamental Chemistry |
In the estimation of human exposures to environmental chemicals, the following systemic errors have been known to occur:
* an ever increasing number of chemicals registered for use and difficulty of regulatory agencies to keep track. Many producers use the term confidential business information to withhold information, so exposure data are per se unavailable even though under TSCA, the US EPA may as of 2016, review and determine if a company´s claim is valid.
* assessments are difficult to be kept up-to-date;
* underestimates of exposure occur because of inadequate assumptions about human behaviors and co-exposures ;
* evolving or insufficient models of toxicokinetics | 1 | Applied and Interdisciplinary Chemistry |
An example of an alcoholic glycoside is salicin, which is found in the genus Salix. Salicin is converted in the body into salicylic acid, which is closely related to aspirin and has analgesic, antipyretic, and anti-inflammatory effects. | 0 | Theoretical and Fundamental Chemistry |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.