Number Of Related Molecules Research Articles

S100A4 in Spinal Substantia Gelatinosa from Dorsal Root Ganglia Modulates Neuropathic Pain in a Rodent Spinal Nerve Injury Model.

PurposeTo detect the spatio-temporal expression of S100A4 in a spinal nerve ligation (SNL) rat model. Also to figure out which other molecules directly interact with S100A4 to explore the possible mechanisms which might be involved in neuropathic pain.MethodsSeven-week-old male SD rats were used for the SNL model construction. Immunofluorescence and Western blotting were used to detect the spatio-temporal expression of S100A4 in the model. S100A4 was co-labeled with a number of related molecules and marker molecules that can distinguish between cell types. After intrathecal injection of S100A4 neutralizing antibody, the behavioral changes of SNL rats were recorded, and molecular changes compared. The direct interaction between S100A4 and other related molecules was verified by co-immunoprecipitation (co-IP) to explore its possible mechanism.ResultsAfter spinal nerve ligation, the content of S100A4 in the dorsal root ganglion (DRG) and spinal dorsal horn increased significantly. Intrathecal injection of S100A4 neutralizing antibody could effectively relieve the mechanical pain in rats. co-IP revealed a direct interaction between S100A4 and RAGE.ConclusionThe content of S100A4 in the DRG and spinal dorsal horn of SNL rats increased, compared with that of the control group. Intrathecal injection of S100A4 neutralizing antibody could effectively relieve the mechanical pain in SNL rats. S100A4 may be involved in the production of neuropathic pain through RAGE or other ways, but the specific mechanism needs to be further studied.

Confined viscous liquids: Interfacial versus finite size effects

Confining a supercooled liquid to spaces of several nanometer in diameter can lead to dramatic changes in the relaxation dynamics of the material. In many cases, the effect is reported as a confinement induced shift of the glass transition temperature Tg. Both positive and negative values for ΔT g have been observed and the length scale of the confining geometry is considered the main variable. We review the dynamics of glass-forming liquids in both hard and soft confinement of <10 nm spaces, with focus on results from solvation dynamics experiments. It is shown that the interface is instrumental in determinig the dynamics, giving rise to reaxation time gradients across the cooperativity length scale of the liquid. Depending on the interfacial conditions, dynamics can become faster or slower for the same liquid, same size of confinement, and identical experimental technique used. No indications of true finite size effects are observed, and the pore or droplet size is relevant only indirectly through the relative number of molecules near the surface.

"Through Space" Triplet Energy Transfer: Movement of Electrons through the Hemicarcerand Skeleton

A great deal of interest has developed concerning the influence of the nature of the intervening media on electron transfer reactions in which electrons move from donor to acceptor sites separated by “insulating” material.’ Details of such processes can be probed by the study of triplet energy transfer based on the proposal of Dexter that transfer involves exchange of electrons between energy donor and acceptor.* Recently this approach was verified when Closs showed that energy transfer can occur between chromophoric groups separated by long distances, but connected by networks of single bonds.3 The rates of energy transfer within a number of related molecules, with varying interchromophoric distances and orientations, were correlated quantitatively with rates of charge transfer involving both electron and hole transfer in the same molecular ~ y s t e m . ~ The results lent increased credibility to the Dexter mechanism but did not resolve the question as to whether or not the intervening saturated structures played a special role in the process (through-bond mechanism). Here we describe the unambiguous observation of triplet energy transfer between unconnected systems separated by a molecular barrier (throughspace mechanism). An encapsulating host molecule (“hemicarcerand”) was used to separate the donor and acceptor in solution so that the through-bond mechanism as it is commonly defined would not be operative, but the path of closest approach could still be estimated with good certainty. Hemicarcerands are closedsurface hosts with rigid, physically isolated interiors that form kinetically stable complexes when large energetic barriers prevent guest egresse5 Work by Cram et al. in which the normally highly reactive cyclobutadiene was created inside a hemicarcerand confirms that species deeply buried within hemicarcerand interiors have no “bond-forming’’ contact with the extemal milieu.6 Therefore, a triplet energy donor placed inside a hemicarcerand would not come into direct contact with the energy acceptor. Both CPK molecular model examination and force field calculations7 predict that acetophenone would fit tightly within

ChemInform Abstract: MOLECULAR PARAMETERS OF EXCITED MOLECULES AND IONS. PART V. THE METHYL RADICAL AND ITS IONS

Abstract The Franck—Condon principle was applied quantitatively to the first photoelectron bands of the CH 3 and CD 3 radicals. The intensity distributions within the fine structures of these bands can be explained satisfactorily by invoking excitations of the out-of-plane vibration ν 2 and the angle bending degenerate vibration ν 4 . The results of computation do support the planarity of the methyl radical and the methyl cation. In addition, the bond lengths of CH 3 and CH + 3 are expected to have similar magnitudes by considering the vibrational intensity appeared in the corresponding photoelectron spectra. Moreover, a Franck—Condon factor calculation on the photoelectron spectrum of the methyl anion suggested that the ion is nonplanar and has a bond angle of 100° ± 4°. Force constant calculations were carried out on CH 3 , CH + 3 and CH − 3 as well as a number of related molecules with the use of the Urey—Bradley force field. The variations in the magnitudes of the force constants obtained were discussed in the light of the bonding properties and the atomic charge distributions within these molecules.

Molecular parameters of excited molecules and ions: Part V. The methyl radical and its ions

The Franck—Condon principle was applied quantitatively to the first photoelectron bands of the CH 3 and CD 3 radicals. The intensity distributions within the fine structures of these bands can be explained satisfactorily by invoking excitations of the out-of-plane vibration ν 2 and the angle bending degenerate vibration ν 4. The results of computation do support the planarity of the methyl radical and the methyl cation. In addition, the bond lengths of CH 3 and CH + 3 are expected to have similar magnitudes by considering the vibrational intensity appeared in the corresponding photoelectron spectra. Moreover, a Franck—Condon factor calculation on the photoelectron spectrum of the methyl anion suggested that the ion is nonplanar and has a bond angle of 100° ± 4°. Force constant calculations were carried out on CH 3, CH + 3 and CH − 3 as well as a number of related molecules with the use of the Urey—Bradley force field. The variations in the magnitudes of the force constants obtained were discussed in the light of the bonding properties and the atomic charge distributions within these molecules.

Microwave Spectrum and Structure of Nitric Acid

The microwave spectra of five further isotopic species of nitric acid, H18ONO2, cis-HON18OO, trans-HONO18O, cis-HO15N18OO, and D15NO3, have been investigated. The data have been used to refine the previous structural determination of Millen and Morton. In the calculation of structure, particular consideration has been given to the use of ground-state moments of inertia in Kraitchman's equations for near-oblate planar molecules. The structure was calculated using several different methods, including the double-substitution method due to Pierce, in order to substantiate the following structural parameters: O–H=0.964, (H)O–N=1.406, cis–N–O=1.211, trans-N–O=1.199 Å, ∠HON=102°9′, ∠cis-ONO=115°53′, ∠trans-ONO=113°51′, and O···O (NO2 group)=2.184 Å. This determination clearly demonstrates a 2° tilt of the NO2 group away from the hydrogen atom. The NO2 parameters are close to those found in a number of related molecules, but there is some evidence that the cis-NO bond in HNO3 is slightly longer than the trans-NO bond. The NOH configuration is very similar to that found in formaldoxime. Further evidence for the exact planarity of nitric acid is given. Stark-effect measurements limit the out-of-plane component of the dipole moment μC to a value less than 1.1×10−3 D. The other components have been redetermined to have the values μA=1.99 D and μB=0.88 D, giving a total dipole moment μ=2.17±0.02 D.

EVALUATION OF INTRADERMAL SKIN TESTS IN PENICILLIN HYPERSENSITIVITY.

To further evaluate the accuracy of the penicilloyl-polylsine (PPL) skin test in detecting persons allergic to penicillin, this test was performed on 22 persons who had demonstrated hypersensitivity reactions to benzathine penicillin G (Bicillin) administered three months previously. Suitable control subjects were selected and skin tested with PPL. In the same subjects skin testing with penicillin G and a number of related molecules was also performed. Twenty of 22 subjects with a history of clinical allergy to benzathine penicillin gave positive PPL skin tests, whereas only two of 40 control subjects reacted to the same antigen. Penicillin G, as well as other antigens tested, was considerably less effective in detecting the hypersensitive individual than was PPL.

Normal Paraffin Hydrocarbons in Recent Sediments from San Francisco Bay, California: ABSTRACT

Post-Pleistocene sediments of San Francisco Bay, California, have been analyzed for the presence of normal paraffin hydrocarbons. Gas-liquid chromatography was used to examine sediment extracts for normal paraffins containing 8 through 13 carbon atoms per molecule (intermediate molecular weights). Liquid-solid chromatography, infrared and mass spectrometry were used to determine in sediment extracts normal paraffins containing more than 18 carbon atoms per molecule (high molecular weights). Knowledge of normal paraffins in recently deposited sediments may be useful in explaining the origin of crude oils. The results of analyses of sediments of San Francisco Bay show that normal paraffins containing 8 through 13 carbon atoms are probably absent, or each is present in a concentration less than one part per million dried sediment. Concentrations from 3 to 6 parts per million dried sediment were determined for the normal paraffins containing more than 18 carbon atoms per molecule. Among the normal paraffins containing 23-35 carbon atoms per molecule, the relative number of molecules having an odd number of carbon atoms is greater than the relative number of molecules having an even number of carbon atoms. Normal paraffins of intermediate and high molecular weights are present in most crude oils, but only normal paraffins of high molecular weights were detected in the sediments of San Francisco Bay. In the sediments the normal paraffins containing 23-35 carbon atoms per molecule show a predominance of odd-carbon-number molecules. In crude oils the normal paraffins in the same weight range are distributed so that odd-carbon number molecules and even-carbon-number molecules are present in about equal amounts. If the sediments of San Francisco Bay are to yield crude oil, changes probably should take place in the molecular distribution of the normal paraffins already present. The ratio of odd- to even-numbered normal paraffins should be reduced so that the odd- and even-numbered molecules are about equally abundant. Also, normal paraffins of intermediate molecular weights probably should be added to these sediments. The additional normal paraffins may be derived from other organic materials dispersed in the sediments. End_of_Article - Last_Page 271------------

Die Einheit der Naturkrafte in der Thermodynamik

As described in the secondary title, this pamphlet is an attempt to deduce from the kinetic energy of nonelastic atoms, corporeal and ethereal, all known physical forces, chemical, electrical, and mechanical, including gravity. Nothing Boschovichian is assumed; only the kinetic energy of moving atoms of different sizes. It is not easy to follow an argument which provisionally assumes that the atoms are held together to form molecules with regular vibration frequencies capable of propagating through the surrounding swarm of ether-atoms waves of condensation and rarefaction, by means of the reactions and interference of which (when there are two or more molecules) attractions are brought into being; and which then, in terms of this general outlook, gives reasons why the reaction of the ether atoms may be found sufficient to hold the corporeal atoms together. A necessary consequence of the investigation is that gravity is propagated in time, and should be a function of the temperature. The author has tested the latter point by experiment, and finds some evidence in favour of its truth. The source of the chemical elements is found in the different magnitudes of the atoms, with the corresponding differences in their energetic combinations. The temperature of a body is proportional to the mean molecular weight, multiplied by the square of the mean translational velocity of the molecule; divided by the relative number of molecules in unit volume; multiplied by the relative mean path of the molecule. Since, according to the theory elaborated, the kinetic energy of the elementary particles implies attraction, all bodies will be surrounded by a layer of condensed gas and ether particles. In the waves in the ether sheath is found the source of the electrical current. Electrostatic action, on the other hand, depends on chemical actions in the ether sheath. The applications to chemical and electrical phenomena are admittedly crude and imperfectly worked out; but the author claims to have proved the possibility of deducing all the recognised forces of nature from the kinetic energy of non-elastic Lucretian atoms.

Escape of Gases from Planetary Atmospheres

IN the “Astronomical Column” of last week's NATURE, on p. 501, you give an abstract of a paper by Mr. S. R. Cook, of the University of Nebraska, and quote the passage in which he points out that the present writer, when investigating the escape of gases from atmospheres, does not base his argument upon “the determination by the kinetic theory of the relative number of molecules which would have a velocity sufficient to enable them to escape from the earth or planet.”