bluuebunny/crossref_metadata_2025 huggingface dataset:
Tumor necrosis factor‐α induces changes in the phosphorylation, cellular localization, and oligomerization of human hsp27, a stress protein that confers cellular resistance to this cytokine
Authors: Mehlen Patrick , Mehlen Anne , Guillet Dominique , Preville Xavier , Arrigo André‐Patrick
Published: May 2005

The stress protein hsp27 is constitutively expressed in several human cells and shows a rapid phosphorylation following treatment with tumor necrosis factor‐α (TNF‐α). hsp27 usually displays native molecular mass ranging from 100 to 700 kDa. Here, we have analyzed the TNF‐α‐mediated changes in the phosphorylation, cellular localization, and structural organization of hsp27 in HeLa cells. We report that the TNF‐α‐mediated hsp27 phosphorylation is a long‐lasting phenomenon that correlates with the cytostatic effect of this cytokine. Following TNF‐α treatment, the rapid phosphorylation of hsp27 occurred concomitantly with complex changes in the intracellular distribution and structural organization of this protein. This resulted in the quantitative redistribution of hsp27 toward the soluble phase of the cytoplasm. In addition, during the first 2 h of TNF‐α treatment, a transient increase in the native molecular mass of most hsp27 molecules (≤ 700 kDa) occurred. Then, by 4 h of TNF‐α treatment, the native size of this stress protein drastically regressed (< 200 kDa). During this phenomenon, the phosphorylated isoforms of hsp27 remained concentrated in the small or medium‐sized oligomers (< 300 kDa) of this protein. We also analyzed the properties of human hsp27 in transfected murine L929 cell lines that constitutively express this protein. In these cells, TNF‐α induced modifications in the phosphorylation, intracellular distribution, and oligomerization of human hsp27 similar to those observed in HeLa cells. Moreover, the expression of hsp27 in L929 cells was found to correlate with a reduced cytotoxicity of this cytokine. Hence, the complex changes in the phosphorylation, intracellular locale and structural organization of human hsp27 may be related to the protective activity of this protein against the deleterious effects induced by TNF‐α.
T cell receptor‐mediated Ca2+ signaling: Release and influx are independent events linked to different Ca2+ entry pathways in the plasma membrane
Authors: Chakrabarti Rabindranath , Chang Joseph Y. , Erickson Kent L.
Published: May 2005

In this study, we showed that cross‐linking CD3 molecules on the T cell surface resulted in Ca2+ release from the intracellular stores followed by a sustained Ca2+ influx. Inhibition of release with TMB‐8 did not block the influx. However, inhibition of phospholipase C activity suppressed both Ca2+ release and influx. Once activated, the influx pathway remained open in the absence of further hydrolysis of PIP2. Thapsigargin, a microsomal Ca2+ ‐ATPase inhibitor, stimulated Ca2+ entry into the cells by a mechanism other than emptying Ca2+ stores. In addition, Ca2+ entry into the Ca2+ ‐depleted cells was stimulated by low basal level of cytosolic Ca2+, not by the emptying of intracellular Ca2+ stores. Both the Ca2+ release and influx were dependent on high and low concentrations of extracellular Ca2+. At low concentrations, Mn2+ entered the cell through the Ca2+ influx pathway and quenched the sustained phase of fluorescence; whereas, at higher Mn2+ concentration both the transient and the sustained phases of fluorescence were quenched. Moreover, Ca2+ release was inhibited by low concentrations of Ni2+, La3+, and EGTA, while Ca2+ influx was inhibited by high concentrations. Thus, in T cells Ca2+ influx occurs independently of IP3‐dependent Ca2+ release. However, some other PIP2 hydrolysis‐dependent event was involved in prolonged activation of Ca2+ influx. Extracellular Ca2+ influenced Ca2+ release and influx through the action of two plasma membrane Ca2+ entry pathways with different pharmacological and biochemical properties.
Nuclear ultrastructures associated with the RNA synthesis and processing
Authors: Raška Ivan
Published: May 2005

Relatively a little is known about the spatial organization of RNA synthesis, processing, and transport in (mammalian) cell nuclei. This review summarizes results of electron microscopic mapping of RNA synthetic sites and macromolecules involved directly, or indirectly, in the metabolism of RNAs in somatic cell mammalian nuclei. Significance of these results will be discussed in the context of the molecular mechanisms underlying spatial arrangements of RNA metabolism. © 1995 Wiley‐Liss, Inc.
Further characterization of the human cell multiprotein DNA replication complex
Authors: Applegren Nancy , Hickey Robert J. , Kleinschmidt Ann M. , Zhou Qiqi , Coll Jennifer , Wills Philip , Swaby Ramona , Wei Yuetong , Quan Jiang Yuan , Lee Marietta Y. W. T. , Malkas Linda H.
Published: May 2005

Evidence for multiprotein complexes playing a role in DNA replication has been growing over the years. We have previously reported on a replication‐competent multiprotein form of DNA polymerase isolated from human (HeLa) cell extracts. The proteins that were found at that time to co‐purify with the human cell multiprotein form of DNA polymerase included: DNA polymerase α, DNA primase, topoisomerase I, RNase H, PCNA, and a DNA‐dependent ATPase. The multiprotein form of the human cell DNA polymerase was further purified by Q‐Sepharose chromatography followed by glycerol gradient sedimentation and was shown to be fully competent to support origin‐specific and large T‐antigen dependent simian virus 40 (SV40) DNA replication in vitro [Malkas et al. (1990b): Biochemistry 29:6362–6374.]

In this report we describe the further characterization of the human cell replication‐competent multiprotein form of DNA polymerase designated MRC. Several additional DNA replication proteins that co‐purify with the MRC have been identified. These proteins include: DNA polymerase δ, RF‐C, topoisomerase II, DNA ligase I, DNA helicase, and RP‐A. The replication requirements, replication initiation kinetics, and the ability of the MRC to utilize minichromosome structures for DNA synthesis have been determined. We also report on the results of experiments to determine whether nucleotide metabolism enzymes co‐purify with the human cell MRC. We recently proposed a model to represent the MRC that was isolated from murine cells [Wu et al. (1994): J Cell Biochem 54:32–46]. We can now extend this model to include the human cell MRC based on the fractionation, chromatographic and sedimentation behavior of the human cell DNA replication proteins. A full description of the model is discussed. Our experimental results provide further evidence to suggest that DNA synthesis is mediated by a multiprotein complex in mammalian cells. © 1995 Wiley‐Liss, Inc.
Another complete invariant for Steiner triple systems of order 15
Authors: Anglada Olivier , Maurras Jean‐François
Published: May 2005

In this note, the 80 non‐isomorphic triple systems on 15 points are revisited from the viewpoint of the convex hull of the characteristic vectors of their blocks. The main observation is that the numbers, of facets of these 80 polyhedra are all different, thus producing a new proof of the non‐isomorphism of these triple systems. The space dimension of these polyhedra is also discussed. Finally, we observe the large number of facets of some of these polyhedra with few vertices, in relation with the upper bound problem for combinatorial polyhedra. © 2005 Wiley Periodicals, Inc. J Combin Designs.
A model for harvesting of microorganisms using colloidal gas Aphrons
Authors: Save Sanjiv V. , Pangarkar Vishwas G.
Published: May 2005

A theoretical study of the harvesting of microorganisms using Colloidal Gas Aphrons (CGA) is presented. A model for predicting the separation factor of the CGA contactor is proposed which involves parameters that may be estimated through simple experiments.
Isotherm analyses for single component and multi‐component metal sorption onto lignite
Authors: Allen Stephen J. , Brown Pauline A.
Published: May 2005

The adsorption of the three metal ions, copper, cadmium and zinc in single component and multi‐component mixtures in aqueous solutions by lignite is reported. A comparison is made between the single component saturation uptake and the multi‐component uptakes. The isotherms indicate a competitive uptake with copper being preferentially absorbed by the lignite in multi‐component solutions. The isotherms are plotted to obtain the Langmuir constants, the Freundlich constants and the Redlich–Peterson constants. Lignite is shown to possess an affinity for the metal ions which make its use as an adsorbent a possible alternative to the use of more expensive activated carbons.
Removal of phenol from aqueous solutions by continuous RF‐pertraction
Authors: Boyadzhiev Lubomir A. , Alexandrova Sylvia A.
Published: May 2005

Water dephenolation was studied using a multistage Rotating Film Pertractor (RFP). This relatively new liquid membrane technique allows the use of almost water‐insoluble liquids as intermediate organic ‘membranes’. The effects of the main processing parameters such as disc rotation velocity, temperature and phase flowrate, on removal efficiency were studied. A mathematical model describing the process of dephenolation in a counter‐current multistage cascade of n‐RFP contactors was proposed for the prediction of phenol removal.
Synthesis of some new 3‐mercapto‐5‐substituted‐1,2,4‐triazine‐s‐triazoles for evaluation as antimicrobial agents
Authors: El‐Samii Zakaria K. Abd , El‐Feky Said A.
Published: May 2005

The synthesis of several S‐ and N‐substituted derivatives of 5‐[(5,6‐diphenyl‐1,2,4‐triazin‐3‐yl)oxymethyl]‐s‐triazole‐3‐thiol, 2‐[(5,6‐diphenyl‐1,2,4‐triazin‐3‐yl)‐oxymethyl]‐5,6‐dihydrothiazolo‐[3,2‐b]‐s‐briazole, 2‐[(5,6‐diphenyl‐1, 2,4‐triazin‐3‐yl)oxymethyl]‐5H,6,7‐dihydro‐s‐triazolo‐[3,2‐b]‐1,3‐thiazine, 2‐[(5,6‐diphenyl‐1,2,4‐triazin‐3‐yl)oxymethyl]‐5,6‐dihydrothiazolo‐[3,2‐b]‐s‐triazol‐5‐one and 2‐[(5,6‐diphenyl‐1,2,4‐triazin‐3‐yl)oxymethyl]‐6‐phenylthiazolo‐[3,2‐b]‐s‐triazole is reported. All the novel compounds have been screened for antimicrobial activity and one of them showed noteworthy activity.
Chemical and biological oxidation of Pinus pinaster lignin of the production of vanillin
Authors: Mathias Alvaro L. , Lopretti Mary I. , Rodrigues Alirio E.
Published: May 2005

Oxidation of kraft black liquor with 14·39% solids content, obtained by cooking of Pinus pinaster wood, was studied by three different process; chemical oxidation with molecular oxygen at 120–138°C (oxygen partial pressure ≈ 0·15 MPa); biological (enzymatic) oxidation; and combined oxidation (in the sequence: chemical + enzymatic). Lignin degradation was followed by high pressure liquid chromatography (HPLC). Production of low molecular weight compounds, e.g. vanillin, was monitored by gas chromatography (GC). Chemical oxidation produced about 1.5 g of vanillin per dm3 of liquor (0·904 g per 100 g of solids). Biodegradation products had molecular weights near to that of vanillin and mainly around 100 daltons, but vanillin was not detected. In the combined oxidation process, vanillin was consumed with a concomitant reduction of the HPLC peak.
Photocatalytic degradation of organophosphorus pesticides using thin films of TiO2
Authors: Mengyue Zhao , Shifu Chen , Yaowu Tao
Published: May 2005

This paper studies the feasibility of photocatalytic degradation of organophosphorus pesticides using thin films of TiO2. The results show that 0·65 × 10−4mol dn−3 of dichlorvos, monocrotophos, phorate, parathion can be completely photocatalytically degraded into PO within a short time under illumination with a medium pressure mercury lamp of 375 W. The effect of parameters such as he amount of TiO2 attached, initial concentration of organphosphorus pesticides, initial pH, amount of air flow, concentrations of H2O2 and Fe3+ on the photocatalytic degradation are studied. The possible mechanisms of photocatalytic degradation are discussed. It is our assumption that the degradation reactions occur on the surface of TiO2 via primary produced oxidizing species such as the OH radical and O, after 80 h illumination, there is no significant loss of the photocatalytic activity of TiO2.
Gas chromatographic separation of triglycerides according to their degree of unsaturation on glass capillary columns
Authors: Traitler Helmut , Prévǒt And RÉ
Published: May 2005

Triglycerides are separated according to their molecular weight and their degree of unsaturation on glass capillary columns by use of the on‐column injection technique. The columns employed are silylated SE‐30 columns of 4.5, 8, and 10m length with a film thickness of ca. 0.15 μm. The paper gives several examples of chromatograms of natural and hydrogenated triglycerides as well as of mixtures of pure, known triglycerides before and after interesterification.
Continuous and gradient TLC development of 4‐dimethylaminoazobenzene‐4′‐sulfonyl amino acid derivatives
Authors: Gołkiewicz Władysław , Wolski Tadeusz
Published: May 2005

Thin‐layer gradient elution chromatography is a convenient technique for separation of very complicated mixtures; in some cases the gradient technique can be replaced by continuous development. The two techniques are compared in practice by using them to separate a mixture of dabsyl derivatives of amino acids.
Quantitative evaluation of thin‐layer chromatograms. 5. Calculation of reflectance and transmission using Markov chains
Authors: Prošek M. , Medja A. , Kučan E. , Katič M. , Bano M.
Published: May 2005

Changes of reflected and transmitted light in cases where a band lies in different sublayers of a thin‐layer chromatogram are calculated by the use of Markov chains. The problem of a “random walk with absorbing barriers” is described and compared with the problem of transmission and reflectance of light in a layer of sorbent.
The synthesis of isotopically labeled (+)‐2‐aminobicyclo[3.1.0]hexane‐2,6‐carboxylic acid and its 2‐oxa‐ and 2‐thia‐analogs
Authors: Wheeler William J. , O'Bannon Douglas D. , Kennedy Joseph H. , Monn James A. , Tharp‐Taylor Roger W. , Valli Matthew J. , Kuo Fengjiun
Published: May 2005

As part of a program aimed at the design of conformationally constrained analogs of glutamic acid, (+)‐2‐aminobicyclo[3.1.0]hexane‐2,6‐carboxylic acid (1), identified as a highly potent, selective, group II metabotropic glutamate receptor agonist has been synthesized and studied clinically. Heterocyclic analogs of 1 were subsequently synthesized in which the C‐2 methylene has been replaced by an oxygen atom (2) or a sulfur atom (3). C‐14 labeled isotopomers of 1, 2 and 3 have been synthesized to facilitate pre‐clinical ADME studies. A tritium labeled isotopomer of 1 was also synthesized for use in in vitro experiments. A stable labeled isotopomer of rac‐1 was prepared for use as an internal standard for bioanalytical assays. The key step in each of these syntheses was the reaction of chiral ketone 4, 5 or 6 with K14CN/(NH4)2CO3 using the Bucherer–Berg protocol. In the preparation of the stable labeled isotopomer, rac‐4‐[13C2] was prepared in two steps from ethyl bromoacetate‐[UL‐13C2]; subsequent reaction of rac‐4‐[13C2] with K13CN/15NH4Cl/Na2CO3, followed by hydrolysis of the hydantoin yielded rac‐1‐[13C3,15N]. Copyright © 2005 John Wiley & Sons, Ltd.
Characterization of a novel mRNA expressed by neurons in mature brain
Authors: Cohen J. A. , Arai M. , Prak E. Luning , Brooks S. A. , Young L. H. , Prystowsky M. B.
Published: May 2005

In previous studies, differential hybridization screening of an activated murine T‐lymphocyte cDNA library identified an interleukin 2‐responsive mRNA, designated F5, expressed in lymphoid tissues and brain only. We now report characterization of a full‐length clone isolated from an adult mouse brain cDNA library. Neither the nucleic acid nor amino acid sequences demonstrated similarity to reported sequences. On Southern blotting, the protein coding sequence hybridized to genomic DNA from a variety of species. On Northern blotting, F5 mRNA was expressed in adult mouse brain, spinal cord, eye, and dorsal root ganglia but not in peripheral nerve. In situ hybridization studies demonstrated prominent expression by neurons in brain. F5 mRNA expression was undetectable in embryonic rat cerebral hemisphere and low until postnatal day 21. F5 is a novel mRNA selectively expressed by proliferating lymphocytes and mature neurons.
Selective susceptibility of cultured striatal neurons to kainic acid
Authors: Mesco E. R. , Joseph J. A. , Roth G. S.
Published: May 2005

Previous work has shown a selective sensitivity of striatal D2‐receptor‐containing neurons (D2 cells) to kainic acid (KA). In order to see whether this phenomenon exists in cultured cells, which could provide a very accessible model for subsequent mechanistic studies, we examined striatal cultures grown for up to 30 days and labeled with either [3H] spiperone, for D2‐receptors, or with [3H] ‐SCH23390, for D1 receptors. Analysis of the cells was performed with a digital imaging system (RAS). The cultured cells were examined for ligand binding to receptors, cell size, and susceptibility to KA. The D2‐cells showed an increased mortality over D1 ‐receptor‐containing neurons (D1 cells) in the presence of KA, of a magnitude similar to in vivo loss, with larger D2‐cells showing the greatest vulnerability.
Expression of theneuproto‐oncogene by schwann cells during peripheral nerve development and wallerian degeneration
Authors: Cohen J. A. , Yachnis A. T. , Arai M. , Davis J. G. , Scherer S. S.
Published: May 2005

Theneugene, which encodes a putative tyrosine kinase growth factor receptor termed p185neu, was originally identified as a dominant transforming gene in neurogliomas and schwannomas induced by transplacental treatment of rat embryos with ethylnitrosourea. The present studies were undertaken to determine the expression pattern of theneugene in peripheral nerve. Northern blot analysis of total RNA isolated from rat sciatic nerves demonstrated prominentneumRNA expression on postnatal days 1 and 7, with substantially lower expression up to adulthood. Immunohistochemical studies confirmed expression of the p185neuby Schwann cells (SC) in developing sciatic nerve and minimal p185neuimmunoreactivity in adult nerves. However, neu mRNA and p185neuProtein progressively increased following sciatic nerve transection in adult animals. In addition,neumRNA and pl85neuwere found in neonatal rat sciatic nerve SC and several SC‐derived cell lines. In resting SC,neumRNA was expressed at a low level, but was greatly increased by treatment with forskolin and glial growth factor. These studies demonstrate that theneugene and its protein product, p185neu, are expressed by SC both in vivo and in vitro and suggest that p185neuplays a role in the regulation of SC proliferation or differentiation.
Changes in taurine transport evoked by hyperosmolarity in cultured astrocytes
Authors: Sánchez‐Olea R. , Morán J. , Pasantes‐Morales Herminia
Published: May 2005

Cultured astrocytes grown chronically (1–3 days) in medium made hyperosmotic (450 mOsm) with NaCl or sucrose showed an increase in taurine concentration from 294 to 501 nmol/mg protein in NaCl and to 382 nmol/mg protein in sucrose. The effect of hyperosmolarity on taurine uptake and release was examined to investigate whether or not changes in these processes may account for the increase observed in cell taurine content. Hyperosmolarity significantly affected the two components of taurine uptake (i.e., the Na+‐dependent and the diffusional component). The Vmax of the Na+‐dependent, active transport increased 50%, whereas no change was observed in the Km. The diffusion coefficient was markedly decreased by hyperosmolarity, being 2.2 × 10−4 and 6.6 × 10−6 ml/min/mg protein in isosmotic and hyperosmotic conditions, respectively, indicating a blockade of the leak pathway. These changes in the active and passive components of taurine transport were oppossite to those induced by hyposmolarity. The effect of hyperosmolarity increasing cell taurine content was insensitive to cycloheximide and colchicine. The basal efflux of taurine from astrocytes also decreased in cells exposed to hyperosmotic medium, indicating that alterations in both influx and efflux of taurine are involved in the mechanism responsible for the increase in taurine levels induced by hyperosmolarity in astrocytes. © 1992 Wiley‐Liss, Inc.
Resonance Raman spectra of ferri‐hemoglobin fluoride: Three scattering regimes
Authors: Strekas Thomas C. , Packer Andrew J. , Spiro Thomas G.
Published: May 2005

Resonance Raman spectra have been obtained from dilute solutions of ferri‐hemoglobin fluoride, using several Ar+ laser lines, as well as the 6328 Å He  Ne line, for excitation. Several modes (including some with inverse polarization) correspond to vibrations which mix the first two π – π* porphyrin transitions, and their excitation profiles confirm the assignment of the lower of these transitions to a band, at 5280 Å, which is unresolved in the room‐temperature absorption spectrum. Resonance enhancement of porphyrin modes with 6328 Å excitation suggests substantial mixing of the lower π – π* transition with porphyrin‐metal charge transfer transitions, which presumably account for the low energy visible bands. Totally symmetric modes are observed which come into resonance with the intense near‐ultraviolet (Soret) transition. The most intense of these, at 1373 cm−1 accurately obeys the frequency dependence expected for a mode which couples to a single electronic transition.
Étude par spectroscopie Raman en phase vapeur des trois espèces deutérées du formaldéhyde
Authors: Chapput A. , Roussel B. , Fleury G.
Published: May 2005

Les spectres Raman des trois formes deutérées du formaldéhyde ont été étudié en phase vapeur. Nous proposons de nouvelles valeurs des fréquences et une attribution des vibrations fondamentales pour les trois espèces.

L'étude des spectres Raman de rotation nous permet d'accéder aux constantes rotationnelles et de les comparer aux valeurs récentes observées en micro‐ondes.
Low temperature Raman spectra of KHCO3 single crystal
Authors: Lucazeau Guy , Novak Alexandre
Published: May 2005

The KHCO3 single crystal Raman spectra at 300K and 30K have been investigated in the 4000–5 cm−1 range. The far infrared spectrum (300–60 cm−1) of polycrystalline KHCO3 has also been obtained. Fifteen Raman and five infrared active lattice modes from respectively eighteen and fifteen expected ones have been observed. An assignment in terms of factor group symmetry species, rotational, translational and hydrogen bond vibrations is given. Hydrogen bond strength, OH stretching band shape and structure are discussed; combination bands involving mostly OH bending fundamentals are believed to be responsible for the main subband features.
Description of a zero‐dispersion fore‐monochromator for low frequency Raman spectrometry
Authors: Leclercq M. , Wallart F.
Published: May 2005

The addition of a zero‐dispersion double foremonochromator to a spectrograph is described. Raman spectra are obtained in short exposure times. The low stray light level enables the study of very low frequency Raman spectra. This device may be used also with photoelectric spectrometers.
Raman and infrared spectra of SrSeO4 and PbSeO4
Authors: Scheuermann W. , Schutte C. J. H.
Published: May 2005

The Raman spectra of SrSeO4 and PbSeO4, in the form of crystalline powders have been recorded at 295K and 77K and the infrared transmission spectra of these compounds have been recorded from nujol mulls at 295 K. The spectra of these monoclinic compounds were found to be rather complicated, especially in the case of PbSeO4. Evidence was again found, as in a previous publication [1], that the principles of mutual exclusion and inversion doubling are effective in SrSeO4 and PbSeO4. It would seem that interionic coupling is even more pronounced in monoclinic SrSeO4 and PbSeO4 than in orthorhombic BaCrO4 and BaSeO4. An assignment of the most prominent bands was based on comparative data of similar compounds containing the XO4 group.
Raman depolarization ratios and the symmetry of Si(NCO)4 and Ge(NCO)4
Authors: Miller Foil A. , Snider A. Monroe
Published: May 2005

Depolarization ratios, ϱ, have been measured to determine whether or not these molecules are tetrahedral. Totally‐symmetric vibrations of Tb molecules have ϱ0, whereas for all lower symmetries ϱ may be anywhere between 0 and 0.75. For Si(NCO)4 there are two bands with ϱ0.65 and 0.64, showing clearly that it is not tetrahedral. For Ge(NCO)4 the results are ambiguous, for the highest value observed for a polarized line is 0.086. However there is other evidence against Td symmetry for this molecule, especially selection rule behaviour. It is concluded that neither molecule is tetrahedral. The true symmetry is not known.

The complete Raman spectrum has been re‐measured, and the results are given.
Light scattering from polaritons in m‐dinitrobenzene single crystal
Authors: Belikova G. S. , Kulevsky L. A. , Polivanov Yu. N. , Poluektov S. N. , Prokhorov K. A. , Shigorin V. D. , Shipulo G. P.
Published: May 2005

Raman scattering from polaritons in organic biaxial crystal m‐dinitrobenzene has been observed by a photographic method. In order to obtain a greater shift of polaritons the directional dispersion of the incident wave vector has been taken into account, so that the polariton disperison curves over the range from 500 cm−1 to 3500 cm−1 have been observed.
Raman scattering by polaritons under nonstationary conditions. II: Local and wave nonstationary cases
Authors: Marchevskii F. N. , Strizhevskii V. L.
Published: May 2005

The theoretical investigation of stimulated Raman scattering (RS) by polaritons under nonstationary conditions, when local or wave nonstationary properties are separately important has been carried out on the basis of a fluctuation‐dissipation method. General experssions are found which describe the scattered radiation (Stokes and polariton) nonstationary angular distribution at the piezo‐electric crystal scattering layer exit face. In particular, for the local nonstationary case, the detailed analysis of the cases of small stationary gain and of very short and moderately short pump pulses at large stationary gain is carried through. For small stationary gain and also in the case of very short pulses with arbitrary gain, the spontaneous RS regime is realized, the Stokes wave intensity time dependence being on the whole a purely parametric one. The delay effects connected with the finite nature of the scattering polaritons' relaxation time become significant when the coherent component of the polaritons is important. Typical numerical calculations of the scattered radiation pulse shape and peak intensity are carried out for pump pulses of the rectangular and domed form. The most important general manifestations of nonstationary properties of the polariton RS are the apperance of deformation, asymmetry and delay of the scattered radiation pulses relative to the pump pulses; the angular tuning of the pump duration and the scattered radiation frequency tuning; the different character of the influence of local and wave nonstationary properties and so on. These effects are determined by shape and duration of the pump pulses and also by the stationary gain parameter in the material and by the scattering polaritons' relaxation time (for the local nonstationary case) or by the group delay time of the Stokes wave relatively to the pump wave (for the wave nonstationary case).
The shape and width of resonance Raman spectral lines
Authors: Behringer J.
Published: May 2005

Presupposing exponentially decaying states (with phenomenological lifetimes) of the particle system interacting with the radiation field, the shape and width of Raman lines is discussed on a quantum‐mechanical basis for the most important types of excitation: non‐resonance, pre‐resonance, rigorous resonance with a continuum level and with a discrete, non‐degenerate, and isolated level; monochromatic and non‐monochromatic irradiation. Attention is called to peculiar intensity distributions of the secondary radiation obtainable by sufficiently monochromatic excitation in near resonance to an isolated state (resonance fluorescence case) which deviate characteristically from those customary in traditional fluorescence and scattering spectra.
Raman intensity and conjugation. IV‐determination of the conjugation between a phenyl ring and a carbonyl group by Raman intensity
Authors: Schmid E. D. , Schlenker P. , Brand R. R. M.
Published: May 2005

The Raman intensities SCO and S8a,b of the CO‐stretching vibration and the 8a, b‐ring vibrations of some compounds of type C6H5‐CO‐X (X = NHNH2, NH2, OC2H5, OCH3, CH3, CH2Cl, H, CL, CF3, CN) have been measured using the excitation lines of an argon ion and a krypton ion laser. The intensities in the two series are linearly related and the (RI)1/2 values correlate both with Hammett substituent parameters and with the extinction coefficients of the longest wavelength u.v. absorption band. The results are interpreted by showing that the intensities here are almost independent of the resonance Raman effect and thus reflect the conjugation effect. Relative Raman intensity values can thus be used to measure the conjugation between a phenyl ring and various carbonyl groups.
Raman scattering investigation of the monoclinic to orthorhombic phase transition in TbP5O14
Authors: Fox David L. , Scott J. F. , Bridenbaugh P. M. , Pierce J. W.
Published: May 2005

The low‐frequency Raman spectrum (6–50 cm−1) of TbP5O14 over the temperature range 300–620 K is reported and the behavior of the soft mode observed, is discussed.
The dependence of Raman intensity on the scattering frequency
Authors: Temperini Marcia L. A. , Sala O. , Bernstein H. J.
Published: May 2005

Aqueous solutions of (NH4)2MoS4 have been investigated with Ar+ laser excitation, at frequencies which span the visible absorption spectrum. Enhanced values of the anti‐Stokes/Stokes intensity ratios for the fundamental ν1 and overtone 2ν1 show that the Nafie et al. theory accounts satisfactorily for these observed ratios.
Solvent effect on the Raman parameters of the ν (BrBr) band
Authors: Maes Guido , Zeegers‐Huyskens ThéRèse
Published: May 2005

The νBrBr Raman band of bromine dissolved in several organic solvents has been studied. The frequency shift, band width, depolarization ratio and absolute intensity of the band have been determined and discussed in terms of the polarity of the solvent or as a function of specific charge transfer interactions.
Experiments on Raman versus primary light scattering fluxes from pressed discs
Authors: Klosowski J. , Steger E.
Published: May 2005

Relative fluxes of transmitted and backscattered Raman (inelastic) and also Rayleigh plus macroscopically (elastic) scattered radiation from powdered samples pressed to discs have been measured as a function of the thickness of the discs. Specular reflection is the biggest source of error and must be avoided in such measurements. The resulting curves are in qualitative accordance with calculations by other authors.
Aromatic bromination catalysis on zeolites. I—Raman spectra of activated adsorbed bromine
Authors: Cooney Ralph P. , Tsai Peter
Published: May 2005

Laser Raman spectra of Br2 adsorbed on zeolites X, Y and A reveal features characteristic of physisorbed Br2 and of Br2 on cation oxide sites. Specifically, Br2 on zeolites X adsorbs on sites III (ν(BrBr), 318–280 cm−1) and on sites II (ν(BrBr), 280–240 cm−1). The data indicate that the cations in sites II are more effectively shielded by the oxide framework than those in sites III. The greater participation of the oxide framework in the adsorption at sites II is also reflected in the detection of the adsorbate–adsorbent frequency, ν(O ⃛Br) at ∼ 160 cm−1. The appearance of this line is indicative of significant donor (oxide)–acceptor (bromine) electron‐transfer interaction. The spectra of the adsorption complex NaY + Br2 confirm the assignments for MX + Br2 as NaY has no cations in sites III and fewer cations in sites II than NaX, with the result that only Br2 on sites II (271 cm−1, NaY; 270 cm−1, NaX) and physisorbed Br2 is detected. For NaA, no ν(O ⃛Br) is detected, which is consistent with the previously reported absence of charge‐transfer interactions between the oxide framework and Br2.
Raman study of the influence of conformational structure on the ν1 and ν13 vibrations of the benzene ring in polystyrene and its model compounds
Authors: Jasse B. , Chao R. S. , Koenig J. L.
Published: May 2005

The influence of the chain conformation on the ν1 and ν13 normal modes of the benzene ring in atactic and isotactic polystyrene and their model compounds has been investigated by Raman spectroscopy. The ν1 mode which appears in the 750–800 cm−1 region is influenced as much by the local conformation of the alkyl chain as by the length of the considered conformational structure along the chain. The ν13 mode which appears in the 1195–1215 cm−1 region is only influenced by the local conformation and is insensitive to the length of the alkyl chain.
Infrared and Raman spectral studies of meso‐ 1, 2, 3, 4‐tetrabromobutane and meso‐ 1, 2, 3, 4 ‐ tetrachlorobutane
Authors: Crowder G. A.
Published: May 2005

Infrared and Raman spectra were obtained for meso ‐ 1, 2, 3, 4‐tetrabromobutane and meso‐1, 2, 3, 4‐tetrachlorobutane. The spectra of both compounds were interpreted in terms of a centrosymmetrical conformation that has all carbons and primary halogens coplanar, with the secondary halogens being on opposite sides of that plane. Additional conformations are present in solution. Vibrational assignments are proposed, based on approximate normal coordinate calculations.
A Raman spectroscopic study of complexes of thiocyanate at the silver electrode surface
Authors: Gold Harvey S. , Buck Richard P.
Published: May 2005

Raman spectra of thiocyanate at the surface of a silver electrode and in a series of aqueous test solutions were compared. The results indicate that spectral variations can be correlated with changes in bonding stoichiometry at the electrode surface as a function of potential.
Analyse Vibrationnelle et Structurale en Série Aliphatique Saturée. II—Spectres de Vibration de l'Acide Succinique et de ses Sels Alcalins en Solution Aqueuse
Authors: Maury Luc , Bardet Lucette
Published: May 2005

Raman and infrared spectra of succinic acid (CH2COOH)2, (CH2COOD)2 and its alkaline salts KH(CH2COO)2, KD(CH2COO)2 and K2(CH2COO)2 in aqueous solution have been investigated from 3500 to 400 cm−1; an assignment of the fundamental vibrations is proposed. The analysis of the polarization ratio leads us to conclude that the neutral salt belongs to point group Cs. The acid salt and the acid itself belong to point group C1 and do not exhibit intramolecular bonding.
Spectra and structure of silicon containing compounds. 13—infrared and Raman spectra of 1,1‐dimethyl‐1‐silacyclopentane
Authors: Durig J. R. , Johnson‐Streusand M.
Published: May 2005

The infrared spectra of 1,1‐dimethyl‐1‐silacyclopentane in the vapor and solid phases have been recorded from 4000 to 20 cm−1. The Raman spectra (3500‐0 cm−1) of all phases have been measured and depolarization data have been obtained for both the gaseous and liquid phases. An assignment for the 57 normal modes is presented. The vibrational data are consistent with a twisted ring with molecular symmetry C2. The two low frequency bending modes were observed at 260 cm−1 (radial motion) and 63 cm−1 (puckering motion) but distinct ‘hot band’ transitions were not observed. Thus, the potential functions and the dynamics of the low frequency ring‐bending motions could not be calculated.
On the fermi resonance observed in molecules undergoing a large amplitude vibration
Authors: Konarski J. , Molski A. , Kreglewski M.
Published: May 2005

By using a simple model of a molecule undergoing a large amplitude vibration (LAV), it is shown that the Fermi resonance observed in such a class of molecules exhibits a temperature dependence.
Raman difference spectroscopy as a probe of biological molecules
Authors: Rousseau D. L.
Published: May 2005

The application of Raman difference spectroscopy to biological molecules, briefly reported previously,1 is described here in detail. With Raman difference instrumentation frequency differences of less than 0.1 cm−1 in 10 cm−1 wide lines may be reliably detected. The limitation in the ultimate sensitivity for the detection of small differences lies in the signal to noise ratio, the presence of multiple lines and line shape differences. Spectrometer resetability, spectral resolution and step increment size impose no severe restrictions on obtaining small frequency differences. Differences in Raman excitation profiles between two samples may also be examined with this technique, and by making a simple adaptation Raman polarization difference spectra may be studied as well.
Raman scattering from excitons and from photoexcited electrons and holes
Authors: Scott J. F. , Toms D. J.
Published: May 2005

Raman spectroscopy has been performed on a variety of ‘hot’ photoexcited electron systems. In p‐type ZnTe large densities of photoexcited electrons can be produced in a steady‐state fashion with only milliwatts of laser excitation well below the bandgap. Spin‐flip Raman scattering from these photoexcited minority carriers is easily detected and is in fact often more intense than the majority carrier transitions. In addition, ‘hot’ hole transitions are observed in the hydrogenic As acceptor series in ZnTe; transitions originating on the 2P5/2 or vibronic 1S3/2 + LO states are observed under similar conditions. These transitions give electron/hole temperatures at several hundred degrees at lattice temperatures of 1.6 K. Raman scattering from photoexcited excitions is observed and analyzed in p‐InSb.
Characteristics of a generalized susceptibility for the analysis of lineshapes of Raman spectra
Authors: Takagi Yasunari , Shigenari Takeshi
Published: May 2005

The characteristics of the generalized Van Vleck‐Weisskopf–Fröhlich type susceptibility (GVWF) are discussed. It is shown that the GVWF can represent both an oscillator type and a relaxational (Debye) type of phonon mode, usually adopted in the analysis of Raman spectra of soft modes in structural phase transitions. It is also shown that a susceptibility for a Ising‐spin system in a transverse field has a close resemblance to the GVWF.
Free radical studies by resonance Raman spectroscopy: Chemically and photochemically generated 1,4‐diaminobenzene radical cation
Authors: Ernstbrunner E. E. , Girling R. B. , Grossman W. E. L. , Mayer E. , Williams K. P. J. , Hester R. E.
Published: May 2005

The free radical cation of 1,4‐diaminobenzene (p‐phenylenediamine, PPD+.) has been generated in aqueous solution, wherein it is short‐lived, by oxidation of the parent compound with bromine. The same PPD+. radical has also been produced by UV photolysis of the parent at 77 K in an ethanolic glassy matrix. Resonance Raman spectra of the radical and its parent are reported and analysed in detail with the aid of normal coordinate and molecular orbital calculations. Evidence is presented for (PPD+.)2 dimer formation in aqueous solution at room temperature.
Free radical studies by resonance Raman spectroscopy: Photochemically generated para‐substituted aniline cation radicals
Authors: Williams K. P. J. , Hester R. E.
Published: May 2005

The free radical cations of a series of para‐ substituted anilines have been formed by UV photolysis of the neutral parent compounds trapped in clear glassy ethanol matrices at 77 K. The radicals all have intense visible absorption bands which facilitate excitation of their resonance Raman spectra. These Raman spectra have been assigned and interpreted in terms of structure changes from the corresponding parents. The changes are shown to correlate well with the appropriate Hammett σp function values for the para‐substituents.
Raman microprobe characterization of urea: n‐paraffin inclusion compounds
Authors: Blaha J. J. , Rosasco G. J.
Published: May 2005

Urea:n‐paraffin inclusion compounds have been formed through sonification of urea with pure paraffin liquids. Raman microprobe spectra of individual microcrystals (5–50 μm in size) of these materials are interpreted in terms of a non‐planar conformation for the included paraffins. A series of trans and gauche bonds is shown to yield a conformation of the included alkane that preserves the full symmetry of the hexagonal urea host. The urea host lattice spectrum thereby shows additional sharp bands consonant with a more highly ordered host lattice. These observations are contrasted to the case of the trans‐planar conformation normally encountered and verified in this work for urea:n‐paraffin inclusion compounds prepared from solution.
Laser Raman spectra of potassium sulphamate single crystal
Authors: Raj A. Sundara , Muthusubramanian P. , Krishnamurthy N.
Published: May 2005

Room temperature polarized Raman spectra of potassium sulphamate single crystals have been investigated in the region 30–3400 cm−1 using laser excitation. All lattice modes, excepting two, have been observed. The reassignment of the internal modes of (NH2SO3)− ion has been verified by computing the potential energy distribution. The observed correlation field splitting in KNH2SO3 crystal is very small, of the order of 5–10 cm−1.
Raman and infrared spectra of CH3O(CH2)nOCH3 (n = 3–5) as model compounds of polyethers
Authors: Matsuura Hiroatsu , Murata Hiromu
Published: May 2005

Raman and infrared spectra have been measured for CH3O(CH2)n OCH3 (n = 3–5), as model compounds of polyethers [O(CH2)n]m, in the liquid and crystalline solid states. The spectra were analysed on the basis of a normal coordinate treatment. The CH2O stretching vibration is sensitive to the conformation about the CC bond next to the CO bond. The molecular conformations of the model compounds in the crystalline solid state are trans‐gauche‐gauche‐trans for n = 3 and all‐trans for n = 4 and 5. These conformations coincide with the chain conformations of the polymers in the most stable crystal modification. For the model compounds in the liquid state, the gauche conformation about the CC bond next to the CO bond is more stable than the trans conformation.
Fermi resonance of tyrosine and related compounds. Analysis of the Raman doublet
Authors: McHale Jeanne L.
Published: May 2005

The model compound data of Siamwiza et al. on the Fermi resonance doublet of various para‐substituted benzenes is analysed theoretically to obtain the uncoupled frequencies and intensities of the ring breathing mode and the first overtone of the out‐of‐plane bending mode. The possibility of obtaining accurate information on the state of ionization of tyrosine hydroxyl groups in proteins from an analysis of the experimentally observed peak frequencies and intensities is discussed.
Structure of aqueous solutions: Fourier transformation and band component analysis in magnesium nitrate solutions
Authors: James David W. , Carrick Malcolm T. , Frost Ray L.
Published: May 2005

The polarized Raman spectra of aqueous solutions of Mg(NO3)2 have been obtained over the concentration range 0.05 m to 4.0 m. The Fourier transform of the isotropic band profile of the v1 symmetrical stretching frequency of the nitrate ion gives evidence of more than one component. A technique is described to obtain information on the number of component bands and their relative intensities. The bands were subject to component analysis and the results are discussed in terms of three main solution species. The association constant for the formation of solvent separated ion pairs is calculated to be ∼ 2 dm3 mol−1. Evidence is presented for the presence of contact ion pairs at all concentrations above 2 M.
Raman spectral characterization of pure and fluorine‐doped vitreous silica material
Authors: Dumas P. , Corset J. , Levy Y. , Neuman V.
Published: May 2005

Fluorine doped silica samples have been investigated by Raman spectroscopy. The results obtained allow us to propose a model for dopant incorporation in the silica network, involving the formation of SiO3F tetrahedron. A relationship between the intensity of the ν(Si‐F) stretching vibration band and the refractive index is presented.
Coherent anti‐stokes raman spectra of isoalloxazines
Authors: Müller F. , Vervoort J. , Lee J. , Horowitz M. , Carreira L. A.
Published: May 2005

Coherent anti‐Stokes Raman spectra (1700–1100 cm−1) of 7,8‐dimethyl‐10‐tetraacetylisoalloxazine (tetracetylriboflavin) in chloroform and several other solvents of higher polarity and proton availability are reported. Solvent polarity has no influence on either the intensities or frequencies of the Raman modes, whereas the influence of protic solvents is more marked. As well as altering the effective mass of the particular atoms in the isoalloxazine involved, hydrogen bonding is known to change the bond hybridization throughout the entire ring system. A similarly mild electronic perturbation can be produced by changing the methyl substitution on the benzene subnucleus of the isoalloxazine, and this is shown to produce significant changes in the Raman spectrum. Isotopic substitution with 13C and 15N is used to mimic the effective mass changes that would occur on hydrogen bonding. For the model compounds in chloroform, the effect of isotopic substitution on some modes is different from that reported for the same substitution in riboflavin bound to riboflavin binding protein. Frequencies of the prominent bands in all spectra were determined by lineshape analysis. On the basis of these results a tentative interpretation is made of the changes that occur in the Raman spectra of flavins when they bind to flavoproteins.
Étude du Polypropylène Isotactique Étiré Uniaxialement par Effet Raman: Nouveaux Résultats
Authors: Cambon L. D. , Vinh Luu Dang
Published: May 2005

On étudie des échantillons de polypropylène isotactique, étirés uniaxialement à chaud, par effet Raman polarisé. En comparant les divers spectres obtenus, on met en évidence un classement des raies observées selon trois groupes. Reliant ce travail à une étude théorique des tenseurs de polarisabilités dérivées, on définit la hiérarchisation des éléments du tenseur pour chacun de ces groupes. A partir de ces nouveaux résultats, on complète les attributions du polypropylène isotactique faites antérieurement.
Application of the rotational diffusion model to the CARS spectra of high‐temperature, high‐pressure water vapour
Authors: Greenhalgh Douglas A. , Hall Robert J. , Porter Fiona M. , England William A.
Published: May 2005

CARS spectra of water vapour at elevated pressures (1–16 bar) and temperatures (300–800 K) have been investigated experimentally and theoretically. A theoretical model of the CARS spectrum of water vapour based on Gordon's rotational diffusion model was tested. The model was adapted to include the effects of vibrational relaxation and dephasing processes. Good agreement was found between experiment and theory for all conditions investigated. Rotational inelastic collisions are dominant and contribute approximately 65% to the overall individual molecular linewidths. As part of the data analysis a new measurement of dσ/dω (H2O)=1.10 × 10−34 ± 20% m2 sr−1 has been made.