bluuebunny/crossref_metadata_2025 huggingface dataset:
Deactivation, coating and performance of nickel capillary columns for GLC
Authors: Rohwer E. R. , Pretorius V. , Hulse G. A.
Published: May 2005

Electroformed nickel tubing was deactivated by chemical vapor deposition of silicon from silane gas and subsequent treatment with cyclooctamethyltetrasiloxane (D4). Standard activity tests performed on the uncoated tube and also on columns coated with crosslinked and uncrosslinked, nonpolar stationary phase, show that good quality flexible columns can be prepared from nickel tubing. The inner surface of the silicon coated tube was characterized by Auger depth profile analysis.
Advances in the liquid chromatography of hop bitter compounds
Authors: Verzele M. , Steenbeke G. , Dewaele C. , Verhagen L. C. , Strating J.
Published: May 2005

High efficiency liquid chromatography (LC) on both coupled conventional columns and long micro‐LC columns, both with diode array detection, has revealed the presence of some hitherto unknown compounds in hop extracts. Proof is advanced that ethanol extracts of hops contain iso‐alpha acids.

The elution order of the cis‐trans pairs of the iso‐alpha acids, and the separation of the alpha acids from the deoxyalpha acids, is reversed by switching from methanol to acetonitrile in the reversed phase solvent system.

An LC solvent system giving higher resolution (higher selectivity factor) of the iso‐alpha acid cis and trans stereoisomers is obtained by adding magnesium salts to the eluent.
A water trap for static cryo‐headspace gas chromatography
Authors: Kolb Bruno , Zwick Gerhard , Auer Maria
Published: May 2005

The headspace gas in static headspace gas chromatography contains mostly saturated water vapor. In the case of the cryofocusing enrichment technique this may cause baseline distortion in the early part of the chromatogram or may even lead to ice‐plugging of the capillary column. A water‐trap is described in which the water vapor is removed from the headspace gas before entering the cryo‐trap. The water trap is packed with lithium chloride on a porous support and is regenerated after each analysis by heating under backflush conditions. It therefore can be used for automatic operation. Data are given for the precision and accuracy, and some practical examples, for environmental and flavor analysis are shown.
Dimethylbenzothiophenes and methyldibenzothiophenes in crude oils from different sources
Authors: Andersson Jan T. , Sielex Klaus
Published: May 2005

A method is presented for the identification and quantification of C2‐substituted benzothiophenes in crude oil. The method will enable analysis of the pattern of these compounds, for example as a basis for differentiating crude oils from one another (fingerprinting) and for investigation of their suitability as indicators of oil maturity. Here results are reported for five crudes from Iraq, Venezuela, Saudi Arabia, the former Soviet Union, and the North Sea. The aromatic fraction of the crudes was oxidized and the dioxides of the heterocycles separated according to the number of carbon atoms in the side chains. The final separation was by capillary GC with atomic emission or flame ionization detection. A fluorinated analog was synthesized and used as internal standard. The concentrations of 2,3‐, 2,4‐, 2,7‐, and 3,7‐dimethylbenzothiophene ranged between 11 and 272 ppm. Three other dimethylated benzothiophenes present in lower amounts were also identified.
Supramolecular selective transport of Ca2+/Na+ by dicarboxylic ligands across bulk liquid membranes
Authors: Biancardi Alberto , Marchelli Rosangela , Dossena Arnaldo
Published: May 2005

Bulk liquid membrane transport of Ca2+ and Na+ ions was performed with dicarboxylic type ligands containing (S)‐phenylalanine (Phe‐2‐O) and (S)‐benzyltyrosine (Bz‐Tyr‐2‐O) in pH gradients. With Bz‐Tyr‐2‐O, calcium was generally favoured at every pH, the transport rate strongly depending upon the ligand concentration. At pH 8, a reversal of selectivity (Na+/Ca2+) was observed for the first time at low ligand concentration, thus suggesting that a supramolecular‐type of transport occurs as a consequence of the different assemblages formed by the ligand according to pH and concentration. This is the first case of M2+/M+ selectivity induced by the carrier concentration.
Platelet‐derived growth factor and regulation of schwann cell proliferation in vivo
Authors: Hardy M. , Reddy U. R. , Pleasure D.
Published: May 2005

To examine the role of platelet‐derived growth factor (PDGF) in the in vivo regulation of Schwann cell proliferation, steady‐state levels of mRNAs encoding PDGF A and B chains, and PDGF α and β receptors were measured in immature and adult rat sciatic nerves and in cultured rat Schwann cells. PDGF B chain and PDGF β receptor mRNAs are present in immature rat sciatic nerves and to a lesser extent in adult rat nerves. Short‐term cultures of neonatal rat Schwann cells express PDGF β receptor mRNA, but not PDGF B chain mRNA, and are stimulated to synthesize DNA by addition of PDGF BB to the medium. These data indicate that PDGF BB is a developmenttally regulated paracrine growth factor for rat Schwann cells. Very long‐term cultures of rat Schwann cells, which have lost normal dependence on exogenous growth factors, express PDGF B chain mRNA as well as mRNAs encoding the PDGF α and β receptors, suggesting that, under these circumstances, PDGF BB also acts as an autocrine growth factor. PDGF A chain mRNA is present in both immature and adult rat sciatic nerves and is expressed by primary and secondary cultures of rat Schwann cells as well. However, because the abundance of PDGF α receptor mRNA is very low in rat Schwann cells, PDGF AA is not likely to be a significant autocrine growth factor for rat Schwann cells.
Spatial memory in aged rats: Population heterogeneity and effect of levocarnitine acetyl
Authors: Ghirardi O. , Giuliani A. , Caprioli A. , Ramacci M. T. , Angelucci L.
Published: May 2005

The existence in a population of aging rats of classes that display a different performance in the Morris water‐maze test was investigated by cluster analysis procedure. These classes identified at 18 months of age showed a different response to levocarnitinc acetyl and had a different behavioral profile when tested at 25 months of age. These findings demonstrate the need for an alternative interpretation of variability in animal populations as measured by the standard statistical analyses. The data analysis strategy we propose here will allow for the use of variability as a useful source of information.
Immunohistochemical localization of beta‐amyloid precursor protein sequences in Alzheimer and normal brain tissue by light and electron microscopy
Authors: McGeer P. L. , Akiyama H. , Kawamata T. , Yamada T. , Walker D. G. , Ishii T.
Published: May 2005

Immunohistochemical staining with antibodies directed against four segments of the amyloid precursor protein (APP) was studied by light and electron microscopy in normal and Alzheimer (AD) brain tissue. The segments according to the Kang et al. sequence were:18–38 (T97); 527–540 (R36); 597–620 (1–24 of β‐amyloid protein [BAP], R17); and 681–695 (R37) (Kang et al. [1987]: Nature 325:733–736). The antibodies recognized full length APP in Western blots of extracts of APP transfected cells. They stained cytoplasmic granules in some pyramidal neurons in normal appearing tissue from control and AD cases. In AD affected tissue, the antibodies to amino terminal sections of APP stained tangled neurons and neuropil threads, and intensely stained dystrophic neurites in senile plaques. By electron microscopy, this staining was localized to abnormal filaments. The antibody to the carboxy terminal segment failed to stain neurofibrillary tangles or neuropil threads; it did stain some neurites with globular swellings. It also stained globular and elongated deposits in senile plaque areas. The antibody against the BAP intensely stained extracellular material in senile plaques and diffuse deposits. By electron microscopy, the antibodies all stained intramicroglial deposits. Some of the extracellular and intracellular BAP‐positive deposits were fibrillary. Communication between intramicroglial and extracellular fibrils was detected in plaque areas. These data suggest the following sequence of events. APP is normally concentrated in intraneuronal granules. In AD, it accumulates in damaged neuronal fibers. The amino terminal portion binds to abnormal neurofilaments. Major fragments of APP are phago‐cytosed and processed by microglia with the BAP portion being preserved. The preserved BAP is then extruded and accumulates in extracellular tissue.
Cytoskeletal elements regulate the distribution of nerve growth factor receptors in PC12 cells
Authors: Spoerri P. E. , Roisen F. J.
Published: May 2005

Nerve growth factor receptor (NGFR)‐like immunoreactivity (IR) was studied in PC12 cells treated for 96 hr with NGF (40 ng/ml), using immunogold labeling and electron microscopic morphomctric analysis. The cells were exposed to the anti‐NGFR antibody 192‐IgG, followed by immunoglobulin (IgG) conjugated with colloidal gold. PC12 cells exhibited occasional gold label (positive NGFR‐IR) on all surfaces. Cells treated with colcemid (0.05 μg/ml) or cytochalasin D (2 μg/ml), which limit microtubule (MT) and microfilament (MF) formation, respectively, displayed an increased NGFR‐IR in terms of gold labeling. NGFR‐IR was also seen on taxol (0.85 μg/ml)‐exposed cells, an agent that promotes MT assembly. Cells treated simultaneously with cytochalasin D and taxol had a dramatically augmented NGFR‐IR on their surfaces, which exceeded levels obtained with either agent alone. Prominent NGFR‐IR was localized frequently in coated endocytotic vesicles, in smooth endoplasmic reticulum, and in secondary multivesicular lysosomes, in both treated and untreated cells. The results suggest that a large number of NGFRs (positive NGFR‐IR) in PC12 cells are cryptic and not available for ligand binding. Changes in cytoskeletal organization that may affect mobility of integral membrane proteins can modulate the distribution of NGFR‐IR on neuronal surfaces.
Differential coupling of opioid binding sites to guanosine triphosphate binding regulatory proteins in subcellular fractions of rat brain
Authors: Szücs M. , Coscia C. J.
Published: May 2005

In this study, we present evidence for the occurrence of μ, δ, and κ opioid binding sites in synaptic plasma membranes (SPM) and microsomes of rat brain. Binding to all three opioid classes was inhibited by 5′‐guanylylimidodiphosphate (Gpp[NH]p) in SPM, while microsomal sites proved to be insensitive to this GTP analog. Sensitivity was restored upon solubili‐zation of microsomes with digitonin, suggesting that opioid receptors are physically separated from G proteins in this fraction. Modulation of microsomal binding by Na+ and Mn++ was greater than that of SPM. Pertussis toxin‐catalyzed adenosine diphosphate (ADP) ribosylation revealed the presence of G proteins with α‐subunit molecular weights of 40 kDa in both subcellular fractions. Basal low Km GTPase activity in SPM was greater than in microsomes. Etorphine elicited a concentration‐dependent stimulation of guanosine triphosphatase (GTPase) activity in SPMs but not in microsomes, indicating functional coupling of opioid receptors to G protein in the former and an uncoupling in the latter. Microsomes from 3‐day‐old rat brain contained more μ opioid sites and they were more sensitive to Gpp(NH)p inhibition than those in adults. These results are consistent with the hypothesis that opioid binding sites in adult microsomes are internalized and G protein uncoupled, while those in neonates are newly synthesized, coupled receptors.
Neuronal origins of K+‐evoked amino acid release from cerebellar cultures
Authors: Simmons M. L. , Dutton G. R.
Published: May 2005

Neuronal cultures from rat cerebellum consisting of approximately 90% glutamatergic granule neurons, 5–7% GABAergic inhibitory interneurons, and 3–5% glial cells, were treated for four days with 50 μM kainic acid (KA) to determine the cellular origin of released endogenous neuroactive substances. KA, known to be selectively toxic to GABAergic neurons, caused an estimated 80% decrease in glutamic acid decarboxylase (GAD) immunofluorescence. Furthermore, K+‐stimulated release of GABA decreased to 20% of control values, and did not return to control levels in cultures "recovered" two days in KA‐free media, suggesting the loss of inhibitory interneurons. Similarly, adenosine and taurine showed decreased K+‐stimulated release, which was unrecoverable when KA was removed from the medium. K+ stimulated release of glutamate and aspartate also decreased by 50% and 70%, respectively, after chronic KA treatment. In contrast, however, this release returned to control levels in recovered cultures. All decreases in K +‐stimulated release were Prevented concurrent treatment with KA and the KA antagonist 6‐cyano‐6‐nitroquinoxaline‐2,3‐dione (CNQX), indicating that a receptor‐mediated mechanism was involved. We conclude that, in these cultures, most of the K+‐stimulated release of adenosine and taurine originates from the GABAergic interneurons, the basket and stellate cells, which are selectively killed by the KA treatment. The data also strongly suggest that glutamate and aspartate, the levels of which recover after KA treatment, originate mainly from the granule neurons.
Dystrophin immunoreactivity in normal and duchenne human fetal neurons in culture
Authors: Torelli S. , Sogos V. , Ennas M. G. , Muntoni F. , Clerk A. , Strong P. N. , Gremo F.
Published: May 2005

Dystrophin, the protein product defective in Duchenne muscular dystrophy (DMD), is present in all types of muscle and in the brain. The function of the protein is unknown and its role in the brain is unclear, although 30% of DMD patients show nonprogressive mental retardation. We have therefore studied the localisation of dystrophin in cultures of normal and DMD human fetal neurons using antibodies raised to different regions of the protein. Dystrophin immunoreactivity was demonstrated in the soma and axon hillock of normal neurons and appeared to be associated with the inner part of the cell membrane, although some intracellular staining was also observed. Positive dystrophin staining was present only in cells with fully developed neuronal features, although not all the neurons were positive. Glial cells were always negative for the antigen. Immunostaining with antibodies to the brain spectrins indicate that the dystrophin antibodies did not cross‐react with these proteins. The possibility of cross‐reactivity with other proteins is discussed.

Studies of cells cultured from a DMD fetus also showed specific dystrophin immunostaining in neurons, although the muscle was generally negative for dystrophin. However, the localisation of dystrophin immunostaining and that of the brain spectrins and neurofilaments appeared abnormal, as did the overall morphology of the cells. This suggests that dystrophin may play a role during brain development and dystrophin deficiency results in abnormal neuronal features. This would be consistent with the nonprogressive nature of the mental retardation observed in DMD patients. © 1992 Wiley‐Liss, Inc.
Alterations in slow transport kinetics induced by estramustine phosphate, an agent binding to microtubule‐associated proteins
Authors: Sahenk Zarife , Mendell J. R.
Published: May 2005

Estramustine phosphate (EP) disassembles microtubules by binding to microtubule‐associated proteins (MAPs) rather than tubulin. In this study, EP‐induced alterations of MAP integrity caused a unique form of axonal atrophy in rats. Initially, EP‐induced axonal atrophy occurred in both proximal and distal axons of the sciatic nerve, characterized by an increase in neurofilament packing density, associated with a decrease in axonal area. In chronic exposure, distal axonal atrophy was associated with decreased numbers of microtubules, while the neurofilament number remained unaltered for the myelin spiral length. Continued exposure caused enlargement of proximal axons associated with an increase in neurofilament content. Correlative slow transport studies done at two different times, 7 and 14 days after [35S] methionine injection showed that EP retards the transport of cytoskeletal proteins migrating with both components of slow transport (SCa and SCb). However, there was a differential effect on SCb which showed progressive slowing along the nerve while the rate of SCa stayed relatively constant.

In this model, the early occurring distal axonal atrophy can best be explained by reduced cytoskeletal components, particularly those traveling in SCb. Later in the course of intoxication, a relatively constant rate of SCa permitted continuous transport of neurofilament triplets, accounting for unaltered numbers of neurofilaments in distal axons with increased packing density. This model of axonal atrophy is unique because spacing of neurofilaments, not numbers determined axon size. Furthermore, EP‐induced dissociation of the SCa and SCb kinetics suggests that MAPs play a role in the orderly, cohesive migration of slow transport components, essential for the normal organization of cytoskeleton. © 1992 Wiley‐Liss, Inc.
Basic fibroblast growth factor expression is required for clonogenic growth of human glioma cells
Authors: Morrison Richard S. , Giordano S. , Yamaguchi F. , Hendrickson S. , Berger M. S. , Palczewski Krzysztof
Published: May 2005

Basic fibroblast growth factor (bFGF) is a heparinbinding protein, expressing potent mitogenic and angiogenic properties. Elevated levels of bFGF have been identified in human gliomas and glioma cell lines, suggesting that bFGF expression is involved in the aberrant growth patterns associated with these tumors. In the present study, the influence of bFGF on additional parameters of glioma cell malignancy was evaluated utilizing three distinct methods to suppress bFGF expression or activity including antisense oligonucleotide primers, a neutralizing monoclonal antibody or an inhibitor of the agonist action of bFGF: (1) The addition of 30 μM bFGF‐specific antisense oligonucleotide primer to the human glioma cell line SNB‐19 resulted in a 55% inhibition in colony formation in soft agar. This effect was dose‐dependent and specific, as sense strand primer was ineffective in suppressing growth. In addition to exhibiting fewer colonies, antisense treatment significantly altered colony morphology. (2) SNB‐19 cell growth in culture was suppressed in the presence of a neutralizing bFGF‐specific monoclonal antibody. (3) Inositolhexakisphosphate, a newly identified antagonist of FGF binding and activity, suppressed SNB‐19 cell growth in soft agar culture. These results demonstrate that bFGF may regulate glioma growth and progression independent of its role in tumor angiogenesis and that bFGF release or secretion may be required for these actions. © 1993 Wiley‐Liss, Inc.
Protein kinase C activity modulates myelin gene expression in enriched oligodendrocytes
Authors: Asotra Kamlesh , MacKlin W. B.
Published: May 2005

Protein kinase C (PKC) and its potential role in myelin gene expression were investigated in primary cultured rat oligodendrocytes. The major myelin genes were expressed in a developmentally coordinated manner in cultured oligodendrocytes. PKC activity in these cells was similarly regulated with differential expression transiently and was most abundant in 9‐day cells in vitro. PKC‐α and PKC‐β mRNAs were present at low levels throughout development in these cells, and their expression increased in 18–25 day cells. Immunocytochemical colocalization of PKC with oligodendrocyte‐specific markers—O4, galactosyl cerebroside, MBP, and PLP—in enriched oligodendrocyte cultures suggested that the PKC predominantly contributed by oligodendrocytes. PKC inhibition resulting from long‐term exposure to 4β‐phorbol‐12,13‐dibutyrate (4β‐PDB) reduced steady‐state levels of MBP, PLP, MAG, CNP, and PKC‐α mRNAs, as detected by slot blots or in situ hybridization, and downregulated the oligodendrocyte‐specific markers O4, galactosyl cerebroside, and the major consitutent proteins MBP and PLP, as detected by immunocytochemistry. PKC‐mediated downmodulation of myelin gene expression was most profound in normally differentiating oligodendrocytes at or before the onset of myelin protein synthesis. Six‐day oligodendrocytes were most susceptible to such modulation. To elucidate the mechanism of reduction in various myelin gene messages upon modulation of PKC, we analyzed mRNA levels in oligodendrocytes, which were pretreated with either the transcriptional inhibitor actinomycin D or the protein synthesis blocker cycloheximide before exposure to 4β‐PDB. Our results demonstrate that the PKC inhibition‐mediated loss in myelin mRNA levels did not require the transcription of any genes, but appeared to be at least partially dependent on continuous protein synthesis. © 1993 Wiley‐Liss, Inc.
Calpain‐mediated proteolysis of microtubule‐associated protein 2 (MAP‐2) is inhibited by phosphorylation by cAMP‐dependent protein kinase, but not by Ca2+/calmodulin‐dependent protein kinase II
Authors: Johnson Gail V. W. , Foley V. G.
Published: May 2005

The effects of cAMP‐dependent protein kinase (cAMP‐PK) and Ca2+/calmodulin‐dependent protein kinase II (CaMKII) phosphorylation on the calpain‐mediated degradation of microtubule‐associated protein 2 (MAP‐2) were studied. Both cAMP‐PK and CaMKII readily phosphorylated MAP‐2. However, cAMP‐PK phosphorylated MAP‐2 to a significantly greater extent than did CaMKII (4.5 mol 32P/mol MAP‐2 and 1.4 mol 32P/mol MAP‐2, respectively). Phosphorylation of MAP‐2 by cAMP‐PK, but not by CaMKII, significantly inhibited the calpain‐induced hydrolysis of MAP‐2. These results demonstrate that the phosphorylation of sites on the MAP‐2 molecule accessible to cAMP‐PK, but not to CaMKII, result in increased resistance to calpain proteolysis. © 1993 Wiley‐Liss, Inc.
Localization of insulin‐like growth factor binding protein‐4 expression in the developing and adult rat brain: Analysis by in situ hybridization
Authors: Brar A. K. , Chernausek S. D.
Published: May 2005

We have previously isolated insulin‐like growth factor binding protein‐4 (IGFBP‐4) from media conditioned by a neuronal cell line and have detected IGFBP‐4 mRNA in selected regions of the developing and adult rat brain by Northern blot analysis. In this study, the ontogeny and regional distribution of IGFBP‐4 expression were determined by in situ hybridization histochemistry. While IGFBP‐4 mRNA expression at embryonic day 15 was restricted to choroid plexus primordium and meninges, by embryonic day 20 IGFBP‐4 mRNA was also localized in the basal ganglia. In the postnatal rat, at days 1 and 5, IGFBP‐4 was also present in the meningeal cell layer surrounding the developing cerebellum and in the hippocampal formation. The distribution of IGFBP‐4 mRNA in the adult brain was considerably more widespread. The principal areas where IGFBP‐4 mRNA was detected were the cerebral cortex (layers II and IV), olfactory peduncle (anterior olfactory nuclei), limbic system (hippocampus and amygdala), thalamus and basal ganglia, as well as choroid plexus and meninges. The widespread and persistent expression of IGFBP‐4 is in marked contrast with IGFBP‐2, the other IGFBP in the brain, whose localization by in situ hybridization is reported to be restricted to choroid plexus and meninges. The spatial pattern of IGFBP‐4 expression in areas known to either overlap, be adjacent to, or project to regions that express the IGFs or their receptors may reflect a role for IGFBP‐4 as a modulator of IGF action in the brain. © 1993 Wiley‐Liss, Inc.
Cooperative second harmonic laser light scattering in liquid cyclohexane, benzene and carbon disulphide
Authors: Kielich S. , Lalanne J. R. , Martin F. B.
Published: May 2005

Using a Q‐switched Nd: glass laser with a high transmission optical system, first measurements of cooperative second harmonic light scattering (SHLS) in liquid cyclohexane, benzene and carbon disulphide were performed. Molecular‐statistical theory is extended to show that cooperative SHLS by liquids consisting of centro‐symmetric molecules is due to a lowering of their symmetry by the time and space fluctuating electric field of the quadrupoles and hexadecapoles of near neighbouring molecules. Also, the rôle of angular molecular correlations as well as of anisotropy in third‐order nonlinear polarisability of the scattering molecules is discussed.
Vibrational spectra of norbornadiene and the group VIB tetracarbonyl‐(norbornadiene) metal(0) complexes
Authors: Butler I. S. , Barna G. G.
Published: May 2005

The vibrational spectra of norbornadiene (NBD) and (NBD)M(CO)4 (M  Cr, Mo, W) have been investigated in detail for the first time. Partial vibrational assignments have been made for all four molecules with particular attention being paid to the C  H, CO, C  C, and M‐olefin stretching modes and the δ(CH2) bending modes. From the spectroscopic data, it appears that the C2ν geometry of the norbornadiene ligand is little affected by coordination.
Polar vibrations in crystalline hexamethylenetetramine
Authors: Bobrov A. V. , Krauzman M.
Published: May 2005

T.O.‐L.O. splitting of Polar Raman lines and polartions were observed in single crystals of hexamethylentramine.
The Raman spectrum of allene
Authors: Butcher R. J. , Jones W. Jeremy
Published: May 2005

The rotational Raman spectrum of allene has been obtained using a Fabry‐Perot etalon. Vibration‐rotation spectra of ν1, ν5, ν8 have been photographed at a resolution of 0.3 cm−1, using a 1 m spectrograph.

Analysis yielded a number of molecular constants including A0 and Dk.
Light scattering of transition metal ions. II: Correlation of electronic Raman transitions and magnetic susceptibilities
Authors: Boal D. H. , Hoff J. T. , Grunberg P. , Preudhomme J. , Koningstein J. A.
Published: May 2005

Electronic Raman transitions to levels of divalent cobalt and iron ions of the compounds CoF2, Co2GeO4 and FeF2, Fe2GeO4 are discussed. From the position and wave functions of the low lying electronic levels it is possible to calculate the magnetic susceptibility of these compounds. Our calculations suggest that a reasonable agreement exists between the calculated value from the Raman spectra and the measured values of Zm as function of the temperature of the samples.
The vibrational spectrum of sodium bromate
Authors: Berenblut B. J. , Dawson P. , Morse P. , Wilkinson G. R.
Published: May 2005

Sodium bromate is one of the few crystals which incorporate polyatomic ions in their structure and in which all the normal modes of vibration of the lattice are either Raman or infra‐red active. Thus it is an ideal meterial for investigation by the techniques of vibrational spectroscopy. Infra‐red and Raman spectra recorded at various temperatures between 15K and 300K over the frequency range 20 cm−1 to 1000 cm−1 are reported here from which a complete assignment of the zero wave vector modes is made. The results allow a test of the validity of the Lyddane‐Sachs‐Teller (LST) relationship in a fairly complex crystal with a large number of vibrational modes. Comparison of the results with those obtained in this laboratory and by other workers [1, 2] on NaClO3 leads to the tentative assignment to roatatory and translatory character of the low frequency modes.
Raman spectrum of calcium formate
Authors: Krishnan R. S. , Ramanujam P. S.
Published: May 2005

Single crystal Raman spectrum of calcium formate has been recorded and the symmetries of the various vibrations have been obtained from polarization measurements. It is found that there is a considerable splitting of the formate ion fundamental frequencies due to crystal field effects.
Étude vibrationnelle de complexes du magnesium. Spectroscopie Raman de Mg(NH3)6Cl2et Mg(ND3)6Cl2
Authors: Plus Rémi
Published: May 2005

L'auteur a pu obtenir les fréquences des vibrations actives en diffusion Raman du chlorure de magnésium hexa‐amminé hydrogéné et deutérié à l'état cristallisé. Toutes les vibrations attendues ont pu être observées pour la première fois pour un composé de ce type (vibrations internes et vibrations externes). L'attribution de toutes les bandes du spectre est proposée. Ces résultats, rapprochés de ceux obtenus par spectroscopie infrarouge, permettent de connaître la structure vibrationnelle complète du complexe. L'éclatement de certaines vibrations montre que les coordinats ne sont pas en rotation libre et que leur orientation donne à l'ion complexe la symétrie du groupe ponctuel D3d.
Charge transfer excited state of electron‐donor‐acceptor complex as an intermediate electronic state of the vibrational Raman scattering
Authors: Kaya Koji , Nakatsuka Asao , Kubota Naoki , Ito Mitsuo
Published: May 2005

The Raman spectra of the EDA complexes of tetracyanoethylene (TCNE) with benzene and methyl‐substituted benzenes were measured using four output lines of Ar ion laser. Remarkable intensity enhancements were found by the complex formation for C  C and C  N stretching vibrations of TCNE. It was concluded from measurements of Raman intensities and depolarization ratio that the intensity enhancement is due to direct participation of the lowest charge‐transfer state of the complex in the intermediate states of Raman scattering.
Raman study on para nitroaniline single crystal I: Lattice vibrations
Authors: Harrand M.
Published: May 2005

Low frequency polarized spectra were investigated from 300 to 30K; but, as accidental depolarization arises at low temperature, study was chiefly made at 300K. External vibrations have been assigned using group theory and the influence of hydrogen bonds on the motions of the molecular layers: Ag‐Bg librations at 41.6–64.8, 83.5–42.4 and 130cm−1, translations in‐plane at 79 and 94, out‐of‐plane at 144 cm−1, owing to layers. Some infrared bands have been observed and assigned.
The ν11 rotation‐vibrational Raman band of allene
Authors: Hegelund Flemming , Bendtsen Jørgen , Zangenberg Nina Rothe
Published: May 2005

The rotation‐vibrational Raman spectrum of the v11 fundamental band of allene has been recorded. The spectrum consists of a series of Q‐branches and partly resolved J‐structure in the subbands. The Q‐branches in one component of the hot band 2v11–v11 have been identified. the following constants have been obtained: v0 = 352.73 ± 0.05 cm−1, A0 = 4.811 ± 0.003 cm−1, ζ11 = 0.816 ± ± 0.001, ΔA = −0.0129 ± 0.0003 cm−1, ΔB = (4.7 ± 0.6) × 10−4 cm−1 and DK = (2.4 ± 0.1) × 10−4 cm−1. An l‐type doubling is observed and the l‐type doubling constant q is estimated as −(2.7 ± ± 0.8) × 10−4 cm−1. The analysis of the Raman spectrum shows that the assignment of the Q‐branch maxima in the infrared spectrum of v11 [4, 5] has to be changed by two units.
Automation techniques for Raman spectroscopy
Authors: Arthur J. W. , Lockwood D. J.
Published: May 2005

This paper is concerned with the automation and control of grating spectrometers by digital techniques. The methods outlined include: a simple manually operated digital control; a dedicated logic system with data storage; data acquisition and control systems run by a computer in real‐time and time‐sharing modes. The performance of these methods is evaluated. A basic spectrometer control unit is described; this unit forms a module around which more general spectrometer control systems may be constructed.
Analyse Conformationelle du Propanal et de la Butanone par Spectroscopie Raman
Authors: Chapput André , Roussel Bernard , Fleury Guy
Published: May 2005

Nous mesurons par spectroscopie Raman les variations d'intensité en fonction de la température des différentes bandes attribuées aux isomères du propanal et de la butanone en phase liquide et vapeur

Ces mesures nous permettent de calculer les variations d'enthalpie entre les conformères; la valeur de la barrière de potentiel empêchant la rotation interne du groupement CHO pour le propanal est atteinte connaissant la fréquence de torsion de ce groupement.
Raman spectrum of matrix isolated hydrogen sulfide
Authors: Tang Sheng‐Yuh , Brown Chris W.
Published: May 2005

Raman spectra of H2S isolated in N2 at M/A ratios of 30, 50, 100, and 300 and in Ar at M/A ratios of 50, 100, 300, and 1000 have been measured in the S‐H stretching region. The spectral results confirm the infrared measurements on H2S isolated in N2; however, the symmetric stretching vibration, v1, of the H2S monomer is at about the same frequency, 2619 cm−1, in the spectra of Ar matrices. This disagrees with previous infrared measurements of Ar matrices. Raman bands in the spectra of both N2 and Ar matrices due to a dimer of H2S are consistent with those observed in the infrared spectrum of N2 matrices, and they support a donor‐acceptor model for the dimer.
Depolarization ratio in preresonance Raman effect
Authors: Udagawa Y. , Iijima M. , Ito M.
Published: May 2005

The depolarization ratios of the CC stretching vibrational Raman lines of C2Cl4, C2HCl3, trans‐C2H2Cl2 were measured using visible and UV lasers. The depolarization ratios increased evidently from visible to UV excitation, and were discussed in relation to the ratio of the scattering tensor components.
Exciting frequencies and depolarization ratios for resonance Raman effects
Authors: Koningstein J. A. , Jakubinek B. G.
Published: May 2005

The behaviour of an element of the Raman scattering tensor is considered as the exciting frequency is tuned through the vibronic absorption spectrum of the scattering molecule. Certain observed features of Raman excitation profiles are explained, and some predictions made. Using some simplifying assumptions, we examine the limiting form of the scattering tensor in certain resonance situations. On the basis of symmetry considerations, we then outline expected variations in (and limits on) the depolarization ratio near resonance.
The Raman spectra of solid xenon tetrafluoride and its adduct with xenon difluoride
Authors: Adams Chris J.
Published: May 2005

The Raman spectra of the solids XeF4 and XeF2·XeF4 show effects arising in intermolecular vibrational coupling. Assignments based on factor group analysis are proposed, and the influence of intermolecular forces on the spectra of these and related compounds is discussed.
Resonance Raman spectra of chlorophyll in solution
Authors: Lutz Marc
Published: May 2005

Resonance Raman (RR) spectra of chlorophyll a and b, and of pheophytin a and b in solution are presented and their main features discussed. Variations of intensities and depolarization ratios of RR bands of the chlorophylls were followed as a function of the excitation wavelength from 441.6 to 514.5. nm. A number of band assignments are proposed. The effect of the state of association on the RR spectra of chlorophyll was studied for some typical in vitro systems. These data are discussed in view of their relevancy to the study of chlorophyll associations in vivo.
Raman spectra and lattice dynamics of the halogen cyanide crystals
Authors: Sun T. S. , Anderson A.
Published: May 2005

Raman spectra of polycrystalline samples of ClCN, BrCN and ICN have been recorded at 79 K and 18 K. The observed frequencies are compared with those obtained from lattice dynamics calculations on these linear‐chain crystals. Spectral dependence on crystallite‐size in ICN and isotope effects in all three crystals are also briefly discussed.
On the excited‐state geometry of the adenine residue as revealed by a preresonance Raman effect
Authors: Tsuboi Masamichi , Hirakawa Akiko Y. , Nishimura Yoshifumi , Harada Issei
Published: May 2005

The Raman specrum of β‐adenosine‐5′‐phosphoric acid has been observed in its aqueous solution with 6471, 5145, 4880, 4579, 4579, and 3511 Å excitation. An examination of the manner of increase of the intensities of the Raman lines at 1580 and 1484 cm−1 of the adenine residue indicated that the electronic excited state corresponding to a weak absorption band at 276 nm is responsible for these Raman scatterings. This idea has been supported by a similar examination of the Raman spectrum of β‐adenosine‐3′,5′‐cyclic phosphoric acid and an examination of the effect of temperature on the Raman spectra of poly rA and poly(rA‐rU). A discussion is included of the geometrical structure of the adenine residue in its lowest‐singlet electronic excited state, based on the vibrational structure of the fluorescence spectrum, the result of a normal coordinate treatment, and the result of a semiempirical Pariser‐Parr‐Pople calculation, as well as the Raman data.
Raman scattering by polaritons under nonstationary conditions. I: The basic principles of the general theory
Authors: Marchevskii F. N. , Strizhevskii V. L.
Published: May 2005

The fluctuation‐dissipation method of theoretical investigation of stimulated Raman scattering (RS) by polaritons in piezoelectric crystals under nonstationary conditions taking into account both wave and local nonstationary cases in the fixed pump field approximation has been carried out. The method is based on solving the reduced operator equations in partial derivatives for Stokes and polariton fields coupled by the pump field. The equations contain the noise sources – polariton fluctuations whose properties are defined by the fluctuation‐dissipation theorem. The Stokes and polartion field are described in the quantum language as the operators in Heisenberg representation. Quantum description of fields is necessary for correct account of the initial fluctuations and is also essential for the right transition to the particular case of spontaneous RS. The energy characteristics, which describe the angular‐frequency distribution of Stokes and polariton radiation are calculated by means of quantum statistical averaging of the corresponding field combinations. Their general connection with the correlative functions, which define initial and boundary field fluctuations is found.
Raman spectra of methyl‐dichloro‐sulphonium(IV) hexachloroantimonate(V)‐[CH3SCl2]+ [SbCl6]−
Authors: Shamir Jacob
Published: May 2005

The Raman spectra of methyl‐dichloro‐sulphonium hexachloroantimonate was studied, both in the solid state and in acetonitrile solution. Polarization measurements were made for the solution and an assignment of the observed frequencies is given and discussed.
Electronic Raman scattering by Germanium p‐acceptors and luminescence in GaAs
Authors: Scheuermann W.
Published: May 2005

The Raman spectrum of Germanium p‐doped epitaxial GaAs layers (p ∼ 1 × 1016 cm−3) has been recorded at 300 and 5.5 K with a YA1G:Nd3+ laser at 1.064 μm as exciting source. The special sample arrangement used to observe the Raman scattering from the 30 μm thin layers is described in detail. Raman scattering from neutral acceptor levels of the dopant Ge was observed at 5.5K at 230 cm−1 = 28.5 meV and at 248 cm−1 = 30.7 meV. Strong luminescence of the sample was also observed at 5K with two prominent peaks at 924.5 nm and 942.0 nm.
Resonance Raman spectra of iodine adsorbed on silicas
Authors: Nagasao Tsutomu , Yamada Haruka
Published: May 2005

The resonance Raman effect has been applied for the first time to the study of the structure of adsorbed molecules and the interaction between adsorbents and adsorbates. By rotating a sealed sample and using Ar+ laser excitation, the resonance Raman spectrum of I2 adsorbed on the silicas was measured for the second to the fifth harmonics. The peak frequencies were slightly shifted from those for the gas molecule, indicating the weak bondage between the surface OH groups and iodine molecules. When iodine monochloride was adsorbed on a silica surface, the resonance Raman spectrum of I2 adsorbed on silicas was also observed.
Polar phonons in crystalline glycerol
Authors: Beaudoin Jean Louis
Published: May 2005

The polarized Raman spectrum of some oriented glycerol single crystals have been recorded from 115 to 273 K. The LO–TO splittings have been measured for most of the fundamental vibrations. Some results relating mainly to OH vibrations and lattice vibrations, are presented. Hydrogenbonds appear to be preponderant in intermolecular interactions. A calculation of intermolecular force constants has been performed, which confirms this conclusion.
Laser optical saturation of molecular reorientation in Raman light scattering
Authors: Kielich S. , Ożgo Z. , Wołejko L.
Published: May 2005

Raman scattering by molecules and macromolecules, arrayed in the electric field of an intense laser beam, is analyzed. Nonlinear changes in the intensity of light scattered by linear and symmetric‐top molecules are calculated and expressed in terms of even‐order generalized Langevin reorientation functions for all types of Raman‐active vibrations. It is shown that the Raman line intensity can undergo an abatement or an enhancement as a result of reorientation, induced by laser radiation; the analysis of these changes in intensity provides additional information on the Raman polarizability tensor, particularly on the sign and magnitude of its anisotropy.
Raman spectroscopic studies of several phases in the ex‐hen egg lecithin/water system
Authors: Faiman Rosalind , Long D. A.
Published: May 2005

Raman spectroscopic studies of egg‐lecithin/water systems over the temperature range −30 to 20°C and water content 1.0 to 30% are reported. It is found that changes in the vibrational Raman spectra can be related to the conformation of the hydrocarbon chains in the various phases of the egg‐lecithin/water systems studied.
A versatile computer‐controlled spectrometer for hyper Rayleigh and hyper Raman spectroscopy
Authors: French M. J. , Long D. A.
Published: May 2005

The construction, operation and performance of a versatile, computer‐controlled spectrometer for the observation of hyper Rayleigh and hyper Raman scattering is described. The instrument may be operated either in a single channel mode using as the detector a photomultiplier, or in a multi‐channel mode using as the detection system a high‐gain image intensifier coupled to a television camera. Typical spectra; obtained with this instrument are presented.
Raman spectra of platinum hematoporphyrin complexes
Authors: Berjot M. , Bernard L. , Macquet J. P. , Theophanides T.
Published: May 2005

The laser Raman spectra of the solid hematoporphyrin free‐base H2Hem, the diacid, [H4Hem]2+ and the platinum complexes, [H4Hem]2+ [PtCI4]2−, the Sitting‐Atop complex (SAT), cis‐Pt(H2Hem) Cl2 and the platino‐hematoporphyrin PtHem have been studied in the range 500 to 1800 cm−1. The spectra of the platinum complexes are significantly different from those of hematoporphyrin and changes of the band profiles upon incorporation of the platinum atom into the porphyrin plane are shown. An interesting change is observed in the series H2Hem → cis‐Pt(H2Hem) Cl2 → PtHem in the region 1300–1650 cm−1. The Raman lines in this region are normally assigned to the vibrational modes of CC and CN. The Raman spectra provide another evidence of the existence of the SAT complex.
Evidence of ion‐pairing in the polarized Raman spectra of a Ba2+CrO doped KI single crystal
Authors: Grzybowski Joseph M. , Khanna R. K. , Lippincott E. R.
Published: May 2005

The polarized Raman spectrum of a dilute solid solution single crystal of Ba2+CrO doped in KI has been obtained. The polarization data confirm the previous assignments based on infrared absorption investigations alone. The Raman polarization measurements strongly indicate the presence of non‐randomly oriented Ba2+CrO ion pairs possessing mainly C2ν and Cs site symmetries.
Preresonance Raman spectra of simple amides using ultraviolet lasers
Authors: Harada Issei , Sugawara Yoko , Matsuura Hiroatsu , Shimanouch Takehiko
Published: May 2005

The Raman spectra of N‐methylacetamide, N‐ethylacetamide, and N‐methylpropionamide have been recoraed using the laser lines at 6471 Å, 4765 Å, 4762 Å, 3507 Å. and 2573 Å for excitation. Appreciable intensity enhancement has been observed for the amide I and III lines in the UV excited spectra; the amide II lines show up clearly in the spectra using 2573 Å excitation, and the G‐methyl and N‐methyl symmetric deformation lines are also enhanced. The possible usefulness of the Raman spectra of peptide molecules obtained using ultraviolet excitation is discussed.
Spectra and structure of organophosphorous compounds. XII:Infrared and Raman Spectra of (CH3)2PH and (CD3)2PH
Authors: Durig J. R. , Saunders J. E.
Published: May 2005

The vibrational spectra of (CH32PH) and (CD3)2PH have been studied and assignments made. In the infrared, the region 4000–33 cm−1 was recorded for the gaseous and solid states whereas the Raman spectra from 3500–10 cm−1 in the gaseous, liquid, and solid states were observed. There is some evidence of weak hydrogen bonding based on the behavior of the phosphorus‐hydrogen stretching and bending modes. There also appears to be considerable interaction between the metnyl rocking and phosphorus‐carbon stretching modes. The a″ and a′ torsional modes appear to be accidentally degenerate at 182 and 142 cm−1 for the ‘light’ and ‘heavy’ compounds, respectively, which gives barriers of 2.14 and 2.30 kcal mole−1, respectively.
Raman scattering of lattice vibrations in H4‐urea and D4‐urea
Authors: Lefebvre J. , Fontaine H. , Fouret R.
Published: May 2005

The five external vibrational modes of h4‐urea and of d4‐urea active in Raman scattering have been measured at room temperature and at 100K. It is shown that the A1 mode has a frequency close to 100 cm−1 at room temperature. It has been possible to interpret the angular dispersion of one of the external polar modes by the dynamical matrix, which has also enabled us to calculate the permanent dipole moment of the molecule of urea. The value obtained, ∼ 3 Debyes at room temperature for h4‐urea and d4‐urea, is accounted for by the hypothesis of ionized hydrogen bonds.
Spectres de diffusion Raman et structure des monocristaux de Mg(H2PO2)2 6H2O et Co (H2PO2)2 6H2O
Authors: Abénoza Michel , Martin Louis
Published: May 2005

Single crystal Raman spectra of Mg (H2PO2)2 6 H2O, Mg (H2PO2)2 and Co (H2PO2)2 6 H2O) were recorded.

A complete assignment of the bands to the zero wave vectors modes is proposed. The comparison between calculated and experimental Raman intensities shows the individuality of the H2PO ions in the crystal. Various structure hypotheses are discussed: only the Lopez de Lerma's hypothesis and the 𝒮4 site symmetry for the magnesium (or cobalt) atom are compatible with the Raman spectra data of the three single crystals.
The solid state vibrational spectra of s‐triazine and s‐triazine‐d3 and the monoclinic to rhombohedral phase transition
Authors: Daunt S. J. , Shurvell H. F. , Pazdernik L.
Published: May 2005

Infrared and Raman spectra of polycrystalline s‐triazine and s‐triazine‐d3 have been recorded over a wide range of temperatures. The spectra of the high temperature phase are in agreement with predictions based on the reported D3d6 rhombohedral crystal structure. The spectra of the low temperature monoclinic phase are compatible with a unit cell of symmetry C2h with two molecules in Cs or C2 sites. Possible space groups are C2hi; i =1,2,3,4, or 6. The higher order nature of the rhombohedral to monoclinic phase transition is indicated by the gradual increase in splitting of degenerate modes in the infrared and Raman spectra of both C3N3H3 and C3N3D3 as the temperature was lowered. From studies of these splittings up to the phase change, the transition temperature was found to be 200±5K for C3N3H3 and 190±5K for C3N3D3.
Spectres de vibration et structure du nitrate d'uranyle et de rubidium et du sel isomorphe de cesium
Authors: Caville C.
Published: May 2005

Les spectres de Raman de monocristaux et les spectres d'absorption IR des poudres sont enregistrés à température ambiante. La fréquence de la vibration antisymétrique de l'ion uranyle est détectée dans les spectres de Raman; ce mode est interdit par les règles de sélection du système trigonal R3C(D). Nous sommes en accord avec une forme pseudotrigonale mais la structure monoclinique C2/m, proposke par rayons X, doit être reconsidérée.