bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nuclear ultrastructures associated with the RNA synthesis and processing
Authors: Raška Ivan 
Published: May 2005

AbstractRelatively 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

AbstractEvidence 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

AbstractIn 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

AbstractA 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

AbstractThe 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

AbstractWater 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

AbstractThe 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

AbstractOxidation 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

AbstractThis 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

AbstractTriglycerides 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

AbstractThin‐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

AbstractChanges 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

AbstractAs 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

AbstractIn 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

AbstractPrevious 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

AbstractTheneugene, 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

AbstractCultured 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

AbstractResonance 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

AbstractLes 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractDepolarization 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

AbstractRaman 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

AbstractThe 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).