bluuebunny/crossref_metadata_2025_split huggingface dataset:
ApoC‐I and ApoC‐III as potential plasmatic markers to distinguish between ischemic and hemorrhagic stroke
Authors: Allard Laure , Lescuyer Pierre , Burgess Jennifer , Leung Kit‐Yi , Ward Malcolm , Walter Nadia , Burkhard Pierre R. , Corthals Garry , Hochstrasser Denis F. , Sanchez Jean‐Charles 
Published: June 2004

AbstractEarly diagnosis and immediate therapeutic interventions are crucial factors to reduce the damage extent and the risk of death. Currently, the diagnosis of stroke relies on neurological assessment of the patient and neuro‐imaging techniques including computed tomography and/or magnetic resonance imaging scan. An early diagnostic marker of stroke, ideally capable to discriminate ischemic from hemorrhagic stroke would considerably improve patient acute management. Using surface‐enhanced laser desorption/ionization (SELDI) technology, we aimed at finding new early diagnostic plasmatic markers of stroke. Strong anionic exchange (SAX) SELDI profiles of plasma samples from 21 stroke patients were compared to 21 samples from healthy controls. Seven peaks appeared to be differentially expressed with significant p values (p < 0.05). Proteins were stripped from the SAX chips, separated on a one‐dimensional electrophoresis (1‐DE) gel and stained using mass spectrometry (MS)‐compatible silver staining. Following in‐gel tryptic digestion, the peptides were analyzed by MS. Four candidate proteins were identified as apolipoprotein CI (ApoC‐I), apolipoprotein CIII (ApoC‐III), serum amyloid A (SAA), and antithrombin‐III fragment (AT‐III fragment). Assessment of ApoC‐I and ApoC‐III levels in plasma samples using a sandwich enzyme‐linked immunosorbent assay (ELISA) allowed to distinguish between hemorrhagic (n = 15) and ischemic (n = 16) stroke (p < 0.001). To the best of our knowledge, ApoC‐I and ApoC‐III are the first reported plasmatic biomarkers capable to accurately distinguish between ischemic and hemorrhagic stroke in a small number of patients. It requires further investigation in a large cohort of patients.
Some physical properties of polyorganosiloxanes. I. Linear polyorganosiloxanes
Authors: Andrianov K. A. , Slonimskiĭ G. L. , Zhdanov A. A. , Yu. Levin V. , Godovskiĭ Yu. K. , Moskalenko V. A. 
Published: June 2004

AbstractSome physical properties of linear polydimethylsiloxanes have been studied. The states and transitions in polydimethylsiloxanes have been investigated by using the method of dynamic heat capacity and a thermomechanic method in the temperature range from −150 to +200°C. The temperature dependence of primary and secondary crystallization has been studied by optical, calorimetric, and x‐ray methods.
Molecular parameters of sodium amylose xanthate in dilute solution
Authors: Manna P. K. , Choudhury P. K. 
Published: June 2004

AbstractMolecular parameters of sodium amylose xanthate in 1N NaOH solution have been determined by means of light scattering and viscometry. The expansion factor, α, has been determined from the expression due to Orofino and Flory. The value of a of the Mark‐Houwink relation, [η] = KMa, has been determined. The Stockmayer‐Fixman relationship has been used to evaluate the unperturbed dimension of the chain. The effective bond length b, Kuhn‐Kuhn equivalent chain segment length Am and the steric factor σ, i.e., the ratio of the unperturbed dimension to the dimension assuming free rotation of the chain \documentclass{article}\pagestyle{empty}\begin{document}$(\bar R_o^2 )_z ^{1/2} /(\bar R_f^2 )^{1/2}$\end{document} have also been determined. From these data, it is concluded that sodium amylose xanthate in 1N NaOH solution behaves as a loosely coiled molecule.
Cationic copolymerization of anethole: Reactivity of geometric isomers of α,β‐disubstituted ethylenes
Authors: Higashimura T. , Kawamura K. , Masuda T. 
Published: June 2004

AbstractCationic copolymerizations of anethole were carried out under various conditions in order to confirm the relative reactivities of its geometric isomers. trans‐Anethole was more reactive than cis‐anethole in copolymerizations with p‐methoxystyrene or styrene, but less reactive in the mutual copolymerization of cis‐ and trans‐anethole; i.e., the trans isomer was more reactive to a growing chain end with little steric hindrance. Thus the intrinsic reactivity of an olefinic double bond to carbonium ion is greater for the trans isomer than for the cis isomer. This idea is supported by 13C NMR spectra, since the signal of the olefinic β‐carbon of the trans isomer is at higher field than that of the cis isomer. The behavior of anethole was compared with the results observed in vinyl ethers, where the cis isomer was always more reactive irrrspective of the structure of the growing chain end. In addition, the dependence of monomer reactivity ratios on polymerization conditions is discussed.
Photosensitized dehydrochlorination of poly(vinyl chloride)
Authors: Owen E. D. , Bailey R. J. 
Published: June 2004

AbstractThe mechanism of the benzophenone‐photosensitized degradation of films of poly‐(vinyl chloride) was studied, both under vacuum and in the presence of oxygen. Initial rapid increases in absorption in the 340 nm region strongly implicate the ketyl radical in the initiation process which involves the abstraction by triplet benzophenone of a methylenic hydrogen from poly(vinyl chloride). Dehydrochlorination then occurs by a chain mechanism, and the conjugated polyene structure produced photosensitizes further initiation and, in the presence of oxygen, photo‐oxidation of the polymer.
Electron spin resonance study of poly‐3,3‐bis‐(chloromethyl)oxetane irradiated with ultraviolet light
Authors: Tsuji Kozo , Seiki Toshifumi 
Published: June 2004

AbstractWhen poly‐3,3‐bis(chloromethyl)oxetane has been irradiated at −196°C in a nitrogen atmosphere with ultraviolet light, a triplet spectrum is observed. After warming the sample, both a doublet and a singlet ESR spectra are observed. These spectra are attributed to and CH2O, respectively. The formation mechanism of these free radicals is discussed. It is concluded that the main process of radical formation is the dissociation of chemical bonds from the excited state of the polymer produced through the energy absorption by irregular groups acting as sensitizers. In the presence of oxygen, the radical yield at −196°C is greater than that in nitrogen atmosphere. This is attributed to the extra absorption of light by the charge transfer complexes of polymers with oxygen molecules. It is also proposed that participation of a charge transfer complex in photooxidation of ether is important in the primary radical formation step. When a polymer sample irradiated in vacuum with ultraviolet light is treated at −78°C for a few minutes in the presence of air, peroxy radicals form. This shows that oxygen molecules diffuse very easily into this polymer, even at this low temperature.
Cyclopolymerization of divinyl esters of dibasic acids and structure of poly(vinyl alcohol) derived from the polymers
Authors: Kikukawa Kiyoshi , Nozakura Shun‐Ichi , Murahashi Shunsuke 
Published: June 2004

AbstractDivinyl esters of dibasic acids, CH2CHOCO(CH2)n−2COOCHCH2, n = 2–10, were synthesized and polymerized with a radical initiator, and the structure of poly(vinyl alcohol)(PVA) derived from the polymers were studied. The cyclopolymerizability of these monomers was nearly equal to or less than that of divinyl carbonate which was previously reported, and the extent of cyclization was 15–65%. All the monomers yielded gelled polymers. The monomers which are to yield even‐membered rings tend to cyclopolymerize more easily than those of odd‐membered rings. PVA derived from these polymers showed a similar structure with respect to 1,2‐glycol content and stereoregularity to that from poly(vinyl acetate).
Formation of block copolymers from polyurethanes containing reactive disulfides
Authors: Fildes F. J. T. , Tobolsky A. V. 
Published: June 2004

AbstractBlock copolymers containing polyether segments and segments of a vinyl polymer have been synthesized. A low molecular weight polyether terminated with isocyanate groups was condensed with bis‐(β‐hydroxyethyl disulfide) to give polyurethanes containing reactive disulfide linkages. When this polymer was photolyzed in the presence of a vinyl monomer such as styrene, methyl methacrylate, or acrylonitrile, homolytic cleavage of the disulfide polymerized the monomer, giving block copolymers. The mechanical properties of the products were investigated by means of modulus–temperature measurements.
Universal calibration in GPC
Authors: Rudin Alfred , Hoegy Howard L. W. 
Published: June 2004

AbstractThe M[η]‐elution volume calibration curve for gel‐permeation chromatography (GPC) is based on the implicit assumption that the hydrodynamic volume of a solvated polymer species in the GPC columns is that which pertains at infinite dilution. This is not true of highly solvated high molecular weight fractions and results in apparent failure of this calibration in some instances. A model is presented to estimate hydrodynamic volumes of polymers at finite concentrations. The parameters required are polymer concentration, molecular weight, amorphous density, and the Mark‐Houwink constants for the particular polymer–solvent combination. The calculated log (hydrodynamic volume)–elution volume relation provides a universal GPC calibration. The model accounts for the occasional shortcomings of the infinite dilution calibration and is essentially equivalent to it in noncritical cases. The use of the proposed calibration method is illustrated.
Polymerizations of vinyl methacrylate and vinyl acrylate
Authors: Fukuda Wakichi , Nakao Masahiro , Okumura Kinichi , Kakiuchi Hiroshi 
Published: June 2004

AbstractBoth vinyl methacrylate (VMA) and vinyl acrylate (VA) were homopolymerized by n‐butyllithium catalyst at −78°C. Both of the anionic polymers were soluble in common organic solvents, and only vinyl group was contained in the polymers. Both of the monomers were homopolymerized by free‐radical catalysts under different conditions. The soluble polymers were obtained under low monomer concentrations and at low conversions. It was estimated by NMR and infrared spectroscopy that both the soluble polymers contained mainly a vinyl group, similar to the anionic polymers. The soluble VMA polymers comprised 10–20% cyclic units for monomer concentrations ranging from 1.8 to 0.5 mole/I. The soluble VA polymers comprised 50–60% cyclic units for monomer concentrations ranging from 0.9 to 0.3 mole/l. It was suggested that the cyclic units did not consist of γ‐lactone but of larger‐membered rings than δ‐lactone or of ladder structural units. The difference between the cyclization content of poly‐VMA and that of poly‐VA might be explained by the copolymerization data of the reference monomers.
Oxidation of polyethylene, polypropylene, and copolymers
Authors: Van Sickle Dale E. 
Published: June 2004

AbstractThis investigation of the autoxidation of ethylene–propylene copolymers and polyethylene–polypropylene mixtures was undertaken to determine whether reactivity is a linear function of composition. The copolymers and the mixtures were autoxidized in a trichlorobenzene solution at 100°C in the presence of 1,1′‐azodicyclohexanecarbonitrile, and the rates of oxygen absorption were determined. The reactivity of the copolymers and the mixtures, after the underlying absorption of oxygen by initiator radicals is accounted for, is a nearly linear function of composition; however, the polymer mixtures and copolymers oxidized somewhat less readily than predicted by a straight line relationship. Several additional oxidations were performed on solutions of polypropylene so that the effects of initiation rate and substrate concentration could be evaluated. The oxidation kinetics of polypropylene even in dilute solution, are complex; titratable hydroperoxide yields are low. Further work will be required to specify the mechanism of oxidation.
Dynamics of spherulitic growth in blends of polypropylene isomers
Authors: Mehta Rujul , Kyu Thein 
Published: June 2004

AbstractThe spatiotemporal growth of spherulites in blends of isotactic polypropylene (iPP) and atactic polypropylene (aPP) isomers has been investigated theoretically with the time‐dependent Ginzburg–Landau equation, which consists of a nonconserved crystal order parameter and a conserved compositional order parameter. In the description of the total free energy, a local free energy density in the form of an asymmetrical double well, signifying the metastability and latent heat of crystallization, is combined with a nonlocal free energy term representing the interface gradient. In addition, the Flory–Huggins free energy for mixing between iPP and aPP isomers has been employed to account for blend miscibility. Two‐dimensional simulations have been carried out, based on the known material parameters of blends of iPP and aPP. The rejection of aPP from the growing spherulitic front has been modeled for comparison with the reported experimental observations. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2892–2899, 2004
A new thermoplastic vulcanizate (TPV)/organoclay nanocomposite: Preparation, characterization, and properties
Authors: Mishra Joy K. , Kim Gue‐Hyun , Kim Il , Chung In‐Jae , Ha Chang‐Sik 
Published: June 2004

AbstractThe preparation, characterization, and properties of the new thermoplastic vulcanizate (TPV)/organoclay nanocomposites are reported in this article. The nanocomposites were prepared by the melt intercalation method. The organoclay was first treated with glycidyl methacrylate, which acts as a swelling agent for organoclays, as well as a grafting agent for TPV (in the presence of dicumyl peroxide) during the melt mixing. The nanocomposite was intercalated, as evidenced by X‐ray diffraction. The tensile modulus of the 5% TPV/organoclay nanocomposite was higher than that of the 20% talc‐filled microcomposite. The storage modulus of the nanocomposite was higher than that of the pristine TPV. The most important observation is obtained from dynamic mechanical analysis, which reveals that the glass‐transition temperature of the polypropylene phase of the nanocomposite increases (as compared to virgin TPV), whereas the ethylene–propylene–diene monomer phase remains almost the same. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2900–2908, 2004
Impact of a 100‐year flood on vegetation, benthic invertebrates, riparian fauna and large woody debris standing stock in an alpine floodplain
Authors: Hering Daniel , Gerhard Marc , Manderbach Randolf , Reich Michael 
Published: June 2004

AbstractThis paper investigates the impact of a 100‐year flood in May 1999 on community composition and large woody debris standing stock in an alpine floodplain (Isar, Germany). Detailed pre‐flood data sampled from 1993 to 1998 are compared with the situation directly after the flood. In those parts of the Isar floodplain mainly covered with pioneer vegetation prior to flooding, the coverage of unvegetated gravel bars increased by 22% following the flood. However, the flood did not remove larger amounts of older successional vegetation stages (willow thickets, floodplain forest). No significant changes in the benthic invertebrate fauna were recorded. The lowest densities of riparian ground beetles (Carabidae) within the study were recorded one month after the flood. Two months later, the ground beetle densities increased to the highest values ever recorded, indicating the ground beetle's high potential for recolonization. These results highlight the degree of resilience of both the aquatic and the riparian invertebrate fauna. The flood also caused a significant increase in large woody debris standing stock; in one section the number of logs increased tenfold and the volume increased by a factor of 20, leading to the assumption that most woody debris in alluvial flood‐plains is provided by catastrophic events. Copyright © 2004 John Wiley & Sons, Ltd.
Differences in intramembrane particle distribution in young and old human erythrocytes
Authors: Cordero Julio F. , Rodrıguez Pedro J. , Romero Pedro J. 
Published: June 2004

AbstractThe distribution of intramembrane particles in human erythrocytes was studied by freeze‐fracture on young and old cells and compared to that obtained after ATP depletion or following addition of a clustering agent. It was shown that intramembrane particles became aggregated and the mean particle density increased as the cells aged. Likewise, both particle aggregation and increased density were found in young cells after moderate ATP depletion. In contrast, mean particle density was markedly reduced in both cell types after exhaustive depletion. Paradoxically, Zn treatment led to decreased particle density in young cells, whilst producing the opposite effect in aged cells. The results suggest that their low ATP content may account for the increased particle density of senescent cells.
THE RELATION OF DEXTROSE TO THE PRODUCTION OF TOXIN IN BOUILLON CULTURES OF THE DIPHTHERIA BACILLUS
Authors: Smith Theobald 
Published: June 2004

1. Dextrose is not in itself injurious but rather favorable to toxin production. When added in quantities not exceeding 0.2 per cent to peptone bouillon freed from fermentable acid-producing substances (muscle sugar) it leads to a maximum accumulation of toxin by utilizing the available peptone to the best advantage.
2. The different courses taken by cultures of diphtheria bacilli in ordinary unfermented peptone bouillon containing muscle sugar and in peptone bouillon made from fermented infusion to which 0.1 to 0.2 per cent dextrose has been added are manifested by an increased production of toxin in the latter as well as by a rapid return from an acid to an alkaline reaction. In the former an acid reaction may prevail even under most favorable conditions.
3. These differences may be explained by assuming either that the acid products of the muscle sugar are different from those of dextrose and non-utilizable, or else that the bouillon contains certain other unknown inhibitory substances removed during fermentation. The use of synthesized media and an analysis of the acid products in fermented bouillon plus dextrose and in unfermented bouillon would aid in explaining the differences.
4. Among the accessory conditions which favor the toxin production in unfermented bouillon, as pointed out by Park and Williams, are increased quantities of peptone, well developed surface growth of the diphtheria bacilli, and a low initial acid reaction (phenolphthalein). In fermented bouillon these accessory conditions are also favoring, though of legs importance.
BACILLUS PYOCYANEUS AND ITS PIGMENTS
Authors: Jordan Edwin O. 
Published: June 2004

The principal conclusions that seem to me justified are as follows:
1. The fluorescent pigment formed by some varieties of B. pyocyaneus is produced under conditions identical with those governing the production of the pigment by other "fluorescent bacteria."
2. The production of pyocyanin is not dependent upon the presence of either phosphate or sulfate in the culture medium. It is formed in non-proteid as well as in proteid media, but is not a necessary accompaniment of the metabolic activities of the organism (e. g. tartrate solution).
3. The power of producing pyocyanin under conditions of artificial cultivation is lost sooner than the fluorescigenic power.
4. There are greater natural and acquired differences in pyocyanigenic power than in fluorescigenic.
5. The fluorescent pigment may be oxidized slowly by the action of light and air as well as by reagents into a yellow pigment, and pyocyanin may be similarly oxidized into a black pigment.
6. A convenient separation of B. pyocyaneus into four varieties would be the following: var. α, pyocyanigenic and fluorescigenic (most common); var. ß, pyocyanigenic only (rare); var. γ, fluorescigenic only (not uncommon, closely related to "B. fluorescens liquefaciens"); var. δ, non-chromogenic.
7. Except for the occasional loss of one or another function the different varieties are not so plastic as sometimes assumed, and cannot be readily converted into one another by subjection to varying conditions of life.
8. The signification and correlation of the almost countless physiological variations among the members of this group in respect to growth in gelatin, behavior to temperature, indol production, etc., remain to be determined. It is not yet clear that the variations in chromogenic power can be in any way correlated with the presence or absence of other physiological functions.
THYMECTOMY IN THE RABBIT
Authors: Van Allen Chester M. 
Published: June 2004

Thymectomy in the rabbit is a comparatively simple procedure. The open method described above offers many advantages over any of the closed methods and success depends largely upon the observance of a few precautions; chief among these is the avoidance of haste and the observance of aseptic technique.
The operative mortality in our series of rabbits was 10 per cent and there was an additional loss of useful animals, due to secondary complications, amounting to 16 per cent. Among the last 29 rabbits, however, there was only 1 operative death, in an old animal, and 2 cases of slight infection. It appears, therefore, that with some experience the operation can be carried out successfully in nearly all animals, especially so if comparatively young rabbits are used. Old rabbits present greater difficulties on account of the presence of dense fibrous tissue within the field of operation.
While the animals of this series showed no immediate symptoms or alteration in physical condition that could be referred to thymoprivia, it is not to be assumed that removal of the thymus is entirely without effect even on rabbits of mature age. Our observations on the reaction of thymoprivic rabbits to disease show that this is not the case and that in all probability decided effects can be demonstrated if the problem is approached on another basis. The object of the present investigation was, however, to determine whether the thymus could be completely removed from rabbits of certain ages without producing any serious disturbance of health which would interfere with their use in other experiments or complicate the interpretation of results. It was found that this could be done.
STUDIES ON THE TOXIN PRODUCTION OF THE SHIGA BACILLI
Authors: Waaler Erik 
Published: June 2004

1. The S, R, and Rn variants of the Shiga bacillus are equally toxic.
2. The effect of the toxin upon rabbits is the same, whether it is derived from filtrates of broth cultures (3 to 6 days old), or is obtained by autolysis of the killed bacteria, grown on agar surface. Rabbits show in both cases prostration, loss in weight, paralysis, and diarrhea.
3. When the toxin is heated to 80°C. for 1 hour, its poisonous effect nearly disappears, but its immunizing ability is unaltered. This heated toxin induces a formation of antitoxin, which can protect against the unheated toxins.
4. The anatomical changes observed in the spinal cord (degeneration of the motor neurons) and in the cecum (hyperemia and hemorrhages) are in agreement with the statements of previous authors. Furthermore, the toxin causes hyperemia and hemorrhages in the heart, hyperemia and degeneration in the kidneys and the liver.