bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Crystal Structure of the Clathrate Forms of Syndiotactic Polystyrene Containing Carbon Disulfide and Iodine
Authors: Tarallo Oreste , Petraccone Vittorio 
Published: June 2004

AbstractSummary: The crystal structure of the clathrate form of syndiotactic polystyrene containing different amounts of CS2 has been analyzed, and compared with that of the clathrate containing I2. These two guest molecules, which are characterized by a similar shape and volume, give rise to the only two known examples of clathrate forms containing up to two molecules per cavity. The two structures are isomorphous both in the case of complete and of partial occupation of the cavities. In the second case, CS2 and I2 molecules when alone in the cavity occupy almost identical positions at its center. Some of the literature on the crystal structure of these two clathrates is ambiguous and this is discussed. A comparison with the CS2 clathrates of syndiotactic poly(p‐methylstyrene) and poly(m‐methylstyrene) is also made.Schematic representation of the two ways in which guest molecules can be hosted in the cavities of the crystals of the s‐PS clathrate form containing carbon disulfide.magnified imageSchematic representation of the two ways in which guest molecules can be hosted in the cavities of the crystals of the s‐PS clathrate form containing carbon disulfide.
Area enlargement of the gracilis muscle flap through microscopically aided intramuscular dissection: ideas and innovations
Authors: Huemer Georg M. , Dunst Karin M. , Maurer Herbert , Ninkovic Milomir 
Published: June 2004

AbstractThe gracilis muscle is one of the most extensively used muscles for free tissue transplantation. Its advantages are low donor‐site morbidity with a concealed donor scar, a constant anatomy with large‐diameter vessels, and the potential for a neurosensory flap as well as a large skin paddle. However, limitations comprise its limited size, and thus the muscle is limited to small‐to‐medium‐sized defects. We present a novel technique by which the muscle can be enlarged 3–4 times over the regular muscle width. This can be achieved by microscopically aided intramuscular dissection of connective tissue with preservation of the intrinsic vessels of the muscle. With this technique, the field of application of the versatile gracilis muscle in reconstructive surgery can be further expanded. © 2004 Wiley‐Liss, Inc. Microsurgery 24:1–4 2004.
Effect of number of fascicle on axonal regeneration in cable grafts
Authors: Okuyama Noriko , Nakao Yasushi , Takayama Shinichiro , Toyama Yoshiaki 
Published: June 2004

AbstractThe effect of number of fascicles on axonal regeneration in cable grafts was examined in the rat cable graft model. The study comprised three experimental groups: the 5f‐group, which received 5 fascicles, larger than the host; the 3f‐group, in which the total area of the graft fascicles was similar to that of the host; and the 1f‐group, which received one fascicle cable graft, smaller in diameter than the host nerve. At the graft segment, well‐myelinated fibers were observed both inside and outside the graft fascicles. The three groups showed no difference in morphometric and functional assessment, suggesting that the fibers which regenerated through the outside of the graft might be effectively induced into the distal host. The disproportionate enlargement of the graft fascicle of the 1f‐group also increased the fibers passing through it. These findings suggest that a small number of fascicles can induce a larger population of regenerated fibers in the 20‐mm cable graft model. © 2004 Wiley‐Liss, Inc. Microsurgery 24:1–8 2004.
Weighted proportional loss rate differentiation of TCP traffic
Authors: Aweya James , Ouellette Michel , Montuno Delfin Y. 
Published: June 2004

AbstractRelative service differentiation refers to service models that provide assurances for the relative quality ordering between classes, rather than for the absolute service level in each class. An example is the proportional differentiation model which provides a way to control the quality spacing between classes locally at each hop. In this model, certain forwarding metrics are ratioed proportional to the class differentiation parameters that the network operator chooses. In this paper, we propose a new proportional loss rate differentiation mechanism that integrates relative loss rate differentiation directly into active queue management using random early detection. Copyright © 2004 John Wiley &Sons, Ltd.
Diverse and potent activities of HGF/SF in skin wound repair
Authors: Bevan Damon , Gherardi Ermanno , Fan Tai‐Ping , Edwards Dylan , Warn Richard 
Published: June 2004

AbstractGenetic studies in the mouse have highlighted essential roles for several growth factors in skin repair and have offered a rationale for their use in therapy. The present study shows that the plasminogen‐related growth factor HGF/SF (hepatocyte growth factor/scatter factor) promotes wound repair in homozygous diabetic db/db mice by recruiting neutrophils, monocytes, and mast cells to the wound; by promoting the migration of endothelial cells to the injured area; and by enhancing keratinocyte migration and proliferation. As a result, granulation tissue formation, wound angiogenesis, and re‐epithelialization are all increased. The results demonstrate that HGF/SF affects and sustains all key cellular processes responsible for wound repair and point to a unique potential of this molecule for the therapy of chronic skin wounds. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Distinct expression patterns of the transcription factor E2F‐1 in relation to tumour growth parameters in common human carcinomas
Authors: Zacharatos Panayotis , Kotsinas Athanassios , Evangelou Konstantinos , Karakaidos Panagiotis , Vassiliou Leandros‐V , Rezaei Nousin , Kyroudi Aspasia , Kittas Christos , Patsouris Eystratios , Papavassiliou Athanasios G , Gorgoulis Vassilis G 
Published: June 2004

AbstractE2F‐1 is a pivotal transcription factor that integrates signals from a variety of G1/S phase regulators and modulates diverse cellular functions, such as DNA synthesis, repair, mitosis, and apoptosis. Its role in cellular proliferation and apoptosis, as depicted from experimental models and limited reports in human malignancies, remains a matter of debate. Recently, in non‐small cell lung cancer, it was observed that E2F‐1 overexpression was associated with tumour growth, implying an ‘oncogenic’ effect. To clarify further the role of E2F‐1 in carcinogenesis, the investigation was expanded in four of the most common human malignancies by examining its expression status and putative impact on tumour kinetics. These issues were addressed by immunohistochemical and molecular means in 52 breast carcinomas, 42 prostate adenocarcinomas, 58 colon adenocarcinomas, and 77 superficial bladder transitional cell carcinomas (TCCs). The following results were found: (i) in breast carcinomas, E2F‐1 expression correlated with proliferation (p < 0.001) and growth index (p = 0.001); (ii) in prostate adenocarcinomas, absence of E2F‐1 was noted, in contrast to its expression in normal and hyperplastic glands; (iii) in colon adenocarcinomas, E2F‐1 expression was inversely related to growth index (p = 0.001), being expressed in lesions with increased apoptosis (p = 0.001) and low proliferation (p < 0.001); and (iv) in superficial TCCs, E2F‐1 expression correlated with proliferation (p = 0.002). Taken together, these results suggest that E2F‐1 has a growth‐promoting effect in breast carcinomas and superficial TCC, whereas the opposite seems to be the case for colon and prostate cancer. To interpret the above findings, the status of the pRb and p53 tumour suppressor pathways, which are known to affect E2F‐1 activity, was further investigated. The results suggest that the actions of E2F‐1 are mainly dependent on the functionality of these pathways. Nevertheless, the data also imply that p53‐independent pathways may play a nodal role in the function of E2F‐1 in colon cancer. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Rheology of co‐continuous phase in physical thermoplastic elastomers
Authors: Barzegari Mohammad R , Yousefi Ali A , Zeynali Mohammad E , Rabii Ahmad , Rodrigue Denis 
Published: June 2004

AbstractNowadays, chemical and physical thermoplastic elastomers have found many applications in different industries. Compatibilizer and co‐continuous composition are among the important factors which control the optimum properties of a number of physical blends. Morphology, mechanical and rheological properties of various blends of polystyrene (PS) and polybutadiene were investigated. The results show that the co‐continuous composition for these blends is located in‐between 24 and 35 wt% of PS. These blends show a negative deviation from the viscosity logarithmic additivity rule. This observation suggests an improvement in the interactions between the phases in co‐continuous composition. Rheological and mechanical properties were used in determination of the co‐continuous phase. Copyright © 2004 Society of Chemical Industry
UDP‐Glucose pyrophosphorylase is upregulated in carriers of the porcine RN− mutation in the AMP‐activated protein kinase
Authors: Hedegaard Jakob , Horn Per , Lametsch René , Søndergaard Møller Hanne , Roepstorff Peter , Bendixen Christian , Bendixen Emøke 
Published: June 2004

AbstractThe AMP‐activated protein kinase (AMPK) plays a key role in the regulation of energy metabolism in eukaryotic cells acting as a metabolic sensor. In its activated form AMPK inhibits ATP consuming pathways and stimulates ATP generating pathways. A dominant mutation, denoted RN−, in the porcine PRKAG3 gene, encoding the regulatory γ3 subunit of AMPK, results in hyperaccumulation of glycogen in glycolytic skeletal muscle cells. To study the effects of this mutation on protein expression patterns in skeletal muscle, comparative proteome analysis of muscle samples from 12 animals (6 rn +/rn + and 6 RN−/rn +) was performed. The major finding of the proteome analysis was that the key enzyme in the synthesis of glycogen, UDP‐glucose pyrophosphorylase, was significantly up‐regulated in RN− carriers. This observation was subsequently supported by studies of enzyme activity and Northern blot analysis. Furthermore, the expression patterns of enzymes related to glycolysis and the citric acid cycle were also affected. Our data suggests that hyperaccumulation of glycogen mediated by the RN− mutation is due to an increased synthesis of glycogen.
The identification of Dictyostelium phosphoproteins altered in response to the activation of RasG
Authors: Secko David M. , Insall Robert H. , Spiegelman George B. , Weeks Gerry 
Published: June 2004

AbstractDictyostelium RasG has been implicated in the regulation of a variety of cellular processes, including the initiation of development, cell movement, and cytokinesis, but the molecular components of the signaling pathways involved are largely unknown. We used a tetracycline‐regulated protein expression system to study the effect of activated RasG, RasG(G12T), expression on the phosphorylation state of Dictyostelium proteins. Over 70 vegetative phosphoprotein components were resolved by two‐dimensional (2‐D) immunoblot analysis and of these 16 phosphothreonine and three phosphotyrosine protein components were found to reproducibly change upon RasG(G12T) expression. Thirteen of these were recovered from 2‐D gels and identified by mass spectrometry of in‐gel tryptic digestions. The proteins identified include the signaling proteins RasGEF‐R and protein kinase B, the adhesion protein DdCAD‐1, the cytoskeletal protein actin, the mitochondrial division protein FtsZA, and proteins involved in translation and metabolism. In addition to the direct demonstration of the phosphorylation of putative downstream targets of RasG activation, these findings reveal previously undetected phosphorylation of several proteins.
Cystatin C as a potential cerebrospinal fluid marker for the diagnosis of Creutzfeldt‐Jakob disease
Authors: Sanchez Jean‐Charles , Guillaume Elisabeth , Lescuyer Pierre , Allard Laure , Carrette Odile , Scherl Alex , Burgess Jennifer , Corthals Garry L. , Burkhard Pierre R. , Hochstrasser Denis F. 
Published: June 2004

AbstractThe definite diagnosis of Creutzfeldt‐Jakob disease (CJD), the most common form of human prion diseases, relies upon neuropathological data usually obtained at autopsy. In living patients, the diagnosis, based on suggestive clinical features and EEG abnormalities, can be aided by the detection of altered levels of isoforms of the 14‐3‐3 protein in the cerebrospinal fluid (CSF). However, the validity of this test has been recently challenged and the search for other, more reliable biomarkers for CJD remains highly desirable. The present study describes the identification of a new potential surrogate marker in the CSF of CJD‐affected patients. A preliminary study employing surface‐enhanced laser desorption/ionization‐time of flight (SELDI‐TOF) technology highlighted a protein at 13.4 kDa in a small group (n = 8) of CJD‐affected patients. Further analysis aimed at identifying this protein using cationic exchange chromatography, sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE), and liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) revealed it to be cystatin C. Additional immunoblot assays confirmed that the level of cystatin C was significantly increased (p ≤ 0.05) in all tested samples (n = 8). We conclude that the analysis of cystatin C levels in CSF could be useful as a pre‐mortem indicator of the disease.
Differential proteome analysis and mass spectrometric characterization of germ line development‐related proteins ofCaenorhabditis elegans
Authors: Bantscheff Marcus , Ringel Bruno , Madi András , Schnabel Ralf , Glocker Michael O. , Thiesen Hans‐Jürgen 
Published: June 2004

AbstractProteome maps and differences of protein patterns of the synchronized larval stage L4 of the temperature‐sensitiveCaenorhabditis elegans (C. elegans)glp‐1 mutant (e2144ts) were investigated after cultivation at 15°C (developing a normal phenotype) or 25°C (developing a mutated phenotype) by two‐dimensional gel electrophoresis (2‐DE) and matrix‐assisted laser desorption/ionization (MALDI)‐mass spectrometry. From the 183 identified protein spots six proteins were found differently expressed. The Vit‐6 vitellogenin (CE28594), the hypothetical 17.2 protein (CE25224), the hypothetical 17.4 protein (CE16999), and the heat shock protein 16 kDa (CE14249) were more abundant when growing worm cultures at 25°C. By contrast, the nucleoside diphosphate kinase (CE09650) was found increased at 15°C. Most notably, the eukariotic initiation factor 5A‐1 (CE00503), highly abundant at 15°C, was not present in cultures grown at 25°C. Its absence at 25°C can not be attributed to lack of the enzymatic machinery that is necessary for hypusinylation. Instead, a direct downstream effect of the lack of functionality of GLP‐1 may cause the expression of this protein. The yolk proteins 115 kDa and 88 kDa were attributed by mass spectrometric protein structure analysis asC‐terminal andN‐terminal fragments of the Vit‐6 vitellogin protein (CE28594), respectively. The cleavage site between both derivatives was located between R764 and A768. A conflict in the database sequences at amino acid positions 1622 and 1623 of vitellogenin‐6 was solved by mass spectrometric sequence analysis. The combination of 2‐DE with mass spectrometry enabled the identification of mutation‐associated differences on somatic gonadal cell and germ line cell development‐associated proteins.
Some physical properties of polyorganosiloxanes. II. Nonlinear and irregular polyelementorganosiloxanes
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 irregular and nonlinear polydimethylsiloxane elastomers have been studied. The effects of chemical structure, vulcanization, and filler on the glass transition, melting, and crystallization have been investigated. The crystallization kinetics has been studied in detail.
Crystallization and polymerization of 6‐aminocaproic acid as simultaneous processes
Authors: Macchi E. M. 
Published: June 2004

AbstractVapor of 6‐aminocaproic acid (ACA) at a pressure of 0.12 mm Hg was observed to polymerize when placed in the presence of different types of surfaces, crystalline and amorphous, at temperatures around 170°C. Two clearly distinct stages of the process could be detected. The first was an induction period, during which the polymer phase must be nucleated. The length of this nucleation stage depended on factors not well understood. In the second stage, polymer was produced at a constant rate which seemed to be related to the vapor pressure of ACA. The polymer produced consisted of the characteristic radiating arrays of ribbonlike crystals known as spherulites. The spherulites, in turn, were made up of primary and secondary lamellae about 90 Å thick. Electron diffraction studies showed that the polymer chains were folded within the lamellae. Further it was proved by chemical and crystallographic arguments that adsorption and polymerization should be simultaneous processes.
Effect of radical scavenger on initiation efficiency
Authors: Ito Katsukiyo 
Published: June 2004

AbstractIn order to analyze the effect of the scavenger on initiator efficiency f or ratio of combination between two radicals (1 − f), an equation was derived by solving the modified Smoluchowski equation under the boundary condition based on the law of conservation of mass. At time t approaching infinity in a stationary state, this equation becomes: f = {D + a(Dk[S])1/2}/{ak0 + D + a(Dk[S])1/2}, where D is the sum of the diffusion constants of two radicals, a is the diameter of the radical particle, k0 is a specific rate of recombination in the cage between two radicals, k is the rate constant of reaction between the radical and the scavenger as a pair, and [S] is the scavenger concentration. When ak0 ≪ D and k[S] is small, this equation approximates the previously derived Wijsman's equation. An equation of the same type as Noyes' equation is also derived from this equation, when [S] = 0. By using the equations derived in this paper, the effect of α,α′‐diphenyl‐β‐picrylhydrazyl on the ratio of recombination of the (CH3)‐(CN)C* radical and the effect of monomer on the initiation efficiency are satisfactorily explained.
Anionic polymerization of vinyl monomers with xanthates
Authors: Yamaguchi Koichi , Sonoda Osamu , Minoura Yuji 
Published: June 2004

AbstractThe polymerization of vinyl monomers with various xanthates (potassium tert‐butylxanthate, potassium benzylxanthate, zinc n‐butylxanthate, etc.) were carried out at 0°C in dimethylformamide. N‐Phenylmaleimide, acrylonitrile, methyl vinyl ketone, and methyl methacrylate were found to undergo polymerization with potassium tert‐butylxanthate; however, styrene, methyl acrylate, and acrylamide were not polymerized with this xanthate. In the anionic polymerization of methyl vinyl ketone with potassium tert‐butylxanthate, the rate of the polymerization was found to be proportional to the catalyst concentration and to the square of the monomer concentration. The activation energy of methyl vinyl ketone polymerization was 2.9 kcal/mole. In the polymerization, the order of monomer reactivity was as follows: N‐phenylmaleimide > methyl vinyl ketone > acrylonitrile > methyl methacrylate. The initiation ability of xanthates increased with increasing basicity of the alkoxide group and with decreasing electronegativity of the metal ion in the series, lithium, sodium, and potassium tert‐butylxanthate. The relative effects of the aprotic polar solvents on the reactivity of potassium tert‐butylxanthate was also determined as follows: diethylene glycol dimethyl ether > dimethylsulfoxide > hexamethylphosphoramide > dimethylformamide > tetrahydrofuran (for methyl vinyl ketone); dimethyl sulfoxide > hexamethylphosphoramide > dimethylformamide ≅ diethylene glycol dimethyl ether (for acrylonitrile).
Syntheses of vinyl polymers containing the N‐phenothiazinyl group in the side chain
Authors: Kamogawa Hiroyoshi 
Published: June 2004

AbstractFour kinds of vinyl polymers containing N‐substituted phenothiazinyl groups in side chains were obtained by syntheses of the respective monomers and subsequent polymerizations. Thus, N‐acrylamidomethylphenothiazine, N‐(N‐acrylamidomethyl)carbamoylethyl phenothiazine, β‐(N‐phenothiazinyl)ethyl acrylate and methacrylate, and β‐(N‐phenothiazinyl)ethyl vinyl ether were synthesized. It was found that all monomers except the last monomer can be polymerized with typical free‐radical initiators such as α,α′‐azobisisobutyronitrile to afford stable soluble polymers with electron‐donating characteristics, presumably due to the absence of a hydrogen atom at the site of the nitrogen atom of the phenothiazinyl group. The last monomer was found to be susceptible to typical cationic initiators such as boron trifluoride etherate to afford a stable soluble polymer also with the electron‐donating characteristic.
Polymerizable siloxane precursors having in‐chain perfluoroalkyl groups
Authors: Patterson William J. , Morris Donald E. 
Published: June 2004

AbstractThe synthesis and polymerization of several silphenylene siloxane polymer precursors containing a perfluoroalkylsegment in the backbone was carried out. The molecular weight characteristics of polymers from 1,3‐bis[p(‐hydroxydimethylsilyl)phenyl]hexafluoropropane and 1,3‐bis[p(‐dimethylaminodimethylsilyl)phenyl]hexafluoropropane were studied as a function of polymerization conditions. Polymers containing the dodecafluorohexane chain segment were also prepared. Polymers having inherent viscosities of 0.55 to 0.9 were obtained. The polymers crosslinked at room temperature to thermoset elastomers which were characterized by improved thermal and oxidative stability over dimethylsilicones. Room temperature swelling of the experimental polymers hydrocarbon solvents was also much lower than that of dimethylsilicones. The polymers containing the (CF2)3 and (CF2)6 linkages had glass transition points of −12°C and −34°C, respectively.
Reactivities of cis‐ and trans‐3‐substituted acrylic acids on copolymerization with acrylamide
Authors: Matsuo Keizo , Machida Seishi 
Published: June 2004

AbstractSeveral pairs of cis‐ and trans‐3‐substituted acrylic acids (3SAA) were copolymerized with acrylamide in order to determine the major factors affecting the relative reactivities of geometrical isomers of 1,2‐disubstituted ethylenes (1,2‐DE). The results were that the relative reactivity of cis isomer is larger than that of trans isomer when one substituent is electron‐withdrawing and the other is electron‐donating. The trans isomer is more reactive than the cis isomer when both substituents are electron‐withdrawing. A new method of reactivity comparison of cis‐ and trans‐1,2‐DE is proposed in regard to the inductive substituent constant.
Vinyl polymerization. 275. Polymerization of vinyl monomers photosensitized by tetramethyltetrazene
Authors: Sugiyama Kazuo , Nakaya Tadao , Imoto Minoru 
Published: June 2004

AbstractA study of the photopolymerization of vinyl monomers in the presence of tetramethyltetrazene (TMT) was made. TMT was found to act as an effective sensitizer. In the photopolymerization of vinyl monomers such as methyl methacrylate or styrene the rate of polymerization was expressed by the equation: Rp = k[TMT]1/2[monomer]. The chain‐transfer constant of TMT under ultraviolet irradiation was estimated to be 3.8 × 10−2 for the above monomers. A linear correlation was found to exist between the reactivity of dimethylamino radical toward the vinyl monomers and e values for the corresponding monomers.