bluuebunny/crossref_metadata_2025_split huggingface dataset:
Environment for multiprocessor simulator development
Authors: Wakabayashi Masaki , Amano Hideharu 
Published: April 2003

AbstractTo develop multiprocessor systems for continuing the precipitous increase in performance seen in recent years, it is important to include performance prediction at a preimplementation stage. Since software simulation, which is one such performance prediction technique, has a high degree of flexibility, it is used in diverse situations. To simulate a multiprocessor system, a simulator is implemented for a specific architecture. However, this method has accompanying implementation costs for building a simulator for each different target architecture. In this paper, the authors propose the multiprocessor simulator library ISIS as a multiprocessor simulator construction support system. ISIS is a collection of multiprocessor system internal function block simulators. Multiprocessor simulators having any kind of architecture can be constructed by combining function block simulators. Compared with conventional techniques, implementation costs can be reduced without directly impairing simulator runtime costs. Several multiprocessor simulators were implemented by using ISIS, and their execution speeds and implementation costs were evaluated. Sufficient runtime speeds were obtained for practical uses at extremely low implementation costs. ISIS has actually been used in research for on‐chip multiprocessor cache systems, and various kinds of knowledge have been obtained from the evaluation results of that research. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(10): 74–84, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10122
Two novel in vitro human hepatoblastoma models, HepU1 and HepU2, are highly characteristic of fetal–embryonal differentiation in hepatoblastoma
Authors: Scheil Stefanie , Hagen Silvia , Brüderlein Silke , Leuschner Ivo , Behnisch Wolfgang , Möller Peter 
Published: April 2003

AbstractUsing comparative genomic hybridization (CGH), we present a genome‐wide screening of a mixed mesenchymal–epithelial hepatoblastoma, its recurrence and 2 novel hepatoblastoma cell lines raised from the ascites, 18 (HepU1) and 23 (HepU2) months after diagnosis of a hepatoblastoma in a 35‐month‐old boy. Both cell lines were also characterized by GTG‐banding, multicolor‐fluorescence in situ hybridization (M‐FISH) and multicolor banding (M‐Band). On the basis of CGH, we compared the cytogenetics of histologically different tumor areas of the parental tumor and its recurrence with the hepatoblastoma cell lines. We found different CGH profiles in the parental tumor rev ish enh(1q31–q32,8p,12,17,20,X), dim(4q34–q35,18q23)[cp] and its recurrence rev ish enh(8q24,17,Xq26–q28), dim(7q11.2–q21,13q34)[cp]. Although both epithelial cell lines were obtained at different times and the clonal ancestor of HepU2 had been exposed to a higher cumulative dose of chemotherapy, HepU1 and HepU2 have an identical karyotype: 48‐56,XY,+Y,dup(2)(q32–q34),t(3;4)(q21;q34),+8,+12,+13, +17,+t(18;19)(q21;q?),+20[cp] and identical CGH profiles: rev ish enh(2q24–q33,8,12,13q,17,20), dim(4q34–q35,18q22–q23). In common with previously described hepatoblastoma cell lines, HepU1 and HepU2 demonstrate a gain of chromosome 20. The in situ aberrations most closely resembling that of HepU1 and HepU2 were found in areas of fetal–embryonal differentiation of the primary tumor. Interestingly, both cell lines mimic this histology in their three‐dimensional growth pattern in vitro. HepU1 and HepU2 are thus cytogenetically and phenotypically highly characteristic of fetal–embryonal hepatoblastoma. © 2003 Wiley‐Liss, Inc.
Urokinase‐mediated posttranscriptional regulation of urokinase‐receptor expression in non small cell lung carcinoma
Authors: Montuori Nunzia , Mattiello Amalia , Mancini Alessandro , Taglialatela Paola , Caputi Mario , Rossi Guido , Ragno Pia 
Published: April 2003

AbstractThe urokinase‐type plasminogen activator (uPA) and its cellular receptor (uPAR) are involved in the proteolytic cascade required for tumor cell dissemination and metastasis, and are highly expressed in many human tumors. We have recently reported that uPA, independently of its enzymatic activity, is able to increase the expression of its own receptor in uPAR‐transfected kidney cells at a posttranscriptional level. In fact, uPA, upon binding uPAR, modulates the activity and/or the level of a mRNA‐stabilizing factor that binds the coding region of uPAR‐mRNA. We now investigate the relevance of uPA‐mediated posttranscriptional regulation of uPAR expression in non small cell lung carcinoma (NSCLC), in which the up‐regulation of uPAR expression is a prognostic marker. We show that uPA is able to increase uPAR expression, both at protein and mRNA levels, in primary cell cultures obtained from tumor and adjacent normal lung tissues of patients affected by NSCLC, thus suggesting that the enzyme can exert its effect in lung cells. We investigated the relationship among the levels of uPA, uPAR and uPAR‐mRNA binding protein(s) in NSCLC. Lung tissue analysis of 35 NSCLC patients shows an increase of both uPA and uPAR in tumor tissues, as compared to adjacent normal tissues, in 27 patients (77%); 19 of these 27 patients also show a parallel increase of the level and/or binding activity of a cellular protein capable of binding the coding region of uPAR‐mRNA. Therefore, in tumor tissues, a strong correlation is observed among these 3 parameters, uPA, uPAR and the level and/or the activity of a uPAR‐mRNA binding protein. We then suggest that uPA regulates uPAR expression in NSCLC at a posttranscriptional level by increasing uPAR‐stability through a cellular factor that binds the coding region of uPAR‐mRNA. © 2003 Wiley‐Liss, Inc.
Oxidative neurotoxicity in rat cerebral cortex neurons: Synergistic effects of H2O2 and NO on apoptosis involving activation of p38 mitogen‐activated protein kinase and caspase‐3
Authors: Wang Jiz‐Yuh , Shum Andrew Y. C. , Ho Yi‐Jung , Wang Jia‐Yi 
Published: April 2003

AbstractOxidative stress in the brain has been increasingly associated with the development of numerous human neurological diseases. Microglia, activated upon neuronal injury or inflammatory stimulation, are known to release superoxide anion (·O), hydrogen peroxide (H2O2), and nitric oxide (NO), thereby further contributing to oxidative neurotoxicity. The reaction of NO and ·O, forming the toxic peroxynitrite (ONOO−), has been proposed to play a pathogenic role in neuronal injury. However, the interactions between H2O2 and NO during oxidative stress, which may promote or diminish cell death, is less clear. In this study, we explored oxidative neurotoxicity induced by H2O2 plus NO in primary cultures of rat cerebral cortex neurons. As the mechanisms may involve reactions between H2O2 and NO, we monitored the production of ONOO−and reactive oxygen species (ROS) throughout the experiments. Results indicated that the NO donor S‐nitroso‐N‐acetyl‐D, L‐penicillamine (SNAP) and H2O2 by themselves elicited neuronal death in a concentration‐ and time‐dependent manner. Sublytic concentrations of H2O2 plus SNAP were sufficient to induce neuronal apoptosis as determined by DNA laddering and fluorescent staining of apoptotic nuclei. Transient ONOO−increase was accompanied by rapid H2O2 decay and NO production, whereas ROS slowly decreased following treatment. Furthermore, p38 mitogen‐activated protein kinase (MAPK) activation and the cleavage of caspase‐3 were observed. Conversely, inhibition of p38 MAPK and caspase‐3 significantly reduced apoptotic death induced by H2O2 plus SNAP. These data suggest that H2O2 and NO act synergistically to induce neuronal death through apoptosis in which activation of p38 MAPK and caspase‐3 is involved. © 2003 Wiley‐Liss, Inc.
Age‐related changes in neuronal glucose uptake in response to glutamate and β‐amyloid
Authors: Patel Jigisha R. , Brewer Gregory J. 
Published: April 2003

AbstractEnergy supplies that may decline with age are crucial for cells to maintain ionic homeostasis and prevent neuron death. We examined baseline glucose transporter expression and rate of glucose uptake in cultured hippocampal neurons from embryonic, middle‐age (12‐month‐old), and old (24‐month‐old) rats and exposed the neurons to glutamate, β‐amyloid, and mitochondrial inhibitors. Without stress, the rate of glucose uptake was similar in middle‐age and old neurons, and the rate of glucose uptake in embryonic neurons was threefold greater than that in middle‐age and old neurons. Glucose uptake increased in the presence of mitochondrial inhibitors (FCCP and oligomycin) for embryonic and middle‐age neurons. The old neurons failed to increase glucose uptake. In the presence of glutamate, FCCP, and oligomycin, embryonic neurons showed a decrease in glucose uptake and the middle‐age and old neurons showed no change in glucose uptake. Middle‐age neurons took up significantly more glucose than old neurons when under mitochondrial and glutamate stress. In the presence of β‐amyloid, only embryonic neurons increased glucose uptake; middle‐age and old neurons did not. Fluorescence imaging of immunoreactive glut3 in response to β‐amyloid demonstrated a 16–49% increase in glut3 immunoreactivity at the plasma membrane for the three ages. The results suggest that old neurons were not able to upregulate glucose uptake to ensure cell survival. Neuron aging does not indicate a defect in normal glut3 function; rather, our results suggest that mechanisms regulating glucose uptake under stress fail to react in time to ensure cell survival. © 2003 Wiley‐Liss, Inc.
Über die konstitution der harnstoff‐ resp. thioharnstoff‐ formaldehydkondensate. 405. mitteilung über makromolekulare verbindungen
Authors: Staudinger Hermann , Wagner Kuno 
Published: April 2003

AbstractDie bei der Kondensation von Harnstoff resp. Thioharnstoff mit Formaldehyd sich bildenden hochviskosen Lösungen sind nicht kolloid, sondern sie enthalten kleine dialysierbare Moleküle. Die hohe Viskosität beruht auf einer Assoziation durch Hydroxylgruppen. Für die unlöslichen pulvrigen Kondensationsprodukte wurden Lösungsmittel gefunden: für die des Thioharnstoff‐Formaldehyds Dimethylformamid und Caprolactam, für die Harnstoffprodukte wäßrige Lösungen von Lithiumbromid, Lithumjodid und Magnesiumperchlorat. In diesen Kondensationsprodukten sind 4–5 Thioharnstoff‐ resp. 6–8 Harnstoffreste gebunden, wie durch kryoskopische und Endgruppenmolekulargewichtsbestimmungen nachgewiesen wurde. Die glasartigen Kondensationsprodukte, die sich mit einem Überschuß von Formaldehyd bilden, sind vollkommen unlöslich; deshalb läßt sich über ihr Molekulargewicht nicht aussagen. Es liegen hier wahrschienlich stark vernetzte Produkete vor. Sämtliche höhermolekularen Kondensationsprodukte sind untrennbare Gemische, aber nicht von polymereinheitlichen Kondensation, sondern von Kondensaten verschiedenen Baues.
Über die Beziehung zwischen Viskositätszahl und Molekulargewicht bei Polystyrolen im hemikolloiden bis makromolekularen Bereich
Authors: Marzolph von. H. , Schulz G. V. 
Published: April 2003

AbstractAn fraktionierten und besonders gereinigten Polystyrolen werden kryoskopische Molekulargewichtsbestimmungen im Molekulargewichtsbereich von 1 000 bis 40 000 duchargeführt. Die Meßergebnisse werden durch andere Methoden nachkontrolliert und bestätigt. Von denselben Präparaten wird die Viskositätszahl bestimmt. Es zeigte sich, daß diese unabhängig von dem Mechanismus der Polymerisation (Radikalketten oder Ionenketten) ist. Die log Zη‐log M‐Funktion verläuft entgegen der voraussage der bisher aufgestellten Theorien im untersuchten Bereich flacher als bei hohen Polymerisationsgraden (vgl. Abb.3).
Nachweis und chemische umsetzungen von endgruppen in polystyrolen
Authors: Kern Von W. , Achon M. A. , Sehulz R. 
Published: April 2003

AbstractBei der Lösungspolymerisation van Styrol mit dem Eisen‐Redox‐System Brombenzoylperoxyd/Fe/Benzoin werden Brombenzoesäure‐Ester‐Gruppen in das Makromolekül eingebaut; diese lassen sich quantitativ verseifcn. Dabei entstehen Polymere mit alkoholischen Endgruppen; diese können mit Dichlorphenylisocyanat umgesetzt und quantitativ bestimmt werden. Mit Brombenzopersäure/Fe/Benzoin erhaltene Polystyrole enthalten keine Brombenzoesäure‐Esterendgruppen sondern alkoholische Endgruppen, die ebenfalls mit Dichlorphenylisocyanat umgesetzt wurden. Die alkoholischen und esterartjgen Endgruppen lassen sich ultrarotspektroskopisch nachweisen.
Beitrag zur konzentrationsabhängigkeit der viskositätszahl sehr verdünnter polyvinylchloridlösungen
Authors: Cernia Von Enrico , Ciampa Giuseppe 
Published: April 2003

AbstractBei einigen Polyvinylchloridproben wurde die Konzentrationsabhängigkeit von ηsp/c im Bereich extrem verdünter Lösungen in Cyclohexanon je nach dem Verzweigungsgrad verschieden gefunden.
Microstructure of copolymer and catalyst species in the copolymerization of 3,3‐bis (chloromethyl) oxacyclobutane and β‐propiolactone with boron trifluoride etherate
Authors: Tada Koichi , Saegusa Takeo , Furukawa Junji 
Published: April 2003

AbstractIn the studies of the BF3·Et2O catalyst copolymerization of 3,3‐bis(chlormethyl)oxacyclobutane and β‐propiolactone, there have been obtained several observations suggesting that a reaction between the BF3·Et2O catalyst and the monomers occurs in the course of copolymerization to produce different catalyst species, which also induce copolymerizations of different character. Consequently there exist at least two kinds of catalyst species in this copolymerization system. Therefore, the copolymerization parameters obtained by a conventional technique are merely apparent and are not reasonably referred to in the quantitative discussion of monomer reactivity and of monomer unit distribution in the produced copolymer. The (deviation of the monomer unit distribution from the one calculated by statistical treatment has been ascribed to the multiplicity of catalyst species.)
Viscosity‐molecular weight relation and unperturbed dimensions of polyethylene terephthalate
Authors: Wallach M. L. 
Published: April 2003

AbstractA series of polyethylene terephthalate resins were characterized for molecular weight by light scattering measurements in trifluoracetic acid (TFA) solution and for intrinsic viscosity in TFA and in a mixture of tetrachloroethane (TCE)/phenol. The following viscositymolecular weight relations were established:

The unperturbed dimensions (〈r02〉/M)1/2 were derived by the method of KURATA‐STOCK‐MAYER (0.985 a. u.) and STOCKMAYER‐FIXMAN (0.966 a.u.). The steric factor (1.4) is similar to that of other polymers with p‐phenylene groups in their chain backbone. The results are compared to previous findings based on end group, osmometric, and cryoscopic data.
Dilute solution properties of poly(vinyl acetate). I. Molecular weight dependence of the limiting viscosity number in a few solvents
Authors: Ueda Minoru , Kajitani Koichi 
Published: April 2003

AbstractRelationships between limiting viscosity number and molecular weight are reported for the systems poly(vinyl acetate) in acetone at 6 and 30°C, in chloroform at 6°C, and in the Θ‐solvent methanol at 6°C, in the molecular weight range from 3.5·103 to 1.5·106 using 24 narrow distribution fractions. Plots of [η] vs. M on a double logarithmic graph indicate that K and v in the KUHN‐HOUWINK‐SAKURADA equation are not constant for the good solvent systems. Neither the FLORY‐FOX‐SCHAEFGEN plot nor the STOCKMAYER‐FIXMAN plot gives straight lines. A new empirical relationship is proposed for [η] vs. M.
Cyclopolycondensations. IX. Syntheses of fully aromatic polyetherpoly‐1.2.4‐oxadiazoles
Authors: Dokoshi Noriaki , Bamba Yasuo , Kurihara Masaru , Yoda Naoya 
Published: April 2003

AbstractThe low temperature solution polymerization of aromatic bisamidoximes and aromatic dicarboxylic acid chlorides was studied. Fully aromatic polyetherpoly‐O‐acylamidoximes of high molecular weight were obtained, which were transformed into thermally Stable aromatic polyetherpoly‐1.2.4‐oxadiazoles by thermal cyclodehydration. As a new monomer, diphenylether‐4.4′‐dicarboxylic acid chloride was, prepared. The solubility of copolymers of poly‐O‐acylamidoximes with the ether linkages along the polymer chain was found to be remarkably improved compared with the corresponding, aromatic poly‐O‐acylamidoximes. The conditions of the cyclopolycondensation reaction and the characterizations of the resulting polymers are described.
Dilute solution properties of poly(vinyl acetate). II. Experimental tests of theories for the excluded volume effect in chain polymers in therms of the limiting viscosity number‐molecular weight relationship
Authors: Ueda Minoru , Kajitani Koichi 
Published: April 2003

AbstractViscosimetric tests are applied to examine the validity of the existing equations for the excluded volume in terms of experimental data. The PTITSYN equation is adequate to describe the excluded volume effect if combined with a semi‐empirical relation between two expansion factors α and αη for the end‐to‐end distance and the hydrodynamic radius, respectively, i. e., α2.43 = αη3. This combination is found to be equivalent with:

for 0.330ċBċA−3M1/2 = Z > 0.03. The temperature dependence of K for the system PVAc/methanol is −2.7ċ10−3/°C. The unperturbed dimension varies slightly with the chemical structure of the solvent. The parameter B is directly proportional to (1−Θ/T), from which we obtain B0 = 6.73ċ10−27 Up to (Θ + 35)°C. A comparison of B with A2 for the system, PVAc/acetone shows the consistency of interchain and intrachain interactions. The maximum exponent ν in [η] = KMν is predicted to be 0.9.
Pressure effect on the radiation‐induced solid state polymerization of β‐propiolactone
Authors: Tabata Yoneho , Shu So‐Sei , Oshima Keichi 
Published: April 2003

AbstractThe effect of pressure on the radiation‐induced solid state polymerization of β‐propiolactone has been investigated in the range of 1 to 5000 atm over a temperature region of −196 to −78°C. Rates of polymerization, viscosities, melting points and infrared spectra have been measured.It was found that the rate of polymerization is accelerated by pressure at temperatures below −98°C, and that the activation energies change for polymerizations at 1 and 5000 atm from 0.01 kcal/mole to 0.18 kcal/mole.The pressure effect was discussed from the point of initiation, propagation and termination reactions, taking the effect of additives on the polymerization into consideration.It may be concluded from the study that the effect of pressure on the propagation reaction is most important and the pressure effect is not only due to the change of the activation enthalpy but also the change of the activation entropy.
On the unperturbed dimensions of cis‐1.4 polybutadiene
Authors: Allegra G. 
Published: April 2003

AbstractContrary to the usual procedure which considers only the local conformations of minimum energy, the mean‐square end‐to‐end distance of cis‐1.4 polybutadiene is recalculated taking into account the whole continuum of conformational states; elastic strain on the bond angles has been also allowed for, but only the values which minimize the conformational energy have been retained, for every set of rotation angles. Such a calculation has been carried out because in the polymer under consideration the broadness of the potential minima and the low energy barriers should lower the degree of accuracy of the results based on the equilibrium states calculations.As a matter of fact, the results show drastic differences with respect to those obtained by traditional procedures6,7, with analogous values of the potential energy parameters. Using different values of the zero‐strain angle, agreement with the experimental figures of r̄/n at 20°C1‐3 is obtained for positive values of the energy difference between the gauche and the trans state on the ‐ [CH2CH2]‐ bonds. The corresponding calculated figures of dln r̄/dT are very close to zero; in this case, comparison with experiment is complicated by the disagreement between the oppositely signed results given by stresstemperature measurements4,5, on one hand, and by viscosity methods2, on the other hand.
Research in the field of terpolymers. I. Copolymerization of acrylonitrile/methaerylic acid/methyl methacrylate
Authors: Simionescu C. , Asandei N. , Liga A. 
Published: April 2003

AbstractIt is known that copolymerization reactions permit the extension of the scope of monomer utilizations, and especially, the controlled modification of the physico‐chemical and mechanical properties of polymers. Many types of elastomers, plastics and synthetic fibers are synthetized at present on the basis of such a reaction.In the last years the field of synthetic fibres has acquired an ever wider utilization together with other groups of spinning polymers as, for instance, the polyamides and polyesters, the acrylic and vinylic copolymers where acrylonitrile is the main component, thanks to the properties it imparts on the polymers.The kinetics of the copolymerization of the ternary system acrylonitrile/methacrylic acid/methyl methacrylate is studied. The polymerization was carried out in inert medium and homogeneous phase (solvent: ethylene glycole carbonate) using lauryl peroxide as initiator.The authors investigated the variation of copolymer composition as compared to the initial monomer ratios at different conversions and depending on polymerization conditions.For the calculation of the composition at a high degree of conversion the monomer reactivities were determined at 70°C by using FINEMAN‐ROSS, MAYO‐LEWIS, and JOSHI‐KAPUR, relations. Some discrepancies in the results obtained by each of these methods are discussed.
Polymerization of epoxyorganosilanes
Authors: Tsuruta Teiji , Inoue Shohei , Koenuma Hideomi 
Published: April 2003

AbstractPolymerization of three epoxy compounds with a trimethylsilyl group, i.e., epoxyethyltrimethylsilane (I), (3.4‐epoxybutyl) trimethylsilane (II) and (2.3‐epoxypropoxy) trimethylsilane (III) was attempted with organometallic compounds as catalyst. Polymers obtained from I by any of the catalysts examined were of low molecular weight. II and III, on the other hand, yielded high polymers and showed similar polymerizability to other alkylene oxides or glycidyl ethers. Results were discussed in relation to the effects of the trimethylsilyl group on the polymerization. Polyglycidol derived from the polymer of III by hydrolysis was of much higher molecular weight than that by direct polymerization of glycidol with an onganometallic catalyst.
Thermodynamics of addition polymerisation. Part 3. The heat capacity, entropy, enthalpy and free energy of a random ethylene/propylene copolymer
Authors: Melia T. P. , Clegg G. A. , Tyson A. 
Published: April 2003

AbstractAn adiabatic, vacuum calorimeter has been used to measure the heat capacity of a random ethylene/propylene copolymer, containing 31 mole per cent propylene, from 80 to 320°K. An estimate has been made of heat capacity values below 80°K. Entropy, enthalpy and free energy values have been derived and are listed at ten degree intervals. The difference (1.2 cal deg−1 mole repeat unit−1) between the observed entropy (15.1 ± 0.2 cal deg−1 mole repeat unit−1) and that calculated from previously published data for polyethylene and polypropylene (16.3 ± 0.2 cal deg−1 mole repeat unit−1) is consistent with the random nature of the arrangement of co‐monomer units along the chain, which would be expected to give rise to a residual entropy of 1.23 cal deg−1 mole repeat unit−1. The entropy of polymerisation of the gaseous co‐monomers at 1 atmosphere pressure and 298.16°K to amorphous polymer, ΔS, has been calculated as −41.1 ± 0.2 cal deg−1 mole repeat unit−1. The glass transition temperature of the copolymer was found to be 214 ± 2°K. The increase in heat capacity of the copolymer at the glass transition temperature, 2.6 cal deg−1 bead−1See page 94.
, is in agreement with that expected on the basis of the hole theory of melting. An approximation is made of the number of vibrating units per repeat unit at 298.16°K.