bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some aspects of the properties of nylon‐6, 6/poly(ethylene naphthalate) blends
Authors: Jung Dylan D. , Bhattacharyya Debes , Easteal Allan J. 
Published: August 2002

AbstractBlends of Nylon 66(Ny66) and polyethylene naphthalate (PEN) with 30, 50, 70 wt % Ny66, and one blend with 50% Ny66 and 3% compatibilizer, prepared by extrusion and injection molding, were investigated using 13C and 1H nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). A new band in the FTIR spectra of blends, at 1324–1329 cm−1 is interpreted as arising from partial reaction of Ny66 and PEN occurring during melt processing. However, NMR spectra show no evidence of interchange reaction between Ny66 and PEN. SEM indicates that the phase inversion point is close to equal proportions by weight of the two homopolymers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1504–1514, 2001
Development of membranes by radiation grafting of acrylamide into polyethylene films: Characterization and thermal investigations
Authors: Gupta Bhuvanesh , Anjum Nishat 
Published: August 2002

AbstractPolyethylene‐g‐polyacrylamide membranes were prepared by graft polymerization of acrylamide into polyethylene films by preirradiation technique. The characterization and thermal behavior of membranes with different degrees of grafting were evaluated by density, X‐ray diffraction, thermogravimetric analysis, and differential scanning calorimetry measurements. Grafting led to considerable changes in the structure of polyethylene membranes. The density of the polyethylene film increased wtih the increase in the degree of grafting, although the increase beyond 100% grafting was less pronounced than at lower graft levels. The heat of fusion and the crystallinity of polyethylene decreased with the increase in the degree of grafting. The decrease in crystallinity is because of the cumulative effect of the dilution of inherent crystallinity by the incorporation of amorphous polyacrylamide grafts within the noncrystalline region of polyethylene (dilution effect) and partial disruption of the crystallites (crystal defects). X‐ray diffraction measurements also revealed a decrease in the crystallinity in grafted films. Membranes behaved as a two‐component system where polyethylene and polyacrylamide components underwent independent degradation irrespective of the graft levels. In general, the thermal stability of polyethylene in membranes was markedly improved by the grafting of acrylamide monomer as evident from the initial decomposition temperature increasing from 311°C for virgin PE to 390°C in grafted membranes. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2629–2635, 2001
A new analytical method to calculate intrinsic viscosity and viscosity constants of polymer–solvent systems
Authors: Toti Udaya S. , Amur Krishna S. , Kariduraganavar Mahadevappa Y. , Manjeshwar Lata S. , Aralaguppi Mrityunjaya I. , Aminabhavi Tejraj M. 
Published: August 2002

AbstractExperimental viscosities were measured by Schott Gerate viscometer at 30 °C for polystyrene–chloroform and polycaprolactum–benzene systems. These data were analyzed by a newly developed analytical method to calculate intrinsic viscosity and viscosity constants. The analytical method was compared with the graphical as well as the least squares methods and the new analytical method is better than the graphical method because it avoids personal errors that might arise in reading the intercept and slope values from the reduced viscosity versus concentration plots. Furthermore, the analytical method is as effective as the least squares method, but provides better insights while choosing the experimental viscosity values. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 283–290, 2002
Synthesis of graft copolymers from natural rubber using cumene hydroperoxide redox initiator
Authors: Arayapranee W. , Prasassarakich P. , Rempel G. L. 
Published: August 2002

AbstractThe graft copolymerization of 50/50 (w/w) styrene/methyl methacrylate mixtures onto natural rubber seed latex were carried out by using cumene hydroperoxide/sodium formaldehyde sulfoxylate dihydrate/EDTA‐chelated Fe2+ as a redox initiator. The effects of the process factors such as the amount of initiator, emulsifier, and chain‐transfer agent; monomer‐to‐rubber ratio; and temperature on the grafting efficiency (GE) and grafting level (GL) are reported. The mechanism of graft copolymerization was investigated. The synthesized graft copolymers were purified and then characterized by proton nuclear magnetic resonance (1H‐NMR) analysis. Transmission electron microscopy (TEM) was used to study the morphology of the graft copolymers. It appears that the formation of graft copolymers occurs on the surface of the latex particles through a chain‐transfer process. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2993–3001, 2002; DOI 10.1002/app.2328
An application of three bivariate time‐varying volatility models
Authors: Vrontos I. D. , Giakoumatos S. G. , Dellaportas P. , Politis D. N. 
Published: August 2002

AbstractThe multivariate time‐varying volatility models have recently attracted a lot of attention in the statistics/econometrics community. We apply two bivariate ARCH–GARCH models and a bivariate unobserved ARCH model to a series of exchange rates, and we estimate the parameters using Bayesian inference. We compare these models using a posterior predictive model diagnostic. Copyright © 2001 John Wiley & Sons, Ltd.
New Fourier transform infrared based computational method for peptide secondary structure determination. II. Application to study of peptide fragments reproducing processing site of ocytocin–neurophysin precursor
Authors: Simonetti Mario , Di Bello Carlo 
Published: August 2002

AbstractA new method for the quantitative determination of the percentage of intramolecular H‐bonds, based on Fourier transform infrared techniques, is applied to the conformational analysis of a series of synthetic peptides spanning the processing site of the ocytocin and neurophysin precursor. Even though the method uses traditional tools such as Fourier self‐deconvolution, the Nth derivative, and curve‐fitting procedures for the analysis of the spectra, the assignment of the absorptions due to peptide groups participating into secondary structures is based on the direct observation and quantification of the isotopic effect induced on the groups participating in intramolecular H‐bonds in the presence of organic solvents. This permits the quantification of the different populations of molecules containing intramolecular H‐bonds involved in β‐turns and α‐helices. The results are consistent with those previously obtained by NMR techniques in the same solvent systems. © 2001 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 62: 109–121, 2001
Type‐specific separation of animal cells in aqueous two‐phase systems using antibody conjugates with temperature‐sensitive polymers
Authors: Kumar A. , Kamihira M. , Galaev I. Yu. , Mattiasson B. , Iijima S. 
Published: August 2002

AbstractA new type of aqueous two‐phase system (ATPS) has been developed in which a temperature‐sensitive polymer, poly‐N‐isopropylacrylamide [poly (NIPAM)] was used as a ligand carrier for the specific separation of animal cells. Monoclonal antibodies were modified with itaconic anhydride and copolymerized with N‐isopropylacrylamide, and the ligand‐conjugated carriers were added to the polyethylene glycol 8000–dextran T500 aqueous two‐phase systems. The antibody–polymer conjugates were partitioned to the top phase in the absence or presence of 0.15 M NaCl. When ligand‐conjugated carriers were used, more than 80% of the cells were specifically partitioned to the top phase in the presence of NaCl up to 0.1 M. The cells were partitioned almost completely to the bottom phase at 0.1 M NaCl or above, when no antibody–conjugate was added in the ATPS. As a model system, CD34‐positive human acute myeloid leukemia cells (KG‐1) were specifically separated from human T lymphoma cells (Jurkat) by applying anti‐CD34 conjugated with poly‐N‐isopropylacrylamide in the aqueous two‐phase system. By the temperature‐induced precipitation of the polymer, about 90% of the antibody–polymer conjugates were recovered from the top phase, which gave approximately 75% cell separating efficiency in the next cycle of reuse. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 75: 570–580, 2001.
Enzymatic hydrolysis of nitrides by an engineered nitrile hydratase (Papain Gln19Glu) in aqueous‐organic media
Authors: Versari Andrea , Ménard Robert , Lortie Robert 
Published: August 2002

AbstractA mutant of the cysteine protease papain, displaying nitrile hydratase and amidase activities, was expressed in Pichia pastoris and used for the hydrolysis of peptide nitriles in aqueous‐organic media. The rate of hydrolysis of these nitriles is lowered by increasing acetone concentration. This is caused by an increase of the Michaelis constant, and a variation of Vmax proportional to the amount of water in the mixture. The hydrolysis of the amide is less affected by the increase in co‐solvent, which results in lower accumulation of this intermediate product. With the peptide nitrile tested, high nitrile concentrations could be used to promote the production of the amide and prevent its hydrolysis to the acid by diminishing the relative rate of amide hydrolysis. A number of non‐peptidyl nitriles were also tested as potential substrates but activity was detected for only one compound with structural resemblance to peptide nitriles. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 9–14, 2002.
The meaning of malingering data: further applications of Bayes' theorem
Authors: Mossman Douglas 
Published: August 2002

AbstractA previous Behavioral Sciences and the Law article (Mossman & Hart, 1996) asserted that information from malingering tests is best conceptualized using Bayes' theorem, and that courts therefore deserve Bayesian interpretations when mental health professionals present evidence about malingering. Mossman and Hart gave several examples of estimated Bayesian posterior probabilities, but they did not systematically address how one constructs confidence intervals for these estimates. This article explains how the usually imperfect nature of humanly created diagnostic tests mandates Bayesian interpretations of test results, and describes methods for generating confidence intervals for posterior probabilities. Sample calculations show that Bayesian reasoning is quite feasible and would not require investigators to expend unusual efforts when constructing and validating malingering instruments. Bayesian interpretations most accurately capture what malingering tests do: provide information that alters one's beliefs about the likelihood of malingering. Copyright © 2000 John Wiley & Sons, Ltd.
Transcatheter closure of a 16 mm hypertensive patent ductus arteriosus with the Amplatzer muscular VSD occluder
Authors: Demkow Marcin , Ruzyllo Witold , Siudalska Hanna , Kepka Cezary 
Published: August 2002

AbstractThere is little experience with transcatheter closure of very large, hypertensive patent ductus arteriosus. We present a case of successful closure of a 16 mm ductus with the Amplatzer VSD occluder, a device originally designed for transcatheter closure of congenital muscular ventricular septal defects. To our best knowledge this is the largest ductus ever closed by an interventional technique. Cathet Cardiovasc Intervent 2001;52:359–362. © 2001 Wiley‐Liss, Inc.
Chiral HPLC separation and CD spectra of the enantiomers of the alkaloid tacamonine and related compounds
Authors: Caccamese Salvatore , Principato Grazia , Jokela Reija , Tolvanen Arto , Din Belle David 
Published: August 2002

AbstractThe HPLC enantiomeric separation of racemic indole alkaloids tacamonine, 17α‐hydroxytacamonine, deethyleburnamonine, and vindeburnol was accomplished using Chiralpak AD and Chiralcel OD as chiral stationary phases. Small structural differences affect the enantioselectivity ability of these phases. Single enantiomers of tacamonine and vindeburnol were isolated by semipreparative HPLC and their CD spectra and optical rotations were measured. Chirality 13:691–693, 2001. © 2001 Wiley‐Liss, Inc.
Remodeling of the actin cytoskeleton of target hepatocytes and NK cells during induction of apoptosis
Authors: Blom W. Marty , de Bont Hans J.G.M. , Meijerman Irma , Kuppen Peter J.K. , van der Meulen Hans , Mulder Gerard J. , Nagelkerke J. Fred 
Published: August 2002

AbstractNatural Killer cells are immune cells that recognize and eliminate altered and non‐self cells from the circulation. To study the interaction between NK cells and target cells, we set up an experimental system consisting of rat Interleukin‐2 activated Natural Killer cells (A‐NK cells) and rat hepatocytes with a masked Major Histocompatibility Complex (MHC). The masking of the MHC induces recognition of the hepatocytes by the NK cells as non‐self. We showed that in vitro apoptosis is rapidly induced in the hepatocytes [Blom et al., 1999] after co‐incubation with A‐NK cells. Now we describe the morphological changes that occur during and after interaction of A‐NK cells with hepatocytes. Confocal laser scanning microscopy showed that the actin cytoskeleton of the NK cells was remodeled during attack of hepatocytes. Some NK cells were in close contact with the hepatocytes while others had formed actin‐containing dendrites of varying length that made contact with the hepatocytes. However, dendrite formation is not obligatory for induction of apoptosis because cells that were unable to form these did induce FAS‐dependent apoptosis in hepatocytes. Apparently both direct as well as distant contact resulted in apoptosis. Formation of the dendrites was calcium‐dependent as EGTA largely prevented it. Importantly, chelation of the calcium also suppressed killing of the hepatocytes. Within 1 h after addition of the A‐NK cells, morphological changes in hepatocytes that are characteristic of apoptosis, such as the formation of apoptotic bodies and fragmented nuclei, became apparent. Specifically, the actin cytoskeleton of the hepatocytes was remodeled resulting in the formation of the apoptotic bodies. Inhibition of caspase activity by z‐Val‐Ala‐DL‐Asp‐fluoromethylketone (100 μM) partly protected against the rearrangement of the actin filaments in the hepatocytes. Cell Motil. Cytoskeleton 49:78–92, 2001. © 2001 Wiley‐Liss, Inc.
CPT‐11 plus cisplatin in patients with advanced, untreated gastric or gastroesophageal junction carcinoma
Authors: Ajani Jaffer A. , Baker Jackie , Pisters Peter W. T. , Ho Linus , Mansfield Paul F. , Feig Barry W. , Charnsangavej Chusilp 
Published: August 2002

AbstractBACKGROUNDThis Phase II study assessed the response rate and toxicity profile of the combination CPT‐11 and cisplatin administered weekly to patients with untreated, advanced adenocarcinoma of the stomach or the gastroesophageal junction.METHODSPatients with histologic proof of adenocarcinoma of the stomach or the gastroesophageal junction with adequate liver, kidney, and bone marrow functions were treated with 65 mg/m2 CPT‐11 plus 30 mg/m2 cisplatin, both administered intravenously 1 day per week for 4 consecutive weeks, followed by a recovery period of 2 consecutive weeks. The response rate, time to disease progression, survival, and toxic effects were analyzed.RESULTSThirty‐six of 38 registered patients (95%) were assessable. The median number of 6‐week cycles per patient was 2.5 (range, 1–7 6‐week cycles). Four patients (11%) achieved a complete response, and 17 patients (47%) had a partial response for an overall response rate of 58%. The median time to progression of carcinoma was 24 weeks, and the median survival was 9 months (range, 1–23+ months). There was one treatment‐related death. Major toxic effects included diarrhea, neutropenia, and fatigue. Ninety percent of all planned doses were delivered on time; however, 53 of 79 canceled or delayed weekly doses (66%) occurred in the third or fourth week of the therapy cycle.CONCLUSIONSThe combination of CPT‐11 and cisplatin is active against gastric or gastroesophageal adenocarcinoma and needs to be studied further. A modification in doses and schedules may be warranted to make the regimen more tolerable to patients. The addition of other active drugs or radiation therapy to this regimen would be of interest. Cancer 2002;94:641–6. © 2002 American Cancer Society.DOI 10.1002/cncr.10279
Sexual dimorphisms in a copulatory neuromuscular system in the green anole lizard
Authors: Ruiz Claudia C. , Wade Juli 
Published: August 2002

AbstractSexual dimorphisms in neuromuscular systems have been investigated in several vertebrate groups, but data on reptiles are limited. The present studies were designed to establish the copulatory neuromuscular system of the green anole lizard (Anolis carolinensis) as an appropriate model. Like mammals, male reptiles have copulatory organs. However, each individual has two “hemipenes” that are controlled by bilateral sets of muscles. First, the anatomy of the hemipenes and associated muscles was described in males and the same anatomical region examined in females. Second, spinal motoneurons innervating one of these muscles, the transversus penis (TPN), were localized by using the retrograde tracer biocytin. They were detected in the last trunk and first sacral segments (T17–S1). Third, motoneuron number and soma size were assessed in Nissl‐stained sections of spinal cord segments T17–S1 of breeding males and females. Male‐biased sexual dimorphisms were detected in both measures, but the motoneurons innervating a tail muscle, the caudifemoralis (CF), are also located in the same region of cord. Therefore, in the last study, the CF was injected with biocytin in both sexes to eliminate its motoneurons from the analysis and gain a more accurate representation of the TPN motoneuron pool. An equivalent number of CF motoneurons were labeled in both sexes, and the results from the previous study were replicated. Thus, similar to other vertebrate models, parallels between morphology and function exist in the green anole copulatory system. Future investigations will broaden the comparative perspective on mechanisms regulating sexual dimorphisms relating to reproductive behaviors in vertebrates. J. Comp. Neurol. 443:289–297, 2002. © 2002 Wiley‐Liss, Inc.
Spatial arrangement of cerebro‐pontine terminals
Authors: Schwarz Cornelius , Möck Martin 
Published: August 2002

AbstractUnderstanding the interaction of the cerebral cortex and cerebellum requires knowledge of the highly complex spatial characteristics of cerebro‐cerebellar signal transfer. Cerebro‐pontine fibers from one neocortical site terminate in several sharply demarcated patches across large parts of the pontine nuclei (PN), and fibers from different neocortical areas terminate in the same pontine region. To determine whether projections from segregated neocortical sites overlap in the PN, we studied double anterograde tracing of cerebro‐pontine terminals from large parts of rat neocortex. In none of these experiments, including double injection into two functionally related areas, were we able to demonstrate overlapping patches, although close spatial relationships were always detected. This non‐overlapping distribution is consistent with a compartmentalized organization of the cerebro‐pontine projection and may be the basis of the fractured type of maps found in the cerebellar granular layer. The critical distance between two sites on the neocortical surface that project to non‐overlapping patches in the PN was found to be 600 μm, by using double injection within the whisker representation of the primary somatosensory area. This matches the diameter of dendritic trees of layer 5 projection neurons, indicating that non‐overlapping populations of neocortical projection neurons possess non‐overlapping patches of pontine terminals. Estimations based on this critical distance and the pontine volume anterogradely labeled by one injection site indicate that the size of the PN may be well suited to accommodate a complete set of non‐overlapping pontine patches from all possible neocortical sites. J. Comp. Neurol. 435:418–432, 2001. © 2001 Wiley‐Liss, Inc.
Expression of SCG10 and stathmin proteins in the rat olfactory system during development and axonal regeneration
Authors: Pellier‐Monnin Véronique , Astic Liliane , Bichet Sandrine , Riederer Beat M. , Grenningloh Gabriele 
Published: August 2002

AbstractThe membrane‐associated protein SCG10 is expressed specifically by neuronal cells. Recent experiments have suggested that it promotes neurite outgrowth by increasing microtubule dynamics in growth cones. SCG10 is related to the ubiquitous but neuron‐enriched cytosolic protein stathmin. To better understand the role played by SCG10 and stathmin in vivo, we have analyzed the expression and localization of these proteins in both the olfactory epithelium and the olfactory bulb in developing and adult rats, as well as in adult bulbectomized rats. The olfactory epithelium is exceptional in that olfactory receptor neurons constantly regenerate and reinnervate the olfactory bulb throughout animal life‐span. SCG10 and stathmin expression in the olfactory receptor neurons was found to be regulated during embryonic and postnatal development and to correlate with neuronal maturation. Whereas SCG10 expression was restricted to immature olfactory receptor neurons (GAP‐43–positive, olfactory marker protein–negative), stathmin was also expressed by the basal cells. In the olfactory bulb of postnatal and adult rats, a moderate to strong SCG10 immunoreactivity was present in the olfactory nerve layer, whereas no labeling was detected in the glomerular layer. Olfactory glomeruli also showed no apparent immunoreactivity for several cytoskeletal proteins such as tubulin and microtubule‐associated proteins. In unilaterally bulbectomized rats, SCG10 and stathmin were seen to be up‐regulated in the regenerating olfactory epithelium at postsurgery stages corresponding to olfactory axon regeneration. Our data strongly suggest that, in vivo, both SCG10 and stathmin may play a role in axonal outgrowth during ontogenesis as well as during axonal regeneration. J. Comp. Neurol. 433:239–254, 2001. © 2001 Wiley‐Liss, Inc.