bluuebunny/crossref_metadata_2025_split huggingface dataset:
Infrared and thermal analyses of polybenzoxazine and polycarbonate blends
Authors: Ishida Hatsuo , Lee Yu‐Hsin 
Published: August 2002

AbstractThe thermal properties of physical blends containing benzoxazine monomer and polycarbonate (PC) were studied by nonisothermal differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The ring‐opening reaction and subsequent polymerization reaction of the benzoxazine were inhibited significantly by the presence of polycarbonate. The glass‐transition temperature of the resulting blends decreased as the concentration of polycarbonate increased and deviated markedly from the Fox equation. An earlier degradation event appeared in the blend with 11 and 33 wt % of PC. In addition, FTIR was used to study the extent of the polymerization reaction as well as the hydrogen‐bonding behavior. Intermolecular hydrogen bonding between PC and cured polybenzoxazine appeared after 1 h of isothermal curing at 180°C and continued throughout the entire curing process. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1021–1034, 2001
Permeation of oxygen and water vapor through EVOH films as influenced by relative humidity
Authors: Zhang Zhongbin , Britt Ian J. , Tung Marvin A. 
Published: August 2002

AbstractThe transport properties of oxygen and water vapor through EVOH films as functions of relative humidity (RH) and temperature were studied. The results of oxygen and water vapor permeation demonstrated that temperature and RH markedly affected barrier properties of these films. In general, the EVOH films had minimal oxygen and water vapor permeabilities at a low RH, attributed to the reduced mobility of the polymer resulting from strong interactions between small water molecules and the polymeric matrix at low RH. Beyond 75% RH, the permeabilities increased considerably. In addition, the barrier performance of the EVOH films was found to be dependent on their ethylene content and orientation. From the experimental data, semiempirical equations describing oxygen transmission rates (O2TR) as functions of RH and temperature were developed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1866–1872, 2001
Toughening of polypropylene with styrene/ethylene‐butylene/styrene tri‐block copolymer: Effects of mixing condition and elastomer content
Authors: Bassani A. , Pessan L. A. , Hage E. 
Published: August 2002

AbstractThe effect of processing conditions and elastomer content on the toughening of Polypropylene (PP) by melt blending with styrene/ethylene‐butylene/styrene tri‐block copolymer (SEBS) in a twin‐screw extruder has been investigated. The parameters analyzed were: temperature profile, screw speed, and feed rate of the blend components. Their effect was evaluated through the mechanical properties (tensile strength and Izod impact resistance at room temperature) as well as the morphology of the dispersed phase by means of scanning electron microscopy (SEM). The results showed that the impact resistance increases with increasing rotor speed and feed rate and decreases when the temperature profile is increased. The parameter with the greatest effect on the mechanical properties was the variation in rotor speed. Despite the fact that impact resistance as high as 25 times that of neat PP has been achieved with blends containing 20 wt % SEBS, no significant modification in phase morphology has been observed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2185–2193, 2001
A metal binding in the polypeptide chain improves the folding efficiency of a denatured and reduced protein
Authors: Ohkuri Takatoshi , Ueda Tadashi , Yoshida Yuichiro , Abe Yoshito , Hamasaki Naotaka , Imoto Taiji 
Published: August 2002

AbstractIn order to examine the effect of a metal binding to the polypeptide chain on the aggregation of a protein in the refolding process, we prepared a mutant hen lysozyme possessing the same Ca2+ binding site as in human α‐lactalbumin by Escherichia coli expression system (Ser−1 CaB lysozyme). In the presence of 2 mM CaCl2, the refolding yield of Ser−1 CaB lysozyme at a low protein concentration (25 μg/mL) was similar to that of the wild‐type lysozyme (80%), but that at high protein concentration (200 μg/mL) decreased (15%) due to aggregation comparing to that of the wild‐type lysozyme (45%). However, the refolding yield of Ser−1 CaB lysozyme in the presence of 100 mM CaCl2 even at a protein concentration of 200 μg/mL was 80% and was higher than that of the wild‐type lysozyme. From analysis of chemical shift changes of the cross peaks in the backbone region of total correlated spectroscopy (TOCSY) spectra of a decapeptide possessing the same calcium binding site as in Ser−1 CaB lysozyme in the presence of various concentrations of Ca2+, it was suggested that the dissociation constant of Ca2+‐peptide complex was estimated to be 20–36 mM. Moreover, the solubility of the denatured Ser−1 CaB lysozyme in the presence of 100 mM CaCl2 was higher than that in the presence of 2 mM CaCl2 whereas the solubility of the denatured Ser−1 lysozyme in the presence of 100 mM CaCl2 was not higher than that in the presence of 2 mM CaCl2. Therefore, it was concluded that the reduced lysozyme possessing the Ca2+ binding site was efficiently folded in the presence of high concentration of Ca2+ (100 mM) even at high protein concentration due to depression of aggregation by the binding of Ca2+ to the polypeptide chain in Ser−1 CaB lysozyme. © 2002 Wiley Periodicals, Inc. Biopolymers 64: 106–114, 2002
One‐step acclimatization of plantlets using a mist reactor
Authors: Correll M. J. , Weathers P. J. 
Published: August 2002

AbstractA mist reactor was used to grow and acclimatize carnation plants in vitro without using ex vitro acclimatization techniques. The acclimatization protocol in the reactor consisted of altering the mist‐on period during the course of the culture period and a stepwise reduction in the relative humidity surrounding the plants from 98% to 70% relative humidity (RH) during the final week of in vitro growth. After transfer and further growth in a greenhouse for 5 weeks, survival was 91% for plants grown in reactors, 81% from vented boxes, and 50% from unvented boxes. Ex vitro survival directly correlated with increased in vitro rooting and decreased hyperhydration. In vitro rooting also correlated with high‐quality plants, but did not significantly correlate with low hyperhydration, as normal plants often lacked roots. After 5 weeks in the greenhouse, the quantity of mid‐ and high‐quality plants obtained from reactors and ventilated boxes was similar. Conditions in the mist reactor can be manipulated to produce plants that are readily acclimatized and are equal or better in quality and yield than plants produced using conventional methods. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 253–258, 2001.
Characterization of the stability of recombinant protein production in the GS‐NS0 expression system
Authors: Barnes Louise M. , Bentley Catherine M. , Dickson Alan J. 
Published: August 2002

AbstractThe GS‐NS0 system is an important mammalian expression system used largely within industry for the high‐level expression of recombinant proteins for therapeutic use. It is essential that the productivity of this system remains stable throughout culture expansion for the successful long‐term production of recombinant proteins. Here we present a study of the stability of recombinant protein production from unamplified GS‐NS0 cell lines over extended period of continuous culture. The cell lines used in this study were generated by the transfection of NS0 cells with DNA encoding for a secreted recombinant protein and by two subsequent rounds of limiting dilution cloning prior to analysis of stability. The stability of recombinant protein production was assessed at intervals over a period of 134 days using repeated batch culture in shake flasks. Heterogeneous stability was identified. The productivity of some clones remained consistent throughout 134 days of continuous culture. Others exhibit rapid and progressive loss of productivity. Analysis of the causal relationships underlying stability indicates that the initial transfectant determines the susceptibility to loss or retention of productivity. Selection of production clones on the basis of growth and productivity alone will not predict stability during long‐term culture. Our research indicates that stable high‐producing clones can readily be obtained from use of the GS‐NS0 system in the absence of amplification but there may be molecular features of the original transfectants that could serve as very important predictive indicators of the stability of recombinant protein production. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 261–270, 2001.
dELL, a drosophila homologue of transcription elongation factor ELL (eleven‐nineteen lysine rich leukemia), is required for early development
Authors: Khattak Shahryar , Im Hogune , Park Taeju , Ahnn Joohong , Spoerel Nikolaus A. 
Published: August 2002

AbstractELL (Eleven‐nineteen Lysine rich Leukemia) is known to be an elongation factor resembling elongin for RNA polymerase II transcription. A homologue of human ELL (hELL) was identified in Drosophila melanogaster (dELL) and several cDNA clones were isolated from the embryonic cDNA library. We showed that dELL is expressed mainly in the ovaries and early embryonic stages by developmental Northern blot. dELL encodes a protein of 912 amino acids which is substantially longer than the hELL (612 aa). Immunostaining revealed that dELL was localized to nuclei in early embryos and to nuclei of nurse cells and follicle cells in the ovary suggesting its important role in early development of drosophila. To elucidate the function of this gene in drosophila, P‐element mobilization was performed by utilizing a P‐element inserted upstream of dELL. Southern analysis showed that isolated mutants are internal P‐element deletions. These P‐element deletions can now be used to isolate dELL mutations by EMS mutagenesis. Copyright © 2001 John Wiley & Sons, Ltd.
Gamma synuclein: Subcellular localization in neuronal and non‐neuronal cells and effect on signal transduction
Authors: Surguchov Andrei , Palazzo Robert E. , Surgucheva Irina 
Published: August 2002

AbstractSynucleins are small, highly conserved proteins in vertebrates, especially abundant in neurons and typically enriched in presynaptic terminals. α‐Synuclein protein and a fragment of it, called NAC, have been found in association with pathological lesions of neurodegenerative diseases. Recently, mutations in a α‐synuclein gene have been reported in families susceptible to an inherited form of Parkinson's diseases. In addition, α‐synuclein has been implicated in the pathophysiology of other neurodegenerative diseases, including Alzheimer's disease and multiple system atrophy. Far less is known about other members of the synuclein family, β‐ and γ‐synucleins. γ‐synuclein is up‐regulated in several types of cancer and may affect the integrity of the neurofilament network, while its bovine ortholog, synoretin, activates the Elk‐1 signal transduction pathway. In this paper, we present data about the localization and properties of human and bovine γ‐synuclein in several neuronal and non‐neuronal cell cultures derived from ocular tissues. We show that γ‐synuclein is present in the perinuclear area and is localized to centrosomes in several types of human interphase cells and in bovine retinal pigment epithelium. In mitotic cells, γ‐synuclein staining is localized to the poles of the spindle. Further, overexpression of synoretin in retinoblastoma cells up‐regulates MAPK and Elk‐1. These results support the view that γ‐synuclein is a centrosome protein that may be involved in signal transduction pathways. Cell Motil. Cytoskeleton 49:218–228, 2001. © 2001 Wiley‐Liss, Inc.
Axonal projections of pulmonary slowly adapting receptor relay neurons in the rat
Authors: Ezure Kazuhisa , Tanaka Ikuko , Saito Yoshiaki , Otake Kazuyoshi 
Published: August 2002

AbstractWe elucidated efferent projections of second‐order relay neurons (P‐cells) activated by afferents originating from slowly adapting pulmonary receptors (SARs) to determine the central pathway of the SAR‐evoked reflexes. Special attention was paid to visualizing the P‐cell projections within the nucleus tractus solitarii (NTS), which may correspond to the inhibitory pathway from P‐cells to second‐order relay neurons (RAR‐cells) of rapidly adapting pulmonary receptors. P‐cells were recorded from the NTS in Nembutal‐anesthetized, paralyzed, and artificially ventilated rats. First, we used electrophysiological methods of antidromic mapping and showed that the majority of the P‐cells examined projected their axons to the caudal NTS and to the dorsolateral pons corresponding to the parabrachial complex. Second, a mixture of HRP and Neurobiotin was injected intracellularly or juxtramembranously into P‐cells. (1) Stained P‐cells (n = 7) were located laterally to the solitary tract and had dendrites extending characteristically along the lateral border of the solitary tract. (2) All P‐cells had stem axons projecting to the ipsilateral medulla. Of these, the axons from five P‐cells projected to the nucleus ambiguus and its vicinity with distributing boutons. Some of these axons further ascended in the ventrolateral medulla, and distributed boutons in the areas ventral or ventrolateral to the nucleus ambiguus. (3) All the P‐cells had axonal branches with boutons in the NTS area. In particular, axons from three P‐cells projected bilaterally to the medial NTS caudal to the obex, i.e., to the area of RAR‐cells. These results show anatomic substrates for the connections implicated in the P‐cell inhibition of RAR‐cells as well as the SAR‐induced respiratory reflexes. J. Comp. Neurol. 446:81–94, 2002. © 2002 Wiley‐Liss, Inc.
TrkB‐like immunoreactivity is present on geniculocortical afferents in layer IV of kitten primary visual cortex
Authors: Silver Michael A. , Stryker Michael P. 
Published: August 2002

AbstractExogenous administration of the neurotrophins brain‐derived neurotrophic factor (BDNF) or neurotrophin‐4/5 (NT‐4/5), or blockade of their endogenous actions, have been reported to affect the anatomic organization and physiological responses of neurons in developing mammalian primary visual cortex. Experimental alteration of levels of these neurotrophic factors can also influence the morphology of the geniculocortical afferents that project from the lateral geniculate nucleus (LGN) to primary visual cortex. BDNF and NT‐4/5 are ligands of the TrkB tyrosine kinase receptor. Although multiple populations of cortical neurons express TrkB, it is not known whether geniculocortical afferents express this receptor on their axon branches in visual cortex. We have anatomically labeled geniculocortical afferents of postnatal day 40 kittens with the anterograde neuronal tracer Phaseolus vulgaris leucoagglutinin (PHA‐L) and performed double‐label immunofluorescence with a panel of anti‐TrkB antibodies. Confocal microscopy and object‐based colocalization analysis were used to measure levels of TrkB‐like immunoreactivity (IR) on geniculocortical afferents in layer IV of primary visual cortex. By using a conservative analysis involving a comparison of measured colocalization with the amount of colocalization expected based on random overlap of TrkB puncta and PHA‐L–labeled afferents, 3 of 5 anti‐TrkB antibodies tested showed significant colocalization with the geniculocortical axons. Results for the other two antibodies were indeterminate. The indices obtained for colocalization of TrkB and geniculocortical afferents were also compared with the equivalent index obtained for GAD65, a protein that has a similar overall expression pattern to that of TrkB but is not expressed on geniculocortical axons. This analysis indicated that TrkB was present on geniculocortical axons for all five TrkB antibodies tested. TrkB‐like IR was also observed on neuronal somata in the LGN. These results indicate that TrkB receptors on geniculocortical afferents are potential mediators of the actions of BDNF and NT‐4/5 in developing visual cortex. J. Comp. Neurol. 436:391–398, 2001. © 2001 Wiley‐Liss, Inc.
Flow cytometric discrimination of various phycobilin‐containing phytoplankton groups in a hypertrophic reservoir
Authors: Becker Annette , Meister Armin , Wilhelm Christian 
Published: August 2002

AbstractBackgroundKnowledge of phytoplankton structure is important information in water quality control. Lake restoration and sanitation measures in particular must be evaluated on the organismic level to valuate biological effects and assess the risk of potentially toxic Cyanobacteria blooms. We used and comparatively tested three independent methods for phytoplankton analysis in a hypertrophic reservoir under restoration.MethodsNine unialgal cultures and outdoor samples were examined by high‐performance liquid chromatography pigment analysis, microscopical cell counting, and flow cytometric (FCM) light scatter and fluorescence analysis to measure the percentage contribution of the major algal groups to chlorophyll a and biovolume. The FCM instrument settings and identification criteria were developed using a single excitation wavelength at 514 nm to differentiate nine algal species representing the major groups of algae. Fluorescence was detected at 585, 620, 650, and 680 nm.ResultsThe results show that FCM is the only method for determining changes in the phytoplankton composition on both a chlorophyll a and biovolume basis.ConclusionsEach of the three methods has specific advantages and disadvantages, and should be chosen depending on the experimental problem. FCM sorting allows the combination of all three and offers further new perspectives. Cytometry 48:45–57, 2002. © 2002 Wiley‐Liss, Inc.
Fine‐needle aspiration cytology of phyllodes tumors
Authors: Jayaram Gita , Sthaneshwar Pavai 
Published: August 2002

AbstractBreast lesions with a significant spindle cell or mesenchymal component are not commonly encountered in fine‐needle aspiration (FNA) cytologic material and include a heterologous variety of benign and malignant conditions, with phyllodes tumors (PTs) being the foremost differential diagnostic consideration. This study comprises 28 tumors diagnosed histologically as PT in which FNAC material was available for review. Histological sections and cytological smears from these cases were retrieved and subjected to detailed morphological review. Cytological parameters assessed included ratio of stroma to epithelium, pattern characteristics and cytological characteristics of the stromal, and epithelial components and the background cells. Large and hypercellular stroma fragments, dissociated spindle and plump stromal cells, often accompanied by large, folded sheets of epithelium were cytological features that characterized PT. Smears from malignant PT showed predominantly or solely mesenchymal components. FNAC was a highly reliable procedure for the diagnosis of PT, giving an accuracy rate of 92.8%. Diagn. Cytopathol. 2002;26:222–227. © 2002 Wiley‐Liss, Inc.
Calcifying aponeurotic fibroma features seen on fine‐needle aspiration biopsy: Case report and brief review of the literature
Authors: Tai Lisa H. , Johnston James O. , Klein Harvey Z. , Rowland John , Sudilovsky Daniel 
Published: August 2002

AbstractCalcifying aponeurotic fibroma is a rare benign soft tissue proliferation, which occurs in the distal extremities in children. We describe a case of calcifying aponeurotic fibroma of the hand in a 9 year‐old male diagnosed by FNA. Clinically and radiographically this mass was felt to be suspicious for sarcoma, likely alveolar rhabdomyosarcoma. Cytologic examination revealed benign appearing spindled cells, chondroid cells, multinucleated giant cells and calcific debris. These features recapitulate the classic histologic features of calcifying aponeurotic fibroma. Conservative excision was performed and histologic exam confirmed the diagnosis. To the authors' knowledge, this is the first description of the cytologic features of this entity. Diagn. Cytopathol. 24:336–339, 2001. © 2001 Wiley‐Liss, Inc.
Pyrazolo[4,3‐e]1,2,4‐triazolo[1,5‐c]pyrimidine derivatives: A new pharmacological tool for the characterization of the human A3 adenosine receptor
Authors: Baraldi Pier Giovanni , Cacciari Barbara , Romagnoli Romeo , Spalluto Giampiero , Varani Katia , Gessi Stefania , Merighi Stefania , Borea Pier Andrea 
Published: August 2002

AbstractAdenosine regulates many physiological functions by interaction with four different G‐protein‐coupled receptors classified as A1, A2A, A2B, and A3. While adenosine A1 and A2A receptor subtypes have been pharmacologically characterized through the use of selective ligands, the A2B and A3 adenosine receptor subtypes are presently under study in order to better understand their physio‐pathological functions. In particular, activation of adenosine A3 receptors has been shown to stimulate phospholipase C and D and to inhibit adenylate cyclase. Activation of A3 adenosine receptors also causes the release of inflammatory mediators such as histamine from mast cells, which are responsible for processes such as inflammation and hypotension. For these reasons, it has been suggested that A3 adenosine receptor antagonists can be considered potential drugs for the treatment of asthma and inflammation. In the last few years different classes of heterocyclic compounds have been identified as A3 adenosine antagonists, but none of the tested compounds showed significant selectivity for A3 adenosine receptor subtype. Herein, we report our recent results on a class of pyrazolo[4,3‐e]1,2,4‐triazolo[1,5‐c]pyrimidine derivatives as a new class of potent and selective human A3 adenosine receptor antagonists. The full characterization of the first high‐affinity radioligand antagonist for this receptor subtype, designated [3H] MRE3008F20, is briefly summarized. Drug Dev. Res. 52:406–415, 2001. © 2001 Wiley‐Liss, Inc.
Cross‐species investigations of prenatal experience, hatching behavior, and postnatal behavioral laterality
Authors: Casey Michael Bernard , Sleigh Merry J. 
Published: August 2002

AbstractTurning biases have been reported in some mammalian species, but less is known about such biases in nonmammalians. This study investigated turning biases in domestic chicks, bobwhite and Japanese quail, leopard geckos, and snapping turtles. Domestic chicks (white leghorn and bantam) and bobwhite quail demonstrate strong group laterality. Japanese quail chicks, snapping turtles, and leopard geckos demonstrate no significant group bias. Results are discussed with regard to differences in embryonic experience, hatching behavior, and postnatal environment. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 39: 84–91, 2001
Evidence for a glycosaminoglycan on the nudel protein important for dorsoventral patterning of the drosophila embryo
Authors: Turcotte Cynthia L. , Hashimoto Carl 
Published: August 2002

AbstractDorsoventral patterning of the Drosophila embryo requires Nudel, a large mosaic protein with a protease domain. Previous studies have implicated Nudel's protease domain as the trigger of a proteolytic cascade that activates the Toll signaling pathway to establish dorsoventral polarity in the embryo. However, the function of other regions of Nudel has been unclear. By using two‐dimensional gel electrophoresis and site‐directed mutagenesis, we have obtained evidence that the N‐terminal region of Nudel contains a site for glycosaminoglycan (GAG) attachment that is required for dorsoventral patterning. Disruption of this site blocks a disulfide‐based association between N‐ and C‐terminal Nudel polypeptides and proteolytic activation of Nudel's protease domain. We discuss how a GAG chain on Nudel might be required for Nudel protease activation. © 2002 Wiley‐Liss, Inc.