bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and physical properties of N‐defunctionalized derivatives of poly(aspartic acid)
Authors: Katritzky Alan R. , Yao Jiangchao , Qi Ming , Qiu Guofang , Bao Weilang , Yang Baozhen , Denisko Olga , Davis Shannon , Zhang Jingen 
Published: August 2002

AbstractA number of N‐substituted poly(aspartic acid)s was prepared under mild conditions using the silylation–alkylation technique. Their physical properties were studied. Free swelling capacity (FSC) tests were performed for polymers obtained by crosslinking the parent poly(aspartic acid) as well as its defunctionalized derivatives. The hypothesis that H‐bonding is critical in superabsorbency was demonstrated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 85–90, 2001
Preparation and phenol captivating properties of polyvinylpyrrolidone‐montmorillonite hybrid materials
Authors: Gultek Ahmet , Seckin Turgay , Onal Yunus , Icduygu M. Galip 
Published: August 2002

AbstractMontmorillonite minerals were modified in two distinct steps in order to remove hydroxlated toxicants from the aqueous environment. At first, the montmorillonite minerals were acrylated with the silylating agent γ‐methcaryloxypropyl trimethoxysilane to give a product denoted as TAY‐10. In the second step these materials readily reacted with vinylpyrrolidone to form copolymers covalently bonded to the clay. All hybrid materials were characterized by FTIR spectroscopy, thermogravimetry, X‐ray diffractometry, SEM, and differential thermal analysis. The original montmorillonite structure was maintained for the copolymer modified surfaces. Different loadings of polyvinylpyrrolidone (PVP) were examined to arrive at the optimal conditions for the removal of toxicants from the aqueous environment. The presence of the PVP enhanced the adsorption capacity of the clay toward phenolic compounds from solution as evidenced by the retention percent that was as high as 98.9%. These results demonstrated the feasibility of utilizing a PVP modified clay as a thermally recyclable adsorbent for environmental pollutants. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 512–519, 2001
Crosslinkable positive‐tone photoresist comprising polymers with pendant carboxyl groups
Authors: Liu Jui‐Hsiang , Shi Chih‐Hung , Chen We‐Tin 
Published: August 2002

AbstractPoly(methacrylic acid‐co‐t‐butylmethacrylate‐co‐bornylmethacrylate) was synthesized and its application to a crosslinkable positive photoresist was investigated. The existence of pendant alicyclic bornyl groups increased the thermostability of copolymers; however, a decrease in the acid‐catalyzed deprotection of pendant t‐butyl groups led to a decrease in the sensitivity of the positive‐tone photoresist. The thermostability of the relief polymeric patterns of the positive‐tone photoresist was appreciably improved effectively because of the acid‐catalyzed dehydration crosslinking of pendant carboxyl groups. Thermogravimetric properties of binder resins, exposure characteristics, and sensitivity and resolution of the photoresist were all investigated. Lithographic evaluation of the curable positive‐tone photoresists was also estimated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1014–1020, 2001
Hydrogel of biodegradable cellulose derivatives. II. Effect of some factors on radiation‐induced crosslinking of CMC
Authors: Wach Radoslaw A. , Mitomo Hiroshi , Yoshii Fumio , Kume Tamikazu 
Published: August 2002

AbstractThe effects of high‐energy radiation on sodium carboxymethylcellulose (CMC) with a degree of substitution of 2.2 were investigated. Moderate CMC concentrations formed hydrogels by intermolecular crosslinking. Significant influences on the results of irradiation, in addition to the concentration, were the dose and dose rate and the presence of oxygen in the surrounding atmosphere. Up to a 95% gel fraction was obtained from 50 and 60% CMC solutions irradiated by an electron beam. CMC hydrogels swelled by absorbing more than 800 g of water per gram of dry gel at a low applied dose. Swelling tests of CMC hydrogels in salt solutions and in media of various pHs showed that the swelling decreased with the salt concentration and was lower at acidic pH values. Radiation yields of crosslinking and scission were calculated on the basis of gel–sol analysis. Crosslinked CMC, in the form of the hydrogel, was degraded by the action of cellulase enzyme, thereby entering the class of environmentally friendly polymers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3030–3037, 2001
Postpolymerization of quaternary ammonium acrylate polymer produced by electropolymerization
Authors: Lin Thong‐Yueh , Chen Min‐Hua , Chou Tse‐Chuan 
Published: August 2002

AbstractPostpolymerization of dimethylaminoethylmethacrylate‐methyl chloride (DMAEM‐MC) electropolymerization, with Sn+2/EDTA as initiator, was studied. The factors that affect the stable average molecular weight of the polymer (MW∞) created by postpolymerization were investigated. The results indicate that the major factors affecting the MW∞ are the current density, pHi value, and the [Sn+2]i/[EDTA]i ratio. On the other hand, original reaction temperature, initial initiator concentration, and initial monomer concentration are minor factors affecting the postpolymerization polymer. Increasing the current density decreases the MW∞ at fixed operating conditions. The optimum [Sn+2]i /[EDTA]i ratio to obtain the highest MW∞ mainly depends on the pHi value. At 3.25 and 4.00 pHi values, the optimum [Sn+2]I/[EDTA]i ratio is 5.00. However, at 1.75 and 2.50 pHi values, the optimum ratios are 1.00 and 2.00, respectively. The results also reveal that increasing the original reaction temperature, initial initiator concentration, and initial monomer concentration increases the molecular weight. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1071–1076, 2001
Influence of degree of deacetylation on critical concentration of chitosan/dichloroacetic acid liquid‐crystalline solution
Authors: Dong Yanming , Xu Congyi , Wang Jianwei , Wu Yusong , Wang Mian , Ruan Yonghong 
Published: August 2002

AbstractWe prepared chitosans with various degrees of deacetylation (DDAs) by mixing completely deacetylated chitosan and acetic anhydride at room temperature without serious degradation and O‐substitution. We obtained a standard curve to measure DDA by plotting the IR absorbance ratio of A1560/A2880 against the known DDAs (from 1–100%) of 10 specimens. The effect of DDA on the critical concentration (C*) of chitosan/dichloroacetic acid solutions required to form mesophase was investigated by optical methods. A maximum C* value of 23 wt % appeared at a relative medium DDA (∼20%). The effect was explained by the disordering of chains with medium composition ratios of the copolymer of glucosamine and N‐acetyl glucosamine. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1204–1208, 2002
Use of focal species in marine conservation and management: a review and critique
Authors: Zacharias Mark A. , Roff John C. 
Published: August 2002

Abstract1. Focal species (i.e. indicators, keystones, umbrellas, and flagships) have been advocated for the management and conservation of natural environments. 2. The assumption has been that the presence or abundance of a focal species is a means to understanding the composition and/or state of the more complex community.3. We review the characteristics of focal species, and evaluate their appropriateness and utility judged against conservation objectives.4. It appears that indicator species (of both composition and condition) may be of greatest general utility, and that several types of focal species may exhibit useful indicator properties.Copyright © 2001 John Wiley & Sons, Ltd.
Conservation of otter (Lutra lutra) in a Mediterranean area: the importance of habitat quality and temporal variation in water availability
Authors: Prenda José , López‐Nieves Pedro , Bravo Rafael 
Published: August 2002

Abstract1. This study analyses quantitatively the association between habitat characteristics and annual variation in water availability on otter (Lutra lutra L.) distribution in a large Mediterranean area (13 717 km2) in southern Spain.2. There was a strong positive correlation between habitat quality, estimated after the two first components of a principal component analysis of a matrix of habitat variables×sites, and an index of otter presence/absence, otter presence being most commonly associated with unpolluted and undisturbed sites surrounded by woodland.3. After univariate analysis, the main freshwater habitat features were statistically different between sites with otters and sites lacking them. In general, otters occurred in medium‐sized fluvial habitats, with high bankside vegetation cover, unpolluted, with low or very low human disturbance and surrounded by forests or dehesas (Mediterranean‐like savannah).4. Water availability, inferred from the water balance, strongly influenced otter distribution and the type of water body used the most. As water availability increased so did the otter distribution range and during these periods they tended to colonize low‐order streams. During periods of water shortage, otters were usually found in high‐order streams and reservoirs, the only sites that kept water.5. This work shows that otter distribution in Mediterranean areas is strongly influenced by two factors — man‐induced habitat degradation and natural variability in water availability. The addition of the second factor to the first one introduces additional risks to the survival of otter populations in Mediterranean areas compared with more northerly and humid areas. Copyright © 2001 John Wiley & Sons, Ltd.
Anatomy and three‐dimensional reconstructions of the brain of the white whale (Delphinapterus leucas) from magnetic resonance images
Authors: Marino Lori , Murphy Timothy L. , Deweerd Amy L. , Morris John A. , Fobbs Archibald J. , Humblot Nathalie , Ridgway Sam H. , Johnson John I. 
Published: August 2002

AbstractMagnetic resonance imaging offers a means of observing the internal structure of the brain where traditional procedures of embedding, sectioning, staining, mounting, and microscopic examination of thousands of sections are not practical. Furthermore, internal structures can be analyzed in their precise quantitative spatial interrelationships, which is difficult to accomplish after the spatial distortions often accompanying histological processing. For these reasons, magnetic resonance imaging makes specimens that were traditionally difficult to analyze, more accessible. In the present study, images of the brain of a white whale (Beluga) Delphinapterus leucas were scanned in the coronal plane at 119 antero‐posterior levels. From these scans, a computer‐generated three‐dimensional model was constructed using the programs VoxelView and VoxelMath (Vital Images, Inc.). This model, wherein details of internal and external morphology are represented in three‐dimensional space, was then resectioned in orthogonal planes to produce corresponding series of “virtual” sections in the horizontal and sagittal planes. Sections in all three planes display the sizes and positions of such structures as the corpus callosum, internal capsule, cerebral peduncles, cerebral ventricles, certain thalamic nuclear groups, caudate nucleus, ventral striatum, pontine nuclei, cerebellar cortex and white matter, and all cerebral cortical sulci and gyri. Anat Rec 262:429–439, 2001. © 2001 Wiley‐Liss, Inc.
Spatial distribution of cell adhesion molecules on the peritoneal surface in the cecal perforation‐induced peritonitis
Authors: Johkura Kohei , Liang Yan , Cui Li , Ogiwara Naoko , Sasaki Katsunori 
Published: August 2002

AbstractFor understanding the immunological functions of the peritoneum, spatial localization of integrins and their ligands was studied by immuno‐SEM on the peritoneal surface of mice with cecal perforation‐induced peritonitis. The cecal peritoneum 24 hr after perforation was stained with specific antibodies against LFA‐1, Mac‐1, VLA‐4, ICAM‐1, VCAM‐1, and fibronectin diluted with cold University of Wisconsin (UW) solution in conjunction with immuno‐gold labeling. The spatial localization of those cell adhesion molecules was detected by backscatter electron (BSE) imaging with field emission scanning electron microscope (FESEM). Numerous leukocytes with diverse surface ultrastructure were observed on the peritoneal surface by FESEM. Some leukocytes were in contact with mesothelial cells, and others adhered to the exposed underlying connective tissue. The BSE imaging showed the ubiquitous distribution of Mac‐1 on all membrane domains of leukocytes, i.e., cell body, ruffles, and microvilli. In contrast, predominant expressions of LFA‐1 and VLA‐4 were discernible on ruffles/microvilli of some leukocytes. The mesothelial cells remaining in the inflamed area expressed both ICAM‐1 and VCAM‐1 on their microvilli. The fibronectin was detected on presumable collagen fibers and/or fibrin over the exposed smooth muscle layer as well as on fibrin extending between leukocyte aggregation. The spatial microlocalization of integrins was clarified on the leukocytes emigrated in peritonitis, and their ligands were detected on the inflamed peritoneum. Anat Rec 264:219–227, 2001. © 2001 Wiley‐Liss, Inc.
Combining and selecting characteristics of information use
Authors: Ruthven Ian , Lalmas Mounia , van Rijsbergen Keith 
Published: August 2002

AbstractIn this article we report on a series of experiments designed to investigate the combination of term and document weighting functions in information retrieval. We describe a series of weighting functions, each of which is based on how information is used within documents and collections, and use these weighting functions in two types of experiments: one based on combination of evidence for ad hoc retrieval, the other based on selective combination of evidence within a relevance feedback situation. We discuss the difficulties involved in predicting good combinations of evidence for ad hoc retrieval, and suggest the factors that may lead to the success or failure of combination. We also demonstrate how, in a relevance feedback situation, the relevance assessments can provide a good indication of how evidence should be selected for query term weighting. The use of relevance information to guide the combination process is shown to reduce the variability inherent in combination of evidence.
An expressive and efficient language for XML information retrieval
Authors: Chinenyanga Taurai Tapiwa , Kushmerick Nicholas 
Published: August 2002

AbstractSeveral languages for querying and transforming XML, including XML‐QL, Quilt, and XQL, have been proposed. However, these languages do not support ranked queries based on textual similarity, in the spirit of traditional IR. Several extensions to these XML query languages to support keyword search have been made, but the resulting languages cannot express IR‐style queries such as “find books and CDs with similar titles.” In some of these languages keywords are used merely as boolean filters without support for true ranked retrieval; others permit similarity calculations only between a data value and a constant, and thus cannot express the above query. WHIRL avoids both problems, but assumes relational data. We propose ELIXIR, an expressive and efficient language for XML information retrieval that extends XML‐QL with a textual similarity operator that can be used for similarity joins, so ELIXIR is sufficiently expressive to handle the sample query above. ELIXIR thus qualifies as a general‐purpose XML IR query language. Our central contribution is an efficient algorithm for answering ELIXIR queries that rewrites the original ELIXIR query into a series of XML‐QL queries to generate intermediate relational data, and uses WHIRL to efficiently evaluate the similarity operators on this intermediate data, yielding an XML document with nodes ranked by similarity. Our experiments demonstrate that our prototype scales well with the size of the query and the XML data.
Effect of 0.25 T static magnetic field on microcirculation in rabbits
Authors: Gmitrov Juraj , Ohkubo Chiyoji , Okano Hideyuki 
Published: August 2002

AbstractWe showed previously in rabbits that 0.2 and 0.35 T static magnetic field (SMF) modulated systemic hemodynamics by arterial baroreceptors. We now have measured the effect of 0.25 T SMF on microcirculation within cutaneous tissue of the rabbit ear lobe by the rabbit ear chamber (REC) method. Forty experimental runs (20 controls and 20 SMF) were carried out in eight different rabbits with an equal number of control and SMF experiments on each individual. Rabbits were sedated by pentobarbital sodium (5 mg/kg/h, i.v.) during the entire 80 min experiment. SMF was generated by four neodium‐iron‐boron alloy (Nd2‐Fe14‐B) magnets (15 × 25 × 30 mm, Neomax, PIP ‐ Tokyo Co., Ltd., Tokyo, Japan), positioned around the REC on the observing stage of an optical microscope. The direct intravital microscopic observation of the rabbit's ear microvascular net, along with simultaneous blood flow measurement by microphotoelectric plethysmography (MPPG), were performed PRE (20 min, baseline), DURING (40 min), and POST (20 min) magnetic field exposure. The control experiments were performed under the same conditions and according to the same time course, but without magnetic field. Data were analyzed comparing MPPG values and percent change from baseline in the same series, and between corresponding sections of control and SMF runs. In contrast to control series (100 ± 0.0%–90.0 ± 5.4%–87.7 ± 7.1%, PRE–EXPOSURE–POST), after magnetic field exposure we observed increased blood flow (100 ± 0.0%–117.8 ± 9.6%*–113.8 ± 14.0%, *P < 0.05) which gradually decreased after exposure cessation. We propose that long exposure of a high level nonuniform SMF probably modifies microcirculatory homeostasis through modulation of the local release of endothelial neurohumoral and paracrine factors that act directly on the smooth muscle of the vascular wall, presumably by affecting ion channels or second messenger systems. Bioelectromagnetics 23:224–229, 2002. © 2002 Wiley‐Liss, Inc.
Reactions of keratinocytes to in vitro millimeter wave exposure
Authors: Szabo Imre , Rojavin Mikhail A. , Rogers Thomas J. , Ziskin Marvin C. 
Published: August 2002

AbstractThe effects of millimeter waves (MW) on human keratinocytes were studied in vitro using the HaCaT keratinocyte cell line. MW‐induced modulation of keratinocyte function was studied in proliferation, adhesion, chemotaxis, and interleukin‐1β (IL‐1β) production assays. Spontaneous proliferation, adhesion to tissue culture plate, random migration, and IL‐8‐ and RANTES induced chemotaxis were not affected by exposure of cells to millimeter waves under the following conditions: frequency, 61.22 GHz; SAR, 770 W/kg; duration of exposure, 15–30 min. However, MW irradiation resulted in a modest but statistically significant increase in the intracellular level of IL‐1β. These data suggest that exposure of human skin (with keratinocytes being the major component of epidermis) to MW can cause activation of basal keratinocytes resulting in an elevated level of IL‐1β production. Bioelectromagnetics 22:358–364, 2001. © 2001 Wiley‐Liss, Inc.
Paradox of Bcl‐2 (and p53): why may apoptosis‐regulating proteins be irrelevant to cell death?
Authors: Blagosklonny Mikhail V. 
Published: August 2002

AbstractAlthough the Bcl‐2 family members and p53 are involved in the regulation of apoptosis, the status of apoptotic machinery (eg caspases) plays a major role in determining the mode and timing of cell death. If the apoptotic machinery is lost, inhibited, or intrinsically inactivated, the “death stars”, Bcl‐2 and p53, may become irrelevant to cell death. In this light, high levels of Bcl‐2 may indicate that downstream apoptotic pathways are still functional. This explains why Bcl‐2 overexpression can be a marker of chemosensitivity and favorable prognosis in certain cancers and why retention of wild‐type p53 may manifest inactivation of caspases in aggressive cancers. BioEssays 23:947–953, 2001. © 2001 John Wiley & Sons, Inc.
Near‐IR spectroscopic imaging for skin hydration: The long and the short of it
Authors: Attas E. Michael , Sowa Michael G. , Posthumus Trevor B. , Schattka Bernhard J. , Mantsch Henry H. , Zhang Shuliang L. 
Published: August 2002

AbstractNear‐IR spectroscopic methods have been developed to determine the degree of hydration of human skin in vivo. Noncontact reflectance spectroscopic imaging was used to investigate the distribution of skin moisture as a function of location. A human study in a clinical setting has generated quantitative data showing the effects of a drying agent and a moisturizer on delineated regions of the forearms of eight volunteers. Two digital imaging systems equipped with liquid‐crystal tunable filters were used to collect stacks of monochromatic images at 10‐nm intervals over the 650–1050 and 960–1700 nm wavelength bands. Synthetic images generated from measurements of water absorption band areas at three different near‐IR wavelengths (970, 1200, and 1450 nm) showed obvious differences in the apparent distribution of water in the skin. Changes resulting from the skin treatments were much more evident in the long‐wavelength images than in the short‐wavelength ones. The variable sensitivity of the method at different wavelengths has been interpreted as being the result of different penetration depths of the IR light used in the reflectance studies. © 2002 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 67: 96–106, 2002
Peroxidase activity of in vitro‐selected 2′‐amino RNAs
Authors: Teramoto Naozumi , Ichinari Hisashi , Kawazoe Naoki , Imanishi Yukio , Ito Yoshihiro 
Published: August 2002

AbstractPeroxidase activities of RNAs containing 2′‐amino groups, which were selected as aptamers binding to N‐methylmesoporphyrin IX, were investigated. Some clones promoted the oxidation reaction of 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) with hydrogen peroxide (H2O2) in the presence of iron(III)‐protoporphyrin (hemin), whereas others did not. Each of them had a different substrate specificity. One of the active clones promoted the oxidation of o‐dianisidine and β‐nicotinamide adenine dinucleotide reduced form (NADH) with H2O2 5 and 15 times faster than hemin only, respectively. On the other hand, one clone that was inactive on oxidation of ABTS exhibited the same level of activity on oxidation of o‐dianisidine as that shown by the clone active on ABTS but no activity on NADH. By in vitro selection, we can produce various types of peroxidase‐like non‐natural RNAs. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 75: 463–468, 2001.
The effect of dissolved oxygen (DO) concentration on the glycosylation of recombinant protein produced by the insect cell–baculovirus expression system
Authors: Zhang Fuming , Saarinen Mark A. , Itle Laura J. , Lang Sybil C. , Murhammer David W. , Linhardt Robert J. 
Published: August 2002

AbstractThe effect of dissolved oxygen concentration on human secreted alkaline phosphatase (SEAP) glycosylation by the insect cell–baculovirus expression system was investigated in a well‐controlled bioreactor. Oligomannose‐type N‐linked glycans (i.e., Man2 to Man6 and Man3F) were present in SEAP produced by Spodoptera frusiperda Sf‐9 (Sf‐9) and Trichoplusia ni BTI‐Tn‐5B1‐4 (Tn‐5B1‐4) insect cell lines. The relative amounts of the most highly processed glycans (i.e., Man3F and Man2 in the SEAP from Sf‐9 and Tn‐5B1‐4 cells, respectively) were significantly higher at 50% of air saturation than at either 10% or 190% of air saturation. That is, glycan processing was inhibited at both low and high dissolved oxygen concentrations. © 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 219–224, 2002.