bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of isocyanate production waste in the preparation of improved waterproofing bitumen
Authors: Singh B. , Tarannum Hina , Gupta M. 
Published: September 2003

AbstractWaste residue generated during the production of toluene diisocyanate was used as a modifier in making improved waterproofing bitumen. The waste particles were surface‐modified with stearic acid. Various bitumen blends based on untreated particles, surface‐treated particles, and a combination of an SBS elastomer and waste particles were prepared. The optimized blends were subjected to evaluate their response against temperature and frequency sweeps. It was observed that improvement of the softening point and reduction in penetration could be correlated with the blend morphology in terms of the compatibility between the waste particles and the bitumen. The increased glass transition temperature and satisfactory phase miscibility in the modified bitumen observed in MDSC and DMA traces supported these findings. The coefficient of linear thermal expansion of the modified bitumen was found to be 1.21 × 10−4/°C. The rheological studies revealed that time‐dependent properties of the modified bitumen were better in terms of its stiffness and elasticity than that of neat bitumen. The applicability of the Williams–Landel–Ferry (WLF) equation confirms the superior temperature‐dependent response of the modified systems over the control. It was noticed that stearate‐treated waste‐modified bitumen gives the best results in terms of a high complex modulus and a low phase angle. The newly formulated bituminous blend based on stearate‐treated waste meets the requirement of existing standard specifications for waterproofing felt. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1365–1377, 2003
Silicone elastomers with controlled surface composition using argon or hydrogen plasma treatment
Authors: Olander Björn , Wirsén Anders , Albertsson Ann‐Christine 
Published: September 2003

AbstractPlasma treatment of poly(dimethyl siloxane) (PDMS) leads to changes in the surface composition that can be followed by X‐ray photoelectron spectroscopy (XPS). Prolonged plasma treatment in argon or hydrogen leads to an increase in oxygen, a decrease in carbon, and only minor changes in the silicon content. The extent of the change in elemental composition is dependent on the plasma conditions (e.g., the power and pressure during the treatment). We have determined how these parameters influence the surface composition of PDMS exposed to argon and hydrogen microwave plasma as a function of treatment time. A model has been developed describing the extent of change in surface composition under different plasma conditions. The power had a large impact on the rate of change in elemental surface composition, whereas the pressure had only a minor influence. We show that the rate of change in elemental composition can be described by one factor common for all treatments and one factor specific for each plasma condition of power, pressure, and gas. Using this model we can determine the plasma parameters and treatment time to obtain any desired extent of surface modification. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1378–1383, 2003
Preparation and characterization of chitosan/Cu(II) affinity membrane for urea adsorption
Authors: Liu Jiahao , Chen Xin , Shao Zhengzhong , Zhou Ping 
Published: September 2003

AbstractWe used silica particles as a porogen to prepare macroporous chitosan membranes and subsequently prepared macroporous chitosan/Cu(II) affinity membranes for urea adsorption. The morphology, porosity, Cu(II) adsorption capacity, and swelling ratio of the macroporous membrane were measured. SEM photographs show the pores in the membrane dispersed uniformly, a feature that didn't change much after the adsorption of Cu(II). The porosity of the membrane had a maximum value when the silica/chitosan ratio was about 12. The Cu(II) adsorption capacity in the membrane leveled off when the initial concentration of CuSO4 solution exceeded 5 × 10−2 mol/L. The macroporous chitosan/Cu(II) affinity membrane was successfully used for urea adsorption. The maximum urea adsorption capacity was 78.8 mg/g membrane, which indicates that the membrane has a great potential for hemodialysis for urea removal. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1108–1112, 2003
Preparation and characteristics of poly(propylene glycol) and poly(acrylic acid) interpenetrating polymer network hydrogels
Authors: Kim Seon Jeong , Lee Ki Jung , Kim In Young , An Kay Hyeok , Kim Sun I. 
Published: September 2003

AbstractInterpenetrating polymer network (IPN) hydrogels based on poly(propylene glycol) diacrylate macromer and poly(acrylic acid) (PAAc) were prepared by UV irradiation and characterized by swelling in water. The swelling behavior of these IPNs was analyzed in buffer solution at various temperatures. Swelling ratios of all IPNs were relatively high and showed reasonable sensitivity to temperature. Hydrogels showed both positive and negative swelling behavior depending on PAAc content. PA22 and PA13 showed positive and PA31 showed negative temperature‐sensitive swelling behavior. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1384–1388, 2003
Water sorption of poly(vinyl alcohol)/ poly(diallyldimethylammonium chloride) interpenetrating polymer network hydrogels
Authors: Kim Seon Jeong , Yoon Seoung Gil , Lee Young Moo , An Kay Hyeok , Kim Sun I. 
Published: September 2003

AbstractTemperature‐responsive interpenetrating polymer network (IPN) hydrogels constructed with poly(vinyl alcohol) and poly(diallyldimethylammonium chloride) using the sequential IPN method were studied. The characteristics of IPN hydrogels were investigated using the dynamic vapor sorption system. IPN hydrogels exhibited a relatively high sorption ratio, 180–360% at room temperature. The sorption ratio of hydrogels depended on temperature. Diffusion coefficients were calculated according to the Fickian Law at several temperatures. The apparent activation energy was 5.43 kJ mol−1, which corresponds to typical diffusion processes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1389–1392, 2003
Study of the thermal stability of glucose oxidase in the presence of water‐soluble polymers
Authors: Godjevargova T. , Vasileva N. , Letskovska Zl. 
Published: September 2003

AbstractThe thermal stability of glucose oxidase (GOD) in solutions containing water‐soluble hydrolyzed polyacrylonitrile (HPAN) and polyoxyethylene (POE) was studied as a function of time and temperature between 28 and 60°C. The results were compared with the thermal stability of GOD in solutions without polymers. The polymers studied were found to increase the enzyme thermal stability. The influence of the concentration of the water‐soluble polymers on enzyme thermal stability was also studied. The best protection effect on enzyme thermal stability had 3 wt % solution of HPAN and 1 wt % solution of polyoxyethylene. Solutions with higher concentrations led to a quick deactivation of the enzyme. It was proved that the effect of 3 wt % HPAN solution was stronger than the effect of 1 wt % POE (59.0 versus 52.0%). The thermal transition of the enzyme was studied in both the presence and the absence of HPAN by DSC. The melting temperature of GOD in the presence of HPAN was shifted to an 11°C higher value. This sustained the supposition that HPAN increases the thermostability of GOD. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1393–1397, 2003
Preparation of conducting composites of polypyrrole using supercritical carbon dioxide
Authors: Abbett Kimberly F. , Teja Amyn S. , Kowalik Janusz , Tolbert Laren 
Published: September 2003

AbstractSupercritical carbon dioxide, saturated with pyrrole, was brought into contact with oxidant‐impregnated films of poly(chlorotrifluoroethylene) (PCTFE), crosslinked poly(dimethylsiloxane) (PDMS), poly(methyl methacrylate) (PMMA), and porous crosslinked polystyrene (PS) in order to form conducting composites via the in situ polymerization of pyrrole. The two nonporous hosts—PCTFE and crosslinked PDMS—did not form conducting composites with polypyrrole (PPy). On the other hand, the electrical conductivity of the PPy composites with carbon dioxide‐swollen PMMA and porous PS ranged from 1.0 × 10−4 S/cm to 3.0 × 10−5 S/cm. In these two cases, the level of pyrrole polymerized on the surface or in the pores of the host polymer was sufficient to attain the interconnected conducting polymer networks necessary for electrical conductivity. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1113–1116, 2003
Antimycobacterial and Antifungal Isosters of Salicylamides
Authors: Waisser Karel , Pešina Milan , Holý Pavel , Pour Milan , Bureš Otakar , Kuneš Jiší , Klimešová Všra , Buchta Vladimír , Kubanová Petra , Kaustová Jarmila 
Published: September 2003

AbstractA set of 40 derivatives of 3‐hydroxypicolinic acid and 2‐sulfanylbenzoic acid, isosteric to salicylanilides was synthesized. The compounds were evaluated for in vitro activity against Mycobacterium tuberculosis, Mycobacterium kansasii and Mycobacterium avium, Candida albicans, Candida tropicalis, Candida krusei, Candida glabrata, Trichosporon beigelii, Aspergillus fumigatus, Absidia corymbifera, Trichophyton mentagrophytes and Microsporum gypseum. Structure‐activity relationships of antimycobacterial activity and antifungal activity against T. mentagrophytes and M. gypseum were analyzed by the Free‐Wilson method. An increase in antimycobacterial activity was observed only for the sulfanylbenzoic acid derivatives, especially those with the benzyl moiety. The antifungal activity was not significant.
3‐Alkyl‐ and 3‐Aryl‐(7‐oxo‐7H‐furo[3, 2‐g]chromen‐5‐yl)alkanoic Acids as Inhibitors of Leukotriene B4 Biosynthesis
Authors: Körner Paul 
Published: September 2003

AbstractThe synthesis and biological properties of 3‐alkyl‐and 3‐aryl‐(7‐oxo‐7H‐furo [3, 2‐g]chromen‐5‐yl)alkanoic acids are described. The compounds were evaluated for their ability to inhibit soybean 15‐lipoxygenase (15‐LO) and the production of leukotriene B4 (LTB4) in bovine polymorphonuclear leukocytes. The furocoumarins were further investigated for their lipophilicity and their capacity to photobleach N, N‐dimethyl‐p‐nitrosoaniline (RNO) after irradiation with UVA light. The synthesised furocoumarins showed only a moderate ability to inhibit the 15‐LO and the production of LT B4. The 3‐alkyl substituted furocoumarins had a higher capacity to photobleach RNO than then the 3‐aryl substituted furocoumarinso. The inhibitory activity of the newcompounds was quite modest in comparison to other known inhibitors of 15‐LO and LTB4 production. Nevertheless, they may provide the basis for the development of more potent antiinflammatory potential photoreactive furocoumarins.
Structure‐Activity Studies of Novel Amidine Analogues of Chlorambucil: Correlation of Cytotoxic Activity with DNA‐Binding Affinity and Topoisomerase II Inhibition
Authors: Bielawska Anna , Bielawski Krzysztof , Wołczyński Sławomir , Anchim Tomasz 
Published: September 2003

AbstractA series of amidine analogues of chlorambucil (9—12), where 5‐[4‐(N‐alkylamidino)phenyl]‐2‐furancarboxamide and the chlorambucil moiety are linked by a NH(CH2)2NH chain, was synthesized and their cytotoxicity has been tested against the growth of human breast cancer MCF‐7 cells. Evaluation of the cytotoxicity of compounds 9—12 employing a MTT assay and inhibition of [3H]thymidine incorporation into DNA demonstrated that these conjugates were more active than chlorambucil. Data from the ethidium displacement assay indicated that these compounds bind in the minor groove of DNA and show moderate specificity for AT base pairs. Compounds 9—12 were potent topoisomerase II inhibitors, with 50% inhibitory concentrations (IC50)ranging from 10 to 40 μM. The cytotoxicity of the compounds 9—12 correlates with their DNA‐binding affinities and their relative potency as topoisomerase II inhibitors. Altogether, these data suggest (i) that the cytotoxic activity of compounds 9—12 may be due to the combined effects of alkylation, DNA‐minor groove binding, and (ii) that N‐(2‐aminoethyl)‐5‐(4‐N‐alkylamidinophenyl)‐2‐furancarboxamides (5—8) ligands are suitable linkers that favors DNA targeting by chlorambucil derivatives.
Studies on Novel 7‐Acyl‐5‐chloro‐2‐oxo‐3H‐benzoxazole Derivatives as Potential Analgesic and Anti‐Inflammatory Agents
Authors: Ünlü Serdar , Baytas Sultan Nacak , Kupeli Esra , Yesilada Erdem 
Published: September 2003

AbstractIn this study, a series of (7‐acyl‐5‐chloro‐2‐oxo‐3H‐benzoxazol‐3‐yl)alkanoic acid derivatives were synthesized and evaluated for their analgesic and anti‐inflammatory activities by using the p‐benzoquinone‐induced writhing test and the carrageenan hind paw edema model, respectively. Acetic acid‐induced peritoneal capillary permeability test and serotonin‐induced hind paw edema test were also employed for the most active compounds. The test results indicated that (7‐acyl‐2‐oxo‐3H‐benzoxazol‐3‐yl)alkanoic acids (Compounds 6 a—c, 8 a—c, 10 a—c) were equally or more potent analgesic and anti‐inflammatory agents than aspirin and indomethacin respectively. The compounds 8a and 8c, but not 8b have the longest carbon chain on alkanoic acid moiety did not induce gastric lesion in mice.
New Cyanopeptide‐Derived Low Molecular Weight Inhibitors of trypsin‐like Serine Proteases
Authors: Radau Gregor , Schermuly Sonja , Fritsche Alexandra 
Published: September 2003

AbstractThis paper deals with the design, syntheses, and inhibition tests of new low molecular weight thrombin inhibitors utilizing cyanopeptides, the secondary metabolites of cyanobacteria with interesting biological activities, as new lead structures. Starting with aeruginosin 98‐B (1) as a lead structure, we have developed and synthesised new, selective acting inhibitors of serine proteases (RA‐1005 and RA‐1009, which are suitable targets for further structure‐activity studies.
Novel High Energy Intermediate Analogues with a Triazasterol Structure as Potential Ergosterol Biosynthesis Inhibitors IV: Antimicrobial Activity of Mono‐, Bi‐, and Tricyclic 8, 13, 15‐Triazasteroid Analogues Including the Synthesis of Novel 4‐Alkylamino‐ and 4‐Alkenylamino‐9‐hydroxypyrimidoisoquinolines
Authors: Gößnitzer Edith , Punkenhofer Asbjörn , Ryder Neil S. 
Published: September 2003

Abstract4‐Alkylamino‐and 4‐alkenylamino‐9‐hydroxy‐1, 6, 7, 11b‐tetrahydro‐2H‐pyrimido[4, 3‐a]isoquinolines were designed as inhibitory tricyclic triaza‐analogues of carbocationic high energy intermediates (HEI) of enzymes involved in fungal ergosterol biosynthesis. Various routes for effective synthesis of 9‐hydroxypyrimidoisoquinolines from 9‐methoxythiones were investigated. The ether cleavage of 9‐methoxy‐pyrimidoisoquinolines, a key step in the synthesis, was carried out using various protocols. The structures of the obtained 9‐hydroxy compounds were confirmed using homo‐ and hetero‐nuclear correlated 1D and 2D NMR experiments. In vitro antifungal susceptibility tests of the alkylaminohydroxypyrimidoisoquinolines revealed weak to good antimycotic effects. The maximum antifungal efficacy was found for 4‐[(3R)‐6‐isopropyl‐3‐methyl‐6‐heptenylamino]‐9‐hydroxypyrimidoisoquinoline. Furthermore, the in vitro activities of the newly synthezised 9‐hydroxypyrimidoisoquinolines and of a series of prepared 8, 13, 15‐triazasteroid analogues (N‐alkyl‐N′‐(phenethyl‐ and cyclohexenylethyl)guanidines, N2 ‐and N2, 4‐substituted imidazolin‐2‐amines, and N4‐alkylaminopyrimidoisoquinolines) against representatives of gram‐positive and gram‐negative bacteria were investigated. The compounds showed significant antibacterial effects against gram‐positive bacteria.
Characterization of the Biochemical Effects of New 1, 8‐Naphthyridine Derivatives, β‐Receptor Antagonists, in Ventricular Myocytes
Authors: Al jamal Jalal A. , Badawneh Muwaffag 
Published: September 2003

AbstractNovel derivatives of 1, 8‐naphthyridine were synthesized from 7‐amino‐2‐hydroxy‐4‐morpholinomethyl‐1, 8‐naphthyridine. The ability of the synthesized compounds to inhibit isoproterenol(ISO)‐induced phosphorylation of phospholamban (PLB) was assessed. Their ability to block both β1 and β2 receptors almost completely abolished all ISO effects on phosphorylation of PLB. Analogues with either a 7‐hydroxy‐2‐N‐ethoxycarbonylpiperazine or a 7‐hydroxy‐2‐piperazine substituent, designated as 6 and 9 respectively, showed a higher affinity for β1 receptor than that of the methoxy derivatives 12 and 13. However, treatment with 30 μM 9 and 1mM 13 lead to comparable levels of PLB phosphorylation. The reduction to 6‐amino derivatives 10 and 17 led to compounds possessing β2 receptor blocking properties. The ability of the synthesized compounds to inhibit forskolin‐stimulated cAMP production was also studied. Together, these results suggest that the 1, 8‐naphthyridine parent structure can be modified, to produce compounds with increased activity whose effect in rat appears to be more clearly related to antagonism of β1‐rather than β2‐adrenergic receptors.
Overlap in bibliographic databases
Authors: Hood William W. , Wilson Concepción S. 
Published: September 2003

AbstractBibliographic databases contain surrogates to a particular subset of the complete set of literature; some databases are very narrow in their scope, while others are multidisciplinary. These databases overlap in their coverage of the literature to a greater or lesser extent. The topic of Fuzzy Set Theory is examined to determine the overlap of coverage in the databases that index this topic. It was found that about 63% of records in the data set are unique to only one database, and the remaining 37% are duplicated in from two to 12 different databases. The overlap distribution is found to conform to a Lotka‐type plot. The records with maximum overlap are identified; however, further work is needed to determine the significance of the high level of overlap in these records. The unique records are plotted using a Bradford‐type form of data presentation and are found to conform (visually) to a hyperbolic distribution. The extent and causes of intra‐database duplication (records duplicated in the one database) are also examined. Finally, the overlap in the top databases in the dataset were examined, and a high correlation was found between overlapping records, and overlapping DIALOG OneSearch categories.
The experience of libraries across time: Thematic analysis of undergraduate recollections of library experiences
Authors: Kracker Jacqueline , Pollio Howard R. 
Published: September 2003

AbstractTo understand the human experience of libraries and the implications this understanding has for library use and service, education, and design, 118 undergraduate students were asked to list three personally memorable incidents concerning library use. Following this, they were asked to write a short narrative of one of these experiences. Incidents reported by participants ranged from preschool to college age, and content analysis indicated that a majority took place at two or more grade levels, sometimes as early as the participant's first (preschool) visit to a library. Phenomenological analysis of individual narratives produced a thematic structure for each of the four grade levels represented in the data: elementary school and younger, middle school, high school, and college/adult. Themes common across all four levels include Atmosphere, Size and Abundance, Organization/Rules and Their Effects on Me, and What I Do in the Library. A theme of Memories was unique to narratives that took place during elementary and younger age levels. Although all remaining themes were noted across age levels, the relative importance of various themes and subthemes was different at different ages. Implications of the thematic structure for library practice are discussed.
Bibliomining for automated collection development in a digital library setting: Using data mining to discover Web‐based scholarly research works
Authors: Nicholson Scott 
Published: September 2003

AbstractThis research creates an intelligent agent for automated collection development in a digital library setting. It uses a predictive model based on facets of each Web page to select scholarly works. The criteria came from the academic library selection literature, and a Delphi study was used to refine the list to 41 criteria. A Perl program was designed to analyze a Web page for each criterion and applied to a large collection of scholarly and nonscholarly Web pages. Bibliomining, or data mining for libraries, was then used to create different classification models. Four techniques were used: logistic regression, nonparametric discriminant analysis, classification trees, and neural networks. Accuracy and return were used to judge the effectiveness of each model on test datasets. In addition, a set of problematic pages that were difficult to classify because of their similarity to scholarly research was gathered and classified using the models. The resulting models could be used in the selection process to automatically create a digital library of Web‐based scholarly research works. In addition, the technique can be extended to create a digital library of any type of structured electronic information.
New knowledge management systems: The implications for data discovery, collection development, and the changing role of the librarian
Authors: Stern David 
Published: September 2003

AbstractThe papers presented at the 2002 Tri‐Society Symposium on Chemical Information highlight questions we should consider as we develop new paradigms for information storage and retrieval systems. These new knowledge management systems will require novel approaches for data discovery, collection development, and the changing role of the librarian. This introductory essay discusses new and challenging integrated tools for data manipulation, the confusing and embryonic differential pricing and package deals for journal materials, and the changing role of the librarian in this rapidly transforming industry.
Making the transition from print to electronic serial collections: A new model for academic chemistry libraries?
Authors: Chrzastowski Tina E. 
Published: September 2003

AbstractA “new model” academic chemistry library is proposed at the University of Illinois at Urbana‐Champaign (UIUC) in which primary access to journals is electronic, replacing traditional print access, binding, and shelving. Print journals will continue to be purchased and archived unbound in a remote storage facility following unbound display and access for twelve months. The new model, initially proposed by administrative chemistry faculty, was assessed in a feasibility study which looked at the stability, quantity, and quality of electronic journals; it also included a survey of chemistry faculty, a review of internal management data, and an analysis of use of chemistry journals, both print and electronic. The feasibility study found support for the model in every area, but with a few caution flags and speed bumps predicted along the way.
Changing use patterns of print journals in the digital age: Impacts of electronic equivalents on print chemistry journal use
Authors: Vaughan K.T.L. 
Published: September 2003

AbstractLittle data are available that can help librarians solve issues surrounding print versus online journals management, including ascertaining when print journals are no longer needed. This study examines the short‐term effects of online availability on the use of print chemistry journals. The Duke University Chemistry Library gained access to Elsevier titles via ScienceDirect in February 2000. By comparing reshelving data for the print journals from 1999, 2000, and 2001, this study identifies the short‐term changes in journals use that can be attributed to the introduction of ScienceDirect. In the first two years after ScienceDirect was introduced, use of print journals nearly halved. The diminished use of the print collection has important implications for collection management in sci‐tech libraries.