bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solution thermodynamics of poly(ethylene glycol)/water systems
Authors: Özdemir Cemile , Güner Ali 
Published: April 2006

AbstractThe unperturbed molecular dimensions of poly(ethylene glycol) (PEG) samples (of different molecular weights) have been evaluated in aqueous solutions from viscosity measurements at 25, 30, 35, and 40°C. The unperturbed dimension, Kθ, has been determined from extrapolation methods, i.e., Kurata–Stockmayer–Fixman (KSF), Inagaki–Suzuki–Kurata (ISK), and Berry equations. The hydrodynamic expansion factor, αη, as well as the unperturbed root‐mean‐square end‐to‐end distance, 〈r2〉, found for the system indicated that the polymer coils contract as the temperature is raised from 25 to 40°C. The long‐range interaction (excluded volume) parameter, B, was also evaluated and a significant decrease was found for the PEG/water system between 25 and 40°C. The theta temperatures, θ, were obtained from the temperature dependence of (1/2 − χ) and the second virial coefficient was detected in the temperature interval of 25–40°C for the system and quite a good agreement with the calculated values evaluated via extrapolation and interpolation methods was observed. The thermodynamic interaction parameter χ was evaluated through the sum of the individual values of enthalpy and entropy dilution parameters, χH and χS, for PEG samples. All the unperturbed molecular dimensions of PEG/water system were calculated and compared according to Mw and Mn values of PEG samples. Calculated values were interpreted mainly on the basis of hydrogen‐bond formation between polymer segments and PEG‐water molecules in solution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 203–216, 2006
Correlating miscibility of PVC/PMMA blend with polymer chain orientation
Authors: Deshpande V. D. , Singh Umesh 
Published: April 2006

AbstractBlends of poly (vinyl chloride) (PVC) and poly (methyl methacrylate) (PMMA) with varying concentrations of the polymers were prepared in a film form by standard solution casting method, using methyl ethyl ketone (MEK) as a common solvent. The miscibility of the blend was studied by dynamic mechanical analysis. The chain orientation behaviors of PVC and PMMA in the stretched blend films were studied by infrared dichroism method. Up to 60 wt % PVC concentration in the blend, PVC showed negative values for orientation function whereas PMMA showed independent positive values for its orientation function. On further increasing PVC concentration in the blend, the orientation function of PVC flipped to positive values, and both PVC and PMMA showed same magnitude and trend in orientation behavior. The chain orientation behavior of individual polymers in the immiscible compositions of the blend was observed to be independent, while there was a high degree of cooperation for chain orientation in the miscible composition. Change in the miscibility of the blend was simultaneously accompanied by conformational changes in PVC. The change in orientation behavior is interpreted in terms of curling of polymer chains in the immiscible phase. The polymer chain curling hypothesis used here is applicable independent of the type of polymers in the blend. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 624–630, 2006
Preparation of porous thin films of a partially aliphatic polyimide
Authors: Chung Chan‐Moon , Lee Ju‐Ho , Cho Sung‐Youl , Kim Joong‐Gon , Moon Sung‐Yun 
Published: April 2006

AbstractA thermally labile polymer, poly(propylene glycol), was modified to obtain PPG having an amino end group. PPG was incorporated into a partially aliphatic polyimide based on an alicyclic dianhydride, and this afforded triblock copolymers containing various amounts of PPG blocks. The thermal properties of the copolymers were investigated by thermogravimetric analysis and differential scanning calorimetry. The thermal decomposition of the PPG block in the copolymers was carried out at 240°C under various pressures to obtain porous polyimide films. The pores remained during the thermolysis under a reduced pressure of 710 mmHg, whereas they collapsed under (near) atmospheric pressure. The pore size increased as the amount of the PPG block in the copolymers increased. The dielectric constants of the porous polyimides varied from 2.60 to 2.42 with the original copolymer composition. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 532–538, 2006
Orientation and property correlations for LLDPE blown films
Authors: Chen H. Y. , Bishop M. T. , Landes B. G. , Chum S. P. 
Published: April 2006

AbstractThe orientation and property correlations of biaxially oriented polyethylene (PE) blown films have been studied. A linear low density polyethylene (LLDPE) (DOWLEX™2045A) was used to fabricate films at different conditions with blow up ratio, die gap, and frost line height as the variables. The White‐Spruiell orientation factors of crystal unit cells, amorphous chains, and Herman's orientation factors of lamellae were determined from wide‐angle X‐ray diffraction pole figure, birefringence, and small angle X‐ray scattering (SAXS). A general orientation pattern with the crystal unit cella‐axis preferentially oriented to MD,b‐axis to TD, lamellae stacking along the MD, and amorphous chains preferentially to the MD has been found for all films in this study. A correlation between the orientation of each element of the morphology hierarchy has been revealed. Key mechanical properties including dart impact and Elmendorf tear strength in both MD and TD have been determined. Good correlation has been found among these properties. Most importantly, these properties have excellent correlation to the orientation. These correlations have been linked to underlying morphology and microdeformation mechanisms. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 898–907, 2006
Crosslinked poly(glycidyl methacrylate)‐based resin for removal of mercury from aqueous solutions
Authors: Şenkal B. Filiz , Yavuz Erdem 
Published: April 2006

AbstractGlycidyl methacrylate–based resin crosslinked beads with acetamide functions were demonstrated to be efficient in the removal of mercury. Beaded polymer supports were prepared by suspension polymerization of glycidyl methacrylate (0.9 mol) and ethylene glycol dimethacrylate (0.1 mol). The resulting copolymer beads were modified through epoxy functions in two steps: (1) by treatment with excess dibutyl amine and (2) by subsequent reaction with chloroacetamide. The resulting polymer resin, which had a chloroacetamide content of 2.5 mmol/g, was effective in extracting mercury from aqueous solutions. The mercury sorption capacity was around 2.2 mmol/g in nonbuffered conditions. Experiments performed in identical conditions with several metal ions revealed that Cd(II), Pb(II), Zn(II), and Fe(III) ions also were extractable in low quantities (0.2–0.8 mmol/g). The sorbed mercury could be eluted by repeated treatment with hot acetic acid without hydrolysis of the amide groups. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 348–352, 2006
Reactive processing and evaluation of butadiene–styrene copolymer/polyaniline conductive blends
Authors: Martins Cristiane Reis , Faez Roselena , Rezende Mirabel Cerqueira , De Paoli Marco A. 
Published: April 2006

AbstractBlending is an important way to obtain materials based on intrinsically conductive polymers and conventional plastics and rubber materials. Much research has been carried out to determine the best performance of materials be used for electrostatic dissipation and electromagnetic interference shielding. Mechanical mixing, codissolution, and in situ polymerization have been used to prepare these materials. The method used depends on the host polymer and its thermal stability and acid attack resistance. Homogeneity and miscibility are properties that should be controlled during blend preparation. In this study, we prepared a conductive thermoplastic elastomer material based on butadiene–styrene copolymer (SBR) and polyaniline (PANI) doped with dodecylbenzene sulfonic acid (DBSA) and poly(styrene sulfonic acid) (PSS). PSS also acted as compatibilizer between PANI and SBR. PANI was doped by reactive processing with DBSA and PSS to produce the conductive complex PANI–DBSA–PSS. This complex was mixed with 90, 70, and 50% (w/w) SBR in a counterrotatory internal mixer. Conductivity tests, swelling studies, thermal analysis, and mechanical property and reflectivity testing were done, and the results show a strong dependence on PANI concentration and the ratio between PANI–DBSA and PSS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 681–685, 2006
Gas permeability and permselectivity of plasma‐treated polyethylene membranes
Authors: Nakata M. , Kumazawa H. 
Published: April 2006

AbstractThe effects of NH3‐plasma and N2‐plasma treatments on rubbery polyethylene (PE) membranes on the permeation behavior for carbon dioxide (CO2), O2, and N2 were investigated with permeability measurements. The NH3‐plasma and N2‐plasma treatments on PE membranes increased both the permeation coefficient for CO2 and the ideal separation factor for CO2 with respect to N2. For O2 transport, both the permeation coefficient for O2 and the ideal separation factor for O2 with respect to N2 were increased. NH3‐plasma and N2‐plasma treatments on polymer membranes possibly bring about an augmentation of permeability and permselectivity simultaneously. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 383–387, 2006
Low‐density polyethylene/plasticized tapioca starch blends with the low‐density polyethylene functionalized with maleate ester: Mechanical and thermal properties
Authors: Girija B. G. , Sailaja R. R. N. 
Published: April 2006

AbstractIn this study, the mechanical and thermal properties of low‐density polyethylene (LDPE)/thermoplastic tapioca starch blends were determined with LDPE‐g‐dibutyl maleate as the compatibilizer. Mechanical testing for the evaluation of the impact strength and tensile properties was carried our as per standard ASTM methods. Thermogravimetric analysis and differential scanning calorimetry were also used to assess the thermal degradation of the blends. Scanning electron micrographs were used to analyze fracture and blend morphologies. The results show significant improvement in the mechanical properties due to the addition of the compatibilizer, which effectively linked the two immiscible blend components. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1109–1120, 2006
Dynamic mold surface temperature control using induction heating and its effects on the surface appearance of weld line
Authors: Chen Shia‐Chung , Jong Wen‐Ren , Chang Jen‐An 
Published: April 2006

AbstractElectromagnetic induction heating combined with coolant cooling is used to achieve dynamic mold surface temperature control. A simulation tool was also developed by integration of both thermal and electromagnetic analysis modules of ANSYS, and capability and accuracy were verified experimentally. To evaluate the feasibility and efficiency of induction heating on the mold surface temperature control, a mold plate (roughly about an inset size of cellular phone housing) with four cooling channels was utilized for two demo experiments with varying mold surface temperature between 110 and 180°C, and 110 and 200°C, respectively. During induction heating/cooling, it takes 4 s to increase mold surface temperature from 110 to 200°C and 21 s for mold surface to return to 110°C. The mold plate surface temperature can be raised at about 22.5°C and cooled down at 4.3°C/s within the aforementioned temperature range. Mold plate temperature distribution exhibits good uniformity as well in all stages of the heating/cooling process. Finally, mold surface temperature of a double‐gated tensile test part mold was induction heated to above glass transition temperature for few seconds prior to melt injection. The surface mark of weld line was eliminated, and the associated weld line strength enhanced. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1174–1180, 2006
Electrodes with High Power and High Capacity for Rechargeable Lithium Batteries.
Authors: Kang Kisuk , Meng Ying Shirley , Breger Julien , Grey Clare P. , Ceder Gerbrand 
Published: April 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Microwave‐Assisted, Solvent‐Free Bischler Indole Synthesis.
Authors: Sridharan Vellaisamy , Perumal Subbu , Avendano Carmen , Menendez J. Carlos 
Published: April 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Is long‐term humoral immunity in the mucosa provided by long‐lived plasma cells? A question still open
Authors: Hiepe Falk , Radbruch Andreas 
Published: April 2006

AbstractThe biology of antibody‐secreting cells is still a matter of controversial discussion. One of the key questions is how the migration and lifespan of antibody‐secreting cells is linked to their generation. A paper in this issue of the European Journal of Immunology provides further information on the generation of long‐term mucosal immune responses; however, the study leaves many questions unanswered as discussed in this brief Commentary.See accompanying article http://dx.doi.ORG/10.1002/eji.200535493
Regulation of osteoclastogenesis by gap junction communication
Authors: Matemba Stephen F. , Lie Anita , Ransjö Maria 
Published: April 2006

AbstractReceptor activator of NF‐κB ligand (RANKL) is crucial in osteoclastogenesis but signaling events involved in osteoclast differentiation are far from complete and other signals may play a role in osteoclastogenesis. A more direct pathway for cellular crosstalk is provided by gap junction intercellular channel, which allows adjacent cells to exchange second messengers, ions, and cellular metabolites. Here we have investigated the role of gap junction communication in osteoclastogenesis in mouse bone marrow cultures. Immunoreactive sites for the gap junction protein connexin 43 (Cx43) were detected in the marrow stromal cells and in mature osteoclasts. Carbenoxolone (CBX) functionally blocked gap junction communication as demonstrated by a scrape loading Lucifer Yellow dye transfer technique. CBX caused a dose‐dependent inhibition (significant ≥ 90 µM) of the number of tartrate‐resistant acid phosphatase (TRAP)‐positive multinucleated cells formed in 7‐ to 8‐day marrow cultures stimulated by parathyroid hormone (PTH; 10 nM) or forskolin (FSK; 1 µM). Furthermore, CBX (100 µM) significantly inhibited prostaglandin E2 (PGE2; 10 µM) and 1,25(OH)2‐vitamin D3 stimulated osteoclast differentiation in the mouse bone marrow cultures. Consequently, quantitative real‐time polymerase chain reaction (PCR) analysis demonstrated that CBX downregulated the expression of osteoclast phenotypic markers, but without having any significant effects on RANK, RANKL, and osteoprotegerin (OPG) mRNA expression. However, the results demonstrated that CBX significantly inhibits RANKL‐stimulated (100 ng/ml) osteoclastogenesis in the mouse bone marrow cultures. Taken together, our results suggests that gap junctional diffusion of messenger molecules interacts with signaling pathways downstream RANKL in osteoclast differentiation. Further studies are required to define the precise mechanisms and molecular targets involved. J. Cell. Biochem. 99: 528–537, 2006. © 2006 Wiley‐Liss, Inc.
Pathology of lumbar nerve root compression: Parts 1 and 2
Authors: Kobayashi Shigeru , Yoshizawa Hidezo , Yamada Shuuichi 
Published: April 2006

AbstractThe original articles to which this Erratum refers were published in Journal of Orthopaedic Research 22, 2004, 170–179 and 180–188 by Elsevier Ltd.
Reduced expression of the Connexin26 gene and its aberrant DNA methylation in rat lung adenocarcinomas induced by N‐nitrosobis(2‐Hydroxypropyl)amine
Authors: Shimizu Kyoko , Shimoichi Yozo , Hinotsume Daisei , Itsuzaki Yumi , Fujii Hiromasa , Honoki Kanya , Tsujiuchi Toshifumi 
Published: April 2006

AbstractGap junctions are mediated by intercellular channels that connect adjacent cells and are composed of Connexin (Cx) proteins. A member of the Cx family, Cx26 is considered a potential tumor suppressor in several cancers. The expression of Cx26 gene and its methylation status in rat lung adenocarcinomas induced by N‐nitrosobis(2‐hydroxypropyl)amine (BHP) were investigated. Six‐wk‐old male Wistar rats were given 2,000 ppm BHP in their drinking water for 12 wk and maintained without further treatment until they were sacrificed at 25 wk. A total of nine lung adenocarcinomas were obtained and total RNA was extracted to assess expression by real‐time quantitative reverse transcription (RT)‐polymerase chain reaction (PCR). Five out of nine adenocarcinomas showed reduced expression compared with normal lung tissue. We next performed a bisulfite sequence analysis to measure the methylation status of the 5′ upstream region of the Cx26 gene in two normal lung tissues and five lung adenocarcinomas that showed reduced expression of Cx26. All five adenocarcinomas were highly methylated in the 5′ upstream region, while the two normal lung tissues were unmethylated. This suggests that aberrant methylation of the Cx26 gene may be involved in the development of lung adenocarcinomas induced by BHP in rats. © 2006 Wiley‐Liss, Inc.
Prostate cancer chemoprevention by silibinin: Bench to bedside
Authors: Singh Rana P. , Agarwal Rajesh 
Published: April 2006

AbstractProstate cancer (PCA) is the most invasive malignancy and second leading cause of cancer deaths in American males. One approach to reduce PCA incidence, growth and metastasis is prevention and intervention targeted towards mitogenic and survival signaling and cell‐cycle regulation. This approach is based on the rationale that overexpression of receptor tyrosine kinases (RTKs) and/or non‐receptor tyrosine kinases leads to persistent autocrine stimulation of malignant cells for deregulated cell‐cycle progression and uncontrolled growth. PCA progression has also been associated with transition from a paracrine to an autocrine relationship between receptors and growth ligands as this malignancy progresses to an advanced androgen‐independent aggressive stage. Together, these studies suggest that targeting RTK‐mediated signaling pathways along with cell‐cycle regulators could be a practical and translational approach for PCA prevention and intervention. Here, we provide evidence that a naturally occurring nontoxic flavanoid, silibinin, targets the epidermal growth factor receptor (EGFR), insulin‐like growth factor‐1 receptor (IGF‐1R) and NF‐κB (nuclear factor‐kappa B) pathways in PCA. Furthermore, it modulates cell‐cycle regulators, including cyclin‐dependent kinases (CDKs), Cip/Kip and cyclins for its anticancer efficacy against PCA. Silibinin inhibits growth of PCA cells from human, mouse, and rat origins, and also suppresses human prostate tumor xenograft growth in nude mice. Silibinin also inhibits PCA growth in the transgenic adenocarcinoma of mouse prostate (TRAMP) mouse model. Now, silibinin has been entered into phase I/II clinical trials in human PCA patients where preliminary observations were suggestive of its further study in a larger base of the patient population. © 2006 Wiley‐Liss, Inc.
External urethral sphincter activity in a rat model of pudendal nerve injury
Authors: Peng Chih‐Wei , Chen Jia‐Jin Jason , Chang Hui‐Yi , de Groat William C. , Cheng Chen‐Li 
Published: April 2006

AbstractAimsPudendal nerve injury in the rat has been a useful animal model for studying stress urinary incontinence (SUI). However, the effect of pudendal nerve injury on activity of the external urethral sphincter (EUS) is relatively unexplored. The aims of this study were to examine voiding and the EUS electromyogram (EMG) in a durable SUI model in rats with bilateral or unilateral pudendal nerve transections. In addition, the effects of denervation on urethral anatomy were investigated.MethodsA leak point pressure (LPP) test was first used to demonstrate that pudendal nerve transection induced SUI. Cystometry exhibited changes in voiding function and EUS‐EMG measurements provided a quantitative evaluation of EUS activity during voiding. The morphological changes in sections through the mid‐urethra were assessed with hematoxylin and eosin (H&E) staining.ResultsA significant decrease in average LPP was detected in rats 6 weeks after bilateral pudendal nerve transection (BPNT). Abnormal urodynamic measurements including a decrease in contraction amplitude and voided volume as well as an increase in contraction duration, and residual volume all indicated inefficient voiding. In addition EUS‐EMG silent periods were reduced and the frequency of EUS‐EMG bursting during voiding was increased. Atrophy of striated muscle in the EUS was also detected in rats with pudendal nerve transection(s).ConclusionsOur results indicate that pudendal nerve transection in rats decreases urethral outlet resistance and causes striated muscle atrophy in the EUS, EUS‐EMG abnormalities and inefficient voiding. The results demonstrate that BPNT is a durable model for SUI. Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.
Rezeptor‐vermittelte Parkinson‐Therapeutika. Konkurrenz für den “Goldstandard” L‐DOPA?
Authors: Böckler Frank 
Published: April 2006

AbstractSeit der ersten Anwendung vonL‐DOPA an Parkinson‐Patienten in den 1960er Jahren hat sichL‐DOPA als “Goldstandard” für die Therapie von MP etabliert. Vor allem die im Laufe der Langzeittherapie auftretenden Dyskinesien und die verminderte Wirksamkeit limitieren die Anwendbarkeit vonL‐DOPA jedoch ganz erheblich. Im Bereich der Rezeptor‐vermittelten Parkinson‐Therapeutika eignen sich besonders einige Dopamin‐Agonisten wie z.B. Pramipexol, Ropinirol oder die Ergolinderivate als Therapeutika im Frühstadium, um den Einsatz vonL‐DOPA so lange wie möglich hinauszuzögern. Auch im fortgeschrittenen Stadium kann die Kombination von Dopaminrezeptor‐Agonisten mitL‐DOPA dabei helfen die notwendigen Dosen vonL‐DOPA zu reduzieren. Anticholinergika und NMDA‐Antagonisten sind vor allem zur Therapie von leichteren Fällen und besonderen Symptomausprägungen geeignet. Die kommenden Jahre werden zeigen, ob es auch gelingt dieL‐DOPA‐induzierten Dyskinesien direkt zu therapieren.
Retinazellen gegen Morbus Parkinson
Authors: Stark Holger 
Published: April 2006

AbstractIn einer Studie bei sechs Probanden mit fortgeschrittener idiopathischer Morbus‐Parkinson‐Erkrankung haben US‐Wissenschaftler humane retinale Pigmentepithelzellen in die Basalganglien der Patienten verpflanzt. Diese Zellen waren aus post mortalem Augengewebe von Organspendern gewonnen und kultiviert worden und waren in der Lage, L‐DOPA zu produzieren.