bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of chitosan/PEG/gelatin composites for tissue engineering
Authors: Hong Hua , Liu Changsheng , Wu Wenjing 
Published: June 2009

AbstractChitosan scaffolds have gained much attention in tissue engineering. However, brittleness and low biodegradability limit scaffolds application, especially in use as guided tissue regeneration membranes (GTRm) in surgical operations. The first objective of this work is to improve the brittleness of the chitosan membrane, which is not desired for use via adding polyethylene glycol (PEG) to chitosan, and the second objective is to accelerate the degradation rate by blending gelatin with the binary chitosan‐PEG mixture. The addition of PEG softened the blend membrane in vision and in touch. The tensile compliant increased from 7.87 × 10−3 (MPa−1) for chitosan membrane to 3.63 × 10−1 (MPa−1) for chitosan‐PEG‐gelatin (CPG) membrane. Degradation results in vitro indicated that CPG membrane degraded faster and weight loss increased more significantly than chitosan membrane and the lowest tensile strength of CPG membrane could meet the requirement of the application. CPG membrane showed significant improvement in degradation and flexibility in comparison with the chitosan membrane. Cell adhesion, viability, and proliferation onto the external surface of CPG membrane with C2C12 cell had been evaluated in vitro and quantified by a methyl thiazolyl tetrazolium (MTT) reduction assay. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The influence of loose and semianchored siloxane polymer chains on the tack of crosslinked silicone rubber
Authors: Mikrut Marek , Noordermeer Jacques W.M. , Verbeek Guy 
Published: June 2009

AbstractThe influence of addition of nonreactive silicone oil or semianchored silicone polymer on crosslinked poly(dimethylsiloxane) (PDMS) rubber–rubber adhesion was studied. The additives can be considered either a tackifier, or connector molecules, able to cross the interface and entangle. In both cases, it influences the tack of the elastomers. An additional variable is the molecular weight of the additive, which affects the reptation of the polymer chains. Polymer–polymer demixing, which is the result of thermodynamic incompatibility of mixed polymers is another factor that influences tack. It causes the free chains to appear at the surface forming a layer of oil, which actually destroys the tack of the PDMS samples. The resulting tack phenomena as a function of oil, respectively semianchored silicone polymer chains, are very much dependent on the transient nature of the polymer reptation: in many cases the polymers need very long time periods to obtain equilibrium in interphase crossing, or oil sweats out of the crosslinked polymers, forming a liquid layer between the two phases resulting in a low tack value, due to hydrodynamic wetting alone. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Improving the performance of urea‐formaldehyde wood adhesive system using dendritic poly(amidoamine)s and their corresponding half generations
Authors: Essawy Hisham A. , Moustafa Abd‐Allah B. , Elsayed Nadia H. 
Published: June 2009

AbstractFull as well as half generations of dendritic poly(amido amine)s (PAMAMs) were introduced onto urea‐formaldehyde (UF) wood adhesive system as modifiers to increase its stability and enhance the performance of the bonded wood joints with it. The effect of the modifiers on the physical properties and mechanical performance was discussed on the light of gel times, curing exotherms using differential scanning calorimetry (DSC), infra‐red (IR), and shear strength measurements. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Conductive network formation and electrical properties of poly(vinylidene fluoride)/multiwalled carbon nanotube composites: Percolation and dynamic percolation
Authors: Zhang Cheng , Zhu Jun , Ouyang Mi , Ma Chunan , Sumita Masao 
Published: June 2009

AbstractConductive network formation and its dynamic process for multiwalled carbon nanotubes (MWNTs) and carboxyl‐tethered MWNT (MWNT‐COOH) filled poly(vinylidene fluoride)(PVDF) systems were investigated. Based on real‐time tracing the variation of electrical resistivity of systems with isothermal treatment time, the conductive network formation was evaluated. It was found that the conductive network formation was temperature and time dependent. The percolation time, characterized at a certain annealing time where the electrical resistivity started to decrease drastically, decreased with the increase of the filler concentration or the annealing temperature. However, the values of the percolation time and the activation energy of conductive network formation for the PVDF/MWNT‐COOH system were higher than those of the PVDF/MWNT system, indicating that the interaction between MWNTs and PVDF molecules played an important role in the conductive network formation of the composites. Furthermore, a modified thermodynamic percolation model was proposed to predict the percolation time of PVDF/MWNT composites. It was found that the calculated results fit the experimental data very well. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Light and Scanning Electron Microscopic Study on the Tongue and Lingual Papillae of the Common Hippopotamus, Hippopotamus amphibius amphibius
Authors: Yoshimura Ken , Hama Natsuki , Shindo Junji , Kobayashi Kan , Kageyama Ikuo 
Published: June 2009

AbstractWe observed the three‐dimensional structures of the external surface and connective tissue cores CTCs, after exfoliation of the epithelium of the lingual papillae (filiform, fungiform, and foliate papillae) of the common hippopotamus (Hippopotamus amphibius amphibius) using scanning electron microscopy and conventional light microscopy. Following unique features were found; typical vallate papillae with a circumferential furrow were not observable. Instead, numerous large fungiform papillae were rather densely distributed on the posterior of the lingual prominence. Taste buds were observable only on the dorsal epithelium. Serous lingual gland was not seen in the lamina propria; however, mucous‐rich mixed lingual glands were found and in a few of orifices were seen on the large fungiform tops. Lingual prominence was diminished their width. Rather long and slender conical papillae were distributed on the lingual prominence and were similar to nonruminant herbivore, that is donkey. Beside this narrow lingual prominence, lateral slopes were situated with numerous short spine‐like protrusions. After removal of the epithelium, CTCs of lateral slopes exhibited attenuated flower bud structures. Large‐conical papillae were situated on the root of the tongue. These large conical papillae were not seen among ruminants and seen on the lingual root of omnivores and carnivores. It implies that lingual structure of common hippopotamus possessed mixed characteristics between Perissodactyls, Ruminantia, and nonherbivores such as Suiformes because of their unique evolutionally taxonomic position. Moreover, adaptation for soft grass diet and associating easier mastication may be also affecting these mixed morphological features of the tongue. Anat Rec, 292:921–934, 2009. © 2009 Wiley‐Liss, Inc.
The Antiproliferation Effect of Berbamine on K562 Resistant Cells by Inhibiting NF‐κB Pathway
Authors: Wei Yan‐Lin , Liang Yun , Xu Lei , Zhao Xiao‐Ying 
Published: June 2009

AbstractImatinib mesylate is effective against Ph chromosome‐positive leukemia; however, resistance has been reported. High expression of bcr‐abl in mRNA and protein levels, and other alterations were found in patients who experienced imatinib treatment failures and thus it is important to design alternative treatment strategies. The aim of this study was to evaluate the in vitro effect of berbamine, on imatinib‐resistant chronic myelogenous leukemia (CML) K562 (K562‐r) cells, and explore the mechanisms. The growth of K562‐r cells was examined using the 3‐(4,5‐dimethylthiazol‐2yl)‐2,5‐diphenyl‐tetrazolium bromide (MTT) assay. Morphological analysis and DNA agarose electrophoresis were used to detect apoptosis in K562‐r cells, and the extent of the cells in the sub‐G1 cell cycle phase was measured using flow cytometry. The expression levels of BCR‐ABL, phospho‐BCR‐ABL, and nuclear factor κB (NF‐κB), IκBα, phospho‐IκBα, IκB kinases α(IKKα), and Survivin were determined by Western blot. bcr‐abl mRNA expression was determined by RT‐PCR. MTT assays indicated that berbamine significantly inhibited the proliferation of K562‐r cells. Cells with characteristics of apoptosis were confirmed by morphology examination and DNA agarose electrophoresis and percentage of apoptosis were increased after treatment with berbamine. The results also showed that berbamine was able to down‐regulate BCR‐ABL and phospho‐BCR‐ABL proteins by affecting bcr‐abl mRNA expression and decrease expression of nuclear NF‐κB, phospho‐IκBα, IKKα, and Survivin. Collectively, berbamine could inhibit the proliferation of K562‐r cells and induce apoptosis. The mechanisms may be related at least in part, to inhibit BCR‐ABL and its downstream NF‐κB signaling. Berbamine may provide an alternative candidate for the treatment of patients with CML resistant to imatinib therapy. Anat Rec, 292:945–950, 2009. © 2009 Wiley‐Liss, Inc.
Plasticity of Interstitial Cells of Cajal: A Study in the Small Intestine of Adult Guinea Pigs
Authors: Mei Feng , Han Juan , Huang Yue , Jiang Zhong‐Yong , Xiong Cheng‐Jie , Zhou De‐Shan 
Published: June 2009

AbstractAlthough it is well known that the reduction of interstitial cells of Cajal (ICCs) is associated with several gastrointestinal motility disorders in clinic, it is unknown whether the mature ICCs still have an active plasticity in adult mammals. This study focused on the issues of the reduction of ICCs during Imatinib administration and the recovery of ICCs following drug withdrawal in the small intestine of adult guinea pigs. ICCs were revealed by immunofluorescence on whole mount preparations with anti‐Kit, α‐smooth muscle actin, (α‐SMA), and 5‐bromo‐2′‐deoxyuridine (BrdU) antibodies. Moreover, the occurrence of apoptosis was also assayed. Imatinib treatment led to a gradual reduction of ICCs in number around the myenteric plexus and deep muscular plexus, which was dependent on the time but no apoptosis of ICCs was detected with the TUNEL method. During Imatinib treatment, some ICC‐like cells were double labeled for Kit and α‐SMA and a few ICC‐like cells were only stained with α‐SMA. When Imatinib was discontinued, the number of ICCs recovered to normal within 32 days. During this time, some proliferating ICCs were demonstrated by double labeling with Kit and BrdU antibodies. Our results indicated that Kit signaling was essential for the maintenance of survival and proliferation of the mature ICCs in the small intestine of adult guinea pigs. Moreover, ICCs might transdifferentiate to a type of α‐SMA+ cells, perhaps a phenotype of smooth muscle cells, when there is a loss‐of‐function of Kit. Anat Rec, 292:985–993, 2009. © 2009 Wiley‐Liss, Inc.
A cluster analysis of scholar and journal bibliometric indicators
Authors: Franceschet Massimo 
Published: June 2009

AbstractWe investigate different approaches based on correlation analysis to reduce the complexity of a space of quantitative indicators for the assessment of research performance. The proposed methods group bibliometric indicators into clusters of highly intercorrelated indicators. Each cluster is then associated with a representative indicator. The set of all representatives corresponds to a base of orthogonal metrics capturing independent aspects of research performance and can be exploited to design a composite performance indicator. We apply the devised methodology to isolate orthogonal performance metrics for scholars and journals in the field of computer science and to design a global performance indicator. The methodology is general and can be exploited to design composite indicators that are based on a set of possibly overlapping criteria.
Visual health subject directory analysis based on users' traversal activities
Authors: Zhang Jin , An Lu , Tang Tao , Hong Yi 
Published: June 2009

AbstractConcerns about health issues cover a wide spectrum. Consumer health information, which has become more available on the Internet, plays an extremely important role in addressing these concerns. A subject directory as an information organization and browsing mechanism is widely used in consumer health‐related Websites. In this study we employed the information visualization technique Self‐Organizing Map (SOM) in combination with a new U‐matrix algorithm to analyze health subject clusters through a Web transaction log. An experimental study was conducted to test the proposed methods. The findings show that the clusters identified from the same cells based on path‐length‐1 outperformed both the clusters from the adjacent cells based on path‐length‐1 and the clusters from the same cells based on path‐length‐2 in the visual SOM display. The U‐matrix method successfully distinguished the irrelevant subjects situated in the adjacent cells with different colors in the SOM display. The findings of this study lead to a better understanding of the health‐related subject relationship from the users' traversal perspective.
Surface model of the gastrointestinal tract constructed from the Visible Korean
Authors: Shin Dong Sun , Park Jin Seo , Lee Seung‐Bock , Lee Sang‐Ho , Chung Jinoh , Chung Min Suk 
Published: June 2009

AbstractMost currently available three‐dimensional surface models of human anatomic structures have been artistically created to reflect the anatomy being portrayed. We have recently undertaken, as part of our Visible Korean studies, to build objective surface models based on cross‐sectional images of actual human anatomy. Objective of the present study was to elaborate surface models of the GI tract and neighboring structures that are helpful to medical simulation. The GI tract from stomach to anal canal was outlined and reconstructed from sectioned images of the Visible Korean (acomputer database containing the digitized transverse sectional images of a 33‐year‐old Korean man). The outlining procedure was supported by computational filtering and interpolation using commercially available software. The GI tract was divided into several parts, and each of these parts was surface reconstructed and then united with neighboring parts to produce a surface model of the complete GI tract. Surface models of about 100 neighboring structures were also prepared. The surface models produced will hopefully facilitate the development of interactive simulations for a variety of virtual abdominal surgical procedures or other educational programs. In addition, it is hoped that the improved outlining and surface reconstruction techniques described will encourage other researchers to construct similar surface models based on images obtained from different subjects. Clin. Anat. 22:601–609, 2009. © 2009 Wiley‐Liss, Inc.
Glycoprotein isolated from Dioscorea batatas Decne modulates expressions of IL‐4 and IL‐10 in primary‐cultured mouse lymphocytes
Authors: Oh Phil‐Sun , Lim Kye‐Taek 
Published: June 2009

AbstractIn the present study, we investigated the anti‐allergic activity of a glycoprotein isolated from Dioscorea batatas Decne (DBD glycoprotein, 30 kDa) on ovalbumin (OVA, 100 µg ml−1)‐induced T helper (Th) type‐2 response in primary cultured mouse lymphocytes. Our results revealed that the DBD glycoprotein (200 µg ml−1) significantly attenuated the expressions of interleukin (IL)‐4 and IL‐10, whereas enhanced the expression of interferon (IFN)‐γ in OVA (100 µg ml−1)‐treated primary cultured lymphocytes. We also found that the DBD glycoprotein has inhibitory effects on phosphorylations of signal transducer and activator of transcription (STAT)‐6, p44/42 mitogen‐activated protein kinase (MAPK) and p38 MAPK in primary cultured lymphocytes. Interestingly, the DBD glycoprotein suppressed the transcriptional activation of GATA‐binding protein 3 (GATA‐3), whereas it enhanced the activity of t‐box expressed in T cells (T‐bet) in OVA‐stimulated lymphocytes. The results from these experiments indicated that the DBD glycoprotein inhibits expressions of IL‐4 and IL‐10 through modulation of GATA‐3, STAT‐6, p44/42 MAPK and p38 MAPK in mouse lymphocytes. Therefore, we speculated that the DBD glycoprotein might be one component for preparation of nutraceutical health supplements for prevention of Th2 cell response‐related immune disorder. Copyright © 2009 John Wiley & Sons, Ltd.
Fast chiral separation of drugs using columns packed with sub‐2 μm particles and ultra‐high pressure
Authors: Guillarme Davy , Bonvin Gregoire , Badoud Flavia , Schappler Julie , Rudaz Serge , Veuthey Jean‐Luc 
Published: June 2009

AbstractThe use of columns packed with sub‐2 μm particles in liquid chromatography with very high pressure conditions (known as UHPLC) was investigated for the fast enantioseparation of drugs. Two different procedures were evaluated and compared using amphetamine derivatives and β‐blockers as model compounds. In one case, cyclodextrins (CD) were directly added to the mobile phase and chiral separations were carried out in less than 5 min. However, this strategy suffered from several drawbacks linked to column lifetime and low chromatographic efficiencies. In the other case, the analysis of enantiomers was carried out after a derivatization procedure using two different reagents, 2,3,4‐tri‐O‐acetyl‐α‐D‐arabinopyranosyl isothiocyanate (AITC) and N‐α‐(2,4‐dinitro‐5‐fluorophenyl)‐L‐alaninamide (Marfey's reagent). Separation of several amphetamine derivatives contained within the same sample was achieved in 2–5 min with high efficiency and selectivity. The proposed approach was also successfully applied to the enantiomeric purity determination of (+)‐(S)‐amphetamine and (+)‐(S)‐methamphetamine. Similar results were obtained with β‐blockers, and the separation of 10 enantiomers was carried out in less than 3 min, whereas the individual separation of several β‐blocker enantiomers was performed in 1 min or less. Chirality, 2010. © 2009 Wiley‐Liss, Inc.
Carboxymethylated cyclodextrins and their complexes with Pr(III) and Yb(III) as water‐soluble chiral NMR solvating agents for cationic compounds
Authors: Provencher Katelyn A. , Weber Madeline A. , Randall Lauren A. , Cunningham Patrick R. , Dignam Catherine F. , Wenzel Thomas J. 
Published: June 2009

AbstractCyclodextrins that are indiscriminately carboxymethylated at the 2‐, 3‐, and 6‐positions are used as chiral NMR solvating agents for cationic substrates with phenyl, naphthyl, pyridyl, indoline, and indole rings. Enantiodifferentiation with the α‐, β‐, and γ‐cyclodextrin derivatives is compared. The carboxymethylated derivatives are almost always more effective as chiral NMR solvating agents for cationic substrates than native cyclodextrins. The most effective carboxymethylated cyclodextrin varies for different substrates, and at times even different resonances of the substrate. Addition of paramagnetic praseodymium(III) or ytterbium(III) to mixtures of the carboxymethylated cyclodextrin and substrate often causes enhancements in enantiomeric discrimination and facilitates measurements of enantiomeric purity. The lanthanide ion bonds to the carboxymethyl groups and causes perturbations in the chemical shifts in the NMR spectra of substrate molecules in the cyclodextrin cavity. Chirality, 2010. © 2009 Wiley‐Liss, Inc.
Actin‐dependent dynamics of keratin filament precursors
Authors: Kölsch Anne , Windoffer Reinhard , Leube Rudolf E. 
Published: June 2009

AbstractActin filament and microtubule growth characteristics are defined by their different plus and minus ends. In contrast, intermediate filaments lack this type of polarity. Yet, intermediate filament network growth occurs by selective addition of newly formed and polymerizing keratin particles at peripheral network domains thereby allowing polarized network reorganization. To examine this process at high resolution in living cells, mammary epithelium‐derived, immortalized EpH4‐cells were infected with retroviral cDNA constructs coding for human keratin 18‐fluorescent protein hybrids. Several stable cell lines were established presenting characteristic fluorescent keratin filament (KF) networks. These cells contain particularly large and abundant lamellipodia in which nascent keratin particle dynamics are easily detected by time‐lapse fluorescence microscopy. These keratin particles originate close to the plasma membrane, translocate continuously toward the cell center, and integrate end‐on into the peripheral KF network. We show that this inward‐directed transport relies on intact actin filaments. After treatment with the actin filament‐disrupting drug cytochalasin newly polymerizing keratin assemblies still appear in the peripheral cytoplasm but remain stationary. On the other hand, nocodazole‐mediated disruption of microtubules does not affect the centripetal KF precursor transport. From these and other observations a model is deduced which postulates that focal adhesion‐dependent keratin polymerization occurs in forming lamellipodia and that transport of newly formed keratin particles is mediated by actin filaments until network integration. This mechanism allows extension of the KF network toward the leading edge in migrating cells and may be of relevance for tissue development and regeneration. Cell Motil. Cytoskeleton 66: 976–985, 2009. © 2009 Wiley‐Liss, Inc.
Calcium‐dependent flagellar motility activation in Chlamydomonas reinhardtii in response to mechanical agitation
Authors: Wakabayashi Ken‐ichi , Ide Takahiro , Kamiya Ritsu 
Published: June 2009

AbstractFlagellar beating in Chlamydomonas was found to be activated by mechanical stimulation. Immediately after a wild‐type cell suspension was vortexed, the average swimming velocity of cells increased from 130 μm/second to 150 μm/second, due to an elevation of flagellar beat frequency from ∼60 Hz to ∼70 Hz without detectable change in the flagellar waveforms. This response required outer arm dynein. Treatment with EGTA, Ca2+‐channel blockers, or mechanosensitive‐channel blockers inhibited it. In demembranated and reactivated cell models, a modest increase in Ca2+ concentration elevated the axonemal beat frequency. These data indicate that the mechanical agitation increases beat frequency because it causes Ca2+ influx into flagella, which then activates outer arm dynein. Cell Motil. Cytoskeleton 2009. © 2009 Wiley‐Liss, Inc.
Calcium oxalate crystallization in the presence of amino acids, proteins and carboxylic acids
Authors: Sayan P. , Sargut S. Titiz , Kıran B. 
Published: June 2009

AbstractReactive crystallization of calcium oxalate was investigated in the presence of amino acids, proteins and carboxylic acids at different pH and temperatures. Average particle size, filtration rates of calcium oxalate crystals obtained in the absence and presence of additives were determined. The influence of pH, temperatures and additives on crystal morphology of calcium oxalate were also investigated and discussed by SEM analysis. TG‐DTA, FT/IR and XRD analysis were carried out for all investigated conditions. Average particle size of calcium oxalate was affected significantly by the additive type and concentration. Variation of crystal morphology depending on type and concentration of the additives affected the filtration characteristics. Majority of calcium oxalate crystals occurred in the form of calcium oxalate monohydrate except those in the presence of tartaric acid. TG‐DTA, FT/IR and XRD analysis proved that calcium oxalate monohydrate and calcium oxalate dihydrate mixtures are formed in the presence of tartaric acid. The effect of all additives on scale formation was also investigated. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)