bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and characterization of hyperbranched cationic polyelectrolytes via aqueous self‐condensing atom transfer radical polymerization
Authors: Gao Jun , Zhai Guangqun , Song Yan , Jiang Bibiao 
Published: February 2009

AbstractThe hyperbranched cationic polyelectrolytes (PDMEAB) were directly prepared via the CuBr/ligand‐catalyzed (ligand = 2,2′‐bipyridine or pentamethyldiethylenetriamine) aqueous self‐condensing atom transfer radical polymerization (SCATRP) of a novel inimer, N,N‐dimethyl‐N‐(2‐methacryloyloxy)ethyl‐N‐(2‐bromoisobutyryloxy)ethyl ammonium bromide (DMEAB). Elemental analysis and nuclear magnetic resonance (NMR) spectroscopy confirmed the structure of DMEAB. The hyperbranched architecture and number‐average degree of polymerization (DPn) of the PDMEAB was studied by 1H‐ and 13C‐NMR. The kinetic results suggested that the DPn of the hyperbranched PDMEAB grew gradually in the initial stage and exponentially in the later stage. The differential scanning calorimetry (DSC) showed that the glass transition temperature of the hyperbranched PDMEAB was much lower than that of the linear analogue. The solution rheometry showed that the aqueous PDMEAB solutions approximately underwent a Newtonian behavior and their shear viscosity maintained almost constant upon the addition of NaCl because of the spherical conformations of the hyperbranched cationic polyelectrolytes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis of antimicrobial silver nanoparticles on silk fibers via γ‐radiation
Authors: Chang Shuquan , Kang Bin , Dai Yaodong , Chen Da 
Published: February 2009

AbstractAntimicrobial silver nanoparticles (NPs) were successfully synthesized on the surface of silk fibers via γ‐ray irradiation. The products were characterized with scanning electron microscope (SEM), energy dispersion spectrum, and X‐ray diffraction. The results revealed that the silver particles with a diameter of less than 20 nm were immobilized and well dispersed on the surface of silk fibers. The antimicrobial capability against the gram positive bacterium Staphylococcus aureus and the washing stability of the silk fibers produced with different conditions were tested and found to be excellent. The silk fibers treated with 1 mM solution and 10 kGy γ‐radiation showed 96% antimicrobial activity and still kept above 85% antibacterial activity after 10 washing cycles. Moreover, a mechanism for the formation of silver NPs on silk fibers under γ‐radiation was generally discussed. The resulting silk fibers coated with silver NPs can be useful as functional fabrics in a range of applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Pervaporation performance of polydimethylsiloxane membranes for separation of benzene/cyclohexane mixtures
Authors: Chen Jian , Li Jiding , Lin Yangzheng , Chen Cuixian 
Published: February 2009

AbstractCrosslinked polydimethylsiloxane/polyetherimide (PDMS/PEI) composite membranes were prepared, in which asymmetric microporous PEI membrane prepared with phase inversion method was acted as the microporous supporting layer in the flat‐plate composite membrane. The different function composition of the PDMS/PEI composite membranes were characterized by reflection Fourier transform infrared (FTIR) spectroscopy. The surface and section of PDMS/PEI composite membranes were investigated by scanning electron microscope (SEM). The composite membranes prepared in this work were employed in pervaporation separation of benzene/cyclohexane mixtures. Effects of feed temperature, feed composition, concentration of crosslinking agent on the separation efficiency of benzene/cyclohexane mixtures were investigated experimentally. In addition, the swelling rate and stableness of composite membrane during long time operation were studied, which should be significant for practical application. The results demonstrated that the pervaporation method could be very effective for separation of the benzene/cyclohexane mixtures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Drug diffusion in neutral and ionic hydrogels assembled from acetylated galactoglucomannan
Authors: Voepel Jens , Sjöberg John , Reif Michael , Albertsson Ann‐Christine , Hultin Ulla‐Karin , Gasslander Ulla 
Published: February 2009

AbstractIn this study, hydrogels based on acetylated galactoglucomannan (AcGGM)—a hemicellulose present in softwood—were synthesized and examined for their properties in drug‐release systems using two model substances of different molecular weight, size, and polarity (caffeine and vitasyn blue). Neutral hydrogels were produced from functionalized AcGGM using hydroxyethyl methacrylate (HEMA) coupled via carbonyldiimidazole (CDI) and a co‐monomer in a radical‐initiated polymerization. Through a second modification reaction between the HEMA‐modified AcGGM (M‐AcGGM‐methacrylated AcGGM) and maleic anhydride, a “double‐modified” AcGGM (CM‐AcGGM‐carboxylated M‐AcGGM) was successfully formed that could be cross‐linked to form ionic hydrogels by the very same polymerization method. The neutral hydrogels showed drug release kinetics that could be easily regulated by changing the relative amount of the methacrylated AcGGM and its corresponding degree of methacrylation. The drug release rate and the Fickian swelling decreased with an increase in these two aforementioned parameters. The ionic hydrogels showed quicker release kinetics and higher swelling capabilities than the corresponding nonionic gels did, especially at neutral conditions. Under acidic conditions, the release speed was lowered as expected because of protonation of carboxylic functionalities. Based on the findings we conclude that these novel hemicellulose‐containing hydrogels have future prospects in drug release formulations, e.g., in a later stage of development for application in oral drug administration technology. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Polyurethane foams from soyoil‐based polyols
Authors: Campanella A. , Bonnaillie L. M. , Wool R. P. 
Published: February 2009

AbstractThe focus of this work was to synthesize bio‐based polyurethane (PU) foams from soybean oil (SO). Different polyols from SO were produced as follows: soybean oil monoglyceride (SOMG), hydroxylated soybean oil (HSO), and soybean oil methanol polyol (SOMP). The SOMG was a mixture of 90.1% of monoglyceride, 1.3% of diglyceride, and 8.6% of glycerol. The effect of various variables (polyol reactivity, water content curing temperature, type of catalyst, isocyanate, and surfactant) on the foam structure and properties were analyzed. SOMG had the highest reactivity because it was the only polyol‐containing primary hydroxyl (OH) groups in addition to a secondary OH group. PU foams made with SOMG and synthetic polyol contained small uniform cells, whereas the other SO polyols produced foams with a mixture of larger and less uniform cells. The type of isocyanate also had an influence on the morphology, especially on the type of cells produced. The foam structure was found to be affected by the water and catalyst content, which controlled the foam density and the cure rate of the PU polymer. We observed that the glass transition (Tg) increased with the OH value and the type of diisocyanate. Also, we found that the degree of solvent swelling (DS) decreased as Tg increased with crosslink density. These results are consistent with the Twinkling Fractal Theory of Tg. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Characteristic Morphology and Distribution of Bone Marrow Derived Cells in the Cornea
Authors: Takayama Tetsuya , Kondo Teruyoshi , Kobayashi Masatoshi , Ohta Keisuke , Ishibashi Yoshihiro , Kanemaru Takaaki , Shimazu Hideki , Ishikawa Fumihiko , Nakamura Takahiro , Kinoshita Shigeru , Nakamura Kei‐Ichiro 
Published: February 2009

AbstractEnhanced green fluorescence protein (eGFP)‐labeled bone marrow (BM) cells were transplanted into syngeneic C57BL/6 (wild‐type) mice to investigate the distribution pattern, immunohistochemical characteristics, three‐dimensional structure, and ultrastructure of the BM‐derived cells in the mouse cornea using a fluorescence microscope, a confocal laser scanning microscope, and a transmission electron microscope. This study provided direct evidence that two morphologically distinct types of BM‐derived cells were distributed in the mouse cornea. The majority of the GFP(+) cells showed a flattened polygonal form with obtuse angles and these cells were distributed in the corneal stroma. The other type was the GFP(+) cells demonstrating slim cell bodies with long and extremely thin dendrites and which were distributed in the corneal epithelium. The immunohistochemical characteristics and ultrastructure of BM‐derived cells suggest that most of these cells have a macrophage lineage, whereas some cells in the corneal stroma do not. Interestingly, the direct intimate contact between GFP‐labeled BM derived cells and non‐GFP‐labeled resident cells within the corneal stroma were also clearly visualized at the fine structural level. These data provide new and more detailed insight into the nature of BM‐derived cells in the cornea. Anat Rec, 2009. © 2009 Wiley‐Liss, Inc.
Libcitations: A measure for comparative assessment of book publications in the humanities and social sciences
Authors: White Howard D. , Boell Sebastian K. , Yu Hairong , Davis Mari , Wilson Concepción S. , Cole Fletcher T.H. 
Published: February 2009

AbstractBibliometric measures for evaluating research units in the book‐oriented humanities and social sciences are underdeveloped relative to those available for journal‐oriented science and technology. We therefore present a new measure designed for book‐oriented fields: the “libcitation count.” This is a count of the libraries holding a given book, as reported in a national or international union catalog. As librarians decide what to acquire for the audiences they serve, they jointly constitute an instrument for gauging the cultural impact of books. Their decisions are informed by knowledge not only of audiences but also of the book world (e.g., the reputations of authors and the prestige of publishers). From libcitation counts, measures can be derived for comparing research units. Here, we imagine a match‐up between the departments of history, philosophy, and political science at the University of New South Wales and the University of Sydney in Australia. We chose the 12 books from each department that had the highest libcitation counts in the Libraries Australia union catalog during 2000 to 2006. We present each book's raw libcitation count, its rank within its Library of Congress (LC) class, and its LC‐class normalized libcitation score. The latter is patterned on the item‐oriented field normalized citation score used in evaluative bibliometrics. Summary statistics based on these measures allow the departments to be compared for cultural impact. Our work has implications for programs such as Excellence in Research for Australia and the Research Assessment Exercise in the United Kingdom. It also has implications for data mining in OCLC's WorldCat.
Light Harvesting and Efficient Energy Transfer in Dendritic Systems: New Strategy for Functionalized Near‐Infrared BF2‐Azadipyrromethenes
Authors: Yuan Mingjian , Yin Xiaodong , Zheng Haiyan , Ouyang Canbin , Zuo Zicheng , Liu Huibiao , Li Yuliang 
Published: February 2009

AbstractBright funnels: A series of dendritic systems, which are capable of funneling energy from the periphery to the core, have been synthesized. The photophysical properties of dendrimers have been determined. Selective excitation of the donor leads to an efficient energy transfer (>90 %) to the acceptor. The approach provides a facile synthesis for the modification of near‐infrared BF2‐Azadipyrromethenes.magnified imageA series of dendritic systems, which are capable of funneling energy from the periphery to the core, have been synthesized. The photophysical properties of the dendrimers, generations 0–2, have been determined. The light‐harvesting ability of these compounds increases with increasing generation arising from the increase in molar extinction coefficient. Selective excitation of the donor leads to an efficient energy transfer (>90 %) to the acceptor. The approach provides a facile synthesis for modification of near‐infrared BF2‐Azadipyrromethene.
Unusual Side‐Chain Effects on Charge‐Carrier Lifetime in Discotic Liquid Crystals
Authors: Motoyanagi Jin , Yamamoto Yohei , Saeki Akinori , Alam Md. Akhtarul , Kimoto Atsushi , Kosaka Atsuko , Fukushima Takanori , Seki Shu , Tagawa Seiichi , Aida Takuzo 
Published: February 2009

AbstractLong live the carrier! Hexa‐peri‐hexabenzocoronene derivatives, carrying paraffinic side chains terminated with ester–ether groups, form hexagonal columnar assemblies over a wide temperature range including room temperature. Within this temperature range, the lifetimes of charge carriers generated by laser flash photolysis are observed to be extremely long (14–40 ms).magnified imageWhen hexa‐peri‐hexabenzocoronene (HBC) carries paraffinic side chains with ester–ether termini (1 a–1 c), a hexagonal columnar liquid‐crystalline (LC) mesophase forms, which is characterized by a very wide temperature range (ca. 0–300 °C). The LC materials from these HBC derivatives show characteristic electronic properties with an extremely long photocarrier lifetime. For example, by means of a flash‐photolysis time‐resolved microwave conductivity technique, the photocarrier lifetime, observed for liquid‐crystalline 1 a, is as long as 14 ms, which is four‐orders of magnitude longer than that of fully paraffinic HBC 4 (0.0011 ms). The maximum transient photoconductivities of liquid‐crystalline 1 a–1 c are comparable to one another and also to those of HBCs without ester–ether terminals. Liquid‐crystalline 1 a exhibits an obvious photocurrent generation in response to light illumination.
Growth inhibition of Staphylococcus aureus induced by low‐frequency electric and electromagnetic fields
Authors: Obermeier Andreas , Matl Florian Dominik , Friess Wolfgang , Stemberger Axel 
Published: February 2009

AbstractMagnetic field therapy is an established technique in the treatment of pseudarthrosis. In cases of osteomylitis, palliation is also observed. This study focuses on the impact of different electric and electromagnetic fields on the growth of Staphylococcus aureus by in vitro technologies. Cultures of Staphylococcus aureus in fluid and gel‐like medium were exposed to a low‐frequency electromagnetic field, an electromagnetic field combined with an additional electric field, a sinusoidal electric field and a static electric field. In gel‐like medium no significant difference between colony‐forming units of exposed samples and non‐exposed references was detected. In contrast, Staphylococcus aureus concentrations in fluid medium could clearly be reduced under the influence of the four different applied fields within 24 h of experiment. The strongest effects were observed for the direct current electric field which could decrease CFU/ml of 37%, and the low‐frequency electromagnetic field with additional induced electric alternating field with a decrease of Staphylococci concentration by 36%. The effects of the electromagnetic treatment on Staphylococci within fluid medium are significantly higher than in gel‐like medium. The application of low‐frequency electromagnetic fields corroborates clinical situations of bone infections during magnetic field therapy. Bioelectromagnetics 30:270–279, 2009. © 2009 Wiley‐Liss, Inc.
Piezoelectric inkjet printing of a cross‐hatch immunoassay on a disposable nylon membrane
Authors: Stewart Thomas N. , Pierson Bonnie E. , Aggarwal Ravi , Narayan Roger J. 
Published: February 2009

AbstractThe development of a cost‐effective method for manufacturing immunoassays is a key step towards their commercial use. In this study, a piezoelectric inkjet printer and a nylon membrane were used to fabricate a disposable immunoassay. Using a piezoelectric inkjet printer, a cross‐hatch pattern of goat anti‐mouse antibody (GαM) and rabbit anti‐horseradish peroxidase (RαHRP) antibody were deposited on the nylon membrane. These patterns were subsequently treated with a solution containing rabbit anti‐goat antibody labeled with horseradish peroxidase (RαG‐HRP). The effectiveness of the immobilization process was examined using tetramethylbenzidine (TMB), which oxidizes in the presence of HRP to form a visible precipitate. Optical evaluation of the TMB precipitate was used to assess the precision of the features in the inkjet‐printed pattern as well as antibody functionality following inkjet printing. Uniform patterns that contained functional antibodies were fabricated using the piezoelectric inkjet printer. These results suggest that piezoelectric inkjet printing may be used to fabricate low‐cost disposable immunoassays for biotechnology and healthcare applications.
Calmodulin effects on steroids‐regulated plasma membrane calcium pump activity
Authors: Zylinska Ludmila , Kowalska Iwona , Ferenc Bozena 
Published: February 2009

AbstractIt is now generally accepted that non‐genomic steroids action precedes their genomic effects by modulation of intracellular signaling pathways within seconds after application. Ca2+is a very potent and ubiquitous ion in all cells, and its concentration is precisely regulated. The most sensitive on Ca2+increase is ATP‐consuming plasma membrane calcium pump (PMCA). The enzyme is coded by four genes, but isoforms diversity was detected in excitable and non‐excitable cells. It is the only ion pump stimulated directly by calmodulin (CaM). We examined the role of PMCA isoforms composition and CaM effect in regulation of Ca2+uptake by estradiol, dehydroepiandrosterone (DHEA), pregnenolone (PREG), and their sulfates in a concentration range from 10−9to 10−6 M, using the membranes from rat cortical synaptosomes, differentiated PC12 cells, and human erythrocytes. In excitable membranes with full set of PMCAs steroids apparently increased Ca2+uptake, although to a variable extent. In most of the cases, CaM decreased transport by 30–40% below controls. Erythrocyte PMCA was regulated by the steroids somewhat differently than excitable cells. CaM strongly increased the potency for Ca2+extrusion in membranes incubated with 17‐β‐estradiol and PREG. Our results indicated that steroids may sufficiently control cytoplasmic calcium concentration within physiological and therapeutic range. The response depended on the cell type, PMCA isoforms expression profile, CaM presence, and the steroids structure. Copyright © 2009 John Wiley & Sons, Ltd.
On‐Chip Fragment‐Based Approach for Discovery of High‐Affinity Bivalent Inhibitors
Authors: Miyazaki Isao , Simizu Siro , Ishida Keisuke , Osada Hiroyuki 
Published: February 2009

AbstractCovalent bonds not required: We describe a novel approach in which the concepts of fragment‐based ligand discovery are combined with chemical array techniques to yield bivalent inhibitors. A pair of fragments is mixed and covalently attached to a glass slide by photolinking immobilization. The method does not require the compounds to have specific functional groups, and tedious steps for protein purification are avoided. Thus, the on‐chip fragment‐based approach is relatively simple and efficient for obtaining high‐affinity ligands.magnified image
Synthesis of a Fluorogenic Analogue of Sphingosine‐1‐Phosphate and Its Use to Determine Sphingosine‐1‐Phosphate Lyase Activity
Authors: Bedia Carmen , Camacho Luz , Casas Josefina , Abad José Luis , Delgado Antonio , Van Veldhoven Paul P. , Fabriàs Gemma 
Published: February 2009

AbstractIlluminating an ER enzyme: We report on the design and synthesis of a fluorogenic chemical sensor (1) to measure sphingosine‐1‐phosphate lyase activity in high‐throughput screening formats, as well as its validation using lyase knockout (Sgpl1−/−) cells.magnified image
Regulation of sperm flagellar motility activation and chemotaxis caused by egg‐derived substance(s) in sea cucumber
Authors: Morita Masaya , Kitamura Makoto , Nakajima Ayako , Sri Susilo Endang , Takemura Akihiro , Okuno Makoto 
Published: February 2009

AbstractThe sea cucumber Holothuria atra is a broadcast spawner. Among broadcast spawners, fertilization occurs by means of an egg‐derived substance(s) that induces sperm flagellar motility activation and chemotaxis. Holothuria atra sperm were quiescent in seawater, but exhibited flagellar motility activation near eggs with chorion (intact eggs). In addition, they moved in a helical motion toward intact eggs as well as a capillary filled with the water layer of the egg extracts, suggesting that an egg‐derived compound(s) causes motility activation and chemotaxis. Furthermore, demembranated sperm flagella were reactivated in high pH (>7.8) solution without cAMP, and a phosphorylation assay using (γ‐32P)ATP showed that axonemal protein phosphorylation and dephosphorylation also occurred in a pH‐dependent manner. These results suggest that the activation of sperm motility in holothurians is controlled by pH‐sensitive changes in axonemal protein phosphorylation. Ca2+ concentration affected the swimming trajectory of demembranated sperm, indicating that Ca2+‐binding proteins present at the flagella may be associated with regulation of flagellar waveform. Moreover, the phosphorylation states of several axonemal proteins were Ca2+‐sensitive, indicating that Ca2+ impacts both kinase and phosphatase activities. In addition, in vivo sperm protein phosphorylation occurred after treatment with a water‐soluble egg extract. Our results suggest that one or more egg‐derived compounds activate motility and subsequent chemotactic behavior via Ca2+‐sensitive flagellar protein phosphorylation. Cell Motil. Cytoskeleton 2009. © 2009 Wiley‐Liss, Inc.
Gliotoxin reverses age‐dependent nuclear morphology phenotypes, ameliorates motility, but fails to affect lifespan of adult Caenorhabditis elegans
Authors: Bar Daniel Z. , Neufeld Ester , Feinstein Naomi , Gruenbaum Yosef 
Published: February 2009

AbstractSpecific mutations in human LMNA or loss of ZMPSTE26 activity cause abnormal processing of lamin A and early aging diseases, including Hutchinson Gilford progeria syndrome (HGPS). HGPS fibroblasts in culture undergo age‐dependent progressive changes in nuclear architecture. Treating these cells with farnesyl transferase inhibitors (FTIs) reverse these nuclear phenotypes and also extend lifespan of mice HGPS models. Dermal cells derived from healthy old humans also accumulate the abnormally processed lamin A. However, the effect of FTIs on normal aging cells was not tested. Aging adult C. elegans cells show changes in nuclear architecture similar to HGPS fibroblasts and down regulating lamin expression in adult C. elegans reduces their lifespan. Here, we show that nuclei of adult C. elegans, in which lamin is down‐regulated, have similar phenotypes to normal aging nuclei, but at an earlier age. We further show that treating adult C. elegans with the FTI gliotoxin reverses nuclear phenotypes and improves motility of aging worms. However, the average lifespan of the gliotoxin‐treated animals was similar to that of untreated animals. These results suggest that lamins are involved in the process of normal aging in C. elegans. Cell Motil. Cytoskeleton 2009. © 2009 Wiley‐Liss, Inc.
Design, Synthesis, and Biological Evaluation of Levoglucosenone‐Derived Ras Activation Inhibitors
Authors: Müller Christian , Gomez‐Zurita Frau Maria Antonia , Ballinari Dario , Colombo Sonia , Bitto Alessandro , Martegani Enzo , Airoldi Cristina , van Neuren Anske Stephanie , Stein Matthias , Weiser Jörg , Battistini Carlo , Peri Francesco 
Published: February 2009

AbstractA panel of new potential Ras ligands was generated by decorating a tricyclic levoglucosenone‐derived scaffold with aromatic moieties. Some members of the panel show in vitro inhibitory activity toward the nucleotide exchange process on Ras and are toxic to some human cancer cell lines.magnified image