bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of quantum dots using capillary zone electrophoresis
Authors: Pereira Mark , Lai Edward P. C. , Hollebone Bryan 
Published: July 2007

AbstractCommercially available quantum dots (QDs) were characterized using CE. The CE instruments were laboratory‐built, each being capable of both electrokinetic and hydrodynamic injection. Modes of detection include UV absorption and LIF. The CE‐LIF system was further modified to handle microliter sample volumes during injection. Sodium phosphate (5–25 mM, pH 7.5–11) was found to be a good buffer electrolyte. Sodium mercaptoproprionate CdTe/CdS (ADS620) QDs and carboxylic acid CdSe/ZnS (T2‐Evitag) QDs yielded high separation efficiencies of N = 1.5×106 plates at tM = 10 min and N = 1.0×105 plates at tM = 3.8 min, respectively. Apparently the EDC/sulfo‐NHS bioconjugation chemistry worked well with the neutral T2‐Evitag QDs, but not so well with the negatively charged ADS620 QDs. This preliminary knowledge will serve as a basis for new CE immunoassay studies of QD‐biomolecule conjugates and their immunocomplexes with target analytes.
Transcriptional control of oligodendrogenesis
Authors: Nicolay Danette J. , Doucette J. Ronald , Nazarali Adil J. 
Published: July 2007

AbstractOligodendrocytes (OGs) assemble the myelin sheath around axons in the central nervous system. Specification of cells into the OG lineage is largely the result of interplay between bone morphogenetic protein, sonic hedgehog and Notch signaling pathways, which regulate expression of transcription factors (TFs) dictating spatial and temporal aspects of oligodendrogenesis. Many of these TFs and others then direct OG development through to a mature myelinating OG. Here we describe signaling pathways and TFs that are inductive, inhibitory, and/or permissive to OG specification and maturation. We develop a basic transcriptional network and identify similarities and differences between regulation of oligodendrogenesis in the spinal cord and brain. © 2007 Wiley‐Liss, Inc.
Spatial arrangement of microglia in the mouse hippocampus: A stereological study in comparison with astrocytes
Authors: Jinno Shozo , Fleischer Frank , Eckel Stefanie , Schmidt Volker , Kosaka Toshio 
Published: July 2007

AbstractMicroglia are classically considered to be immune cells in the brain, but have now been proven to be involved in neuronal activity as well. Here we stereologically analyzed the spatial arrangement of microglia in the mouse hippocampus. First, we estimated the numerical densities (NDs) of microglia identified by ionized calcium‐binding adaptor molecule 1 (Iba1). Despite that microglia appeared to be evenly distributed throughout the hippocampal area, the NDs demonstrated significant dorsoventral, interregional, and interlaminar differences. Briefly, the NDs in the ventral hippocampus were significantly lower in the CA3 region than in the CA1 region and dentate gyrus, although no interregional differences were detectable in the dorsal hippocampus. Both in the CA1 and CA3 regions, the NDs were significantly higher in the stratum lacunosum‐moleculare than in the remaining layers. Next, we investigated the spatial patterns of distribution of Iba1‐labeled microglia and S100β‐labeled astrocytes. So far as we examined, the somato–somatic contacts were not seen among microglia or among astrocytes, whereas the close apposition between microglia and astrocytes were occasionally detected. The 3D point process analysis showed that the spatial distribution of microglia was significantly repulsive. Because the statistical territory of single microglia was larger than that estimated from process tracing, they are not likely to touch each other with their processes. Astrocytes were distributed slightly repulsively with overlapping areas. The 3D point process analysis also revealed a significant spatial attraction between microglia and astrocytes. The present findings provide a novel anatomical basis for glial research. © 2007 Wiley‐Liss, Inc.
Gastric cancer cells in collagen gel matrix: Three‐dimensional growth and differential expression of adhesion molecules (CD44s, CD54, E‐cadherin)
Authors: Jia Qian , Feng Meifu , Wang Yun , Xue Shaobai 
Published: July 2007

AbstractTo characterize the growth of human gastric cancer cells in collagen gel matrix and adhesive status of the cells in comparison with conventional monolayer cells. Three kinds of human gastric cancer cell lines (BGC823, SGC7901, and MKN28) were cultured alone or co‐cultured with normal human fibroblasts in collagen gel matrix, and their cell cycle, metabolic function, and the expression of adhesive molecules (CD44s, CD54, and E‐cadherin) were analyzed by flow cytometry or other methods. Two of three cell lines (BGC823 and SGC7901) and their co‐cultures showed multilayer growth in collagen gel matrix, and their growth and metabolism rate became slow and the cell adhesion molecules (CAMs) expression was down regulated. Gastric cancer cell alone or with fibroblasts in collagen gel matrix showed distinct growth feature when compared with monolayer cells, which represent two kinds of different experimental models. BGC823 and SGC7901 cells growing in three‐dimension may recur some characteristics of their original solid tumor in vivo with the invasive or metastatic ability. According to different aims, it should pay great care in choice of experimental model to get more reasonable results. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Supported phospholipid bilayers as a platform for neural progenitor cell culture
Authors: Thid D. , Holm K. , Eriksson P.S. , Ekeroth J. , Kasemo B. , Gold J. 
Published: July 2007

AbstractSupported phospholipid bilayers constitute a biomimetic platform for cell behavior studies and a new approach to the design of cell culture substrates. Phosphocholine bilayers are resistant to cell attachment, but can be functionalized with bioactive molecules to promote specific cell interactions. Here, we explore phosphocholine bilayers, functionalized with the laminin‐derived IKVAV pentamer, as substrates for attachment, growth, and differentiation of neural progenitor cells (AHPs). By varying peptide concentration (0–10%), we discovered a strongly nonlinear relationship between cell attachment and IKVAV concentration, with a threshold of 1% IKVAV required for attachment, and saturation in cell binding at 3% IKVAV. This behavior, together with the 10‐fold reduction in cell attachment when using a jumbled peptide sequence, gives evidence for a specific interaction between IKVAV and its AHP cell‐surface receptor. After 8 days in culture, the peptide‐functionalized bilayers promoted a high degree of cell cluster formation. This is in contrast to the predominant monolayer growth, observed for these cells on the standard laminin coated growth substrates. The peptide‐functionalized bilayer did not induce differentiation levels over those observed for the laminin coated substrates. These results are promising in that peptide‐functionalized bilayers can allow attachment and growth of stem cells without induction of differentiation. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Controlled degradation of multilayered poly(lactide‐co‐glycolide) films using electron beam irradiation
Authors: Chia N.K. , Venkatraman S. S. , Boey F.Y.C. , Cadart S. , Loo J.S.C. 
Published: July 2007

AbstractThe ability to undergo predictable and controlled degradation allows biopolymers to release prescribed dosages of drugs locally over a sustained period. However, the bulk or homogeneous degradation of some of these polymers like poly(L‐lactide) (PLLA) and poly(lactide‐co‐glycolide) (PLGA) work against a better controlled release of the drugs. Inducing the polymers to undergo surface erosion or layer‐by‐layer degradation could provide a better process of controlled drug release from the polymers. This study has demonstrated that surface erosion degradation of PLGA is possible with the use of a multilayer film system, with PPdlLGA [plasticized poly(D,L‐lactide‐co‐glycolide) (PdlLGA)] as the surface layers and poly(L‐lactide‐co‐glycolide) as the center layer. The use of the more hydrophilic PPdlLGA as the surface layer resulted in a faster degradation of the surface layers compared to the center layer, thus giving a surface erosion degradation effect. The rate of surface degradation could also be controlled with electron beam (e‐beam) radiation, where e‐beam irradiation was shown to alter the degradation time and onset of polymer mass loss. It was also shown that the more highly irradiated PPdlLGA surface layers had an earlier onset of mass loss, which resulted in a faster reduction in overall film thickness. The ability to control the rate of film thickness reduction with different radiation dose promises a better controlled release of drugs from this multilayer PLGA film system. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Modification of Ti implant surface for cell proliferation and cell alignment
Authors: Zhao Jia Ming , Tsuru Kanji , Hayakawa Satoshi , Osaka Akiyoshi 
Published: July 2007

AbstractSurface properties of implants are the keys for ensuring their long‐lasting anchorage to the tissue. This study aims to develop a novel implant surface microstructure with high biocompatibility and ability of guided tissue formation. By a photolithography method, gold (Au) grids (1 × 1 mm2 square lattices, 10 μm in grid‐line width) were deposited on titanium substrates. They were oxidized with H2O2 solution to yield titania (anatase) layer, and the Au grid formed channels due to larger molar volume of anatase than Ti. L‐Cysteine and type I collagen were then immobilized on them to yield the target substrates, CHT–Au–cys–col. Apatite deposited within 3 days when they were soaked in Kokubo's simulated body fluid, regardless of the protein coating, but not on the bottom of the Au channel. Osteoblast‐like MC3T3‐E1 cells were cultured on the CHT–Au–cys–col substrates, showing that (1) the cysteine–collagen coating promoted cell attachment and proliferation, and (2) the Au channels were filled with the cells which were aligned along the channel direction and were connected to the neighboring cells as well as attached to the channel wall with cytoplasmic extensions. The results thus ensured filopodial guidance for the substrates. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Water absorbing and antibacterial properties of N‐isopropyl acrylamide grafted and collagen/chitosan immobilized polypropylene nonwoven fabric and its application on wound healing enhancement
Authors: Wang Chyung‐Chyung , Su Ching‐Hua , Chen Cheng‐Chi 
Published: July 2007

AbstractA durable sandwich wound dressing system with high liquid absorbing, biocompatibility, and antibacterial properties was designed. Various solution weight ratios of collagen to chitosan were used to immobilize on the polypropylene nonwoven fabric, which were pregrafted with acrylic acid (AA) or N‐isopropyl acrylamide (NIPAAm) to construct a durable sandwich wound dressing membrane with high water absorbing, easy removal, and antibacterial activity. Swelling properties and antibacterial activity of the membranes were measured, and wound healing enhancement by skin full‐thickness excision on animal model was examined. The results indicated that NIPAAm‐grafted and collagen/chitosan‐immobilized polypropylene nonwoven fabric (PP‐NIPAAm‐collagen‐chitosan) showed a better healing effect than AA‐grafted and collagen/chitosan‐immobilized polypropylene nonwoven fabric (PP‐AA‐collagen‐chitosan). The wound treated with PP‐NIPAAm‐collagen‐chitosan demonstrated the excellent remodeling effect in histological examination with respect to the construction of vein, epidermis, and dermis at 21 days after skin injury. The values of water uptake and water diffusion coefficient for PP‐NIPAAm‐collagen‐chitosan were higher than that for PP‐AA‐collagen‐chitosan under a given solution weight ratio of collagen/chitosan. Both PP‐NIPAAm‐collagen‐chitosan and PP‐AA‐collagen‐chitosan demonstrated antibacterial activity. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Anisomycin abrogates repression of protooncogene c‐fos transcription in E1A + cHa‐ras‐transformed cells through activation of MEK/ERK kinase cascade
Authors: Kukushkin Alexander N. , Svetlikova Svetlana B. , Amanzholov Rustam A. , Pospelov Valery A. 
Published: July 2007

AbstractWe have previously shown that transcription of immediate‐early c‐fos protooncogene is becoming strongly repressed in rat embryo fibroblasts transformed by oncogenes E1A and cHa‐ras, so that serum only slightly stimulated c‐fos transcription in these cells in contrast to high level of c‐fos activation in non‐transformed REF52 cells. Here we showed that stress‐inducing agent anisomycin was able to override the c‐fos repression and to induce c‐fos transcription in E1A + ras transformants. In vitro kinase assay data demonstrated that anisomycin increased phosphorylation of transactivation domain of Elk‐1 transcription factor—a key regulator of inducible c‐fos transcription. Importantly, this activation was mediated through up‐regulation of MEK/ERK but not stress‐kinase cascades JNK or p38. The activating effect of anisomycin on c‐fos transcription could be abrogated by a prior treatment with N‐acetyl‐L‐cysteine. This indicates that anisomycin potentiates generation of reactive oxygen species (ROS), which, in turn, can modulate the activity of MAP kinase‐specific phosphatases (MKPs). As anisomycin did not cause acetylation of nucleosome core histones, the present work focuses on the molecular mechanisms mediating the HDAC‐independent induction of IEG c‐fos by anisomycin in E1A + cHa‐ras‐transformed fibroblasts. J. Cell. Biochem. 103: 1005–1012, 2008. © 2007 Wiley‐Liss, Inc.
Tricycloalternarene derivatives produced by an endophyte Alternaria alternata isolated from Maytenus hookeri
Authors: Qiao Li‐Rui , Yuan Lin , Gao Jin‐Ming , Zhao Pei‐Ji , Kang Qian‐Jin , Shen Yue‐Mao 
Published: July 2007

AbstractA new tricycloalternarene derivative, named tricycloalternarenal (1), together with three known compounds was isolated from the cultures of Alternaria alternata, an endophytic fungus in the leaves of the plant Maytenus hookeri (Celastraceae). Structure of 1 was established as (2E)‐6‐(3,3a,5,6,7,8,9,9a‐octahydro‐5‐hydroxy‐3a‐methyl‐8‐oxo‐cyclo‐penta[b]chromen‐1‐yl)‐2‐methylhept‐2‐enal by spectroscopic methods, including 2D‐NMR experiments. The remaining compounds were determined as tricycloalternarene‐3b (2), alterperylenol (3), and dihydroalterperylenol (4). (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of a Pleurotus ostreatus fruiting body‐specific hydrophobin gene, Po.hyd
Authors: Ma Aimin , Shan Linjun , Wang Nianjiu , Zheng Liesheng , Chen Liguo , Xie Bijun 
Published: July 2007

AbstractHydrophobins are a family of small, moderately hydrophobic proteins with eight cysteine residues arranged in a conserved pattern. A full‐length cDNA, designated Po.hyd, corresponding to a hydrophobin gene of Pleurotus ostreatus was obtained in our previous work. The Po.hyd gene contains a 333 bp open reading frame (ORF), which is interrupted by two typical classI introns. There was no consensus signal for a polyA tail detected in the 3′untranslated region. However, an analogous T‐ or TG‐rich motif was observed that probably influence the formation of the mRNA 3′ end. We assign the putative Po.HYD protein to the classI hydrophobins since its sequence arrangement and hydropathy pattern has a high consensus to other known class I hydrophobins. Northern analysis showed that the Po.hyd gene was abundantly expressed throughout the fruiting process (from primordium to mature fruiting body) but silenced during vegetative growth of the mycelium. Southern blot analysis showed Po.hyd to be a single copy gene in the genome of dikaryotic strain likely to locate at the same locus within the two parental genomes. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phosphate supply and arsenate toxicity in ectomycorrhizal fungi
Authors: Chen Serena H. , Tibbett Mark 
Published: July 2007

AbstractThree species of ectomycorrhizal fungi (Hebeloma crustuliniforme, Suillus variegatus and Cenococcum geophilum) were grown in axenic culture amended with range of AsO43– concentration under three different PO43– regimes. The fungi exhibited different growth responses to AsO43– that varied with PO43– concentration. Suillus variegatus showed the greatest sensitivity to AsO43–, with growth almost completely inhibited in the presence of AsO43– under the lower two PO43– treatments. Under the highest PO43– treatment however, growth was enhanced and S. variegatus was able to persist at AsO43– concentrations of up to 4 mM. Hebeloma crustuliniforme also showed high sensitivity to AsO43– especially at low PO43– concentration. The two higher PO43– treatments had an ameliorating effect on AsO43– toxicity in H. crustuliniforme. This demonstrates the ability of PO43– to alleviate AsO43– toxicity. The response from S. variegatus and H. crustuliniforme, both basidiomycetes, was in contrast to the ascomycete C. geophilum. This fungus demonstrated tolerance to AsO43– when grown in culture solution and PO43– did not have an ameliorating effect on AsO43– toxicity in C. geophilum. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A simple model for estimating the maximum intensity of nocturnal urban heat Island
Authors: Montávez Juan Pedro , González‐Rouco Jesús Fidel , Valero Francisco 
Published: July 2007

AbstractSeveral studies have tried to determine the empirical relationships between the maximum urban heat island (UHI) intensity and factors such as the city size taking the number of inhabitants as indicator, the geometry of the city (i.e. the H/W ratio), meteorological factors, etc. On the other hand, numerical models have also been formulated to understand the main factors contributing to the formation of UHI.In this work, a set of empirical equations for determining the maximum of the UHI is presented. The equations have been fitted to the output results of a set of experiments performed by a canyon model (Montávez et al., 2000a), investigating the main factors contributing to the nocturnal UHI. The input parameters are the thermal inertia of rural and urban materials, the H/W ratio and the increase in long‐wave sky radiation due in part to pollution over cities. The results obtained are able to reproduce most of UHI intensity maxima around the world. Copyright © 2007 Royal Meteorological Society
Classification of daily abundant rainfall patterns and associated large‐scale atmospheric circulation types in Southern Portugal
Authors: Fragoso M. , Tildes Gomes P. 
Published: July 2007

AbstractThe aim of this study is to carry out two objective classifications concerning the occurrence of episodes of heavy rainfall in Southern Portugal. The first one seeks to define the main spatial distribution patterns associated with abundant rainfall days in this region. Using a 15‐year (from October 1983 to April 1998) precipitation data base corresponding to 98 sites in Southern Portugal, a sample is established by extracting the precipitation days in which the threshold of 40 mm/24 h was exceeded in three or more stations, yielding a total of 199 days. It is found that the Algarve region is the one where episodes of heavy rainfall are most frequent and which exhibits the strongest torrential character. The highest frequency of days with heavy rain occurs in the fall and in the early part of the winter. Through the combined use of principal component analysis (PCA) and k‐means clustering, four different rainfall patterns are identified, and each one exhibits specific characteristics.The second classification is obtained using the same computational method (PCA coupled with k‐means) and seeks to define the fundamental large‐scale atmospheric circulation types associated with abundant rainfall in the region, based on sea level pressure (SLP) data. The data was collected from the NCEP/NCAR Reanalysis dataset, taking SLP as the most discriminating variable. Five circulation types are thus obtained, indicating considerable diversity among the large‐scale atmospheric circulation conditions that are conducive to the occurrence of heavy rainstorms in Southern Portugal.The article concludes by discussing the main links between the two classification schemes, in order to ascertain the influence of the large‐scale atmospheric circulation upon the spatial distribution patterns of heavy precipitation episodes. Copyright © 2007 Royal Meteorological Society
A 10‐year spatial climatology of squall line storms across Oklahoma
Authors: Hocker James E. , Basara Jeffrey B. 
Published: July 2007

AbstractSevere thunderstorms are an important and relatively common component of the annual weather across the State of Oklahoma. Such weather brings hazardous features such as, large hail, damaging winds, and tornadoes, while also providing beneficial precipitation vital to the state's agricultural and hydrological needs. In any given year, severe weather activity is dictated by seasonal and monthly changes in atmospheric conditions, which frequently determine the type and severity of subsequent storms.This study focuses on a 10‐year period between 1994 and 2003 to quantify the spatial and temporal characteristics of severe squall line storms across Oklahoma. A squall line is a linearly organized set of storms that has a sharp radar reflectivity gradient at its leading edge typically followed by a less intense stratiform region. Squall line storms are one of the most significant storm modes observed in Oklahoma due to their large aerial extent, long durations, high winds, heavy rains, and hail. For this study, geographic information systems (GIS) were used to store geo‐referenced storm data and spatially analyse storm events across varying timescales. The analysis revealed that squall lines were most predominant across eastern Oklahoma with a decreasing westward gradient. The annual averaged storm track was from the west to east, while the monthly mean squall line tracks were oriented from southwest to northeast from January through April, from west to east during May, from northwest to southeast from June through September, and from southwest to northeast through the end of the year. In addition, high‐resolution analyses of squall line initiation and termination locations revealed important geographical variability in typical storm lifecycle. Copyright © 2007 Royal Meteorological Society
Vertical variations of rain intensity in different rainy periods in and around Bangladesh derived from TRMM observations
Authors: Islam Md. Nazrul , Uyeda Hiroshi 
Published: July 2007

AbstractIn this paper, differences in rain intensity in and around Bangladesh during various rainy periods are described. The data were obtained from tropical rainfall measuring mission (TRMM) ‐2A25, ‐3B42 and ‐3B43. The version 5 (V5) 3B42 daily products overestimated rainfall in pre‐monsoon and post‐monsoon periods but underestimated it in the monsoon period compared with rain‐gauge data. The version 6 (V6) daily products reduced the over‐ and under‐estimation of rainfall. On the basis of the analysed rainfall characteristics in different rainy periods, the 2A25 data was analysed to reveal the vertical variations of rain intensity. Pre‐monsoon rainfall was characterized by convective rain with strong intensity upto high altitudes and high echo tops that usually occurred over land and not over the Bay of Bengal. In contrast, during monsoon, intense rain occurred over the Bay of Bengal and land; however, the existence of strong and high echo tops was less significant than that during the pre‐monsoon period. The radar echo tops and the height of strong rain intensity measured in the post‐monsoon period were lower than those obtained in the monsoon period. Copyright © 2007 Royal Meteorological Society