bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protein Engineering – An Option for Enzymatic Biofuel Cell Design
Authors: Güven Güray , Prodanovic Radivoje , Schwaneberg Ulrich 
Published: February 2010

AbstractThis review summarizes and discusses from a protein engineering point of view strategies to improve performances of biocatalysts in enzymatic biofuel cells. Emphasis will be given on biocatalysts employed in biofuel cells and protein engineering principles for achieving an efficient electrical communication between electrode and biocatalyst(s). Biocatalyst engineering by Rational Design and Directed Evolution offers opportunities to redesign and to improve biocatalysts for biofuel cell applications instead of accepting insufficient biocatalyst properties as unalterable limitations in the development of biofuel cells.
Grafted 2‐chloroethylphosphonic acid on inorganic supports used as flame retardant for unsaturated polyester resins
Authors: Ilia Gheorghe , Drehe Madalina 
Published: February 2010

AbstractFlame retardants (FRs) are used for in protection against fire. Organic–inorganic hybrids could become one of the most promising FR solution in the future. In this paper, the synthesis, the characterization and the use as FRs and filler of grafted titania and alumina with 2‐chloroethylphosphonic acid are presented. These hybrids contain 3.8–3.24% P and have good flame retardance when they are incorporated into unsaturated polyester resins. Alumina treated with 2‐chloroethylphosphonic acid performed better than titania. The advantage of this approach is the use of these hybrid materials as filler and FR, in the same time, and the increase in flame retardancy by synergistic effect between alumina phosphorus and chlorine, for unsaturated polyester resins. Copyright © 2010 John Wiley & Sons, Ltd.
Radiation and magnetic field effects on the unsteady mixed convection flow of a second grade fluid over a vertical stretching sheet
Authors: Hayat T. , Qasim M. 
Published: February 2010

AbstractThis present analysis discusses the mixed convection boundary layer flow of a magnetohydrodynamic second grade fluid over an unsteady permeable stretching sheet. The time‐dependent stretching velocity and the surface temperature are chosen. Series solutions of the governing boundary value problems are obtained by employing homotopy analysis method. Convergence of the obtained solution is explicitly discussed. The dependence of velocity and temperature profiles on the various quantities is shown and discussed by plotting graphs. Skin friction coefficient and the local Nusselt number tabulated and analyzed. Copyright © 2010 John Wiley & Sons, Ltd.
Pattern of δ13Ccarb and implications for geological events during the Permian‐Triassic transition in South China
Authors: Cao C. Q. , Yang Y. C. , Shen S. Z. , Wang W. , Zheng Q. F. , Summons R. E. 
Published: February 2010

AbstractData from five marine sections across the Permian‐Triassic boundary in southern China reveal a pattern of 13C‐depleted carbonate (δ13Ccarb) in different facies spanning carbonate platform to lower slope. A gradual decrease of δ13Ccarb is evident in all sections and matched by an opposing change in 87Sr/86Sr from the Late Permian to the Induan (Early Triassic). These complementary trends in strontium and carbon isotope data imply an extended period of enhanced continental uplift and weathering of silicates and organic matter across the Permian‐Triassic event boundary (PTEB). A pronounced sharp drop of δ13Ccarb at the PTEB is most recognizable in the upper ramp environment of Meishan, occurs weakly in shallow water environments and cannot be discerned in the deepest water setting. We propose that this pattern reflects an enhancement of stratified‐ocean conditions in the immediate aftermath of the latest Permian transgression. The sharp drop in δ13Ccarb at the PTEB in the platform ramp environments likely resulted from the depth‐selective calcification of 13C‐depleted dissolved inorganic carbon (DIC) formed by respiration of organic matter including, perhaps, methane. Indeed, massive volcanism at the PTEB would have enhanced eutrophication and stratification thereby slowing the mixing of 13C‐depleted DIC into deeper‐water environments. Copyright © 2010 John Wiley & Sons, Ltd.
No excess risk of follicular lymphoma in kidney transplant and HIV‐related immunodeficiency
Authors: Vajdic Claire M. , van Leeuwen Marina T. , Turner Jennifer J. , McDonald Ann M. , Webster Angela C. , McDonald Stephen P. , Chapman Jeremy R. , Kaldor John M. , Grulich Andrew E. 
Published: February 2010

AbstractSubtype‐specific incidence patterns in populations at high risk of lymphoma offer insight into lymphomagenesis. The incidence profiles for the 2 most common non‐Hodgkin lymphoma subtypes were compared for 2 immunodeficient populations, adults receiving a kidney transplant 1982–2003 (n = 7,730) or diagnosed with human immunodeficiency virus (HIV) infection 1982–2004 (n = 17,175). National, population–based registries were linked and standardized incidence ratios (SIRs) were computed for each cohort and lymphoma subtype. Risk of diffuse large B‐cell lymphoma was significantly increased after transplantation (SIR 17.83, 95% CI: 13.61–22.95) and after HIV infection (SIR 58.81, 95% CI: 52.59–65.56). Rates of follicular lymphoma (FL) were neither significantly increased nor decreased in transplant recipients (SIR 0.82, 95% CI: 0.10–2.96) and in people with HIV (SIR 1.25, 95% CI: 0.41–2.91). The findings argue against an infectious or other immunodeficiency‐related etiology for FL and clearly differentiate it from diffuse large B‐cell lymphoma.
Gastric cancer occurrence in preneoplastic lesions: A long‐term follow‐up in a high‐risk area in Spain
Authors: González Carlos A. , Pardo Maria Luisa , Ruiz Liso Juan Maria , Alonso Pablo , Bonet Catalina , Garcia Raul M. , Sala Núria , Capella Gabriel , Sanz‐Anquela José Miguel 
Published: February 2010

AbstractThere are no established criteria to classify patients into high or low risk of progressing to gastric cancer (GC). The aim of the study was to identify predictors of GC occurrence among patients with gastric preneoplastic lesions. A prospective and retrospective follow‐up study was carried out in a province in Spain with one of the highest risk of GC. The study included 478 patients who underwent gastric biopsy in 1988–1994 with diagnoses of normal mucosa, nonatrophic gastritis (NAG), non‐metaplastic multifocal atrophic gastritis (MAG) and complete or incomplete intestinal metaplasia (IM) and who accepted to undergo a new biopsy during 2005–2007 or had an event during follow up. Inter‐ and intra‐observer variability of histological diagnosis was assessed. Analysis was done using Cox proportional hazards risk (HR) models. The mean age of the patients was 50 years, 47% were males and the mean follow‐up time was 12.8 years. During follow‐up, 23 GC (4.8%) were diagnosed (21 adenocarcinomas and 2 lymphomas) with an incidence of 3.77 per 1,000 person per year. The incidence rate of GC for those with incomplete IM was 16.5 per 1,000 person years. Out the 21 adenocarcinomas, 16 had an incomplete IM in the baseline diagnosis. Incomplete IM (HR 11.3; 95% CI 3.8–33.9) and a family history of GC (HR 6.1; 95% CI 1.7–22.4) were the strongest risk factors for gastric adenocarcinoma. Subtyping of IM and family history of GC may be useful for the identification of high‐risk patients who need more intensive surveillance.
Cancer antineovascular therapy with liposome drug delivery systems targeted to BiP/GRP78
Authors: Katanasaka Yasufumi , Ishii Takayuki , Asai Tomohiro , Naitou Hirotaka , Maeda Noriyuki , Koizumi Fumiaki , Miyagawa Shinichi , Ohashi Norio , Oku Naoto 
Published: February 2010

AbstractAngiogenesis is crucial for tumor growth and hematogenous metastasis. Specifically expressed and functional protein molecules in angiogenic endothelial cells, especially on the plasma membrane, may be molecular targets for antiangiogenic drugs and drug delivery systems (DDS) in cancer therapy. To discover such target molecules, we performed subcellular proteome analysis of human umbilical vein endothelial cells (HUVECs) treated with or without vascular endothelial growth factor (VEGF) using 2‐dimensional difference in‐gel electrophoresis (2D‐DIGE) and matrix‐assisted laser desorption/ionization tandem time‐of‐flight mass spectrometry (MALDI‐TOF/TOF‐MS). Among the identified proteins, BiP/GRP78, a molecular chaperone, was highly expressed in the membrane/organelle fraction of HUVECs after VEGF treatment. The involvement of BiP in VEGF‐induced angiogenesis was examined by RNA interference. BiP knockdown significantly suppressed VEGF‐induced endothelial cell proliferation and VEGF‐induced phosphorylation of extracellular‐regulated kinase 1/2, phospholipase C‐γ, and VEGF receptor‐2 in HUVECs. Cell surface biotinylation analysis revealed that the cell surface expression of BiP was elevated in VEGF‐activated HUVECs. Aiming to apply BiP to a target molecule in liposomal DDS, we developed liposomes modified with the WIFPWIQL peptide, which has been shown to bind to BiP, and investigated its potential for cancer therapy. The WIFPWIQL‐modified liposomes (WIFPWIQL liposomes) were significantly taken up by VEGF‐activated HUVECs as compared to peptide‐unmodified liposomes. WIFPWIQL liposomes appeared to accumulate in tumor endothelial cells in vivo. WIFPWIQL liposomes containing doxorubicin significantly suppressed tumor growth and prolonged the survival of colon26 NL‐17 carcinoma cell‐bearing mice. In summary, BiP may regulate VEGF‐induced endothelial cell proliferation through VEGFR‐2‐mediated signaling and be an effective target molecule for cancer antineovascular therapy.
Keratin 6 expression correlates to areas of squamous differentiation in multiple independent isolates of As+3‐induced bladder cancer
Authors: Cao Ling , Zhou Xu Dong , Sens Mary Ann , Garrett Scott H. , Zheng Yun , Dunlevy Jane R. , Sens Donald A. , Somji Seema 
Published: February 2010

AbstractThis laboratory has shown that arsenite (As+3) exposure can cause the malignant transformation of the UROtsa human urothelial cell line. This single isolate formed subcutaneous tumors with a histology similar to human urothelial cell carcinoma. The tumors also displayed areas of squamous differentiation of the urothelial cells, an infrequent but known component of human bladder cancer. In the present study, five additional independent isolates of As+3‐transformed urothelial cells were isolated and each was shown to produce subcutaneous urothelial cell tumors with a characteristic histology very similar to those described in the initial report. That there were underlying phenotypic differences in the six independent isolates was demonstrated when they were assessed for their ability to form tumors within the peritoneal cavity. It was shown that two isolates could form hundreds of small peritoneal tumor nodules, one isolate a moderate number of tumor nodules, and three isolates no or only one tumor nodule. The peritoneal tumors were also characterized for their degree of squamous differentiation of the urothelial cells and, while areas of squamous differentiation could be found, such differentiation was substantially reduced compared to subcutaneous tumors. Immunostaining for keratin 6 was tested as a potential marker for malignant urothelial cells that had undergone squamous differentiation. Keratin 6 was shown to consistently stain only cells having some evidence of squamous differentiation. Keratin 16 was shown to follow the staining pattern of keratin 6. The isolates and tumor heterotransplants were all examined for keratin 6, 16 and 17 mRNA and protein expression. Copyright © 2010 John Wiley & Sons, Ltd.
Haemo‐ and cytocompatibility of bioresorbable homo‐ and copolymers prepared from 1,3‐trimethylene carbonate, lactides, and ϵ‐caprolactone
Authors: Yang Jian , Liu Feng , Tu Song , Chen Yuanwei , Luo Xianglin , Lu Zhiqian , Wei Jia , Li Suming 
Published: February 2010

AbstractA series of bioresorbable polymers were prepared by ring‐opening polymerization of L‐lactide (LLA), DL‐lactide (DLLA), ϵ‐caprolactone (CL) and 1,3‐trimethylene carbonate (TMC), using low toxic zinc lactate as catalyst. The various PLLA, PTMC, PCL homopolymers, and PLLA‐TMC, PDLLA‐TMC, PCL‐TMC copolymers with 50/50 molar ratios were characterized by using analytical techniques such as proton nuclear magnetic resonance, gel permeation chromatography, tensiometer, and differential scanning calorimetry. The haemo‐ and cyto‐compatibility were investigated in order to evaluate the potential of the polymers as coating material in drug eluting stents. Haemolysis tests show that all the homo‐ and copolymers present very low haemolytic ratios, indicating good haemolytic properties. Adhesion and activation of platelets were observed on the surface of PLLA, PCL, PLLA‐TMC, and PDLLA‐TMC films, while less platelets and lower activation were found on PTMC. The most interesting results were obtained with PCL‐TMC which exhibited the lowest degree of activation with few adhered platelets, in agreement with its outstanding anticoagulant properties. Both indirect and direct cytocompatibility studies were performed on the polymers. The relative growth ratio data obtained from the liquid extracts during the 6‐day cell culture period indicate that all the polymers present very low cytotoxicity. Microscopic observations demonstrate adhesion, spreading and proliferation of human umbilical vein endothelial cells ECV304. Therefore, it is concluded that these bioresorbable polymers, in particular PCL‐TMC, are promising candidate materials as drug loading coating material in drug eluting stents. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res 2010
Characterization of cyclic acetal hydroxyapatite nanocomposites for craniofacial tissue engineering
Authors: Patel Minal , Patel Ketan J. , Caccamese John F. , Coletti Domenick P. , Sauk John J. , Fisher John P. 
Published: February 2010

AbstractCyclic acetal hydrogels are a novel group of biomaterials which may facilitate osteogenic differentiation of encapsulated bone marrow stromal cells (BMSCs) because of their neutral degradation products. Here, we have incorporated hydroxyapatite nanoparticles within cyclic acetal hydrogels to create cyclic acetal nanocomposites for craniofacial tissue engineering applications. We hypothesized that inclusion of nanosized hydroxyapatite particles within cyclic acetal hydrogels would upregulate osteogenic signal expression of encapsulated BMSCs, due to enhanced cell adhesion, and therefore promote osteodifferentiation. Experimental nanocomposite groups consisted of lower (5 ng/mL) and higher (50 ng/mL) concentrations of nanoparticles. The nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy, and energy dispersive spectroscopy. Swelling parameters of hydrogels in the presence of nanoparticles was studied. Osteoblastic differentiation was characterized by alkaline phosphatase (ALP) and osteocalcin (OC) expression, whereas endogenous osteogenic signal expression was characterized by morphogenetic protein‐2 (BMP‐2) expression. Finally, immunohistochemistry was performed to detect the presence of OC at the protein level. Results indicated that hydroxyapatite nanoparticles were uniformly distributed throughout the hydrogels and did not affect material properties of the gels. Viability of cells was not affected by nanoparticle concentration, and BMP‐2 and OC mRNA expression was enhanced in the presence of nanoparticles. However, a difference in BMP‐2, ALP, and OC mRNA expression was not noted between the lower and higher concentrations of nanoparticles. This work demonstrates that inclusion of hydroxyapatite nanoparticles within a cyclic acetal nanocomposite hydrogel may enhance BMSC differentiation by promoting endogenous osteogenic signal expression. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res 2010
Effect of chromium and cobalt ions on the expression of antioxidant enzymes in human U937 macrophage‐like cells
Authors: Tkaczyk Cathy , Huk Olga L. , Mwale Fackson , Antoniou John , Zukor David J. , Petit Alain , Tabrizian Maryam 
Published: February 2010

AbstractThe main concern associated with metal‐on‐metal (MM) hip prosthesis is the presence of metal ions, mainly chromium (Cr) and cobalt (Co), which are found both systemically and locally in the organism of patients. Previous studies revealed that Cr(III) and Co(II) ions could induce damages to proteins in macrophage‐like cells in vitro, probably through the formation of reactive oxygen species (ROS). We then hypothesized that these ions can modify the expression of antioxidant enzymes in these cells. Results showed that Cr(VI) induced the protein expression of Mn‐superoxide dismutase, Cu/Zn‐superoxide dismutase, catalase, glutathione peroxidase, and heme oxygenase‐1 (HO‐1) but had no effect of the expression of their mRNA. Cr(III) have no effect on the expression of all these antioxidant enzymes. Co(II) induced the expression of both protein and mRNA of HO‐1 only. In conclusion, results showed that Cr(VI), Cr(III), and Co(II) had differential effects on the expression of antioxidant enzymes in macrophage‐like cells in vitro. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res 2010
Quantitative analysis of adhesive resin in the hybrid layer using Raman spectroscopy
Authors: Zou Yuan , Armstrong Steven R. , Jessop Julie L. P. 
Published: February 2010

AbstractThe objective was to determine absolute molar concentration of adhesive resin components in the hybrid layer by establishing methods based on Raman spectroscopy fundamentals. The hybrid layer was treated as a three‐component system consisting of collagen and an adhesive resin containing two monomers. Adhesive standard specimens and Raman peak area ratios obtained with a 785 nm excitation wavelength were used to construct separate calibration curves for comonomer relative molar concentration and Bis‐GMA absolute molar concentration. As collagen and water had no measurable peaks in the fingerprint region, a dilution coefficient Kj was defined to describe their impact on Raman peak area and to calculate HEMA absolute molar concentration. Methodology was validated using an analogous system containing acetone/ethanol/water. The absolute molar concentration of Bis‐GMA and HEMA decreased 87% and 83%, respectively, from the top quarter to the middle of the hybrid layer. Additionally, less Bis‐GMA penetrated the hybrid layer than HEMA, as indicated by the ∼20% decrease in comonomer molar concentration ratio between the adhesive resin layer and the top half of the hybrid layer. Lack of complete monomer infiltration will further challenge dentin‐adhesive bond longevity. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Collagen type I hydrogel allows migration, proliferation, and osteogenic differentiation of rat bone marrow stromal cells
Authors: Hesse Eric , Hefferan Theresa E. , Tarara James E. , Haasper Carl , Meller Rupert , Krettek Christian , Lu Lichun , Yaszemski Michael J. 
Published: February 2010

AbstractHydrogels are potentially useful for many purposes in regenerative medicine including drug and growth factor delivery, as single scaffold for bone repair or as a filler of pores of another biomaterial in which host mesenchymal progenitor cells can migrate in and differentiate into matrix‐producing osteoblasts. Collagen type I is of special interest as it is a very important and abundant natural matrix component. The purpose of this study was to investigate whether rat bone marrow stromal cells (rBMSCs) are able to adhere to, to survive, to proliferate and to migrate in collagen type I hydrogels and whether they can adopt an osteoblastic fate. rBMSCs were obtained from rat femora and plated on collagen type I hydrogels. Before harvest by day 7, 14, and 21, hydrogels were fluorescently labeled, cryo‐cut and analyzed by fluorescent‐based and laser scanning confocal microscopy to determine cell proliferation, migration, and viability. Osteogenic differentiation was determined by alkaline phosphatase activity. Collagen type I hydrogels allowed the attachment of rBMSCs to the hydrogel, their proliferation, and migration towards the inner part of the gel. rBMSCs started to differentiate into osteoblasts as determined by an increase in alkaline phosphatase activity after two weeks in culture. This study therefore suggests that collagen type I hydrogels could be useful for musculoskeletal regenerative therapies. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res 2010
The impact of hyaluronic acid oligomer content on physical, mechanical, and biologic properties of divinyl sulfone‐crosslinked hyaluronic acid hydrogels
Authors: Ibrahim Samir , Kang Qian K. , Ramamurthi Anand 
Published: February 2010

AbstractIn recent studies, we showed that exogenous hyaluronic acid oligomers (HA‐o) stimulate functional endothelialization, though native long‐chain HA is more bioinert and possibly more biocompatible. Thus, in this study, hydrogels containing high molecular weight (HMW) HA (1 × 106 Da) and HA‐o mixtures (HA‐o: 0.75–10 kDa) were created by crosslinking with divinyl sulfone (DVS). The incorporation of HA‐o was found to compromise the physical and mechanical properties of the gels (rheology, apparent crosslinking density, swelling ratio, degradation) and to very mildly enhance inflammatory cell recruitment in vivo; increasing the DVS crosslinker content within the gels in general, had the opposite effect, though the relatively high concentration of DVS within these gels (necessary to create a solid gel) also stimulated a mild subcutaneous inflammatory response in vivo and VCAM‐1 expression by endothelial cells (ECs) cultured atop; ICAM‐expression levels remained very low irrespective extent of DVS crosslinking or HA‐o content. The greatest EC attachment and proliferation (MTT assay) was observed on gels that contained the highest amount of HA‐o. The study shows that the beneficial EC response to HA‐o and biocompatibility of HA is mostly unaltered by their chemical derivatization and crosslinking into a hydrogel. However, the study also demonstrates that the relatively high concentrations of DVS, necessary to create solid gels, compromise their biocompatibility. Moreover, the poor mechanics of even these heavily crosslinked gels, in the context of vascular implantation, necessitates the investigation of other, more appropriate crosslinking agents. Alternately, the outcomes of this study may be used to guide an approach based on chemical immobilization and controlled surface‐presentation of both bioactive HA‐o and more biocompatible HMW HA on synthetic or tissue engineered grafts already in use, without the use of a crosslinker, so that improved, predictable, and functional endothelialization can be achieved, and the need to create a mechanically compliant biomaterial for standalone use, circumvented. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010