bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tailoring Cell Behavior on Polymers by the Incorporation of Titanium Doped Phosphate Glass Filler
Authors: Chrzanowski Wojciech , Abou Neel Ensanya A. , Lee Koon‐Y. , Bismarck Alexander , Young Anne M. , Hart Andrew D. , Dalby Matthew J. , Knowles Jonathan C. 
Published: July 2010

AbstractUnderstanding tissue response to materials, to enable modulation and guided tissue regeneration is one of the main challenges in biomaterials science. Nowadays polymers, glasses, and metals dominate as biomaterials. Often native properties of those materials are not sufficient and there is a need to combine them, so as to modify and adjust their properties to the application. The primary aim of this study was to improve cell response to polymer (PLDL) using phosphate glass as filler (titanium doped phosphate glass). As a control β‐tricalcium phosphate (TCP) filler was used. Various concentrations of the filler were used (10–40 vol%). Wetting behavior, ζ‐potentials, mechanical and thermal properties, and human cells response to the materials were evaluated. Results showed that with increase in glass filler loading wettability improved, ζ‐potentials dropped, and increase in stiffness of materials was observed. Importantly cell culture experiments showed more developed and well spread cells on the samples with glass content up to 20 vol%. Cells responded much more positively to the glass filled samples than to TCP filled. However, expression of osteocalcin and osteopontin, proteins that indicate formation of the mineralized structures was positive for all the samples including pure PLDL. It was concluded that due to improved wetting behavior, lower ζ‐potentials, and specific chemistry of the glass filler it was possible to alter cells response, improve bioactivity of the polymer, and vary mechanical properties.
Apatite Deposition on NaOH‐Treated PEEK and UHMWPE Films for Sclera Materials in Artificial Cornea Implants
Authors: Pino Monica , Chrzanowski Wojciech , Fabel Derek , Baklar Mohammed , Stingelin Natalie , Tanner Kathleen E. 
Published: July 2010

AbstractCornea implants consist of a clear optic portion with a surrounding ring known as the skirt, which needs to integrate with the sclera. However, currently used skirt materials lead to poor tissue integration. Improvements in this respect may be achieved by using a bioactive skirt material that adapts to the metabolic activity of the cornea. Polyether etherketone (PEEK) and ultra‐high molecular weight polyethylene (UHMWPE) might provide interesting alternatives, if they can be rendered bioactive. We, therefore, investigated the potential of surface‐modifying PEEK and UHMWPE films through the use of a two‐step treatment. This process involved a suitable chemical surface modification (via immersion in NaOH), with subsequent formation of apatite layers on the polymers' surfaces through exposure to supersaturated simulated body fluid (1.5 SBF). In the present work the effect of 5 and 10 M NaOH on formation of the apatite layer has been investigated with regard to wettability and topography features. In addition, the chemical stability of the apatite layer formed has been analyzed. Our data demonstrate that with an increase in NaOH concentration the wettability of the polymer increased, whilst some changes to the polymer film topography (increase/decrease in roughness) were observed. Most beneficially, the apatite layer that subsequently was grown on pre‐treated PEEK and UHMWPE films through immersion in 1.5 SBF contained phosphate and carbonate ions, in similar ratios to those found in the apatite in dentine, thus, promising good in vivo bioactivity of these polymer films—a necessity if they are to be integrated into artificial cornea.
Dimer‐Based Three‐Dimensional Photonic Crystals
Authors: Hosein Ian D. , Lee Stephanie H. , Liddell Chekesha M. 
Published: July 2010

AbstractThe self‐assembly of polystyrene dimer‐ and spherocylinder‐shaped colloids is achieved via controlled drying on glass and silicon substrates. 3D monoclinic colloidal crystal structures are determined from scanning electron microscopy images of sections prepared using focused ion‐beam (FIB) milling. Full photonic bandgaps between the eighth and ninth bands are found for a systematic range of colloidal dimer shapes explored with respect to the degree of constituent lobe fusion and radius ratio. The pseudogap between bands 2 and 3 for spherocylinder‐based monoclinic crystals is also probed using normal incidence reflection spectroscopy.
Specific Colorimetric Detection of Proteins Using Bidentate Aptamer‐Conjugated Polydiacetylene (PDA) Liposomes
Authors: Jung Yun Kyung , Kim Tae Won , Park Hyun Gyu , Soh H. Tom 
Published: July 2010

AbstractThe development of a bidentate aptamer‐functionalized polydiacetylene (PDA) liposome sensor that is capable of specific colorimetric detection of proteins, directly in complex mixtures (e.g., serum), at sub‐micromolar concentrations within 15 min, is reported. In comparison to sensors fabricated with a single aptamer reagent, the conjugation of bidentate aptamer pairs that recognize two distinct exosites of the target protein (thrombin) to the liposome results in significant enhancements of the sensitivity and the specificity. To elucidate the mechanism behind this enhancement, experimental evidence is presented that suggests that the liposomic aggregation triggered by specific, multi‐site binding to the target protein is responsible for the improved colorimetric response. Since the colorimetric protein sensor does not require any power or instrumentation, it offers a promising approach towards molecular diagnostics at point‐of‐care (POC), especially in low‐resource settings.
Aqueous Ethylenediamine for CO2 Capture
Authors: Zhou Shan , Chen Xi , Nguyen Thu , Voice Alexander K. , Rochelle Gary T. 
Published: July 2010

AbstractAqueous ethylenediamine (EDA) has been investigated as a solvent for CO2 capture from flue gas. EDA can be used at 12 M (mol kg−1 H2O) with an acceptable viscosity of 16 cP (1 cP=10−3 Pa s) with 0.48 mol CO2 per equivalent of EDA. Similar to monoethanolamine (MEA), EDA can be used up to 120 °C in a stripper without significant thermal degradation. Inhibitor A will effectively eliminate oxidative degradation. Above 120 °C, loaded EDA degrades with the production of its cyclic urea and other related compounds. Unlike piperazine, when exposed to oxidative degradation, EDA does not result in excessive foaming. Over much of the loading range, the CO2 absorption rate with 12 M EDA is comparable to 7 M MEA. However, at typical rich loading, 12 M EDA absorbs CO2 2 times slower than 7 M MEA. The capacity of 12 M EDA is 0.72 mol CO2/(kg H2O+EDA) (for P=0.5 to 5 kPa at 40 °C), which is about double that of MEA. The apparent heat of CO2 desorption in EDA solution is 84 kJ mol−1 CO2; greater than most other amine systems.
The Development of a New Type of Rechargeable Batteries Based on Hybrid Electrolytes
Authors: Zhou Haoshen , Wang Yonggang , Li Huiqiao , He Ping 
Published: July 2010

AbstractLithium ion batteries (LIBs), which have the highest energy density among all currently available rechargeable batteries, have recently been considered for use in hybrid electric vehicles (HEVs), plug‐in hybrid electric vehicles (PHEVs), and pure electric vehicles (PEV). A major challenge in this effort is to increase the energy density of LIBs to satisfy the industrial needs of HEVs, PHEVs, and PEVs. Recently, new types of lithium–air and lithium–copper batteries that employ hybrid electrolytes have attracted significant attention; these batteries are expected to succeed lithium ion batteries as next‐generation power sources. Herein, we review the concept of hybrid electrolytes, as well as their advantages and disadvantages. In addition, we examine new battery types that use hybrid electrolytes.
Alpha2beta1 integrin is the major collagen‐binding integrin expressed on human Th17 cells
Authors: Boisvert Marc , Chetoui Nizar , Gendron Steve , Aoudjit Fawzi 
Published: July 2010

AbstractGrowing evidence indicates that collagen‐binding integrins are important costimulatory molecules of effector T cells. In this study, we demonstrate that the major collagen‐binding integrin expressed by human Th17 cells is alpha2beta1 (α2β1) or VLA‐2, also known as the receptor for collagen I on T cells. Our results show that human naïve CD4+ T cells cultured under Th17 polarization conditions preferentially upregulate α2β1 integrin rather than α1β1 integrin, which is the receptor for collagen IV on T cells. Double staining analysis for integrin receptors and intracellular IL‐17 showed that α2 integrin but not α1 integrin is associated with Th17 cells. Cell adhesion experiments demonstrated that Th17 cells attach to collagen I and collagen II using α2β1 integrin but did not attach to collagen IV. Functional studies revealed that collagens I and II but not collagen IV costimulate the production of IL‐17A, IL‐17F and IFN‐γ by human Th17 cells activated with anti‐CD3. These results identify α2β1 integrin as the major collagen receptor expressed on human Th17 cells and suggest that it can be an important costimulatory molecule of Th17 cell responses.
MHC class I molecules exploit the low G+C content of pathogen genomes for enhanced presentation
Authors: Calis Jorg J. A. , Sanchez‐Perez Gabino F. , Keşmir Can 
Published: July 2010

AbstractDistinguishing self from nonself and pathogenic from nonpathogenic is a fundamental challenge to the immune system but whether adaptive immune systems use pathogen‐specific signatures to achieve this is largely unknown. By investigating the presentation of large sets of viruses and bacteria on MHC class I molecules, we analyze whether MHC‐I molecules have a preference for pathogen‐derived peptides. The fraction of potential MHC‐I binders in different organisms can vary up to eight‐fold. We find that this variation can be largely explained by G+C content differences of the organisms, which are reflected in amino acid frequencies. A significant majority of HLA‐A, but not HLA‐B, molecules has a preference for peptides derived from organisms with a low G+C content. Interestingly, a low G+C content seems to be a universal signature for pathogenicity. Finally, we find the same preferences in chimpanzee and rhesus macaque MHC‐I molecules. These results demonstrate that despite the fast evolution of MHC‐I alleles and their extreme polymorphism and diversity in peptide‐binding preferences, MHC‐I molecules can acquire a preference to exploit pathogen‐specific signatures.
Murine model of chronic L. (Viannia) panamensis infection: Role of IL‐13 in disease
Authors: Castilho Tiago M. , Goldsmith‐Pestana Karen , Lozano Caterin , Valderrama Liliana , Saravia Nancy G. , McMahon‐Pratt Diane 
Published: July 2010

AbstractLeishmania (Viannia) organisms are the most prevalent etiologic agents of human cutaneous leishmaniasis in the Americas. Nevertheless, our knowledge of the immunological mechanisms exploited by L. (Viannia) organisms remains limited and the mechanisms underlying disease are not well understood. Here, we report the development of a BALB/c mouse model of L. (V.) panamensis infection that is able to reproduce chronic disease, with persistent infection and clinically evident lesions for over 1 year. The immune response of the mouse resembles that found for L. (V.) panamensis‐infected patients with chronic and recurrent lesions, presenting a mixed Th1/Th2 response with the presence of TNF‐α, IFN‐γ, IL‐10 and IL‐13. Using immunodeficient mice, the critical role for IL‐13 and/or IL‐4Rα in determining susceptibility to chronic infection was evident. With the induction of healing in the immunodeficient mice, increases in IFN‐γ and IL‐17 were found, concomitant with parasite control and elimination. Specifically, increases in CD4+ (but not CD8+) T cells producing IFN‐γ were observed. These results suggest that IL‐13 represents an important target for disease control of L. (V.) panamensis infection. This murine model should be useful to further understand the pathology associated with chronic disease and to develop methods for the treatment and prevention of leishmaniasis caused by L. (Viannia) parasites.
Concomitant type I IFN receptor‐triggering of T cells and of DC is required to promote maximal modified vaccinia virus Ankara‐induced T‐cell expansion
Authors: Frenz Theresa , Waibler Zoe , Hofmann Janin , Hamdorf Matthias , Lantermann Markus , Reizis Boris , Tovey Michaël G. , Aichele Peter , Sutter Gerd , Kalinke Ulrich 
Published: July 2010

AbstractVirus‐induced expansion of CD8+ T cells may be promoted by type I IFN receptor (IFNAR)‐triggering of T cells, depending on the pathogen tested. We studied modified vaccinia virus Ankara (MVA), a promising vaccine vector candidate, which was derived from conventional vaccinia virus (VACV) by more than 570 consecutive in vitro passages. In adoptive transfer experiments, we verified that VACV expressing the gp33 epitope of lymphocytic choriomeningitis virus (VACVgp33) induced largely IFNAR‐independent expansion of gp33‐specific T cells. On the contrary, MVAgp33‐induced T‐cell expansion was IFNAR dependent. Interestingly, under the latter conditions, T‐cell activation was IFNAR independent, whereas T‐cell apoptosis was enhanced in the absence of IFNAR. To address whether MVA‐induced T‐cell expansion was solely affected by IFNAR‐triggering of T cells, expansion of endogenous T cells was studied in conditional mice with a T‐cell‐ or DC‐specific IFNAR deletion. Interestingly, both mouse strains showed moderately reduced T‐cell expansion, whereas mice with a combined T‐cell‐ and DC‐specific IFNAR ablation showed massively reduced T‐cell expansion similar to that of IFNAR−/− mice. These results are compatible with the model that IFN‐inducing viruses such as MVA confer virus‐specific CD8+ T‐cell expansion by concomitant IFNAR‐triggering of DC and of T cells.
Chemistry of 4‐Hydroxy‐2‐cyclopentenone Derivatives
Authors: Roche Stéphane P. , Aitken David J. 
Published: July 2010

AbstractThe 4‐hydroxy‐2‐cyclopentenone moiety is a highly valued molecular scaffold; it is bestowed with a wide‐ranging chemical reactivity profile which synthetic chemists have exploited increasingly over the last few decades. This review summarises the methods available for the preparation ofsimple building blocks which contain this core, then illustrates the diversity of chemical transformations which can be conducted with them, by highlighting applications in multi‐step syntheses of complex target molecules.
Influence of gusset plate connections and braces on the seismic performance of X‐braced frames
Authors: Roeder Charles W. , Lehman Dawn E. , Clark Kelly , Powell Jacob , Yoo Jung‐Han , Tsai Keh‐Chyuan , Lin Chih‐Han , Wei Chih‐Yu 
Published: July 2010

AbstractBraced frames are one of the most economical and efficient seismic resisting systems yet few full‐scale tests exist. A recent research project, funded by the National Science Foundation (NSF), seeks to fill this gap by developing high‐resolution data of improved seismic resisting braced frame systems. As part of this study, three full‐scale, two‐story concentrically braced frames in the multi‐story X‐braced configuration were tested. The experiments examined all levels of system performance, up to and including fracture of multiple braces in the frame. Although the past research suggests very limited ductility of SCBFs with HSS rectangular tubes for braces recent one‐story tests with improved gusset plate designs suggest otherwise. The frame designs used AISC SCBF standards and two of these frames designs also employed new concepts developed for gusset plate connection design. Two specimens employed HSS rectangular tubes for bracing, and the third specimen had wide flange braces. Two specimens had rectangular gusset plates and the third had tapered gusset plates. The HSS tubes achieved multiple cycles at maximum story drift ratios greater than 2% before brace fracture with the improved connection design methods. Frames with wide flange braces achieved multiple cycles at maximum story drift greater than 2.5% before brace fracture. Inelastic deformation was distributed between the two stories with the multi‐story X‐brace configuration and top story loading. Copyright © 2010 John Wiley & Sons, Ltd.
The geology of the area around Mynydd Mawr, Nantlle, Caernarvonshire
Authors: Cattermole P. , Jones A. 
Published: July 2010

AbstractStrata ranging from Arvonian to Llanvirnian are described. These rocks outcrop in a number of cylindrical or periclinal folds trending NE‐SW. The lowest rocks are voicanic and pass upwards into mainly coarse marine sedimentary rocks intercalated with thin turf bands and ignimbrites. These lowest Cambrian rocks must have been deposited in vcry shallow water while the ignimbrites would have been laid down on land. The slates of the Nantlle slate belt are overlain, in part conformably, by the Cymmffyrch (Bronllwyd) Grit of upper Lower Cambrian‐Middle Cambrian age, and this is overlain by thick Upper Cambrian slates and quartzites in the east of the area. No Arenig rocks are exposed as the Ffestiniog slates are immediately overlain by Llanvirnian.Two sets of folds are seen: the first (F1) phase includes mainly cylindrical or periclinal folds with steep limbs and an associated axial planar cleavage (S1) which are the basis of the regional structure. Later (F3) small‐scale folds produced flexure of the (F1) folds and associated with the later movements is an S3 crenulation cleavage. The riebeckite microgranite of Mynydd Mawr is briefly described.
APPLICATION OF GEOMEMBRANE TO CONTROL PIPING OF SANDY SOIL UNDER CONCRETE CANAL LINING (CASE STUDY: MOGHAN IRRIGATION PROJECT, IRAN)
Authors: Rahimi Hassan , Abbasi Nader , Shantia Hassan 
Published: July 2010

ABSTRACTFine sandy soils have always been known as one of those problematic soils which will erode rapidly and cause piping due to water flow. This phenomenon has caused the destruction of many concrete canal linings around the world. In the present study, the history of the design, construction and operation of a canal in the Moghan Irrigation and Drainage Network, in north‐west Iran, is reviewed and the main causes of destruction of the concrete lining of the canal are discussed. Based on the results of geotechnical studies, it was found that the canal was constructed on wind‐blown deposits consisting of very fine to fine sand and loess. During operation of the canal, the fine, clean sandy subgrade soil was highly eroded due to water seeping under the canal lining, causing severe piping and consequently destruction of the lining. Following field and laboratory investigations, the main cause of the problem was diagnosed as “physical dispersivity” of the subgrade soil, and application of a geomembrane under the concrete lining was chosen as the most economical and practical measure to remedy the problem. Copyright © 2010 John Wiley & Sons, Ltd.
Characterization of murine SIRT3 transcript variants and corresponding protein products
Authors: Yang Yongjie , Hubbard Basil P. , Sinclair David A. , Tong Qiang 
Published: July 2010

AbstractSIRT3 is one of the seven mammalian sirtuin homologs of the yeast SIR2 gene. SIRT3 possesses NAD+‐dependent protein deacetylase activity. Recent studies indicate that the murine SIRT3 gene expresses different transcript variants, resulting in three possible SIRT3 protein isoforms with various lengths at the N‐terminus: M1 (aa 1–334), M2 (aa 15–334), and M3 (aa 78–334). The transcript variants 1 and 3 can only produce M3 protein, while M1 and M2 proteins are translationally initiated from different in‐frame ATG sites in transcript 2. Here we report that three transcript variants of the mouse SIRT3 gene are broadly expressed in various mouse tissues. By expressing these SIRT3 isoforms in HEK293 cells through transient transfection, we confirmed recent reports that two longer murine SIRT3 proteins (M1 and M2) are targeted to mitochondria with higher efficiency than the shorter M3 isoform. Additionally, the M1 and M2 proteins are processed into a mature form. Using Edman degradation we identify Ile38 (majority) or Val42 as the N‐terminal amino acid of the mature M1 isoform, and Met78 or Val79 as the N‐terminal amino acid of the M3 isoform. Interestingly, we found that even upon mutation of the M2 ATG site in the M1 cDNA, a processed mature protein could still be produced. In terms of deacetylase activity, we found that although only the mature protein derived from M1 or M2 proteins were active against acetylated peptide substrates, all three forms had equal deacetylase activity towards a full‐length native protein substrate, acetyl CoA synthetase 2. J. Cell. Biochem. 111: 1051–1058, 2010. © 2010 Wiley‐Liss, Inc.
Sepsis downregulates myostatin mRNA levels without altering myostatin protein levels in skeletal muscle
Authors: Smith Ira J. , Aversa Zaira , Alamdari Nima , Petkova Victoria , Hasselgren Per‐Olof 
Published: July 2010

AbstractMyostatin is a negative regulator of muscle mass and has been reported to be upregulated in several conditions characterized by muscle atrophy. The influence of sepsis on myostatin expression and activity is poorly understood. Here, we tested the hypothesis that sepsis upregulates the expression and downstream signaling of myostatin in skeletal muscle. Because sepsis‐induced muscle wasting is at least in part regulated by glucocorticoids, we also determined the influence of glucocorticoids on myostatin expression. Sepsis was induced in rats by cecal ligation and puncture and control rats were sham‐operated. In other experiments, rats were injected intraperitoneally with dexamethasone (10 mg/kg) or corresponding volume of vehicle. Surprisingly, myostatin mRNA levels were reduced and myostatin protein levels were unchanged in muscles from septic rats. Muscle levels of activin A, follistatin, and total and phosphorylated Smad2 (p‐Smad2) were not influenced by sepsis, suggesting that myostatin downstream signaling was not altered during sepsis. Interestingly, total and p‐Smad3 levels were increased in septic muscle, possibly reflecting altered signaling through pathways other than myostatin. Similar to sepsis, treatment of rats with dexamethasone reduced myostatin mRNA levels and did not alter myostatin protein levels. Fasting, an additional condition characterized by muscle wasting, reduced myostatin mRNA and activin A protein levels, increased myostatin protein, and did not influence follistatin and p‐Smad2 levels. Of note, total and p‐Smad3 levels were reduced in muscle during fasting. The results suggest that sepsis and glucocorticoids do not upregulate the expression and activity of myostatin in skeletal muscle. The role of myostatin may vary between different conditions characterized by muscle wasting. Downstream signaling through Smad2 and 3 is probably regulated not only by myostatin but by other mechanisms as well. J. Cell. Biochem. 111: 1059–1073, 2010. © 2010 Wiley‐Liss, Inc.