bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly filled graphite polybenzoxazine composites for an application as bipolar plates in fuel cells
Authors: Dueramae Isala , Pengdam Anucha , Rimdusit Sarawut 
Published: July 2013

ABSTRACTHighly filled graphite polybenzoxazine composites as bipolar plate material for polymer electrolyte membrane fuel cell (PEMFC) are developed. At the maximum graphite content of 80 wt % (68 vol %), storage modulus was increased from 5.9 GPa of the neat polybenzoxazine matrix to 23 GPa in the composite. Glass transition temperatures (Tg) of the composites were ranging from 176°C to 195°C and the values substantially increased with increasing the graphite contents. Thermal conductivity as high as 10.2 W/mK and electrical conductivity of 245 S cm−1 were obtained in the graphite filled polybenzoxazine at its maximum graphite loading. The obtained properties of the graphite filled polybenzoxazine composites exhibit most values exceed the United States department of energy requirements for PEMFC applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3909–3918, 2013
Curcumin improves the therapeutic efficacy of Listeriaat‐Mage‐b vaccine in correlation with improved T‐cell responses in blood of a triple‐negative breast cancer model 4T1
Authors: Singh Manisha , Ramos Ilyssa , Asafu‐Adjei Denise , Quispe‐Tintaya Wilber , Chandra Dinesh , Jahangir Arthee , Zang Xingxing , Aggarwal Bharat B. , Gravekamp Claudia 
Published: July 2013

AbstractSuccess of cancer vaccination is strongly hampered by immune suppression in the tumor microenvironment (TME). Interleukin (IL)‐6 is particularly and highly produced by triple‐negative breast cancer (TNBC) cells, and has been considered as an important contributor to immune suppression in the TME. Therefore, we hypothesized that IL‐6 reduction may improve efficacy of vaccination against TNBC cancer through improved T‐cell responses. To prove this hypothesis, we investigated the effect of curcumin, an inhibitor of IL‐6 production, on vaccination of a highly attenuated Listeria monocytogenes (Listeriaat), encoding tumor‐associated antigens (TAA) Mage‐b in a TNBC model 4T1. Two therapeutic vaccination strategies with Listeriaat‐Mage‐b and curcumin were tested. The first immunization strategy involved all Listeriaat‐Mage‐b vaccinations and curcumin after tumor development. As curcumin has been consumed all over the world, the second immunization strategy involved curcumin before and all therapeutic vaccinations with Listeriaat‐Mage‐b after tumor development. Here, we demonstrate that curcumin significantly improves therapeutic efficacy of Listeriaat‐Mage‐b with both immunization strategies particularly against metastases in a TNBC model (4T1). The combination therapy was slightly but significantly more effective against the metastases when curcumin was administered before compared to after tumor development. With curcumin before tumor development in the combination therapy, the production of IL‐6 was significantly decreased and IL‐12 increased by myeloid‐derived suppressor cells (MDSC), in correlation with improved CD4 and CD8 T‐cell responses in blood. Our study suggests that curcumin improves the efficacy of Listeriaat‐Mage‐b vaccine against metastases in TNBC model 4T1 through reversal of tumor‐induced immune suppression.
Social Networking Sites: Mediating the Self and its Communities
Authors: Whittaker Lisa , Gillespie Alex 
Published: July 2013

ABSTRACTWhat do social networking sites reveal about the relation between the self and the community? We conceptualise social networking sites as technologies of the self and the community enabling individuals to self‐present and also objectifying the community's evaluation of individuals (through ‘structures of recognition’ such as page views, friends and lovehearts). We analyse the way in which 37 Scottish adolescents used the social networking site Bebo in nonprescribed and creative ways. First, they challenged the single authorship of profiles by co‐creating multi‐authored profiles. Second, they used creative language to obscure meaning from the preying eyes of parents, teachers and potential employers. We conclude by discussing the simplistic assumptions that Bebo makes about the relation between the self and the community. In contrast, newer social networking sites such as Facebook and Google+ are increasingly enabling people to present different facets of themselves to different communities. How people use social networking sites, and how these sites are developing to attract more users, reveals how the multiplicity of human identity is related to the multiple communities that people participate in. Copyright © 2013 John Wiley & Sons, Ltd.
Formation Kinetics and Structural Features of Beta‐Amyloid Aggregates by Sedimented Solute NMR
Authors: Bertini Ivano , Gallo Gianluca , Korsak Magdalena , Luchinat Claudio , Mao Jiafei , Ravera Enrico 
Published: July 2013

AbstractThe accumulation of soluble toxic beta‐amyloid (Aβ) aggregates is an attractive hypothesis for the role of this peptide in the pathology of Alzheimer's disease. We have introduced sedimentation through ultracentrifugation, either by magic angle spinning (in situ) or preparative ultracentrifuge (ex situ), to immobilize biomolecules and make them amenable for solid‐state NMR studies (SedNMR). In situ SedNMR is used here to address the kinetics of formation of soluble Aβ assemblies by monitoring the disappearance of the monomer and the appearance of the oligomers simultaneously. Ex situ SedNMR allows us to select different oligomeric species and to reveal atomic‐level structural features of soluble Aβ assemblies.
Microstructure of Bimetallic PtPd Catalysts under Oxidizing Conditions
Authors: Johns Tyne R. , Gaudet Jason R. , Peterson Eric J. , Miller Jeffrey T. , Stach Eric A. , Kim Chang H. , Balogh Michael P. , Datye Abhaya K. 
Published: July 2013

AbstractDiesel oxidation catalysts (DOCs), which decrease the amount of harmful carbon monoxide (CO), nitrogen oxide (NO), and hydrocarbon (HC) emissions in engine exhaust, typically utilize Pt and Pd in the active phase. There is universal agreement that the addition of Pd improves both the catalytic performance and the durability of Pt catalysts. However, the mechanisms by which Pd improves the performance of Pt are less clear. Because these catalysts operate under oxidizing conditions, it is important to understand these catalysts in their working state. Herein, we report the microstructure of PtPd catalysts that are aged in air at 750 °C. After 10 h of aging, EXAFS and XANES analysis show that the Pt is fully reduced but that almost 30 % of the Pd species are present as an oxide. HRTEM images show no evidence of surface oxides on the metallic PtPd particles. Instead, the PdO is present as a separate phase that is dispersed over the alumina support. Within the metallic particles, Pt and Pd are uniformly distributed and there is no evidence of core–shell structures. Therefore, the improved catalytic performance is likely associated with the co‐existence of metallic Pt and Pd on the catalyst surface.
Photoswitchable Hydrogel Surface Topographies by Polymerisation‐Induced Diffusion
Authors: Stumpel Jelle E. , Liu Danqing , Broer Dirk J. , Schenning Albertus P. H. J. 
Published: July 2013

AbstractHerein, we describe the preparation of patterned photoresponsive hydrogels by using a facile method. This polymer‐network hydrogel coating consists of N‐isopropylacrylamide (NIPAAM), cross‐linking agent tripropylene glycol diacrylate (TPGDA), and a new photochromic spiropyran monoacrylate. In a pre‐study, a linear NIPAAM copolymer (without TPGDA) that contained the spiropyran dye was synthesised, which showed relatively fast photoswitching behaviour. Subsequently, the photopolymerisation of a similar monomer mixture that included TPGDA afforded freestanding hydrogel polymer networks. The light‐induced isomerisation of protonated merocyanine into neutral spiropyran under slightly acidic conditions resulted in macroscopic changes in the hydrophilicity of the entire polymer film, that is, shrinkage of the hydrogel. The degree of shrinkage could be controlled by changing the chemical composition of the acrylate mixture. After these pre‐studies, a hydrogel film with spatially modulated cross‐link density was fabricated through polymerisation‐induced diffusion, by using a patterned photomask. The resulting smooth patterned hydrogel coating swelled in slightly acidic media and the swelling was higher in the regions with lower cross‐linking densities, thus yielding a corrugated surface. Upon exposure to visible light, the surface topography flattened again, thus showing that a hydrogel coating could be created, the topography of which could be controlled by light irradiation.
Molecular‐Level Insights into the Oxidative Degradation of Grafted Amines
Authors: Ahmadalinezhad Asieh , Tailor Ritesh , Sayari Abdelhamid 
Published: July 2013

AbstractThe oxidative degradation of CO2 adsorbents consisting of amine‐grafted pore‐expanded mesoporous MCM‐41 silica was investigated. The adsorbents were treated under flowing air at various temperatures, and the degree of deactivation was evaluated through the measurement of their CO2 adsorption capacity prior and subsequent to exposure to air. To decipher the chemical structure of surface species upon air‐deactivation of grafted amines, a solvent extraction procedure was developed using a deuterated basic solution. The obtained solutions were analyzed by a variety of 1D and 2D NMR spectroscopy techniques, such as 29Si, 13C, 1H, [1H,15N] HMBC, [1H,13C] HMQC, COSY and DOSY. The surface species generated by oxidative degradation of amine‐grafted silica were found to contain functional groups such as imine, amide and carboxylic groups. Several structural units were conclusively demonstrated.
The Ligand‐Based Quintuple Bond‐Shortening Concept and Some of Its Limitations
Authors: Noor Awal , Bauer Tobias , Todorova Tanya K. , Weber Birgit , Gagliardi Laura , Kempe Rhett 
Published: July 2013

AbstractHerein, the ligand‐based concept of shortening quintuple bonds and some of its limitations are reported. In dichromium–diguanidinato complexes, the length of the quintuple bond can be influenced by the substituent at the central carbon atom of the used ligand. The guanidinato ligand with a 2,6‐dimethylpiperidine backbone was found to be the optimal ligand. The reduction of its chromium(II) chloride–ate complex gave a quintuply bonded bimetallic complex with a CrCr distance of 1.7056 (12) Å. Its metal–metal distance, the shortest observed in any stable compound yet, is of essentially the same length as that of the longest alkane CC bond (1.704 (4) Å). Both molecules, the alkane and the Cr complex, are of remarkable stability. Furthermore, an unsupported CrI dimer with an effective bond order (EBO) of 1.25 between the two metal atoms, indicated by CASSCF/CASPT2 calculations, was isolated as a by‐product. The formation of this by‐product indicates that with a certain bulk of the guanidinato ligand, other coordination isomers become relevant. Over‐reduction takes place, and a chromium–arene sandwich complex structurally related to the classic dibenzene chromium complex was observed, even when bulkier substituents are introduced at the central carbon atom of the used guanidinato ligand.
Mechanistic Study on the Cleavage and Reorganization of C(sp3)H and CN Bonds in Carbodiimides: Synthesis of 1,2‐Dihydrothiopyrimidines and 2,3‐Dihydropyrimidinthiones through Four‐Component Coupling
Authors: Wang Yang , Zhao Fei , Zhou Yi , Chi Yue , Wang Zitao , Zhang Wen‐Xiong , Xi Zhenfeng 
Published: July 2013

AbstractThis study sheds light on the cleavage and reorganization of C(sp3)H and CN bonds of carbodiimides in a three‐component reaction of terminal alkynes, sulfur, and carbodiimides by a combination of methods including 1) isolation and X‐ray analysis of six‐membered‐ring lithium species 2‐S, 2) trapping of the oxygen‐analogues (B‐O and D‐O) of both four‐membered‐ring intermediate B‐S and ring‐opening intermediate D‐S, 3) deuterium labeling studies, and 4) theoretical studies. These results show that 1) the reaction rate‐determining step is [2+2] cycloaddition, 2) the CN bond cleavage takes place before C(sp3)H bond cleavage, 3) the hydrogen attached to C6 in 2‐S originates from the carbodiimide, and 4) three types of new aza‐heterocycles, such as 1,2‐dihydrothiopyrimidines, N‐acyl 2,3‐dihydropyrimidinthiones, and 1,2‐dihydropyrimidinamino acids are constructed efficiently based on 2‐S. All results strongly support the idea that the reaction proceeds through [2+2] cycloaddition/4π electrocyclic ring‐opening/1,5‐H shift/6π electrocyclic ring‐closing as key steps. The research strategy on the synthesis, isolation, and reactivity investigation of important intermediates in metal‐mediated reactions not only helps achieve an in‐depth understanding of reaction mechanisms but also leads to the discovery of new synthetically useful reactions based on the important intermediates.
Empirical likelihood confidence regions for the evaluation of continuous‐scale diagnostic tests in the presence of verification bias
Authors: Wang Binhuan , Qin Gengsheng 
Published: July 2013

AbstractIn a continuous‐scale diagnostic test, when a cut‐off level is given, the performance of the test in distinguishing diseased subjects from non‐diseased subjects can be evaluated by its sensitivity and specificity. Joint inferences for sensitivity and specificity as well as cut‐off level play an important role in the assessment of the diagnostic accuracy of the test. Most current studies on this topic focus on complete data cases. However, in some studies, only a portion of subjects given their screening test results ultimately have their true disease status verified. In addition, the verification may depend on the test result and the subject's observed characteristics. Directly applying full data methods to verified subjects results in biased estimates, known as verification bias. In this paper, based on a general framework that combines empirical likelihood and general estimation equations with nuisance parameters, we propose various bias‐corrected joint empirical likelihood confidence regions for sensitivity and specificity with verification‐biased data. Thorough simulation studies are conducted to compare the finite sample performance of the proposed confidence regions in terms of coverage probabilities, and some suggestions are provided accordingly. Finally, an example is provided to illustrate the proposed methods.The Canadian Journal of Statistics41: 398–420; 2013 © 2013 Statistical Society of Canada
Adsorption of Fluoride on the Raw and Modified Cement Clay
Authors: Atasoy Ayse Dilek , Sahin Muge Ozdemir 
Published: July 2013

AbsctractAdsorption of fluoride (F) on the raw and modified local cement clay was investigated by batch method. Modified clays were prepared through calcination, using the Na and Mg saturated (C‐Na, C‐Mg) clay at 500 and 850°C (C‐500, C‐850) and calcination of Mg incorporated clay at 500°C (C‐Mg‐500). The equilibration time was attained in 5 h. Adsorption of F increased with increasing adsorbent dose. Decrease of the initial F concentration resulted in an increasing amount of F adsorption. F adsorption isotherms fitted well with both Freundlich and Langmuir models. Low F adsorption was obtained on the raw, incorporated or calcined clays. However maximum F adsorption was found for C‐Mg‐500, with Kf and Q0 values of 0.27 and 1.69, respectively. This work indicated that the calcination of incorporated clay with Mg increased the F adsorption significantly, due to increased and stabilized positive sites.
Recurrent glioblastoma: Volumetric assessment and stratification of patient survival with early posttreatment magnetic resonance imaging in patients treated with bevacizumab
Authors: Huang Raymond Y. , Rahman Rifaquat , Hamdan Alhafidz , Kane Caroline , Chen Christina , Norden Andrew D. , Reardon David A. , Mukundun Srinivasan , Wen Patrick Y. 
Published: July 2013

BACKGROUNDDespite a high radiographic response rate in patients with recurrent glioblastoma following bevacizumab therapy, survival benefit has been relatively modest. We assess whether tumor volume measurements based on baseline and early posttreatment MRI can stratify patients in terms of progression‐free survival (PFS) and overall survival (OS).METHODSBaseline (−4 +/‐ 4 days) and posttreatment (30 +/‐ 6 days) MRI exams of 91 patients with recurrent glioblastoma treated with bevacizumab were retrospectively evaluated for volume of enhancing tumor as well as volume of the T2/FLAIR hyperintensity. Overall survival (OS) and progression‐free survival (PFS) were assessed using volume parameters in a Cox regression model adjusted for significant clinical parameters.RESULTSIn univariable analysis, residual tumor volume, percentage change in tumor volume, steroid change from baseline to posttreatment scan, and number of recurrences were associated with both OS and PFS. With dichotomization by sample median of 52% change of enhancing volume can stratify OS (52 weeks vs. 31 weeks, P = .013) and PFS (21 weeks vs. 12 weeks, P = .009). Residual enhancing volume, dichotomized by sample median of 7.8 cm3, can also stratify for OS (64 weeks vs. 28 weeks, P < .001) and PFS (21 weeks vs. 12 weeks, P = .036).CONCLUSIONSVolumetric percentage change and absolute early posttreatment volume of enhancing tumor can stratify survival for patients with recurrent glioblastoma receiving bevacizumab therapy. Cancer 2013;119:3479–3488.. © 2013 American Cancer Society.
The impact of gene expression analysis on evolving views of avian brain organization
Authors: Montiel Juan F. , Molnár Zoltán 
Published: July 2013

ABSTRACTRecent studies have presented data on adult and developing avian brain organization. Jarvis et al. ([2013] J Comp Neurol. 521:3614–3665) identify four pallial and two subpallial gene expression domains and demonstrate that the mesopallium and adjoining divisions of the hyperpallium (hyperpallium intercalatum and hyperpallium densocellulare), have very similar gene expression profiles to each other, distinct from those of the nidopallium, the arcopallium, and the more distant divisions of the hyperpallium (hyperpallium apicale). The study proposes an update of the current nomenclature (Jarvis et al. [2005] Nat Rev Neurosci. 6:151–159). The authors perform densitometric quantifications of the in situ expression of 50 selected genes, use correlations of distances between vectors that represent these gene expression patterns within the 23 avian brain regions of their study, and group them according to similarity in their expression profiles. The generated cluster tree further supports their argument for a new terminology. The authors hypothesize that the mesopallium and adjoining divisions of the hyperpallium have a common developmental origin, and in the accompanying paper (Chen et al. [2013] J Comp Neurol. 521:3666–3701) show that these structures/subdivisions initially form continuous gene expression domains. With subsequent development these domains fold into distinct subdivisions in the dorsal and ventral avian pallium, forming mirror images to each other. Jarvis et al. ([2013] J Comp Neurol. 521:3614–3665) also demonstrate interesting principles of the functional organization of the avian brain by showing that specific sensory stimulation or motor behavior elicits gene expression in functional units perpendicular to the axis of the gene expression reversal and compare their arrangements and cell types with mammalian cortical columns. J. Comp. Neurol. 521:3604–3613, 2013. © 2013 Wiley Periodicals, Inc.
Global view of the functional molecular organization of the avian cerebrum: Mirror images and functional columns
Authors: Jarvis Erich D. , Yu Jing , Rivas Miriam V. , Horita Haruhito , Feenders Gesa , Whitney Osceola , Jarvis Syrus C. , Jarvis Electra R. , Kubikova Lubica , Puck Ana E.P. , Siang‐Bakshi Connie , Martin Suzanne , McElroy Michael , Hara Erina , Howard Jason , Pfenning Andreas , Mouritsen Henrik , Chen Chun‐Chun , Wada Kazuhiro 
Published: July 2013

ABSTRACTBased on quantitative cluster analyses of 52 constitutively expressed or behaviorally regulated genes in 23 brain regions, we present a global view of telencephalic organization of birds. The patterns of constitutively expressed genes revealed a partial mirror image organization of three major cell populations that wrap above, around, and below the ventricle and adjacent lamina through the mesopallium. The patterns of behaviorally regulated genes revealed functional columns of activation across boundaries of these cell populations, reminiscent of columns through layers of the mammalian cortex. The avian functionally regulated columns were of two types: those above the ventricle and associated mesopallial lamina, formed by our revised dorsal mesopallium, hyperpallium, and intercalated hyperpallium; and those below the ventricle, formed by our revised ventral mesopallium, nidopallium, and intercalated nidopallium. Based on these findings and known connectivity, we propose that the avian pallium has four major cell populations similar to those in mammalian cortex and some parts of the amygdala: 1) a primary sensory input population (intercalated pallium); 2) a secondary intrapallial population (nidopallium/hyperpallium); 3) a tertiary intrapallial population (mesopallium); and 4) a quaternary output population (the arcopallium). Each population contributes portions to columns that control different sensory or motor systems. We suggest that this organization of cell groups forms by expansion of contiguous developmental cell domains that wrap around the lateral ventricle and its extension through the middle of the mesopallium. We believe that the position of the lateral ventricle and its associated mesopallium lamina has resulted in a conceptual barrier to recognizing related cell groups across its border, thereby confounding our understanding of homologies with mammals. J. Comp. Neurol. 521:3614–3665, 2013. © 2013 Wiley Periodicals, Inc.
Splicing factor TRA2B is required for neural progenitor survival
Authors: Roberts Jacqueline M. , Ennajdaoui Hanane , Edmondson Carina , Wirth Brunhilde , Sanford Jeremy R. , Chen Bin 
Published: July 2013

ABSTRACTAlternative splicing of pre‐mRNAs can rapidly regulate the expression of large groups of proteins. The RNA binding protein TRA2B (SFRS10) plays well‐established roles in developmentally regulated alternative splicing during Drosophila sexual differentiation. TRA2B is also essential for mammalian embryogenesis and is implicated in numerous human diseases. Precise regulation of alternative splicing is critical to the development and function of the central nervous system; however, the requirements for specific splicing factors in neurogenesis are poorly understood. This study focuses on the role of TRA2B in mammalian brain development. We show that, during murine cortical neurogenesis, TRA2B is expressed in both neural progenitors and cortical projection neurons. Using cortex‐specific Tra2b mutant mice, we show that TRA2B depletion results in apoptosis of the neural progenitor cells as well as disorganization of the cortical plate. Thus, TRA2B is essential for proper development of the cerebral cortex. J. Comp. Neurol. 522:372–392, 2014. © 2013 Wiley Periodicals, Inc.