bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional Gap Junctions Accumulate at the Immunological Synapse and Contribute to T Cell Activation
Authors: Mendoza-Naranjo Ariadna , Bouma Gerben , Pereda Cristián , Ramírez Marcos , Webb Kevin F. , Tittarelli Andrés , López Mercedes N. , Kalergis Alexis M. , Thrasher Adrian J. , Becker David L. , Salazar-Onfray Flavio 
Published: August 2011

Abstract
Gap junction (GJ) mediates intercellular communication through linked hemichannels from each of two adjacent cells. Using human and mouse models, we show that connexin 43 (Cx43), the main GJ protein in the immune system, was recruited to the immunological synapse during T cell priming as both GJs and stand-alone hemichannels. Cx43 accumulation at the synapse was Ag specific and time dependent, and required an intact actin cytoskeleton. Fluorescence recovery after photobleaching and Cx43-specific inhibitors were used to prove that intercellular communication between T cells and dendritic cells is bidirectional and specifically mediated by Cx43. Moreover, this intercellular cross talk contributed to T cell activation as silencing of Cx43 with an antisense or inhibition of GJ docking impaired intracellular Ca2+ responses and cytokine release by T cells. These findings identify Cx43 as an important functional component of the immunological synapse and reveal a crucial role for GJs and hemichannels as coordinators of the dendritic cell–T cell signaling machinery that regulates T cell activation.
Separation of Mutational and Transcriptional Enhancers in Ig Genes
Authors: Kothapalli Naga Rama , Collura Kaitlin M. , Norton Darrell D. , Fugmann Sebastian D. 
Published: August 2011

AbstractSecondary Ig gene diversification relies on activation-induced cytidine deaminase (AID) to create U:G mismatches that are subsequently fixed by mutagenic repair pathways. AID activity is focused to Ig loci by cis-regulatory DNA sequences named targeting elements. In this study, we show that in contrast to prevailing thought in the field, the targeting elements in the chicken IGL locus are distinct from classical transcriptional enhancers. These mutational enhancer elements (MEEs) are required over and above transcription to recruit AID-mediated mutagenesis to Ig loci. We identified a small 222-bp fragment in the chicken IGL locus that enhances mutagenesis without boosting transcription, and this sequence represents a key component of an MEE. Lastly, MEEs are evolutionarily conserved among birds, both in sequence and function, and contain several highly conserved sequence modules that are likely involved in recruiting trans-acting targeting factors. We propose that MEEs represent a novel class of cis-regulatory elements for which the function is to control genomic integrity.
Collections of extant cetaceans in Italian museums and other scientific institutions. A comparative review
Authors: Cagnolaro Luigi , Podestà Michela , Affronte Marco , Agnelli Paolo , Cancelli Fabrizio , Capanna Ernesto , Carlini Rossella , Cataldini Giorgio , Cozzi Bruno , Insacco Gianni , Maio Nicola , Marsili Letizia , Nicolosi Paola , Olivieri Vincenzo , Poggi Roberto , Renieri Tommaso , Wurtz Maurizio 
Published: August 2011

<div class="page" title="Page 1"><div class="layoutArea"><div class="column"><p><span style="font-size: 9pt; font-family: 'TimesNewRomanPSMT';">This paper summarizes more than four decades of cetacean research data collected by the Museo Civico di Storia Naturale di Milano and, between 1986 and 2003, by the Centro Studi Cetacei of the Società Italiana di Scienze Naturali. It is the result of the collaboration among scientists of several Italian museums. A detailed analysis concerning the amount and taxonomic representative</span><span style="font-size: 9pt; font-family: 'TimesNewRomanPSMT';">- </span><span style="font-size: 9pt; font-family: 'TimesNewRomanPSMT';">ness of the extant cetacean collections in Italian naturalistic museums and analogous institutions up until and including 2007 has been carried out. Adequately preserved and anatomically most significant specimens only have been taken into consideration. On the whole 1033 specimens representing 41 species are considered herein. They are housed in 53 institutions, of which the following ones hold the most important collections: the museums of Calci (Pisa), Genova, Firenze, Milano, Roma Zoology, </span><span style="font-size: 9pt; font-family: 'TimesNewRomanPSMT';">Siena, Comiso and Napoli. All the surveyed institutions are listed, with a short introduction about their material and an inven</span><span style="font-size: 9pt; font-family: 'TimesNewRomanPSMT';">- </span><span style="font-size: 9pt; font-family: 'TimesNewRomanPSMT';">tory of it. Specimens are then arranged in systematic order and some further data are provided in a table for each species. Such tables report the items of each museum with regard to quantity, preserva</span><span style="font-size: 9pt; font-family: 'TimesNewRomanPSMT';">- </span><span style="font-size: 9pt; font-family: 'TimesNewRomanPSMT';">tion techniques and, whenever possible, collecting data. Finally, a comparative analysis of the results is presented under multiple profiles: historical, preservation techniques, suitability of the specimens for research, place of origin, and the importance of the Italian cetacean collections for research and education. </span></p><p> </p></div></div></div>
The role of the Vlax Roma in shaping the European Romani maternal genetic history
Authors: Salihović Marijana Peričić , Barešić Ana , Klarić Irena Martinović , Cukrov Slavena , Lauc Lovorka Barać , Janićijević Branka 
Published: August 2011

AbstractThe Roma are comprised of many founder groups of common Indian origins but different socio‐cultural characteristics. The Vlax Roma are one of the founder Roma populations characterized by a period of bondage in the historic Romanian principalities, and by the archaic Romanian language. Demographic history suggests different migration routes of Roma populations, especially after their arrival in Mesopotamia and the eastern boundary of the Byzantine Empire. Although various genetic studies of uniparental genetic markers showed a connection between Roma genetic legacy and their migration routes, precise sampling of Roma populations elucidates this relationship in more detail. In this study, we analyzed mitochondrial DNA of 384 Croatian Vlax Roma from two geographic locations in the context of 734 European Roma samples. Our results show that Roma migration routes are marked with two Near‐Eastern haplogroups, X2 and U3, whose inverse proportional incidence clearly separates the Balkan and the Vlax Roma from other Roma populations that reached Europe as part of the first migration wave. Spatial and temporal characteristics of these haplogroups indicate a possibility of their admixture with Roma populations before arrival in Europe. Distribution of haplogroup M35 indicates that all Vlax Roma populations descend from one single founder population that might even reach back to the original ancestral Indian population. Founder effects followed by strict endogamy rules can be traced from India to contemporary small, local communities, as in the case of two Croatian Vlax Roma populations that show clear population differentiation despite similar origins and shared demographic history.Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Rheology of poly(vinyl chloride) plastisol for super‐high‐shear‐rate processing. II
Authors: Nakajima N. , Harrell E. R. 
Published: August 2011

AbstractCapillary flow of poly(vinyl chloride) plastisol was examined at low, high, and superhigh shear rates. At the low to intermediate shear rates, the flow was pseudo‐plastic, but the measured viscosity was not reproducible and widely scattered. The flow behavior was explained as the breakup of the particle network into network‐fragments of varying size. At high shear rates, the measured viscosity was reproducible and increased with shear rate, indicating that the particles were, by and large, separated from each other. At superhigh shear rates, the viscosity decreased with the increase of shear rate. The particles cease to participate in flow because rotation becomes more difficult. A plug‐flow ensues with a thin layer of lubricating plasticizer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Cationically cured natural oil‐based green composites: Effect of the natural oil and the agricultural fiber
Authors: Pfister Daniel P. , Larock Richard C. 
Published: August 2011

AbstractGreen composites were produced from various cationically cured natural oil‐based resins and agricultural fibers. The natural oils and agricultural fibers of interest included corn, soybean, fish, and linseed oils and corn stover, wheat straw (WS), and switchgrass fibers. The effects of the types of natural oil and agricultural fiber on the structure and thermal and mechanical properties of the composites were studied using Soxhlet extraction, thermogravimetric and dynamic mechanical analysis, and tensile testing. The green composites, with agricultural fiber loadings of 75 wt %, have thermal stabilities up to 275°C. The Young's moduli and tensile strengths of the composites ranged from 1590 to 2300 and 5.5 to 11.3 MPa, respectively. In general, an increase in the degree of unsaturation of the natural oil resulted in improvements in the thermal and mechanical properties of the composites. The WS fibers tended to give composites with the best thermal and mechanical properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Styrene–butadiene rubber membranes for the pervaporative separation of benzene/cyclohexane mixtures
Authors: Benguergoura Hassiba , Moulay Saad 
Published: August 2011

AbstractStyrene–butadiene rubber membranes with methylene bridges, stemming from the concomitant in situ Friedel–Crafts alkylation during a chloromethylation reaction, were prepared and used in the pervaporative separation of benzene/cyclohexane mixtures. A set of four membranes with different crosslinking extents was achieved by the variation of the [Trimethylchlorosilane (TMCS)]/[Paraformaldehyde (PF)] molar ratios with respect to the styrene (St) unit. Study of the swelling of membranes by the mixture components individually and by their feed mixture compositions, 1 : 1 and 1 : 9, was conducted. The total flux (J) and the separation factor (α) were assessed as a function of the feed composition, temperature, and [St unit]/[TMCS]/[PF] molar ratios. The highest J and α measured in this study were 1401 g m−2 h−1 and 28.50, respectively. The diffusion selectivity was found to depend on the crosslinking extent of the membrane. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis of polystyrene oligomers by nitroxide‐mediated radical polymerization using diethylketone triperoxide as a multifunctional radical initiator
Authors: de Anda Carlos , de los Santos Gladys , Morales Graciela 
Published: August 2011

AbstractStyrene oligomers (Mn, 2500–3000 g/mol) with low polydispersity index and containing peroxidic groups within their structure were synthesized using a novel trifunctional cyclic radical initiator, diethylketone triperoxide (DEKTP), through nitroxide‐mediated radical polymerization (NMRP), using OH‐TEMPO. During the synthesis of the polystyrene (PS) oligomers, camphorsulfonic acid (CSA) was used to inhibit the thermal autoinitiation of styrene at the evaluated temperatures (T = 120–130°C). The polymerization rate, which can be related to the slope of the plot of monomer conversion with reaction time, was monitored as a function of OH‐TEMPO, DEKTP, and CSA concentrations. The experimental results showed that all the synthesized polymers presented narrow molecular weight distributions, and the monomer conversion and the molecular weight of the polymers increased as a function of reaction time. Under the experimental conditions, T = 130°C, [DEKTP] = 10 mM, and [DEKTP]/[OH‐TEMPO] = 6.5, PS oligomers containing unreacted OO sites in their inner structure were obtained. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Influence of extrusion temperature on molecular architecture and crystallization behavior of peroxide‐induced slightly crosslinked poly(L‐lactide) by reactive extrusion
Authors: Takamura Masumi , Sugimoto Masataka , Kawaguchi Seigou , Takahashi Tatsuhiro , Koyama Kiyohito 
Published: August 2011

AbstractThe influence of temperature during reactive extrusion of poly(L‐lactide) (PLLA) on the molecular architecture and crystallization behavior was investigated for OO‐(t‐butyl) O‐(2‐ethylhexyl) peroxycarbonate‐modified polymer. The long chain–branched PLLA (LCB‐PLLA) content and its structure in the resulting slightly crosslinked PLLA (χ‐PLLA) containing linear and LCB‐PLLA were characterized by both analyses, size exclusion chromatography equipped with multiangle laser light scattering and rheological measurements. A reduction of LCB‐PLLA content in χ‐PLLA and an increase of number of branches in LCB‐PLLA were found with increasing the extrusion temperature. An increase of extrusion temperature induces different process in the polymer: decrease of the lifetime of peroxide, increase of the radical concentration due to rapid peroxide decomposition rate, and increase of the chain diffusion to the amorphous phase. Among these indices, the lifetime of peroxide is a good index for crosslinking behavior of PLLA during extrusion. As for the isothermal crystallization behavior from the melt, the Avrami crystallization rate constant of χ‐PLLA increases as an increase of LCB‐PLLA content in χ‐PLLA. This implies that LCB‐PLLA acts as a nucleating agent for PLLA. Furthermore, regime analysis and the free energy of nucleus of χ‐PLLA were investigated using Hoffman–Lauritzen theory. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Investigation and prediction on the nonlinear viscoelastic behaviors of nylon1212 toughened with elastomer
Authors: Wang Wanjie , Lu Zhanling , Cao Yanxia , Chen Jinzhou , Wang Jingwu , Zheng Qiang 
Published: August 2011

AbstractStudies on the nonlinear viscoelastic behaviors of nylon1212 toughened with styrene‐[ethylene‐(ethylene‐propylene)]‐styrene block copolymer (SEEPS) were carried out. The linear relaxation curves at relatively low shear strains show good overlap, the relaxation time and modulus corresponding to the characteristic relaxation modes were also acquired through simulating the linear relaxation modulus curves using Maxwell model. The nonlinear relaxation curves of nylon1212 blends at different shear strains have been obtained and their damping functions were evaluated. Meanwhile, it is found that most blends in the experimental windows follow the strain‐time separation principle and Laun double exponential model can predict damping curves well. The successive start‐up of shear behavior was investigated. The results showed that Wagner model, derived from the K‐BKZ (Kearsley‐Bernstein, Kearsley, Zapas) constitutive equation, could simulate the experiment data of nylon 1212 blend with 10 wt % SEEPS well, but there exists some deviation for experiment data of nylon1212 blends with high SEEPS concentrations. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The relationship between acquaintanceship and coauthorship in scientific collaboration networks
Authors: Pepe Alberto 
Published: August 2011

AbstractThis article examines the relationship between acquaintanceship and coauthorship patterns in a multi‐disciplinary, multi‐institutional, geographically distributed research center. Two social networks are constructed and compared: a network of coauthorship, representing how researchers write articles with one another, and a network of acquaintanceship, representing how those researchers know each other on a personal level, based on their responses to an online survey. Statistical analyses of the topology and community structure of these networks point to the importance of small‐scale, local, personal networks predicated upon acquaintanceship for accomplishing collaborative work in scientific communities.
Secondary Metabolites from Saussurea deltoidea and Their Inhibitory Activity on Lipopolysaccharide‐Induced Tumor Necrosis Factor Production
Authors: Tung Yu‐Lin , Cheng Ming‐Jen , Hu Nai‐Yun , Shih Ying‐Chu , Chiou Shu‐Jiau , Chen Ih‐Sheng 
Published: August 2011

AbstractBioassay‐guided fractionation of the whole plants of Saussurea deltoidea led to the isolation and structure elucidation of one new sesquiterpene, deltoidealactone (1), together with 23 known compounds 2–24. Their structures were established on the basis of extensive 1D‐ and 2D‐NMR analyses in combination with HR‐MS experiments. Deltoidealactone (1) inhibits tumor necrosis factor (TNF‐α) production in U937 cells in vitro with an IC50 value of 1.47 μg/ml.
Chemical Composition of the Leaf and Flower Essential Oils of Tunisian Lavandula dentata L. (Lamiaceae)
Authors: Touati Bechir , Chograni Hnia , Hassen Imed , Boussaïd Mohamed , Toumi Lamjed , Brahim Nadia Ben 
Published: August 2011

AbstractEssential oils of Lavandula dentata, a Tunisian native plant, were isolated from leaves and flowers by hydrodistillation in a Clevenger‐type apparatus and characterized by GC‐FID and GC/MS analyses. The average essential oil yields, means of five replicates, were higher for the flowers (8.60 mg/g) than for the leaves (6.56 mg/g). A total of 72 compounds were identified, accounting for 98.1 and 97.7% of the total oil composition of the leaves and flowers, respectively. The main essential oil constituents were 1,8‐cineole, camphor, and L‐fenchone, accounting for 33.54, 18.89, and 8.36% in the leaf oils and for 19.85, 23.33, and 7.13% in the flower oils, respectively. Besides this quantitative variation, the results also showed considerable qualitative variation between the essential oils of the two plant parts analyzed. These differences might be adaptative responses to ecological exigencies.
Multifunctional Polythreading Coordination Polymers: Spontaneous Resolution, Nonlinear‐Optic, and Ferroelectric Properties
Authors: Duan Xianying , Meng Qingjin , Su Yang , Li Yizhi , Duan Chunying , Ren Xiaoming , Lu Changsheng 
Published: August 2011

AbstractThe reactions of methylenediisophthalic acid (H4L) and N‐auxiliary ligands (1,2‐bis(4‐pyridyl)ethylene, 1,2‐bis(4‐pyridyl)ethane) with transition‐metal centers (Co2+/Mn2+) have given rise to four unprecedented polythreading coordination polymers. Single‐crystal X‐ray diffraction analyses revealed that the compounds can be described as 3D2−⊂2[1D2+]+2D6− for 1, 3D4−⊂1D2++1D6− for 2, and 2D4−⊂0D2++2[1D3−] for 3 and 4. All the polymers are formed through the assembly of two kinds of motifs with opposite charges. Noncentrosymmetric structures and multifunctionality in 2–4 are established by varying ligands and metal centers. Spontaneous resolution upon crystallization occurred in compounds 3 and 4 in the absence of any chiral source. The enantiomers of 3 and 4 consist of three chiral building blocks of L4−/HL3− and Mn2+ centers. In the solid state, polar compounds 2–4 exhibit nonlinear‐optic (NLO) and ferroelectric properties at room temperature. The assembly of two kinds of motifs with opposite charges provides a useful method for the preparation of multifunctional compounds.
Effects of terutroban, a thromboxane/prostaglandin endoperoxide receptor antagonist, on retinal vascularity in diabetic rats
Authors: De La Cruz J. P. , Jebrouni N. , López‐Villodres J. A. , Muñoz‐Marín J. , Guerrero A. , González‐Correa J. A. 
Published: August 2011

AbstractBackgroundThe aim of the present study is to investigate the effectiveness of terutroban, a selective antagonist of the thromboxane/prostaglandin endoperoxide receptor, in preventing retinal ischaemia in a model of diabetes in rats.MethodsExperimental diabetes was induced with streptozotocin. Rats were distributed into five groups (n = 20): (1) non‐diabetic rats, (2) rats with diabetes (DR) treated with vehicle, (3) DR treated with aspirin (2 mg/kg/day p.o.), (4) DR treated with terutroban (5 mg/kg/day p.o.), (5) DR treated with terutroban (30 mg/kg/day p.o.). The follow‐up period was 3 months. The main assessment was the percentage of retinal surface covered with vessels permeable to peroxidase. Platelet aggregation, aortic prostacyclin and nitric oxide production, plasma levels of lipid peroxides (thiobarbituric‐acid‐reactive substances) and 3‐nitrotyrosine and serum levels of IL‐6 were evaluated.ResultsDiabetes induced a reduction in retinal vascularity (76.9%), aortic prostacyclin (37.8%) and nitric oxide production (35.0%), and increased platelet aggregation, lipid peroxides, 3‐nitrotyrosine. When compared with vehicle‐treated DR, terutroban increased the percentage of retinal surface covered by PVPP (38% for terutroban‐5 and 61% for terutroban‐30), aortic prostacyclin (188% for terutroban‐5 and 146% for terutroban‐30) and nitric oxide production (320% for terutroban‐5 and 390% for terutroban‐30). Moreover, terutroban reduced platelet reactivity (27.8–95.1%, according to the inducer), lipid peroxides (60.7% for terutroban‐5 and 50.0% for terutroban‐30), 3‐nitrotyrosine (43.8% for terutroban‐5 and 36.8% for terutroban‐30) and IL‐6 concentration (18.0% for terutroban‐30). The effect of terutroban in retinal, nitrosative and aortic parameters was significantly higher than that of aspirin.ConclusionsTerutroban significantly protected retinal vascularity from ischaemia in experimental diabetes, and this result could be attributed not only to its antiplatelet/antithrombotic activities but also to its vascular properties. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of Optically Pure Diglycerol Tetraether Model Lipids with Non‐Natural Branching Pattern
Authors: Markowski Thomas , Drescher Simon , Meister Annette , Hause Gerd , Blume Alfred , Dobner Bodo 
Published: August 2011

AbstractThree new, chain‐modified, optically pure diglycerol tetraether lipids with one membrane‐spanning chain have been synthesised. These lipids contain a different number and constitution of the methyl branches connected to the hydrophobic chains as compared with natural archaeal or other previously synthesised lipids. The correct chirality of the branched alkyl chain was introduced starting from commercially available (S)‐citronellyl bromide. For chain elongation the Cu‐catalysed Grignard coupling reaction was used. Suitable blocked glycerol ethers were condensed to the tetraether moieties by Grubbs metathesis. The insertion of two or four optically pure methyl branches at the 10‐ and/or 23‐positions of the alkyl chains are sufficient to mimic the main properties of natural tetraether lipids. In this context, it has been shown that these lipids can form closed lipid vesicles.