bluuebunny/crossref_metadata_2025_split huggingface dataset:
TGF-β–Exposed Plasmacytoid Dendritic Cells Participate in Th17 Commitment
Authors: Bonnefoy Francis , Couturier Mélanie , Clauzon Amandine , Rémy-Martin Jean-Paul , Gaugler Béatrice , Tiberghien Pierre , Chen Wanjun , Saas Philippe , Perruche Sylvain 
Published: April 2011

Abstract
TGF-β is required for both Foxp3+ regulatory T cell (Treg) and Th17 commitment. Plasmacytoid DCs (pDC) have been shown to participate to both Treg and Th17 commitment as well. However, few studies have evaluated the direct effect of TGF-β on pDC, and to our knowledge, no study has assessed the capacity of TGF-β–exposed pDC to polarize naive CD4+ T cells. In this paper, we show that TGF-β–treated pDC favor Th17 but not Treg commitment. This process involves a TGF-β/Smad signal, because TGF-β treatment induced Smad2 phosphorylation in pDC and blockade of TGF-β signaling with the SD208 TGF-βRI kinase inhibitor abrogated Th17 commitment induced by TGF-β–treated pDC. Moreover, TGF-β mRNA synthesis and active TGF-β release were induced in TGF-β–treated pDC and anti–TGF-β Ab blocked Th17 commitment. Unexpectedly, TGF-β treatment also induced increased IL-6 production by pDC, which serves as the other arm for Th17 commitment driven by TGF-β–exposed pDC, because elimination of IL-6–mediated signal with either IL-6– or IL-6Rα–specific Abs prevented Th17 commitment. The in vivo pathogenic role of TGF-β–treated pDC was further confirmed in the Th17-dependent collagen-induced arthritis model in which TGF-β–treated pDC injection significantly increased arthritis severity and pathogenic Th17 cell accumulation in the draining lymph nodes. Thus, our data reveal a previously unrecognized effect of TGF-β–rich environment on pDC ability to trigger Th17 commitment. Such findings have implications in the pathogenesis of autoimmune diseases or immune responses against mucosal extracellular pathogens.
Macrophage Migration Inhibitory Factor: A Downregulator of Early T Cell-Dependent IFN-γ Responses in Plasmodium chabaudi adami (556 KA)-Infected Mice
Authors: Malu Diane Tshikudi , Bélanger Benoit , Desautels François , Kelendji Karine , Dalko Esther , Sanchez-Dardon Jaime , Leng Lin , Bucala Richard , Satoskar Abhay R. , Scorza Tatiana 
Published: April 2011

Abstract
Neutralization of macrophage migration inhibitory factor (MIF) increases anti-tumor cytotoxic T cell responses in vivo and IFN-γ responses in vitro, suggesting a plausible regulatory role for MIF in T cell activation. Considering that IFN-γ production by CD4+ T cells is pivotal to resolve murine malaria and that secretion of MIF is induced by Plasmodium chabaudi adami parasites, we investigated the effect of MIF deficiency on the infection with this pathogen. Infections with P. c. adami 556 KA parasites were more efficiently controlled in MIF-neutralized and MIF-deficient (knockout [KO]) BALB/c mice. The reduction in parasitemia was associated with reduced production of IL-4 by non-T/non-B cells throughout patent infection. At day 4 postinfection, higher numbers of activated CD4+ cells were measured in MIF KO mice, which secreted more IFN-γ, less IL-4, and less IL-10 than did CD4+ T cells from wild-type mice. Enhanced IFN-γ and decreased IL-4 responses also were measured in MIF KO CD4+ T cells stimulated with or without IL-12 and anti–IL-4 blocking Ab to induce Th1 polarization. However, MIF KO CD4+ T cells efficiently acquired a Th2 phenotype when stimulated in the presence of IL-4 and anti–IL-12 Ab, indicating normal responsiveness to IL-4/STAT6 signaling. These results suggest that by promoting IL-4 responses in cells other than T/B cells during early P. c. adami infection, MIF decreases IFN-γ secretion in CD4+ T cells and, additionally, has the intrinsic ability to render CD4+ T cells less capable of acquiring a robust Th1 phenotype when stimulated in the presence of IL-12.
The C-Terminally Encoded, MHC Class II-Restricted T Cell Antigenicity of the Helicobacter pylori Virulence Factor CagA Promotes Gastric Preneoplasia
Authors: Arnold Isabelle C. , Hitzler Iris , Engler Daniela , Oertli Mathias , Agger Else Marie , Müller Anne 
Published: April 2011

Abstract
Chronic infection with the human bacterial pathogen Helicobacter pylori causes gastritis and predisposes carriers to an increased gastric cancer risk. Consequently, H. pylori-specific vaccination is widely viewed as a promising strategy of gastric cancer prevention. H. pylori strains harboring the Cag pathogenicity island (PAI) are associated with particularly unfavorable disease outcomes in humans and experimental rodent models. We show in this study using a C57BL/6 mouse model of Cag-PAI+ H. pylori infection that the only known protein substrate of the Cag-PAI–encoded type IV secretion system, the cytotoxin-associated gene A (CagA) protein, harbors MHC class II-restricted T cell epitopes. Several distinct nonoverlapping epitopes in CagA’s central and C-terminal regions were predicted in silico and could be confirmed experimentally. CagA+ infection elicits CD4+ T cell responses in mice, which are strongly enhanced by prior mucosal or parenteral vaccination with recombinant CagA. The adoptive transfer of CagA-specific T cells to T cell-deficient, H. pylori-infected recipients is sufficient to induce the full range of preneoplastic immunopathology. Similarly, immunization with a cholera toxin-adjuvanted, CagA+ whole-cell sonicate vaccine sensitizes mice to, rather than protects them from, H. pylori-associated gastric cancer precursor lesions. In contrast, H. pylori-specific tolerization by neonatal administration of H. pylori sonicate in conjunction with a CD40L-neutralizing Ab prevents H. pylori-specific, pathogenic T cell responses and gastric immunopathology. We conclude that active tolerization may be superior to vaccination strategies in gastric cancer prevention.
Modeling the effects of weaning age on length of female reproductive period: Implications for the evolution of human life history
Authors: Kachel A. Friederike , Premo L.S. , Hublin Jean‐Jacques 
Published: April 2011

AbstractObjectives:Human life history is unique among primates. Despite our extended lifespan, the length of the female reproductive period is shorter in humans than in our closest living relatives, chimpanzees. Here, we investigate whether this difference could be explained by another unique aspect of human life history—a young weaning age.Methods:Age‐dependent female fertility is modeled with the Brass polynomial. We model female reproductive period length as single locus with multiple alleles. Selection acts on the length of the female reproductive period in an evolutionary agent‐based simulation. We quantify the effect of weaning age on the optimal length of the female reproductive period under a range of adult mortality rates.Results:Females sacrifice a smaller proportion of their reproductive potential due to nursing by weaning their offspring at younger ages. As a consequence, the optimal length of the female reproductive period decreases as weaning age decreases, even when adult mortality is low.Conclusions:Natural selection will favor mutations or strategies that can decrease weaning age without incurring fitness costs. In the presence of younger weaning ages, selection favors a shorter female reproductive period. To the extent that allocare can decrease weaning age without decreasing fitness, its ubiquity in human societies and near absence in other primate societies may explain why women have a shorter reproductive period. Furthermore, allocare may have provided human ancestors with an avenue to decreased weaning age—and, ultimately, a shorter female reproductive period—that was unavailable to their hominoid contemporaries. Am. J. Hum. Biol. 2011. © 2011Wiley‐Liss, Inc.
Caregiving, gender, and nutritional status in Nyanza Province, Kenya: Grandmothers gain, grandfathers lose
Authors: Ice Gillian H. , Heh Victor , Yogo Jaja , Juma Elizabeth 
Published: April 2011

AbstractBased on anecdotal and qualitative reports, a general assumption is that caregiving negatively impacts grandparents in Africa.Objectives:The purpose of this article is to determine how caregiving and gender impact nutritional status over four waves of data from Luo elders.Methods:Luo elders, aged 60 and over (age 73.6 ± 7.9) were sampled. Participant recruitment was rolling and included 287 Luo grandparents in 2005, 396 in 2006, 389 in 2007, and 390 in 2009. A total of 689 elders participated in at least 1 year. Standard anthropometric measures were used to determine nutritional status. Impact of caregiving was examined using structural equation models.Results:Caregiving positively associated with nutritional status among women. This main effect was mediated by caregiving intensity, which also positively associated with nutritional status. Among men, caregiving negatively associated with nutritional status, although caregiving intensity did not significantly associate with most anthropometric measures. Socioeconomic status (SES) positively associated with five of nine anthropometric measures in women and all measures in men. Several measures indicated that both men and women became larger over time but few of the variables tested predicted growth.Conclusions:The beneficial impact on grandmothers might indicate a coping strategy. These results indicated that researchers should shift away from comparing caregivers to noncaregivers and instead look at the multiple factors which may make some families resilient and others at risk. Human biologists can contribute to this literature by examining the ecological and cultural contexts under which caregiving represents a burden with physiological repercussions. Am. J. Hum. Biol. 2011. © 2011Wiley‐Liss, Inc.
Bilden und Brechen von Peptidbindungen: Protein‐Engineering mithilfe von Sortase
Authors: Popp Maximilian Wei‐Lin , Ploegh Hidde L. 
Published: April 2011

AbstractSortasen gehören zu einer Klasse bakterieller Enzyme, die Transpeptidaseaktivität aufweisen. Die Fähigkeit, Peptidbindungen ortsspezifisch zu brechen und neue Bindungen mit einem angreifenden Nukleophil zu bilden, macht Sortase zu einem hervorragenden Hilfsmittel für das Protein‐Engineering. Diese Methode wurde für eine Reihe von Anwendungen angepasst, die von der Chemie über die Zellbiologie bis hin zu technischen Gebieten reichen. Wir wollen hier einen kurzen Überblick über die Biologie der Sortaseenzyme und ihre Anwendungen im Protein‐Engineering geben, auf Gebiete für zukünftige Innovationen hinweisen und neue Anwendungen vorschlagen.
Cp2ZrCl2‐induced Reformatsky and Barbier reactions on isatins: an efficient synthesis of 3‐substituted‐3‐hydroxyindolin‐2‐ones
Authors: Chouhan Mangilal , Sharma Ratnesh , Nair Vipin A. 
Published: April 2011

AbstractA mild and rapid one‐pot process for Reformatsky and Barbier reactions using a catalytic quantity of zirconocene dichloride (Cp2ZrCl2) as a promoter and zinc as a terminal reductant at room temperature in dimethyl formamide was developed. The protocol has wide substrate suitability and afforded the desired 3‐substituted‐3‐hydroxyindolin‐2‐ones from istains in good yields and short reaction time. Copyright © 2011 John Wiley & Sons, Ltd.
A Suzuki‐type cross‐coupling reaction of arylacetylene halides with arylboronic acids
Authors: Shi Yu , Li Xiaoyu , Liu Jianhui , Jiang Wenfeng , Sun Licheng 
Published: April 2011

AbstractA PdCl2‐catalyzed direct alkynylation of arylboronic acids to give diarylacetylenes is described. The optimal conditions using PdCl2 as catalyst, MeOHPhMeH2O as solvent and K2CO3 as base effectively suppressed the formation of homo‐coupling product and afforded moderate to good yield of the desired unsymmetrical coupling product. This reaction represents a Suzuki‐type sp2(CB)–sp(CX) cross‐coupling. Copyright © 2011 John Wiley & Sons, Ltd.
Polyacrylamide‐grafted carboxymethyl cellulose: Smart pH‐sensitive hydrogel for protein concentration
Authors: Eldin M. S. Mohy , El‐Sherif H. M. , Soliman E. A. , Elzatahry A. A. , Omer A. M. 
Published: April 2011

AbstractA novel application, utilizing polyacrylamide‐g‐carboxymethyl cellulose (CMC‐g‐PAM) in concentrating dilute solutions of Bovine serum albumin (BSA), was investigated. The grafting reaction parameters were investigated and the hydrogel smartness was verified. FT‐IR proved that the grafting reaction occurred between the hydroxyl group located in anhydroglucose C2 position of CMC and the π‐bond of PAM and SEM confirmed a changed morphology to a fibrillar structure. The pH sensitivity was proved; as the grafted polymer attained its maximum swelling at pH 7.2 while the minimum swelling was observed under acidic conditions (pH 1‐3). The rate of water uptake in the grafted polymer hydrogel was higher than that of the homopolymer hydrogel and the swelling behaviors of both hydrogels obeyed second‐order kinetics. The tested hydrogel showed a high potency towards concentrating BSA solutions with a concentration factor of 1 to 4.5 times and recovery of 60–90%. The concentration factor increased linearly with increasing both the polymer concentration and the process time and decreased with the increase in the protein concentration. The grafted polymer had stable efficiency in the concentration process for 20 cycles. The obtained results have recommended the employment of the prepared CMC‐g‐PAM hydrogel in the down stream protein concentration process in the industrial scale. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Thermal behavior and kinetics during the stabilization of polyacrylonitrile precursor in inert gas
Authors: Xiao Shijie , Lv Honghong , Tong Yuanjian , Xu Lianghua , Chen Biaohua 
Published: April 2011

AbstractThe thermal behaviors of polyacrylonitrile precursor during thermal stabilization in inert gas were investigated by differential scanning calorimetry, thermomechanical analysis, and thermogravimetry. Combining these methods with the tracing of chemical changes by Fourier transform infrared spectroscopy indicated that complex reactions, including cyclization and pyrolytic reactions occurred sequentially. An imine‐enamine tautomeric structure was formed at around 240°C and was converted to a conjugated structure when the temperature was increased to 400°C. A thermal stabilization mechanism was proposed and confirmed experimentally by using a two‐step heating process. The apparent activation energies and the pre‐exponential factors for these stabilization reactions were also estimated by the Kissinger, Ozawa, and “Improved Coats‐Redfern” methods. To obtain a fit to the experiment data, a new kinetic model, named the “Three Regions Kinetic Model,” was proposed using the Improved Coats‐Redfern method. The applicability of this model and the prediction of the stabilization profile at a given heating rate were verified by plotting conversion rate against conversion profiles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Polymerization of styrene using novel bispyrazolylimine dinickel (II)/methylaluminoxane catalytic systems
Authors: Wang Yuan‐yuan , Li Ben‐xia , Zhu Fang‐ming , Gao Hai‐yang , Wu Qing 
Published: April 2011

AbstractThe polymerization of styrene with a series of bispyrazolylimine dinickel (II) complexes of bis‐2‐(C3HN2(R1)2‐3,5)(C(R2) = N(C6H3(CH3)2‐2,6)Ni2Br4 (complex 1: R1 = CH3, R2 = Ph; complex 2: R1 = CH3, R2 = 2,4,6‐trimethylphenyl; complex 3: R1 = R2 = Ph; complex 4: R1 = Ph, R2 = 2,4,6‐trimethylphenyl) in the presence of methylaluminoxane (MAO) was studied. The influences of polymerization parameters such as polymerization temperature, Al/Ni molar ratio, reaction time, and catalyst concentration on catalytic activity and molecular weight of the polystyrene were investigated in detail. The influence of the bulkiness of the substituents on polymerization activity was also studied. All of the four catalytic systems exhibited high activity (up to 10.50 × 105 gPS/(mol Ni h)) for styrene polymerization and provide polystyrene with moderate to low molecular weights (Mw = 4.76 × 104–0.71 × 104 g/mol) and narrower molecular weight distributions about 2. The obtained polystyrene was characterized by means of FTIR, 1H‐NMR, and 13C‐NMR techniques. The results indicated that the polystyrene was atactic polymer. The analysis of the end groups of polystyrene indicated that styrene polymerization with bispyrazolylimine dinickel complexes/MAO catalytic systems proceeded through a coordination mechanism. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
“Digit anatomy”: A new technique for learning anatomy using motor memory
Authors: Oh Chang‐Seok , Won Hyung‐Sun , Kim Kyong‐Jee , Jang Dong‐Su 
Published: April 2011

AbstractGestural motions of the hands and fingers are powerful tools for expressing meanings and concepts, and the nervous system has the capacity to retain multiple long‐term motor memories, especially including movements of the hands. We developed many sets of successive movements of both hands, referred to as “digit anatomy,” and made students practice the movements which express (1) the aortic arch, subclavian, and thoracoacromial arteries and their branches, (2) the celiac trunk, superior mesenteric artery and their branches, and formation of the portal vein, (3) the heart and the coronary arteries, and (4) the brachial, lumbar, and sacral plexuses. A feedback survey showed that digit anatomy was helpful for the students not only in memorizing anatomical structures but also in understanding their functions. Out of 40 students, 34 of them who learned anatomy with the help of digit anatomy were “very satisfied” or “generally satisfied” with this new teaching method. Digit anatomy that was used to express the aortic arch, subclavian, and thoracoacromial arteries and their branches was more helpful than those representing other structures. Although the movements of digit anatomy are expected to be remembered longer than the exact meaning of each movement, invoking the motor memory of the movement may help to make relearning of the same information easier and faster in the future. Anat Sci Educ 4:132–141, 2011. © 2011 American Association of Anatomists.
The almost sure asymptotic stability and pth moment asymptotic stability of nonlinear stochastic delay differential systems with polynomial growth
Authors: Liu Lei , Shen Yi 
Published: April 2011

AbstractIn this paper, we discuss the asymptotic stability of nonlinear stochastic delay differential systems (SDDSs) whose coefficients obey the polynomial growth condition. By applying some novel techniques, we establish some easily verifiable conditions under which such SDDSs are almost surely asymptotically stable and pth moment asymptotically stable. A nontrivial example is provided to illustrate the effectiveness of our results.Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Early fetal development of the intermediate tendon of the human digastricus and omohyoideus muscles: A critical difference in histogenesis
Authors: Katori Yukio , Hyun Kim Ji , Rodríguez‐Vázquez Jose Francisco , Kawase Tetsuaki , Murakami Gen , Hwan Cho Baik 
Published: April 2011

AbstractThe digastricus and omohyoideus muscles are known to carry two muscle bellies connected by an intermediate tendon. However, according to our histological observations of 22 fetuses (7–20 weeks of gestation), the mode of formation of the intermediate tendon was critically different between these two muscles. At 7–9 weeks, the posterior belly of the digastricus carried a definite intramuscular tendon continuous with a long descending tendon. The stylohyoideus, external carotid artery and hypoglossal nerve appeared to impede attachment of the tendon to the Reichert or hyoid cartilage. The digastricus anterior belly did not contain any intramuscular tendon, but desmin‐positive muscle fibers consistently surrounded a bulb‐like mesenchymal condensation at the caudal free end of the digastricus posterior tendon. Thus, most parts of the digastricus tendon were apparently derived from the posterior belly. In contrast, the omohyoideus always possessed a single long muscle belly until 15 weeks. The intermediate tendon first appeared at 15 weeks as a short plate‐like connective structure along the medial margin of the muscle. Vimentin immunoreactivity suggested the presence of mechanical stress along the plate‐like tissue, possibly due to bending of the long muscle. Muscle fibers were replaced by collagen fibers to form an intermediate tendon by 20 weeks. Clin. Anat. 24:843–852, 2011. © 2011 Wiley‐Liss, Inc.
Hierarchical Self‐Assembly of Amphiphilic Peptide Dendrons: Evolution of Diverse Chiral Nanostructures Through Hydrogel Formation Over a Wide pH Range
Authors: Duan Pengfei , Qin Long , Zhu Xuefeng , Liu Minghua 
Published: April 2011

AbstractAn amphiphilic dendron containing three dendrite L‐glutamic acid units and a long alkyl chain was synthesized by a convergent method. It was found that the dendron could form hydrogels over a wide pH range from 2 to 13. Moreover, accompanying the pH change, the compounds self‐assembled into various chiral structures: from helical nanotube, helical nanotube with a string of beads, and coiled superhelix to dendrite nanostructures, such as pine, feather, etc. A series of characterizations based on TEM observations, X‐ray diffraction and FTIR spectroscopic measurements revealed that the dendron formed a bilayer first and then hierarchically self‐assembled into various chiral nanostructures. The four carboxylic acid groups and three amide groups played an important role in the self‐assembly. The interaction between the multiamide groups stabilized the bilayer structures, whereas the ionization degree of the carboxylic acids was responsible for the formation of various chiral structures. The work presented a hydrogel system with wide pH adaptability and showed the regulation on chiral structures by simple pH variations.
Increasing the Isomerisation Kinetics of Azo Dyes by Chemical Bonding to Liquid‐Crystalline Polymers
Authors: Garcia‐Amorós Jaume , Finkelmann Heino , Velasco Dolores 
Published: April 2011

AbstractIt is well known that the proper substitution of the azobenzene core allows tuning the thermal cis‐to‐trans isomerisation kinetics of azo dyes. The thermal isomerisation process of nitro‐substituted azobenzenes is accelerated up to 13 times with respect to that in the common isotropic solvents when they are doped in nematic low molar mass liquid crystals. This kinetic acceleration is even stronger when these azo dyes are covalently linked to a nematic siloxane polymer. In this environment, the isomerisation process is accelerated more than 103 times. This effect is presented herein for the first time. The possible application of the networks obtained as possible photo‐actuators has been also considered.
On the Mechanism of Irreversible Carbon Dioxide Binding with a Frustrated Lewis Pair: Solvent‐Assisted Frustration and Transition‐State Entropic Encouragement
Authors: Kwon Hee Jae , Kim Hyun Woo , Rhee Young Min 
Published: April 2011

AbstractThe mechanism of irreversible carbon dioxide binding with a Lewis pair Mes3P:AlCl3 (Mes=2,4,6‐C6H2Me3) is computationally investigated to reveal that the steric congestion is not the driving force for the activation of CO2. Instead, we find that the specific solute–solvent interaction between the Lewis acid and a bromobenzene molecule lowers the effective binding energy of the Lewis pair. This solvation effect affects the reaction in a similar manner to the steric encumbering of conventional frustrated Lewis pairs. Additionally, the transition state toward the CO2 binding becomes extraordinarily flexible upon solvation. This flexibility encourages the adduct formation entropically and thus lowers the free‐energy barrier of the reaction. We conclude that this combination of energy‐barrier lowering through solvent‐assisted frustration and the entropic encouragement generates a feasible activation route for CO2 under mild conditions.