bluuebunny/crossref_metadata_2025_split huggingface dataset:
CD1d and CD1c Expression in Human B Cells Is Regulated by Activation and Retinoic Acid Receptor Signaling
Authors: Allan Lenka L. , Stax Annelein M. , Zheng Dong-Jun , Chung Brian K. , Kozak Fred K. , Tan Rusung , van den Elzen Peter 
Published: March 2011

Abstract
B cell activation and Ab production in response to protein Ags requires presentation of peptides for recruitment of T cell help. We and others have recently demonstrated that B cells can also acquire innate help by presenting lipid Ags via CD1d to NKT cells. Given the newfound contribution of NKT cells to humoral immunity, we sought to identify the pathways that regulate CD1 molecule expression in human B cells. We show that ex vivo, activated and memory B cells expressed lower levels of CD1d compared with resting, naive, and marginal zone-like B cells. In vitro, CD1d was downregulated by all forms of B cell activation, leaving a narrow temporal window in which B cells could activate NKT cells. CD1c expression and function also decreased following activation by CD40L alone, whereas activation via the BCR significantly upregulated CD1c, particularly on marginal zone-like B cells. We found that the CD40L-induced downreglation of CD1d and CD1c correlated with diminished expression of retinoic acid receptor α (RARα) response genes, an effect that was reversed by RARα agonists. However, BCR-induced upregulation of CD1c was independent of the RAR pathway. Our findings that both CD1d and CD1c are upregulated by RARα signaling in human B cells is distinct from effects reported in dendritic cells, in which CD1c is inversely downregulated. One functional consequence of CD1d upregulation by retinoic acid was NKT cell cytotoxicity toward B cells. These results are central to our understanding of how CD1-restricted T cells may control humoral immunity.
Bcl-2 Allows Effector and Memory CD8+ T Cells To Tolerate Higher Expression of Bim
Authors: Kurtulus Sema , Tripathi Pulak , Moreno-Fernandez Maria E. , Sholl Allyson , Katz Jonathan D. , Grimes H. Leighton , Hildeman David A. 
Published: March 2011

Abstract
As acute infections resolve, most effector CD8+ T cells die, whereas some persist and become memory T cells. Recent work showed that subsets of effector CD8+ T cells, identified by reciprocal expression of killer cell lectin-like receptor G1 (KLRG1) and CD127, have different lifespans. Similar to previous reports, we found that effector CD8+ T cells reported to have a longer lifespan (i.e., KLRG1lowCD127high) have increased levels of Bcl-2 compared with their shorter-lived KLRG1highCD127low counterparts. Surprisingly, we found that these effector KLRG1lowCD127high CD8+ T cells also had increased levels of Bim compared with KLRG1highCD127low cells. Similar effects were observed in memory cells, in which CD8+ central memory T cells expressed higher levels of Bim and Bcl-2 than did CD8+ effector memory T cells. Using both pharmacologic and genetic approaches, we found that survival of both subsets of effector and memory CD8+ T cells required Bcl-2 to combat the proapoptotic activity of Bim. Interestingly, inhibition or absence of Bcl-2 led to significantly decreased expression of Bim in surviving effector and memory T cells. In addition, manipulation of Bcl-2 levels by IL-7 or IL-15 also affected expression of Bim in effector CD8+ T cells. Finally, we found that Bim levels were significantly increased in effector CD8+ T cells lacking Bax and Bak. Together, these data indicate that cells having the highest levels of Bim are selected against during contraction of the response and that Bcl-2 determines the level of Bim that effector and memory T cells can tolerate.
Stereochemical Basis for a Unified Structure Activity Theory of Aromatic and Heterocyclic Rings in Selected Opioids and Opioid Peptides
Authors: Goldberg Joel S. 
Published: March 2011

This paper presents a novel unified theory of the structure activity relationship of opioids and opioid peptides. It is hypothesized that a virtual or known heterocyclic ring exists in all opioids which have activity in humans, and this ring occupies relative to the aromatic ring of the drug, approximately the same plane in space as the piperidine ring of morphine. Since the rings of morphine are rigid, and the aromatic and piperidine rings are critical structural components for morphine's analgesic properties, the rigid morphine molecule allows for approximations of the aromatic and heterocyclic relationships in subsequent drug models where bond rotations are common. This hypothesis and five propositions are supported by stereochemistry and experimental observations. Proposition #1 The structure of morphine provides a template. Proposition #2 Steric hindrance of some centric portion of the piperidine ring explains antagonist properties of naloxone, naltrexone and alvimopam. Proposition #3 Methadone has an active conformation which contains a virtual heterocyclic ring which explains its analgesic activity and racemic properties. Proposition #4 The piperidine ring of fentanyl can assume the morphine position under conditions of nitrogen inversion. Proposition #5 The first 3 amino acid sequences of beta endorphin (l-try-gly-gly) and the active opioid dipeptide, l-tyr-pro, (as a result of a peptide turn and zwitterion bonding) form a virtual piperazine-like ring which is similar in size, shape and location to the heterocyclic rings of morphine, meperidine, and methadone. Potential flaws in this theory are discussed. This theory could be important for future analgesic drug design.
A Characterization of Bergman Spaces on the Unit Ball of ℂn. II
Authors: Li Songxiao , Wulan Hasi , Zhu Kehe 
Published: March 2011

AbstractIt has been shown that a holomorphic function f in the unit ball of ℂn belongs to the weighted Bergman space , p > n + 1 + α, if and only if the function | f(z) – f(w)|/|1 – 〈z, w〉| is in Lp( × , dvβ × dvβ), where β = (p + α – n – 1)/2 and dvβ(z) = (1 – |z|2)βdv(z). In this paper we consider the range 0 < p < n + 1 + α and show that in this case, f ∈ (i) if and only if the function | f(z) – f(w)|/|1 – hz, wi| is in Lp( × , dvα × dvα), (ii) if and only if the function | f(z)– f(w)|/|z–w| is in Lp( × , dvα × dvα). We think the revealed difference in the weights for the double integrals between the cases 0 < p < n + 1 + α and p > n + 1 + α is particularly interesting.
Birmingham Hip Resurfacing in Patients who are Seventy Years of Age or Older
Authors: Carrothers Andrew D. , Gilbert Robin E. , Richardson James B. 
Published: March 2011

There is no published literature to support mid to long term results of hip resurfacing (HR) arthroplasty in patients over the age of 70 years. The purpose of our study was to evaluate the function HR in this age group (70 or older at the time of surgery) at medium to long term follow-up. Between July 1997 and November 2002, the Oswestry Outcome Centre independently and prospectively collected data on 5000 Birmingham Hip Resurfacings (BHRs). 106 had been implanted in elderly patients who were 70 years of age or older. The post-operative Harris and Merle D'Aubigné and Postel (MDP) hip scores and causes for revision were used to ascertain function and implant survival. Hip scores for the older BHR patients were compared with those from younger patients. The average age at surgery of the elderly BHR cohort was 73.2 years (range, 70.0 to 87.9 years) with a mean follow-up of 7.1 years (range, 0.5 to 10.9 years). Four patients had a femoral neck fracture and required conversion to a conventional total hip replacement. There were no patients lost to follow-up and no dislocations in this series. The median Harris hip score (HHS) was significantly better in the younger BHR group compared with the elderly BHR group, (96 vs. 94 p=0.008). There was no significant difference in recovery rates after surgery. There was a significantly higher rate of revision in women than men among the elderly patients (male= 1 of 65 (1.5%); women = 3 of 19 (15.8%), p=0.03). At latest follow-up the elderly patients continued to function well when compared with the younger BHR patients. There was a high mid to long term success rate after HR in patients who were 70 years of age or older, without the failure burden possibly anticipated. Elderly patients had a poorer functional outcome, but a difference in HHS of two points may be of only minor clinical significance.
Prevention Better than Cure. Avoiding Steal Syndrome with Proximal Radial or Ulnar Arteriovenous Fistulae
Authors: Whittaker Laura , Bakran Ali 
Published: March 2011

Background Steal syndrome is a significant complication of arteriovenous fistulae (AVF). We wanted to assess an alternative technique to reduce the incidence of steal syndrome and add an extra option for vascular access for long-term hemodialysis patients. Methods All patients who underwent proximal radial or ulnar artery AVF between 2003 and 2007 were evaluated retrospectively. Results There were 58 patients, 35 men and 23 women, and the median age was 60 years (range 19–85 years). The proximal radial artery was used in 50 (89%) of cases and the ulnar artery in 8. Three fistulae (5%) failed in the first week, 3 others failed later, prior to use leading to a 90% successful patency rate. One diabetic patient developed steal syndrome and re-presented to the surgeons at a late stage when they had finger ulceration and it was decided to ligate the fistula in this case. Thus, the overall incidence of steal syndrome was low at 2%. Conclusions It is suggested that arterio-venous fistulae using proximal radial or ulnar arteries can be performed before brachio-cephalic fistulae since they offer long-term patency and reduced incidence of steal syndrome. Brachio-cephalic AVF can be performed subsequently if necessary.
Wilms tumor in a patient with 22q11.2 microdeletion
Authors: Finch Paul T. , Pivnick Eniko K. , Furman Wayne , Odom Christine C. 
Published: March 2011

Abstract22q11.2 deletion syndrome is the most common microdeletion syndrome. Wilms tumor is one of the most common solid tumors in childhood yet 22q11.2 deletion and Wilms tumor only once have been reported in the same patient. Here we describe a young patient with subtle clinical findings suggestive of 22q11.2 at the time of diagnosis who subsequently developed Wilms tumor. We assert the importance of a low threshold for screening for 22q11.2 deletion and the associated phenotypes and maintaining vigilance in screening for common primary malignancies in patients with known 22q11.2 deletion. © 2011 Wiley‐Liss, Inc.
Molecular systematics and phylogeography ofCebus capucinus(Cebidae, Primates) in Colombia and Costa Rica by means of the mitochondrial COII gene
Authors: Ruiz‐Garcia Manuel , Castillo Maria Ignacia , Ledezma Andrea , Leguizamon Norberto , Sánchez Ronald , Chinchilla Misael , Gutierrez‐Espeleta Gustavo A. 
Published: March 2011

AbstractWe propose the first molecular systematic hypothesis for the origin and evolution ofCebus capucinusbased on an analysis of 710 base pairs (bp) of the cytochrome c oxidase subunit II (COII) mitochondrial gene in 121C. capucinusspecimens sampled in the wild. The animals came from the borders of Guatemala and Belize, Costa Rica, and eight different departments of Colombia (Antioquia, Chocó, Sucre, Bolivar, Córdoba, Magdalena, Cauca, and Valle del Cauca). Three different and significant haplotype lineages were found in Colombia living sympatrically in the same departments. They all presented high levels of gene diversity but the third Colombian gene pool was determined likely to be the most ancestral lineage. The second Colombian mitochondrial (mt) haplogroup is likely the source of origin of the unique Central America mt haplogroup that was detected. Our molecular population genetics data do not agree with the existence of two well‐defined subspecies in Central America (limitaneusandimitator). This Central America mt haplogroup showed significantly less genetic diversity than the Colombian mt haplogroups. All theC. capucinusanalyzed showed evidence of historical population expansions. The temporal splits among these fourC. capucinuslineages were related to the completion of the Panamanian land bridge as well as to climatic changes during the Quaternary Period. Am. J. Primatol. 74:366–380, 2012. © 2011 Wiley Periodicals, Inc.
Predation risk and the interspecific association of two Brazilian Atlantic forest primates inCabrucaagroforest
Authors: Oliveira Leonardo C. , Dietz James M. 
Published: March 2011

AbstractForming interspecific associations is one of many strategies adopted by primates in order to avoid predation. In addition to improved predator detection and avoidance, benefits of interspecific associations relate to improved foraging efficiency. In this study we tested these two hypotheses explaining associations between the endangered golden‐headed lion tamarin,Leontopithecus chrysomelasand the sympatric Wied's marmoset,Callithrix kuhlii. We estimated predation risk by recording the number of encounters between lion tamarins and potential predators incabrucaagroforest (shaded cacao plantation) and in mosaic forest (a mix ofcabruca, primary and secondary forest). To evaluate if the association between the two species was related to foraging benefits we recorded the number of associations between the two species when the lion tamarins were eating and when they were not eating. To test if the association occurred to improve predator detection and avoidance, we evaluated if associations between the species were more frequent in areas with higher predation risk and during the part of the day when predation risk is higher. We also compared the number of associations 3 months before birth events and 3 months after, when the lion tamarins are more susceptible to predation. Predation risk, mainly by raptors, was significantly higher incabrucathan in mosaic forest (0.17 and 0.05 encounters with predators per hour of observation, respectively). Associations were significantly more frequent after birth events and during the part of the day when predation risk was also higher (5–6 am until noon). We did not observe any direct evidence of foraging‐related advantages of interspecific associations for the lion tamarins. The tamarins did not associate more when they were foraging. Our findings suggest that lion tamarins are more exposed to predation incabrucathan in mosaic forest and associations between lion tamarins and Wied's marmosets are related to predation avoidance. Am. J. Primatol. 73:852–860, 2011. © 2011 Wiley‐Liss, Inc.
Zintl‐Ionen, Käfigverbindungen und intermetalloide Cluster der Elemente der 14. und 15. Gruppe
Authors: Scharfe Sandra , Kraus Florian , Stegmaier Saskia , Schier Annette , Fässler Thomas F. 
Published: March 2011

AbstractLange Zeit betrachtete man die Zintl‐Ionen der Elemente der 14. und 15. Gruppe für bemerkenswerte, in der Festkörperchemie angesiedelte Spezies, die einerseits durch ihre unerwarteten Zusammensetzungen und faszinierenden Strukturen auffielen, andererseits aber von nur eingeschränkter Bedeutung waren. Neue Aufmerksamkeit erfuhren die Zintl‐Ionen, als man feststellte, dass diese in festen Zintl‐Phasen vorgeformten Spezies aus ihrem Kristallverband extrahiert, in geeigneten Solventien gelöst und damit als Reaktanten und Bausteine in der Lösungschemie verfügbar gemacht werden können. Der steile Anstieg von Forschungsaktivitäten in diesem Gebiet führte zu einer Fülle neuer Verbindungen, beispielsweise durch Funktionalisierung dieser Zintl‐Ionen mit organischen Gruppen und metallorganischen Fragmenten, durch oxidative Kupplungsreaktionen unter Bildung von Dimeren, Oligomeren und Polymeren oder durch Einlagerung von Metallatomen, wobei endohedrale Cluster und intermetallische Verbindungen gebildet werden, von denen einige vielversprechende Perspektiven für Anwendungen in den Materialwissenschaften zeigen. Dieser Aufsatz berichtet über die enormen Fortschritte in der Chemie der Zintl‐Ionen mit Hauptaugenmerk auf deren Herstellung, Eigenschaften, Strukturen und theoretischer Beschreibung.
Zintl Ions, Cage Compounds, and Intermetalloid Clusters of Group 14 and Group 15 Elements
Authors: Scharfe Sandra , Kraus Florian , Stegmaier Saskia , Schier Annette , Fässler Thomas F. 
Published: March 2011

AbstractFor a long time, Zintl ions of Group 14 and 15 elements were considered to be remarkable species domiciled in solid‐state chemistry that have unexpected stoichiometries and fascinating structures, but were of limited relevance. The revival of Zintl ions was heralded by the observation that these species, preformed in solid‐state Zintl phases, can be extracted from the lattice of the solids and dissolved in appropriate solvents, and thus become available as reactants and building blocks in solution chemistry. The recent upsurge of research activity in this fast‐growing field has now provided a rich plethora of new compounds, for example by substitution of these Zintl ions with organic groups and organometallic fragments, by oxidative coupling reactions leading to dimers, oligomers, or polymers, or by the inclusion of metal atoms under formation of endohedral cluster species and intermetalloid compounds; some of these species have good prospects in applications in materials science. This Review presents the enormous progress that has been made in Zintl ion chemistry with an emphasis on syntheses, properties, structures, and theoretical treatments.
Ethylene/α‐olefin copolymerization by nonbridged (cyclopentadienyl)(aryloxy)titanium(IV) dichloride/AliBu3/Ph3CB(C6F5)4 catalyst systems
Authors: Li Hongchun , Niu Yongsheng 
Published: March 2011

AbstractA series of nonbridged (cyclopentadienyl) (aryloxy)titanium(IV) complexes of the type, (η5‐Cp′)(OAr)TiCl2 [OAr = O‐2,4,6‐tBu3C6H2 and Cp′ = Me5C5 (1), Me4PhC5 (2), and 1,2‐Ph2‐4‐MeC5H2 (3)], were prepared and used for the copolymerization of ethylene with α‐olefins (e.g., 1‐hexene, 1‐octene, and 1‐octadecene) in presence of AliBu3 and Ph3CB(C6F5)4 (TIBA/B). The effect of the catalyst structure, comonomer, and reaction conditions on the catalytic activity, comonomer incorporation, and molecular weight of the produced copolymers was examined. The substituents on the cyclopentadienyl group of the ligand in 1–3 play an important role in the catalytic activity and comonomer incorporation. The 1/TIBA/B catalyst system exhibits the highest catalytic activity, while the 3/TIBA/B catalyst system yields copolymers with the highest comonomer incorporation under the same conditions. The reactivity ratio product values are smaller than those by ordinary metallocene type, which indicates that the copolymerization of ethylene with 1‐hexene, 1‐octene, and 1‐octadecene by the 1–3/TIBA/B catalyst systems does not proceed in a random manner. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of thermal aging on the mechanical and barrier properties of an e‐PTFE/Nomex® moisture membrane used in firefighters' protective suits
Authors: El Aidani Rachid , Dolez Patricia I. , Vu‐Khanh Toan 
Published: March 2011

AbstractMoisture membranes play a key role in high performance protective clothing by preventing outside water to get in while allowing the human body to perspire properly. However, these membranes are confronted to high environmental constraints, in particular within firefighters' protective clothing. The resulting aging effect may lead to modifications of their performances, for example their mechanical or barrier properties. In this study, the thermal aging of an e‐PTFE/Nomex® moisture membrane was carried out at five temperatures between 190 and 320°C. The effect of aging on the mechanical performance was assessed by tensile tests and trapezoid tear strength measurements. Variation in the moisture membrane water vapor permeability due to aging was also studied. Large modifications in the membrane mechanical properties as a result of thermal aging were recorded. It was associated in part with a degradation of the Nomex® fibers. The membrane water vapor permeability was observed to decrease with aging time below 220°C while values larger than those corresponding to the unaged material were measured above that temperature. This was possibly related to the occurrence of two competing phenomena relative to water vapor permeability: closure of pores in the e‐PTFE laminate and creation of cracks and holes. These results show that the aging of the moisture membrane must be considered carefully while estimating the service life of protective clothing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Microfluidic formation of monodispersed spherical microgels composed of triple‐network crosslinking
Authors: Zhang Hanwei , Betz Amy , Qadeer Aisha , Attinger Daniel , Chen Weiliam 
Published: March 2011

AbstractA microfluidic emulsification method for producing monodispersed microgels from a triple interpenetrating network (3XN) hydrogel was reported. This 3XN system is comprised of minimally modified natural GRAS materials, partially oxidized dextran (Odex), Teleostean, and N‐carboxyethyl chitosan (CEC), without the need of utilizing extraneous crosslinkers or photo‐initiators, which has been proved to be a novel biodegradable and mechanically strong in‐situ gelable hydrogel systems. A microfluidic chip was specifically designed to produce microgels from the 3XN hydrogel system. The study shows that microfluidic emulsification method could yield microgels with better size and morphology than the conventional in‐emulsion‐crosslinking method, and the size of microgels could be modulated by simply adjusting the flow rates of the oil and/or the individual precursor fluids. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis, characterization, and mechanical property of poly(urethane‐glycidyl methacrylate‐methyl methacrylate) hybrid polymers
Authors: Lee Jung Min , Kim Joon‐Seop , Cheong In Woo , Kim Jung Hyun 
Published: March 2011

AbstractHybrid particles of polyurethane (PU) containing a number of small poly(methyl methacrylate) (PMMA) nanoparticles inside were prepared using glycidyl methacrylate (GMA) monomer as a linker between PU and PMMA; the resulting polymers were poly (urethane‐glycidyl methacrylate‐methyl methacrylate) (PUGM). It was found that the average particle size (Dp) of the PU particles decreased by the inclusion of PMMA particles possibly owing to the low‐solution viscosity of PU. However, Dp of the PUGM hybrid particles increased with increasing the number of covalent bonds between PMMA and PU, which might be due to decreasing the amount of ionic groups per PU chain. Subsequently, the tensile properties of the films made of the PUGM hybrid particles were investigated. It was observed that the modulus of the PU films increased upon the addition of PMMA particle because of a filler effect. In addition, it was seen that the modulus of PUGM hybrid films increased further with increasing the number of covalent bonds. This was attributed to “restricted mobility” of PU chains anchored to the PMMA particles. It was also observed that the tensile strength changed only slightly for PUGM particles, suggesting that the PU matrix was probably responsible for the necking behavior of the films. The elongation of the samples was found to depend on both the presence of covalent bonds between the PMMA particles and PU matrix and the reduced mobility of the PU chains anchored to PMMA particles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011