bluuebunny/crossref_metadata_2025_split huggingface dataset:
Raman Spectroscopy for Probing guest-host interactions in Metal Organic Frameworks
Authors: Nijem Nour , Roodenko Katy , Zhao Yonggang , Li Jing , Chabal Yves J. 
Published: September 2011

ABSTRACTSpectroscopic techniques such as IR and Raman are very powerful to understand guest-host interactions. Although these techniques are complementary, Raman spectroscopy has not been widely implemented as a tool to characterize these interactions. This study illustrates the use of Raman spectroscopy not only to probe the interactions experienced by a guest molecule but also to detect structural changes occurring in the framework upon loading. Weak interactions of adsorbed molecules with the framework are reflected in frequency and intensity variations in both Raman and IR absorption lines, as shown for the case of CO2, N2 and CH4 with Zn(bdc)(ted)0.5.
Precipitates formation and its impact in friction stir welded and post-heat-treated Inconel 718 alloy
Authors: Song Kuk Hyun , Kim Han Sol , Kim Won Yong 
Published: September 2011

ABSTRACTIn order to investigate the formation of precipitates such as MC carbides and intermetallic compounds in the friction stir welded and post-heat-treated Inconel 718 alloy, this work was carried out. Furthermore, the microstructural and mechanical properties of welds and post-heat-treated material were evaluated to identify the effect on precipitates formed during post-heat-treatment. Friction stir welding (FSW) was performed at a rotation speed of 200 rpm and welding speed of 150 mm/min; heat treatment was performed after welding at 720 °C for 8 hours in vacuum. As a result, the grain size due to FSW was notably refined from 5–20 μm in the base material to 1–3 μm in the stir zone; this was accompanied by dynamic recrystallization, which resulted in enhancements in the mechanical properties as compared to the base material. In particular, applying heat treatment after FSW led to improvements in the mechanical properties of the welds—the microhardness and tensile strength increased by more than 50% and 40% in fraction, respectively, as compared to FSW alone.
Limits for Antibody Affinity Maturation and Repertoire Diversification in Hypervaccinated Humans
Authors: Poulsen Tine Rugh , Jensen Allan , Haurum John S. , Andersen Peter S. 
Published: September 2011

Abstract
The immune system is known to generate a diverse panel of high-affinity Abs by adaptively improving the recognition of pathogens during ongoing immune responses. In this study, we report the biological limits for Ag-driven affinity maturation and repertoire diversification by analyzing Ab repertoires in two adult volunteers after each of three consecutive booster vaccinations with tetanus toxoid. Maturation of on-rates and off-rates occurred independently, indicating a kinetically controlled affinity maturation process. The third vaccination induced no significant changes in the distribution of somatic mutations and binding rate constants implying that the limits for affinity maturation and repertoire diversification had been reached. These fully matured Ab repertoires remained similar in size, genetically diverse, and dynamic. Somatic mutations and kinetic rate constants showed normal and log-normal distribution profiles, respectively. Mean values can therefore be considered as biological constants defining the observed boundaries. At physiological temperature, affinity maturation peaked at kon = 1.6 × 104 M−1 s−1 and koff = 1.7 × 10−4 s−1 leading to a maximum mean affinity of KD = 1.0 × 10−9 M. At ambient temperature, the average affinity increased to KD = 3.4 × 10−10 M mainly due to slower off-rates. This experimentally determined set of constants can be used as a benchmark for analysis of the maturation level of human Abs and Ab responses.
Restricted Aeroallergen Access to Airway Mucosal Dendritic Cells In Vivo Limits Allergen-Specific CD4+ T Cell Proliferation during the Induction of Inhalation Tolerance
Authors: Fear Vanessa S. , Burchell Jennifer T. , Lai Siew Ping , Wikstrom Matthew E. , Blank Fabian , von Garnier Christophe , Turner Debra J. , Sly Peter D. , Holt Patrick G. , Strickland Deborah S. , Stumbles Philip A. 
Published: September 2011

Abstract
Chronic innocuous aeroallergen exposure attenuates CD4+ T cell-mediated airways hyperresponsiveness in mice; however, the mechanism(s) remain unclear. We examined the role of airway mucosal dendritic cell (AMDC) subsets in this process using a multi-OVA aerosol-induced tolerance model in sensitized BALB/c mice. Aeroallergen capture by both CD11blo and CD11bhi AMDC and the delivery of OVA to airway draining lymph nodes by CD8α− migratory dendritic cells (DC) were decreased in vivo (but not in vitro) when compared with sensitized but nontolerant mice. This was functionally significant, because in vivo proliferation of OVA-specific CD4+ T cells was suppressed in airway draining lymph nodes of tolerized mice and could be restored by intranasal transfer of OVA-pulsed and activated exogenous DC, indicating a deficiency in Ag presentation by endogenous DC arriving from the airway mucosa. Bone marrow-derived DC Ag-presenting function was suppressed in multi-OVA tolerized mice, and allergen availability to airway APC populations was limited after multi-OVA exposure, as indicated by reduced OVA and dextran uptake by airway interstitial macrophages, with diffusion rather than localization of OVA across the airway mucosal surface. These data indicate that inhalation tolerance limits aeroallergen capture by AMDC subsets through a mechanism of bone marrow suppression of DC precursor function coupled with reduced Ag availability in vivo at the airway mucosa, resulting in limited Ag delivery to lymph nodes and hypoproliferation of allergen-specific CD4+ T cells.
Reciprocal Polarization of T and B Cells at the Immunological Synapse
Authors: Duchez Sophie , Rodrigues Magda , Bertrand Florie , Valitutti Salvatore 
Published: September 2011

Abstract
Cognate interactions between T and B lymphocytes lead to the formation of the immunological synapse (IS) where bidirectional activation signals are exchanged. Although the molecular architecture and the function of the IS have been studied extensively on the T cell side, little is known about events occurring during synapse formation in Ag-presenting B cells. We investigated the impact of BCR and TLR signaling on human B cell activation and on the T and B cell side of the IS. On the T cell side, we observed that T cells polarized toward both naive and previously activated B cells. Nevertheless, when T cells interacted with different B cells simultaneously, T cells selectively polarized their secretory machinery toward preactivated B cells. Furthermore, both naive and preactivated B cells reoriented their microtubule-organizing center toward the synaptic T cell during cognate interactions. This phenomenon was rapid and not dependent on T cell secretory activity. Interestingly, not only the microtubule-organizing center but also the Golgi apparatus and Lamp-3+ and MHC class II+ vesicles all repositioned beneath the IS, suggesting that the entire endocytic/exocytic B cell compartment was reoriented toward the T cell. Taken together, our results show that the B cell activation status fine-tunes T cell polarization responses and reveal the capacity of naive and activated B cells to polarize toward T cells during cognate interactions.
Selective Resistance of CD44hi T Cells to p53-Dependent Cell Death Results in Persistence of Immunologic Memory after Total Body Irradiation
Authors: Yao Zhenyu , Jones Jennifer , Kohrt Holbrook , Strober Samuel 
Published: September 2011

Abstract
Our previous studies showed that treatment of mice with total body irradiation (TBI) or total lymphoid tissue irradiation markedly changes the balance of residual T cell subsets to favor CD4+CD44hi NKT cells because of the differential resistance of the latter subset to cell death. The object of the current study was to further elucidate the changed balance and mechanisms of differential radioresistance of T cell subsets after graded doses of TBI. The experimental results showed that CD4+ T cells were markedly more resistant than CD8+ T cells, and CD44hi T cells, including NKT cells and memory T cells, were markedly more resistant than CD44lo (naive) T cells. The memory T cells immunized to alloantigens persisted even after myeloablative (1000 cGy) TBI and were able to prevent engraftment of bone marrow transplants. Although T cell death after 1000 cGy was prevented in p53−/− mice, there was progressive T cell death in p53−/− mice at higher doses. Although p53-dependent T cell death changed the balance of subsets, p53-independent T cell death did not. In conclusion, resistance of CD44hi T cells to p53-dependent cell death results in the persistence of immunological memory after TBI and can explain the immune-mediated rejection of marrow transplants in sensitized recipients.
Interaction of Ras with P110γ Is Required for Thymic β-Selection in the Mouse
Authors: Janas Michelle L. , Turner Martin 
Published: September 2011

AbstractThymocytes are tested for productive rearrangement of the tcrb locus by expression of a pre-TCR in a process termed β-selection, which requires both Notch1 and CXCR4 signaling. It has been shown that activation of the GTPase Ras allows thymocytes to proliferate and differentiate in the absence of a Pre-TCR; the direct targets of Ras at this checkpoint have not been identified, however. Mice with a mutant allele of p110γ unable to bind active Ras revealed that CXCR4-mediated PI3K activation is Ras dependent. The Ras–p110γ interaction was necessary for efficient β-selection–promoted proliferation but was dispensable for the survival or differentiation of thymocytes. Uncoupling Ras from p110γ provides unambiguous identification of a Ras interaction required for thymic β-selection.
Electron on a cylinder with topological defects in a homogeneous magnetic field
Authors: Filgueiras C. , de Oliveira B.F. 
Published: September 2011

AbstractIn this work we study the effects of the geometry and topology of a cylinder on the energy levels of an electron moving in a homogeneous magnetic field. We consider the existence of topological defects as a screw dislocation and a disclination. When we take the region of movement as the full cylindrical surface, we find that, by increasing the strength of the screw dislocation, the dispersion on the electronic energy levels is affected and monotonically increasing. For an electron moving in an almost flat region we show that the dispersion on the Landau levels decrease monotonically as we increase the strength of the screw dislocation. The lowest Landau level can reach a zero value, leaving the energy of the system solely given by the geometry of the cylinder, which does not depend on the magnetic field. In both situations, as we change the deficit angle of the disclination, we observe that the energy levels are shifted and the magnitude of such shift depends on the magnetic field. The Landau levels for a flat sample are recovered in the limit of an infinite cylinder radius.
Quantum anticentrifugal potential in a bent waveguide
Authors: Dandoloff R. , Atanasov V. 
Published: September 2011

AbstractWe show the existence of an anticentrifugal force for a quantum particle in a bent waveguide. This effect may be observed in interference experiments which are sensitive to the additional phase of the wavefunction gained in the bent regions and can find application in distinguishing between straight and bent geometries.
Reply to the Comment of G. Feulner
Authors: Weber W. 
Published: September 2011

AbstractIn my reply I present a re‐analysis of the data of the Smithsonian Astrophysical Observatory (SAO). For this, a new data reduction method is introduced, allowing a drastic lowering of data scatter, so that the time series of the reduced data clearly shows the ≈︁ 1 % variation of the terrestric solar irradiance in parallel with solar activity. The implications are discussed.
Succinate production in Escherichia coli
Authors: Thakker Chandresh , Martínez Irene , San Ka‐Yiu , Bennett George N. 
Published: September 2011

AbstractSuccinate has been recognized as an important platform chemical that can be produced from biomass. While a number of organisms are capable of succinate production naturally, this review focuses on the engineering of Escherichia coli for the production of four‐carbon dicarboxylic acid. Important features of a succinate production system are to achieve an optimal balance of reducing equivalents generated by consumption of the feedstock, while maximizing the amount of carbon channeled into the product. Aerobic and anaerobic production strains have been developed and applied to production from glucose and other abundant carbon sources. Metabolic engineering methods and strain evolution have been used and supplemented by the recent application of systems biology and in silico modeling tools to construct optimal production strains. The metabolic capacity of the production strain, the requirement for efficient recovery of succinate, and the reliability of the performance under scaleup are important in the overall process. The costs of the overall biorefinery‐compatible process will determine the economic commercialization of succinate and its impact in larger chemical markets.
Social Desirability Bias in Survey Research on Sustainable Development in Small Firms: an Exploratory Analysis of Survey Mode Effect
Authors: Roxas Banjo , Lindsay Val 
Published: September 2011

ABSTRACTSurvey methodology has become an increasingly popular weapon of choice in conducting research on the topic of environmental sustainability in the small firm context. However, conventional application of survey research in many empirical studies tends to ignore the inherent issues associated with the mode of administration of survey questionnaires. One of these issues is social desirability bias (SDB) arising from survey modes such as face to face, the assisted type of survey questionnaire administration and mailed or purely self‐administered survey. This study is an analysis of survey data generated by two modes: purely self‐administered and survey enumerator assisted. The paper argues that the presence of an enumerator in the workplace or actual site of the business to administer the survey will motivate the respondents to provide more accurate information about the firms' environmental sustainability knowledge and practices. The article offers suggestions to address SDB in carrying out surveys about environmental sustainability in small firms. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.
Immunoregulatory and effector activities in human cutaneous and mucosal Leishmaniasis: Understanding mechanisms of pathology
Authors: Dutra Walderez O. , de Faria Daniela Rodrigues , Machado Paulo Roberto Lima , Guimarães Luiz Henrique , Schriefer Albert , Carvalho Edgar , Gollob Kenneth J. 
Published: September 2011

AbstractIndividuals infected with Leishmania braziliensis may develop the relatively benign localized cutaneous (CL) form or the mucosal (ML) form of the disease, which represents a more severe and mutilating variation. Interaction between parasite and host cells, as well as the genetic background of the host, are important determinants of the immune response, which is critical in determining disease outcome. Our studies over the years have been designed to determine the immunoregulatory and effector functions that culminate in the formation of lesions in CL and ML disease and how these host response factors may be better understood for design of novel therapies and prophylaxis. By studying the immune response from CL and ML patients in both the peripheral blood and in situ, we have learned much concerning the dynamics of the host–pathogen interaction that leads to the development of CL and ML. We used multiparameter flow cytometry to study the immunoregulatory profiles of the peripheral blood leukocytes, as well as laser scanning confocal microscopy to examine in situ several aspects of the local response, including the intensity of the inflammatory infiltrate, the cellular composition, inflammatory and anti‐inflammatory cytokine expression, and the expression of the effector cytotoxic molecule, granzyme A, in lesions from CL and ML patients. Moreover, the application of correlative analysis between these immunological parameters has helped shed light on disease progression in CL and ML. These findings are reviewed within the context of understanding cellular and molecular mechanisms associated with the development of pathology in these diseases through a comparative analysis of the clinical forms, CL and ML, as well as of studies derived from peripheral blood and lesions. Drug Dev Res 72:430–436, 2011. © 2011 Wiley‐Liss, Inc.
Trace Levels Determination of Ammonium by Flow Injection Analysis Using Gas‐Diffusion and Capacitively Coupled Contactless Conductivity Detection
Authors: Braz Henrique L. , Ito Débora T. , da Silva José A. Fracassi , do Lago Claudimir L. , Pedrotti Jairo J. 
Published: September 2011

AbstractA sensitive analytical method based on gas‐diffusion flow injection system for ammonium ion determination at trace levels with capacitively coupled contactless conductivity detection (C4D) is described. The effects of the chemical composition of the acceptor stream, operating frequency of the conductivity detector, acceptor and donor flow rates, injected volume, and some potential interferents were evaluated. By injecting 100 µL samples, the analytical method showed linear response for ammonium from 2.0 up to 100 µmol L−1 and a limit of detection of 0.8 µmol L−1 (14 ppb). At a flow rate of 0.10 mL min−1 for the acceptor solution, an analytical throughput of 35 injections per hour was achieved. The new flow injection system was successfully applied for ammonium determination in rainwater from São Paulo city.
Adoptive T cell therapy promotes the emergence of genomically altered tumor escape variants
Authors: Kaluza Karen M. , Thompson Jill M. , Kottke Timothy J. , Flynn Gilmer Heather C. , Knutson Darlene L. , Vile Richard G. 
Published: September 2011

AbstractAdoptive T cell therapy has been proven effective against melanoma in mice and humans. However, because most responses are incomplete or transient, cures remain rare. To maximize the efficacy of this therapy, it will be essential to gain a better understanding of the processes which result in tumor relapse. We studied these processes using B16ova murine melanoma and adoptive transfer of OT‐I T cells. Transfer of T cells as a single therapy provided a significant survival benefit for mice with established subcutaneous tumors. However, tumors which initially regressed often recurred. By analyzing tumors which emerged in the presence of a potent OT‐I response, we identified a novel tumor escape mechanism in which tumor cells evaded T cell pressure by undergoing major genomic changes involving loss of the gene encoding the target tumor antigen. Furthermore, we show that these in vivo processes can be recapitulated in vitro using T cell/tumor cell co‐cultures. A single round of in vitro co‐culture led to significant loss of the ova gene and a tumor cell population with rapidly induced and diverse karyotypic changes. Although these current studies focus on the model OVA antigen, the finding that T cells can directly promote genomic instability has important implications for the development of adoptive T cell therapies.
Cancer recurrence after surgery: Direct and indirect effects of anesthetic agents*
Authors: Tavare Aniket N. , Perry Nicholas J.S. , Benzonana Laura L. , Takata Masao , Ma Daqing 
Published: September 2011

AbstractSurgery is of paramount importance in the management of solid tumors as definitive resection can be totally curative. Nonetheless, metastatic recurrence after surgery remains a major cause of morbidity and mortality. Interest in the impact of the perioperative period on cancer recurrence is now growing rapidly, with recent research suggesting that some anesthetics or anesthetic techniques may influence the pathophysiology of postoperative metastatic spread. Our review examines the most widely postulated mechanisms for this, including the impact of anesthesia on neuroendocrine and immune function. We also consider evidence for a direct impact on tumor cell signaling pathways based on findings from organ protection research. These studies have demonstrated that certain volatile anaesthetics confer cytoprotective properties to exposed cells and lead to significant upregulation of Hypoxia Inducible Factor‐1α (HIF‐1α). This ubiquitous transcription factor exerts many effects in cancer: its activity has been linked with more aggressive phenotypes and poorer clinical prognosis. It is proposed that such an upregulation of HIFs in tumor cells by these anesthetics may contribute to a tumor's recurrence by stimulating cytoprotective or protumorigenic behavior in residual cells. Conversely, other anesthetic agents appear to downregulate HIFs or cause negligible effect and thus may prove more suitable for use in cancer surgery. As anesthetic drugs are given at a point of potentially high vulnerability in terms of dissemination and establishment of metastases, there is an urgent need to determine the most appropriate anesthetic strategy for surgical oncology so that the optimal techniques are used to maximize long‐term survival.
Olfactory metamorphosis in the coastal tailed frog Ascaphus truei (Amphibia, Anura, Leiopelmatidae)
Authors: Benzekri Noëlle A. , Reiss John O. 
Published: September 2011

AbstractThe structure of the olfactory organ in larvae and adults of the basal anuran Ascaphus truei was examined using light micrography, electron micrography, and resin casts of the nasal cavity. The larval olfactory organ consists of nonsensory anterior and posterior nasal tubes connected to a large, main olfactory cavity containing olfactory epithelium; the vomeronasal organ is a ventrolateral diverticulum of this cavity. A small patch of olfactory epithelium (the “epithelial band”) also is present in the preoral buccal cavity, anterolateral to the choana. The main olfactory epithelium and epithelial band have both microvillar and ciliated receptor cells, and both microvillar and ciliated supporting cells. The epithelial band also contains secretory ciliated supporting cells. The vomeronasal epithelium contains only microvillar receptor cells. After metamorphosis, the adult olfactory organ is divided into the three typical anuran olfactory chambers: the principal, middle, and inferior cavities. The anterior part of the principal cavity contains a “larval type” epithelium that has both microvillar and ciliated receptor cells and both microvillar and ciliated supporting cells, whereas the posterior part is lined with an “adult‐type” epithelium that has only ciliated receptor cells and microvillar supporting cells. The middle cavity is nonsensory. The vomeronasal epithelium of the inferior cavity resembles that of larvae but is distinguished by a novel type of microvillar cell. The presence of two distinct types of olfactory epithelium in the principal cavity of adult A. truei is unique among previously described anuran olfactory organs. A comparative review suggests that the anterior olfactory epithelium is homologous with the “recessus olfactorius” of other anurans and with the accessory nasal cavity of pipids and functions to detect water‐borne odorants. J. Morphol. 2011. © 2011 Wiley Periodicals, Inc.