bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antigenic Variation in Treponema pallidum: TprK Sequence Diversity Accumulates in Response to Immune Pressure during Experimental Syphilis
Authors: Giacani Lorenzo , Molini Barbara J. , Kim Eric Y. , Godornes B. Charmie , Leader B. Troy , Tantalo Lauren C. , Centurion-Lara Arturo , Lukehart Sheila A. 
Published: February 2010

Abstract
Pathogens that cause chronic infections often employ antigenic variation to evade the immune response and persist in the host. In Treponema pallidum (T. pallidum), the causative agent of syphilis, the TprK Ag undergoes variation of seven V regions (V1–V7) by nonreciprocal recombination of silent donor cassettes with the tprK expression site. These V regions are the targets of the host humoral immune response during experimental infection. The present study addresses the causal role of the acquired immune response in the selection of TprK variants in two ways: 1) by investigating TprK variants arising in immunocompetent versus immunosuppressed hosts; and 2) by investigating the effect of prior specific immunization on selection of TprK variants during infection. V region diversity, particularly in V6, accumulates more rapidly in immunocompetent rabbits than in pharmacologically immunosuppressed rabbits (treated with weekly injections of methylprednisolone acetate). In a complementary experiment, rabbits preimmunized with V6 region synthetic peptides had more rapid accumulation of V6 variant treponemes than control rabbits. These studies demonstrate that the host immune response selects against specific TprK epitopes expressed on T. pallidum, resulting in immune selection of new TprK variants during infection, confirming a role for antigenic variation in syphilis.
Integrin αMβ2 Clustering Triggers Phosphorylation and Activation of Protein Kinase Cδ that Regulates Transcription Factor Foxp1 Expression in Monocytes
Authors: Xue Zhi-Hong , Zhao Chang-Qing , Chua Geok-Lin , Tan Sze-Wah , Tang Xiao-Yan , Wong Siew-Cheng , Tan Suet-Mien 
Published: February 2010

Abstract
Integrins are type I membrane and heterodimeric (αβ) cell adhesion receptors. Intracellular signals triggered by ligand-bound integrins are important for cell growth, differentiation, and migration. Integrin αMβ2 plays key roles in myeloid cell adhesion, phagocytosis, and degranulation. In this study, we show that protein kinase C (PKC) δ is involved in αMβ2 signaling. In human monocytic U937 cells and peripheral blood monocytes, αMβ2 clustering induced PKCδ translocation to the plasma membrane, followed by Tyr311 phosphorylation and activation of PKCδ by the src family kinases Hck and Lyn. Interestingly, αMβ2-induced PKCδ Tyr311 phosphorylation was not mediated by the tyrosine kinase Syk, which is a well reported kinase in β2 integrin signaling. Analysis of the β2 cytoplasmic tail showed that the sequence Asn727-Ser734 is important in αMβ2-induced PKCδ Tyr311 phosphorylation. It has been shown that αMβ2 clustering regulates the expression the transcription factor Foxp1 that has a role in monocyte differentiation. We show that Foxp1 expression was reduced in monocytes that were allowed to adhere to human microvascular endothelial cells. However, the expression of Foxp1 was not affected in monocytes that were treated with PKCδ-targeting small interfering RNA, suggesting that PKCδ regulates Foxp1 expression. These results demonstrate a role of PKCδ in αMβ2-mediated Foxp1 regulation in monocytes.
How Far Are We from Making Metamaterials by Self‐Organization? The Microstructure of Highly Anisotropic Particles with an SRR‐Like Geometry
Authors: Pawlak Dorota A. , Turczynski Sebastian , Gajc Marcin , Kolodziejak Katarzyna , Diduszko Ryszard , Rozniatowski Krzysztof , Smalc Julita , Vendik Irina 
Published: March 2010

AbstractMetamaterials offer new unusual electromagnetic properties, which have already been demonstrated, and many postulated new functionalities are yet to be realized. Currently, however, metamaterials are mostly limited by narrow band behavior, high losses, and limitation in making genuinely 3D materials. In order to overcome these problems an overlap between metamaterial concepts and materials science is necessary. Engineered self‐organization is presented as a future approach to metamaterial manufacturing. Using directional solidification of eutectics, the first experimental realization of self‐organized particles with a split‐ring resonator‐like cross section is demonstrated. This unusual morphology/microstructure of the eutectic composite has a fractal character. With the use of TEM and XRD the clear influence of the atomic crystal arrangement on the microstructure geometry is presented. The materials obtained present very high anisotropy and can be obtained in large pieces. Metallodielectric structures can be created by etching and filling the space with metal. The next steps in the development of self‐organized materials exhibiting unusual properties are discussed.
Interface Modifications of InAs Quantum‐Dots Solids and their Effects on FET Performance
Authors: Soreni‐Harari Michal , Mocatta David , Zimin Marina , Gannot Yair , Banin Uri , Tessler Nir 
Published: March 2010

AbstractInAs nanocrystals field‐effect transistors with an ON/OFF ratio of 105 are reported. By tailoring the interface regions in the active layer step‐by‐step, the evolution of the ON/OFF ratio can be followed from approximately 5 all the way to around 105. The formation of a semiconducting solid from colloidal nanocrystals is achieved through targeted design of the nanocrystal–nanocrystal interaction. The manipulation characteristics of the nanocrystal interfaces include the matrix surrounding the inorganic core, the interparticle distance, and the order of nanocrystals in the 3D array. Through careful analysis of device characteristics following each treatment, the effect of each on the physical properties of the films are able to be verified. The enhanced performance is related to interparticle spacing, reduction in sub‐gap states, and better electronic order (lower σ parameter). Films with enhanced charge transport qualities retain their quantum‐confined characteristics throughout the procedure, thus making them useful for optoelectronic applications.
Nanostructures for Thermoelectric Applications: Synthesis, Growth Mechanism, and Property Studies
Authors: Zhang Genqiang , Yu Qingxuan , Wang Wei , Li Xiaoguang 
Published: March 2010

AbstractBoth heterostructures and hollow nanostructures have been predicted as candidates with excellent thermoelectric performance. In this Research News areticle, recent advances with regard to synthetic strategies, growth mechanisms, and thermoelectric properties of one‐dimensional heterostructures (segmented and core/shell) and tubular nanostructures are reported. The thermoelectric property studies of Te/Bi core/shell heterostructured nanowires and Bi2Te3 nanotubes indicate that the Seebeck coefficient and thermal conductivity of these materials can be optimized to improve their thermoelectric performance. In addition, the current issues and future research directions for promising thermoelectric nanostructures will be discussed on the basis of these experimental results.
A computational fluid dynamics design of a carbon dioxide sorption circulating fluidized bed
Authors: Chalermsinsuwan Benjapon , Piumsomboon Pornpote , Gidaspow Dimitri 
Published: March 2010

AbstractA kinetic theory based hydrodynamic model with experimentally determined sorption rates for reaction of CO2 with K2CO3 solid sorbent is used to design a compact circulating fluidized bed sorption‐regeneration system for CO2 removal from flue gases. Because of high solids fluxes, the sorber does not require internal or external cooling. The output is verified by computing the granular temperatures, particle viscosities, dispersion, and mass transfer coefficients. These properties agree with reported measurement values except the radial dispersion coefficients, which are much higher due to the larger bed diameter. With the solid sorbent prepared according to published information, the CO2 removal percentage at the riser top is 69.16%. To improve the CO2 removal, an effort is needed to develop a better sorbent or to simply lower the inlet gas velocity to operate in a denser mode, leading to a larger system. Also, the effect of temperature rise on the removal efficiency is investigated. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Axial segregation in bubbling gas‐fluidized beds with Gaussian and lognormal distributions of Geldart Group B particles
Authors: Chew Jia Wei , Wolz Jeffrey R. , Hrenya Christine M. 
Published: March 2010

AbstractBubbling, gas‐fluidized bed experiments involving Geldart Group B particles with continuous‐size distributions have been carried out. Sand of various widths of Gaussian or lognormal distributions were completely fluidized, then axial concentration profiles were obtained from frozen‐bed sectioning. Similar to previous works on binary systems, results show that mean particle diameter decreases with increasing bed height, and that wider Gaussian distributions show increased segregation extents. Surprisingly, however, lognormal distributions exhibit a nonmonotonic segregation trend with respect to distribution widths. In addition, the shape of the local‐size distribution is largely preserved with respect to that of the overall distribution. These findings on the nature of local‐size distribution provide experimental confirmation of previous results for granular and gas‐solid simulations. Lastly, an interesting observation is that although monodisperse Geldart Group D particles cannot be completely fluidized, their presence in lognormal distributions investigated still results in complete fluidization of all particles. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Impact of deposit aging and surface roughness on thermal fouling: Distributed model
Authors: Coletti F. , Ishiyama E. M. , Paterson W. R. , Wilson D. I. , Macchietto S. 
Published: March 2010

AbstractA kinetic model was recently proposed to describe the effect of aging on deposit thermal conductivity and the thermal performance of a shell‐and‐tube heat exchanger undergoing crude oil fouling. The model is adapted for implementation within a dynamic, distributed system with spatial and temporal distributions, relaxing several of the previous assumptions. The evolution of surface roughness is also considered, using conjectural linear and asymptotic functions. Simulations are performed for a single tube representative of a refinery exchanger. The results demonstrate the substantial effects over time of aging and roughness on heat transfer and pressure drop. Roughness effects yield apparently negative initial fouling resistances, as reported in some experimental tests. The importance of accounting for roughness dynamics in short time scale pilot plant scale tests and aging over longer time scales in industrial applications is highlighted. © 2010 American Institute of Chemical Engineers AIChE J, 2010
An exact method for determining local solid fractions in discrete element method simulations
Authors: Freireich Ben , Kodam Madhusudhan , Wassgren Carl 
Published: March 2010

AbstractA novel solid fraction algorithm is presented which accounts for the partial volume of a sphere straddling cuboidal bin boundaries. The algorithm accounts for spheres intersecting a single plane (face), two perpendicular planes (edge), or three perpendicular planes (corner). Comparisons are made against the more common algorithm in which the solid fraction is determined by assigning the sphere's total volume to the bin in which the sphere's center of volume (COV) is located. Bin size‐to‐sphere diameter ratios >30 must be used to give errors <5% when using the traditional method when applied to simple cubic (SC) and hexagonal packing assemblies. Bin size‐to‐sphere diameter ratios larger than five are required for random sphere packings. Although time averaged solid fraction measurements are similar using either the exact or COV solid fraction schemes, the scatter in the COV method is much larger than for the exact method. © 2010 American Institute of Chemical Engineers AIChE J, 2010
High‐efficiency power production from coal with carbon capture
Authors: Adams Thomas A. , Barton Paul I. 
Published: March 2010

AbstractA zero‐emissions power plant with high efficiency is presented. Syngas, produced by the gasification of coal, is shifted to produce H2 which in turn fuels stacks of solid oxide fuel cells. Because the fuel cells maintain separate anode and cathode streams, air can be used as the oxygen source without diluting the fuel exhaust with nitrogen. This enables recovery of CO2 from the exhaust with a very small energy penalty. As a result, an absorption‐based CO2 recovery process is avoided, as well as the production of large quantities of high‐purity O2, allowing a high overall thermal efficiency and essentially eliminating the energy penalty for carbon capture. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Immigrants as crime victims: Experiences of personal nonfatal victimization
Authors: Wheeler Krista , Zhao Weiyan , Kelleher Kelly , Stallones Lorann , Xiang Huiyun 
Published: March 2010

AbstractBackgroundImmigrants to the United States are disproportionately victims of homicide mortality in and outside the workplace. Examining their experiences with nonfatal victimization may be helpful in understanding immigrant vulnerability to violence.MethodsWe compared the annual prevalence of nonfatal personal victimization experienced by immigrant and US‐born adults by sociodemographics, employment, occupation, industry, smoking, alcohol and drug use using data from Wave 1 National Epidemiologic Survey on Alcohol and Related Conditions.ResultsThe prevalence of victimization among immigrants was comparable to that among US‐born adults [3.84% (95% CI: 3.18–4.63) vs. 4.10% (95% CI: 3.77–4.44)]. Lower percentages of victimization experienced by immigrants were seen among the unmarried, those age 30–44 years, and among residents of central city areas as compared to those groups among the US‐born. For immigrants entering the US as youth, the victimization prevalence declines with greater years of residency in US. Multivariate logistic regression models suggest that, the odds of victimization was significantly associated with age, family income, marital status, central city residency, smoking, and drug use while employment status was not a significant factor. Immigrant workers with farming/forestry occupations might face a higher risk of being victims of violence than their US‐born counterparts.ConclusionsThe prevalence of victimization among immigrants was comparable to that among US‐born adults. Employment status and industry/occupation overall were not significant risk factors for becoming victims of violence. Am. J. Ind. Med. 53:435–442, 2010. © 2010 Wiley‐Liss, Inc.
A global perspective of migration and occupational health
Authors: Schenker Marc B. 
Published: March 2010

AbstractBackgroundGlobal migration has dramatically increased over the past decade and is at an all‐time high, approaching 200 million persons per year. Demographics and economic interdependence suggest that immigration will continue for the near future at record high levels.MethodsA review of the few studies that have investigated occupational injury and illness rates among immigrant populations.ResultsExisting data indicate that higher rates of fatal and non‐fatal injuries are common compared to native populations. This increase is in part due to immigrants working in higher risk occupations (e.g., agriculture, construction), but occupational morbidity and mortality is higher among immigrants than native‐born workers within occupational categories.ConclusionsResearch is needed to identify the causes of increased risk among immigrants and to provide direction to effective public health interventions. Research methods must be adapted to different epidemiologic characteristics of immigrant populations, including lack of standard sampling frames, different language and culture from the dominant culture, and precarious work status. Am. J. Ind. Med. 53:329–337, 2010. © 2010 Wiley‐Liss, Inc.
A flexible content‐based image retrieval model and a customizable system for the retrieval of shapes
Authors: Bordogna Gloria , Pagani Marco 
Published: March 2010

AbstractThe authors describe a flexible model and a system for content‐based image retrieval of objects' shapes. Flexibility is intended as the possibility of customizing the system behavior to the user's needs and perceptions. This is achieved by allowing users to modify the retrieval function. The system implementing this model uses multiple representations to characterize some macroscopic characteristics of the objects shapes. Specifically, the shape indexes describe the global features of the object's contour (represented by the Fourier coefficients), the contour's irregularities (represented by the multifractal spectrum), and the presence of concavities and convexities (represented by the contour scale space distribution). During a query formulation, the user can specify both the preference for the macroscopic shape aspects that he or she considers meaningful for the retrieval, and the desired level of accuracy of the matching, which means that the visual query shape must be considered with a given tolerance in representing the desired shapes. The evaluation experiments showed that this system can be suited to different retrieval behaviors, and that, generally, the combination of the multiple shape representations increases both recall and precision with respect to the application of any single representation.
Maternal exposures to endocrine disrupting chemicals and hypospadias in offspring
Authors: Giordano Felice , Abballe Annalisa , De Felip Elena , di Domenico Alessandro , Ferro Fabio , Grammatico Paola , Ingelido Anna Maria , Marra Valentina , Marrocco Giacinto , Vallasciani Santiago , Figà‐Talamanca Irene 
Published: March 2010

AbstractBACKGROUNDPrenatal exposures to endocrine‐disrupting chemicals (EDCs) are suspected risk factors in the etiology of hypospadias. The aim of this case‐control study was to test the hypothesis of an association between maternal environmental exposures to EDCs and hypospadias in the offspring.METHODSDetailed questionnaire data on occupational and dietary exposures to EDCs in the perinatal period were collected from 80 mothers with hypospadiac infants and from 80 mothers with healthy controls within 24 months of childbirth. Maternal exposure to selected EDCs was also ascertained by measuring the concentration of dichlorodiphenyldichloroethylene, hexachlorobenzene, and several polychlorinated biphenyl congeners in the serum of primiparous mothers of 37 cases and 21 controls.RESULTSThe risk to bear an hypospadiac infant was associated with perinatal maternal occupational exposures to EDCs evaluated by a job‐exposure matrix: jobs with exposure to one class of EDCs (odds ratios [OR]crude, 2.83; 95% confidence intervals [CI], 1.32–6.07; ORadjusted, 2.44; 95% CI, 1.06–5.61) and jobs with exposure to more than one group of EDCs (ORcrude, 4.27; 95% CI, 1.43–12.78; ORadjusted, 4.11; 95%CI, 1.34–12.59). Increase in risk was also found among mothers consuming a diet rich in fish or shellfish (ORcrude, 3.41; 95% CI, 1.42–8.23; ORadjusted, 2.73; 95%CI, 1.09–6.82). Serum hexachlorobenzene concentration above the median of all subjects was significantly associated with the risk of hypospadias (ORadjusted, 5.50; 95% CI, 1.24–24.31).CONCLUSIONSThis study, although based on a limited number of cases, for the first time provides evidence of an association between maternal exposure to EDCs, in particular elevated plasma hexachlorobenzene concentration, and the development of hypospadias in the offspring. Birth Defects Research (Part A), 2010. © 2010 Wiley‐Liss, Inc.
Contactless passive diagnosis for brain intracranial applications: A study using dielectric matching materials
Authors: Gouzouasis Ioannis A. , Karathanasis Konstantinos T. , Karanasiou Irene S. , Uzunoglu Nikolaos K. 
Published: March 2010

AbstractA prototype system for passive intracranial monitoring using microwave radiometry is proposed. It comprises an ellipsoidal conductive wall cavity to achieve beamforming and focusing, in conjunction with sensitive multiband receivers for detection. The system has already shown the capability to provide temperature and/or conductivity variations in phantoms and biological tissue. In this article, a variant of the initially constructed modality is theoretically and experimentally investigated. Specifically, dielectric matching materials are used in an effort to improve the system's focusing attributes. The theoretical study investigates the effect of dielectric matching materials on the system's detection depth, whereas measurements with phantoms focus on the investigation of the system's detection level and spatial resolution. The combined results suggest that the dielectric matching layers lead to the improvement of the system's detection depth and temperature detection level. Also, the system's spatial resolution is explored at various experimental setups. Theoretical and experimental results conclude that with the appropriate combination of operation frequencies and dielectric layers, it is possible to monitor areas of interest inside human head models with a variety of detection depths and spatial resolutions. Bioelectromagnetics 31:335–349, 2010. © 2010 Wiley‐Liss, Inc.
Inline ultrafiltration
Authors: Teske Christopher A. , Lebreton Benedicte , Reis Robert van 
Published: March 2010

AbstractInline ultrafiltration (UF) can significantly increase the recoverable mass of biopharmaceutical products when pool tank volumes are limiting. Using relatively small commercially available ultrafiltration cassettes, a proof‐of‐concept study demonstrates that inline UF can significantly increase recoverable mass in an antibody purification process. With ever‐increasing cell culture titers pushing product masses to higher levels, inline UF offers a relatively easy‐to‐implement and less disruptive alternative to installing larger pool tanks and enables more cost‐effective production utilizing facilities designed for smaller bulk sizes. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Refolding of denatured/reduced lysozyme at high concentrations by artificial molecular chaperone‐ion exchange chromatography
Authors: Wang Chaozhan , Zhang Qinming , Cheng Yan , Wang Lili 
Published: March 2010

AbstractDevelopment of high efficiency and low cost protein refolding methods is a highlighted research focus in biotechnology. Artificial molecular chaperone (AMC) and protein folding liquid chromatography (PFLC) are two attractive refolding methods developed in recent years. In the present work, AMC and one branch of PFLC, ion exchange chromatography (IEC), are integrated to form a new refolding method, artificial molecular chaperone‐ion exchange chromatography (AMC‐IEC). This new method is applied to the refolding of a widely used model protein, urea‐denatured/dithiothreitol‐reduced lysozyme. Many factors influencing the refolding of lysozyme, such as urea concentration, β‐cyclodextrin concentration, molar ratio of detergent to protein, mobile phase flow rate, and type of detergent, were investigated, respectively, to optimize the conditions for lysozyme refolding by AMC‐IEC. Compared with normal IEC refolding method, the activity recoveries of lysozyme obtained by AMC‐IEC were much higher in the investigated range of initial protein concentrations. Moreover, the activity recoveries obtained by using this newly developed refolding method were still quite high for denatured/reduced lysozyme at high initial concentrations. When the initial protein concentration was 200 mg mL−1, the activity recovery was over 60%. In addition, the lifetime of the chromatographic column during AMC‐IEC was much longer than that during protein refolding by normal IEC. Therefore, AMC‐IEC is a high efficient and low cost protein refolding method. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010