bluuebunny/crossref_metadata_2025_split huggingface dataset:
Histone acetylation is essential for ANG‐II‐induced IGF‐IIR gene expression in H9c2 cardiomyoblast cells and pathologically hypertensive rat heart
Authors: Chu Chun‐Hsien , Lo Jeng‐Fan , Hu Wei‐Syun , Lu Ru‐Band , Chang Mu‐Hsin , Tsai Fuu‐Jen , Tsai Chang‐Hai , Weng Yueh‐Shan , Tzang Bor‐Show , Huang Chih‐Yang 
Published: March 2011

AbstractThe IGF‐II/mannose 6‐phosphate receptor (IGF‐IIR/Man‐6‐P) up‐regulation correlates with heart disease progression and its signaling cascades directly trigger pathological cardiac hypertrophy, fibrosis, and cardiomyocytes apoptosis. IGF‐IIR gene expression/ suppression is able to prevent myocardial remodeling. However, the regulating mechanisms for the IGF‐IIR gene remain unclear. This study performed reverse transcriptase PCR (RT‐PCR) and methylation‐specific PCR (MS‐PCR) to detect expression and DNA methylation of CpG islands within the IGF‐IIR genomic DNA region. Our finding revealed that the IGF‐IIR gene was up‐regulated both in H9c2 cells treated with tumor necrosis factor‐alpha (TNF‐α), lipopolysaccharide (LPS), angiotensin II (ANGII) and inomycin, and age‐dependently in spontaneously hypertensive rat (SHR) heart. For the DNA methylation study, although there were four CpG islands within IGF‐IIR genomic regions, the DNA methylation distribution showed no change either in cells treated with ANGII or in the SHR heart. Using chemical inhibitors to individually block histone acetyltransferase (HAT) and histone deacetylase (HDAC) activity, we found that histone acetylation was essential for ANGII‐induced IGF‐IIR gene expression using RT‐PCR and luciferase assay. The Chromatin immuno‐precipitation assay indicated that acetyl‐Histone H3 and acetyl‐Histone H4 associated with the IGF‐IIR promoter increased in the presence of ANGII, otherwise methyl‐CpG binding domain protein 2 (MeCP2) is disassociated with this. Taken together, this study demonstrates that histone acetylation plays a critical role in IGF‐IIR up‐regulation during pathological cardiac diseases and might provide a targeting gene in transcriptional therapies for the failing heart. J. Cell. Physiol. 227: 259–268, 2012. © 2011 Wiley Periodicals, Inc.
Case report: A case of light chain deposition disease involving liver and stomach with chronic hepatitis C virus infection and hepatocellular carcinoma
Authors: Kwon Jung Hee , Jeong Sook‐Hyang , Kim Jin‐Wook , Bang Soo‐Mee , Kim Haeryoung , Kim Young Hoon , Song Sang Hoon 
Published: March 2011

AbstractLight chain deposition disease (LCDD) is a rare, plasma cell proliferative disorder characterized by mainly abnormal light chain deposition in various organs. Hepatitis C virus (HCV) is a hepatotrophic and lymphotrophic virus and significantly related to B‐cell proliferation. This is a case report of systemic LCDD involving liver, stomach, bone marrow, and probably kidney, in a patient with HCV‐related hepatocellular carcinoma (HCC). A 62‐year‐old man with chronic HCV infection who presented with a small HCC in segment 8 of the liver and nephrotic syndrome showed kappa typed immunoglobulin light chain depositions in biopsy specimens of bone marrow, stomach, and non‐tumorous liver parenchyma. After treatment of the HCC with transarterial chemoembolization, antiviral therapy for chronic hepatitis C was started. The patient showed early virologic response at 12 weeks of treatment; however, antiviral therapy was discontinued due to adverse effects and he was lost to follow‐up. This is the first case of LCDD involving the liver and stomach in a patient with chronic HCV infection and HCC, which may represent LCDD as a rare HCV‐associated B cell proliferative disease. J. Med. Virol. 83:810–814, 2011. © 2011 Wiley‐Liss, Inc.
A 2000‐year lipid biomarker record preserved in a stalagmite from north‐west Scotland
Authors: Blyth Alison J. , Baker Andy , Thomas Louise E. , Van Calsteren Peter 
Published: March 2011

AbstractPrevious studies on lipid biomarkers preserved in Chinese stalagmites have indicated that ratios of low‐molecular‐weight (LMW) to high‐molecular‐weight (HMW) n‐alkanes, n‐alkan‐2‐ones, n‐alkanols and n‐alkanoic acids can be used as an index of vegetation versus microbial organic matter input to the system and, by extension, a marker of climatic changes, with increases in the proportion of LMW compounds coinciding with colder periods. Here we test whether this hypothesis is equally applicable to a different geographical region (north‐west Scotland), by examining a stalagmite record of the past 200 years, and a wider range of lipid markers. We also test the applicability of other lipid proxies in this context, including the use of n‐alkane ratios, to interpret vegetation changes, and unsaturated alkanoic acid ratios as climatic indicators. The results show that lipid proxies preserved in stalagmites, and especially those related to vegetation, are potentially extremely useful in palaeoenvironmental research. Of particular value is the use of C27/C31 n‐alkane ratios as a proxy for vegetation change, clearly indicating variations between herbaceous and arboreal cover. This proxy has now been successfully applied to samples from diverse environments, and can be considered sufficiently robust to be of use in analysing future stalagmite records. It will be of particular value in areas where reliable pollen records are not available, as is often the case with deeper cave deposits. However, the division between LMW and HMW aliphatic compounds is not a clear‐cut case of microbial versus plant activity, with the changes in LMW compounds relating more closely to those in their HMW analogues than in specific bacterial biomarkers. The use of unsaturated alkanoic acid ratios here gives conflicting results, with the observed variation through time depending on the isomer measured. The discrepancies between the findings of this study and previous work are likely to be due to the varying controls on the lipids (original organic matter input, and compound degradation), which in turn will be affected by whether the main climatic limiting factor on the soil is temperature or precipitation. This suggests that lipid proxies preserved in stalagmites must be interpreted with care, particularly in the case of bacterial compounds which may be derived from within the cave or from the soil. However, many of these issues can be resolved by the use of multi‐proxy studies. Copyright © 2011 John Wiley & Sons, Ltd.
Elmendorf Tear Test of Polyethylene Films: Mechanical Interpretation and Model
Authors: Kissin Yury V. 
Published: March 2011

AbstractA physical model of one of the principal end‐use tests of film manufactured from linear low‐density and low‐density PE resins, the Elmendorf tear test (ASTM D1922, ISO 6383‐2), is described. According to this model, the tear test of film is a special case of a high‐speed stress/strain measurement performed on a polymer sample with a varying cross‐section. The tear resistance of film is a function of all the parameters that characterize the stress/strain curve of the resin: stresses and strains at the yield, the necking, and the breaking points. The model affords estimations of tear resistance of semi‐crystalline PE film and provides explanations for differences between tear strength of film manufactured from different types of resins. magnified image
The pivotal role of mass spectrometry in determining the presence of chemical contaminants in food raw materials
Authors: Mohamed Rayane , Guy Philippe A. 
Published: March 2011

AbstractDuring recent years, a rising interest from consumers and various governmental organizations towards the quality of food has continuously been observed. Human intervention across the different stages of the food supply chain can lead to the presence of several types of chemical contaminants in food‐based products. On a normal daily consumption basis, some of these chemicals are not harmful; however, for those that present a risk to consumers, legislation rules were established to specify tolerance levels or in some cases the total forbiddance of these specific contaminants. Hence, the use of appropriate analytical tools is recommended to properly identify chemical contaminants. In that context, mass spectrometry (MS)‐based techniques coupled or not to chromatography offer a vast panel of features such as sensitivity, selectivity, quantification at trace levels, and/or structural elucidation. Because of the complexity of food‐based matrices, sample preparation is a crucial step before final detection. In the present manuscript, we review the contribution and the potentialities of MS‐based techniques to ensure the absence of chemical contaminants in food‐based products. © 2010 Wiley Periodicals, Inc., Mass Spec Rev 30:1073–1095, 2011
Efficient generation of pareto‐optimal topologies for compliance optimization
Authors: Turevsky Inna , Suresh Krishnan 
Published: March 2011

AbstractIn multi‐objective optimization, a design is defined to beit pareto‐optimal if no other design exists that is better with respect to one objective, and as good with respect to other objectives. In this paper, we first show that if a topology is pareto‐optimal, then it must satisfy certain properties associated with the topological sensitivity field, i.e. no further comparison is necessary. This, in turn, leads to a deterministic, i.e. non‐stochastic, method for efficiently generating pareto‐optimal topologies using the classic fixed‐point iteration scheme. The proposed method is illustrated, and compared against SIMP‐based methods, through numerical examples. In this paper, the proposed method of generating pareto‐optimal topologies is limited to bi‐objective optimization, namely compliance–volume and compliance–compliance. The future work will focus on extending the method to non‐compliance and higher dimensional pareto optimization. Copyright © 2011 John Wiley & Sons, Ltd.
Folic acid‐conjugated depolymerized quaternized chitosan as potential targeted gene delivery vector
Authors: Morris Viola B , Pillai Chennakkattu K S , Sharma Chandra P 
Published: March 2011

AbstractLigand‐conjugated delivery vectors that target over‐expressed cell surface receptors have a potential impact on gene therapy. In the study reported, high‐molecular‐weight chitosan was depolymerized to medium and low molecular weight and trimethylated to render the polymer soluble over a wider pH range. Folate conjugation was introduced to the quarternized derivative to improve gene transfection efficiency. Complexes of the folic acid‐conjugated trimethylated depolymerized chitosan (FTMC) with plasmid DNA (pDNA) formed core–shell nanostructured particles. Gel electrophoretic band retardation showed efficient condensation of DNA. These derivatives and their complexes with pDNA were tested for toxicity and haemocompatibility and were found to be significantly less toxic and haemocompatible than polyethyleneimine. Transfection efficiency and nuclear uptake properties were tested in the human KB oral epidermoid cell line, which over‐expresses the folate receptor in the presence of 10% serum. Among the four FTMC derivatives investigated, folic acid‐conjugated chitosan having low molecular weight and medium folate conjugation was found to be a potential vector for gene delivery applications with good transfection and nuclear uptake properties, as proved by YOYO labelling of pDNA. Copyright © 2011 Society of Chemical Industry
Chitosan nanoparticles: a contribution to nanomedicine
Authors: Peniche Hazel , Peniche Carlos 
Published: March 2011

AbstractChitosan is a cationic polysaccharide that finds diverse applications in medicine and pharmacy because of its excellent biological qualities: it is biocompatible, biodegradable, mucoadhesive and non‐toxic, and exhibits antimicrobial, antiviral and immunoadjuvant properties. It can be easily processed in diverse forms, such as films, threads, tablets, membranes and microparticles/nanoparticles, allowing the design of a variety of medical and pharmacological devices adaptable to end purposes. In particular, chitosan nanoparticles have become of great interest as polymeric platforms for the development of new pharmacological and therapeutic drug release systems with improved biodistribution and increased specificity and sensitivity, and reduced pharmacological toxicity. Chitosan nanoparticles have been found appropriate for non‐invasive routes of drug administration: oral, nasal, pulmonary and ocular routes. These applications are facilitated by the absorption‐enhancing effect of chitosan. Additionally, chitosan nanoparticles have been proposed as non‐viral vectors in gene therapy and have shown adjuvant effect in vaccines. This paper reviews the main procedures developed for preparing chitosan nanoparticles. Moreover, it illustrates the state of the art of chitosan nanoparticle applications in drug delivery. Copyright © 2011 Society of Chemical Industry
Elevated expression levels of ANXA11, integrins β3 and α3, and TNF‐α contribute to a candidate proteomic signature in urine for kidney allograft rejection
Authors: Srivastava Meera , Eidelman Ofer , Torosyan Yelizaveta , Jozwik Catherine , Mannon Roslyn B. , Pollard Harvey B. 
Published: March 2011

AbstractPurpose: Kidney transplantation is the treatment of choice for end stage renal disease, with long‐term allograft loss being the major obstacle, and for which potential treatments are based on a histological diagnosis. The problem is that markers for predicting graft rejection are limited in number, are invasive, and are quite non‐specific. We have hypothesized that protein biomarkers might be discovered in the urine of patients when acute or chronic rejection might be occurring.Experimental design: We have established a workflow in which initial screening for candidate biomarkers is first performed using urine samples on large‐scale antibody microarrays. This approach generated several dozen candidates. The next step is to qualify some of the strongest signals using the high‐throughput Reverse Capture Protein Microarray platform.Results: Four top candidates including ANXA11, Integrin α3, Integrin β3 and TNF‐α, initially identified by the antibody microarray platform, were all qualified using Reverse Capture Protein Microarrays. We also used receiver operating condition (ROC) curves to independently quantify the specificity and sensitivity of these four analytes.Conclusions and clinical relevance: The present data suggest that these novel four analytes in the urine, together or independently, may contribute to a robust and quantitative urine proteomic signature for diagnosing acute or chronic rejection of renal allografts.
Constraining local structure can speed up folding by promoting structural polarization of the folding pathway
Authors: Buck Patrick M. , Bystroff Christopher 
Published: March 2011

AbstractThe pathway which proteins take to fold can be influenced from the earliest events of structure formation. In this light, it was both predicted and confirmed that increasing the stiffness of a beta hairpin turn decreased the size of the transition state ensemble (TSE), while increasing the folding rate. Thus, there appears to be a relationship between conformationally restricting the TSE and increasing the folding rate, at least for beta hairpin turns. In this study, we hypothesize that the enormous sampling necessary to fold even two‐state folding proteins in silico could be reduced if local structure constraints were used to restrict structural heterogeneity by polarizing folding pathways or forcing folding into preferred routes. Using a Gō model, we fold Chymotrypsin Inhibitor 2 (CI‐2) and the src SH3 domain after constraining local sequence windows to their native structure by rigid body dynamics (RBD). Trajectories were monitored for any changes to the folding pathway and differences in the kinetics compared with unconstrained simulations. Constraining local structure decreases folding time two‐fold for 41% of src SH3 windows and 45% of CI‐2 windows. For both proteins, folding times are never significantly increased after constraining any window. Structural polarization of the folding pathway appears to explain these rate increases. Folding rate enhancements are consistent with the goal to reduce sampling time necessary to reach native structures during folding simulations. As anticipated, not all constrained windows showed an equal decrease in folding time. We conclude by analyzing these differences and explain why RBD may be the preferred way to constrain structure.
Development of an organic vapor sensor based on functionalized porous silicon
Authors: Badilla J. P. , Rojas D. C. , López V. , Fahlman B. D. , Ramírez‐Porras A. 
Published: March 2011

AbstractFunctionalization of hydrofluoric acid‐etched crystalline silicon surfaces were performed using 4‐aminopyridine. This treatment was employed to perform an organic interface with the exterior ambient. The obtained treated surfaces were exposed to different organic vapors while keeping track of their electric conductance to assess their sensing abilities. Results for these tests are provided.
Growth of AlGaN/GaN heterostructure on vicinal m‐plane free‐standing GaN substrates prepared by the Na flux method
Authors: Isobe Yasuhiro , Iida Daisuke , Sakakibara Tatsuyuki , Iwaya Motoaki , Takeuchi Tetsuya , Kamiyama Satoshi , Akasaki Isamu , Amano Hiroshi , Imade Mamoru , Kitaoka Yasuo , Mori Yusuke 
Published: March 2011

AbstractWe fabricated and characterized AlGaN/GaN heterostructure growth by MOVPE on vicinal m‐plane free‐standing GaN substrates prepared by the Na flux method. The miscut angle in the LPE‐GaN substrate has a great influence on the surface morphology and crystalline quality of epitaxial GaN and AlGaN films. In particular, AlGaN/GaN on a 4° miscut‐angle LPE‐GaN substrate shows large step bunching, small‐miscut‐angle LPE GaN substrate is essential for fabricating on FET structure with a flat surface.
Structural and mechanical properties of dolomite rock under high pressure conditions: A first‐principles study
Authors: Bakri Z. , Zaoui A. 
Published: March 2011

AbstractThe structural behaviour of carbonate minerals under lower mantle pressures, experimentally investigated by means of X‐ray diffraction and infrared spectra measurements can be interpreted and difficulties surmounted by first principles quantum mechanical simulations based on density functional theory (DFT). This work is devoted to structural and mechanical properties of CaMg(CO3)2–dolomite mineral. From Birch–Murnaghan equation of state (BM‐EoS) applied to the energy–volume data of the dolomite polymorph, we obtain a bulk modulus of 93.7 GPa with a pressure derivative of 4.7, which show suitable agreement with experimental data. Under hydrostatic pressure the mineral system shows an anisotropic compression behaviour and is found to be more compressible in the z direction. The investigation of dolomite mineral structural phase stability under hydrostatic pressure has confirmed previously range‐determined but still debated values of structural phase transition. Two phases transitions were encountered when increasing pressure. The first one occurring from dolomite to the orthorhombic calcite‐III‐like structure was predicted at ∼34 GPa; and the second one between the calcite III and the aragonite II at ∼52.5 GPa. This approach overestimates the transition pressure value when confronted to experimental findings. On the other hand the mechanical behaviour of this mineral under ambient and high pressure conditions was studied. To this end we used a stress–strain ab initio based model to calculate the elastic constants of CaMg(CO3)2–dolomite. Based on the trigonal symmetry (space group R3) we found 196.6, 64.4, 54.7, 22.4, 110 and 41.6 GPa for C11, C12, C13, C14, C33 and C44, respectively.
A Tool to Estimate Land‐Surface Emissivities at Microwave frequencies (TELSEM) for use in numerical weather prediction
Authors: Aires Filipe , Prigent Catherine , Bernardo Frédéric , Jiménez Carlos , Saunders Roger , Brunel Pascal 
Published: March 2011

AbstractA Tool to Estimate Land Surface Emissivities at Microwave frequencies (TELSEM) has been developed for use with the Radiative Transfer for the Television and infrared Observation satellite operational Vertical Sounder (RTTOV) model. Its objective is to provide a good estimate of the microwave surface emissivity to improve the retrieval of atmospheric profiles or the direct assimilation of radiances in numerical weather prediction (NWP) models using microwave sounder data over land. TELSEM provides emissivity estimates and error‐covariance matrices for all land surfaces between 19 and 100 GHz and for all angles and linear polarizations. It is based on a pre‐calculated monthly‐mean emissivity climatology derived from Special Sensor Microwave/Imager (SSM/I) observations. Results show that when TELSEM is used, radiative‐transfer simulations are closer to real observations. This is important when RTTOV is used to generate simulated datasets, to analyze new instrument concepts or for assimilation schemes. Experiments also show that TELSEM can be applied to provide a first guess for the surface emissivity down to 6 GHz and up to 190 GHz (extrapolating the SSM/I emissivities). These emissivities are essential for atmospheric profile retrievals over land: results for water‐vapour retrieval show that surface‐contaminated channels can be utilized and that the retrieval is improved, in particular for the lower troposphere. Furthermore, TELSEM emissivity first guesses can be improved in emissivity‐retrieval schemes. Copyright © 2011 Royal Meteorological Society and British Crown Copyright, the Met Office
DFT and Ab Initio calculations of spectroscopic properties of tetramethyltin and of its cation
Authors: Dhouib A. , Abderrabba M. , Essalah K. , Brites V. , Hochlaf M. 
Published: March 2011

AbstractDFT and ab initio calculations are performed on tetramethyltin (SnMe4, TMSn) and its cation. A set of spectroscopic constants for both species are derived. They include equilibrium geometries, rotational constants and vibrational wavenumbers. All quantities are in close agreement with the available experimental data. For the cation, our calculations confirm the C3v charge transfer structure proposed earlier through the analysis of electron paramagnetic resonance (EPR) experimental data. Using multi reference configuration interaction and time dependant density functional theory (TD‐DFT) methodologies, the vertical electronic excitation energies of TMSn and TMSn+ are determined. For the singlet‐singlet neutral molecule, our calculated transition energies are distinctly lower than those previously computed. For the TMSn (
$\tilde X$1A1 → 11T2) absorption transition, our computed excitation energy coincides, however, with the experimental value. Predictive data are also given for the TMSn triplets. At the best level of theory, the vertical and the adiabatic ionization energies of TMSn are computed 9.86 eV and 8.74 eV, respectively. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012