bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics of radical polymerization of glycidyl methacrylate initiated by multi‐site phase transfer catalyst–potassium peroxydisulfate in two‐phase system
Authors: Vajjiravel Murugesan , Umapathy M. J. 
Published: December 2010

AbstractThe kinetics of radical polymerization of glycidyl methacrylate, initiated by the free radicals formed in situ in the multi‐site phase transfer catalyst (PTC), 1,1,2,2‐tetramethyl‐1‐benzyl‐2‐n‐propylethylene‐1,2‐diammonium bromide chloride–potassium peroxydisulfate system was studied in an aqueous–organic two‐phase media at 60°C ± 1°C under inert and unstirred condition. The rate of polymerization (Rp) was determined at various concentrations of the monomer, initiator, catalyst, and volume fraction of aqueous phase. The effect of acid, ionic strength, and water‐immiscible organic solvents on the Rp was examined. The temperature dependence of the rate was studied, and activation parameters were calculated. Rp increased with an increase in the concentrations of monomer, initiator, multi‐site PTC, and increase in the polarity of solvent and temperature. The order with respect to monomer, initiator, and multi‐site PTC was found to be 0.50. A feasible free‐radical mechanism consistent with the experimental data has been proposed, and its significance was discussed. The synthesized polymer was confirmed by Fourier transform infrared spectral analysis. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Cloning and expression analysis of a G‐protein subunit— in the rice water weevillissorhoptrus oryzophilusKuschel
Authors: Kang Gui‐Juan , Gong Zhong‐Jun , Cheng Jia‐An , Mao Cun‐Gui , Zhu Zeng‐Rong 
Published: December 2010

AbstractThe open reading frame (ORF) encoding a novel G proteinαsubunit, Lo Gαo, was cloned from the parthenogenetic rice water weevil,Lissorhoptrus oryzophilusKuschel (Coleoptera: Curculionidae). The Lo GαoORF encodes a protein of 354 amino acid residues. The deduced protein sequence shares high homology with Gαofrom other species. The expression patterns of Lo Gαoin various adult tissues were indicated by real‐time quantitative PCR and Western blot. The results showed that Lo GαomRNA was expressed at similar levels in tissues except relative high levels in the antennae of adult, and Lo Gαoprotein of an apparent molecular mass of about 40 kDa was expressed in various tissues of the adult. Immunocytochemical localization showed that Lo Gαowas mainly expressed in the dendrites of the trichoid sensilla in the antenna of the weevil. The tissue and cellular localization of Lo Gαosuggests that Lo Gαomay take a part in signal transduction of olfactory/gustatory. © 2010 Wiley Periodicals, Inc.
Further Considerations on the Theory of Aging (Ostwald Ripening)
Authors: Kahlweit M. 
Published: December 2010

AbstractThe present theory of Ostwald ripening predicts that the aging rate of a precipitate as well as the shape of its size distribution asymptotically approach a stationary state. These predictions have to be corrected insofar as it is not an asymptotical approach, but instead a quasistationary behavior during a limited time interval of the precipitation. This range of validity depends strongly on the kinetics of the precipitation, i.e. on the initial size distribution and the growth mechanism.
Interdiffusion of aqueous silver nitrate and potassium chromate and the periodic precipitation of silver chromate Liesegang bands
Authors: Curtis Nicolette , Leaist Derek G. 
Published: November 2010

AbstractPeriodic bands of crystals (Liesegang rings) are formed when a pair of soluble salts interdiffuses and reacts to form an insoluble salt. A classic example is the banded precipitation of silver chromate produced by the interdiffusion of aqueous silver nitrate and potassium chromate: 2AgNO3(aq)+K2CrO4(aq) = Ag2CrO4(s)+2KNO3(aq). This process is studied by using Taylor dispersion to measure interdiffusion coefficients, including cross‐coefficients, for aqueous AgNO3+KNO3 and K2CrO4+KNO3 solutions found on opposite sides of AgNO3/K2CrO4 diffusion boundaries. Silver chromate readily supersaturates to 5 times its solubility. This information together with the measured diffusion coefficients and previously reported rates of precipitation are used to develop a diffusion‐precipitation model for the formation of silver chromate Liesegang rings. Numerical integration of the equations employing a Gaussian distribution of critical supersaturation values shows that a sharp supersaturation limit is not essential for periodic precipitation, and secondary band structure is predicted.
Association of retinoic acid receptor genes with meningomyelocele
Authors: Tran Phong X. , Au Kit Sing , Morrison Alanna C. , Fletcher Jack M. , Ostermaier Kathryn K. , Tyerman Gayle H. , Northrup Hope 
Published: December 2010

AbstractBACKGROUNDNeural tube defects (NTDs) occur in as many as 0.5–2 per 1000 live births in the United States. One of the most common and severe neural tube defects is meningomyelocele (MM) resulting from failed closure of the caudal end of the neural tube. MM has been induced by retinoic acid teratogenicity in rodent models. We hypothesized that genetic variants influencing retinoic acid (RA) induction via retinoic acid receptors (RARs) may be associated with risk for MM.METHODSWe analyzed 47 single nucleotide polymorphisms (SNPs) that span across the three retinoic acid receptor genes using the SNPlex genotyping platform. Our cohort consisted of 610 MM families.RESULTSOne variant in the RARA gene (rs12051734), three variants in the RARB gene (rs6799734, rs12630816, rs17016462), and a single variant in the RARG gene (rs3741434) were found to be statistically significant at p < 0.05.CONCLUSIONRAR genes were associated with risk for MM. For all associated SNPs, the rare allele conferred a protective effect for MM susceptibility. Birth Defects Research (Part A), 2011. © 2010 Wiley‐Liss, Inc.
Statistical perturbations in personal exposure meters caused by the human body in dynamic outdoor environments
Authors: Rodríguez Begoña , Blas Juan , Lorenzo Rubén M. , Fernández Patricia , Abril Evaristo J. 
Published: November 2010

AbstractPersonal exposure meters (PEM) are routinely used for the exposure assessment to radio frequency electric or magnetic fields. However, their readings are subject to errors associated with perturbations of the fields caused by the presence of the human body. This paper presents a novel analysis method for the characterization of this effect. Using ray‐tracing techniques, PEM measurements have been emulated, with and without an approximation of this shadowing effect. In particular, the Global System for Mobile Communication mobile phone frequency band was chosen for its ubiquity and, specifically, we considered the case where the subject is walking outdoors in a relatively open area. These simulations have been contrasted with real PEM measurements in a 35‐min walk. Results show a good agreement in terms of root mean square error and E‐field cumulative distribution function (CDF), with a significant improvement when the shadowing effect is taken into account. In particular, the Kolmogorov–Smirnov (KS) test provides a P‐value of 0.05 when considering the shadowing effect, versus a P‐value of 10−14 when this effect is ignored. In addition, although the E‐field levels in the absence of a human body have been found to follow a Nakagami distribution, a lognormal distribution fits the statistics of the PEM values better than the Nakagami distribution. As a conclusion, although the mean could be adjusted by using correction factors, there are also other changes in the CDF that require particular attention due to the shadowing effect because they might lead to a systematic error. Bioelectromagnetics 32:209–217, 2011. © 2010 Wiley‐Liss, Inc.
Germline stem cell maintenance as a proximate mechanism of life‐history trade‐offs?
Authors: Kaczmarczyk Angela N. , Kopp Artyom 
Published: November 2010

AbstractWe suggest that the commonly observed trade‐offs between early‐ and late‐life reproduction may be mediated by genetic variation in germline stem cell maintenance. Stem cell biology provides a natural framework and experimental methods for understanding the mechanistic basis of life‐history evolution. At the same time, natural variation in life‐history strategies can serve as a powerful tool for identifying the genes and molecular pathways involved in the maintenance of stem cells in aging adults. We illustrate the connections between life‐history and stem cells with examples drawn primarily from Drosophila melanogaster and Caenorhabditis elegans, and suggest a number of testable hypotheses and avenues for future investigation that can be addressed with existing models and tools.
Improving N‐glycosylation efficiency in Escherichia coli using shotgun proteomics, metabolic network analysis, and selective reaction monitoring
Authors: Pandhal Jagroop , Ow Saw Yen , Noirel Josselin , Wright Phillip C. 
Published: December 2010

AbstractRecently, the prospect of using Escherichia coli as a host for human glycoprotein production has increased due to detailed characterization of the prokaryotic N‐glycosylation process and the ability to transfer the system into this bacterium. Although functionality of the native Campylobacter jejuni N‐glycosylation system in E. coli has been demonstrated, the efficiency of the process using the well‐characterized C. jejuni glycoprotein AcrA, was found to be low at 13.4 ± 0.9% of total extracted protein. A combined approach using isobaric labeling of peptides and probability‐based network analysis of metabolic changes was applied to forward engineer E. coli to improve glycosylation efficiency of AcrA. Enhancing flux through the glyoxylate cycle was identified as a potential metabolic manipulation to improve modification efficiency and was achieved by increasing the expression of isocitrate lyase. While the overall recombinant protein titre did not change significantly, the amount of glycosylated protein increased by approximately 300%. Biotechnol. Bioeng. 2011; 108:902–912. © 2010 Wiley Periodicals, Inc.
Processing/structure/property relationship of multi‐scaled PCL and PCL–HA composite scaffolds prepared via gas foaming and NaCl reverse templating
Authors: Salerno A. , Zeppetelli S. , Di Maio E. , Iannace S. , Netti P.A. 
Published: December 2010

AbstractIn this study, we investigated the processing/structure/property relationship of multi‐scaled porous biodegradable scaffolds prepared by combining the gas foaming and NaCl reverse templating techniques. Poly(ε‐caprolactone) (PCL), hydroxyapatite (HA) nano‐particles and NaCl micro‐particles were melt‐mixed by selecting different compositions and subsequently gas foamed by a pressure‐quench method. The NaCl micro‐particles were finally removed from the foamed systems in order to allow for the achievement of the multi‐scaled scaffold pore structure. The control of the micro‐structural properties of the scaffolds was obtained by the optimal combination of the NaCl templating concentration and the composition of the CO2–N2 mixture as the blowing agent. In particular, these parameters were accurately selected to allow for the fabrication of PCL and PCL–HA composite scaffolds with multi‐scaled open pore structures. Finally, the biocompatibility of the scaffolds has been assessed by cultivating pre‐osteoblast MG63 cells in vitro, thus demonstrating their potential applications for bone regeneration. Biotechnol. Bioeng. 2011; 108:963–976. © 2010 Wiley Periodicals, Inc.
Real time monitoring of multiple parameters in mammalian cell culture bioreactors using an in‐line Raman spectroscopy probe
Authors: Abu‐Absi Nicholas R. , Kenty Brian M. , Cuellar Maryann Ehly , Borys Michael C. , Sakhamuri Sivakesava , Strachan David J. , Hausladen Michael C. , Li Zheng Jian 
Published: December 2010

AbstractThe FDA's process analytical technology initiative encourages drug manufacturers to apply innovative ideas to better understand their processes. There are many challenges to applying these techniques to monitor mammalian cell culture bioreactors for biologics manufacturing. These include the ability to monitor multiple components in complex medium formulations non‐invasively and in‐line. We report results that demonstrate, for the first time, the technical feasibility of the in‐line application of Raman spectroscopy for monitoring a mammalian cell culture bioreactor. A Raman probe was used for the simultaneous prediction of culture parameters including glutamine, glutamate, glucose, lactate, ammonium, viable cell density, and total cell density. Bioeng. 2011; 108:1215–1221. © 2010 Wiley Periodicals, Inc.
Systematic review of the effect of external beam radiation therapy to the breast on axillary recurrence after negative sentinel lymph node biopsy
Authors: van Wely B J , Teerenstra S , Schinagl D A X , Aufenacker T J , de Wilt J H W , Strobbe L J A 
Published: November 2010

Abstract

Background
Axillary recurrence after negative sentinel lymph node biopsy (SLNB) in patients with invasive breast carcinoma remains a concern. Previous investigations to identify prognostic factors for axillary recurrence identified that a disproportionate number of patients with an axillary recurrence after negative SLNB were not treated with external beam radiation therapy (EBRT) of the breast as part of initial treatment. This finding prompted a systematic review to test the hypothesis that EBRT to the breast reduces the risk of axillary recurrence after negative SLNB.

Methods
A literature search was performed in PubMed, the Cochrane Library and the Spanish-language database LILACS to identify articles publishing data regarding follow-up of sentinel lymph node (SLN)-negative patients. Reports and articles lacking information on the initial treatment were excluded.

Results
Forty-five articles were accepted for review. A total of 23 357 SLN-negative patients were identified with median follow-up ranging from 15 to 102 months. Some 18 878 patients were treated with EBRT to the breast as part of their initial treatment. One hundred and twenty-seven patients with an axillary recurrence were identified, of whom 73 had EBRT as part of their initial treatment. Meta-analysis showed that EBRT was associated with a lower rate of axillary recurrence (P &lt; 0·001), but this finding was subject to heterogeneity.

Conclusion
This review and meta-analysis showed that EBRT is associated with a significantly lower axillary recurrence rate after negative SLNB.
A lesson plan for the enhancement of training and research in academia by the adaptation and adoption of good laboratory practice guidelines
Authors: Sitaraman Ramakrishnan 
Published: November 2010

AbstractThe implementation of good laboratory practices (GLPs) is recognized by the biotechnology and pharmaceutical industries as being critical for ensuring the international acceptability of products. However, as universities and colleges (and research organizations) do not necessarily work under similar constraints, actual laboratory practices vary widely, and students (or employees) are not required to have any exposure to GLP standards and stipulations. This essay makes a case for formally introducing principal investigators, students, and other laboratory personnel to the GLP regime. Many of these practices, while not absolutely required in academic laboratories, could nevertheless facilitate smooth and efficient running of the laboratory and also equip students with the knowledge and experience necessary for a facile transition to an industrial setting. Biochemistry and Molecular Biology Education Vol. 38, No. 6, pp. 365‐369, 2010
Optical biosensing: Kinetics of protein A‐IGG binding using biolayer interferometry
Authors: Wilson Jo Leanna , Scott Israel M. , McMurry Jonathan L. 
Published: November 2010

AbstractAn undergraduate biochemistry laboratory experiment has been developed using biolayer interferometry (BLI), an optical biosensing technique similar to surface plasmon resonance (SPR), in which students obtain and analyze kinetic data for a protein‐protein interaction. Optical biosensing is a technique of choice to determine kinetic and affinity constants for biomolecular interactions. Measurements can be made in real‐time without labels, making biosensing particularly appropriate for the teaching laboratory. In the described exercise, students investigate the kinetics of Protein A‐human Immunoglobin G binding under conditions that mimic simple 1:1 binding. Students prepare appropriate serial dilutions of IgG and set up a microplate for the experiment by aliquotting biotinylated Protein A, buffer, and IgG solutions. A commercial BLI sensor, the FortéBio Octet QK, is used to measure binding. While data are collected students prepare a spreadsheet with which they will simulate the data to determine kon, koff, and KD. Raw data from the sensor are then exported to the spreadsheets for analysis. Optimized experiment timing, regeneration methods and other parameters are described to increase throughput and reduce cost. The experiment is readily adaptable to other biosensing platforms such as SPR instruments. Biochemistry and Molecular Biology Education Vol. 38, No. 6, pp. 400‐407, 2010
Effects of IMAC specific peptide tags on the stability of recombinant green fluorescent protein
Authors: Widakowich Gabriel , Zhang Chunfang , Harris Simon , Mitri Khosse , Powers Glenn , Troung Kirk‐Ski , Hearn Milton T W 
Published: November 2010

AbstractImmobilized metal ion affinity chromatography (IMAC) using peptide affinity tags has become a popular tool for protein purification. An important feature dictating the use of a specific affinity tag is whether its structure influences the properties of the target protein to which it is attached. In this work we have studied the influence on protein stability of two novel peptide affinity tags, namely NT1A and HIT2, and compared their effect to the commonly used hexa‐histidine tag, all attached to the C‐terminus of a enhanced green fluorescent protein (eGFP). A comparison of the influence of C‐ or N‐terminal orientation of the tags was also carried out by studying the NT1A tag attached at either terminus of the eGFP. Protein stability was studied utilising guanidine hydrochloride equilibrium unfolding procedures and CD and fluorescence spectroscopy. The novel peptide affinity tags, NT1A and HIT2, and the His6 tag were found to not affect the stability of eGFP. Although these results are protein specific, they highlight, nevertheless, the need to employ suitable characterisation tools if the impact of a specific peptide tag on the folded status or stability of a recombinant tagged protein, purified by immobilized metal ion affinity chromatographic methods, are to be rigorously evaluated and the appropriate choice of peptide tag made. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Historical vignettes of the thyroid gland
Authors: Lydiatt Daniel D. , Bucher Gregory S. 
Published: November 2010

AbstractAlthough “glands” in the neck corresponding to the thyroid were known for thousands of years, they were mainly considered pathological when encountered. Recognition of the thyroid gland as an anatomical and physiological entity required human dissection, which began in earnest in the 16th century. Leonardo Da Vinci is generally credited as the first to draw the thyroid gland as an anatomical organ. The drawings were subsequently “lost” to medicine for nearly 260 years. The drawings were probably of a nonhuman specimen. Da Vinci vowed to produce an anatomical atlas, but it was never completed. Michelangelo Buonarroti promised to complete drawings for the anatomical work of Realdus Columbus, De Re Anatomica, but these were also never completed. Andreas Vesalius established the thyroid gland as an anatomical organ with his description and drawings in the Fabrica. The thyroid was still depicted in a nonhuman form during this time. The copper etchings of Bartholomew Eustachius made in the 1560s were obviously of humans, but were not actually published until 1714 with a description by Johannes Maria Lancisius. These etchings also depicted some interesting anatomy, which we describe. The Adenographia by Thomas Wharton in 1656 named the thyroid gland for the first time and more fully described it. The book also attempted to assign a function to the gland. The thyroid gland's interesting history thus touches a number of famous men from diverse backgrounds. Clin. Anat. 24:1–9, 2011. © 2010 Wiley‐Liss, Inc.
H2‐Induced Reconstruction of Supported Pt Clusters: Metal–Support Interaction versus Surface Hydride
Authors: Mager‐Maury Christophe , Bonnard Gaëtan , Chizallet Céline , Sautet Philippe , Raybaud Pascal 
Published: December 2010

AbstractPlatinum nanoparticles supported on γ‐alumina are widely used as highly dispersed heterogeneous catalysts, in particular in the presence of H2. In the present work, an atomic‐scale model for such catalysts is provided, taking into account operating conditions (temperature, hydrogen pressure), thanks to density functional theory calculations coupled to a thermodynamic model. In the absence of hydrogen, Pt13 clusters supported on γ‐Al2O3 preferentially lie in a biplanar (BP) morphology in strong interaction with the support’s surface. This structure has a strong affinity towards hydrogen. The increase of hydrogen coverage above 18 H atoms per cluster (H/Pt>1.4) induces a reconstruction from a BP to a cuboctahedral (CUB) morphology as shown by molecular dynamics. This reconstruction is driven by the ability of the CUB structure to adsorb a significant amount of hydrogen with moderate deformation cost. Electronic analyses reveal that a hydride phase is then obtained, with a partial loss of the metallic nature of the Pt13 edifice. Our model is supported by numerous experimental data (temperature‐programmed desorption, titration experiments, X‐ray absorption spectroscopy). Values higher than 1 for the H/Pt ratio, as measured in previous experimental analyses, are rationalized by the reconstruction process. Moreover, in reaction conditions such as catalytic reforming, the particle remains biplanar with moderate H/Pt ratio and retains its metallic character. The catalytic conditions therefore have a drastic influence on the nature of the catalyst surface.
Hydrogen Peroxide Decomposition over Nanosized La1–XCaXMnO3 (0 ≤ X ≤ 0.6) Perovskite Oxides
Authors: Soleymani M. , Moheb A. , Babakhani D. 
Published: November 2010

AbstractLa1–XCaXMnO3 (X = 0.0, 0.2, 0.4, and 0.6) perovskite oxides were synthesized using the citrate gel method. Thermogravimetry and differential thermal analyses, x‐ray diffraction, scanning electron microscopy, and specific surface area results were used for characterization of the perovskite powders obtained. Also, the average manganese valence state and δ‐oxygen non‐stoichiometry in series compounds were determined by the chemical analysis. Catalytic activities of these perovskites were examined for the peroxide decomposition reaction. It was observed that the catalytic activity was improved with increasing calcium content in the catalyst and it is suggested that factors such as δ‐oxygen non‐stoichiometry and average manganese valence state were responsible for the catalytic activity of these materials.
Synthesis and Thermal Energy Storage Properties of Erythritol Tetrastearate and Erythritol Tetrapalmitate
Authors: Sari A. , Eroglu R. , Biçer A. , Karaipekli A. 
Published: November 2010

AbstractErythritol tetrapalmitate (ETP) and erythritol tetrastearate (ETS) were synthesized as novel solid‐liquid phase change materials (PCM) by means of the direct esterification reaction of the erythritol with palmitic and stearic acids. The ETP and ETS esters were characterized chemically using FT‐IR and 1H NMR techniques. The energy storage properties of the esters were determined by DSC analysis. The results indicated that the ETP and ETS esters synthesized as novel solid‐liquid PCMs are promising materials for thermal energy storage applications at large scale such as solar energy storage, building heating or cooling, indoor temperature controlling, and production of smart textile and insulation clothing.