bluuebunny/crossref_metadata_2025_split huggingface dataset:
GPRC6A mediates responses to osteocalcin in β-cells in vitro and pancreas in vivo
Authors: Pi Min , Wu Yunpeng , Quarles L Darryl 
Published: March 2011

Abstract
A bone-pancreas endocrine loop has been identified recently that involves insulin secreted from β-cells in the pancreas stimulating insulin receptors in osteoblasts, leading to osteoblastic differentiation and increased secretion of osteocalcin (Ocn), a bone-derived hormone that regulates insulin secretion in β-cells. The identity of the Ocn-sensing receptor in β-cells is a missing component of this endocrine loop. The abnormalities in glucose homeostasis in Gprc6a null mice suggests that this pertussis toxin–sensitive G protein–coupled receptor is a candidate for mediating the effects of Ocn on insulin secretion in the pancreas. In support of this possibility, we found that transfection of non-Gprc6a-expressing HEK-293 cells with a full-length Gprc6a cDNA imparted a dose-dependent response to Ocn (5 to 60 ng/mL), as measured by PKD1 and ERK phosphorylation. In addition, Gprc6a is highly expressed in mouse pancreatic tissue and in the mouse TC-6 pancreatic β-cell line. Ocn also stimulated ERK activity in TC-6 pancreatic β-cells. Finally, intraperitoneal injection of Ocn stimulated ERK activity in the pancreas and increased serum insulin levels in wild-type mice, but these responses were markedly attenuated in Gprc6a−/− mice. These findings suggest that GPRC6A is a candidate for mediating the response to Ocn in the bone-pancreas endocrine loop regulating insulin signaling. © 2011 American Society for Bone and Mineral Research.
Structural, electronic, bonding, and elastic properties of NH3BH3: A density functional study
Authors: Lingam Ch. Bheema , Babu K. Ramesh , Tewari Surya P. , Vaitheeswaran G. 
Published: March 2011

AbstractThe structural, electronic, bonding, and elastic properties of the low‐temperature orthorhombic phase of NH3BH3 are studied by means of first‐principles total energy calculations based on the pseudopotential method. The calculated structural parameters of NH3BH3 are found to be in good agreement with the experimental values. From the band structure calculations, the compound is found to be an indirect bandgap insulator with the bandgap of 5.65 eV (5.90 eV) with LDA(GGA) along the Γ‐Z direction. The Mulliken bond population and the charge density distributions are used to analyze the chemical bonding in NH3BH3. The study reveals that B–H bonds are more covalent than N–H bonds. The elastic constants are predicted for ambient as well as pressures up to 6 GPa, from which theoretical values of all the related mechanical properties such as bulk modulus, shear modulus, Young's modulus, Poisson's ratio, and anisotropy factors are calculated. It is found that NH3BH3 is mechanically stable at ambient and also external pressures up to 6 GPa. As pressure increases all the calculated elastic moduli of NH3BH3 increase, indicating that the compound becomes more stiffer and hard under pressure. From the ratio of shear modulus to bulk modulus (G/B), we conclude NH3BH3 to be ductile in nature, and the ductility increases with pressure. The present results confirm the experimentally observed less plastic nature of the low‐temperature phase of NH3BH3. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Positive and negative cognitive style correlates of the vulnerability to hypomania
Authors: Dempsey Robert C. , Gooding Patricia A. , Jones Steven H. 
Published: March 2011

AbstractSpecific forms of ruminative cognitive styles and self‐appraisals have been implicated in the development of bipolar symptomatology. This study investigated the associations between measures of positive and negative forms of appraisals and rumination with vulnerability to hypomania, and also investigated the conceptual overlap between these measures in terms of the responses to emotional experiences captured. Hypomania vulnerability was predicted by measures of positive cognitive styles, whilst current depressive symptoms were explained by scores on measures of negative cognitive styles in an analogue sample of 353 participants. A principal components analysis conducted upon the rumination and appraisal measures yielded three components representing positive and negative cognitive styles, and a normalizing of symptoms component. The implications of these results are discussed. © 2011 Wiley Periodicals, Inc. J Clin Psychol 67:673–690, 2011.
Diffusion of benzene and toluene into aqueous nitric acid‐sulphuric acid mixtures
Authors: Hanson Carl , Ismail Hamed A. M. 
Published: March 2011

AbstractDiffusion coefficients of toluene and benzene into aqueous mixtures of nitric and sulphuric acids have been measured at 30°C by use of a laminar jet technique. Equations are presented which correlate the data in terms of the acid concentrations and permit extrapolation to acid mixtures of interest for industrial mononitration reactions. The results show the expected dependence on viscosity of the acid phase and are in agreement with values predicted by the Wilke and Chang correlation.
Studies on the electrosynthesis of organic compounds: II. Reducibility of some Schiff's bases on lead and copper cathodes
Authors: Osman Abdel Megid , El‐Cheikh Fathallah , Khalill Zarif H. , Khodair Ahmed I. 
Published: March 2011

AbstractThe electrochemical reducibility of some Schiff's bases was studied on copper and lead cathodes. The effects of different substituents and the nature of the cathode material on the reduction efficiency of these compounds were investigated. The products of reduction were found to catalyse the reduction process itself leading to an increase of reducibility (reduction efficiency) with time.
Polyol surfactants derived from moringa seed oil for potential use in the pharmaceutical industry
Authors: Sengupta Anupam , Basu Saumyapriya P. 
Published: March 2011

AbstractTwo polyol surfactants ((a) a crude product of 60% monoglyceride content and (b) a homogeneous sorbitan ester) have been prepared by alcoholysis from the not well known edible Moringa concanensis seed oil. These products constituted mainly oleic acid, which will be suitable for utilisation in the pharmaceutical industry. The optimum conditions of glycerolysis of the moringa seed oil have also been found.
Energetics of fungal growth: The effect of growth‐limiting substrate on respiration of Penicillium chrysogenum
Authors: Mason Hugh R. S. , Righelato Renton C. 
Published: March 2011

AbstractIn sucrose‐limited culture of Penicillium chrysogenum the growth yields, corrected for maintenance, for sucrose and oxygen, at dilution rates below 0.05 h−1, were 86 g dry biomass/mol hexose and 39 g dry biomass/mol O2. Similar yields have been observed with other moulds and with yeasts. In oxygen‐limited culture the yield from oxygen was two to three times higher and the yield from sucrose about 10% higher than in sucrose‐limited culture. In phosphate‐limited cultures the respiration rate was unaffected by oxygen concentrations between 0.06 and 0.18 bar and by the concentration of sucrose in the medium between 0.1 m and 0.3 m. The excess of sucrose over the growth requirement was metabolised to organic acids, predominantly malate and gluconate. The results suggest that, in the presence of excess oxygen, the respiration rate is controlled by the biosynthetic demand for energy.
Selection of strains of Penicillium chrysogenum with reduced penicillin yields in continuous cultures
Authors: Righelato Renton C. 
Published: March 2011

AbstractIn sucrose‐limited chemostat cultures of high‐yielding strains of Penicillium chrysogenum the ability to produce penicillin was progressively lost. Subcultures from the chemostats on to agar showed a progressive increase in the proportion of non‐conidiating colonies, designated the D‐phenotype, which produced low yields of penicillin in shake‐flask tests. When the growth‐limiting substrate was ammonia, phosphate or sulphate, production of penicillin was maintained and the D‐phenotype did not appear. However, when a mutant with the D‐phenotype was inoculated into an ammonia‐limited culture of the parent strain, it quickly displaced the parent. The mutant had a yield constant for ammonia 44% higher than had the parent. The conclusion reached is that growth‐limitation by the carbon source is necessary for the occurrence of the mutation or for the initial stages of selection.
Long‐chain alkyl phthalic acids and their derivatives
Authors: Carson Phillip A. , Lapper Mark 
Published: March 2011

AbstractThe synthesis of alkyl phthalic acids by the oxidation of alkyl ortho‐xylenes is described. The evaluation of their derivatives as detergent actives (surfactants), builders (water softeners), fabric‐softeners and as PVC plasticisers is discussed. A brief mention is made of some aspects of their biodegradation.
Isolation of fatty acids from an egyptian petroleum
Authors: Khodair Ahmed I. , Abdel‐Wahab Aboel‐Magd A. 
Published: March 2011

AbstractA mixture of straight‐chain fatty acids (from C7 to C19) was isolated from an Egyptian petroleum via extractive crystallisation with urea. Although the total acidic content in Egyptian petroleum is low, the fatty acids constitute at least 32% of the total acids. n‐Pentadecanoic and n‐nonadecanoic acids were isolated for the first time from petroleum acids by a sequence involving fractional distillation of the methyl esters, extractive crystallisation with urea and recrystallisation of amide derivatives.
Synthesis and study of dyeing properties of some new silicon‐containing anthraquinone dyes
Authors: Metwally Saoud A. M. 
Published: March 2011

AbstractSilicon‐containing dyes based on the 2‐methylanthraquinone chromophore have been prepared by interaction of γ‐aminopropyltriethoxysilane with 2‐(substituted methyl) anthraquinones. These dyes are amorphous glass‐like solids and their possible applications, particularly to glass fibres, have been examined.
Thermal decomposition and pore structure of pure and doped stannic oxide gel
Authors: Mikhail Raouf Sh. , Selim Suzy A. , Zeidan Farouk I. 
Published: March 2011

AbstractThe surface properties of a stannic oxide gel and its thermal dehydration products obtained both in vacuo and in the presence of air in the temperature range 100–600°C have been examined by N2 adsorption. Phase and structural changes have been followed by differential thermal analysis and X‐ray diffractometry. Complete pore structure analysis showed that samples dehydrated at or below 250°C were microporous. Above 250°C the pores were found to widen with increase of temperature, the widening occurring concurrently with the crystallisation process. Doping with cations of lower valency (Li+ and Al3+) than the host cation (Sn4+) had little effect on the pore structure and specific surface area for the low temperature samples (≤250°), whereas at higher temperatures, e.g. 600°C, it increased the specific area remarkably. The dope ions produce oxygen vacancies and hinder or retard sintering in SnO2.
Thermal decomposition of uranium peroxide hydrates
Authors: Sato Taichi 
Published: March 2011

AbstractThe thermal decomposition of uranium peroxide hydrates, UO4·4H2O and UO4·2H2O, has been investigated by thermal analyses, X‐ray diffraction study and infrared spectroscopy. As a result, it is concluded that the thermal decomposition of uranium peroxide hydrates proceeds in the following sequence:magnified imagewhere 3 ≤ x ≤ 3.5.
Analysis of immobilised multi‐enzyme reaction systems with Michaelis‐Menten kinetics
Authors: Ramachandran P. A. , Krishna R. , Panchal C. B. 
Published: March 2011

AbstractThe consecutive sequence of reactions S → P1 → P2 taking place inside a permeable spherical particle is analysed for the case in which the enzyme‐catalysed steps in the reaction follow Michaelis‐Menten type kinetics. The case in which each step in the reaction is inhibited by its product is also considered. The theoretical analysis takes into account both interparticle and intraparticle diffusional limitations and utilises an orthogonal collocation technique to obtain the effectiveness factor and selectivity of the reaction sequence. The orthogonal collocation method is found to be both convenient and simple and the analysis should prove useful in the design of immobilised multi‐enzyme reactors.
Some cultural conditions for the production of puromycin by Streptomyces alboniger
Authors: Shaheen Ahmed B. , Abou‐Zeid Abou‐Zeid A. , El‐Diwany Ahmed I. 
Published: March 2011

AbstractA simple synthetic medium was used in the fermentative production of puromycin to investigate the efficiencies of certain ingredients in stimulating the organism for higher yield. Addition of certain amino acids, especially L‐histidine, L‐glutamic acid, L‐proline, L‐aspartic acid, DL‐methionine, L‐leucine, β‐alanine, L‐isoleucine, DL‐alanine, L‐tyrosine and L‐glycine, increased the antibiotic yield compared with the control. Lactic acid was more suitable for antibiotic production than the other organic acids used, i.e. maleic, acetic, malic, tartaric and fumaric acids. Addition of certain vitamins, namely cobalamin (vitamin B12), nicotinic acid, vitamin B1 and folic acid, did not markedly increase the antibiotic yield. Certain trace elements, such as zinc, copper, iron, manganese and cobalt, played an important role in the biosynthesis of puromycin by Streptomyces alboniger NRRL B‐2403. The optimum concentrations of these trace elements were 0.2000, 0.0020, 0.0005, 0.3000, and 0.0050 g/litre respectively. The optimum concentration of K2HPO4 favouring biosynthesis of puromycin was 1.5 g/litre. The amino acids formed in the microbial cells of Streptomyces alboniger NRRL B‐2403 during the production of puromycin in the synthetic medium were determined quantitatively. Generally, all the amino acids recorded appeared in the microbial cells.
Study of some sulphur‐group solvents for aromatics extraction by gas chromatography
Authors: Rawat Bachan S. , Gulati Indar B. , Mallik Kanai Lal 
Published: March 2011

AbstractNineteen organosulphur solvents have been studied by gas chromatography as potential solvents for the extraction of aromatics. The activity coefficients of nine typical hydrocarbon solutes have been determined in these solvents at three temperatures. From the activity coefficient data, the selectivities of all the solvents have been calculated for benzene with respect to each of the other hydrocarbons in order to screen them for extraction studies. Solvent losses in the g.c. column were also studied.
Kinetics of the reaction of hafnium tetrachloride vapour with solid sodium chloride
Authors: Majumdar Sibnath , Ray Hemshanker S. , Kapur Prakash C. 
Published: March 2011

AbstractThe kinetics of the reaction of hafnium tetrachloride vapour with solid sodium chloride spheres to form sodium hexachlorohafnate have been studied as a function of pressure, temperature and sphere size. The course of the reaction was followed by weight gain measurements in an all‐glass closed system using a quartz spring. Various kinetic models for gas‐solid reactions were tested against the experimental data. Only the Carter‐Valensi kinetic model gave a consistently good fit. Possible reaction mechanisms are discussed in the light of the pressure and temperature dependence of the specific rate constant in the Carter‐Valensi model and in the inert marker experiments.
Impurity deposition from an evaporated solvent and its effect on steel oxidation
Authors: Emsley Alan M. , Hill Malcolm P. 
Published: March 2011

AbstractIt is shown that the evaporation of an organic solvent from a solid surface can result in the concentration of dissolved or suspended impurities at specific sites. Concentric ring patterns of the contaminant, which remain on the surface when evaporation is complete, can be explained by analogy with the spreading of liquid films. Trace hydrocarbon impurities can be concentrated on mild steel surfaces in this way, giving similar ring patterns in the early stages of the oxidation reaction in high pressure carbon dioxide atmospheres. Excessive localised oxidation occurs leading to the early development of oxide nodules.
Infrared measurement of total fatty acids in blood serum
Authors: Quintard Bernadette , Desbals Pierrette , Quintard Pierre 
Published: March 2011

AbstractQuantitative determination of total fatty acids in rabbit blood serum is achieved using the infrared absorption band, associated with the C=0 stretching vibration at 1713 cm−1 (5.84 μm). Different tests are described to show the validity of this method for a wide range of variation in total concentration and in individual percentages of any one fatty acid. The results are treated by statistical methods, and it is found that infrared analysis is five times more sensitive than methods described previously. This accurate technique, which can be applied to other serums has, for example, been applied to disclose a systematic error in the preparation of total fatty acid samples when nitrogen flushing is not used.
A kinetic study of the reaction between terephthalic acid and ethylene oxide at atmospheric pressure
Authors: Bhatia Subhash , Rao M. Gopala , Rao M. Someswara 
Published: March 2011

AbstractThe kinetics of the reaction of terephthalic acid with ethylene oxide, in n‐butanol solvent, catalysed by triethyl amine, were investigated in a semi‐batch reactor under atmospheric conditions. It was found that the reaction occurred in the liquid phase and that mass transfer effects were absent. The reaction was found to be pseudo‐zero order in terephthalic acid and first order in ethylene oxide and in catalyst concentration. The effects of reaction temperature, catalyst concentration, particle size of terephthalic acid, ethylene oxide flow rate, stirrer speed and terephthalic acid to ethylene oxide ratio were studied. Particle size of terephthalic acid, stirrer speed and flow rate of ethylene oxide did not affect the reaction rate. The Arrhenius activation energy of the reaction was found to be between 19.2 and 23.5 kcal/mol.
Copper complexes of some tetra‐ and pentapeptides containing polyfunctional amino acids
Authors: El‐Naggar Ahmed M. , Zaher Mahmoud R. , El‐Salam Abd‐Elmonem Abd 
Published: March 2011

AbstractCopper complexes of some tetra‐ and pentapeptides [(I)‐(VI)] containing lysine and ornithine are spectrophotometrically examined. It is shown that all tetra‐ and pentapeptides form red or reddish violet copper complexes with λmax 515–540 nm, and copper‐peptide ratio 1:1. The results achieved confirmed that the N6‐amino group of the lysine residues or the N5‐amino group of the ornithine residues do not participate in complex formation of tetra‐ and pentapeptides even when lysine or ornithine form the N‐terminal amino acid in the peptide.
Sonographic appearance of the normal appendix in children
Authors: Ozel Alper , Orhan Umut Percem , Akdana Burhan , Disli Cagatay , Erturk Sukru Mehmet , Basak Muzaffer , Karpat Zeki 
Published: March 2011

AbstractPurpose.To determine the visualization rate of the appendix in children without appendicitis and investigate factors affecting it.Methods.Between January 2010 and April 2010, 205 consecutive children (103 boys and 102 girls; mean age: 9 years) without clinical signs of appendicitis were examined by ultrasound (US). The location of appendix was determined. The outer appendiceal diameter with and without compression was measured and the content of the lumen and mural vascularity on color Doppler was determined. The appendix diameter was correlated with age, weight, and height using Pearson correlation. For age, weight, and height, children with a visualized appendix were compared with those in whom the appendix was not visualized using Student's t test.Results.The appendix was visualized in 142 of 205 (69.3%) children. The mean diameters of the appendices without and with compression were 4.2 ± 0.9 mm and 3.5 ± 0.8 mm, respectively, with 53.5% of the appendices in the mid‐pelvic location. Appendiceal lumen was empty in 35.2% of children. Only one appendix showed mural vascularity on color Doppler. There was no correlation between the diameter (compressed or noncompressed) of the appendix and age, weight, or height. Mean ± SD age, weight, and height of the children with a visualized appendix (8.6 ± 0.3 years, 29.9 ± 0.9 kg, 127.7 ± 1.7 cm, respectively) were significantly lower than those in children with a nonvisualized appendix (9.8 ± 0.4 years, 36.0 ± 1.8 kg, 134.7 ± 2.5 cm, respectively) (p < 0.05 for all three parameters).Conclusion.In the majority of the children, the appendix can be visualized with US. Age, weight, and height affect the visualization rate of the normal appendix. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound, 2011
Sonographic appearance of a giant appendicular mucocele
Authors: Attarde Vinod , Patil Parag , Apte Abhang , Barhate Kishor , Gandhe Ashish , Sorte Satish , Hattangadi Namit 
Published: March 2011

AbstractMucocele of the appendix is a rare but well‐known entity. Accurate preoperative diagnosis of this surgically curable entity is very important to prevent intraoperative rupture. With multimodality approach using ultrasound and CT, it has been possible to preoperatively diagnose mucocele of the appendix. We describe the ultrasound and CT findings of a giant appendicular mucocele that led us to the correct preoperative diagnosis. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound 2011;
Novel hybrid analysis method for via structure in microwave multilayer circuits
Authors: Tian Yu , Tong Ling , Li Hailiang 
Published: March 2011

AbstractA novel hybrid analysis method including physical modeling approach is presented for the single complete via structure in this paper. The via structure can be decomposed into two types of different sub‐structures: the interior structure and the exterior structure. The characteristic of the interior structure consisting of the vertical via hole between reference planes is solved using the enhanced quasi‐static method which takes into account the effect of parallel plates. The characteristic of the exterior structure is solved by the improved matrix‐penciled fent method. Then the scattering parameters of the complete via structure can be obtained from the result of the exterior and the interior structure. In order to validate the correctness and the accuracy, the comparison results between the hybrid method and Ansoft's HFSS software are displayed for some microwave multilayer circuits with different layer numbers and different boundary conditions. Copyright © 2011 John Wiley & Sons, Ltd.
A circuit model of an ultra wideband impulse radar system for breath‐activity monitoring
Authors: Pisa Stefano , Bernardi Paolo , Cavagnaro Marta , Pittella Erika , Piuzzi Emanuele 
Published: March 2011

SUMMARYThe aim of this work is to present a circuit model to analyze and design ultra wideband (UWB) radars for the remote monitoring of breath activity. The model includes the impulse signal source, the transceiver antenna, the transmission medium, and the human thorax. First of all, the proposed model has been validated by comparing its responses with those achieved both numerically, with a commercial electromagnetic modeling software, and experimentally, by means of a setup based on an indirect time domain reflectometry system. Then, the model has been used for analyzing the feasibility of a UWB radar operating in the 3–6‐GHz range with an effective isotropic radiated power lower than − 41.3 dBm/MHz, i.e. within the limits issued by the United States Federal Communications Commission for unlicensed UWB imaging systems. The model outlined the possibility of the considered UWB radar of monitoring the breath activity of a subject up to distances of about 10 m in open air. Copyright © 2011 John Wiley & Sons, Ltd.