bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal, dielectric, and mechanical properties of SiC particles filled linear low‐density polyethylene composites
Authors: Zhou Wenying , Yu Demei , Min Chao , Fu Yinping , Guo Xiusheng 
Published: February 2009

AbstractA thermally conductive linear low‐density polyethylene (LLDPE) composite with silicon carbide (SiC) as filler was prepared in a heat press molding. The SiC particles distributions were found to be rather uniform in matrix at both low and high filler content due to a powder mixing process employed. Differential scanning calorimeter results indicated that the SiC filler decreases the degree of crystallinity of LLDPE, and has no obvious influence on the melting temperature of LLDPE. Experimental results demonstrated that the LLDPE composites displays a high thermal conductivity of 1.48 Wm−1 K−1 and improved thermal stability at 55 wt % SiC content as compared to pure LLDPE. The surface treatment of SiC particles has a beneficial effect on improving the thermal conductivity. The dielectric constant and loss increased with SiC content, however, they still remained at relatively low levels (<102 Hz); whereas, the composites showed poorer mechanical properties as compared to pure LLDPE. In addition, combined use of small amount of alumina short fiber and SiC gave rise to improved overall properties of LLDPE composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of some polyacrylate/montmorillonite nanocomposites by in situ emulsion polymerization using redox initiation system
Authors: Effenberger F. , Schweizer M. , Mohamed W. S. 
Published: February 2009

AbstractIntercalated modification of Montmorillonite clay (MMT) with three different amino acids—Alanine, Leucine, and Phenylalanine—in the presence of hydrochloric acid followed by surface modification by methyl triethoxy silane coupling agent to produce double modified Montmorillonite clay which is characterized by X‐ray diffraction (XRD) and Thermogravimetric analysis (TGA). The data shows an increase in d‐spacing of modified clay as a result of cationic exchange. Double modified MMT clay was used in the preparation of Polyacrylate/clay nanocomposites by using an in situ redox emulsion polymerization of polyglycidylmethacrylate (PGMA) and polymethylmethacrylate (PMMA). The structure and properties of the prepared nanocomposites were achieved by XRD, TGA, and SEM. The results show that all weight loses temperatures for the nanocomposite samples are higher than that of pure polymer in both PGMA and PMMA. It is also obvious that the increasing in the clay content plays an effective role in the increasing of thermal stability of these materials. SEM shows that the clay is more homogenously dispersed in PMMA than in PGMA matrix. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The effect of polymer surface modification via interfacial polymerization on polymer–protein interaction
Authors: Liu Sean X. , Kim Jun‐Tae , Kim Sanghoon , Singh Mukti 
Published: February 2009

AbstractMembrane separation is an important processing technology used for separating food ingredients and fractionating value‐added components from food processing byproducts. Long‐term performance of polymeric membranes in food protein processing is impeded by the formation of fouled layers on the membrane surface as a result of protein adsorption onto the membrane surface. Surface modification of synthetic membranes, i.e., changing surface characteristics to reduce protein adsorption permanently, is one of the innovative ways of reducing the fouling of membrane surfaces. In this study, surface modification of flat‐sheet ultrafiltration membrane, polyethersulfone (PES), was investigated in improving the hydrophilicity of PES surfaces, thereby reducing adsorption of the protein caused by hydrophobic–hydrophobic interaction between the protein and the membrane. Hydrophilic polymer grafting through thin‐film composite using interfacial polymerization was employed to improve the hydrophilicity of the commercial PES membranes. Poly(vinyl alcohol), poly(ethylene glycol), and chitosan were chosen as hydrophilic polymers to graft on PES membrane because of their excellent hydrophilic property. Modified PES membranes were characterized by contact angle, FTIR, XPS, and AFM. Contact angles of modified PES membranes were reduced by 25 to 40% of that of the virgin PES membrane. XPS spectrum supported that the PES membranes were successfully modified by interfacial polymerization. Tapping‐mode AFM was used to examine the changes in surface topography of modified PES membranes. The PES membranes modified by interfacial polymerization showed lower roughness (from 1.2 to 2.0 nm) than that of virgin PES membrane (2.1 nm). The results of these instrumental analyses indicated that the PES membranes were successfully enhanced hydrophilically through interfacial polymerization. The protein adsorption on the modified membranes was reduced by 30 to 35% as a result of surface modification of the PES membranes using interfacial polymerization technique. Published 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Regulation of targeted gene repair by intrinsic cellular processes
Authors: Engstrom Julia U. , Suzuki Takayuki , Kmiec Eric B. 
Published: February 2009

AbstractTargeted gene alteration (TGA) is a strategy for correcting single base mutations in the DNA of human cells that cause inherited disorders. TGA aims to reverse a phenotype by repairing the mutant base within the chromosome itself, avoiding the introduction of exogenous genes. The process of how to accurately repair a genetic mutation is elucidated through the use of single‐stranded DNA oligonucleotides (ODNs) that can enter the cell and migrate to the nucleus. These specifically designed ODNs hybridize to the target sequence and act as a beacon for nucleotide exchange. The key to this reaction is the frequency with which the base is corrected; this will determine whether the approach becomes clinically relevant or not. Over the course of the last five years, workers have been uncovering the role played by the cells in regulating the gene repair process. In this essay, we discuss how the impact of the cell on TGA has evolved through the years and illustrate ways that inherent cellular pathways could be used to enhance TGA activity. We also describe the cost to cell metabolism and survival when certain processes are altered to achieve a higher frequency of repair.
Commitment to meiosis: what determines the mode of division in budding yeast?
Authors: Simchen Giora 
Published: February 2009

AbstractIn budding yeast, commitment to meiosis is attained when meiotic cells cannot return to the mitotic cell cycle even if the triggering cue (nutrients deprivation) is withdrawn. Commitment is arrived at gradually, and different aspects of meiosis may be committed at different times. Cells become fully committed to meiosis at the end of Prophase I, long after DNA replication and just before the first meiotic division (MI). Whole‐genome gene expression analysis has shown that committed cells have a distinct and rapid response to nutrients, and are not simply insulated from environmental signals. Thus becoming committed to meiosis is an active process. The cellular event most likely to be associated with commitment to meiosis is the separation of the duplicated spindle‐pole bodies (SPBs) and the formation of the spindle. Commitment to the mitotic cell cycle is also associated with the separation of SPBs, although it occurs in G1, before DNA replication.
Dehalogenation of gaseous 1‐chlorobutane by dehydrated whole cells: Influence of the microenvironment of the halidohydrolase on the stability of the biocatalyst
Authors: Marchand P. , Lamare S. , Legoy M.‐D. , Goubet I. 
Published: February 2009

AbstractIt was observed that a biocatalyst prepared from dehydrated whole cells of a recombinant Escherichia coli (initially suspended in borate buffer) was able to hydrolyze gaseous 1‐chlorobutane in a solid/gas reactor. Nevertheless, at 40°C and for a 0.7 water activity, it rapidly lost its activity. The explanation of this phenomenon was first investigated by observing the biocatalyst structure at the microscopic level and by studying the localization of the dehalogenase involved in catalysis (intracellular/ extracellular). The behavior of this biocatalyst was then compared with that of a preparation made from cells extracts. The reasons of the inactivation are discussed in terms of thermal denaturation and protective effect of buffer salts. Biotechnol. Bioeng. 2009;103: 687–695. © 2009 Wiley Periodicals, Inc.
Cloning, expression and characterization of endo‐β‐1,4‐mannanase from Aspergillus fumigatus in Aspergillus sojae and Pichia pastoris
Authors: Duruksu Gökhan , Ozturk Bengu , Biely Peter , Bakir Ufuk , Ogel Zumrut B. 
Published: February 2009

AbstractTo be utilized in biomass conversion, including ethanol production and galactosylated oligosaccharide synthesis, namely prebiotics, the gene of extracellular endo‐β‐1,4‐mannanase (EC 3.2.1.78) of Aspergillus fumigatus IMI 385708 (formerly known as Thermomyces lanuginosus IMI 158749) was expressed first in Aspergillus sojae and then in Pichia pastoris under the control of the glyceraldehyde triphosphate dehydrogenase (gpdA) and the alcohol oxidase (AOX1) promoters, respectively. The highest production of mannanase (352 U mL−1) in A. sojae was observed after 6 days of cultivation. In P. pastoris, the highest mannanase production was observed 10 h after induction with methanol (61 U mL−1). The fold increase in mannanase production was estimated as ∼12‐fold and ∼2‐fold in A. sojae and P. pastoris, respectively, when compared with A. fumigatus. Both recombinant enzymes showed molecular mass of about 60 kDa and similar specific activities (∼350 U mg−1 protein). Temperature optima were at 60°C and 45°C, and maximum activity was at pH 4.5 and 5.2 for A. sojae and P. pastoris, respectively. The enzyme from P. pastoris was more stable retaining most of the activity up to 50°C, whereas the enzyme from A. sojae rapidly lost activity above 40°C. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Actinomycetes scale‐up for the production of the antibacterial, nocathiacin
Authors: Junker Beth , Walker Andre , Hesse Michelle , Lester Mike , Christensen Jens , Connors Neal 
Published: February 2009

AbstractAn Amycolatopsis fastidiosa culture, which produces the nocathiacin class of antibacterial compounds, was scaled up to the 15,000 L working volume. Lower volume pilot fermentations (600, 900, and 1,500 L scale) were conducted to determine process feasibility at the 15,000 L scale. The effects of inoculum volume, impeller tip speed, volumetric gas flow rate, superficial gas velocity, backpressure, and sterilization heat stress were examined to determine optimal scale‐up operating conditions. Inoculum volume (6 vs. 2 vol %) and medium sterilization (Ro of 68 vs. 92 min−1) had no effect on productivity or titer, and higher impeller tip speeds (2.1 vs. 2.9 m/s) had a slight effect (20% decrease). In contrast, higher backpressure, incorporating increased head pressure at the 15,000 L scale (1.2 vs. 0.7 kg/cm2) and low gas flow rates (0.25 vs. 0.8 vvm), appeared to be problematic (40–50% decrease). High off‐gas CO2 levels were likely reasons for observed lower productivity. Consequently, air flow rate for this 25‐fold scale‐up (600–15,000 L) was controlled to match off‐gas CO2 profiles of acceptable smaller scale batches to maintain levels below 0.5%. The 15,000 L‐scale fermentation achieved an expected nocathiacin I titer of 310 mg/L after 7 days. Other on‐line data (i.e., pH, oxygen uptake rate, and CO2 evolution rate) and off‐line data (i.e., analog production, glucose utilization, ammonium production, and dry cell weight) at the 15,000 L scale also tracked similarly to the smaller scale, demonstrating successful fermentation scale‐up. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
A methodology to learn designing optimal mechanisms for path generation
Authors: Galan‐Marin Gloria , Alonso‐Sanchez F. Javier , Del Castillo‐Granados Jose M. 
Published: February 2009

AbstractThe study of four‐bar linkages to trace a desired path is an important part of teaching in mechanical design. When the number of precision points exceeds a certain number, most recent approaches utilize intelligent optimization methods based on too complex computer science theories to be implemented by an engineering student. In this article we develop and implement new mechanism design results, reducing simultaneously the design space to facilitate finding the optimal mechanism. Finally, we apply global optimization methods that do not require analytical expression of the objective function and are freely available for educational use with Matlab. The proposed computerized methodology focuses student motivation on the mechanical aspects of the problem. Design examples presented illustrate the effectiveness of the approach that provides a solution quality comparable to that of the recently proposed intelligent optimization methods with simplicity of implementation and fast convergence. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 87–92, 2010; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20181
A tool for the educational study of manufacturing systems
Authors: Martínez María A. , Cañadas Mario 
Published: February 2009

AbstractIn this article, a new application for teaching manufacturing systems is presented. A manufacturing system can be considered as a discrete‐event system constructed from devices that have a finite speed of operation. This application automatically simulates the manufacturing systems modelled by timed and stochastic Petri nets (PNs) with additional extensions that easily make possible to get specific information. The graphical model generated provides the necessary data to execute an event‐driven language programme that simulates the model and provides results. From the student's point of view, the problem is only to draw the PN accordingly with the characteristics of the system to be modelled and to get the information without noticing the underlying event‐driven language programme. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 130–143, 2010; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20189
Leptin transport in the central nervous system
Authors: Ziylan Yusuf Ziya , Baltaci Abdulkerim Kasim , Mogulkoc Rasim 
Published: February 2009

AbstractSynthesized and released by the adipose tissue, leptin is the widely studied 167‐amino acid hormonal protein product of the obesity gene. Originally leptin was defined in association with satiety and energy balance and claimed to be an anti‐obesity factor that functioned via a feedback effect from adipocytes to hypothalamus. There is a growing body of evidence that emphasizes the importance of leptin in the regulation of food intake and body weight in animals and humans, alike. Other research findings point out that it plays a role in the regulation of the metabolism, sexual development, reproduction, hematopoiesis, immunity, gastrointestinal functions, sympathetic activation, and angiogenesis. The aim of this review is to evaluate the relation between leptin and the central nervous system (CNS). Copyright © 2009 John Wiley & Sons, Ltd.
Re‐access complication with a starclose device
Authors: Varghese Rekhi , Chess David , Lasorda David 
Published: February 2009

AbstractDiagnostic cardiac catheterizations are predominantly performed using access through the femoral artery. To improve patient comfort and early mobilization, a number of percutaneous closure devices have been developed. One such device using the nitinol clip was developed by Abbott Vascular Devices and was approved for use on the basis of the results of the Clip Closure In Percutaneous Procedures (CLIP) study. The safety of repuncture through a previously deployed device has not been established in humans. We present the case of a patient who had an arterial line placed for post‐operative monitoring after cardiac surgery at the site of a previous arteriotomy closed with the Starclose device. The catheter traversed through the central portion, tethered to the periphery of the ninitol clip, and required surgery for extraction. © 2009 Wiley‐Liss, Inc.
Automated contrast injectors for angiography: Devices, methodology, and safety
Authors: Kaluski Edo , Moussa Issam D. , Heuser Richard R. , Kern Morton J. , Weisz Giora , Klapholz Marc , Gerula Christine 
Published: February 2009

AbstractAutomated contrast injectors (ACIs) are widely employed in interventional cardiology, radiology and neurology. Information regarding the specifications of advanced ACIs and the appropriate injection settings of these devices is limited in the medical literature. This review describes the specifications of the most widely used ACIs and provides appropriate recommendations for injection settings for the various angiographic studies. These recommendations are based on expert consensus and commercial experience regarding characteristics of devices, catheters and contrast. The suggested settings were not subject to rigorous comparative clinical assessment. This review should increase the familiarity, comfort and appreciation of safety among ACI users. © 2009 Wiley‐Liss, Inc.
Total Synthesis of Rapamycin
Authors: Ley Steven V. , Tackett Miles N. , Maddess Matthew L. , Anderson James C. , Brennan Paul E. , Cappi Michael W. , Heer Jag P. , Helgen Céline , Kori Masakuni , Kouklovsky Cyrille , Marsden Stephen P. , Norman Joanne , Osborn David P. , Palomero María Á. , Pavey John B. J. , Pinel Catherine , Robinson Lesley A. , Schnaubelt Jürgen , Scott James S. , Spilling Christopher D. , Watanabe Hidenori , Wesson Kieron E. , Willis Michael C. 
Published: February 2009

AbstractRapamycin (1) is a macrocyclic natural product, established as a potent immunosuppressant and currently of interest to the scientific community as the framework for a series of novel anticancer drugs. Extensive studies have culminated in a new convergent total synthesis of 1, which features a number of group‐derived methodologies and an unusual catechol‐templating strategy for the construction of the challenging macrocyclic core.magnified imageFor over 30 years, rapamycin has generated a sustained and intense interest from the scientific community as a result of its exceptional pharmacological properties and challenging structural features. In addition to its well known therapeutic value as a potent immunosuppressive agent, rapamycin and its derivatives have recently gained prominence for the treatment of a wide variety of other human malignancies. Herein we disclose full details of our extensive investigation into the synthesis of rapamycin that culminated in a new and convergent preparation featuring a macro‐etherification/catechol‐templating strategy for construction of the macrocyclic core of this natural product.
The Extra‐Framework Sub‐Lattice of the Metal–Organic Framework MIL‐110: A Solid‐State NMR Investigation
Authors: Haouas Mohamed , Volkringer Christophe , Loiseau Thierry , Férey Gérard , Taulelle Francis 
Published: February 2009

AbstractA changeable character: Differences in the dynamics of occluded moieties within the large pores (see graphic) of aluminium 1,3,5‐benzene tricarboxylate framework solid MIL‐110 are a function of the synthesis pH. Host–guest proton‐transfer processes lead to a reversible change in the character of the framework from cationic to neutral, depending on the nature of the extra‐framework moieties.magnified imageThe aluminium 1,3,5‐benzene tricarboxylate framework solid MIL‐110, which crystallises either at pH≈0 or at pH≈4, has been investigated by solid‐state NMR spectroscopy. At pH≈0 the solid (MIL‐110{pH0}) is the unique stable thermodynamic product, whereas at pH≈4 MIL‐110{pH4} is observed as a kinetic product in competition with the MIL‐96 phase. Diffraction studies and 27Al NMR spectroscopy prove that the framework is identical in both cases. The nature and dynamics of occluded moieties within the large pores look quite different for the two compounds. MIL‐110{pH4} and MIL‐110{pH0} both show the presence of occluded 1,3,5‐benzene tricarboxylate (btc), with additional nitrates and water molecules. However, the proportions of btc, nitrates and water are functions of the pH, leading to an identical framework and a quite different extra‐framework. With the extra‐framework moieties, the framework undergoes a proton transfer which is a function of the synthesis pH. Washing the MIL‐110{pH0} phase with water produces a different extra‐framework structure, richer in water and poorer in btc and nitrates. The hydroxyl groups of the inorganic aluminium cluster of the framework are involved in a proton transfer, which leads for all cases to a cationic framework and an anionic extra‐framework. 1H–1H DQ 2D NMR spectra (DQ=double quantum) give evidence for the interaction of extra‐framework btc with the terminal water carried by Al(2,3) and shows their proximity to the closest hydroxyl groups. A structure for the non‐diffracting extra‐framework is proposed as the most plausible topology. It provides an efficient picture for the creation of many substituted MIL‐110 compounds that would have a large number of applications.
ChemInform Abstract: An ab initio Study of Possible Pathways in the Thermal Decomposition of NaAlH4
Authors: Ojwang J. G. O. , van Santen Rutger , Kramer Gert Jan , Ke Xuezhi 
Published: February 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Crystal Chemistry and Thermal Behavior of Anhydrous Phosphates. Part 42. The First Iridiumphosphates.
Authors: Panagiotidis K. , Glaum R. , Hoffbauer W. , Weber J. , Schmedt auf der Guenne J. 
Published: February 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: High‐Pressure Single‐Crystal X‐Ray Diffraction of Tl2SeO4.
Authors: Grzechnik Andrzej , Breczewski Tomasz , Friese Karen 
Published: February 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Crystal Chemistry of Anhydrous Li Uranyl Phosphates and Arsenates. Part 1. Polymorphism and Structure Topology: Synthesis and Crystal Structures of α‐Li[(UO2)(PO4)], α‐Li[(UO2)(AsO4)], β‐Li[(UO2)(AsO4)] and Li2 [(UO2)3(P2O7)2].
Authors: Alekseev Evgeny V. , Krivovichev Sergey V. , Malcherek Thomas , Depmeier Wulf 
Published: February 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: A New Lithium Manganese Phosphate with an Original Tunnel Structure in the A2MP2O7 Family.
Authors: Adam Laure , Guesdon Anne , Raveau Bernard 
Published: February 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.