bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization and thermal degradation of poly(d,l‐lactide‐co‐glycolide) composites with nanofillers
Authors: Palacios Jordana , Albano Carmen , González Gema , Castillo Reina Verónica , Karam Arquímedes , Covis María 
Published: November 2012

AbstractChemical and thermal characterization of poly(d,l‐lactide‐co‐glycolide) (PLGA) composites filled with hydroxyapatite (HA) or carbon nanotubes (CNT) were evaluated by infrared spectroscopy, differential scanning calorimetry, thermogravimetry, and dynamic–mechanical–thermal analysis. The morphology and distribution of the nanoparticles were studied by transmission electron microscopy. The composites were prepared by solvent casting using 30% HA or 1, 3, and 5% of pristine and functionalized CNT as nanoparticles and PLGA 75:25 and PLGA 50:50 as copolymer matrix. The Coats–Redfern and E2 function methodologies were used to calculate the reaction order and the activation energy (Ea) of the thermal degradation process. It was found that the addition of nanoparticles increased the glass transition temperature (Tg) of the composites. Also, higher degradation temperatures and Ea values were obtained for PLGA–HA composites and compared with the neat copolymer, and the opposite behavior was exhibited by PLGA–CNT composites. The thermal and mechanical properties were highly dependent on the morphology and dispersion of the filler. The functionalization process of CNT promoted, to some extent, a better distribution and dispersion of CNT into the matrix, and these composites exhibited a slight enhancement on storage modulus. On the other hand, PLGA–HA composites showed a good dispersion but no improvement on the storage modulus below Tg. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Mechanical properties of high density packed silica/poly(vinyl chloride) composites
Authors: Conradi M. , Zorko M. , Jerman I. , Orel B. , Verpoest I. 
Published: November 2012

AbstractThis article focuses on the preparation and mechanical properties of silica/poly(vinyl chloride) (PVC) composites enriched with 60% mass ratio of 130 nm and 30 nm silica sphere fillers. Silica particles were pre‐treated with silane, IO7 T7(OH)3 (trisilanol isooctyl polyhedral‐oligomeric silsesquioxane) to prevent agglomeration. The dispersion and interfacial compatibility of silica particles in a PVC matrix were investigated by scanning electron microscopy. The composite mechanical properties were characterized by tensile test, revealing improved Young modulus and tensile strength. Compared to pure PVC, the stiffness of 30 nm and 130 nm silica/PVC composites is on average increased by 30–40%, respectively. Similar trend was observed for the composite tensile strength on the change of the silica size. In contrast, elongation at break decreased for both composites compared to pure PVC, for 15% in 30 nm and for 30% in 130 nm silica/PVC composite. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Evaluation of two‐stage process (refining and homogenization) for nanofibrillation of cotton fibers
Authors: Karande V.S. , Mhaske S.T. , Bharimalla A.K. , Hadge G.B. , Vigneshwaran N. 
Published: November 2012

AbstractIn this study, nonspinnable short staple cotton fibers were microfibrillated in disc refiner followed by nanofibrillation in high pressure homogenizer and their properties evaluated. The extent of fibrillation was improved by increased number of repeated passes. Refining as a pretreatment process helps to circumvent the fiber clogging problem in homogenizer nozzle. Microfibrillation by 30 passes in refining produced the fibrils of size 416 ± 177 nm and subsequent nanofibrillation by 15 passes in homogenization resulted in 112 ± 49 nm as revealed by scanning electron microscopy. While refining process does not significantly affect the crystalline index of fibers, homogenization reduced it by 10% due to very high shear and impact forces and hydrodynamic cavitation. The degree of polymerization of cotton fibers was reduced significantly (35.4%) during this two‐stage process. Fourier transform infrared spectroscopy proved that there is no change in the molecular structure of cotton fibrils during this two‐stage fibrillation process. Thus produced nanofibrils having potential application as fillers in composites which can be used for various application food packaging, much films membranes etc. add value to the cotton fibers that are not suitable for spinning in textile industries due to their very short length. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Preparation of long‐chain branching polypropylene and investigation on its foamability
Authors: Zhang Wen , Yang Lili , Chen Peng , Zhang Huaji , Lin Wei , Wang Yuexiang 
Published: November 2012

AbstractIn this work, zinc N,N‐dimethyldithiocarbamate (ZDMC) was used to mediate the melt modification of polypropylene (PP) with 1,6‐hexanediol diacrylate (HDDA) in an internal mixer in the presence of dicumyl peroxide (DCP). Fourier transformed infrared spectroscopy analysis revealed that HDDA was directly grafted onto PP backbone. The dependence of torque on processing time indicated that the presence of ZDMC restrained the degradation of PP, and the end‐torque value increased with the addition of ZDMC. Dynamic rheological measurement indicated that the modified PP possessed higher G′ and lower tan δ at low frequency, displaying an increase in η* and disappearance of Newtonian plateau in η*–ω plot, as well as larger radius of semicircle in Cole–Cole plot. All the rheological characterizations, together with the decreased gel content with the increase of ZDMC, confirmed the formation of long‐chain branching. Subsequently, the foamability of the modified samples was investigated by one‐step compression–molding process. The cellular structure and morphology of the obtained foams were observed by scanning electron microscopy, and the results showed that the addition of ZDMC decreased the cell size, increased the cell density, and brought about well‐defined closed cell structure. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Effect of sintering temperature on internal‐bias field and electric properties of 0.2PZN–0.8PZT ceramics
Authors: Zheng Mupeng , Hou Yudong , Ge Haiyan , Zhu Mankang , Yan Hui 
Published: November 2012

AbstractPiezoelectric ceramics system of Pb((Zn1/3Nb2/3)0.20–(Zr0.50Ti0.50)0.80)O3 (0.2PZN–0.8PZT) was prepared by the conventional oxide mixing method. The dependences of the internal‐bias field and electric properties on the sintering temperature were investigated systematically. The results indicated that the perovskite structure was stable in a wide sintering temperature region. The rise of sintering temperature favored the enlargement of the grain size, while showing a slight effect on tetragonal distortion c/a. The dissymmetrical shape of polarization–electric field hysteresis loops was displayed in all specimens, indicating the existence of internal‐bias field (Ei). With the increase of sintering temperature, Ei sharply decreased to 0.84 kV cm−1 at 1000 °C then increased, while the remnant polarization (Pr) was found to show the inverse trend. The derivative effects of the sintering temperatures, involving the internal‐bias field effect and grain‐size effect, affected the ferroelectric and piezoelectric properties of 0.2PZN–0.8PZT.
Influence of Ga doping on the microstructure of 3C‐SiC layers grown on 4H‐SiC substrates by VLS mechanism
Authors: Marinova Maya , Mantzari Alkyoni , Andreadou Ariadne , Lorenzzi Jean , Ferro Gabriel , Polychroniadis Efstathios K. 
Published: November 2012

AbstractThis work focuses on the Transmission Electron Microscopy investigation of p‐type doped 3C‐SiC layers grown by Vapor‐Liquid‐Solid mechanism using Si‐Ga melts on 4H‐SiC substrates. Ga concentration strongly influences the appearance of defects in the grown layers. Ga inclusions are observed only in the layer grown at the highest temperature and lowest Ga content in the melt. At the highest concentration of Ga in the melt main defects are dislocations forming periodic bands along 〈$ 1\bar10 $〉 and 〈$ \bar211 $〉 directions. The most appropriate conditions (in terms of defect density) for VLS growth using SiGa melts, as defined from the current study, should be growth in Si25Ga75 alloy at T = 1200 ºC. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Privacy protection in human‐centric healthcare home environment
Authors: Seo Deok‐Seok , Kim Soon Seok , Lee Yong Hee , Kim Gwang Hee , Shin Yoon Seok 
Published: November 2012

ABSTRACTThe medical environment has evolved from the one centered on the hospital diagnosis to that centered on the healthcare. The healthcare environment is the technology enabling the remote diagnosis for personal healthcare not only of lonesome old men but also of general households. In relation with it, an international standard technology was published recently that transmits the information from the devices to measure the biometric information of persons to the healthcare center or hospital. But, for its actual application into each household, it is necessary to solve the privacy protection problem. Therefore, this paper proposes a new architecture and system to secure the privacy of person for the newly published international standard technology. The proposed technology is expected to provide a more secure and realistic alternative in the future human‐centric healthcare home environment. Copyright © 2012 John Wiley & Sons, Ltd.
Insulin Inhibits Cardiac Mesoderm, Not Mesendoderm, Formation During Cardiac Differentiation of Human Pluripotent Stem Cells and Modulation of Canonical Wnt Signaling Can Rescue This Inhibition
Authors: Lian Xiaojun , Zhang Jianhua , Zhu Kexian , Kamp Timothy J. , Palecek Sean P. 
Published: November 2012

Abstract
The study of the regulatory signaling hierarchies of human heart development is limited by a lack of model systems that can reproduce the precise developmental events that occur during human embryogenesis. The advent of human pluripotent stem cell (hPSC) technology and robust cardiac differentiation methods affords a unique opportunity to monitor the full course of cardiac induction in vitro. Here, we show that stage-specific activation of insulin signaling strongly inhibited cardiac differentiation during a monolayer-based differentiation protocol that used transforming growth factor β superfamily ligands to generate cardiomyocytes. However, insulin did not repress cardiomyocyte differentiation in a defined protocol that used small molecule regulators of canonical Wnt signaling. By examining the context of insulin inhibition of cardiomyocyte differentiation, we determined that the inhibitory effects by insulin required Wnt/β-catenin signaling and that the cardiomyocyte differentiation defect resulting from insulin exposure was rescued by inhibition of Wnt/β-catenin during the cardiac mesoderm (Nkx2.5+) stage. Thus, insulin and Wnt/β-catenin signaling pathways, as a network, coordinate to influence hPSC differentiation to cardiomyocytes, with the Wnt/β-catenin pathway dominant to the insulin pathway. Our study contributes to the understanding of the regulatory hierarchies of human cardiomyocyte differentiation and has implications for modeling human heart development.
Brief Report: Long-Term Functional Engraftment of Mesenchymal Progenitor Cells in a Mouse Model of Accelerated Aging
Authors: Singh Lakshman , Brennan Tracy A. , Kim Jung-Hoon , Egan Kevin P. , Mcmillan Emily A. , Chen Qijun , Hankenson Kurt D. , Zhang Yi , Emerson Stephen G. , Johnson F. Brad , Pignolo Robert J. 
Published: November 2012

Abstract
Age-related osteoporosis is characterized by a decrease in bone-forming capacity mediated by defects in the number and function of osteoblasts. An important cellular mechanism that may in part explain osteoblast dysfunction that occurs with aging is senescence of mesenchymal progenitor cells (MPCs). In the telomere-based Wrn−/−Terc−/− model of accelerated aging, the osteoporotic phenotype of these mice is also associated with a major decline in MPC differentiation into osteoblasts. To investigate the role of MPC aging as a cell-autonomous mechanism in senile bone loss, transplantation of young wild-type whole bone marrow into Wrn−/−Terc−/− mutants was performed and the ability of engrafted cells to differentiate into cells of the osteoblast lineage was assessed. We found that whole bone marrow transplantation in Wrn−/−Terc−/− mice resulted in functional engraftment of MPCs up to 42 weeks, which was accompanied by a survival advantage as well as delays in microarchitectural features of skeletal aging.
Using SysML modeling to understand and evolve systems of systems
Authors: Lane Jo Ann , Bohn Tim 
Published: November 2012

AbstractThe recent Department of Defense (DoD) guidebook, Systems Engineering Guide for Systems of Systems, describes how traditional systems engineering activities have evolved to support systems engineering at the system of systems (SoS) level. Part of the research for this guidebook probed the application of modeling and simulation to support SoS systems engineering. The findings indicated that limited modeling and simulation are currently used, but that additional support would be useful if models could be quickly generated and used to support needed decision making. This paper presents an approach to using Systems Modeling Language (SysML) models to support these needs. ©2012 Wiley Periodicals, Inc. Syst Eng 16
Evaluation of standard impulse voltage/current measuring systems in Japan
Authors: Wakimoto Takayuki , Ishii Masaru , Miyazaki Satoru 
Published: November 2012

AbstractA national‐standard‐class impulse voltage measuring system in Japan was developed in the consignment research of the Ministry of Economy, Trade and Industry (METI) and New Energy and Industrial Technology Development Organization (NEDO) from 1998 to 2006. The standard measuring system for the impulse voltage measurements is managed by the Japan High Voltage Impulse Testing Laboratories Liaison (JHILL) established under the Japan Electric Machine Industry Association (JEMA). The standard impulse voltage measuring system calibrates other measuring systems and assesses their uncertainties, and, therefore, its uncertainty needs to be evaluated independently. The principal components of the system are a voltage divider, a digital recorder, and a low‐voltage calibrator which generates impulse voltages of known peak voltages and waveforms. Moreover, a reference measuring system for impulse current in Japan was also developed in 2009 supported by JEMA. Its international compatibility was confirmed through an international comparison test. Through domestic comparison tests, traceability among transducers of impulse current in Japan was established. In this paper, the constitution of these measuring systems, their performance, and related latest activities, such as comparison tests, are described. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Generation of three‐dimensional pharmacophore models
Authors: Van Drie John H. 
Published: November 2012

AbstractDifferent approaches to the generation of pharmacophore models—pharmaco‐phore discovery—are compared, and analyzed in detail at the level of their conceptual basis, their theoretical foundations, and the algorithms used to implement them. Strengths and weaknesses of each are discussed, with the aim of pointing toward future developments in this field.This article is categorized under:

Computer and Information Science > Chemoinformatics
Druggability predictions: methods, limitations, and applications
Authors: Barril Xavier 
Published: November 2012

AbstractPharmacological treatment with small organic molecules offers important medical, economic, and practical advantages over other therapeutic approaches. However, such small molecules can only elicit an effect when they bind to a biological component at the appropriate site and with sufficient affinity to modify its behavior. Druggability predictions assess the ability of a given binding site to host drug‐like organic molecules. Combined with information about the involvement of such component in a disease, druggability predictions can be used to prioritize therapeutic targets and are particularly useful when moving beyond the traditional target classes. In the last few years, significant progress has been made to understand the molecular basis of druggability, to compile datasets of targets with various degrees of druggability, and to develop a diverse set of computational prediction methods. These tools offer a better prospect for target‐based drug discovery. © 2012 John Wiley & Sons, Ltd.This article is categorized under:

Computer and Information Science > Chemoinformatics
Technology cooperation for sustainable energy: a review of pathways
Authors: Mallett Alexandra 
Published: November 2012

Policy makers, practitioners and academics agree that addressing climate change requires global efforts and that one pillar of any effective approach must include actions undertaken by developing countries. A key mechanism in which developing countries can be engaged is through collaboration to elicit more use of sustainable energy technologies in a region, organization, or community's energy portfolio. Approaches have tended to emphasize the role of the public and/or private sector. An alternative view has also emerged, termed as community approach, noting the absence of civil society actors in the predominant pathways that often characterize technology cooperation in developing countries. Local engagement is important, as it is often these players [whether local governments, community groups, and/or organizations (e.g. hospitals, schools)] who ultimately reap the benefits and/or bear the costs of these technologies. Recent emphasis centres on an enabling environment, recognizing the importance of creating markets for technology diffusion. Tackling the uptake of sustainable energy in a systematic way, emphasis is placed on policies, actors, and institutions. Building on these foundational frameworks, this paper scrutinizes actors and their relationships with a finer grain to better understand sustainable energy technology uptake. The notion is that sustainable energy technology use will increase with the active engagement of local players (earlier on, in a more meaningful way) in the technology cooperation process.This article is categorized under:

Energy Policy and Planning > Climate and Environment
Energy and Development > Economics and Policy
Catheter Tract Recurrence After Percutaneous Biliary Drainage for Hilar Cholangiocarcinoma
Authors: Kang Mee Joo , Choi Yun‐Suk , Jang Jin‐Young , Han In Woong , Kim Sun‐Whe 
Published: November 2012

AbstractBackgroundDespite its wide use, catheter tract recurrence after percutaneous biliary drainage (PBD) is rarely reported. However, one recent large‐scale study reported a catheter tract recurrence rate as high as 5.2 % in patients with perihilar or distal bile duct cancer. We report on our 20 years of experience with catheter tract seeding after PBD for hilar cholangiocarcinoma.MethodsThe medical records of 441 patients who underwent operation for hilar cholangiocarcinoma between 1991 and 2011 were retrospectively analyzed.ResultsOf the 441 patients with hilar cholangiocarcinoma, PBD was performed in 315 patients, and 232 others underwent resection of hilar cholangiocarcinoma with PBD. Catheter tract recurrence developed in 6 patients (2.6 %). The median drainage duration was 30 days, and 1 patient had multiple PBDs. The median time to catheter recurrence after surgery was 10.9 months. Three patients underwent curative resection of the abdominal wall followed by chemotherapy, 1 patient underwent chemotherapy only, and 2 patients received conservative treatment. Five patients in whom the catheter tract recurrence was their first recurrence died of systemic recurrence at median 3.9 months after detection of catheter tract seeding. T1 or 2 disease (66.7 vs. 31.3 %; p = 0.086) tended to have catheter tract seeding with marginal significance. The overall survival rate was lower in patients with catheter tract seeding than in those without (median 17.5 vs. 23.0 months; p = 0.089).ConclusionsThe PBD catheter tract recurrence rate for hilar cholangiocarcinoma was 2.6 %. However, patients with catheter tract recurrence had a poor prognosis despite complete surgical metastasectomy.
Continuous Noninvasive Hemoglobin Monitor from Pulse Ox: Ready for Prime Time?
Authors: Joseph Bellal , Hadjizacharia Pantelis , Aziz Hassan , Snyder Kara , Wynne Julie , Kulvatunyou Narong , Tang Andrew , O’Keeffe Terence , Latifi Rifat , Friese Randall , Rhee Peter 
Published: November 2012

AbstractBackgroundAdvances in technology have allowed for continuous noninvasive hemoglobin monitoring (SpHb), which may enable earlier detection of hemorrhage and more efficient surgical and/or blood transfusion management. The use of SpHb has not been described in the trauma population. The purpose of the present study was to evaluate the accuracy of a SpHb measurement device in severely injured trauma patients.MethodsWe performed a prospective cohort analysis of severely injured trauma patients admitted to the intensive care unit (ICU) at our level I trauma center over a 6 month period. Serial IHb (invasive hemoglobin) levels and SpHb for the first 72 h were measured. Each SpHb measurement was matched with a corresponding IHb measurement. We defined normal Hgb as >8 mg/dL and low Hgb as <8 mg/dL. Data were then grouped based on Hgb level. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and Spearman correlation coefficient plot were calculated.ResultsA total of 23 trauma patients with 89 data pairs were reviewed. Eighty‐six percent of the patients were male with a mean age of 32 years and a mean injury severity score (ISS) of 21.1 ± 14. Invasive hemoglobin had a range of 7.2–16.9 and SpHb had a range of 3.3–15.2. The average mean and difference between IHb and SpHb were 10.7 and 1, respectively. Continuous noninvasive hemoglobin measurement did not record data points 13.5 % of the time. The Spearman correlation plot revealed a correlation of R = 0.670 (p < 0.001). After dichotomization with Hgb > 8, SpHb was found to have a sensitivity of 91 %, PPV 96 %, specificity 40 %, NPV 20 %, and an accuracy of 88 %.ConclusionsThe continuous noninvasive hemoglobin monitor does not appear to represent serum hemoglobin levels accurately in severely injured trauma patients. However, we were able to identify utility for this noninvasive tool when Hgb was dichotomized into normal or low levels.
Immobilization of Trametes versicolor cultures for improving laccase production in bubble column reactor intensified by sonication
Authors: Wang Feng , Guo Chen , Liu Chun-Zhao 
Published: November 2012

Abstract
The mycelia of Trametes versicolor immobilized in alginate beads provided higher laccase production than that in pelleted form. An efficient ultrasonic treatment enhanced laccase production from the immobilized T. versicolor cultures. The optimized treatment process consisted of exposing 36-h-old bead cultures to 7-min ultrasonic treatments twice with a 12-h interval using a fixed ultrasonic power and frequency (120 W, 40 kHz). Using the intensification strategy with sonication, laccase production increased by more than 2.1-fold greater than the untreated control in both flasks and bubble column reactors. The enhancement of laccase production by ultrasonic treatment is related to the improved mass transfer of nutrients and product between the liquid medium and the gel matrix. These results provide a basis for the large-scale and highly-efficient production of laccase using sonobioreactors.