bluuebunny/crossref_metadata_2025 huggingface dataset:
Production of Nanofibrillated Cellulose by Mechanical Dissociation
Authors: Köster Alexander , Förter‐Barth Ulrich , Herrmann Michael , Schweppe Rainer , Teipel Ulrich
Published: February 2014

Mithilfe eines zweistufigen Verfahrens, bestehend aus der Dispergierung in Natronlauge und dem anschließenden mechanischen Aufschluss in einer Rührwerkskugelmühle, konnte ein Cellulosevlies in nanoskalige Fibrillen mit Durchmessern im Bereich von einigen nm bis etwa 30 nm aufgeschlossen werden. Dies zeigen auch die Kristallstrukturanalysen, die mit einer tendenziell verfeinerten Kritallitgröße im Bereich der Fibrillendurchmesser auf den Aufschluss der Cellulose in Nanofibrillen hindeuten. Die Faserlänge konnte dabei weitestgehend erhalten bleiben.
Estimation of molecular and thermodiffusion coefficients for non‐ideal molten metal alloys and its implication in solidification process
Authors: Jafar‐Salehi Elham , Eslamian Morteza , Saghir M. Ziad
Published: February 2014

In this paper an expression is proposed for the estimation of thermodiffusion factor in liquid metal alloys. The expression can be readily used given that it requires properties that could be easily obtained from the physical properties of the mixture constituents, such as viscosity and molar volume. The predictive power of the proposed expression, as well as other pertinent models is examined against the experimental data. The estimated thermodiffusion factor is then used to study thermo‐solutal convection in an enclosure filled with molten Sn–Bi alloy by solving the transport equations numerically. Two simulations were carried out in a vertical rectangular cell encapsulated by a quartz container: top heating and bottom heating. The sidewalls in both cases were exposed to the external natural convection and surface radiation to the ambient. Numerical results show that in the top heating case, the distribution of temperature and concentration are linear, but species segregation occurs due to the thermodiffusion effect. In the bottom heating case, boundary‐driven convective flow develops with a large Rayleigh number (Ra) where an increase in the Ra number negates the thermodiffusion effect due to the development of strong mixing.
Bootstrap methods for imputed data from regression, ratio and hot‐deck imputation
Authors: Mashreghi Zeinab , Léger Christian , Haziza David
Published: February 2014

Item non‐response in sample surveys is usually addressed by imputation. A bootstrap method that treats the imputed values as if they were observed generally leads to variance estimates that are too small. Shao & Sitter (1996) introduced a bootstrap method in this context, which leads to consistent variance estimators when the sampling fraction is small. In the context of stratified simple random sampling, we introduce the independent bootstrap, which is valid even when the sampling fraction is large. It consists of modifying a bootstrap method for sample surveys, of independently generating the response status of each unit, and of imputing the non‐respondents in the bootstrap sample. We pay special attention to the bootstrap survey weights approach of Rao, Wu, & Yue (1992). The Canadian Journal of Statistics 42: 142–167; 2014 © 2014 Statistical Society of Canada
Modeling and analyzing the energy consumption of fork‐join‐based task parallel programs
Authors: Rauber Thomas , Rünger Gudula
Published: February 2014

Because of environmental and monetary concerns, it is increasingly important to reduce the energy consumption in all areas, including parallel and high performance computing. In this article, we propose an approach to reduce the energy consumption needed for the execution of a set of tasks computed in parallel in a fork‐join fashion. The approach consists of an analytical model for the energy consumption of a parallel computation in fork‐join form on dynamic voltage frequency scaling processors, a theoretical specification of an energy‐optimal frequency‐scaled state, and the energy minimization by computing optimal scaling factors. For larger numbers of tasks, the approach is extended by scheduling algorithms, which exploit the analytical result and aim at a reduction of the energy. Energy measurements of a complex numerical method and the SPEC CPU2006 benchmarks as well as simulations for a large number of randomly generated tasks illustrate and validate the energy modeling, the minimization, and the scheduling results. Copyright © 2014 John Wiley & Sons, Ltd.
Multi‐topology routing based egress selection approach to achieve hybrid intra‐AS and inter‐AS traffic engineering
Authors: Li Ke , Wang Sheng , Xu Shizhong , Wang Xiong , Ren Jin , Huang Haojun , Zhai Bo
Published: February 2014

Hot‐potato routing is a border gateway protocol policy that selects the ‘closest’ egress router in terms of interior gateway protocol cost. This policy imposes inherent interactions between intra‐AS (Autonomous System) and inter‐AS traffic engineering. In light of this observation, we present a hybrid intra‐AS and inter‐AS traffic engineering scheme named egress selection based upon hot potato routing. This scheme involves link weight optimization, which can not only minimize the time that IP (Internet Protocol) packets travel across the network by assigning specified egress router but also balance the load among the internal links of the transit network. Egress selection based upon hot potato routing also incorporates multi‐topology routing technique to address the problem that one set of link weights might not guarantee specified egress routers. Accordingly, we formulate the link weights optimization problem using multi‐topology routing as a mixed integer linear programming model. And we present a new heuristic algorithm to make the problem tractable. Numerical results show that only a few topologies are needed to guarantee specified egress router, and maximum link utilization is also reduced. Copyright © 2014 John Wiley & Sons, Ltd.
Neural Transplantation Model Using Integration Co‐Culture Chamber
Authors: Shimba Kenta , Saito Atsushi , Takeuchi Akimasa , Takayama Yuzo , Kotani Kiyoshi , Jimbo Yasuhiko
Published: February 2014

Regenerative medicine is a promising therapy for injuries and diseases of the central nervous system (CNS). Implantation of stem cell‐derived neurons into the recipient tissue is one of the key processes of the therapy. How the implanted cells establish functional connections with the intact neurons, and whether the established connections are maintained stably for a long time, remain unknown. Here, we report a novel co‐culture device for visualizing interconnections between primary and differentiated neuronal cultures, and long‐term monitoring of neuronal activity. A circular microchamber surrounded by another chamber is aligned on a microelectrode array (MEA). These chambers are interconnected through 36 microtunnels. Stem cell‐derived neurons were cultured in the inner circular chamber, and primary neurons taken from mouse cortices were cultured in the surrounding chamber. Neurites outgrew into the microtunnels from both primary and differentiated neurons. Immunofluorescence images indicated that synaptic connections were formed between them. Propagation of electrical activity was observed 6 days after starting co‐culture. More than half of the spontaneous activity was initiated from primary neurons, and the probability of activity propagation to the stem cell‐derived neurons gradually increased with culture days. These results suggest that our device is feasible for long‐term monitoring of the interaction between stem cell‐derived cells and the recipient tissue.
Decoding of Auditory Information from Steady‐State Neural Activity in Rat Auditory Cortex
Authors: Shiramatsu Tomoyo Isoguchi , Akutsu Kan , Znoda Takahiro , Kanzaki Ryohei , Takahashi Hirokazu
Published: February 2014

In the auditory cortex, auditory‐evoked onset activities have been extensively investigated as a cortical representation of sound information and the emotional information that is associated with sound. However, less attention has been paid to date to steady‐state activities following onset activities. In this study, we used machine learning to investigate whether steady‐state neural activities in the presence of continuous sound represented the sound frequency and the emotion that was associated with the sound. A microelectrode array with a grid of 96 sites recorded local field potentials (LFPs) in the fourth layer of the auditory cortex of anesthetized rats, and sparse logistic regression (SLR) decoded the sound frequency from the steady‐state neural activities of the LFPs. The band‐specific power at every recording site and the phase locking values between every pair of recording sites served as the input vectors for SLR. In addition, we investigated how these decoding accuracies depended on either aversive or appetitive auditory classical conditioning. We found that the SLR was able to decode the sound frequency from the steady‐state neural activities as well as the onset activities and that the decoding accuracy in particular bands either significantly improved or worsened in a conditioning‐dependent manner. These results demonstrated that the steady‐state neural activities contained rich information about not only test sounds but also the emotions that were associated with the sounds.
A Circuit Design Method for Dynamic Reconfigurable Circuits
Authors: Sawano Hajime , Kambe Takashi
Published: February 2014

Reconfigurable computing (RC) is a new paradigm that addresses the conflicting design requirements of high performance and high area density. Coarse‐grained architecture RC (CGA‐RC) operates at the word level of granularity and exhibits better power and performance features than fine‐grained architectures. However, in a CGA‐RC system, the processing elements (PE) implement several types of arithmetic operations and the routing between them has a fixed architecture. To achieve both good performance and high PE utilization for all applications, this paper proposes an interactive circuit design methodology for dynamically reconfigurable processors to accelerate their performance and achieve compact circuits. The method is applied to a JPEG encoder design and its performance evaluated.
An Anomaly Detection Method for Individual Services on a Web‐Based System by Selection of Dummy Variables in Multiple Regression
Authors: Tsuda Yuki , Samejima Masaki , Akiyoshi Masanori , Komoda Norihisa , Yoshino Matsuki
Published: February 2014

This paper addresses the detection of anomalies of individual service from their total resource usage on a web‐based system. Because the total resource usage is a linear combination of the number of accesses to each service, multiple regression analysis can be used to estimate the resource usage per access to each service in the form of regression coefficients. However, the regression coefficients differ from the resource usage per access of the services, due to unstable resource usage per access. We propose a method based on the multiple correlation coefficient R to identify anomaly times and anomaly services. The proposed method identifies an anomaly time when the R value is decreased; it identifies an anomaly service by judging whether R value has increased after the selection of the dummy variable. Experimental results show that the proposed method can identify all anomaly times, and that it improves the precision rate and recall rate of anomaly service detection by at least 20%.
Toward product control in ring‐opening oligomerization of 9H‐9‐borafluorenes
Authors: Zhu Hui , Qu Zheng‐Wang
Published: February 2014

To get deep insights into the structure–reactivity relationship for ring‐opening oligomerization reactions toward targeted design of novel main‐chain boron‐containing materials, detailed DFT B97D/TZVP calculations are carried out to compare the ring‐opening oligomerization of both unsubstituted and tert‐butyl (tBu)‐substituted 9H−9‐borafluorenes. In contrast to substituent exchange between normal boranes, such reactions are initiated by substituent exchanges involving double BCB bridged intermediates. On tBu‐substitution, the BCB, and BHB bridged dimer intermediate is stabilized mainly due to enhanced barrier of 18.1 kcal/mol toward further trimerization channel and higher isomerization barrier of 22.5 kcal/mol toward the double BHB bridged dimer. In good agreement with available experiments, it is clearly shown that various product channels can be efficiently controlled by bulky substitution and by reaction temperatures, pointing out the way toward desired higher oligomers with improved thermal stability. © 2014 Wiley Periodicals, Inc.
Quantum‐chemical analyses of aromaticity, UV spectra, and NMR chemical shifts in plumbacyclopentadienylidenes stabilized by Lewis bases
Authors: Kawamura Toshiaki , Abe Minori , Saito Masaichi , Hada Masahiko
Published: February 2014

We carried out a series of zeroth‐order regular approximation (ZORA)‐density functional theory (DFT) and ZORA‐time‐dependent (TD)‐DFT calculations for molecular geometries, NMR chemical shifts, nucleus‐independent chemical shifts (NICS), and electronic transition energies of plumbacyclopentadienylidenes stabilized by several Lewis bases, (Ph)2(tBuMe2Si)2C4PbL1L2 (L1, L2 = tetrahydrofuran, Pyridine, N‐heterocyclic carbene), and their model molecules. We mainly discussed the Lewis‐base effect on the aromaticity of these complexes. The NICS was used to examine the aromaticity. The NICS values showed that the aromaticity of these complexes increases when the donation from the Lewis bases to Pb becomes large. This trend seems to be reasonable when the 4n‐Huckel rule is applied to the fractional π‐electron number. The calculated 13C‐ and 207Pb‐NMR chemical shifts and the calculated UV transition energies reasonably reproduced the experimental trends. We found a specific relationship between the 13C‐NMR chemical shifts and the transition energies. As we expected, the relativistic effect was essential to reproduce a trend not only in the 207Pb‐NMR chemical shifts and J[Pb‐C] but also in the 13C‐NMR chemical shifts of carbons adjacent to the lead atom. © 2014 Wiley Periodicals, Inc.
3,4‐Ethylenedioxythiophene Functionalizationed with Tetrathiafulvalene: Synthesis and Selective Esterification
Authors: Zhang Lei , Wu Changzhi , Wang Chengyun , Zuo Hujin , Shen Yongjia
Published: February 2014

3,4‐(Hydroxymethyl‐ethylenedioxy)thiophene (4) and 3,4‐(2′‐hydroxypropylenedioxy)thiophene (4'′) were synthesized from dimethyl 3,4‐dihydroxythiophene‐2,5‐dicarboxylate (1), which were isomers and difficult to separate. When they were esterified with tetrathiafulvalene carried carboxylic acid group, only 3,4‐(hydroxymethyl‐ethylenedioxy)thiophene (4) could be esterified. No such selectivity was observed when the isomers were esterified by lauric acid and benzoic acid, respectively.
Three‐dimensional regional strain computation method with displacement encoding with stimulated echoes (DENSE) in non‐ischemic, non‐valvular dilated cardiomyopathy patients and healthy subjects validated by tagged MRI
Authors: Kar Julia , Knutsen Andrew K. , Cupps Brian P. , Zhong Xiaodong , Pasque Michael K.
Published: February 2014

Purpose

Fast cine displacement encoding with stimulated echoes (DENSE) MR has higher spatial resolution and enables rapid postprocessing. Thus we compared the accuracy of regional strains computation by DENSE with tagged MR in healthy and non‐ischemic, non‐valvular dilated cardiomyopathy (DCM) subjects.

Materials and Methods

Validation of three‐dimensional regional strains computed with DENSE was conducted in reference to standard tagged MRI (TMRI) in healthy subjects and patients with DCM. Additional repeatability studies in healthy subjects were conducted to increase confidence in DENSE. A meshfree multiquadrics radial point interpolation method (RPIM) was used for computing Lagrange strains in sixteen left ventricular segments. Bland‐Altman analysis and Student's t‐tests were conducted to observe similarities in regional strains between sequences and in DENSE repeatability studies.

Results

Regional circumferential strains ranged from −0.21 ± 0.07 (Lateral–Apex) to −0.11 ± 0.05 (Posterorseptal–Base) in healthy subjects and −0.15 ± 0.04 (Anterior–Apex) to −0.02 ± 0.08 (Posterorseptal–Base) in DCM patients. Computed mean differences in regional circumferential strain from the DENSE‐TMRI comparison study was 0.01 ± 0.03 (95% limits of agreement) in normal subjects, −0.01 ± 0.06 in DCM patients and 0.0 ± 0.02 in repeatability studies, with similar agreements in longitudinal and radial strains.

Conclusion

We found agreement between DENSE and tagged MR in patients and volunteers in terms of evaluation of regional strains. J. Magn. Reson. Imaging 2015;41:386–396.© 2013 Wiley Periodicals, Inc.
Chronic exposure to ethanol of male mice before mating produces attention deficit hyperactivity disorder‐like phenotype along with epigenetic dysregulation of dopamine transporter expression in mouse offspring
Authors: Kim Pitna , Choi Chang Soon , Park Jin Hee , Joo So Hyun , Kim Soo Young , Ko Hyun Myung , Kim Ki Chan , Jeon Se Jin , Park Seung Hwa , Han Seol‐Heui , Ryu Jong Hoon , Cheong Jae Hoon , Han Jung Yeol , Ko Ki Narm , Shin Chan Young
Published: February 2014

Preconception exposure to EtOH through the paternal route may affect neurobehavioral and developmental features of offspring. This study investigates the effects of paternal exposure to EtOH before conception on the hyperactivity, inattention, and impulsivity behavior of male offspring in mice. Sire mice were treated with EtOH in a concentration range approximating human binge drinking (0–4 g/kg/day EtOH) for 7 weeks and mated with untreated females mice to produce offspring. EtOH exposure to sire mice induced attention deficit hyperactivity disorder (ADHD)‐like hyperactive, inattentive, and impulsive behaviors in offspring. As a mechanistic link, both protein and mRNA expression of dopamine transporter (DAT), a key determinant of ADHD‐like phenotypes in experimental animals and humans, were significantly decreased by paternal EtOH exposure in cerebral cortex and striatum of offspring mice along with increased methylation of a CpG region of the DAT gene promoter. The increase in methylation of DAT gene promoter was also observed in the sperm of sire mice, suggesting germline changes in the epigenetic methylation signature of DAT gene by EtOH exposure. In addition, the expression of two key regulators of methylation‐dependent epigenetic regulation of functional gene expression, namely, MeCP2 and DNMT1, was markedly decreased in offspring cortex and striatum sired by EtOH‐exposed mice. These results suggest that preconceptional exposure to EtOH through the paternal route induces behavioral changes in offspring, possibly via epigenetic changes in gene expression, which is essential for the regulation of ADHD‐like behaviors. © 2014 Wiley Periodicals, Inc.
Global stability of a virus dynamics model with intracellular delay and CTL immune response
Authors: Li Xiaojuan , Fu Shengmao
Published: February 2014

In this paper, the global stability of a virus dynamics model with intracellular delay, Crowley–Martin functional response of the infection rate, and CTL immune response is studied. By constructing suitable Lyapunov functions and using LaSalles invariance principle, the global dynamics is established; it is proved that if the basic reproductive number, R0, is less than or equal to one, the infection‐free equilibrium is globally asymptotically stable; if R0 is more than one, and if immune response reproductive number, R0, is less than one, the immune‐free equilibrium is globally asymptotically stable, and if R0 is more than one, the endemic equilibrium is globally asymptotically stable. Copyright © 2014 John Wiley & Sons, Ltd.
Explicit free‐floating beam element
Authors: Nielsen Martin B. , Krenk Steen
Published: February 2014

A two‐node free‐floating beam element capable of undergoing arbitrary large displacements and finite rotations is presented in explicit form. The configuration of the beam in three‐dimensional space is represented by the global components of the position of the beam nodes and an associated set of convected base vectors (directors). The local constitutive stiffness is derived from the complementary energy of a set of six independent deformation modes, each corresponding to an equilibrium state of constant internal force or moment. The deformation modes are characterized by generalized strains, formed via scalar products of the element related vectors. This leads to a homogeneous quadratic strain definition in terms of the generalized displacements, whereby the elastic energy becomes at most bi‐quadratic. Additionally, the use of independent equilibrium modes to set up the element stiffness avoids interpolation of kinematic variables, resulting in a locking‐free formulation in terms of three explicit matrices. A set of classic benchmark examples illustrates excellent performance of the explicit beam element. Copyright © 2014 John Wiley & Sons, Ltd.
Antimicrobial silica particles loaded with quaternary ammonium polyethyleneimine network
Authors: Farah Shady , Aviv Oren , Laout Natalia , Ratner Stanislav , Beyth Nurit , Domb Abraham J.
Published: February 2014

Silica particles functionalized with quaternary ammonium groups were prepared by interpenetrating polyethylenimine (PEI) into silica particles and crosslinking with diiodopentane, followed by octyliodide alkylation and methyliodide quaternarization (S‐QA‐PEI). The synthesized S‐QA‐PEI particles were identified with a slight particle size increase of 2–3 µm. Different ratios of PEI:silica particles were prepared and analyzed. While silica particles are negatively charged, −16.7 ± 5.11 mV, the prepared S‐QA‐PEI particles are positively charged, +50–60 mV. These particles were embedded in poly(ethylene vinyl acetate) and poly(ethylene methacrylic acid) coatings which exhibited strong antibacterial activity. Copyright © 2014 John Wiley & Sons, Ltd.
Characterization of InGaAsN solar‐cell structures on Ge substrates
Authors: Uesugi K. , Kuboya S. , Sanorpim S. , Onabe K.
Published: February 2014

A GaAs/InGaAsN p‐i‐n solar‐cell structure on a Ge substrate has been fabricated intending incorporation in high‐efficiency InGaP/InGaAs/InGaAsN/Ge four‐junction‐structure solar cells. An improved InGaAsN MOVPE growth process is adopted in which the Ge(001) vicinal substrates and a two‐step‐growth GaAs buffer layer combined with post‐growth rapid thermal annealing (RTA) are the keys. With a prototype p‐i‐n photo‐cell, the photovoltaic effect and a photo‐current edge shift to the longer wavelength of InGaAsN with 1 eV bandgap are demonstrated. After RTA, however, the I‐V characteristics are degraded with a significant reverse‐bias current leakage. Electrical measurements showed a conduction‐type conversion from n‐type to p‐type and significant increase of the hole concentration. The N‐H‐VGa complexes acting as shallow acceptors formed through RTA may be the most feasible cause of the drastic change of the electrical property of the InGaAsN film after RTA. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Wafer‐scale GaN HEMT performance enhancement by diamond substrate integration
Authors: Via G. D. , Felbinger J. G. , Blevins J. , Chabak K. , Jessen G. , Gillespie J. , Fitch R. , Crespo A. , Sutherlin K. , Poling B. , Tetlak S. , Gilbert R. , Cooper T. , Baranyai R. , Pomeroy J. W. , Kuball M. , Maurer J. J. , Bar‐Cohen A.
Published: February 2014

A wafer‐scale comparison of HEMTs fabricated on as‐grown GaN/Si and HEMTs fabricated in parallel on epitaxial layers from the GaN/Si growth integrated with a diamond substrate are presented. Diamond, which offers the highest room‐temperature thermal conductivity of any bulk material, is being evaluated as a solution for thermal limitations observed in GaN‐based devices. This paper will present electrical and thermal data collected at the wafer scale demonstrating the improvement realized by integration of a high‐thermal‐conductivity substrate. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling Gas Transmission in Cylindrical Dynamic Accumulation Oxygen Transmission Rate Chambers to Explore Implications of Oxygen Sensor Location Relative to Samples
Authors: Abdellatief Ayman , Welt Bruce A. , Butler Jason , McLamore Eric , Teixeira Arthur A. , Shukla Sanjay
Published: February 2014

A model was developed to simulate oxygen accumulation in space and time within cylindrical dynamic accumulation chambers that are used to measure oxygen transmission rate (OTR) of materials. The model is based on Fick's law of diffusion and was validated against actual OTR measurements of polymer film samples. Measured OTR values and thicknesses were inputted into the model and oxygen concentrations outputted by the model. OTRs determined from the output of the model was in close agreement to within 0.3–3% of the measured OTR. Oxygen concentration versus time curves generated from model output oxygen concentrations and experimentally measured oxygen concentrations for three actual films were also in agreement. The model was then used to simulate results from three hypothetical test films at varying chamber lengths in order to evaluate effects of accumulation chamber dimensions relative to films on resulting OTR measurements. A typical design scenario was used, where the oxygen sensor is mounted on the chamber wall opposite the sample film. Results demonstrate that dynamic accumulation OTR instrument designers have considerable flexibility in choosing accumulation chamber dimensions because deviations in OTR are only expected to occur at impractically extreme chamber lengths (>10 m) for the entire envelope of OTRs expected for typical packaging films. Copyright © 2014 John Wiley & Sons, Ltd.
(Corn Starch and Montmorillonite Nanocomposite)‐Reinforced Polypropylene: Preparation, Properties, and Biodegradability
Authors: Hanifi Saeed , Oromiehie Abdulrasoul , Ahmadi Shervin , Farhadnejad Hassan
Published: February 2014

Blends of polypropylene and thermoplastic starch (TPS) containing different amounts of TPS were prepared with and without modified montmorillonite (C30B) in the presence of ethylene‐(vinyl acetate) copolymer. Mechanical properties, thermal stability, morphology, and biodegradation were investigated. The results of tensile tests showed that the tensile strength and Young's modulus increased but that elongation at break decreased in the presence of C30B. Small‐angle X‐ray scattering patterns and transmission electron microscopy confirmed that the prepared nanocomposites were exfoliated. Scanning electron microscopy (SEM) was used for the investigation of the phase morphology and particle distribution. Thermal gravimetric analysis indicated that the C30B caused an increase in thermal degradation temperature. Biodegradability tests of the specimens were conducted in a fungal culture medium. Biodegradation was assessed by SEM images, monitoring the changes in the FTIR spectra, and the weight loss of specimens after culturing. J. VINYL ADDIT. TECHNOL., 20:16–23, 2014. © 2014 Society of Plastics Engineers
Zinc maleate and calcium stearate as a complex thermal stabilizer for poly(vinyl chloride)
Authors: Wang Ming , Li Haixia , Huang Xingliang , Yi Li
Published: February 2014

Zinc maleate (ZnMA) and calcium maleate (CaMA) were synthesized by reaction of maleic acid with the corresponding metal oxides and were characterized by X‐ray diffraction, thermal analysis, and Fourier‐transform infrared (FTIR) spectroscopy. The thermal stabilizing effects of ZnMA and CaMA on poly(vinyl chloride) (PVC) were investigated at 180°C in air by a static stability test. The stabilization mechanism of ZnMA and the synergism of ZnMA/CaSt2 (St = stearate) were also studied by UV‐visible and FTIR spectroscopies, as well as a thermal stability test. The PVC with the ZnMA stabilizer exhibited good thermal and color stability caused by the ability of ZnMA to replace the labile chlorine atoms in PVC chains, absorb hydrogen chloride, and react with the polyene intermediates via a Diels–Alder mechanism. The gel content of the PVC/ZnMA samples reached 31% after 2 min of heating and 44% after 10 min, thereby indicating that crosslinking could easily occur with ZnMA, probably owing to catalysis by Zn species. The static and dynamic stability results showed that the synergistic effect of the ZnMA/CaSt2 stabilizer was greater than that of ZnSt2/CaSt2. J. VINYL ADDIT. TECHNOL., 20:1–9, 2014. © 2014 Society of Plastics Engineers
Spectral tensor parameters for wind turbine load modeling from forested and agricultural landscapes
Authors: Chougule A. , Mann J. , Segalini A. , Dellwik E.
Published: February 2014

A velocity spectral tensor model was evaluated from the single‐point measurements of wind speed. The model contains three parameters representing the dissipation rate of specific turbulent kinetic energy, a turbulence length scale and the turbulence anisotropy. Sonic anemometer measurements taken over a forested and an agricultural landscape were used to calculate the model parameters for neutral, slightly stable and slightly unstable atmospheric conditions for a selected wind speed interval. The dissipation rate above the forest was nine times that at the agricultural site. No significant differences were observed in the turbulence length scales between the forested and agricultural areas. Only a small difference was observed in the turbulence anisotropy at the two sites, except near the surface, where the forest turbulence was more isotropic. The turbulence anisotropy remained more or less constant with height at the forest site, whereas the turbulence became more isotropic with height for the agricultural site. Using the three parameters as inputs, we quantified the performance of the model in coherence predictions for vertical separations. The model coherence of all the three velocity components was overestimated for the analyzed stability classes at both sites. As expected from the model approximations, the model performed better at both sites for neutral stability than slightly stable and unstable conditions. The model prediction of coherence of the along‐wind and vertical components was better than that of the cross‐wind component. No significant difference was found between the performance of the model at the forested and the agricultural areas. © 2014 The Authors. Wind Energy published by John Wiley & Sons, Ltd.
Hydrogen generation from biomass materials: challenges and opportunities
Authors: Mohanty Pravakar , Pant Kamal K. , Mittal Ritesh
Published: February 2014

In this review, various processes for conversion of ligno(hemi)cellulosic biomass into hydrogen gas are comprehensively reviewed in terms of two main groups, namely (1) thermochemical processes [pyrolysis, catalytic pyrolysis, different gasification, co‐gasification, supercritical water gasification (SCWG)] and (2) biochemical‐cum‐biological conversions, along with electrolytic and photolytic processes. This review depicts much about the thermochemical processes for hydrogen production and its utilization via pyrolysis of biomass, gasification, gasification combined with pyrolysis, supercritical water (fluid‐gas) extraction, steam reforming (SR), auto thermal reforming (ATR), dry reforming (DR), liquid phase reforming (LPR), aqueous‐phase reforming (APR), and partial oxidation (POX) of renewable carboxylates such as bioethanol, acetic acid, phenol, glycerol, carbohydrates, different water‐soluble sugars, and bio‐oil, which are some of the areas to be explored for widespread awareness of hydrogen usage. Biomass‐based hydrogen production systems are emphasized and discussed in terms of their energetic and exergetic aspects with the help of reaction mechanisms. Different oxygenate compounds as derived from biomass with their potential catalyst tested by several literature studies and potential methods are then summarized. WIREs Energy Environ 2015, 4:139–155. doi: 10.1002/wene.111

This article is categorized under:

Bioenergy > Science and Materials

Fuel Cells and Hydrogen > Science and Materials

Fuel Cells and Hydrogen > Systems and Infrastructure

Energy and Development > Science and Materials
The Small Abnormal Parathyroid Gland is Increasingly Common and Heralds Operative Complexity
Authors: McCoy Kelly L. , Chen Naomi H. , Armstrong Michaele J. , Howell Gina M. , Stang Michael T. , Yip Linwah , Carty Sally E.
Published: February 2014

Background

Over decades, improvements in presymptomatic screening and awareness of surgical benefits have changed the presentation and management of primary hyperparathyroidism (PHPT). Unrecognized multiglandular disease (MGD) remains a major cause of operative failure. We hypothesized that during parathyroid surgery the initial finding of a mildly enlarged gland is now frequent and predicts both MGD and failure.

Methods

A prospective database was queried to examine the outcomes of initial exploration for sporadic PHPT using intraoperative PTH monitoring (IOPTH) over 15 years. All patients had follow‐up ≥6 months (mean = 1.8 years). Cure was defined by normocalcemia at 6 months and microadenoma by resected weight of <200 mg.

Results

Of the 1,150 patients, 98.9 % were cured and 15 % had MGD. The highest preoperative calcium level decreased over time (p < 0.001) and varied directly with adenoma weight (p < 0.001). Over time, single adenoma weight dropped by half (p = 0.002) and microadenoma was increasingly common (p < 0.01). MGD risk varied inversely with weight of first resected abnormal gland. Microadenoma required bilateral exploration more often than macroadenoma (48 vs. 18 %, p < 0.01). When at exploration the first resected gland was <200 mg, the rates of MGD (40 vs. 11 %, p = 0.001), inadequate initial IOPTH drop (67 vs. 79 %, p = 0.002), operative failure (6.6 vs. 0.7 %, p < 0.001), and long‐term recurrence (1.6 vs. 0.3 %, p = 0.007) were higher.

Conclusions

Single parathyroid adenomas are smaller than in the past and require more complex pre‐ and intraoperative management. During exploration for sporadic PHPT, a first abnormal gland <200 mg should heighten suspicion of MGD and presages a tenfold higher failure rate.
The potential of exosomes in diagnosis and treatment of inborn errors of metabolism
Authors: van Balkom Bas W. M. , van Doorn Jaap , Verhoeven‐Duif Nanda M. , Verhaar Marianne C.
Published: February 2014

Extracellular vesicles, in particular exosomes, have gained much attention as potent mediators of intercellular signaling. Exosomes are 50–130 nm intraluminal vesicles of multivesicular bodies (MVB) that are secreted into the extracellular environment upon fusion of MVB with the plasma membrane. Current research on exosomes focuses on their biogenesis, including specific sorting mechanisms, their potential to transfer proteins and RNA from their cells of origin to target cells, specific methods of vesicle isolation, and their possible application as diagnostic and therapeutic devices. Exosomes are vesicles of endocytic origin that contain a portion of the cytoplasm. Their molecular components represent the composition and thereby the physiological state of the cells from which they originate. In this review, we recapitulate the discovery of exosomes and the subsequent expansion of exosome research into a variety of different areas of interest, with a specific focus on how exosomes could prove to be invaluable for both diagnostic and therapeutic applications within the research field of inborn errors of metabolism.
Measuring help‐seeking behaviors: Factor structure, reliability, and validity among youth with disabilities
Authors: Pham Yen K. , McWhirter Ellen Hawley , Murray Christopher
Published: February 2014

Existing measures of help‐seeking focus on assessing attitudes and beliefs, rather than specific behaviors, toward help‐seeking. This study described the development of a self‐report measure of informal help‐seeking behaviors (HSB). Participants were 228 high school students (148 males, 80 females) with disabilities from four states. Factor analyses revealed three underlying factors, each addressing a different source of help: parent, peer, and teacher. The HSB had good internal reliability and moderate validity. Results from regression analyses suggested that help‐seeking behaviors toward parents and teachers contributed uniquely to students' self‐ratings of school bonding, life satisfaction, and career outcome expectations. Help‐seeking behaviors toward peers was a negative predictor of career outcome expectations. The value of the HSB as a research instrument was discussed.
Survey and analysis of simple sequence repeats (SSRs) present in the genomes of plant viroids
Authors: Qin Lü , Zhang Zhixiang , Zhao Xiangyan , Wu Xiaolong , Chen Yubao , Tan Zhongyang , Li Shifang
Published: February 2014

Extensive simple sequence repeat (SSR) surveys have been performed for eukaryotic prokaryotic and viral genomes, but information regarding SSRs in viroids is limited. We undertook a survey to examine the presence of SSRs in viroid genomes. Our results show that the distribution of SSRs in viroids may influence secondary structure, and that SSRs could play a role in generating genetic diversity. We also discuss the potential evolutionary role of repeated sequences in the viroid genome. This is the first report of SSR loci in viroids, and our study could be helpful in understanding the structure and evolution of viroid genomes.
Mutational and crystallographic analysis of l‐amino acid oxidase/monooxygenase from Pseudomonas sp. AIU 813: Interconversion between oxidase and monooxygenase activities
Authors: Matsui Daisuke , Im Do-Hyun , Sugawara Asami , Fukuta Yasuhisa , Fushinobu Shinya , Isobe Kimiyasu , Asano Yasuhisa
Published: February 2014

In this study, it was shown for the first time that l‐amino acid oxidase of Pseudomonas sp. AIU813, renamed as l‐amino acid oxidase/monooxygenase (l‐AAO/MOG), exhibits l‐lysine 2‐monooxygenase as well as oxidase activity. l‐Lysine oxidase activity of l‐AAO/MOG was increased in a p‐chloromercuribenzoate (p‐CMB) concentration‐dependent manner to a final level that was five fold higher than that of the non‐treated enzyme. In order to explain the effects of modification by the sulfhydryl reagent, saturation mutagenesis studies were carried out on five cysteine residues, and we succeeded in identifying l‐AAO/MOG C254I mutant enzyme, which showed five‐times higher specific activity of oxidase activity than that of wild type. The monooxygenase activity shown by the C254I variant was decreased significantly. Moreover, we also determined a high‐resolution three‐dimensional structure of l‐AAO/MOG to provide a structural basis for its biochemical characteristics. The key residue for the activity conversion of l‐AAO/MOG, Cys‐254, is located near the aromatic cage (Trp‐418, Phe‐473, and Trp‐516). Although the location of Cys‐254 indicates that it is not directly involved in the substrate binding, the chemical modification by p‐CMB or C254I mutation would have a significant impact on the substrate binding via the side chain of Trp‐516. It is suggested that a slight difference of the binding position of a substrate can dictate the activity of this type of enzyme as oxidase or monooxygenase.
Breakdown of the Bretherton law due to wall slippage
Authors: Li Yen-Ching , Liao Ying-Chih , Wen Ten-Chin , Wei Hsien-Hung
Published: February 2014

Against the common wisdom that wall slip plays only a minor role in global flow characteristics, here we demonstrate theoretically for the displacement of a long bubble in a slippery channel that the well-known Bretherton $2/3$ law can break down due to a fraction of wall slip with the slip length $\lambda $ much smaller than the channel depth $R$. This breakdown occurs when the film thickness $h_{\infty } $ is smaller than $\lambda $, corresponding to the capillary number $Ca$ below the critical value $Ca^{\ast } \sim (\lambda /R)^{3 / 2}$. In this strong slip regime, a new quadratic law $h_{\infty } /R \sim Ca^{2} (R/\lambda )^{2}$ is derived for a film much thinner than that predicted by the Bretherton law. Moreover, both the $2/3$ and the quadratic laws can be unified into the effective $2/3$ law, with the viscosity $\mu $ replaced by an apparent viscosity $\mu _{app}= \mu h_{\infty } /({\lambda } + h_{\infty })$. A similar extension can also be made for coating over textured surfaces where apparent slip lengths are large. Further insights can be gained by making a connection with drop spreading. We find that the new quadratic law can lead to $\theta _{d} \propto Ca^{1 / 2} $ for the apparent dynamic contact angle of a spreading droplet, subsequently making the spreading radius grow with time as $r \propto t^{1 / 8}$. In addition, the precursor film is found to possess $\ell _{f} \propto Ca^{ - 1 / 2}$ in length and therefore spreads as $\ell _{f} \propto t^{1 / 3}$ in an anomalous diffusion manner. All these features are accompanied by no-slip-to-slip transitions sensitive to the amount of slip, markedly different from those on no-slip surfaces. Our findings not only provide plausible accounts for some apparent departures from no-slip predictions seen in experiments, but also offer feasible alternatives for assessing wall slip effects experimentally.
Examination of the geographical variation in human West Nile virus: a spatial filtering approach
Authors: TEVIE J. , BOHARA A. , VALDEZ R. B.
Published: February 2014

This paper examines the importance of environmental factors (mosquito pools and home foreclosures) in human West Nile virus (WNV) transmission in California and Colorado. The role of environmental factors is investigated by applying an instrumental variable technique to a spatial filtering random-effects negative binomial model to correct for both spatial autocorrelation and endogeneity. The results suggest that mosquito pools and home foreclosures are significant in explaining the prevalence of human WNV. An innovative aspect of this research is that it emphasizes the role of home foreclosures in WNV transmission and in the allocation of resources. Knowledge of the factors associated with WNV prevalence is crucial for abatement of future outbreaks. The results suggest that more resources should be allocated to areas that have a high number of home foreclosures and mosquito pools for surveillance and mitigation of the disease.
Political Tolerance, Psychological Security, and Religion: Disaggregating the Mediating Influence of Psychological Security
Authors: Eisenstein Marie A. , Clark April K.
Published: February 2014

This research focuses on the variable “psychological security” as a mediating influence for religion, and its influence on political tolerance. While the composite variable of "psychological security" (typically measured by dogmatism, self-esteem, and trust) has been part of many studies of political tolerance, insufficient attention has been paid to the influence of these separate indicators. This is problematic because certain religious beliefs, practices, and/or affiliations may contribute differentially to the particular components of psychological security that are linked with greater political intolerance. So, we do not know “if” and “how” religion may influence these separate psychological security components or the mediating influence of these components in the religionpsychological security-political tolerance connection. The objective of this project is to “unpack” the unique influence of the psychological security components in our understanding of political tolerance and to assess the mediating influence of these same components on the relationship between religion and tolerance.
Imaging in living cells using νB–H Raman spectroscopy: monitoring COSAN uptake
Authors: Tarrés Màrius , Canetta Elisabetta , Viñas Clara , Teixidor Francesc , Harwood Adrian J.
Published: February 2014

The boron cluster containing molecules, COSAN and I2-COSAN, accumulate within living cells, and can be visualised by νB–H Raman microspectroscopy. This offers an unexplored means of cell labelling.
Intracellular pH-sensitive delivery CaCO3 nanoparticles templated by hydrophobic modified starch micelles
Authors: Ying Xiaoying , Shan Chunlei , Jiang Kuaikuai , Chen Zhong , Du Yongzhong
Published: February 2014

CaCO3 nanoparticles were prepared using starch–octanoic acid chemical conjugate micelle solution as a template to improve the acid pH sensitive release profile.
Varying numbers and positions of carboxylate groups on Ru dyes for dye-sensitized solar cells: uptake on TiO2, cell performance and cell stability
Authors: Hewat Tracy , McDonald Shane , Lee Jonathan , Rahman Mahfujur , Cameron Petra , Hu Fa-Chun , Chi Yun , Yellowlees Lesley J. , Robertson Neil
Published: February 2014

Varying the number and position of carboxylate groups on Ru(ii) dyes affects the efficiency, dye uptake, dye binding and stability of dye-sensitised solar cells.
Nanoscale structural disorder in manganese oxide particles embedded in Nafion
Authors: Chang Shery L. Y. , Singh Archana , Hocking Rosalie K. , Dwyer Christian , Spiccia Leone
Published: February 2014

High degree of structural disorders in birnessite phase particles in Nafion are responsible for high photo-electrochemical water-oxidation activity.
Investigation of the high-temperature redox chemistry of Sr2Fe1.5Mo0.5O6−δvia in situ neutron diffraction
Authors: Bugaris Daniel E. , Hodges Jason P. , Huq Ashfia , Chance W. Michael , Heyden Andreas , Chen Fanglin , Loye Hans-Conrad zur
Published: February 2014

The composition of Sr2Fe1.5Mo0.5O6−δ, a SOFC electrode material, is investigated by neutron diffraction in both highly oxidizing and reducing conditions, and correlated with measured physical properties.
Chemically stable magnetic nanoparticles for metal adsorption and solid acid catalysis in aqueous media
Authors: Okada T. , Takeda Y. , Watanabe N. , Haeiwa T. , Sakai T. , Mishima S.
Published: February 2014

Magnetically collectable and reusable particles for concentrating heavy metal ions and solid acid catalysis in aqueous media were developed.
π-Conjugation-interrupted hyperbranched polymer electrets for organic nonvolatile transistor memory devices
Authors: Lin Jinyi , Li Wen , Yu Zhenzhen , Yi Mingdong , Ling Haifeng , Xie Linghai , Li Shengbiao , Huang Wei
Published: February 2014

By means of the limited conjugation length, the intrinsic 3-dimensional conformations and the potential nanoporous structures, π-conjugation-interrupted hyperbranched polymers (CIHPs) were demonstrated as polymer electrets for the application of organic transistor memory devices.
Low-power photon upconversion in organic glasses
Authors: Vadrucci Roberto , Weder Christoph , Simon Yoan C.
Published: February 2014

Green-to-blue upconverting molecular glasses consisting of a metal octaethylporphyrin sensitizer and a diphenylanthracene derivative as an emitting matrix are reported.
Controlling uniformity of photopolymerized microscopic hydrogels
Authors: Park Sukho , Kim Dongshin , Ko Seong Young , Park Jong-Oh , Akella Sathish , Xu Bing , Zhang Ye , Fraden Seth
Published: February 2014

Unexpected non-uniform gelation generated by photopolymerization with uniform illumination is explained as a result of reaction–diffusion in a confined space.
Ru(ii)-catalyzed rearrangement of the allenic sulfide bearing propargyl moiety: efficient formation of benzene derivatives
Authors: Peng Lingling , Zhang Xiu , Ma Jie , Wang Jianbo
Published: February 2014

[RuCl2(p-cymene)]2 efficiently catalyzes the rearrangement of allenic sulfides bearing the propargyl moiety to afford 1,2,4-trisubstituted benzene derivatives.
A non-platonic M4L4 complex constructed using heterotopic ligands
Authors: Hall Gregory S. , Emerson Adrian J. , Turner David R.
Published: February 2014

An unusual, chloride-capped M4L4 complex has been prepared using heterotopic ligands with carboxylate and dipyridyl coordinating sites.
Are microorganisms indispensable in green microbial nanomaterial synthesis?
Authors: Liu Lihong , Shao Zongping , Ang Ha Ming , Tadé Moses O. , Liu Shaomin
Published: February 2014

Typical microbial synthesis relies heavily on microbial alchemy.