bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tsallis entropy in dual homogenization of random composites using the stochastic finite element method
Authors: Kamiński Marcin 
Published: August 2017

SummaryThis work concerns an application of the Tsallis entropy to homogenization problem of the fiber‐reinforced and also of the particle‐filled composites with random material and geometrical characteristics. Calculation of the effective material parameters is done with two alternative homogenization methods—the first is based upon the deformation energy of the Representative Volume Element (RVE) subjected to the few specific deformations, while the second uses explicitly the so‐called homogenization functions determined under periodic boundary conditions imposed on this RVE. Probabilistic homogenization is made with the use of three concurrent non‐deterministic methods, namely Monte‐Carlo simulation, iterative generalized stochastic perturbation technique as well as the semi‐analytical approach. The last two approaches are based on the Least Squares Method with polynomial basis of the statistically optimized order— this basis serves for further differentiation in the 10th‐order stochastic perturbation technique, while semi‐analytical method uses it in probabilistic integrals. These three approaches are implemented all as the extensions of the traditional Finite Element Method (FEM) with contrastively different mesh sizes, and they serve in computations of Tsallis entropies of the homogenized tensor components as the functions of input coefficient of variation.
Synthesis of PCL‐branched P(MMA‐co‐HEMA) to toughen electrospun PLLA fiber membrane
Authors: Jiang Suchen , Liu Huanchao , Zhang Xue , Ren Yajun , Cui Xinxiang , Song Xiaofeng 
Published: August 2017

Electrospun biodegradable fiber mesh is a promising alternative scaffold for delivering progenitor cells for repairing damaged or diseased tissue, but its cripple mechanical stability has not met the requirement of tissue engineering yet. In this work, the well‐defined poly(ε‐caprolactone)‐branched poly(methyl methacrylate‐co‐hydroxyethylmethacrylate) (PCL‐PMH) has been successfully synthesized to toughen electrospun poly(l‐lactide) (PLLA) fiber membrane. Characterization of the obtained nanofibrous meshes indicates that PCL‐PMH and PLLA can be well blended to make smooth fibers, and fibrous diameter vary little with blending PCL‐PMH. The aggregation state of two macromolecules is closely correlated with blend ratio, molecular structure, and molecular weight of PCL‐PMH, and only when PCL‐PMH and PLLA form good interfacial adhesion can PMH give full play to its potential for toughening the fiber membrane. The tensile strength and elongation at break of the blend are 6.20 MPa and 63.40% under the optimal conditions, respectively, and it also exhibits the representative feature of toughness materials. The blending fiber membrane is as no cytotoxic as original PLLA. This work will provide a new way for toughness of electrospun fiber membrane in practice.
The mechanical properties of damping rubber reinforced by Wrap Knitted Spacer Fabric
Authors: Li Qiuying , Wang Haoqiu , Yin Peng , Sun Lewen , Wu Chifei 
Published: August 2017

Damping rubber, which is a blend of chlorinated isobutylene isoprene rubber (CIIR) and micromolecule resins (petroleum resins or rosin resins), was impregnated onto Wrap Knitted Spacer Fabric (WKSF) through solution method in order to produce damping rubber/WKSF composites. CIIR‐grafted–(maleic anhydride) (abbreviated as CIIR‐g‐MAH) was synthesized and used as a novel compatibilizer for damping rubber/WKSF composites. The loss tangent factor (tan δ) values decreased and the tan δ peak moved to a lower temperature after WKSF was added. The tensile strength of the damping rubber was improved significantly with the skeleton structure of WKSF. The addition of CIIR‐g‐MAH increased the tensile strength further. Interfacial shear strength showed strong interactive interface between the matrix and the polyethylene terephthalate (PET) fiber of WKSF after the addition of CIIR‐g‐MAH. Scanning electron microscopy showed the morphology of the fracture surface and the interfacial compatibilization mechanism was investigated. POLYM. COMPOS., 39:4434–4441, 2018. © 2017 Society of Plastics Engineers
Aqueous self‐assembly of pullulan‐b‐poly(2‐ethyl‐2‐oxazoline) double hydrophilic block copolymers
Authors: Willersinn Jochen , Schmidt Bernhard V. K. J. 
Published: August 2017

ABSTRACTThe self‐assembly of a novel double hydrophilic block copolymer in water without the application of external triggers is described, namely pullulan‐b‐poly(2‐ethyl‐2‐oxazoline) (Pull‐b‐PEtOx). The biomacromolecules, Pull (8–38 kg mol−1), is modified and conjugated to biocompatible PEtOx (22 kg mol−1) via modular conjugation. Moreover, the molecular weight of the Pull blocks are varied to investigate the effect of molecular weight on the self‐assembly behavior. Spherical particles with sizes between 300 and 500 nm are formed in diluted aqueous solution (0.1–1.0 wt %) as observed via dynamic light scattering and static light scattering. Additionally, cryo scanning electron microscopy and laser scanning confocal microscopy are performed to support the finding from light scattering. The block ratio study shows an optimum ratio of Pull and PEtOx of 0.4/0.6 for self‐assembly in water in the concentration range of 0.1–1.0 wt %. At higher concentrations of 20 wt %, vesicular structures with sizes above 1 µm can be observed via optical microscopy. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3757–3766
Effect of nematic ordering on the elasticity and yielding in disordered polymeric solids
Authors: Giuntoli Andrea , Calonaci Nicola , Bernini Sebastiano , Leporini Dino 
Published: August 2017

ABSTRACTThe relation between elasticity and yielding is investigated in a model polymer solid by Molecular‐Dynamics simulations. By changing the bending stiffness of the chain and the bond length, semicrystalline and disordered glassy polymers — both with bond disorder — as well as nematic glassy polymers with bond ordering are obtained. It is found that in systems with bond disorder the ratio τY/G between the shear yield strength τY and the shear modulus G is close to the universal value of the atomic metallic glasses. The increase of the local nematic order in glasses leads to the increase of the shear modulus and the decrease of the shear yield strength, as observed in experiments on nematic thermosets. A tentative explanation of the subsequent reduction of the ratio τY/G in terms of the distributions of the per‐monomer stress is offered. © 2017 Wiley Periodicals, Inc. J. Polym. Sci. Part B: Polym. Phys. 2017, 55, 1760–1769
Influence of Nickel Catalyst Morphology on Layer‐Exchange‐Based Carbon Crystallisation of Ni/a‐C Bilayers
Authors: Janke Daniel , Hulman Martin , Wenisch Robert , Gemming Sibylle , Rafaja David , Krause Matthias 
Published: August 2017

Metal‐induced crystallisation with layer exchange is applied on Ni/C bilayer stacks deposited by three PVD techniques on SiO2. The layer stacks were deposited at room temperature by either ion beam sputtering, direct current magnetron sputtering or high‐power impulse magnetron sputtering. The influence of the Ni morphology on the layer exchange degree αLE and the resulting graphitic ordering is studied by atomic force microscopy, Rutherford backscattering spectrometry and Raman spectroscopy. The initial RMS roughness of the Ni top layer varied with the deposition technique by a factor of 20, from 0.3 to 6.1 nm.After annealing in UHV at up to 700 °C, layer exchange was observed for all samples. Still, the layer exchange degree was affected by the roughness of the initial bilayer stack. The highest value of 96% was achieved for magnetron‐sputtered samples, what is by ∼35% higher than for the initially roughest Ni surfaces. Raman spectroscopy showed the formation of graphitic carbon, characterised by a strong 2D line, for all three bilayer stacks. The degree of graphitic ordering increased with decreasing Ni surface roughness.
The Effects of Curcumin and Curcumin–Phospholipid Complex on the Serum Pro‐oxidant–Antioxidant Balance in Subjects with Metabolic Syndrome
Authors: Ghazimoradi Maryam , Saberi‐Karimian Maryam , Mohammadi Farzane , Sahebkar Amirhossein , Tavallaie Shima , Safarian Hamideh , Ferns Gordon A. , Ghayour‐Mobarhan Majid , Moohebati Mohsen , Esmaeili Habibollah , Ahmadinejad Malihe 
Published: August 2017

Metabolic syndrome (MetS) is defined by a clustering of metabolic and anthropometric abnormalities and is associated by an increased risk of cardiovascular disease. We have investigated the effect of curcumin supplementation on the serum pro‐oxidant–antioxidant balance (PAB) in patients with MetS. This double‐blind, randomized, placebo‐controlled trial was conducted over 6 weeks. Subjects (n = 120) were randomly allocated to one of three groups (curcumin, phospholipidated curcumin, and placebo). The curcumin group received 1 g/day of simple curcumin, the phospholipidated curcumin group received 1 g/day of phospholipidated curcumin (containing 200 mg of pure curcumin), and the control group received 1 g/day of placebo. Serum PAB was measured before and after the intervention (at baseline and at 6 weeks). Data analyses were performed using spss software (version 16.0). Serum PAB increased significantly in the curcumin group (p < 0.001), but in the phospholipidated curcumin group, elevation of PAB level was not significant (p = 0.053). The results of our study did not suggest any improvement of PAB following supplementation with curcumin in MetS subjects. Copyright © 2017 John Wiley & Sons, Ltd.
Pharmacological Evaluation of Gut Modulatory and Bronchodilator Activities of Achyranthes aspera Linn.
Authors: Rahman Hafiz Muhammad Abdur , Bashir Samra , Mandukhail Safur Rehman , Huda Sohaib , Gilani Anwarul Hassan 
Published: August 2017

Achyranthes aspera L. is traditionally used to relieve constipation, diarrhea, and asthma. Its crude extract (Aa.Cr) was evaluated through in vivo and ex vivo experiments to rationalize these medicinal uses of A. aspera and to provide their scientific basis. Aa.Cr, at 3 and 10 mg/kg, increased fecal output, similar to castor oil, whereas at 30, 100, 300, and 700 mg/kg, it protected against castor oil‐induced diarrhea in mice when administered orally. Aa.Cr caused spasmogenic effect on rabbit jejunum and guinea pig ileum preparations, which was partially inhibited by atropine while completely blocked by cyproheptadine preincubation. Aa.Cr also relaxed high K+ (80 mM)‐induced contraction in rabbit jejunum. Aa.Cr inhibited CCh (100 μg/kg)‐induced bronchospasm in rats, similar to aminophylline. Like dicyclomine, Aa.Cr relaxed high K+ and CCh (1 μM)‐induced contractions in guinea pig trachea and caused rightwards parallel shift of CCh concentration–response curves at the lower concentrations followed by non‐parallel shift at the higher concentrations. On activity‐directed fractionation, spasmogenic and spasmolytic activities of Aa.Cr were concentrated in aqueous and organic fraction, respectively. This study suggests the presence of dose‐specific laxative and antidiarrheal effects in A. aspera, possibly mediated through cyproheptadine‐sensitive receptors and dual cholinergic and calcium channel blockade, respectively. The latter combination is also a suggested mechanism underlying its bronchodilator effect. Copyright © 2017 John Wiley & Sons, Ltd.
Sampled‐data control of a class of uncertain switched nonlinear systems in nonstrict‐feedback form
Authors: Mao Jun , Guo Jian , Xiang Zhengrong 
Published: August 2017

SummaryThis paper investigates the stabilization problem of sampled‐data output feedback for a class of uncertain switched nonlinear systems in nonstrict‐feedback form. An observer is designed to estimate the unmeasured states, and a sampled‐data controller is obtained by discretizing the virtual controller that is constructed via the dynamic surface control method. It is proved that the designed sampled‐data controller can render all states of the resulting closed‐loop system to converge to a neighborhood of the origin for the arbitrary switching signal, and an allowable sampling period is also given. Finally, 2 examples are presented to illustrate the effectiveness of the proposed method.
Combining walking and relaxation for stress reduction—A randomized cross‐over trial in healthy adults
Authors: Matzer Franziska , Nagele Eva , Lerch Nikolaus , Vajda Christian , Fazekas Christian 
Published: August 2017

AbstractBoth physical activity and relaxation have stress‐relieving potential. This study investigates their combined impact on the relaxation response while considering participants' initial stress level.In a randomized cross‐over trial, 81 healthy adults completed 4 types of short‐term interventions for stress reduction, each lasting for 1 hr: (1) physical activity (walking) combined with resting, (2) walking combined with balneotherapy, (3) combined resting and balneotherapy, and (4) resting only. Saliva cortisol, blood pressure, state of mood, and relaxation were measured preintervention and postintervention. Stress levels were determined by validated questionnaires.All interventions were associated with relaxation responses in the variables saliva cortisol, blood pressure, state of mood, and subjective relaxation. No significant differences were found regarding the reduction of salivary cortisol (F = 1.30; p = .281). The systolic blood pressure was reduced best when walking was combined with balneotherapy or resting (F = 7.34; p < .001). Participants with high stress levels (n = 25) felt more alert after interventions including balneotherapy, whereas they reported an increase of tiredness when walking was combined with resting (F = 3.20; p = .044).Results suggest that combining physical activity and relaxation (resting or balneotherapy) is an advantageous short‐term strategy for stress reduction as systolic blood pressure is reduced best while similar levels of relaxation can be obtained.
Free‐Blockage Mesoporous Anticancer Nanoparticles Based on ROS‐Responsive Wetting Behavior of Nanopores
Authors: Cheng Yaya , Jiao Xiangyu , Xu Tailin , Wang Wenqian , Cao Yu , Wen Yongqiang , Zhang Xueji 
Published: August 2017

AbstractTo achieve an excellent delivery effect of drug, stimuli‐responsive nano “gate” with physical blockage units is usually constructed on the surface of the mesoporous silica nanocarriers (MSNs). In nature, the aquaporins in cell membrane can control the transport of water molecules by regulating the channel wettability, which is resulted from the conformational change of amino acids in the channel. Inspired by this phonomenon, herein a new concept of free‐blockage controlled release system is proposed, which is achieved by controlling the wettability of the internal surface of nanopores on MSNs. Such a new system is different from the physical‐blockage controlled release system, which bypasses the use of nano “gate” and overcomes the limitations of traditional physical blockage system. Moreover, further studies have shown that the system can selectively release the entrapped doxorubicin in human breast adenocarcinoma (MCF‐7) cells triggered by intracellular reactive oxygen species (ROS) but not in normalhuman umbilical vein endothelial cells (HUVECs) containing ROS with low levels. The wettability‐determined free‐blockage controlled release system is simple and effective, and it can also be triggered by intracellular biological stimuli, which provides a new approach for the future practical application of drug delivery and cancer therapy.
An empirical assessment of technical debt practices in industry
Authors: Codabux Zadia , Williams Byron J. , Bradshaw Gary L. , Cantor Murray 
Published: August 2017

AbstractContextTechnical debt refers to the consequences of taking shortcuts when developing software. These consequences can impede the software growth and have financial implications. The software engineering research community needs to explore technical debt further from a practitioner standpoint.ObjectiveThis study gathers insights from practitioners on key components of technical debt such as its definition, characterization, consequences, benefits, and how it is communicated.MethodWe conducted semi‐structured interviews with a convenience sample of 17 practitioners and a survey of 67 participants.ResultsDespite the lack of consensus, we identified the most commonly accepted definition, method to measure technical debt (as person hours), and method to reduce debt (by allocating time in iterations to address the debt). Defects were also identified as type of debt and the cost of technical debt is more than the cost to make changes to source code. Three distinct company profiles emerged.ConclusionDespite increasing research on technical debt, the field lacks consensus on its many facets. One interesting outcome of this study is how to assess the risks of technical debt by evaluating liabilities beyond costs of directly handling debt.
Validity evidence for a learning progression of scientific explanation
Authors: Yao Jian‐Xin , Guo Yu‐Ying 
Published: August 2017

AbstractProviding scientific explanations for natural phenomena is a fundamental aim of science; therefore, scientific explanation has been selected as one of the key practices in science education policy documents around the world. To further elaborate on existing educational frameworks of scientific explanation in K–12, we propose a learning progression of scientific explanation based on the Phenomenon‐Theory‐Data‐Reasoning (PTDR) framework. To examine the validation of the PTDR framework for scientific explanation and the learning progression based on it, we developed the Scientific Explanation Progression Assessment to investigate students’ performance (Grades 8–12 students, N = 4,554) on scientific explanations. A Rasch analysis and other statistical tests together indicated the validity of the PTDR framework for scientific explanation and the learning progression derived from this framework. We end with a discussion of the implications for future design of instruction and assessment. © 2017 Wiley Periodicals, Inc. J Res Sci Teach 55: 299–317, 2018
Advances in metabolome information retrieval: turning chemistry into biology. Part II: biological information recovery
Authors: Tebani Abdellah , Afonso Carlos , Bekri Soumeya 
Published: August 2017

AbstractThis work reports the second part of a review intending to give the state of the art of major metabolic phenotyping strategies. It particularly deals with inherent advantages and limits regarding data analysis issues and biological information retrieval tools along with translational challenges. This Part starts with introducing the main data preprocessing strategies of the different metabolomics data. Then, it describes the main data analysis techniques including univariate and multivariate aspects. It also addresses the challenges related to metabolite annotation and characterization. Finally, functional analysis including pathway and network strategies are discussed. The last section of this review is devoted to practical considerations and current challenges and pathways to bring metabolomics into clinical environments.
Direct observation of localized surface plasmon field enhancement by Kelvin probe force microscopy
Authors: Li Da-Bing , Sun Xiao-Juan , Jia Yu-Ping , Stockman Mark I , Paudel Hari P , Song Hang , Jiang Hong , Li Zhi-Ming 
Published: August 2017

AbstractA surface plasmon (SP) is a fundamental excitation state that exists in metal nanostructures. Over the past several years, the performance of optoelectronic devices has been improved greatly via the SP enhancement effect. In our previous work, the responsivity of GaN ultraviolet detectors was increased by over 30 times when using Ag nanoparticles. However, the physics of the SP enhancement effect has not been established definitely because of the lack of experimental evidence. To reveal the physical origin of this enhancement, Kelvin probe force microscopy (KPFM) was used to observe the SP-induced surface potential reduction in the vicinity of Ag nanoparticles on a GaN epilayer. Under ultraviolet illumination, the localized field enhancement induced by the SP forces the photogenerated electrons to drift close to the Ag nanoparticles, leading to a reduction of the surface potential around the Ag nanoparticles on the GaN epilayer. For an isolated Ag nanoparticle with a diameter of ~200 nm, the distribution of the SP localized field is located within 60 nm of the boundary of the Ag nanoparticle. For a dimer of Ag nanoparticles, the localized field enhancement between the nanoparticles was the strongest. The results presented here provide direct experimental proof of the localized field enhancement. These results not only explain the high performance of GaN detectors observed with the use of Ag nanoparticles but also reveal the physical mechanism of SP enhancement in optoelectronic devices, which will help us further understand and improve the performance of SP-based optoelectronic devices in the future.
Expression of Thyroid Hormone Responsive SPOT 14 Gene Is Regulated by Estrogen in Chicken (Gallus gallus)
Authors: Ren Junxiao , Xu Naiyi , Zheng Hang , Tian Weihua , Li Hong , Li Zhuanjian , Wang Yanbin , Tian Yadong , Kang Xiangtao , Liu Xiaojun 
Published: August 2017

AbstractThyroid hormone responsive spot 14 (THRSP) is a small nuclear protein that responds rapidly to thyroid hormone. It has been shown that THRSP is abundant in lipogenic tissues such as liver, fat and the mammary gland in mammals. The THRSP gene acts as a key lipogenic activator and can be activated by thyroid hormone triiodothyronine (T3), glucose, carbohydrate and insulin. Here we report that chicken THRSP is also abundant in lipogenic tissues including the liver and the abdominal fat, and its expression levels increased with sex maturation and reached the highest level at the peak of egg production. Structure analysis of the THRSP gene indicates that there is a conscious estrogen response element (ERE) located in the −2390 – −2402 range of the gene promoter region. Further studies by ChIP-qPCR proved that the ERα interacts with the putative ERE site. In addition, THRSP was significantly upregulated (P < 0.05) when chickens or chicken primary hepatocytes were treated with 17β-estradiol in both the in vivo and in vitro conditions. We therefore conclude that THRSP is directly regulated by estrogen and is involved in the estrogen regulation network in chicken.
Optical spin noise spectra of Rb atomic gas with homogeneous and inhomogeneous broadening
Authors: Ma Jian , Shi Ping , Qian Xuan , Shang Yaxuan , Ji Yang 
Published: August 2017

AbstractWe study the optical spin noise spectra of Rb atomic gas with different broadening mechanisms. The first is homogeneous broadening using 250 Torr nitrogen buffer gas, while the other mechanism is inhomogeneous broadening via the Doppler effect without buffer gas. Spin noise signals are measured by the typical spin noise spectroscopy geometry (single-pass geometry) and the saturated absorption spectroscopy geometry (double-pass geometry). In the homogeneously broadened system, the line shape of the optical spin noise spectra shows a pronounced dip that vanishes at the center of the band in both geometries. In the inhomogeneously broadened system, however, a peak in the single-pass geometry and a dip in the double-pass geometry at the band center are observed. The difference between the optical spin noise spectra from these two systems arises from their different level-broadening mechanisms.