bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional and structural assessment of patients with and without persistent pain after thoracotomy
Authors: Springer J.S. , Karlsson P. , Madsen C.S. , Johnsen B. , Finnerup N.B. , Jensen T.S. , Nikolajsen L.
Published: July 2016

Background

Persistent pain is frequent after thoracotomy, with a reported prevalence of up to 60%. It remains unclear why some patients develop pain, whereas others do not. We therefore examined patients with and without pain after thoracotomy to identify pathophysiological contributors to persistent pain.

Methods

Twenty patients with persistent pain, 12 patients without pain and 20 healthy controls underwent detailed functional and structural assessment including psychometric and neuropathic pain questionnaires, bedside examination for pinprick hyperalgesia and brush allodynia, quantitative sensory testing according to the protocol of the German Research Network on Neuropathic Pain, measurement of capsaicin‐evoked flare response, intradermal nerve density as determined by skin biopsies and laser‐ and heat‐evoked potentials.

Results

Bedside testing revealed evoked pain in 16 of 20 patients with pain, but only in 2 of 12 patients without pain (p < 0.001). Quantitative sensory testing showed increased mechanical pain sensitivity (p = 0.018) on the operated side in patients with pain, but there were no differences between the two patient groups with regard to intradermal nerve fibre density, area and flux following capsaicin application and laser‐ and heat‐evoked potentials.

Conclusion

Different and individual pathophysiological mechanisms of pain may obscure the clinical picture and thus preclude identification of a specific pain profile in patients with persistent post‐thoracotomy pain.

Significance

Evoked pain is more frequent in patients with pain. Assessment of intradermal nerve density, capsaicin‐induced flare response and contact and laser heat‐evoked potentials revealed no differences between pain patients and pain‐free patients.
Design of suitable carrier buffer for free‐flow zone electrophoresis by charge‐to‐mass ratio and band broadening analysis
Authors: Kong Fan‐zhi , Yang Ying , He Yu‐chen , Zhang Qiang , Li Guo‐qing , Fan Liu‐yin , Xiao Hua , Li Shan , Cao Cheng‐xi
Published: July 2016

In this work, charge‐to‐mass ratio (C/M) and band broadening analyses were combined to provide better guidance for the design of free‐flow zone electrophoresis carrier buffer (CB). First, the C/M analyses of hemoglobin and C‐phycocyanin (C‐PC) under different pH were performed by CLC Protein Workbench software. Second, band dispersion due to the initial bandwidth, diffusion, and hydrodynamic broadening were discussed, respectively. Based on the analyses of the C/M and band broadening, a better guidance for preparation of free‐flow zone electrophoresis CB was obtained. Series of experiments were performed to validate the proposed method. The experimental data showed high accordance with our prediction allowing the CB to be prepared easily with our proposed method. To further evaluate this method, C‐PC was purified from crude extracts of Spirulina platensis with the selected separation condition. Results showed that C‐PC was well separated from other phycobiliproteins that have similar physicochemical properties, and analytical grade product with purity up to 4.5 (A620/A280) was obtained.
Aluminum‐Ion Asymmetric Supercapacitor Incorporating Carbon Nanotubes and an Ionic Liquid Electrolyte: Al/AlCl3‐[EMIm]Cl/CNTs
Authors: Jiao Handong , Wang Junxiang , Tu Jiguo , Lei Haiping , Jiao Shuqiang
Published: July 2016

An aluminum‐ion asymmetric supercapacitor was assembled utilizing a cathode made of multi‐walled carbon nanotubes (MWCNTs) in an ionic liquid 1‐ethyl‐3‐methylimidazolium chloride ([EMIm]Cl)‐based electrolyte. Two types of energy‐storage mechanisms, that is, electrochemical double‐layer capacitance (adsorption/desorption of AlCl4− on the surface) and limited intercalation pseudocapacitance (intercalation/deintercalation of AlCl4− in the graphite layer) at low current density, were observed and characterized. Meanwhile, the specific capacitance and cyclic stability of this supercapacitor were also evaluated by using galvanostatically charging–discharging. The result demonstrates that the specific capacitance decreases with increasing current density, which corresponds to the two types of energy‐storage mechanisms of this device. The corresponding retention rate of this device after 3500 cycles at current density of 0.4 A g−1 was 82.4 %, which shows good cyclic stability.
Mechanical Behavior during Electrochemical and Mechanical Deactivation of an Aged Electrode in a Lithium‐Ion Pouch Cell
Authors: Shi Lei , Kunz Ulrich
Published: July 2016

The mechanical behavior of lithium‐ion battery electrodes that undergo a severe capacity decrease are investigated by monitoring the out‐of‐plane displacement on the external surface of a pouch cell. The capacity degradation does not decrease gradually as a function of time but exhibits distinct behaviors with different causes. These are electrochemical aging during cycling and mechanical injury caused by manufacture failure. In the former case, both the permanent evolution and the anomalous distribution of the displacement accompanied with a consistent decrease of the capacity are correlated to the local deterioration of the adhesion of the material layers. The mechanical injury accelerates the capacity decrease by destroying the electrode structure, which results in a sudden decrease of the surface displacement. If the displacement reaches its limit, only a dynamic fluctuation remains, which reflects the remaining electrochemical process at a low level. As a result, we conclude that the loss of electrical connectivity between the active material layer and the current collector is responsible for the severe capacity degradation. This effect is more pronounced on the anode than the cathode. Both electrochemical cycling and mechanical injury can result in the weakening of the adhesion of the anode material on the current collector.
Physical laboratory analyses of intergravel flow through brown trout redds (Salmo trutta fario) in response to coarse sand infiltration
Authors: Obruca Wolfgang , Hauer Christoph
Published: July 2016

In the spawning environment of salmonids, the quality of the intergravel flow is an essential abiotic requirement for the survival success of incubated embryos. As one of the most frequently investigated anthropogenic environmental impacts, the enhanced mobilization of fine sediments (<1 mm) and their entry into riverine ecosystems is considered as a major cause for the degradation of a variety of biological processes and habitats, including the spawning habitats of salmonids. In catchments draining crystalline bedrock, however, like the Bohemian Massif in the northern part of Austria, the excessive loading of river channels with coarse sand and fine gravel sediments (D = 1–10 mm) and less cohesive than fines is common as a consequence of altered catchment land use. Here, far less understanding exists of the mechanism and the possible implications of coarse sand infiltration on the functioning of the intergravel flow in salmonid redds. To investigate the intergravel flow hydraulics in response to coarse sand infiltration (D50 = 2 mm) in brown trout spawning redds (Salmo truttafario) under controlled conditions, a laboratory flume experiment with three infiltration scenarios was conducted: (1) no infiltration; (2) segmental infiltration; and (3) full section infiltration. A more than two times drop in the average intergravel flow velocity was documented from scenario 1 (5.85 cms−1) to scenario 2 (2.53 cms−1) and another clear reduction was seen from scenario 2 (2.53 cms−1) to scenario 3 (1.61 cms−1). Moreover, in scenario 3, a clear reduction of the intergravel flow distance traveled was observed. Based on the findings we conclude that future considerations regarding the sustainable catchment management of salmonid fisheries should include programs to reduce not only the excessive entry of fines, but, in the relevant catchments, also the entry of excessive coarse sand into the riverine ecosystem. Copyright © 2016 John Wiley & Sons, Ltd.
Heterogeneous Forecast Adjustment
Authors: Bruijn Bert De , Franses Philip Hans
Published: July 2016

There is ample empirical evidence that expert‐adjusted model forecasts can be improved. One way to potential improvement concerns providing various forms of feedback to the sales forecasters. It is also often recognized that the experts (forecasters) might not constitute a homogeneous group. This paper provides a data‐based methodology to discern latent clusters of forecasters, and applies it to a fully new large database with data on expert‐adjusted forecasts, model forecasts and realizations. For the data at hand, two clusters can clearly be identified. Next, the consequences of having clusters are discussed. Copyright © 2016 John Wiley & Sons, Ltd.
Dealing with daily challenges in dementia (deal‐id study): an experience sampling study to assess caregiver functioning in the flow of daily life
Authors: van Knippenberg R.J.M. , de Vugt M.E. , Ponds R.W. , Myin‐Germeys I. , van Twillert B. , Verhey F.R.J.
Published: July 2016

Objective

Accurate assessment of caregiver functioning is of great importance to gain better insight into daily caregiver functioning and to prevent high levels of burden. The experience sampling methodology (ESM) is an innovative approach to assess subjective experiences and behavior within daily life. In this study, the feasibility of the ESM in spousal caregivers of people with dementia was examined, and the usability of ESM data for clinical and scientific practice was demonstrated.

Methods

Thirty‐one caregivers collected ESM data for six consecutive days using an electronic ESM device that generated ten random alerts per day. After each alert, short reports of the caregiver's current mood state and context were collected. Feasibility was assessed by examining compliance and subjective experiences with the ESM. Usability was described using group and individual ESM data.

Results

Participants on average completed 78.8% of the reports. One participant completed less than 33% of the reports and was excluded from data analyses. Participants considered the ESM device to be a user‐friendly device in which they could accurately describe their feelings and experiences. The ESM was not experienced as too burdensome. Zooming in on the ESM data, personalized patterns of mood and contextual factors were revealed.

Conclusions

The ESM is a feasible method to assess caregiver functioning. In addition to standard retrospective measurements, it offers new opportunities to gain more insight into the daily lives of people with dementia and their caregivers. It also provides new possibilities to tailor caregiver support interventions to the specific needs of the caregiver. Copyright © 2016 John Wiley & Sons, Ltd.
Statistical inference of dynamic resting‐state functional connectivity using hierarchical observation modeling
Authors: Sojoudi Alireza , Goodyear Bradley G.
Published: July 2016

Spontaneous fluctuations of blood‐oxygenation level‐dependent functional magnetic resonance imaging (BOLD fMRI) signals are highly synchronous between brain regions that serve similar functions. This provides a means to investigate functional networks; however, most analysis techniques assume functional connections are constant over time. This may be problematic in the case of neurological disease, where functional connections may be highly variable. Recently, several methods have been proposed to determine moment‐to‐moment changes in the strength of functional connections over an imaging session (so called dynamic connectivity). Here a novel analysis framework based on a hierarchical observation modeling approach was proposed, to permit statistical inference of the presence of dynamic connectivity. A two‐level linear model composed of overlapping sliding windows of fMRI signals, incorporating the fact that overlapping windows are not independent was described. To test this approach, datasets were synthesized whereby functional connectivity was either constant (significant or insignificant) or modulated by an external input. The method successfully determines the statistical significance of a functional connection in phase with the modulation, and it exhibits greater sensitivity and specificity in detecting regions with variable connectivity, when compared with sliding‐window correlation analysis. For real data, this technique possesses greater reproducibility and provides a more discriminative estimate of dynamic connectivity than sliding‐window correlation analysis. Hum Brain Mapp 37:4566–4580, 2016. © 2016 Wiley Periodicals, Inc.
Informing etiologic research priorities for squamous cell esophageal cancer in Africa: A review of setting‐specific exposures to known and putative risk factors
Authors: McCormack V.A. , Menya D. , Munishi M.O. , Dzamalala C. , Gasmelseed N. , Leon Roux M. , Assefa M. , Osano O. , Watts M. , Mwasamwaja A.O. , Mmbaga B.T. , Murphy G. , Abnet C.C. , Dawsey S.M. , Schüz J.
Published: July 2016

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers in most Eastern and Southern African countries, but its etiology has been understudied to date. To inform its research agenda, we undertook a review to identify, of the ESCC risk factors which have been established or strongly suggested worldwide, those with a high prevalence or high exposure levels in any ESCC‐affected African setting and the sources thereof. We found that for almost all ESCC risk factors known to date, including tobacco, alcohol, hot beverage consumption, nitrosamines and both inhaled and ingested PAHs, there is evidence of population groups with raised exposures, the sources of which vary greatly between cultures across the ESCC corridor. Research encompassing these risk factors is warranted and is likely to identify primary prevention strategies.
Calcium intake and colorectal cancer risk: Results from the nurses' health study and health professionals follow‐up study
Authors: Zhang Xuehong , Keum NaNa , Wu Kana , Smith‐Warner Stephanie A. , Ogino Shuji , Chan Andrew T. , Fuchs Charles S. , Giovannucci Edward L.
Published: July 2016

The relationship between calcium intake and colorectal cancer (CRC) risk remains inconclusive. We conducted this study to evaluate whether the association between calcium intake and CRC risk differs by anatomic subsite and determine the dose–response relationship for this association, as well as assess when in carcinogenesis calcium may play a role. We assessed calcium intake every 4 years and followed 88,509 women (1980–2012) in the Nurses' Health Study and 47,740 men (1986–2012) in the Health Professionals Follow‐Up Study. We documented 3,078 incident CRC cases. Total calcium intake (≥1,400vs. <600 mg/d) was associated with a statistically significant lower risk of colon cancer (multivariable relative risk: 0.78, 95%CI: 0.65–0.95). Similar results were observed by different sources of calcium (from all foods or dairy products only). The inverse association was linear and suggestively stronger for distal colon cancer (0.65, 0.43–0.99) than for proximal colon cancer (0.94, 0.72–1.22,p‐common effects = 0.14). Additionally, when comparing different latencies, the overall pattern suggested that the inverse association appeared to be stronger with increasing latency and was strongest for intakes 12–16 years before diagnosis. Comparing total calcium intakes of ≥1,400vs. <600 mg/d for intake 12–16 y before diagnosis, the pooled RR (95% CIs) of CRC was 0.76 (0.64–0.91). Higher calcium intake was associated with a lower risk of developing colon cancer, especially for distal colon cancer. Overall inverse association was linear and did not differ by intake source. Additionally, calcium intake approximately 10 years before diagnosis appeared to be associated with a lower risk of CRC.
Ambiguity of Symmetry
Authors: Hargittai Istvan
Published: July 2016

Beyond the universality of the symmetry concept, there are different emphases on its application in different branches of science. Chemistry, being between particle physics and astrophysics, represents a bridge in, and a utilitarian approach to, the application of the symmetry concept, which has proved immensely fruitful in twentieth‐century science. Some pivotal discoveries, especially in structural chemistry, molecular biology, and materials science, emerged by relaxing some of the stipulations of the classical teachings about symmetry. This highly personal presentation relies on ideas expressed by a number of notable individuals in recent science, among them J. Desmond Bernal, Francis Crick, Ronald J. Gillespie, Aleksandr I. Kitaigorodskii, Alan L. Mackay, George A. Olah, Linus Pauling, Roger Penrose, Dan Shechtman, James D. Watson, Steven Weinberg, and Eugene P. Wigner.
Soy Reduces Bone Turnover Markers in Women During Early Menopause: A Randomized Controlled Trial
Authors: Sathyapalan Thozhukat , Aye Mo , Rigby Alan S , Fraser William D , Thatcher Natalie J , Kilpatrick Eric S , Atkin Stephen L
Published: July 2016

Menopausal estrogen loss leads to an increased bone loss. Soy isoflavones can act as selective estrogen receptor modulators, their role in bone turnover is unclear. The primary outcome was assessing changes in plasma bone turnover markers. The secondary outcomes were assessing changes in cardiovascular risk markers including insulin resistance, blood pressure, and lipid profile. We performed a double-blind randomized parallel study in which 200 women within 2 years after the onset of their menopause were randomized to 15 g soy protein with 66 mg isoflavone (SPI) or 15 g soy protein alone (SP), daily for 6 months. There was a significant reduction in type I collagen crosslinked beta C-telopeptide (βCTX) (bone-resorption marker) with SPI supplementation (0.40 ± 0.17 versus 0.15 ± 0.09 μg/L; p < 0.01) compared to SP supplementation (0.35 ± 0.12 versus 0.35 ± 0.13 μg/L; p = 0.92) after 6 months. There was also a significant reduction in type I procollagen-N-propeptide (P1NP) (bone formation marker) with SPI supplementation (50.5 ± 25.0 versus 34.3 ± 17.6 μg/L; p < 0.01), more marked between 3 and 6 months. Following SPI there was a significant reduction in fasting glucose, fasting insulin, insulin resistance, and systolic blood pressure whereas no significant changes in these parameters was observed with SP. There were no significant changes in fasting lipid profile and diastolic blood pressure with either preparation. There was a significant increase in TSH and reduction in free thyroxine (p < 0.01) with SPI supplementation though free tri-iodothyronine was unchanged. In conclusion, soy protein with isoflavones may confer a beneficial effect on bone health, analogous to the mode of action of antiresorptive agents, albeit to a less magnitude. There was a significant improvement of cardiovascular risk markers, but a significant increase in TSH and reduction in free thyroxine after SPI supplementation indicating a detrimental effect on thyroid function. © 2016 American Society for Bone and Mineral Research.
A Porphyrin‐Based Discrete Tetragonal Prismatic Cage: Host–Guest Complexation and Its Application in Tuning Liquid‐Crystalline Behavior
Authors: Yu Guocan , Ye Yang , Tong Zaizai , Yang Jie , Li Zhengtao , Hua Bin , Shao Li , Li Shijun
Published: July 2016

The host–guest complexation between a porphyrin‐based 3D tetragonal prism (H) and electron‐rich pyrene is investigated. This host–guest molecular recognition is further utilized to suppress the liquid‐crystalline behavior of a nematic molecule (G) containing cyanobiphenyl mesogens functionalized with a pyrenyl unit. Furthermore, coronene, with an increased number of π‐electrons, is used as a competitive guest to recover the liquid‐crystalline behavior of G. This supramolecular approach provides a glimpse of the new possibilities to modulate the structures of the mesophases.

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Integrating Graphene and C60 Into TiO2 Nanofibers via Electrospinning Process for Enhanced Conversion Efficiencies of DSSCs
Authors: Asmatulu Ramazan , Shinde Manish A. , Alharbi Abdulaziz R. , Alarifi Ibrahim M.
Published: July 2016

Electrospun TiO2 nanofibers incorporated with graphene and C60 nanoparticles at 0, 1, 2, 4, and 8 wt.% were produced using poly (vinyle acetate), dimetylfomamide, and titanium (IV) isopropoxide. The resultant nanofibers were heat treated at 300 °C for 2 hrs in a standard oven to remove all the organic parts of the nanofibers, and then further heated up to 500 °C in Ar for additional 12 hrs to crystallize the TiO2 nanofibers. For the graphene and C60 containing nanofibers, two steps annealing at 300 °C (air) and 500 °C (Ar) were conducted to eliminate the decomposition processes of the graphene and C60 in the TiO2 nanofibers. SEM, TEM and XRD studies were conducted on the samples. The results showed that graphene and C60 were well integrated in the nanofiber structures. The TiO2 nanofibers with the inclusions were mixed in a solution to form a paste, which was then applied on a conductive glass after the TiCl4 solution treatments to make various dye sensitized solar cells (DSSCs). This technique enables creation of solar cells with variable thicknesses of 7 µm to 45 µm. The effects of the manufacturing technique, thickness of the paste, different percentages of graphene and C60 nanoparticles on overall efficiency of the solar cell were studied in detail. The test studies indicated that in the presence of graphene and C60, the DSSC efficiency increased more than 50%. The present study may guide some of the scientists and engineers to tailor the energy band gap structures of the semiconductor materials for different industrial applications, including DSSCs, as well as water splitting, catalyst, Li‐ion batteries, and fuel cells.
The Influence of Biobased Olegomeric Diisocyanate on Thermal and Mechanical Properties of Poly(3‐hydroxybutyrate)
Authors: Reddy Chaganti Srinivasa , O’ Connor Kevin , Babu P Ramesh
Published: July 2016

In the present work, poly (3‐hydroxybutyrate) (PHB) blends were prepared by melt blending with biobased oligomeric diisocyanate synthesised from hexamethelene diisocyanate (Tolonate XFLO100 (TXF100)). PHBTXF100 blends with four different weight fraction (10, 15, 20 and 25 phr) of TXF100 were prepared and characterized for mechanical, thermal and thermomechanical properties. Strain at break and tensile toughness of PHBTXF10025 blend were improved by 200% and 193%, respectively. PHBTXF100 blends showed a broad glass transition temperature with a decreased onset temperature compared to PHB. PHBTXF100 blends exhibited low crystallinity than PHB, and was further decreased with an increased weight fraction of TXF100. Elastic and storage moduli PHBTXF100 blends were decreased compared to PHB, and correlated to their low degree of crystallinity. The changes in mechanical properties of PHBTXF100 blends were mainly due to efficient weakening of intermolecular interactions in the amorphous regions of PHB, and also a slight decrease in crystalline order of PHB.
Novel Chart for Representation of Material Performance and Reliability
Authors: Lanyi Franz J. , Kunzelmann Peter , Schubert Dirk W.
Published: July 2016

In modern industrial production lines various process and material parameters determine the properties of the final product. Thus, a process optimization procedure has to take into account a large design space containing several parameters. As a consequence, the evaluation of the influence of single process parameters on the final product properties can be quite complicated. Usually a certain property of a product, for example the mechanical strength, has to satisfy a defined specification. In terms of quality control not only the performance of the material but also the reliability of the specified values has to be considered. The Weibull statistic gives an interesting approach to evaluate both, material's performance and reliability. Regarding the mechanical properties e.g. in terms of the stress at break σb the Weibull analysis leads to a characteristic failure constant σb,0 at which 63.2 % of the samples will break. Additionally, the Weibull modulus m can be regarded as a measure for the width of the distribution of the measuring results. High values of m represent a narrow distribution and thus a better reliability. Moreover, the Weibull modulus m is independent of the absolute value of the measuring data. Therefore, it is possible to compare samples produced under different conditions. The standard deviation and the interquartile range are often used to quantify the scatter of empirical data. It is shown within this work that the Weibull modulus m can be a more precise discriminator for the evaluation of the reliability because it is rather stable against outlaying values. As an example this study concentrates on the mechanical properties of melt spun fibres consisting of blends from polypropylenes with different molar masses produced under various process conditions. This work presents a novel chart which allows one to compare different samples on the basis of the Weibull statistics whereat the Weibull modulus m is plotted over σb,0. Defining a reference material, the m‐σb,0‐map can be split into quadrants, whereat each quadrant designates an improvement or worsening of material's performance and reliability with respect to the reference. An evaluation in terms of performance and reliability of great sets of data is easily applicable. It will be shown that the Weibull statistic can also be applied to Young's Modulus, the elongation at break and the tensile energy absorption.
Biporous Crosslinked Polymers With Controlled Pore Size and Connectivity
Authors: Ly Hai Bang , Halbardier Lucile , Grande Daniel
Published: July 2016

A critically selected overview of different parameters affecting the porous features of doubly porous polymeric materials based on poly(2‐hydroxyethyl methacrylate) (PHEMA) and designed via a double porogen approach is addressed. A careful investigation was undertaken so as to highlight the main advantages of the proposed double porogen approach which relied on the distinct and independent control of both porosity levels, i.e. nano‐ and macro‐porosity. The nanoporosity level was produced via a phase separation phenomenon that occurred during the polymerization process in the presence of a porogenic solvent. To generate an interconnected macroporosity, two straightforward and versatile strategies were implemented through the use of sodium chloride (NaCl) macro‐sized particles. They involved the sintering of NaCl particles prior to the generation of PHEMA‐based networks. NaCl particles were fused through two different methods, either by sintering at 730 °C or by Spark Plasma Sintering. Upon porogen removal, doubly porous PHEMA‐based materials were obtained with macropores having NaCl particle imprints in the 100 μm order of magnitude, while the second porosity level laid within the 0.1–1 μm orders of magnitude, as evidenced by mercury intrusion porosimetry and scanning electron microscopy.
Binary and Ternary Blends of Polypropylene Types – Influence on the Homogeneity of Biaxial‐Oriented Films
Authors: Schubert Dirk W. , Kaschta Joachim , Seidl Stephan , Kunzelmann Peter
Published: July 2016

Biaxial‐oriented polypropylene (BOPP) is one of the most used materials for industrial films and food packaging. In terms of environmental and economic issues, the reduction of the film thickness, increasing the homogeneity, enhancing the process efficiency and stability are in the focus of this work. A systematic investigation on the biaxial stretching process is presented in this study. Therefore, two commercial linear polypropylenes with different molar masses and a commercial long‐chain‐branched polypropylene were used to obtain binary and ternary blends to adjust the elongation behavior on the molecular level. The blending was carried out using a cast film process on a twin‐screw extruder. The cast films obtained, were investigated before and after biaxial stretching. The thickness distribution of the films, were used as a measure of the film homogeneity, before and after the film stretching process. It turns out that casting and biaxial stretching are competing steps with respect to the film homogeneity. The casting step is dominated by the extrusion behavior of the blends. With increasing amount of the long‐chain branched material extrusion flow instabilities appear leading to an irregular surface and to a poor film homogeneity. Contrarily, long‐chain branches promote a more homogeneous deformation during the biaxial stretching inducing strain hardening which leads to a self‐healing effect and thus to an improved film homogeneity. The homogeneity of the final stretched film depends on both, casting and stretching. Therefore, a desirable polymer blend recipe with a medium amount of long‐chain branches is revealed for the stretched film.
Contribution of Fiber Undulation to Mechanics of Three‐Dimensional Collagen‐I Gel
Authors: Lin Shengmao , Gu Linxia
Published: July 2016

The collagen‐I gel is extensively used as a scaffold material in tissue engineering due to its ability to mimic the extracellular matrix (ECM). In this study, the mechanics of collagen‐I gel is investigated using a numerical model of three‐dimensional collagen network. The resulted mechanical behavior was validated against the published experimental data. Results illustrated that fiber alignment was dominated in the low strain region, and its transition to stretching dominated phenomena at higher strain led to the strain stiffening of collagen gel. The collagen undulation at the microscopic level was found to delay the initiation of strain stiffening.
Computational model coupling mode II discrete fracture propagation with continuum damage zone evolution
Authors: Jin Wencheng , Xu Hao , Arson Chloé , Busetti Seth
Published: July 2016

We propose a numerical method that couples a cohesive zone model (CZM) and a finite element‐based continuum damage mechanics (CDM) model. The CZM represents a mode II macro‐fracture, and CDM finite elements (FE) represent the damage zone of the CZM. The coupled CZM/CDM model can capture the flow of energy that takes place between the bulk material that forms the matrix and the macroscopic fracture surfaces. The CDM model, which does not account for micro‐crack interaction, is calibrated against triaxial compression tests performed on Bakken shale, so as to reproduce the stress/strain curve before the failure peak. Based on a comparison with Kachanov's micro‐mechanical model, we confirm that the critical micro‐crack density value equal to 0.3 reflects the point at which crack interaction cannot be neglected. The CZM is assigned a pure mode II cohesive law that accounts for the dependence of the shear strength and energy release rate on confining pressure. The cohesive shear strength of the CZM is calibrated by calculating the shear stress necessary to reach a CDM damage of 0.3 during a direct shear test. We find that the shear cohesive strength of the CZM depends linearly on the confining pressure. Triaxial compression tests are simulated, in which the shale sample is modeled as an FE CDM continuum that contains a predefined thin cohesive zone representing the idealized shear fracture plane. The shear energy release rate of the CZM is fitted in order to match to the post‐peak stress/strain curves obtained during experimental tests performed on Bakken shale. We find that the energy release rate depends linearly on the shear cohesive strength. We then use the calibrated shale rheology to simulate the propagation of a meter‐scale mode II fracture. Under low confining pressure, the macroscopic crack (CZM) and its damaged zone (CDM) propagate simultaneously (i.e., during the same loading increments). Under high confining pressure, the fracture propagates in slip‐friction, that is, the debonding of the cohesive zone alternates with the propagation of continuum damage. The computational method is applicable to a range of geological injection problems including hydraulic fracturing and fluid storage and should be further enhanced by the addition of mode I and mixed mode (I+II+III) propagation. Copyright © 2016 John Wiley & Sons, Ltd.
Delayed gastric emptying as a proposed mechanism of action during intragastric balloon therapy: Results of a prospective study
Authors: Gómez Victoria , Woodman George , Abu Dayyeh Barham K.
Published: July 2016

Objective

The effects of intragastric balloon (IGB) therapy on gastric emptying (GE) and weight loss remain to be fully understood. The effects of IGB on GE were investigated in this study.

Methods

This was a single‐center, randomized, controlled study in which subjects with obesity either underwent IGB placement or were matched controls. IGB was removed at 6 months. GE was measured at baseline and at weeks 0, 8, 16, 27, and 39. Percent total body weight loss (%TBWL) was measured at 6 and 12 months.

Results

Twenty‐nine subjects with obesity were enrolled; 15 were randomized to IGB placement and 14 to control. Two subjects had the IGB removed early. At baseline, 1‐ and 2‐h gastric retention values were comparable between the groups but increased in the IGB group at weeks 8 and 16 (during IGB treatment) and then returned to baseline levels at 27 and 39 weeks. A greater increase in gastric retention from baseline to 8 weeks was associated with higher %TBWL.

Conclusions

GE in subjects with IGB is delayed but returns to normal after IGB removal. Greater changes in increased gastric retention were associated with greater %TBWL. Altering gastric motility is a significant mechanism of action by which the IGB results in weight loss.
Comparability of the age and sex distribution of the UK Clinical Practice Research Datalink and the total Dutch population
Authors: de Jong Roy G.P.J. , Gallagher Arlene M. , Herrett Emily , Masclee Ad A.M. , Janssen‐Heijnen Maryska L.G. , de Vries Frank
Published: July 2016

Purpose

The UK Clinical Practice Research Datalink (CPRD) is increasingly being used by Dutch researchers in epidemiology and pharmacoepidemiology. It is however unclear if the UK CPRD is representative of the Dutch population and whether study results would apply to the Dutch population. Therefore, as first step, our objective was to compare the age and sex distribution of the CPRD with the total Dutch population.

Methods

As a measure of representativeness, the age and sex distribution of the UK CPRD were visually and numerically compared with Dutch census data from the StatLine database of the Dutch National Bureau of Statistics in 2011.

Results

The age distribution of men and women in the CPRD population was comparable to the Dutch male and female population. Differences of more than 10% only occurred in older age categories (75+ in men and 80+ in women).

Conclusions

Results from observational studies that have used CPRD data are applicable to the Dutch population, and a useful resource for decision making in the Netherlands. Nevertheless, differences in drug exposure likelihood between countries should be kept in mind, as these could still cause variations in the actual population studied, thereby decreasing its generalizability. Copyright © 2016 John Wiley & Sons, Ltd.
Effect of bromine substituent on optical properties of aryl compounds
Authors: Zhang Chao‐Zhi , Li Ting , Yuan Yang , Gu Cheng‐Yue , Niu Meng‐Xiao , Cao Hui
Published: July 2016

Substituents significantly affect optical properties of organic compounds. In this study, a series of organic compounds were synthesized. Ultraviolet‐visible and cyclic voltammetry spectra were determined. The relationships between the number of π electron in an aryl ring and the redshift (and molecular orbital energy levels) were studied. To investigate mechanisms of the bromine substituent effects, theoretical calculations were carried out. Ultraviolet‐visible spectra of bromine‐containing compounds exhibit obvious redshifts (0.04‐0.17 eV) of the maximal absorption wavelengths and enhanced absorbance (11%‐57%) compared with corresponding reference compounds. The lowest unoccupied and highest occupied molecular orbital energy levels of compounds containing bromine substituents are 0.05 to 0.60 and 0.02 to 0.40 eV lower than that of corresponding reference compounds. On the whole, the redshifts and the reduced molecular orbital energy levels caused by bromine substituent decrease with the increase in the number of π electron in an aryl ring. The effects would be attributed to strong p‐π conjugation between p electron in the bromine substituent and π electrons in aryl rings. Therefore, this paper suggests a useful way for tuning optical absorption and molecular orbital energy levels of aryl compounds.
Modeling of radiation‐induced sink evolution in 6061 aluminum alloy in nuclear reactors
Authors: Choi Sang Il , Lee Gyeong‐Geun , Kwon Junhyun , Kim Ji Hyun
Published: July 2016

The objective of this study is a detailed analysis of the radiation effects on sink generation and growth in order to understand the phenomenon of irradiation hardening of 6061 aluminum alloy in research reactor conditions. In order to have a fundamental understanding, various sink behavior characteristics such as size and number density of dislocation loop, void, and precipitation were calculated and examined. Thereafter, theoretical assessment of various sink effects on irradiation hardening was conducted based on the mean field rate theory (MFRT). Dislocation loop, void, and precipitation were examined by defect flux. For the quantitative analysis of radiation‐induced degradation, change in sink size was calculated using number density. 6061 Alloy showed great dependence on precipitation generation and growth. However, dislocation loop and void did not have any significant effect on irradiation hardening. Finally, the behavior of sinks was compared with the experimental results for validation.
Temperature dependency of Cu/Zn ordering in CZTSe kesterites determined by anomalous diffraction
Authors: Többens Daniel M. , Gurieva Galina , Levcenko Sergiu , Unold Thomas , Schorr Susan
Published: July 2016

Low‐temperature cation ordering is emerging as a critical factor limiting the efficiency of CZTSSe kesterite photovoltaic materials. By means of direct determination of the site occupancies from anomalous X‐ray powder diffraction data at the Cu‐ and Zn‐absorption edges, the ordering of Cu+ and Zn2+ in B‐type Cu2ZnSnSe4 (CZTSe) kesterite upon annealing at temperatures below 203 (6) °C is demonstrated. Anomalous X‐ray diffraction on the Cu‐ and Zn‐K absorption edges allows determination of the distribution of isoelectric Cu1+ and Zn2+ over the crystallographic sites in a B‐type CZTSe kesterite (Cu1.949(20)Zn1.059(10)Sn0.983(10)Se4) powder. By Rietveld refinement the quantitative determination of both Cu‐ and Zn‐occupancy for all relevant sites is achieved. From this, the temperature dependency of a structure‐based, quantitative order parameter is determined. The critical temperature of the phase transition is confirmed at 203 (6) °C. The ordering mechanism is in agreement with a transition from disordered to ordered kesterite. The photoluminescence band maximum shows a closely related temperature dependency, directly demonstrating the effect of cation ordering on the optical properties of CZTSe.
Photodegradation of cyprodinil under UV–visible irradiation – chemical and toxicological approaches
Authors: Nicol Edith , Chayata Houda , Genty Christophe , Bouchonnet Stéphane , Bourcier Sophie
Published: July 2016

Rationale

Cyprodinil is a fungicide active on grapes, strawberries, tomatoes, and many other fruits. Under UV–visible irradiation, it undergoes photodegradation through various processes to form transformation products (TPs) whose structures and potential toxicities are unknown. The structures of the TPs were elucidated by comparing the photodegradation of cyprodinil and cyprodinil‐D5. The potential toxicities of these compounds were compared with that of cyprodinil.

Methods

Aqueous solutions of cyprodinil were irradiated in a reactor equipped with a mercury vapor lamp. Analyses were carried out using high‐performance liquid chromatography coupled to a quadrupole time‐of‐flight (QTOF) mass spectrometer or to a SolarixXR 9.4 Tesla Fourier transform (FT) mass spectrometer. High‐resolution mass measurements, MS/MS and isotopic labeling experiments allowed structural elucidation of the cyprodinil TPs. The toxicities were estimated by three tests in silico using the TEST software and in vitro bioassays using Vibrio fischeri bacteria. These bioassays were carried out on irradiated solution for several exposure times and non‐irradiated solutions.

Results

The structures of 19 photoproducts were characterized by LC/HRMS/MS after 4 h of irradiation of a cyprodinil aqueous solution. The use of cyprodinil‐D5 allowed the TPs to be characterized with more confidence. Knowing the structure of the TPs allows the estimation of their potential toxicities by in silico tests. Most of the photoproducts are potentially more toxic than the parent compound, based on the oral rat LD50 values, and most of them might induce more developmental and mutagenic toxicities. In vitro assays on Vibrio fischeri bacteria showed that the global ecotoxicity of the cyprodinil solution significantly increases with irradiation time.

Conclusions

Structures of photoproducts were characterized after irradiation of a cyprodinil aqueous solution combining LC/HRMS, LC/HRMS/MS and the use of a labeled compound. Their formations imply several photodegradation reactions, namely direct bond cleavages, cyclization, isomerization and hydroxylation. Most of the TPs exhibit a toxicity significantly higher than that of the parent molecule. Copyright © 2016 John Wiley & Sons, Ltd.
Experimental investigation of dry mechanical beam–column joints for precast concrete based frames
Authors: Nzabonimpa J.D. , Hong Won‐Kee , Park Seon‐Chee
Published: July 2016

This paper proposes dry mechanical beam–column joints for fully restrained moment connections of concrete components. This novel joint can be used for reinforced concrete precast frames and steel–concrete composite precast frames. The new dry mechanical joint consists of extended steel plates with bolts designed to transfer tension and compression forces, providing fully restrained moment connections at the beam–column joint. The extended end plate with bolts introduced for column‐beam joint assembly was originally used in the steel moment frame, as introduced in AISC 358. This study developed similar but unique mechanical joint details for concrete frames in order to provide fully restrained moment connections for both steel–concrete composite precast frames and reinforced concrete precast frames. Experimental and analytical investigations were performed to verify the structural behavior of fully restrained moment connections for concrete components in order to identify the parameters that influence the structural behavior of dry mechanical moment concrete connections. These connections are expected to be used in modular offsite construction for buildings and heavy industrial plants. Copyright © 2016 John Wiley & Sons, Ltd.
Role of NF‐κB activation and Th1/Th2 imbalance in pulmonary toxicity induced by nano NiO
Authors: Chang Xuhong , Zhu An , Liu Fangfang , Zou Lingyue , Su Li , Li Sheng , Sun Yingbiao
Published: July 2016

With the progress of nanotechnology, nano nickel oxide (NiO) has been extensively used as sensors, battery electrodes, catalysts, and cosmetics. Previous researches verified that nano NiO could exert pulmonary toxicity, but its mechanism was unclear. To shed light upon this, the role of nuclear factor‐κB (NF‐κB) activation and Th1/Th2 imbalance were to explore in pulmonary damage induced by nano NiO. Male Wistar rats were randomized into control group, nano NiO groups (0.015, 0.06, and 0.24 mg kg−1) and micro NiO group (0.024 mg kg−1) and treated by intratracheal instillation twice a week for 6 weeks. The results showed that the abnormal changes induced by nano NiO were found on indicators of nitrative stress (NO, TNOS, and iNOS), inflammatory cytokines (TNF‐α, IL‐2, and IL‐10) and cytokine‐induced neutrophil chemoattractants (CINC‐1, CINC‐2αβ, and CINC‐3) in lung tissue. In addition, nano NiO instillation induced the upregulated mRNA and protein expression of NF‐κB, inhibitor of κB kinase‐α (IKK‐α) and nuclear factor‐inducing kinase (NIK). The protein content of GATA‐3 increased as well as T‐bet decreased in nano NiO groups, and the ratio of T‐bet/GATA‐3, as a key evaluation indicator of Th1/Th2 balance, was lower than the control group. The findings indicated that nano NiO could enhance the nitrative stress and inflammatory response in lung tissue, and its mechanism was related to the NF‐κB activation and Th1/Th2 imbalance. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1354–1362, 2017.
Identifying Needs: a Qualitative Study of women's Experiences Regarding Rapid Genetic Testing for Hereditary Breast and Ovarian Cancer in the DNA BONus Study
Authors: Augestad Mirjam Tonheim , Høberg‐Vetti Hildegunn , Bjorvatn Cathrine , Sekse Ragnhild Johanne Tveit
Published: July 2016

Genetic testing for hereditary breast and ovarian cancer is increasingly being offered in newly diagnosed breast and ovarian cancer patients. This genetic information may influence treatment decisions. However, there are some concerns that genetic testing offered in an already vulnerable situation might be an extra burden to these women. The aim of this study was to explore the experiences of women who had been offered and accepted genetic testing when newly diagnosed with breast or ovarian cancer. Four semi‐structured focus‐group interviews were conducted with 17 women recruited from a Norwegian multicenter study. The material was condensed, and conventional qualitative analysis was used to identify patterns in the participants’ descriptions. Three core themes were identified: 1) being “beside oneself” 2) altruism and ethical dilemmas 3) the need for support and counselling to assist the decision process. The present study indicates that women who are offered genetic testing when newly diagnosed with breast or ovarian cancer want a consultation with a health professional. Personalized support and counselling might empower women to improve their ability to manage and comprehend this overwhelming situation, and find meaning in this experience.
Ce1−x
Sm
x
O2−x/2—A novel type of ceramic material for thermal barrier coatings
Authors: Chen Xiao-ge , Zhang Haoming , Zhang Hong-song , Zhao Yong-de , Li Gang
Published: July 2016

In this study, Ce1−x
Sm
x
O2−x/2 ceramics were synthesized by sol–gel route and solid state sintering method. The phase structure was analyzed by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and Raman spectroscopy. The morphologies of the synthesized powders and the corresponding bulk samples were observed using scanning electron microscopy (SEM). Their thermal diffusivities and thermal expansion coefficients were measured by the laser-flash method and the pushing-rod method, respectively. Results show that pure Ce1−x
Sm
x
O2−x/2 powders with single fluorite structure are synthesized successfully, and their microstructures of the corresponding bulk samples are very dense. With the increase of Sm2O3 content, their thermal expansion coefficients decrease due to the higher electro-negativity of Sm3+ ions as compared with that of Ce4+ ions. Their thermal conductivities at 1000 °C lie in the range of 1.62–2.02 W/(m·K) due to the phonon scattering caused by the substituted atoms and oxygen vacancies. The Ce1−x
Sm
x
O2−x/2 ceramics can be used as ceramic candidates for novel thermal barrier coatings (TBCs).