bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance analysis of multiuser selection diversity in SIMO spectrum sharing systems
Authors: Aghazadeh Behnam , Torabi Mohammad
Published: August 2017

In this paper, a performance analysis is presented for user selection schemes in a single‐input multiple‐output spectrum sharing system. In the considered system, multiple secondary users try to use the licensed spectrum of a primary user in an opportunistic manner, in which an interference constraint for the primary user is satisfied. In this paper, we first use 2 conventional user selection schemes for single‐input multiple‐output spectrum sharing system and analyze the system performance for each scheme. We then propose a new user selection scheme that can overcome the limitations of those 2 conventional user selection schemes. As for the performance analysis, the average channel capacity, the outage probability, and the bit error rate performances of the system using the presented user selection schemes are analyzed and mathematical closed‐form expressions for the outage probability are derived. The performances of the system are evaluated using the derived mathematical formulas in different cases. In addition, Monte Carlo simulation results are also provided to show the accuracy and correctness of the performed analysis.
Forest Governance without Transparency? Evaluating state efforts to reduce deforestation in the Brazilian Amazon
Authors: Bizzo Eduardo , Michener Gregory
Published: August 2017

Over 60% of the Amazon basin is contained within nine federal Brazilian states. How transparent are state‐level governments about implementing and enforcing deforestation reduction policies? Advocates and officials can only influence forest conservation outcomes to the extent that they have information about the actions – the inputs and outputs – of front‐line local actors. Leveraging a recently adopted freedom of information (FOI) law, this paper evaluates how well governments comply with website‐based disclosure requirements (active transparency), and how effectively they respond to FOI requests (passive transparency) on the implementation and enforcement of deforestation reduction policies. By focusing on how subnational administrations disclose accountings of forest governance – the inputs and outputs of governance – the current study complements an already extensive body of scholarship on central government monitoring of forest cover – the transparency of outcomes. Comparing our results with an original database of transparency evaluations from Brazil, we find extremely low levels of compliance with FOI obligations. We do find, however, that government agencies possessing electronic FOI platforms, which help applicants send requests and appeals and accompany responses, fare better than those without. This and other findings have implications for the design of transparency systems, while global results speak to the policy challenges of federalism, especially dilemmas of subnational policy enforcement. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Behavioral protective factors of increased depressive symptoms in community‐dwelling older adults: A prospective cohort study
Authors: Uemura Kazuki , Makizako Hyuma , Lee Sangyoon , Doi Takehiko , Lee Songchul , Tsutsumimoto Kota , Shimada Hiroyuki
Published: August 2017

Background

It remains unclear what kinds of behavior prevent the development of geriatric depression. This study aimed to elucidate behavioral predictors of increased depressive symptoms in older adults focusing on gender differences.

Methods

A total of 3106 community‐dwelling older people aged older than or equal to 65 years without depressive symptoms at baseline participated. The 15‐item Geriatric Depression Scale was used to assess depressive symptoms with a score of 6 or more at baseline and 15 month follow‐up. Behavioral status was investigated by using dichotomous questions about the aspects of physical, cognitive, and social activities. Each category included 3 specific items. Demographic data and other potential confounding factors were also assessed.

Results

In the 15 month follow‐up survey, 239 participants (7.7%) reported increased depressive symptoms. Multiple logistic regression analysis indicated that engagement in light physical exercise (odds ratio = 0.74, 95%, CI = 0.56‐0.98), taking enrichment lessons (0.62, 0.46‐0.85), using a personal computer (0.68, 0.48‐0.97), participation in events at the community center (0.54, 0.40‐0.72), and attending a community meeting (0.69, 0.52‐0.92) were independently associated with lower risk of increased depressive symptoms. In a separate analysis for each gender, significant odds ratios of using a personal computer were observed in men, whereas significant odds ratios of light physical exercise, participation in events at the community center, and attending a community meeting were observed in women.

Conclusions

Light physical exercise, taking lessons, usage of a computer, and participation in community events showed protective effects against depressive symptoms. However, the significance of each behavioral factor may vary according to gender.
Natural convection in a parabolic enclosure with an internal vertical heat source filled with Cu–water nanofluid
Authors: Hussein Ahmed Kadhim , Mustafa Ahmed Waheed
Published: August 2017

The numerical investigation of the natural convection in concave and convex parabolic enclosures with a nanofluid consisting of water and copper nanoparticles is carried out by using the finite volume method. The upper and lower walls of the enclosures are adiabatic while the sidewalls are isothermal at a cold temperature. An internal heat source of constant length (ε = 0.2) and negligible thickness is placed at various vertical positions along the center of the enclosure. It was found that the increase in the location of the heat source leads to a drop in the water and nanofluid flow circulation in both types of enclosures.

For both considered Cases I and II, the average Nusselt number increases when the Rayleigh number and solid volume fraction increase. Moreover, it was concluded that Case I with δ = 0.8 is the optimum case for heat transfer enhancement for Ra = 103 and Ra = 104. Case II with δ = 0.5 is optimum for Ra = 105. Both cases are satisfied when the nanofluid is used with ϕ = 0.2.
CFD simulation on the performance of twin thermoacoustic prime mover for various resonator lengths and operating pressures
Authors: Hariharan N.M. , Arun S. , Sivashanmugam P. , Kasthurirengan S.
Published: August 2017

The main objective of the present investigation is to analyze the effect of resonator length and different working pressures on the performance of a twin thermoacoustic prime mover, which was measured in terms of frequency and amplitude of the oscillations using the computational fluid dynamics tool FLUENT 6.3. The simulation was carried out for different resonator lengths such as 0.5, 0.6, 0.8, 1.1, and 1.4 m using nitrogen as a working fluid for various operating pressures such as 1, 2, 3, 4, and 5 bar. It was observed from the results that the pressure amplitude increases with an increase in resonator length and that the output frequency decreases with an increase in resonator length for a fixed operating pressure. For a constant resonator length, the increase in operating pressure has little influence on output frequency, and the pressure amplitude also increases. The results obtained were found to be in accordance with experimental works published by Hariharan and colleagues.
Risk of Cause‐Specific Death in Individuals with Cancer—Modifying Role Diabetes, Statins and Metformin
Authors: Haukka Jari , Niskanen Leo , Auvinen Anssi
Published: August 2017

Both diabetes mellitus (DM) and cancer are common diseases and they frequently occur in the same patients. We investigated the all‐cause and cause‐specific mortality dynamics in relation to baseline DM, statin use and metformin use. The study population consisted of 39,900 incident cancer cases from Finland, 19,822 patients were free of DM at the start of follow‐up and 20,078 had DM. Mortality from all causes, and cancer, cardiovascular (CVD) and other causes was analysed using Poisson regression model with the following variables: sex, age, DM, statin and metformin usage in baseline, cancer type and stage and calendar period. Statin usage was associated with a reduced cancer‐specific mortality with incidence rate ratio (IRR) 0.72 (95% confidence interval 0.69–0.74), IRR for CVD mortality was 0.95 (0.88–1.02) and for other causes 0.64 (0.56–0.74). In a sub‐population of DM patients, IRR for metformin in all‐cause mortality was 0.74 (0.71–0.78), in cancer mortality 0.75 (0.72–0.79), in CVD mortality 0.75 (0.68–0.83) and other causes 0.68 (0.60–0.78). In conclusion, our register‐based study of survival after cancer diagnosis showed that patients with diabetes had substantially poorer outcome in all measures. An association between baseline statin usage and lower all‐cause, cancer and cardiovascular mortality was modified by cancer type. The effect of statin use was largest for breast and colorectal cancer. Metformin usage in a subpopulation of oral antidiabetic users was in general associated with lower mortality, but this association was modified by cancer type. The association was strongest for liver, colorectal and breast cancer.
Tissue distribution following 28 day repeated oral administration of aluminum‐based nanoparticles with different properties and the in vitro toxicity
Authors: Park Eun‐Jung , Lee Gwang‐Hee , Yoon Cheolho , Jeong Uiseok , Kim Younghun , Chang Jaerak , Kim Dong‐Wan
Published: August 2017

The tissue distribution and toxicity of nanoparticles (NPs) depend on their physical and chemical properties both in the manufactured condition and within the biological system. We characterized three types of commercially available aluminum‐based NPs (Al‐NPs), two rod‐type aluminum oxide NPs (Al2O3, AlONPs), with different aspect ratios (short [S]‐ and long [L]‐AlONPs), and spherical aluminum cerium oxide NPs (AlCeO3, AlCeONPs). The surface area was in order of the S‐AlONPs > L‐AlONPs > AlCeONPs. Very importantly, we found that AlCeONPs is Al2O3‐coated CeO2 NPs, but not AlCeO3 NPs, and that the Al level in AlCeONPs is approximately 20% of those in S‐ and L‐AlONPs. All three types of Al‐NPs were slightly ionized in gastric fluid and rapidly particlized in the intestinal fluid. There were no significant differences in the body weight gain following 28 days of repeated oral administration of the three different types of Al‐NPs. All Al‐NPs elevated Al level in the heart, spleen, kidney and blood at 24 hours after the final dose, accompanied by the altered tissue level of redox reaction‐related trace elements. Subsequently, in four types of cells derived from the organs which Al‐NPs are accumulated, H9C2 (heart), HEK‐293 (kidney), splenocytes and RAW264.7 (blood), S‐AlONPs showed a very low uptake level and did not exert significant cytotoxicity. Meanwhile, cytotoxicity and uptake level were the most remarkable in cells treated with AlCeONPs. In conclusion, we suggest that the physicochemical properties of NPs should be examined in detail before the release into the market to prevent unexpected adverse health effects.
Butyltin compounds alter secretion of interleukin 6 from human immune cells
Authors: Brown Shyretha , Wilburn Wendy , Martin Tyesha , Whalen Margaret
Published: August 2017

Butyltins (BTs), tributyltin (TBT) and dibutyltin (DBT) are organotin compounds that have been used in a variety of industrial applications; as a result, these compounds have been found in human blood. Interleukin (IL)‐6 is a proinflammatory mediator that is produced by T lymphocytes and monocytes. It is responsible for immune response regulation as well as tissue repair and cellular growth. Both BTs decrease the ability of human natural killer cells to destroy tumor cells and alter the secretion of proinflammatory cytokines tumor necrosis factor alpha, interferon gamma and IL‐1 beta (β) from human lymphocytes ex vivo. Here, we show that BTs alter the secretion of IL‐6 from increasingly reconstituted preparations of human immune cells. IL‐6 secretion was examined after 24 hour, 48 hour or 6 day exposures to TBT and DBT in highly enriched human natural killer cells, monocyte‐depleted peripheral blood mononuclear cells (PBMCs), PBMCs, granulocytes and a preparation combining both PBMCs and granulocytes (PBMCs + granulocytes). The results indicated that both BTs altered IL‐6 secretion from all cell preparations. Significant decreases of IL‐6 secretion were seen at the highest concentration of TBT (200 nm) and DBT (5–2.5 μm) while the lower concentrations of DBT (0.05 and 0.1 μm) caused elevation of IL‐6 secretion. The data indicate that BT‐induced alterations of IL‐6 secretion from immune cells may be a significant consequence of BT exposures that may potentially affect immune competence.
How do people become plasma and platelet donors in a VNR context?
Authors: Charbonneau Johanne , Cloutier Marie‐Soleil , Fainstein Balia
Published: August 2017

Background

The demand for therapeutic plasma‐derived products poses a challenge to blood collection agencies (BCAs). In 2014–2015, the volume of plasma sent for fractionation met 17.7% of Quebec's needs for immunoglobulins. This article aims to offer an exploration of the paths blood donors follow in order to become plasma and platelet donors (PPDs).

Study Design and Method

This analysis is based on semi‐structured interviews with 50 PPDs in Quebec, Canada. Our analysis focused on the occurrence of events and the presence of contextual elements identified through: (1) factual data on PPDs; and (2) what PPDs identified as being an influence on their donation experience. This information was synthesized using a typology of trajectories.

Results

Six typical trajectories have been distinguished, first by the presence (19/50 respondents) or absence (31/50) of blood donation as a family tradition. Of the latter 31 donors, some pointed instead to inherited family values as having a significant influence on their commitment (11/31). Donors' careers were then distinguished as having started early (34) or late (16). Sub‐types then appeared with the addition of other contextual elements, motivation profiles, and circumstances under which the conversion to apheresis donation occurred.

Conclusion

Our findings suggest the existence of diversified donor trajectories, and confirm the importance of conducting more in‐depth analyses of the sequence of events occurring along PPDs career. BCAs should develop strategies carefully tailored to different potential clienteles if they wish to convert whole blood donors to apheresis donation, and also focus on recruiting and retaining young PPDs.
Efficacy of independence sampling in replica exchange simulations of ordered and disordered proteins
Authors: Lee Kuo Hao , Chen Jianhan
Published: August 2017

Recasting temperature replica exchange (T‐RE) as a special case of Gibbs sampling has led to a simple and efficient scheme for enhanced mixing (Chodera and Shirts, J. Chem. Phys., 2011, 135, 194110). To critically examine if T‐RE with independence sampling (T‐REis) improves conformational sampling, we performed T‐RE and T‐REis simulations of ordered and disordered proteins using coarse‐grained and atomistic models. The results demonstrate that T‐REis effectively increase the replica mobility in temperatures space with minimal computational overhead, especially for folded proteins. However, enhanced mixing does not translate well into improved conformational sampling. The convergences of thermodynamic properties interested are similar, with slight improvements for T‐REis of ordered systems. The study re‐affirms the efficiency of T‐RE does not appear to be limited by temperature diffusion, but by the inherent rates of spontaneous large‐scale conformational re‐arrangements. Due to its simplicity and efficacy of enhanced mixing, T‐REis is expected to be more effective when incorporated with various Hamiltonian‐RE protocols. © 2017 Wiley Periodicals, Inc.
The influence of different skin types on GSR sampling by tape lifting for SEM analysis
Authors: Kara İlker
Published: August 2017

In this study, the change in the amounts the gunshot residues (GSR) collected by the “swab” method from shooter's right hand was analyzed using Scanning Electron Microscope‐Energy Dispersive Spectroscopy (SEM‐EDS) to test dependency on various conditions (such as skin color of the shooter, various physical properties, hair density of hands, size of the hands, sweaty or creamy (oiliness) hands). As a result of the analysis, there was no significant difference in the amount of GSR according to skin color, however, there was a change in the amount of GSR depending on the physical characteristics of the shooter. These results thought to have practical benefits for the experts performing GSR analysis using the swab technique to assess the incidence.
Fast redesign and geometry scaling of multiband antennas using inverse surrogate modeling techniques
Authors: Koziel Slawomir , Bekasiewicz Adrian
Published: August 2017

Redesign of antenna structures for various operating conditions or substrate parameters is a practically important problem in antenna engineering. At the same time, it is challenging because finding an optimum set of geometry parameters for a specified operating/material conditions requires going through an entire design optimization process. The problem is even more challenging for multiband antennas where 2 or more bands need to be independently controlled and the joint influence of some of antenna dimensions on several bands has to be taken into account. In this work, we propose a simple technique for rapid dimension scaling of multiband antennas, which uses inverse surrogate modeling techniques. The inverse surrogate model constructed using a set of reference designs optimized for several values of operating frequencies allows us to predict optimum dimensions of the antenna structure of interest corresponding to a required set of operating frequencies. The model is constructed at the level of coarse‐discretization electromagnetic simulations; therefore, it undergoes enhancement so as to be reliably used to redesign the antenna at the level of its high‐fidelity electromagnetic model. A correction procedure is further applied to accommodate the initial scaling errors. Our approach is demonstrated using a triple‐band uniplanar dipole antenna.
A method for solar radiation error correction of temperature measured in a reinforced plastic screen for climatic data collection
Authors: Yang Jie , Liu Qingquan , Dai Wei
Published: August 2017

Due to solar radiation effect, air temperature sensor inside a reinforced plastic screen may produce a measurement error that is 0.8 °C or higher. To improve air temperature observation accuracy and correct historical temperature of weather stations, a radiation error correction method is proposed. The correction method is based on a computational fluid dynamics (CFD) method and a neural network method. The CFD method is implemented to obtain the radiation error of a reinforced plastic screen under various environmental conditions. Then, a radiation error correction equation is obtained by fitting the CFD results using the neural network method. To verify the performance of the radiation error correction equation, a reinforced plastic screen and an aspirated temperature measurement platform are characterized in the same environment to conduct the intercomparison. The aspirated temperature measurement platform serves as an air temperature reference. The average radiation error given by four sunny days intercomparison experiments is 0.85 °C. The corresponding average radiation error given by the correction equation is 0.83 °C. The mean absolute error, the root mean square error and the correlation coefficient between the radiation errors given by the correction equation and the radiation errors given by the experiments with the reference platform are 0.099, 0.109 and 0.713 °C, respectively.
Metabolic dysregulation accelerates injury‐induced joint degeneration, driven by local inflammation; an in vivo rat study
Authors: de Visser Huub M. , Mastbergen Simon C. , Kozijn Anne E. , Coeleveld Katja , Pouran Behdad , van Rijen Mattie H. , Lafeber Floris P. J. G. , Weinans Harrie
Published: August 2017

Evidence is growing for the existence of an obesity‐related phenotype of osteoarthritis in which low‐grade inflammation and a disturbed metabolic profile play a role. The contribution of an obesity‐induced metabolic dysbalance to the progression of the features of osteoarthritis upon mechanically induced cartilage damage was studied in a rat in vivo model. Forty Wistar rats were randomly allocated 1:1 to a standard diet or a high‐fat diet. After 12 weeks, in 14 out of 20 rats in each group, cartilage was mechanically damaged in the right knee joint. The remaining six animals in each group served as controls. After a subsequent 12 weeks, serum was collected for metabolic state, subchondral bone changes assessed by μCT imaging, osteoarthritis severity determined by histology, and macrophage presence assessed by CD68 staining. The high‐fat diet increased statistically all relevant metabolic parameters, resulting in a dysmetabolic state and subsequent synovial inflammation, whereas cartilage degeneration was hardly influenced. The high‐fat condition in combination with mechanical cartilage damage resulted in a clear statistically significant progression of the osteoarthritic features, with increased synovitis and multiple large osteophytes. Both the synovium and osteophytes contained numerous CD68 positive cells. It is concluded that a metabolic dysbalance due to a high‐fat diet increases joint inflammation without cartilage degeneration. The dysmetabolic state clearly accelerates progression of osteoarthritis upon surgically induced cartilage damage supported by inflammatory responses as demonstrated by histology and increased CD68 expressing cells localized on the synovial membrane and osteophytes. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:881–890, 2018.
Quantitative spontaneous Raman scattering spectroscopy in artificial binary lipid membranes
Authors: Rieger S. , Grill D. , Gerke V. , Fallnich C.
Published: August 2017

The cholesterol concentration in lipid membranes is an important parameter that influences signaling processes as well as the structure of membranes. We show that the cholesterol content in giant unilamellar vesicles from binary lipid mixtures of cholesterol and 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine can be quantitatively assessed with spontaneous Raman scattering spectroscopy. An analytical model employing correlation analysis is introduced, which can be applied for the determination of the actual cholesterol content in unilamellar lipid membranes of lipid compositions that are unknown or, because of external effects, deviant from the weighed‐in values. Copyright © 2017 John Wiley & Sons, Ltd.
Tip‐enhanced Raman scattering of graphene
Authors: Beams Ryan
Published: August 2017

This article reviews the mechanism of tip‐enhanced Raman spectroscopy (TERS) and its importance for characterizing graphene. The theoretical foundation of TERS and experimental implementation are discussed. Conventionally, Raman scattering is treated as a spatially incoherent process where the total signal is proportional to the scattering volume. However, in the near‐field regime, the scattered fields can add coherently because the TERS interaction volume is on the same length scale as the phonon correlation length. These coherence effects are significant for two‐dimensional materials as will be discussed theoretically and experimentally. Therefore, TERS provides an optical method to probe phonon correlations at the nanoscale. In addition, this article will review the TERS applications for characterizing defects, edges, and nanoscale strain in graphene. Finally, the outlook and future applications are discussed. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.
Use of Ionic liquids as additives in ion exchange chromatography for the analysis of cations
Authors: Di Huawei , Zhu Xiashi
Published: August 2017

The behavior of acids (citric acid, nitric acid, oxalic acid, tartaric acid) as a mobile phase and imidazolium ionic liquids (the bromides, tetrafluoroborates and hexafluorophosphates of 1‐ethyl, 1‐butyl, and 1‐hexyl‐3‐methylimidazolium) as additives in ion exchange chromatography for cations (Na+, K+, Mg2+, Ca2+) separation were studied. The results showed that nitric acid and 1‐hexyl‐3‐methyl‐imidazolium hexafluorophosphate offered the most interesting features in the separation of cations, such as lower retention time and better resolution. The selected optimal conditions were achieved by adding 0.10 mM 1‐hexyl‐3‐methyl‐imidazolium hexafluorophosphate in 4.0 mM HNO3 mobile phase for the separation of four cations with the flow rate of 0.9 mL/min at room temperature (25°C). The linear regression equations of Na+, K+, Mg2+, Ca2+ were S = 4.4763c + 0.0209, S = 3.8903c – 0.0087, S = 6.3974c – 0.0173, and S = 7.601c – 0.0339 and the limits of detection of Na+, K+, Mg2+, Ca2+ were 0.296, 4.98, 0.0970, and 1.22 μg/L, respectively. In this work, four cations in samples were successfully detected.
Stimuli‐Responsive Dipeptide–Protein Hydrogels through Schiff Base Coassembly
Authors: Yuan Tingting , Fei Jinbo , Xu Youqian , Yang Xiaoke , Li Junbai
Published: August 2017

Different from the conventional irreversible covalent conjugations, a simple and efficient dynamic Schiff base covalent assembly is developed to construct the stable and smart dipeptide–protein hydrogels under mild conditions. Diphenylalanine–hemoglobin hydrogel is chosen to investigate the gelation formation process and mechanism. It is found that such assembled dipeptide–protein hydrogels are sensitive to pH variation, and simultaneously the proteins can be released without changing the native secondary structures from the gels. Furthermore, these adaptive hydrogels can encapsulate a series of small molecules, multicomponent proteins, and functional nanoparticles. These versatile hydrogels may find a great potential in bioapplications.
Improved Glass Transition Temperature towards Thermal Stability via Thiols Solvent Additive versus DIO in Polymer Solar Cells
Authors: Yin Jingping , Zhou Weihua , Zhang Lin , Xie Yuanpeng , Yu Zoukangning , Shao Jun , Ma Wei , Zeng Jianrong , Chen Yiwang
Published: August 2017

The halogen‐free solvent additive, 1,4‐butanedithiol (BT) has been incorporated into PTB7‐Th:PC71BM, leading to higher power conversion efficiency (PCE) value as well as substantially enhanced thermal stability, as compared with the traditional 1,8‐diiodooctane (DIO) additive. More importantly, the improved thermal stability after processing with BT contributes to a higher glass transition temperature (Tg) of PTB7‐Th, as determined by dynamic mechanical analysis. After thermal annealing at 130 °C in nitrogen atmosphere for 30 min, the PCE of the specimen processed with BT reduces from 9.3% to 7.1%, approaching to 80% of its original value. In contrast, the PCE of specimens processed with DIO seriously depresses from 8.3% to 3.8%. These findings demonstrate that smart utilization of low‐boiling‐point solvent additive is an effective and practical strategy to overcome thermal instability of organic solar cells via enhancing the Tg of donor polymer.
Comparison of different compressed sensing algorithms for low SNR 19F MRI applications—Imaging of transplanted pancreatic islets and cells labeled with perfluorocarbons
Authors: Liang Sayuan , Dresselaers Tom , Louchami Karim , Zhu Ce , Liu Yipeng , Himmelreich Uwe
Published: August 2017

Transplantation of pancreatic islets is a possible treatment option for patients suffering from Type I diabetes. In vivo imaging of transplanted islets is important for assessment of the transplantation site and islet distribution. Thanks to its high specificity, the absence of intrinsic background signal in tissue and its potential for quantification, 19F MRI is a promising technique for monitoring the fate of transplanted islets in vivo. In order to overcome the inherent low sensitivity of 19F MRI, leading to long acquisition times with low signal‐to‐noise ratio (SNR), compressed sensing (CS) techniques are a valuable option. We have validated and compared different CS algorithms for acceleration of 19F MRI acquisition in a low SNR regime using pancreatic islets labeled with perfluorocarbons both in vitro and in vivo.

Using offline simulation on both in vitro and in vivo low SNR fully sampled 19F MRI datasets of labeled islets, we have shown that CS is effective in reducing the image acquisition time by a factor of three to four without seriously affecting SNR, regardless of the particular algorithms used in this study, with the exception of CoSaMP. Using CS, signals can be detected that might have been missed by conventional 19F MRI. Among different algorithms (SPARSEMRI, OMMP, IRWL1, Two‐level and CoSAMP), the two‐level l1 method has shown the best performance if computational time is taken into account.

We have demonstrated in this study that different existing CS algorithms can be used effectively for low SNR 19F MRI. An up to fourfold gain in SNR/scan time could be used either to reduce the scan time, which is beneficial for clinical and translational applications, or to increase the number of averages, to potentially detect otherwise undetected signal when compared with conventional 19F MRI acquisitions. Potential applications in the field of cell therapy have been demonstrated.
Precision and accuracy of diffusion kurtosis estimation and the influence of b‐value selection
Authors: Chuhutin Andrey , Hansen Brian , Jespersen Sune Nørhøj
Published: August 2017

Diffusion kurtosis imaging (DKI) is an extension of diffusion tensor imaging that accounts for leading non‐Gaussian diffusion effects. In DKI studies, a wide range of different gradient strengths (b‐values) is used, which is known to affect the estimated diffusivity and kurtosis parameters. Hence there is a need to assess the accuracy and precision of the estimated parameters as a function of b‐value. This work examines the error in the estimation of mean of the kurtosis tensor (MKT) with respect to the ground truth, using simulations based on a biophysical model for both gray (GM) and white (WM) matter. Model parameters are derived from densely sampled experimental data acquired in ex vivo rat brain and in vivo human brain. Additionally, the variability of MKT is studied using the experimental data. Prevalent fitting protocols are implemented and investigated. The results show strong dependence on the maximum b‐value of both net relative error and standard deviation of error for all of the employed fitting protocols. The choice of b‐values with minimum MKT estimation error and standard deviation of error was found to depend on the protocol type and the tissue. Protocols that utilize two terms of the cumulant expansion (DKI) were found to achieve minimum error in GM at b‐values less than 1 ms/μm2, whereas maximal b‐values of about 2.5 ms/μm2 were found to be optimal in WM. Protocols including additional higher order terms of the cumulant expansion were found to provide higher accuracy for the more commonly used b‐value regime in GM, but were associated with higher error in WM. Averaged over multiple voxels, a net average error of around 15% for both WM and GM was observed for the optimal b‐value choice. These results suggest caution when using DKI generated metrics for microstructural modeling and when comparing results obtained using different fitting techniques and b‐values.
PROP Nontaster Women Lose More Weight Following a Low‐Carbohydrate Versus a Low‐Fat Diet in a Randomized Controlled Trial
Authors: Burgess Brenda , Raynor Hollie A. , Tepper Beverly J.
Published: August 2017

Objective

Taste blindness to 6‐n‐propylthiouracil (PROP) associates with increased fat preference and intake. No studies have matched a diet to a woman's PROP phenotype to improve weight loss. This study investigated (1) whether PROP nontaster (NT) women would lose more weight following a low‐carbohydrate (LC) diet than a low‐fat (LF) diet, and (2) whether PROP supertaster (ST) women would lose more weight following a LF diet than a LC diet.

Methods

One hundred seven women (BMI = 34.8 ± 0.5 kg/m2), classified as PROP NTs (n = 47) and STs (n = 60), were randomized to a LC or LF diet within a 6‐month lifestyle intervention. Assessments included 4‐day dietary recalls and biobehavioral and psychosocial questionnaires.

Results

At 6 months, NTs lost more weight following the LC than the LF diet (−8.5 ± 0.5 kg vs. −6.6 ± 0.5 kg, P = 0.008); there was no difference between STs following either diet (−8.8 ± 0.4 vs. −8.9 ± 0.5, P = 0.35). Dietary self‐reports were unrelated to weight loss, and prescription of a LC diet associated with greater self‐efficacy.

Conclusions

NT women lost more weight following the LC diet compared to the LF diet. Screening for PROP phenotype may help personalize diet therapy for NT women to optimize their short‐term weight loss.
Incorporating Refractory Period in Mechanical Stimulation Mitigates Obesity‐Induced Adipose Tissue Dysfunction in Adult Mice
Authors: Patel Vihitaben S. , Chan M. Ete , Pagnotti Gabriel M. , Frechette Danielle M. , Rubin Janet , Rubin Clinton T.
Published: August 2017

Objective

The aim of this study was to determine whether inclusion of a refractory period between bouts of low‐magnitude mechanical stimulation (LMMS) can curb obesity‐induced adipose tissue dysfunction and sequelae in adult mice.

Methods

A diet‐induced obesity model that included a diet with 45% of kilocalories from fat was employed with intention to treat. C57BL/6J mice were weight matched into four groups: low‐fat diet (LFD, n = 8), high‐fat diet (HFD, n = 8), HFD with one bout of 30‐minute LMMS (HFDv, n = 9), and HFD with two bouts of 15‐minute LMMS with a 5‐hour separation (refractory period, RHFDv, n = 9). Two weeks of diet was followed by 6 weeks of diet plus LMMS.

Results

HFD and HFDv mice continued gaining body weight and visceral adiposity throughout the experiment, which was mitigated in RHFDv mice. Compared with LFD mice, HFD and HFDv mice had increased rates of adipocyte hypertrophy, increased immune cell infiltration (B cells, T cells, and macrophages) into adipose tissue, increased adipose tissue inflammation (tumor necrosis factor alpha gene expression), and a decreased proportion of mesenchymal stem cells in adipose tissue, all of which were rescued in RHFDv mice. Glucose intolerance and insulin resistance were elevated in HFD and HFDv mice, but not in RHFDv mice, as compared with LFD mice.

Conclusions

Incorporating a 5‐hour refractory period between bouts of LMMS attenuates obesity‐induced adipose tissue dysfunction and improves glucose metabolism.
Geometry modeling and permeability prediction for textile preforms with nesting in laminates
Authors: Yang Bo , Wang Shilong , Tang Qian
Published: August 2017

In the multilayer textile preform which is usually used in the resin transfer molding (RTM) process, the penetration phenomenon existing between two neighboring layers is referred to as nesting, which has important influence on the permeability of the preforms. Predicting the permeability of the textile preforms with nesting accurately is the foundation of mold‐filling simulation and process optimization for RTM. In this article, based on the analyses of the penetration and local deformation behaviors between two neighboring layers, an assumption on constant area of yarn cross‐section is established, and a long axis compensation method is proposed to build the geometry model of the multilayer textile preform with nesting in laminates. The governing equations of the resin flow in textile preform are built, and a high resolution total variation diminishing difference scheme is constructed based on Adams–Bashforth scheme and Chorin projection method to numerically solve the above equations and predict the permeability of the preform. According to the comparison between simulation predictions and experimental measurements, the validities of the above geometry modeling method and permeability prediction algorithm are proved. POLYM. COMPOS., 39:4408–4415, 2018. © 2017 Society of Plastics Engineers
Improving CO2 separation performance by incorporating MWCNTs@mSiO2 core@shell filler in mixed matrix membranes
Authors: Hou Jinpeng , Li Xueqin , Guo Ruili , Qin Yun , Zhang Jianshu
Published: August 2017

To improve CO2 separation performance in mixed matrix membranes (MMMs), a novel mesoporous silica‐coated on the outer surface of multi‐walled carbon nanotube (MWCNTs@mSiO2) core@shell filler was synthesized and dispersed into Pebax MH 1657 (TPE) matrix. The introduced mSiO2 layer on the outer surface of MWCNTs have a favorable effect on the dispersion and compatibility of MWCNTs@mSiO2 core@shell filler in TPE matrix. Most importantly, the pore channels of mesoporous silica and MWCNTs constructed the feasible gas transport pathways for CO2 permeation in MMMs. The MMMs presented the best CO2 separation performance when the content of MWCNTs@mSiO2 in TPE matrix was 10 wt%. The CO2 permeability and CO2/CH4 selectivity of TPE‐MWCNTs@mSiO2‐10 membrane were 379 Barrer and 39 for CO2/CH4 mixed‐gas, respectively. The CO2 permeability and CO2/N2 selectivity of TPE‐MWCNTs@mSiO2‐10 membrane were 364 Barrer and 58 for CO2/N2 mixed‐gas, respectively. POLYM. COMPOS., 39:4486–4495, 2018. © 2017 Society of Plastics Engineers
Controlling confounding by frailty when estimating influenza vaccine effectiveness using predictors of dependency in activities of daily living
Authors: Zhang Henry T. , McGrath Leah J. , Wyss Richard , Ellis Alan R. , Stürmer Til
Published: August 2017

Purpose

To improve control of confounding by frailty when estimating the effect of influenza vaccination on all‐cause mortality by controlling for a published set of claims‐based predictors of dependency in activities of daily living (ADL).

Methods

Using Medicare claims data, a cohort of beneficiaries >65 years of age was followed from September 1, 2007, to April 12, 2008, with covariates assessed in the 6 months before follow‐up. We estimated Cox proportional hazards models of all‐cause mortality, with influenza vaccination as a time‐varying exposure. We controlled for common demographics, comorbidities, and health care utilization variables and then added 20 ADL dependency predictors. To gauge residual confounding, we estimated pre‐influenza season hazard ratios (HRs) between September 1, 2007 and January 5, 2008, which should be 1.0 in the absence of bias.

Results

A cohort of 2 235 140 beneficiaries was created, with a median follow‐up of 224 days. Overall, 52% were vaccinated and 4% died during follow‐up. During the pre‐influenza season period, controlling for demographics, comorbidities, and health care use resulted in a HR of 0.66 (0.64, 0.67). Adding the ADL dependency predictors moved the HR to 0.68 (0.67, 0.70). Controlling for demographics and ADL dependency predictors alone resulted in a HR of 0.68 (0.66, 0.70).

Conclusions

Results were consistent with those in the literature, with significant uncontrolled confounding after adjustment for demographics, comorbidities, and health care use. Adding ADL dependency predictors moved HRs slightly closer to the null. Of the comorbidities, health care use variables, and ADL dependency predictors, the last set reduced confounding most. However, substantial uncontrolled confounding remained.
Highly thermal conductive benzoxazine‐epoxy interpenetrating polymer networks containing liquid crystalline structures
Authors: Liu Ying , Chen Jiming , Zhang Yaoheng , Gao Sheng , Lu Zaijun , Xue Qingbin
Published: August 2017

A diamine‐based benzoxazine monomer (Bz) and a liquid crystalline epoxy monomer (LCE) are synthesized, respectively. Subsequently, a benzoxazine‐epoxy interpenetrating polymer network (PBEI) containing liquid crystalline structures is obtained by sequential curing of the LCE and the Bz in the presence of imidazole. The results show that the preferential curing of LCE plays a key role in the formation mechanism of liquid crystalline phase. Due to the introduction of liquid crystalline structures, the thermal conductivity of PBEI increases with increasing content of LCE. When the content of LCE is 80 wt %, the thermal conductivity reaches 0.32 W m−1 K−1. Additionally, the heat‐resistance of PBEI is superior to liquid crystalline epoxy resin. Among them, PBEI55 containing equal weight of Bz and LCE has better comprehensive performance. Its thermal conductivity, glass transition temperature, and the 5 % weight loss temperature are 0.28 W m−1 K−1, 160 °C, and 339 °C, respectively. By introducing boron nitride (BN) fillers into PBEI55, a composite of PBEI/BN with the highest thermal conductivity of 3.00 W m−1 K−1 is obtained. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1813–1821
Hot Spot Formation in Mock Materials in Impact Sensitivity Testing by Drop Hammer
Authors: Reynolds John G. , Hsu Peter C. , Hust Gary A. , Strout Stephen A. , Springer H. Keo
Published: August 2017

Powder and granulated sugars were exposed to the drop hammer impact test configured with 120‐ and 180‐grit Si/C sandpapers. The sugars were selected as mock materials for HMX (Octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine). The drop heights ranged from 24.2 to 40.7 cm. Samples were examined by visible microscopy before and after testing and the appearance of yellow and brown discolorations in the spent samples were assigned as hot spots. These discolorations were divided into two types; those collocated with grit particles and those that were not. Hot spots are found in the spent samples in almost every test condition. Powder sugar appears to be more active in producing hot spots than the granulated sugar based on comparisons at identical conditions. Drop height, within this specific range, has little effect on the formation of hot spots, except for 40.7 cm high‐end limit, which causes a dramatic increase in spot formation. The predominant hot spot type formed is collocated with grit particles, suggesting association of hot spot formation due to grit, something that has been discussed in previous treaties. Foreign objects were also observed, some imbedded and some not imbedded. Discoloration was not observed around these sites, suggesting these types of foreign materials are not responsible for hot spot formation, at least under these conditions. Grit associated with a visible tail was observed in some instances, suggesting that grit can be quite mobile through the sample when the pressure is applied by the drop weight (through the striker).
Experimental Observation of Negative Capacitance Switching Behavior in One‐Transistor Ferroelectric Versatile Memory
Authors: Cheng Chun‐Hu , Chiu Yu‐Chien , Liou Guan‐Lin
Published: August 2017

In this work, we investigated the negative capacitance behavior of novel ferroelectric versatile memory with low‐voltage‐driven and fast ferroelectric switching. The combined storage mechanism strengthened the stability of ferroelectric polarization by interface aligned dipoles. The simulation results of first principle calculation indicated that the monoclinic‐like orthorhombic phase of ferroelectric hafnium oxide facilitated the occurrence of S‐shaped negative capacitance behavior. Furthermore, the control of phase transition may affect ferroelectric property and negative capacitance effect during program and erase states.
Evaluating Efficacy and Safety of Combination Medication of Atorvastatin and a Herbal Formula Containing Salvia miltiorrhiza and Pueraria lobata on Hyperlipidemia
Authors: Cheung David Wing‐Shing , Koon Chi‐Man , Wong Pui‐Han , Yau Ka‐Chun , Wat Elaine , Hung Angela Sze‐Man , Wang Yan‐Ping , Lau Kit‐Man , Ko Chun‐Hay , Chan Judy Yuet‐Wa , Waye Mary Miu‐Yee , Fung Kwok‐Pui
Published: August 2017

Despite being a potent hypolipidemic drug, atorvastatin (AS) possesses certain adverse effects. Using AS and an herbal formula (Danshen and Gegen, DG) in combination may achieve potentiated hypolipidemic effects and also reduce its adverse effects. Hence, this study aimed to investigate the efficacy and safety of an AS and DG combination on high‐fat diet‐induced hyperlipidemia. Treatment outcomes were assessed by measuring parameters including body weight, adipose tissue, liver, total cholesterol, triglyceride, and low‐density and high‐density lipoprotein cholesterol. Measurements of adverse effects were achieved by determining aspartate aminotransferase (AST), alanine transaminase (ALT), and creatine kinase (CK). Danshen and Gegen, as well as AS alone, reduced body weight, adipose tissue, liver weight, liver fat vacuoles, total liver lipids, total cholesterol, triglyceride, low‐density lipoprotein cholesterol, and high‐density lipoprotein cholesterol in high‐fat diet‐fed mice but increased AST, ALT, and CK. A combination of AS and DG was able to enhance reduced effects on the aforementioned parameters in relation to hyperlipidemia over AS or DG alone. It also reduced the elevation of AST, ALT, and CK induced than by AS or DG alone. Results demonstrated that an AS and DG combination resulted in stronger hypolipidemic effects than with AS or DG alone. Additionally, DG might attenuate adverse effects of AS on the liver and skeletal muscle. Copyright © 2017 John Wiley & Sons, Ltd.
Immunomodulatory Activity of the Glycoprotein Isolated from the Chinese Yam (Dioscorea opposita Thunb)
Authors: Niu Xiaofeng , He Zehong , Li Weifeng , Wang Xiumei , Zhi Wenbing , Liu Fang , Qi Lin
Published: August 2017

The yam (Dioscorea opposita Thunb) is a well‐known edible food and widely used as the traditional Chinese medicine. The present investigation was designed to evaluate the immunomodulatory activity of glycoprotein (DOT) from yam and explore its possible molecular mechanisms. Results showed that the DOT could improve the cell immunity, humoral immunity and phagocytic system function of the normal mice. The DOT could also increase the production of TNF‐α, interleukin‐6 and nitric oxide and enhance the pinocytosis function of macrophages. Furthermore, the DOT increased phosphor‐p38, JNK, ERK1/2 and nuclear factor kappa B (NF‐κB) p65 protein expression in peritoneal macrophages. Taken together, our data suggest that DOT could be used as a potential immunostimulant and exert its immunomodulatory activity via mitogen‐activated protein kinases and NF‐κB signal pathways. Copyright © 2017 John Wiley & Sons, Ltd.