bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel polyhydrazides and polyoxadiazoles based on 1,3,4‐thiadiazole moiety in the main chain with high thermal stability, good solubility, and notable antimicrobial activity
Authors: Aly Kamal I. , Younis Osama , Al‐Muaikel Nayef S. , Atalla Ahmed A. , El‐Adasy Abu‐Bakr A. A. M. , Abdellah Ahmed R. 
Published: March 2019

ABSTRACTPolyoxadiazoles (PODs) and polyhydrazides (PHs) have wide potential applications; however, PODs are normally insoluble in organic solvents, do not melt, and do not express glass‐transition temperature (Tg), and also PHs do not have high‐temperature resistance. In this work, novel PHs based on 1,3,4‐thiadiazole in the polymer main chain were synthesized by low‐temperature polycondensation. New PODs were then obtained by cyclodehydration of the PHs. The thermal behavior, surface morphology, and crystalline structure were studied using differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, and X‐ray diffraction. In addition, the viscosity, solubility, UV–visible absorption, and antimicrobial activity were examined. The new polymers showed melting, Tg, high thermal stability, good solubility in polar aprotic solvents, and significant antimicrobial activities. The enhanced solubility may be attributed to the ability of thiadiazole moiety to form hydrogen bonding with the solvent molecules. Also, it can be concluded that introducing 1,3,4‐thiadiazole and other bulky moieties like the oxadiazole ring into the polymer main chain encouraged more free volumes and weakened the chains packing; hence, the solubility was enhanced and Tg decreased without affecting the thermal stability. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47770.
Multivariate asset‐pricing model based on subordinated stable processes
Authors: Panov Vladimir , Samarin Evgenii 
Published: March 2019

AbstractIn this paper, we consider a multidimensional time‐changed stochastic process in the context of asset‐pricing modeling. The proposed model is constructed from stable processes, and its construction is based on two popular concepts: multivariate subordination and Lévy copulas. From a theoretical point of view, our main result is Theorem 1, which yields a simulation method from the considered class of processes. Our empirical study shows that the model represents the correlation between asset returns quite well. Moreover, we provide some evidence that this model is more appropriate for describing stock prices than classical time‐changed Brownian motion, at least if the cumulative amount of transactions is used for a stochastic time change.
Predictors of hepatocellular carcinoma recurrence associated with the use of direct‐acting antiviral agent therapy for hepatitis C virus after curative treatment: A prospective multicenter cohort study
Authors: Nakano Masahito , Koga Hironori , Ide Tatsuya , Kuromatsu Ryoko , Hashimoto Satoru , Yatsuhashi Hiroshi , Seike Masataka , Higuchi Nobito , Nakamuta Makoto , Shakado Satoshi , Sakisaka Shotaro , Miuma Satoshi , Nakao Kazuhiko , Yoshimaru Yoko , Sasaki Yutaka , Oeda Satoshi , Eguchi Yuichiro , Honma Yuichi , Harada Masaru , Nagata Kenji , Mawatari Seiichi , Ido Akio , Maeshiro Tatsuji , Matsumoto Shuichi , Takami Yuko , Sohda Tetsuo , Torimura Takuji 
Published: March 2019

AbstractBackgroundPrevious studies have suggested an association between the use of direct‐acting antiviral agents (DAAs) for treating hepatitis C virus (HCV) infection and the resulting decrease in the incidence of hepatocellular carcinoma (HCC); however, it is unclear whether DAAs prevent the recurrence of HCC after curative treatment for HCC. This study aimed to prospectively investigate HCC recurrence and its predictors after curative treatment for HCC.MethodsA total of 3012 patients with chronic HCV infection, with or without cirrhosis, who were treated with DAAs were enrolled between January 1, 2015 and January 31, 2017 as per the institutional review board approved study protocol at 15 institutions, including 10 university hospitals and five high‐volume centers in the Kyusyu area of Japan. Of the 3012 patients, 459 patients who had HCC but were cured with surgery or ablation therapy (curative treatment) before the use of DAAs were included in the analysis.ResultsDuring a mean follow‐up period of 29.4 months, 217 (47.2%) patients developed HCC recurrence. The median time to recurrence was 34.0 months, and the 1‐, 2‐, and 3‐year cumulative HCC recurrence rates were 27.1%, 43.4%, and 50.8%, respectively. The risk factors for HCC recurrence were the α‐fetoprotein (AFP) level before DAA therapy (P = 0.0047) and the number of curative treatments for HCC before DAA therapy (P < 0.0001).ConclusionsA high AFP level and multiple occurrences of HCC before DAA therapy are associated with a high risk for HCC recurrence after curative treatment. Follow‐up after DAA therapy should include special attention to the abovementioned risk factors.
From Boron Organic Polymers to in situ Ultrafine Nano Pd and Pt: Green Synthesis and Application for High Efficiency Hydrogen Evolution
Authors: Zhao Xue , Fu Yunfan , Yao Chen , Xu Shuran , Shen Yu , Ding Qiong , Liu Wenjing , Zhang Haibo , Zhou Xiaohai 
Published: March 2019

AbstractUsing in situ reduction strategy by combining organic frameworks and ultrafine Pd and Pt nanoparticles (Pd−NPs and Pt−NPs) to synthesize composites with tunable morphology and high dispersion has attracted extensive attentions in fabrication of composite nanomaterials. Herein, on the new kind of substrate, BOPs@Pd and BOPs@Pt nano materials have been successfully fabricated via in situ reduction of Na2PdCl4 and H2PtCl6 triggered by reducibility of organic boron polymers (BOPs). The final products are obtained by loading Pd−NPs and Pt−NPs with ultra‐small size and high dispersion without any tedious chemical modification or additional additives. These materials show high catalytic activity and recyclability in the hydrolysis dehydrogenation of ammonia borane (AB).
Polysulfide Trapping in Carbon Nanofiber Cloth/S Cathode with a Bifunctional Separator for High‐Performance Li–S Batteries
Authors: Ren Wenchen , Ma Wei , Jin Xin , Zhang Shufen , Tang Bingtao 
Published: March 2019

AbstractThe development of carbon nanofiber (CNF) cloth‐based cathodes is essential for the fabrication of high energy density and flexible Li–S batteries. Surface modification is generally used to improve the electrochemical performance of CNF cloth/S cathodes. However, this strategy creates some problems such as structure collapse, complex fabrication steps, and poor consistency. Herein, a β‐MnO2 nanowire/graphene‐modified separator is used to improve the performance of CNF cloth/S cathodes without changing their structure. β‐MnO2 can facilitate chemical bonding with polysulfides, whereas graphene can decrease the inner resistance and trap polysulfide by physical shielding. The cathode with the bifunctional separator displayed a high discharge capacity of 529.9 mAh g−1 with a low capacity decay of 0.051 % per cycle after 500 cycles at 1 C, which is 3 times higher compared with a bare separator. Even with a high sulfur loading of 9.0 mg cm−2, a high areal capacity of 3.8 mAh cm−2 was delivered over 100 cycles.
Improving energy efficiency in information‐centric mobile ad‐hoc networks using places of interest while respecting privacy
Authors: Sepahkar Mehdi , Khayyambashi Mohammad Reza 
Published: March 2019

SummaryThe fact that network users mostly look for content regardless of its location has led to the creation of information‐centric networks with NDN (named data networking project) as the most famous instance. NDN can be implemented in any type of network including MANET (mobile ad‐hoc network) which can be easily created among a collection of smartphones. The first step for content retrieval in NDN is propagating interest packets which has a dramatic effect on energy consumption because of wireless communications. Methods have been devised for limiting the amount of packet propagation. But they are not appropriate for smartphones either because they require multiple WiFi interfaces which is not available in usual smartphones or because they require the exact position of nodes which conflicts privacy. In our proposed approach, a single WiFi interface is used, and mobile nodes will share only an imprecise version of their current and their predicted next location, which complies much better with privacy. Using this information, the amount of interest and data packets will decrease of more than 15%. When location information is spread through the network, this reduction will be almost doubled.
Prevalence of diabetes in liver cirrhosis: A systematic review and meta‐analysis
Authors: Lee Wai Gin , Wells Cameron I. , McCall John L. , Murphy Rinki , Plank Lindsay D. 
Published: March 2019

AbstractAn association between diabetes mellitus (DM) and liver cirrhosis is well‐known, but estimates of the prevalence of DM in patients with liver cirrhosis vary widely. A systematic review was undertaken to determine the prevalence of DM in adult patients with liver cirrhosis. The Medline, EMBASE, and Cochrane Library databases were searched for peer‐reviewed studies published in English (1979‐2017) that investigated the prevalence of diabetes in adult patients with cirrhosis. Pooled estimates of prevalence of DM were determined for all eligible patients and according to aetiology and severity of liver disease. Fifty‐eight studies satisfied criteria for inclusion, with 9705 patients included in the pooled prevalence analysis. The overall prevalence of DM was 31%. The prevalence of DM was highest in patients with nonalcoholic fatty liver disease (56%), cryptogenic (51%), hepatitis C (32%), or alcoholic (27%) cirrhosis. For assessing prevalence of DM as a function of severity of liver disease, evaluable data were available only for hepatitis C and hepatitis B cirrhosis. DM may be more prevalent in cirrhosis than previously thought. This has implications for prognosis and treatment in these patients.
A pilot wastewater‐based epidemiology assessment of anabolic steroid use in Queensland, Australia
Authors: Shimko Katja M. , O'Brien Jake W. , Barron Leon , Kayalar Hasan , Mueller Jochen F. , Tscharke Ben J. , Choi Phil M. , Jiang Hui , Eaglesham Geoff , Thomas Kevin V. 
Published: March 2019

AbstractAnabolic‐androgenic steroids are synthetic compounds prohibited due to their performance‐enhancing characteristics. The use of these substances is known to cause health‐related issues, which highlights the importance of being able to evaluate the scale of consumption by the general population. However, most available research on the analysis of anabolic steroids is focused on animals and athletes in connection with doping. The potential of wastewater‐based epidemiology as an intelligence tool for the assessment of community level use of anabolic steroids is presented herein. A liquid chromatography tandem mass spectrometry method was developed for the analysis of 10 anabolic‐androgenic steroids and 14 endogenous hormones in influent wastewater. The validated method was applied to sixteen 24‐hour composite wastewater influent samples that were collected over a period of five years from two wastewater treatment plants in Queensland, Australia. Nine investigated compounds were found to be present at concentrations between 14 and 611 ng L−1 which translated into 3–104 mg excreted per 1000 individuals per day. It was concluded that the developed analytical method is suitable for the analysis of AAS in wastewater matrix. Additionally, both the inclusion of metabolites and further investigation into deconjugation by enzymatic hydrolysis would aid in understanding and evaluating community anabolic steroid use. For the first time, this study presents the application of wastewater‐based epidemiology on anabolic‐androgenic steroids in Australia.
Does body size predict the buzz‐pollination frequencies used by bees?
Authors: De Luca Paul A. , Buchmann Stephen , Galen Candace , Mason Andrew C. , Vallejo‐Marín Mario 
Published: March 2019

AbstractBody size is an important trait linking pollinators and plants. Morphological matching between pollinators and plants is thought to reinforce pollinator fidelity, as the correct fit ensures that both parties benefit from the interaction. We investigated the influence of body size in a specialized pollination system (buzz‐pollination) where bees vibrate flowers to release pollen concealed within poricidal stamens. Specifically, we explored how body size influences the frequency of buzz‐pollination vibrations. Body size is expected to affect frequency as a result of the physical constraints it places on the indirect flight muscles that control the production of floral vibrations. Larger insects beat their wings less rapidly than smaller‐bodied insects when flying, but whether similar scaling relationships exist with floral vibrations has not been widely explored. This is important because the amount of pollen ejected is determined by the frequency of the vibration and the displacement of a bee's thorax. We conducted a field study in three ecogeographic regions (alpine, desert, grassland) and recorded flight and floral vibrations from freely foraging bees from 27 species across four families. We found that floral vibration frequencies were significantly higher than flight frequencies, but never exceeded 400 Hz. Also, only flight frequencies were negatively correlated with body size. As a bee's size increased, its buzz ratio (floral frequency/flight frequency) increased such that only the largest bees were capable of generating floral vibration frequencies that exceeded double that of their flight vibrations. These results indicate size affects the capacity of bees to raise floral vibration frequencies substantially above flight frequencies. This may put smaller bees at a competitive disadvantage because even at the maximum floral vibration frequency of 400 Hz, their inability to achieve comparable thoracic displacements as larger bees would result in generating vibrations with lower amplitudes, and thus less total pollen ejected for the same foraging effort.
Bioaccumulation of Selected Halogenated Organic Flame Retardants in Lake Ontario
Authors: Kurt-Karakus Perihan B. , Muir Derek C.G. , de Jourdan Benjamin , Teixeira Camilla , Epp Martindale Jessica , Embers Heather , Wang Xiaowa , Keir Mike , Backus Sean 
Published: March 2019

Abstract
The trophic magnification of polybrominated diphenyl ethers (PBDEs) and selected nonlegacy halogenated organic compounds (HOCs) was determined in the food web of Lake Ontario (ON, Canada). In all, 28 Br3-Br8-PBDEs and 24 HOCs (10 of which had not been targeted previously) were analyzed. Average concentrations of Σ28PBDEs in fish ranged between 79.7 ± 54.2 ng/g lipid weight in alewife (Alosa pseudoharengus) and 815 ± 695 ng/g lipid weight in lake trout (Salvelinus namaycush). For invertebrates, concentrations were between 13.4 ng/g lipid weight (net plankton; &gt;110 μm) and 41.9 ng/g lipid weight in Diaporeia (Diaporeia hoyi). Detection frequency (DF) for HOCs was highest for anti-Dechlorane Plus (anti-DDC-CO), 1,3-diiodobenzene (1,3-DiiB), tribromo-methoxy-methylbenzene (ME-TBP), allyl 2,4,6-tribromophenyl ether (TBP-AE), pentabromocyclododecene (PBCYD), α+β-tetrabromocylcooctane (TBCO), 2-bromoallyl 2,4,6-tribromophenyl ether (BATE), and pentabromotoluene (PBT; DF for all = 100% in lake trout). Tetrabromoxylene (TBX), dibromopropyl 2,4,6-tribromophenyl ether (TBP-DBPE), and syn-DDC-CO were also frequently detected in trout (DF = 70–78%), whereas 2,3,4,5,6-pentabromoethyl benzene (PBEB) was detected only in plankton. Several HOCs were reported in aquatic biota in the Great Lakes (USA/Canada) for the first time in the present study, including PBCYD, 1,3DiiB, BATE, TBP-DBPE, PBT, α + β-TBCO, and ME-TBP. The Br4-6-BDEs (−47, −85, −99, −100, −153, and −154) all had prey-weighted biomagnification factors (BMFPW) values &gt;6, whereas BMFPW values for Br7-8-BDEs were &lt;1. The highest BMFPW values of non-PBDEs were for TBP-DBPE (10.6 ± 1.34) and ME-TBP (4.88 ± 0.60), whereas TBP-AE had a BMFPW value of &lt;1. Significant (p≤ 0.05) trophic magnification factors (TMFs), both positive and negative, were found for Br4-8-BDEs (BDE 196 = 0.4; BDE 154 = 9.5) and for bis(2,4,6-tribromophenoxy)ethane (BTBPE; 0.53), PBCYD (1.8), 1,3-DiiB (0.33), and pentabromobenzene (PBB; 0.25). Food chain length was found to have a significant influence on the TMF values. Environ Toxicol Chem 2019;38:1198–1210. © 2019 SETAC
Abstract
Effects of Sublethal Chlorpyrifos Exposure on Postlarval American Lobster (Homarus americanus)
Authors: Taylor Laura J. , Mann Nicole S. , Daoud Dounia , Clark K. Fraser , van den Heuvel Michael R. , Greenwood Spencer J. 
Published: March 2019

Abstract
The organophosphate pesticide chlorpyrifos has been introduced to the marine environment via adsorption to agricultural soil runoff or as spray drift. Chlorpyrifos affects the survival of some larval decapod crustaceans, but no data exist on the impacts to the American lobster, Homarus americanus. The purpose of the present study was to assess the levels at which chlorpyrifos affects the survival of postlarval H. americanus. Using acute saltwater exposures, the 24- and 48-h median lethal concentrations were established for stage IV H. americanus (1.56 and 1.33 µg/L, respectively). Movement, acetylcholinesterase activity, intermoult period, specific growth rate, and moult increment were measured during exposure to sublethal concentrations. Movement patterns were assessed to establish a 48-h median inhibition concentration for cessation of normal movement (0.66 µg/L). Acetylcholinesterase activity was found to be inhibited immediately post-exposure to 0.50, 0.57, and 0.82 µg/L chlorpyrifos but could be recovered within a period (9–15 d) in clean seawater. Sublethal growth effects of increased intermoult period, decreased specific growth rate, and decreased moult increment were observed during exposure to an environmentally relevant concentration (0.82 µg/L). The present study suggests that H. americanus stage IV larvae were marginally less sensitive to chlorpyrifos compared with other decapods and that acute lethality of H. americanus postlarvae is not likely to occur with chlorpyrifos concentrations previously reported from aquatic environments. Environ Toxicol Chem 2019;38:1294–1301. © 2019 SETAC
Local experts finding using user comments in location‐based social networks
Authors: Cao Jiuxin , Yang Yuntao , Cao Biwei , Xue Lingyun , Li Shancang , Iqbal Muddesar , Mumtaz Shahid 
Published: March 2019

AbstractThe opinions of local experts in the location‐based social network are of great significance to the collection and dissemination of local information. In this paper, we investigated in‐depth how the user comments can be used to identify the local expert over social networks. We first illustrate the existences of potential local experts in a social network using a scored model by considering the personal profiles, comments, friend relationship, and location preferences. Then, a multidimensional model is proposed to evaluate the local expert candidates and a local expert discovery algorithm is proposed to identify local experts. Meanwhile, a scoring algorithm is proposed to train the weights in the model. Finally, an expert recommendation list can be given based on the score ranks of the candidates. Experimental results demonstrate the effectiveness of proposed model and algorithms.
Performance of maximum ratio combining of fluctuating two‐ray (FTR) mmWave channels for 5G and beyond communications
Authors: Olyaee Maryam , Eslami Mohsen , Haghighat Javad 
Published: March 2019

AbstractRecently, a millimeter‐wave band channel model for fifth generation and beyond communications, called fluctuating two‐ray (FTR) model, has been introduced, which accurately tracks the behavior of wireless communication links in that band. In this paper, the performance of maximum ratio combining (MRC) of signals received through independent FTR channels is evaluated. Closed‐form expressions for the probability distribution of the signal‐to‐noise ratio at the output of the MRC combiner, outage probability of the system, and a tight upper bound for average bit error probability are derived. From the results obtained, it is shown that MRC for FTR channels achieves the same diversity order as MRC for Rayleigh fading, and equal to the number of diversity branches. Additionally, the effects of the FTR fading model parameters on the system performance have been investigated via numerical results obtained from analytical derivations. Comparison between analytical and simulation results show that they are in excellent agreement. To the best of our knowledge, this is the first work to analyze the performance of MRC for FTR channels.
Retracted: Design and implementation of music teaching assistant platform based on Internet of Things
Authors: Li Wajia 
Published: March 2019

AbstractWith the development of society, Internet of Things (IoT) technology has attracted more and more attention. This paper uses IoT technology to enhance the music teaching assistant platform. Firstly, through analyzing users' requirements for music teaching assistant platform, based on IoT technology, the assistant platform is analyzed, and the wireless information transmission system is established. Secondly, aiming at the consumption of router nodes, the consumption model of nodes is established. By analyzing the energy consumption and service life of router nodes, it is concluded that traditional IoT has great disadvantages. Then, an improved repair strategy of IoT is proposed according to immune algorithm. By comparing three kinds of wireless sensor networks, the improved repair strategy of IoT is better when the number of router nodes is more than 400. When it comes to saving energy, there are great advantages in quantity consumption. Finally, by simulating and analyzing the fault repair of router nodes, it is concluded that the number of effective router nodes in traditional IoT decreases the fastest with the number of simulated runs, followed by energy‐gathering IoT, and the lifetime of effective router nodes in IoT is the longest with the energy‐gathering improved by immune algorithm. This research mainly focuses on the energy consumption of router nodes in the perception layer of IoT, as well as the network immunity and repair mechanism of the system. It improves and designs the traditional music teaching assistant platform, which has certain practical significance.