bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural, topographical, and mechanical characteristics of purified polyhydroxyoctanoate polymer
Authors: Sofińska Kamila , Barbasz Jakub , Witko Tomasz , Dryzek Jerzy , Haraźna Katarzyna , Witko Małgorzata , Kryściak‐Czerwenka Joanna , Guzik Maciej
Published: October 2018

Insight into the topographic and mechanical properties of biomaterials allows for efficient selection of a material for a specific application. Here, atomic force microscopy (AFM) and force spectroscopy were exploited to reveal the topographic and mechanical characteristics of charcoal‐purified, solvent‐cast polyhydroxyoctanoate (PHO) film. The root mean square surface roughness of a PHO surface derived from ethyl acetate, acetone, or chloroform solution was 13.2, 11.5, or 30.9 nm, respectively, for 100 μm2 AFM images. The distribution of the local Young's modulus had a maximum of 25.4, 14.1, and 12.6 MPa for PHO films obtained from ethyl acetate, acetone, and chloroform solution, respectively. The positron annihilation spectroscopy measurements allowed us to determine the free volume in the polymer film structure (9.38%). Moreover, a number of additional techniques (X‐ray diffraction, thermogravimetric analysis, differential scanning calorimetry, gel permeation chromatography, NMR, infrared spectroscopy, and polarized light microscopy) were used to reveal PHO features. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47192.
Flame retardancy mechanisms of melamine cyanurate in combination with aluminum diethylphosphinate in epoxy resin
Authors: Chen Wenhua , Liu Pengju , Cheng Yanbo , Liu Yuan , Wang Qi , Duan Wenfeng
Published: October 2018

A novel flame‐retardant (FR) epoxy (EP) composite based on melamine cyanurate (MCA) and aluminum diethylphosphinate (AlPi) was successfully prepared and its flame retardancy was systematically investigated. Firstly, the facile surface modification was adopted to effectively solve the aggregation of FRs in EP matrix during the curing process. The influence of modified MCA/AlPi on the fire behavior and thermal degradation of EP were studied by using limiting oxygen index (LOI), vertical burning (UL94) tests, thermogravimetric analysis and pyrolysis‐gas chromatography/mass spectrometry (Py‐GC/MS). The experimental results showed that EP/MCA/AlPi composite achieved UL‐94V0 rating and LOI value of 33.0% at the optimum mass fraction of MCA/AlPi of 2/1. The chemical composition and structure of residue were characterized by X‐ray photoelectron spectroscopy, Fourier transform infrared spectrometry and scanning electron microscopy. MCA mainly acted in gaseous phase during the initial combustion stage, and therefore to provide enough time for the formation of carbon layer in condenses phase. As a result, the synergistic effect of MCA and AlPi can effectively promote the formation of the char layer and the FR efficiency. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47223.
Dampening of CD8+ T Cell Response by B Cell Depletion Therapy in Antineutrophil Cytoplasmic Antibody–Associated Vasculitis
Authors: Néel Antoine , Bucchia Marie , Néel Mélanie , Tilly Gaelle , Caristan Aurélie , Yap Michele , Rimbert Marie , Bruneau Sarah , Cadoux Marion , Agard Christian , Hourmant Maryvonne , Godmer Pascal , Brouard Sophie , Bressollette Céline , Hamidou Mohamed , Josien Regis , Fakhouri Fadi , Degauque Nicolas
Published: October 2018

Objective

To compare the effects of rituximab (RTX) and conventional immunosuppressants (CIs) on CD4+ T cells, Treg cells, and CD8+ T cells in antineutrophil cytoplasmic antibody–associated vasculitis (AAV).

Methods

A thorough immunophenotype analysis of CD4+, Treg, and CD8+ cells from 51 patients with AAV was performed. The production of cytokines and chemokines by CD8+ T cells stimulated in vitro was assessed using a multiplex immunoassay. The impact of AAV B cells on CD8+ T cell response was assessed using autologous and heterologous cocultures.

Results

CD4+ and Treg cell subsets were comparable among RTX‐treated and CI‐treated patients. In contrast, within the CD8+ T cell compartment, RTX, but not CIS, reduced CD45RA+CCR7– (TEMRA) cell frequency (from a median of 39% before RTX treatment to 10% after RTX treatment [P < 0.01]) and efficiently dampened cytokine/chemokine production (e.g., the median macrophage inflammatory protein 1α level was 815 pg/ml in patients treated with RTX versus 985 pg/ml in patients treated with CIs versus 970 pg/ml in those with active untreated AAV [P < 0.01]). CD8+ T cell subsets cocultured with autologous B cells produced more proinflammatory cytokines in AAV patients than in controls (e.g., for tumor necrosis factor–producing effector memory CD8+ T cells: 14% in AAV patients versus 9.2% in controls [P < 0.05]). In vitro disruption of AAV B cell–CD8+ T cell cross‐talk reduced CD8+ T cell cytokine production, mirroring the reduced CD8+ response observed ex vivo after RTX treatment.

Conclusion

The disruption of a pathogenic B cell/CD8+ T cell axis may contribute to the efficacy of RTX in AAV. Further studies are needed to determine the value of CD8+ T cell immunomonitoring in B cell–targeted therapies.
Novel MPC‐Based Fault Tolerant Tracking Control Against Sensor Faults
Authors: Li Jun , Zhang Dengfeng , Wang Zhiquan
Published: October 2018

The problem of active fault‐tolerant tracking control with control input and system output constraints is studied for a class of discrete‐time systems subject to sensor faults. A time‐varying fault‐tolerant observer is first developed to estimate the real system state from the faulty sensor output and control input signals. Then by using the estimated state at each time step, a model predictive control (MPC)‐based fault‐tolerant tracking control scheme is presented to guarantee the desired tracking performance and the given input and output constraints on the faulty system. In comparison with many existing fault‐tolerant MPC methods, its main contribution is that the proposed state estimator is designed by the simple and online numerical computation to tolerate the possible sensor faults, so that the regular MPC algorithm without fault information can be adopted for the online calculation of fault‐tolerant control signal. The potential recursive infeasibility and computational complexity due to the faults are avoided in the scheme. Additionally, the closed‐loop stability of the post‐fault system is discussed. Simulative results of an electric throttle control system verify the effectiveness of the proposed method.
Framework for Optimizing Chlorine and Byproduct Concentrations in Drinking Water Distribution Systems
Authors: Fisher Ian , Kastl George , Shang Feng , Sathasivan Arumugam
Published: October 2018

Recently developed water quality evaluation models can help water utilities explore disinfection options, determine the best treatment and approach, and save money in the long run.
Pilot‐Scale Application of Shotblast Dust for Phosphorus Removal
Authors: Baek Soyoung , Joo Sung Hee , Linne Douglas , Leon Sofia , Luciano Cecilia , Bailey Christopher , Su Chunming , Wan Yongshan
Published: October 2018

A novel use of waste material, called shotblast dust, in a pilot‐scale reactor may provide cost‐effective remediation for removing phosphorus contamination from water.
Thermal Sugar Bubbling Preparation of N‐Doped Porous Carbon for High‐Performance Solid‐State Zn‐Air Batteries
Authors: Chen Si , Chen Song , Zhang Jintao
Published: October 2018

The rational design of metal‐free carbon‐based bifunctional electrocatalysts for lowering the energy barrier of oxygen reactions in metal‐air batteries has a propelling effect on improving their overall performance. Herein, we reported the preparation of N‐doped porous carbon materials with a large specific surface area of over 1900 m2 g−1 via thermal bubbling of glucose in the presence of cyanuric acid and ammonia chloride. When used as electrocatalysts, the porous carbon exhibited excellent bifunctional electrocatalytic activities for both, the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). The potential gap (ΔE=EOER j=10‐EORR 1/2) between two reactions at the NPC‐1000 catalyst is 0.72 V, which is even lower than that of the commercial electrocatalyst (e. g., Pt+RuO2, ∼0.80 V). The good bifunctional catalytic activities render the fabrication of high‐performance rechargeable Zn‐air batteries. Specifically, the flexible all‐solid‐state Zn‐air battery assembled with NPC‐1000 as the air cathode exhibited good charge‐discharge stability and the voltage efficiency could be maintained about 58.6 % even after cycling for 50 h. Furthermore, no obvious voltage decay was observed under various bending, showing the good mechanical flexibility.
Group moral discount: Diffusing blame when judging group members
Authors: Vainapel Sigal , Weisel Ori , Zultan Ro'i , Shalvi Shaul
Published: October 2018

People lie more when they work as a group rather than alone. However, do people suspect and morally evaluate groups and individuals differently when they are suspiciously successful? In four experiments, we examine whether (a) suspiciously successful individuals and groups are judged and punished differently and (b) individual group members are judged differently from the group as one unit. Results suggest that people suspect successful groups and individuals to the same extent. However, group members are less likely to be suspected, judged negatively, punished, and reported on, when they are judged as separate individuals compared with as a group. The findings demonstrate a bias in judgment of group members, stemming from the method of evaluation—holistic or separate. We suggest that in order to minimize bias when judging misconduct by a group, the moral evaluation and punishment of all group members should be considered simultaneously.
Stereodivergent Synthesis of Carveol and Dihydrocarveol through Ketoreductases/Ene‐Reductases Catalyzed Asymmetric Reduction
Authors: Guo Jiyang , Zhang Rui , Ouyang Jingping , Zhang Feiting , Qin Fengyu , Liu Guigao , Zhang Wenhe , Li Hengyu , Ji Xiaohong , Jia Xian , Qin Bin , You Song
Published: October 2018

Chiral carveol and dihydrocarveol are important additives in the flavor industry and building blocks in the synthesis of natural products. Despite the remarkable progress in asymmetric catalysis, convenient access to all possible stereoisomers of carveol and dihydrocarveol remains a challenge. Here, we present the stereodivergent synthesis of carveol and dihydrocarveol through ketoreductases/ene‐reductases catalyzed asymmetric reduction. By directly asymmetric reduction of (R)‐ and (S)‐carvone using ketoreductases, which have Prelog or anti‐Prelog stereopreference, all four possible stereoisomers of carveol with medium to high diastereomeric excesses (up to >99 %) were first observed. Then four stereoisomers of dihydrocarvone were prepared through ene‐reductases catalyzed diastereoselective synthesis. Asymmetric reduction of obtained dihydrocarvone isomers by ketoreductases further provide access to all eight stereoisomeric dihydrocarveol with up to 95 % de values. In addition, the absolute configurations of dihydrocarveol stereoisomers were determined by using modified Mosher's method.
Bidentate Phosphanyl‐ and Arsanylboranes
Authors: Hegen Oliver , Braese Jens , Timoshkin Alexey Y. , Scheer Manfred
Published: October 2018

A new class of neutral bidentate ligands with pnictogenyl‐functional sites has been obtained. The reaction of tmeda⋅(BH2I)2 (1, tmeda=tetramethylethylendiamine) with different phosphanides yields the corresponding bidentate phosphanylboranes tmeda⋅(BH2PH2)2 (2 a), tmeda⋅(BH2PPh2)2 (2 b), and tmeda⋅(BH2tBuPH)2 (2 c). This reaction strategy could be further extended to synthesize the first bidentate arsanylborane tmeda⋅(BH2AsPh2)2 (3). Depending on the substituents on the phosphorus, these compounds form different AuI complexes, to build either polymeric tmeda⋅(BH2PH2AuCl)2 (4 a), or monomeric tmeda⋅(BH2PPh2AuCl)2 (4 b) products. These compounds form also neutral oligomeric group 13/15 chain‐like molecules by coordination to a boron moiety such as tmeda⋅(BH2PH2BH3)2 (5 a) and tmeda⋅(BH2AsPh2BH3)2 (5 b). DFT calculations provide insight into the differences between the syntheses of mono‐ and bidentate pnictogenylboranes.
Online monitoring and mass transfer modelling of the growth of Ni‐B nanoparticles in a reverse micelle system
Authors: Bahmanyar Amir , Pazuki Gholamreza , Nikazar Manouchehr
Published: October 2018

The growth of Ni‐B nanoparticles by chemical reduction of nickel acetate tetrahydrate (0.3M) using sodium borohydride (B/Ni = 2.5 molar ratio) in CTAB/n‐hexanol/water ternary reverse micelles was investigated. SEM studies showed that the synthesized nanoparticles within the reverse micelle range are more favourable in terms of microstructure and morphology. Nanoparticle growth has been controlled in the range of 0.83–5.59 nm · h−1 by the precise adjustment of mass fraction of surfactant in the oil phase (0.22–0.47 wt%) and the overall mass fraction of the aqueous phase (0.1–0.3 wt%) values. Particle growth was measured in situ using time resolved UV‐vis absorbance spectroscopy. In addition, a new correlation based on characteristic absorbance peaks of Ni‐B nanoparticles at wavelengths of 285 and 230 nm has been derived for this purpose. An accuracy of about 9 % on the nanoparticle average sizes with respect to sizes measured by dynamic light scattering (DLS) was found (R2 = 0.98). A diffusion controlled growth model involving effective diffusivity of reverse micelles (Deff − RM = 9.60 × 10−11 − 1.17 × 10−8 m2 · s−1) andripening parameter (K = 4.57 × 10−21 − 1.54 × 10−20 m2 · s−1) was developed to describe the growth behaviour of the nanoparticles. The experimental results were very close to the experimental results with slight errors (7–10 %). Finally, TEM micrographs of Ni‐B nanoparticles showed that particle growth as well as agglomeration can be effectively controlled by precise adjustment of each component in the reverse micelle technique.
Development of a concept of a seminar focusing on reading strategies developed following adapted model of participatory action research
Authors: Tolsdorf Yannik , Markic Silvija
Published: October 2018

Das Modell der Partizipativen Aktionsforschung zeigte Erfolge in der Entwicklung von Unterrichtsmaterialien und in der Professionalisierung von Lehrkräften. Ausgehend von den Anforderungen der Chemielehramtsausbildung mit den Fokussen auf Heterogenität, Diversität, Diagnostik und Förderung im Chemieunterricht wurde das Modell der Partizipativen Fachdidaktischen Aktionsforschung adaptiert und für die universitäre Ebene weiterentwickelt. Bei dem adaptierten Modell steht die Bildung eines Einwicklungsteams im Fokus, das in einem kommunikativen Austausch eine universitäre Lehrveranstaltung der Chemiedidaktik weiterentwickelt. In diesem Artikel wird das weiterentwickelte Modell vorgestellt und an einem Beispiel beschrieben.
Application of Polyaniline for Li‐Ion Batteries, Lithium–Sulfur Batteries, and Supercapacitors
Authors: Luo Yani , Guo Ruisong , Li Tingting , Li Fuyun , Liu Zhichao , Zheng Mei , Wang Baoyu , Yang Zhiwei , Luo Honglin , Wan Yizao
Published: October 2018

Conducting polyaniline (PANI) exhibits interesting properties, such as high conductivity, reversible convertibility between redox states, and advantageous structural feature. It therefore receives ever‐increasing attention for various applications. This Minireview evaluates recent studies on application of PANI for Li‐ion batteries (LIBs), Li–S batteries (LSBs) and supercapacitors (SCPs). The flexible PANI is crucial for cyclability, especially for buffering the volumetric changes of electrode materials, in addition to enhancing the electron/ion transport. Furthermore, PANI can be directly used as an electroactive component in electrode materials for LIBs or SCPs and can be widely applied in LSBs due to its physically and chemically strong affinity for S and polysulfides. The evaluation of studies herein reveals significant improvements of electrochemical performance by physical/chemical modification and incorporation of PANI.
Molten‐Salt‐Assisted Synthesis of Hierarchical Porous MnO@Biocarbon Composites as Promising Electrode Materials for Supercapacitors and Lithium‐Ion Batteries
Authors: Zhang Hai , Zhang Ze , Luo Ji‐Di , Qi Xing‐Tao , Yu Ji , Cai Jian‐Xin , Yang Zhen‐Yu
Published: October 2018

Biomass‐derived carbon composites (e.g., metal oxide/biocarbon) have been used as promising electrode materials for energy storage devices owing to their natural abundance and simple preparation process. However, low loading content/inhomogeneous distribution of metal oxides and inefficient cracking of biocarbon (BC) are intractable obstacles that impede the efficient utilization of biomass. In this work, hierarchical porous MnO/BC composites were prepared by a facile molten‐salt‐assisted strategy based on the superior salt‐water absorption ability of agaric. The addition of NaCl induces a liquid reaction medium by formation of a molten salt mixture at high temperature to effectively realize the activation and cracking of the bulk carbon, and it also acts as a recyclable sacrificial template to form mesopores and macropores in the as‐prepared hierarchical porous MnO/BC composites. The highly porous and uniform BC framework effectively enhances ion diffusion and electron‐transfer ability, serves as a protective layer to prevent fracturing and agglomeration of MnO, and thus enables superior rate performance and cycling stability of the MnO/BC composite for both supercapacitor electrodes (94 % capacity retention at 20 mA cm−2 after 5000 cycles) and lithium‐ion battery anodes (783 mA h g−1 after 1000 cycles). Notably, considering the simple and low‐cost preparation process, this work opens a promising avenue for the large‐scale production of advanced metal oxide/BC hybrid electrode materials for electrochemical energy storage.
Development of Betaine‐Based Sustainable Catalysts for Green Conversion of Carbohydrates and Biomass into 5‐Hydroxymethylfurfural
Authors: Feng Yunchao , Li Mengzhu , Gao Zhebang , Zhang Xin , Zeng Xianhai , Sun Yong , Tang Xing , Lei Tingzhou , Lin Lu
Published: October 2018

Renewable and sustainable betaine‐based catalysts (BX) derived from the betaine sugar industry or ChCl were developed for the production of 5‐hydroxymethylfurfural (HMF) from various carbohydrates. The HMF yields in the BX‐based media reached up to 88 %, 66 %, 37 % and 53 %, for the conversion of fructose, glucose, cellulose, and lignocellulosic biomass, respectively. In addition, choline‐O‐sulfate was synthesized and demonstrated to be an efficient catalyst for the conversion of fructose to HMF. From the perspective of green and sustainable chemistry, this work demonstrates benefits not only in the preparation of sustainable catalysts but also the green production of HMF from biomass.
Soil drivers of local‐scale tree growth in a lowland tropical forest
Authors: Zemunik Graham , Davies Stuart J. , Turner Benjamin L.
Published: October 2018

Soil nutrients influence the distribution of tree species in lowland tropical forests, but their effect on productivity, especially at local scales, remains unclear. We used tree census, canopy occupancy, and soil data from the Barro Colorado Island (BCI; Panama) 50‐ha forest dynamics plot to investigate the influence of soil nutrients and potential toxins on aboveground tree productivity. Growth was calculated as the increase in diameter of 150,000 individual stems ≥1 cm diameter at breast height, representing 207 species. The effects of soil variables and other strong predictors of growth (e.g., light) were estimated using hierarchical, linear, mixed‐effects models. Growth was weakly positively associated with phosphorus (P), particularly for understory tree species that are typically considered to be limited by light. In contrast, growth was strongly negatively related to manganese (Mn) and aluminum (Al), although the latter effect was confounded by strong correlations between Al and other soil variables. The negative response to increasing Mn (and Al) suggests a toxicity effect due to solubilization and uptake of amorphous pools of metal oxides in the soil. These results show that P limits tropical tree growth at local scale on BCI, but that toxic metals represent an even greater constraint on productivity.
Studying safe storage time of orange peel (Citrus reticulata) using high‐throughput sequencing and conventional pure culture
Authors: Wang Fu , Chen Lin , Liu Sujuan , Li Fengqing , Zhang Xin , Chen Hongping , Liu Youping
Published: October 2018

Aspergillus is a fungal genus widely studied all over the world because some species are known allergens and opportunistic human pathogens. The dynamic growth of Aspergillus is a prerequisite for establishing safe storage time of orange peel. In this paper, high‐throughput sequencing technique was used for the first time to analyze the diversity and structure of fungi in the same batch of samples at different periods of time, and 20 batches of fresh orange peel and 56 batches of dried peel were verified. Results shown that the orange peel gradually began to grow Aspergillus fungal after storing for 240 days, and the abundance became maximum at 270 days and then decreased. These results suggest the safe storage time should be from January to August. And orange peel should be dried in August to prevent rapid propagation or metabolic toxicity production of Aspergillus fungi.
Resource governance and the politics of the social: Ordering in and by socio‐ecological systems
Authors: Valve Helena
Published: October 2018

In studies of natural resource governance, agency is commonly treated as a property that evolves in conditions of socio‐ecological systems (SESs). While theSESframework has established its position within a multidisciplinary scholarship, it remains controversial. Critical scholars note that the social component has been left under‐theorised. Yet, it is argued that once developed, the framework can provide a useful foundation for studying human–environment relations. This article critically examines such a position. Drawing from actor‐network theory, it analyses the assumptions theSESframework makes about the social forms constitutive for natural resource governance. The focus is on the entities in terms of which governance and management are envisioned to evolve. The analysis shows that the descriptions ofSESdynamics often treat social forms as unambiguous and a priori existing. The paper argues that the material ordering that is enacted downplays potentials of politics. Management and governance of natural resources rest on demarcations that are not supposed to be challenged. At the same time radical un‐restrictedness is claimed to co‐exist and to open up potentials for social learning. The promise of management enacted by theSESframework seems thus to be based on a very particular kind of fluctuation between opening up and closing down of system spaces.
Abnormal phasic activity in saliency network, motor areas, and basal ganglia in Parkinson's disease during rhythm perception
Authors: Vikene Kjetil , Skeie Geir‐Olve , Specht Karsten
Published: October 2018

Behavioral studies indicate that persons with Parkinson's disease have complexity dependent problems with the discrimination of auditory rhythms. Furthermore, neuroimaging studies show that rhythm processing activates many brain areas that overlap with areas affected by Parkinson's disease (PD). This study sought to investigate the neural correlates of rhythm processing in PD and healthy controls, with a particular focus on rhythmic complexity. We further aimed to investigate differences in brain activation during initial phases of rhythm processing. Functional magnetic resonance imaging was used to scan 15 persons with Parkinson's disease and 15 healthy controls while they listened to musical rhythms with two different levels of complexity. Rhythmic complexity had no significant effect on brain activations, but patients and controls showed differences in areas related to temporal auditory processing, notably bilateral planum temporale and inferior parietal lobule. We found indications of a particular sequential or phasic activation pattern of brain activity, where activity in caudate nucleus in the basal ganglia was time‐displaced by activation in the saliency network—comprised of anterior cingulate cortex and bilateral anterior insula—and cortical and subcortical motor areas, during the initial phases of listening to rhythms. We relate our findings to core PD pathology, and discuss the overall, rhythm processing related hyperactivity in PD as a possible dysfunction in specific basal ganglia mechanisms, and the phasic activation pattern in PD as a reflection of a lack of preparatory activation of task‐relevant brain networks for rhythm processing in PD.
Mitochondrial Oxidative Stress and Antioxidants Balance in Fatty Liver Disease
Authors: García‐Ruiz Carmen , Fernández‐Checa José C.
Published: October 2018

Fatty liver disease is one of the most prevalent forms of chronic liver disease that encompasses both alcoholic liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD). Alcoholic steatohepatitis (ASH) and nonalcoholic steatohepatitis (NASH) are intermediate stages of ALD and NAFLD, which can progress to more advanced forms, including cirrhosis and hepatocellular carcinoma. Oxidative stress and particularly alterations in mitochondrial function are thought to play a significant role in both ASH and NASH and recognized to contribute to the generation of reactive oxygen species (ROS), as documented in experimental models. Despite the evidence of ROS generation, the therapeutic efficacy of treatment with antioxidants in patients with fatty liver disease has yielded poor results. Although oxidative stress is considered to be the disequilibrium between ROS and antioxidants, there is evidence that a subtle balance among antioxidants, particularly in mitochondria, is necessary to avoid the generation of ROS and hence oxidative stress. Conclusion: As mitochondria are a major source of ROS, the present review summarizes the role of mitochondrial oxidative stress in ASH and NASH and presents emerging data indicating the need to preserve mitochondrial antioxidant balance as a potential approach for the treatment of human fatty liver disease, which may pave the way for the design of future trials to test the therapeutic role of antioxidants in fatty liver disease.
Research on and Development of Inquiry‐Type Chemistry Laboratories in Israel
Authors: Hofstein Avi , Dkeidek Iyad , Katchevitch Dvora , Nahum Tami Levy , Kipnis Mira , Navon Oshrit , Shore Relly , Taitelbaum Dorit , Mamlok‐Naaman Rachel
Published: October 2018

Over a period of more than 60 years, the chemistry laboratory has been extensively and comprehensively researched and hundreds of research papers, reviews, and doctoral dissertations have been published, investigating the laboratory as a unique learning environment. However, there were challenges and pedagogical questions regarding its educational effectiveness and benefits for teaching and learning chemistry. At the beginning of the 21st century there was a call to rethink (and research) the goals for learning chemistry in the laboratory. This is especially applicable in an era in which we are trying to enhance the goal of teaching “chemistry for all students” and/or for the benefit of what is fondly called “future citizens”. Working for more than 15 years with colleagues and students, we researched the potential of establishing an inquiry‐type chemistry laboratory for developing high‐order learning skills, namely, skills for the future or skills for life, including metacognitive and argumentative skills, and the ability of students to ask relevant questions resulting from an inquiry‐type chemistry laboratory.
Weighted least square analysis method for free energy calculations
Authors: Hu Dan , Guan Xiaoqing , Wang Yukun
Published: October 2018

Free energy calculation is an efficient way for studying rare event dynamics. For a complex rare event dynamics, multiple reaction coordinates may be required to describe the transition path between equilibrium states. Theoretically, a one‐dimensional sampling along the transition path can provide sufficient information to calculate the potential of mean force (PMF) along the transition path. In the widely used free energy analysis method Wham, the sample data are divided into a series of bins to calculate PMF. However, bin segmentation in Wham is coupled with the umbrella potentials applied in each window, because each umbrella potential is assumed to have a close value for all sample points in each bin. This coupling makes it difficult to perform one‐dimensional bin segmentation along the transition path when multivariable umbrella potentials are used in sampling. Here, we develop a weighted least square analysis method (Welsam) to take the place of Wham for free energy analysis. In the new method Welsam, bin segmentation is decoupled from application of umbrella potentials. As a result, it becomes very convenient to perform one‐dimensional bin segmentation and calculate one‐dimensional PMF along the transition path. Our simulation results suggest that Welsam has a comparable statistical error with Wham. Furthermore, Welsam can be used to reduce waste of sample data obtained during exploration of reaction coordinates. © 2018 Wiley Periodicals, Inc.
Efficacy and adverse events of five targeted agents in the treatment of advanced or metastatic non‐small‐cell lung cancer: A network meta‐analysis of nine eligible randomized controlled trials involving 5,059 patients
Authors: Liu Gui‐Feng , Li Xue‐Feng , Yu Shao‐Nan , Miao Ying‐Ying , Zhang Shu‐Hua
Published: October 2018

Recently, targeted agents were reported to improve overall survival, progression‐free survival (PFS), response rate, and quality of life compared with cytotoxic chemotherapies, which provides hope for the treatment of non‐small‐cell lung cancer (NSCLC). The network meta‐analysis is applied to compare the efficacies and adverse events of five targeted agents (erlotinib, gefitinib, vandetanib, dacomitinib, and icotinib) for advanced or metastatic NSCLC. Nine eligible randomized controlled trials from PubMed and Cochrane Library database were included. Weighted mean difference, odds ratio, and surface under the cumulative ranking curve (SUCRA) values were evaluated for the efficacy and adverse events of the five targeted agents in the treatment of NSCLC. With regard to efficacy, the overall response rate (ORR) of advanced or metastatic NSCLC patients treated with gefitinib was relatively higher than those treated with placebo. Compared with patients treated with placebo, the disease control rate (DCR) of patients treated with erlotinib and with gefitinib was relatively higher. Furthermore, in terms of PFS and DCR, the SUCRA value of icotinib was the highest among the five targeted drugs. With regard to ORR, the SUCRA value of gefitinib was the highest among the five targeted drugs. In terms of fatigue, rash, and cough, erlotinib had the lowest SUCRA value, whereas vandetanib exhibited the lowest SUCRA value in terms of diarrhea. Our study suggests that the efficacies of gefitinib and icotinib for advanced or metastatic NSCLC were comparatively better, whereas the toxicities of erlotinib and vandetanib were relatively greater.
Identification of unexpected unlabeled N,N‐dimethylamide formation in the synthesis of deuterated fragment of ribociclib by a HATU‐mediated coupling reaction
Authors: Gai Kuo , Liu Baomin , Zhang Yinsheng
Published: October 2018

Starting from N,N‐dimethylamine and D2O, deuterated fragment of ribociclib was synthesized for use as a mass spectroscopy internal standard. Furthermore, systematic studies on D0 (unlabeled material) formation during the amidation reaction were performed, leading to the identification of a coupling reagent, HATU (O‐(7‐azabenzotriazol‐1‐yl)‐N,N,N′,N′‐tetramethyluronium hexafluorophosphate), as main cause. Finally, an alternative route was designed using EDCI/HOBT as coupling reagents to produce the desired deuterated compound without D0 residue.
Replication of the Interaction of PRKG1 and Trauma Exposure on Alcohol Misuse in an Independent African American Sample
Authors: Hawn Sage E. , Sheerin Christina M. , Webb Bradley T. , Peterson Roseann E. , Do Elizabeth K. , Dick Danielle , Kendler Kenneth S. , Bacanu Silviu‐Alin , Amstadter Ananda B.
Published: October 2018

In the present study, we sought to replicate recent findings of Polimanti et al. (2017), who conducted a genome‐wide gene‐by‐environment interaction study (GEWIS) and identified a gene‐by‐trauma interaction that predicts alcohol misuse among African Americans.  Consistent with the findings published by Polimanti and colleagues, results of the current study demonstrated an interaction effect, b = 0.41, of trauma exposure and rs1729578 in the intron of PRKG1 on alcohol misuse in a subsample of ancestral African Americans. The minor allele (rs1729578*C) was positively associated with increased alcohol use disorder symptoms in trauma‐exposed subjects and negatively associated in non‐trauma‐exposed subjects.  This effect, however, was only significant for one out of three alcohol outcome measures we investigated, suggesting the interaction may be most salient when predicting higher severity of alcohol misuse. Additionally, the effect did not remain significant after we accounted for testing the effect on three different outcome variables. Also in line with the original study, the gene‐by‐environment effect was not demonstrated among the ancestral European subsample.  The findings suggest this gene variant may increase an individual's susceptibility to environmental influences, both adverse and supportive.
Climate impacts on soil erosion and muddy flooding at 1.5 versus 2°C warming
Authors: Mullan Donal , Matthews Tom , Vandaele Karel , Barr Iestyn D. , Swindles Graeme T. , Meneely John , Boardman John , Murphy Conor
Published: October 2018

Following the 2015 ‘Paris Agreement’ that seeks to contain global mean temperature increase (GMTI) to well below 2°C and more ambitiously within 1.5°C, recent studies have begun assessing the response of various sectors to these levels of warming. Most studies have so far concentrated on temperature‐sensitive sectors. Given the links between a warmer atmosphere and rainfall intensity, there is also a need to examine impact sectors driven primarily by changing rainfall characteristics. One example is soil erosion and muddy flooding from agricultural land, which damages the natural and built environment. Using a case‐study hillslope in eastern Belgium—an area particularly impacted by muddy floods—this study examines (a) whether soil erosion and muddy flooding will increase in the future; and (b) whether containing GMTI to 1.5°C would help limit the problem versus 2°C. The Water Erosion Prediction Project model was used to simulate muddy flooding for the present‐day and under a range of future scenarios derived from climate models that correspond to 1.5 and 2°C GMTI. The main findings reveal no statistically significant differences between muddy flooding at 1.5 and 2°C GMTI. Limiting GMTI to 1.5°C therefore does not appear to make much difference to soil erosion and muddy flooding, because the timing of changing rainfall intensity does not always follow clear patterns with increased warming. Regardless of the magnitude of future warming, an earlier and longer muddy flooding season is projected—highlighting that mitigation measures should be continually adapted to remain resilient to climate change.
Impact of Comonomer Chemistry on Phase Behavior of Polymerizable Lyotropic Ionic Liquid Crystals: A Pre‐ and Post‐Polymerization Study
Authors: Goujon Nicolas , Dumée Ludovic F. , Byrne Nolene , Bryant Gary , Forsyth Maria
Published: October 2018

The design and characterization of polymerizable lyotropic ionic liquid crystals with an intact alkyl chain bilayer are described. The bilayer is left intact to enable further inclusion of peptide‐based channels to mimic biological protein membranes for potential separation applications. Impact of comonomer concentration and chemistry on the mesophase formed pre‐ and post‐polymerization is characterized. An optimum comonomer concentration of 20 wt% is found for the poly(ethylene glycol) diacrylate (PEGDA) system, before full disruption of the discontinuous cubic phase occurs. Little impact on the discontinuous cubic phase is observed by varying comonomer chemistry from PEGDA to either poly(ethylene glycol) dimethacrylate or 2‐hydroxyethyl acrylate, with exception of variation in the thermal stability of the resulting mesophase. Surprisingly, the use of 2‐hydroxyethyl methacrylate as comonomer results in formation of the 2D hexagonal phase, which is of interest for the design of biological protein membranes. Unfortunately, mesostructure retention is not observed in any systems studied. A sequence of structural changes, modeled as a change from a spherical micelle to a cylindrical micelle, and to finally a lamellar architecture, is rather observed using in situ small‐angle X‐ray scattering polymerization measurements, suggesting a reduction of the headgroup area, likely caused by cross‐linking of the acrylate moiety.
An extended technique for order preference by similarity to ideal solution group decision‐making method with linguistic interval‐valued intuitionistic fuzzy information
Authors: Garg Harish , Kumar Kamal
Published: October 2018

Linguistic intuitionistic fuzzy set (LIFS) is an efficient theory to represent the data in form of membership degrees in a qualitative rather than the quantitative aspects. But in sometimes, it is preferable by the decision‐maker to give their preferences in terms of interval numbers rather than real numbers. To address this, the present manuscript extends the theory of LIFS to linguistic interval‐valued intuitionistic fuzzy set (LIVIFS) by expressing the degrees of membership and non‐membership by the interval‐valued linguistic terms. Under this environment, some measures of distances have been proposed to measuring the uncertainties in the data. The characteristics and their desirable relations have also been stated. Further, based on these measures, an extended technique for order preference by similarity to ideal solution method has been presented under the LIVIFS environment by different pairs of decision‐makers and their corresponding priority levels. The study has been validated through a numerical example.
Telemedicine vs Office Visits in a Movement Disorders Clinic: Comparative Satisfaction of Physicians and Patients
Authors: Hanson Ryan E. , Truesdell Marisa , Stebbins Glenn T. , Weathers Allison L. , Goetz Christopher G.
Published: October 2018

Objective

To compare patient and physician satisfaction between home‐based telemedicine visits and office visits for follow‐up care within a movement disorders program.

Methods

Patients were offered telemedicine visits as follow‐up care. After telemedicine visits, a questionnaire of items along a 10‐point Likert Scale (10 = most satisfied) assessed patient and overall physician satisfaction, comparing the experience to past in‐office visits.

Results

Patients and physicians were highly satisfied with the telemedicine experience, both groups having median endorsement scores of 9.25 and 10.0, respectively (response range 6–10), and furthermore, favoring future telemedicine visits when feasible. Although some assessments could not be performed (postural stability, rigidity), physicians likewise favored having future telemedicine visits (median score 10, range 5.0–10).

Conclusions

This direct comparison of patient satisfaction with telemedicine visits to previously experienced office visits strongly supports telemedicine care, with patients highlighting convenience, time, and expense. Despite some limitations with telemedicine, physicians expressed highly rated quality‐of‐service provided.
Habitual exercisers versus sedentary subjects with Parkinson's Disease: Multimodal PET and fMRI study
Authors: Sacheli Matthew A. , Murray Danielle K. , Vafai Nasim , Cherkasova Mariya V. , Dinelle Katie , Shahinfard Elham , Neilson Nicole , McKenzie Jessamyn , Schulzer Michael , Appel‐Cresswell Silke , McKeown Martin J. , Sossi Vesna , Jon Stoessl A.
Published: October 2018

Background

The benefits of exercise in PD have been linked to enhanced dopamine (DA) transmission in the striatum.

Objective

To examine differences in DA release, reward signaling, and clinical features between habitual exercisers and sedentary subjects with PD.

Methods

Eight habitual exercisers and 9 sedentary subjects completed [11C]raclopride PET scans before and after stationary cycling to determine exercise‐induced release of endogenous DA in the dorsal striatum. Additionally, functional MRI assessed ventral striatum activation during reward anticipation. All participants completed motor (UPDRS III; finger tapping; and timed‐up‐and‐go) and nonmotor (Beck Depression Inventory; Starkstein Apathy Scale) assessments.

Results

[11C]Raclopride analysis before and after stationary cycling demonstrated greater DA release in the caudate nuclei of habitual exercisers compared to sedentary subjects (P < 0.05). Habitual exercisers revealed greater activation of ventral striatum during the functional MRI reward task (P < 0.05) and lower apathy (P < 0.05) and bradykinesia (P < 0.05) scores versus sedentary subjects.

Conclusions

Habitual exercise is associated with preservation of motor and nonmotor function, possibly mediated by increased DA release. This study formulates a foundation for prospective, randomized controlled studies. © 2018 International Parkinson and Movement Disorder Society
Doubly singular boundary value problems with derivative dependent source function: A fast‐converging iterative approach
Authors: Roul Pradip
Published: October 2018

In this paper, a fast‐converging recursive scheme is presented to approximate the solution of a class of derivative dependent doubly singular boundary value problems (DDSBVP). First, the original problem is reformulated as an equivalent integral equation. The resulting integral equation is then efficiently tackled by an improved homotopy analysis method (IHAM). This method contains a parameter, which greatly accelerates the convergence of the series solution. The convergence of the method is carried out. To illustrate the efficiency and accuracy of the proposed recursive approach, we consider three nonlinear examples, including one physical model problem, which describes stress distribution on a rotationally shallow membrane cap. Results show that our method excels over the existing methods.
The motion characteristics of the double‐pendulum system with skew walls
Authors: Lampart Marek , Zapoměl Jaroslav
Published: October 2018

Many components of machines and other technological devices (chains and bodies hanging on the ropes) can be modeled as multiple pendulums situated in tubes or holes of limited space. The investigation of motion of such systems represents the substance of many real technological problems; therefore, it stirred up motivation to perform research on vibration of a double pendulum situated between two skew rigid walls. The analyzed system was set into motion by the horizontal movement of its suspending. The results of the simulations show that the system can exhibit both the regular and chaotic movements depending on the excitation frequency. The development of the computational model, which is applicable for more complex investigations, and learning more on the motion character of a double pendulum, the movement of which is limited by skew walls, are the principal contributions of the presented article.
Automatic tumor segmentation in breast ultrasound images using a dilated fully convolutional network combined with an active contour model
Authors: Hu Yuzhou , Guo Yi , Wang Yuanyuan , Yu Jinhua , Li Jiawei , Zhou Shichong , Chang Cai
Published: October 2018

Purpose

Due to the low contrast, blurry boundaries, and large amount of shadows in breast ultrasound (BUS) images, automatic tumor segmentation remains a challenging task. Deep learning provides a solution to this problem, since it can effectively extract representative features from lesions and the background in BUS images.

Methods

A novel automatic tumor segmentation method is proposed by combining a dilated fully convolutional network (DFCN) with a phase‐based active contour (PBAC) model. The DFCN is an improved fully convolutional neural network with dilated convolution in deeper layers, fewer parameters, and batch normalization techniques; and has a large receptive field that can separate tumors from background. The predictions made by the DFCN are relatively rough due to blurry boundaries and variations in tumor sizes; thus, the PBAC model, which adds both region‐based and phase‐based energy functions, is applied to further improve segmentation results. The DFCN model is trained and tested in dataset 1 which contains 570 BUS images from 89 patients. In dataset 2, a 10‐fold support vector machine (SVM) classifier is employed to verify the diagnostic ability using 460 features extracted from the segmentation results of the proposed method.

Results

Advantages of the present method were compared with three state‐of‐the‐art networks; the FCN‐8s, U‐net, and dilated residual network (DRN). Experimental results from 170 BUS images show that the proposed method had a Dice Similarity coefficient of 88.97 ± 10.01%, a Hausdorff distance (HD) of 35.54 ± 29.70 pixels, and a mean absolute deviation (MAD) of 7.67 ± 6.67 pixels, which showed the best segmentation performance. In dataset 2, the area under curve (AUC) of the 10‐fold SVM classifier was 0.795 which is similar to the classification using the manual segmentation results.

Conclusions

The proposed automatic method may be sufficiently accurate, robust, and efficient for medical ultrasound applications.
User identification via neural network based language models
Authors: Phan Tien D. , Zincir‐Heywood Nur
Published: October 2018

Identifying compromised accounts on online social networks that are used for phishing attacks or sending spam messages is still one of the most challenging problems of cyber security. In this research, the authors explore an artificial neural network‐based language model to differentiate the writing styles of different users on short text messages. In doing so, the aim is to be able to identify compromised user accounts. The results obtained indicate that one can learn the language model on one dataset and can generalize it to different datasets to identify users with high accuracy and low false alarm rates without any modification to the language model.
Enhanced breakdown strength and energy storage of PVDF‐based dielectric composites by incorporating exfoliated mica nanosheets
Authors: Fu Yunjin , Wang Yaxuan , Wang Shan , Gao Zhaodongfang , Xiong Chuanxi
Published: October 2018

The development of flexible and high‐performance dielectric materials is of critical importance in energy storage devices. Since energy density of a dielectric capacitor is determined by the dielectric constant and breakdown strength, in this work, a simple and effective way is provided to increase the energy storage density of polymer matrix dielectric film via adding exfoliated mica nanosheets. Few‐layered mica nanosheets were successfully exfoliated by a facile one‐step method and incorporated with Poly(vinylidene fluoride) (PVDF) matrix. The mica nanosheets could act as the insulating barriers, which help to increase the breakdown strength of the PVDF/mica composites. The maximum discharged energy density of the prepared composite film was 7.93 J cm−3 at 450 MV m−1 with only 5 vol% of mica nanosheets, which is about three times higher than pure PVDF. This study introduced an economic and effective approach to get flexible and high energy density polymer composite films and broadened the application of mica. POLYM. COMPOS., 2018. © 2018 Society of Plastics Engineers