bluuebunny/crossref_metadata_2025 huggingface dataset:
COMPARATIVE ANALYSIS OF METHODS FOR RISK ASSESSMENT - “KINNEY” AND “AUVA”
Authors: Stanković Milena , Stanković Vladana
Published: March 2019

Individuals, entire economy and society are exposed to risks more than ever. The problem of occupational safety and health has been present from the moment of origin of labour and it has been dealt with in line with the overall development of society. For this reason,different methods and matrices for risk assessment have been developed. The subject of this study is to review the methods of risk assessment, as well as to apply these methods at the workplace where dangers and hazards occur. The aim of the study was to use KINNEY and AUVA methods for assessing risk for the workplace of Operating Engineer - Occupational Safety, Environmental Safety and Fire Protection, and to perform a comparative analysis of with the aim to state possible advantages or disadvantages of chosen methods.
Key words:the risk assessment, methods of risk assessment, KINNEY method,AUVA method.
Perceived Implication of Climate Change on Fish Farming in Ibarapa Region of Oyo State, Nigeria
Authors: Bankole A.  F. , Ayanboye A. O. , Adeosun O. , Osuntade O. B. , Adelodun O. B.
Published: March 2019

The present study revealed the impact of climate change on fish farming business in Ibarapa region, Oyo State Nigeria during January to June 2017. Majority of the respondents were male (93.4%) whereas 6.6% were female. Some of the respondents (25%) have been in fish farming business for about 20 years. Major sources of water were deep well and bore-hole. The various constraints encountered in the course of the business were low water availability (25.0%), feeding cost (20.0%), weather problem (13.3%) and funds (11.7%). On awareness/perception of respondents on climate change, 75% of the farmers were aware of change in the climate phenomenon, which was basically through personal experience (33.2%). The perceived climate change factors are; drastic changes in weather condition (50%), increased incidence of drought (18.3%), heavy storms and increased incidence of flooding had 6.7% respectively, poor fish harvest (5%) was considered as the least factor on impacts of climate change.
Effect of Soil Compaction and Bulk Density on the Growth and Yield of Soybean (Glycine max) on Sandy Clay Loam Soil of the Semi-arid Region of Northern Nigeria as Influenced by Tractor Wheel Traffic
Authors: Dauda Abdu , Usman Bukar
Published: March 2019

Soil compaction from farm machinery is an environmental problem. The effect of compaction on plant growth and yield depends on the crop grown and the environmental conditions that crop encounters. The effect of compaction from tractor traffic on soybean (Glycine max), variety TGX1448-2E, on a sandy clay loam soil in the semi-arid region of northern Nigeria was investigated for two growing seasons, 2015 and 2016. A randomized complete block design of the field of plots with treatments of 0,5,10, 15 and 20 passes of a tractor MF 390 was used. Each treatment was replicated three times. The soil bulk density, penetration resistance and soil moisture content for each applied load were measured and the yield from each treatment was determined.  Agronomic treatments were kept the same for all plots in both 2015 and 2016. Results showed increased soil bulk density, penetration resistance and soil moisture content with increased tractor passes. Highest grain yield was obtained at 5 tractor passes with a mean bulk density of 1.76 Mgm,-3 penetration resistance 1.70 MPa and moisture content 13.37% with a mean yield of 2568 kgha-1 and lowest was obtained from 20 tractor passes were 340 kgha-1. Statistical models were used to predict yield as a function of bulk density, penetration resistance,   moisture content, contact pressure, and a number of tractor traffic passes. Grain yield with respect to moisture content gave the best yield prediction (r2 = 0.94).
Antimicrobial and Antioxidant Properties of kaempferol-3-O-glucoside and 1-(4-Hydroxyphenyl)-3-phenylpropan-1-one Isolated from the Leaves of Annona muricata (Linn.)
Authors: Taiwo Festus O. , Oyedeji Olaoluwa , Osundahunsi Moyosore T.
Published: March 2019

Aim: To evaluate the antimicrobial and antioxidant activities of bioactive compounds isolated from Annona muricata (Linn.) leaf extract.

Study Design: In vitro antimicrobial assay of bioactive compounds isolated from solvent fractions of plant leaf extract against selected clinical bacterial and fungal isolates. Antioxidant assay of plant leaf extract.

Place and Duration of Study: All the work was carried out in the Departments of Chemistry and Microbiology, Obafemi Awolowo University, Ile-Ife, Nigeria between March, 2015 and January, 2016.

Methodology: Isolation of bioactive compounds was by column and thin layer chromatographic techniques. Isolated compounds were characterized by nuclear magnetic resonance spectroscopic analysis. Antimicrobial activities were evaluated by disc diffusion and broth microdilution methods while antioxidant activity was investigated using the 2,2-dipheny-1-picrylhydrazyl (DPPH) radical-scavenging assay.

Results: Two compounds kaempferol-3-O-glucoside (1) and 1-(4-Hydroxyphenyl)-3-Phenylpropan-1-one (2) were isolated from the ethyl acetate fraction of leaf extract of A. muricata. The two compounds showed broad spectrum antimicrobial activities with zones of inhibition ranging from 26.00 ± 1.73 to 31 ± 1.00 mm and 17.33 ± 1.15 to 31.33 ± 1.15 mm respectively, for compounds 1 and 2 for the test bacteria species and 15.33 ± 1.15 to 31.33 ± 1.15 mm and 17.67 ± 0.58 to 29.67 ±1.53 mm respectively, for compounds 1 and 2 for the test fungi. Minimum inhibitory concentrations ranged between 0.625-5.00 µg/mL and 1.25-5.00 µg/ml respectively, for compounds 1 and 2. Minimum bactericidal concentrations ranged between 2.5-10.00 µg/mL for both compounds which compared favourably with the reference drugs used. DPPH radical-scavenging activities were IC50 = 13.41 ± 0.64 µg/mL and 7.42 ± 0.90 µg/mL for compounds 1 and 2 respectively, compared with IC50 = 51.99 ± 1.44 µg/ml obtained for the standard ascorbic acid. The results show that both isolated compounds from A. muricata leaf possess in vitro antimicrobial and antioxidant properties and they may be useful as active ingredients in antimicrobial drug formulations and as agents for the control of free radical-related pathological disorders.
Psychometric Properties of Iranian Version of Clustera Personality Disorder Questionnaire
Authors: Farokhi Nazanin , Kashni Farah Lotfi , Vaziri Shahram
Published: March 2019

Objective: This study was conducted to determining psychometric properties of Cluster A personality Disorder Questionnaire in Iran.

Methods: This was a methodology study. Statistical population consisted of 1375 students of Islamic Azad University North Branch. Central Branch, Roudehen Branch and Karaj Branch selected using random sampling method. Of completed 1375 questionnaires, 1303 questionnaires were selected because of invalid and malformed collected questionnaires. Data were analyzed using descriptive statistics-mean, standard deviation inferential statistics- determination coefficient, and Cronbach’s alpha- to examine validity and reliability of test; Millon Personality Disorder Questionnaire considered as external benchmark. In addition, t and z tests were used for standardization.

Findings: Results showed the obtained Cronbach’s alpha for subscales including Paranoid, Schizoid, and Schizotypal equal to 0.610- 0.674 and 0.650 respectively. Internal consistency of questionnaire items was significant based on Cronbach’s alpha at level of 0.05 (P<0.005) indicating internal stability, validity and reliability of test. Evidences from simultaneous validity correlation indicated positive and significant correlation between scores of two tests.

Discussion and Conclusion: It can be stated in accordance with the results obtained from study that Cluster A Personality Disorder Questionnaire is a valid and reliable instrument to diagnose clinical symptoms of cluster A personality disorder in Iranian community.
Surface Passivation toward Highly Stable Mn4+‐Activated Red‐Emitting Fluoride Phosphors and Enhanced Photostability for White LEDs
Authors: Zhou Yayun , Song Enhai , Deng Tingting , Wang Yuanjing , Xia Zhiguo , Zhang Qinyuan
Published: March 2019

Mn4+‐activated red‐emitting fluoride phosphors are indispensable candidates for white light emitting diodes (WLEDs) with enhanced color rendition, however, their intrinsic hydrolysis characteristics seriously restricted the durability applications. Here, a facile and general postsynthetic hydrogen peroxide (H2O2) surface passivation strategy is proposed to treat the K2XF6:Mn4+ (KXF, X = Ti, Si, Ge) phosphors, in which a Mn4+‐rare surface protective layer appears and further covers the corresponding particles. The environment moisture can be effectively isolated by the Mn4+‐rare surface passivation layer with low solubility, which will be sacrificed to protect the phosphor particles even if under extreme hydrolysis conditions. The relative external quantum efficiency of the optimized phosphors still maintains over 96% after the passivation treatment, and the relative luminous intensity still remain 97% even when soaked in water after 12 h. The correlated color temperature of high‐power WLEDs fabricated by the passivated phosphors has no remarkable change during aging process (100 days) in the high temperature (85 °C) and high humidity atmosphere (85%). It is expected that such a surface‐redox strategy can be expanded to other doped materials systems, and also opening a new perspective for the development of luminescence materials with enhanced surface stability and device duration.
Ultrastable Lead‐Free Double Perovskite Photodetectors with Imaging Capability
Authors: Li Ying , Shi Zhifeng , Lei Lingzhi , Li Sen , Yang Dongwen , Wu Di , Xu Tingting , Tian Yongzhi , Lu Yingjie , Wang Ye , Zhang Lijun , Li Xinjian , Zhang Yuantao , Du Guotong , Shan Chongxin
Published: March 2019

Recently, the halide perovskites have increasingly received attention because of their superior capabilities in photodetector applications. However, the well‐known instability and lead‐toxicity are two major obstacles for their commercialization and practical applications. In this work, self‐powered photodetectors based on solution‐processed double perovskite Cs2AgBiBr6 films are fabricated for the first time. Owing to the high material integrity of Cs2AgBiBr6 and efficient interfacial charge transfer from perovskite to the underlying electron‐quenching layer, the photodetector demonstrates excellent performances. Especially, the unencapsulated device demonstrates a good working stability in the open air. Typically it has the ability to endure a high temperature of 373 K for 10 h continuous running, demonstrating a good temperature resistance. In addition, after 3‐month storage in open air, the photodetection capability of the device can almost be maintained. By deploying the photodetector as a point‐like sensing pixel, high‐resolution imaging patterns are acquired, which is the first report on imaging applications of lead‐free perovskite photodetectors. The obtained results suggest that the lead‐free double perovskite Cs2AgBiBr6 is potentially an attractive candidate to be applied in high‐efficiency and stable photodetectors that can be employed in optical imaging.
Hyperporous Carbon from Triptycene‐Based Hypercrosslinked Polymer for Iodine Capture
Authors: Zhang Qing‐Mei , Zhai Tian‐Long , Wang Zhen , Cheng Guang , Ma Hui , Zhang Qing‐Pu , Zhao Yu‐Hang , Tan Bien , Zhang Chun
Published: March 2019

Considering the nuclear fuel reprocessing conditions at 75 °C and the oxidizability of iodine, thermal and chemical stabilities are especially important for porous materials to enrich iodine. However, most organic or metal coordinated porous materials hardly meet this long‐term demand. Here, highly porous carbon is prepared from pyrolysis at high temperature using triptycene‐based hypercrosslinked polymer as precursor, and possesses high Brunauer–Emmett–Teller (BET) surface area of 3125 m2 g−1 and pore volume of 1.60 cm3 g−1, and exhibits excellent iodine uptake ability of 340 wt% at 75 °C. Moreover, the obtained hyperporous carbon also displays remarkable capture efficiency of iodine from water with the maximum adsorption capacity of 926 mg g−1. With the characteristics of easy preparation and good chemical and thermal stabilities, the hyperporous carbon may be an ideal adsorbent in iodine capture.
Black Phosphorous/Indium Selenide Photoconductive Detector for Visible and Near‐Infrared Light with High Sensitivity
Authors: Cao Rui , Wang Hui‐De , Guo Zhi‐Nan , Sang David K. , Zhang Li‐Yuan , Xiao Quan‐Lan , Zhang Yu‐Peng , Fan Dian‐Yuan , Li Jian‐Qing , Zhang Han
Published: March 2019

2D materials offer tremendous opportunities for designing and investigating multifunctional high‐performance electronic and optoelectronic devices. In this contribution, a photogate vertical structure is devised by vertically stacking layered indium selenide (InSe) on top of layered black phosphorous (BP). The photodetector built with the vertical structure possesses a wide response range from 405 to 1550 nm, and the photodetector exhibits a relatively fast (≈22 ms) response and high responsivity of ≈53.80 A W−1 at λ = 655 nm and 43.11 A W−1 at λ = 1550 nm, respectively. Under visible‐light illumination (λ = 655 nm), the external quantum efficiency of the device can reach 1020%. By taking advantage of gate‐tunable modulation, the forward‐to‐reverse bias current ratio is as high as 103. In addition, the environmental degradation of BP could be effectively suppressed by InSe capping. The high sensitivity, broad spectral response, and enhanced stability of the photodetector show that the photogate structure provides a new opportunity for broad spectral detection or imaging at room temperature by using 2D materials with a vertical structure.
A Recyclable Chiral 2‐(Triphenylmethyl)pyrrolidine Organocatalyst Anchored to [60]Fullerene
Authors: Rosso Cristian , Emma Marco G. , Martinelli Ada , Lombardo Marco , Quintavalla Arianna , Trombini Claudio , Syrgiannis Zois , Prato Maurizio
Published: March 2019

Hybridization of a chiral 3‐hydroxy‐2‐trityl‐pyrrolidine deriving from (R)‐pyrrolidinol with [60]fullerene via click chemistry provides a highly efficient supported enantioselective organocatalyst, which was successfully exploited in a Michael addition of malonates to cinnamaldehydes, via iminium ion activation. The supported organocatalyst was recycled up to six times, with only a moderate decrease in terms of activity and with no loss in enantioselectivity.

magnified image
Artificial Neural Network (ANN) to Spiking Neural Network (SNN) Converters Based on Diffusive Memristors
Authors: Midya Rivu , Wang Zhongrui , Asapu Shiva , Joshi Saumil , Li Yunning , Zhuo Ye , Song Wenhao , Jiang Hao , Upadhay Navnidhi , Rao Mingyi , Lin Peng , Li Can , Xia Qiangfei , Yang J. Joshua
Published: March 2019

Biorealistic spiking neural networks (SNN) are believed to hold promise for further energy improvement over artificial neural networks (ANNs). However, it is difficult to implement SNNs in hardware, in particular the complicated algorithms that ANNs can handle with ease. Thus, it is natural to look for a middle path by combining the advantages of these two types of networks and consolidating them using an ANN–SNN converter. A proof‐of‐concept study of this idea is performed by experimentally demonstrating such a converter using diffusive memristor neurons coupled with a 32×1 1‐transistor 1‐memristor (1T1R) synapse array of drift memristors. It is experimentally verified that the weighted sum output of the memristor synapse array can be readily converted into the frequency of oscillation of an oscillatory neuron based on a SiOxNy:Ag diffusive memristor. Two converters are then connected capacitively to demonstrate the synchronization capability of this network. The compact oscillatory neuron comprises multiple transistors and has much better scalability than a complimentary metal oxide semiconductor (CMOS) integrate and fire neuron. It paves the way for emulating half center oscillators in central pattern generators of the central nervous system.
A Synthetic, Transiently Thermoresponsive Homopolymer with UCST Behaviour within a Physiologically Relevant Window
Authors: Zhang Zhiyue , Li Hui , Kasmi Sabah , Van Herck Simon , Deswarte Kim , Lambrecht Bart N. , Hoogenboom Richard , Nuhn Lutz , De Geest Bruno G.
Published: March 2019

Interactive materials that can respond to a trigger by changing their morphology, but that can also gradually degrade into a fully soluble state, are attractive building blocks for the next generation of biomaterials. Herein, we design such transiently responsive polymers that exhibit UCST behaviour while gradually losing this property in response to a hydrolysis reaction in the polymer side chains. The polymers operate within a physiologically relevant window in terms of temperature, pH, and ionic strength. Whereas such behaviour has been reported earlier for LCST systems, it is at present unexplored for UCST polymers. Furthermore, we demonstrate that, in contrast to LCST polymers, in aqueous medium the UCST polymer forms a coacervate phase below the UCST, which can entrap a hydrophilic model protein, as well as a hydrophobic dye. Because of their non‐toxicity, we also provide in vivo proof of concept of the use of this coacervate as a protein depot, in view of sustained‐release applications.
SCOTfluors: Small, Conjugatable, Orthogonal, and Tunable Fluorophores for In Vivo Imaging of Cell Metabolism
Authors: Benson Sam , Fernandez Antonio , Barth Nicole D. , de Moliner Fabio , Horrocks Mathew H. , Herrington C. Simon , Abad Jose Luis , Delgado Antonio , Kelly Lisa , Chang Ziyuan , Feng Yi , Nishiura Miyako , Hori Yuichiro , Kikuchi Kazuya , Vendrell Marc
Published: March 2019

The transport and trafficking of metabolites are critical for the correct functioning of live cells. However, in situ metabolic imaging studies are hampered by the lack of fluorescent chemical structures that allow direct monitoring of small metabolites under physiological conditions with high spatial and temporal resolution. Herein, we describe SCOTfluors as novel small‐sized multi‐colored fluorophores for real‐time tracking of essential metabolites in live cells and in vivo and for the acquisition of metabolic profiles from human cancer cells of variable origin.
Green electrospun nanocuprous oxide–poly(ethylene oxide)–silk fibroin composite nanofibrous scaffolds for antibacterial dressings
Authors: Zheng Zexin , Zhang Kuihua , Wu Bo , Yang Haoyi , Wang Mengqi , Dong Tianhong , Zhang Jiaying , He Ying
Published: March 2019

Cuprous oxide (Cu2O) nanoparticles have attracted extensive attention because of their excellent optical, catalytic, antibacterial, and antifungal properties and low cost. Nano‐Cu2O–poly(ethylene oxide) (PEO)–silk fibroin (SF) composite nanofibrous scaffolds (CNSs) were fabricated through green electrospinning to impart excellent antibacterial properties onto nanofibrous scaffolds. Scanning electron microscopy revealed that the nanofibers became more nonuniform and appeared more and more as beads in the nanofibers with increasing nano‐Cu2O concentration, and no obvious morphological changes were observed after 75% EtOH vapor treatment. Transmission electron microscopy and X‐ray photoelectron spectroscopy demonstrated that nano‐cuprous oxide (nano‐Cu2O) was successfully loaded into the PEO–SF nanofibers. Fourier transform infrared–attenuated total reflectance spectroscopy results indicate that nano‐Cu2O did not induce SF conformation from random coils to β sheets. The SF conformation converted from random coils to β sheets after 75% EtOH vapor treatment. The results of water contact angle testing and swelling property measurement clarified that nano‐Cu2O–PEO–SF CNSs possessed outstanding hydrophilicity. Nano‐Cu2O–PEO–SF CNSs exhibited better antibacterial activity against both Gram‐negativeEscherichia coliand Gram‐positiveStaphylococcus aureusbacteria than PEO–SF nanofibrous scaffolds, and the antibacterial activity increased with increasing nano‐Cu2O concentration. Cell viability studies with pig iliac endothelial cells demonstrated that nano‐Cu2O–PEO–SF CNSs had no cytotoxicity. Nano‐Cu2O–PEO–SF CNSs are expected to be ideal biomimetic antibacterial dressings for wound healing. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47730.
Effects of an Educational Film About Body Donors on Students' Empathy and Anxiety Levels in Gross Anatomy
Authors: Iaconisi Julia , Hasselblatt Friederike , Mayer Benjamin , Schoen Michael , Böckers Tobias Maria , Böckers Anja
Published: March 2019

While most German anatomy institutes provide only limited information about body donors and their lives, students have expressed a desire to learn more about these individuals, especially about their motivations to donate their bodies for the sake of medical education. In order to gratify this wish, as well as to further humanize body donors, an educational film was compiled, and a study designed to capture the film's effects on medical students. This is the first study using standardized, validated psychological tools to evaluate the impact of an educational film about body donors on students’ empathy and psychological stress levels. The study followed a longitudinal, controlled, and cluster randomized design, including 77 (48 females/29 males) participants who watched the video either before, midway, or after the dissection course. Questionnaires were completed at four points in time applying the Jefferson Scale for Empathy (JSPE‐S) and the Interpersonal Reactivity Index (IRI) to measure empathy. Psychological stress levels were recorded by the Brief Symptom Inventory (BSI). Overall, students recommended the film to be shown to all students (median 6.0; maximum on the six‐point Likert scale). Viewing the film revealed no significant changes between study groups or over time in JSPE‐S sum scores. All groups demonstrated a significant reduction of BSI values before the dissection course actually started and increased values during the course, but both developments appeared not to be associated with the intervention. Overall, the educational film did not correlate with any negative effects on students’ empathy and psychological stress levels, and it was strongly approved of by students, as it provided more humanizing personal information about body donors without violating their anonymity.
Bioinspired Actuators Based on Stimuli‐Responsive Polymers
Authors: Cui Huanqing , Zhao Qilong , Wang Yunlong , Du Xuemin
Published: March 2019

Organisms exhibit strong environmental adaptability by controllably adjusting their morphologies or fast locomotion; thus providing constant inspiration for scientists to develop artificial actuators that not only have diverse and sophisticated shape‐morphing capabilities, but can also further transfer dynamic and reversible shape deformations into macroscopic motion under the following principles: asymmetric friction, the Marangoni effect, and counteracting forces of the surrounding conditions. Among numerous available materials for fabricating bioinspired artificial actuators, stimuli‐responsive polymers are superior in their flexible features and the ability to change their physicochemical properties dynamically under external stimuli, such as temperature, pH, light, and ionic strength. Herein, different mechanisms, working principles, and applications of stimuli‐responsive polymeric actuators are comprehensively introduced. Furthermore, perspectives on existing challenges and future directions of this field are provided.
Baubetriebliche Untersuchung von Robotersystemen im Mauerwerksbau
Authors: Malkwitz Alexander , Spengler Arnim J. , Bruckmann Tobias
Published: March 2019

Die Bedeutung von Robotersystemen in der Bauwerkserstellung wird künftig stetig zunehmen. Das zeigt sich u. a. an den zunehmenden Pressemeldungen über erfolgreiche Bauvorhaben und der steigenden Anzahl an verfügbaren Systemen. In diesem Artikel wird untersucht, wo die spezifischen Stärken und Schwächen einzelner Robotersysteme liegen. An der Universität Duisburg‐Essen wird derzeit am Einsatz von Seilrobotern im Mauerwerksbau geforscht. Der vorliegende Artikel präsentiert erste Ergebnisse der Versuchsreihen am Seilroboter. Grundlage bilden die gewonnenen Erkenntnisse sowie die Auswertung vorhandener Literatur und die Sichtung von aktuellem Videomaterial. Ein Ergebnis ist, dass jedes Robotersystem spezifische Stärken und Schwächen aufweist und der Seilroboter gut im Mauerwerksbau eingesetzt werden kann. Es zeigt sich, dass die Kombination und Parallelfertigung mit verschiedenen Robotersystemen langfristig die gefundenen Schwächen einzelner Systeme ausgleichen kann.
CAD‐integrierte Analyse im Entwurfsprozess
Authors: Oberbichler Thomas , Bauer Anna M. , Goldbach Ann‐Kathrin , Wüchner Roland , Bletzinger Kai‐Uwe
Published: March 2019

Leichtbau ist geprägt von seiner filigranen Tragstruktur, die sich durch eine Vielfalt von grazilen Formen und organisch wirkenden Freiformflächen auszeichnet. Moderne CAD‐Systeme nutzen NURBS (Non‐uniform rational B‐Splines), um die Formsprache des Leichtbaus dem Computer zugänglich zu machen.

Die isogeometrische B‐Rep‐Analyse (IBRA) verwendet NURBS für das Lösen strukturmechanischer Probleme. Durch die Nutzung der gleichen geometrischen und topologischen Beschreibungen wird der kontinuierliche Datenaustausch zwischen CAD‐ und Analyse‐Software vereinfacht.

Die einheitliche Modellbeschreibung begünstigt parametrische Entwurfsprozesse. Vorteile ergeben sich auch dort, wo die Ergebnisse einer Analyse wieder in das CAD übertragen werden sollen; beispielsweise bei einer Baufortschrittsmodellierung oder einer Formfindung, wenn es darum geht, die berechneten Geometrien erneut in den Entwurfsprozess einzubinden und mit ihnen weiterzuarbeiten. Im Hinblick auf biegeaktive Strukturen spielen die Glattheit der Modellgeometrie und die Abbildung ihrer Verformung eine bedeutende Rolle. Durch die Verwendung von NURBS ist dies gegeben.
Oil Palm Biomass Biorefinery for Sustainable Production of Renewable Materials
Authors: Hassan Mohd A. , Ahmad Farid Mohammed A. , Shirai Yoshihito , Ariffin Hidayah , Othman Mohd R. , Samsudin Mohd H. , Hasan Mohamad Y.
Published: March 2019

Oil palm biomass is widely known for its potential as a renewable resource for various value‐added products due to its lignocellulosic content and availability. Oil palm biomass biorefinery is an industry that comes with sociopolitical benefits through job opportunities, as well as potential environmental benefits. Many studies have been conducted on the technological advancements of oil‐palm biomass‐derived renewable materials, which are discussed comprehensively in this review. Recent technological developments have made it possible to bring new and innovative technologies to commercialization, such as compost, biocharcoal, biocomposites, and bioplastics.
Application of Imaging Flow Cytometry for the Characterization of Intracellular Attributes in Chinese Hamster Ovary Cell Lines at the Single‐Cell Level
Authors: Pekle Eva , Smith Andrew , Rosignoli Guglielmo , Sellick Christopher , Smales C. M. , Pearce Claire
Published: March 2019

Biopharmaceutical manufacturing using Chinese hamster ovary (CHO) cells requires the generation of high‐producing clonal cell lines. During cell line development, cell cloning using fluorescence‐activated cell sorting (FACS) has the potential to combine isolation of single cells with sorting based on specific cellular attributes that correlate with productivity and/or growth, identifying cell lines with desirable phenotypes for manufacturing. This study describes the application of imaging flow cytometry (IFC) to characterize recombinant cell lines at the single‐cell level to identify cell attributes predictive of productivity. IFC assays are developed to quantify the organelle content and recombinant heavy‐chain (HC) and light‐chain (LC) polypeptide as well as messenger RNA (mRNA) amounts in single cells. The assays are then validated against orthogonal standard flow cytometry, western blot, and quantitative reverse transcription polymerase chain reaction (qRT‐PCR) methods. The authors describe how these IFC assays may be used in cell line development and show how cellular properties can be correlated with productivity at the single‐cell level, allowing the isolation of such cells during the cloning process. From the analysis, HC polypeptide and mRNA are found to be predictive of productivity early in the culture; however, specific organelle content did not show any correlation with productivity.
Engineering of Phosphoserine Aminotransferase Increases the Conversion of l‐Homoserine to 4‐Hydroxy‐2‐ketobutyrate in a Glycerol‐Independent Pathway of 1,3‐Propanediol Production from Glucose
Authors: Zhang Yujun , Ma Chengwei , Dischert Wanda , Soucaille Philippe , Zeng An‐Ping
Published: March 2019

Phosphoserine aminotransferase (SerC) from Escherichia coli (E. coli) MG1655 is engineered to catalyze the deamination of homoserine to 4‐hydroxy‐2‐ketobutyrate, a key reaction in producing 1,3‐propanediol (1,3‐PDO) from glucose in a novel glycerol‐independent metabolic pathway. To this end, a computation‐based rational approach is used to change the substrate specificity of SerC from l‐phosphoserine to l‐homoserine. In this approach, molecular dynamics simulations and virtual screening are combined to predict mutation sites. The enzyme activity of the best mutant, SerCR42W/R77W, is successfully improved by 4.2‐fold in comparison to the wild type when l‐homoserine is used as the substrate, while its activity toward the natural substrate l‐phosphoserine is completely deactivated. To validate the effects of the mutant on 1,3‐PDO production, the “homoserine to 1,3‐PDO” pathway is constructed in E. coli by coexpression of SerCR42W/R77W with pyruvate decarboxylase and alcohol dehydrogenase. The resulting mutant strain achieves the production of 3.03 g L−1 1,3‐PDO in fed‐batch fermentation, which is 13‐fold higher than the wild‐type strain and represents an important step forward to realize the promise of the glycerol‐independent synthetic pathway for 1,3‐PDO production from glucose.
Clinical approach to the knotting diagnostic quadripolar catheter during zero‐fluoro electrophysiological study
Authors: Tan Vern Hsen , Ching Chi Keong , Wong Kelvin Cheok Keng
Published: March 2019

Key Clinical Message

We report a case of electrophysiology catheter knotting when inserted without fluoroscopic guidance followed by technique to unravel the knot via ipsilateral femoral vein. We advocate caution when manipulating catheters using minimal/zero fluoroscopic technique and having a low threshold to screen under fluoroscopy when encountering difficulties during catheter insertion.
Functional Applications of Metallic Glasses in Electrocatalysis
Authors: Hu Yuan‐Chao , Sun Chenxiang , Sun Chunwen
Published: March 2019

Metallic glasses (MGs), which are also known as amorphous metals, are formed by quenching the melts at a super high cooling rate (e. g. 106 K/s) to avoid crystallization. Compared with ordinary metals, there is no long‐range translational order and crystalline defects in MGs. Benefitting from this unique structural characteristic, MGs show many superior mechanical, physical and chemical properties and thus have been attracting intensive attentions in applications as structural materials. The investigations on the functional properties of MGs are still at the early stage, but immense potential in electrochemically functional applications has been demonstrated in recent years. In this Minireview, we aim to present an overview of the functional properties of this class of novel metallic glassy catalysts and some achievements obtained so far. We mainly focus on the applications of MGs in various electrochemical applications, like hydrogen evolution reaction and oxygen evolution reaction as well as fuel cells. The strategies for optimizing the performance of these amorphous catalysts are discussed as well, including high‐throughput screening and nano‐engineering. In the absence of crystalline ordering, the atomic‐scale structural mechanism of MGs in electrocatalysis may be unique and will be explored. Finally, we also give perspectives on how to design novel and superior electrocatalysts for future electrocatalysis applications.
Identification of an Oxalamide Ligand for Copper‐Catalyzed C−O Couplings from a Pharmaceutical Compound Library
Authors: Chan Vincent S. , Krabbe Scott W. , Li Changfeng , Sun Lijie , Liu Yue , Nett Alex J.
Published: March 2019

A typical pharmaceutical compound library is stocked with molecular diversity and could provide a platform for the discovery of new ligand structures. Herein, we describe the use of this approach in combination with high throughput screening to identify N,N’‐bis(thiophene‐2‐ylmethyl)oxalamide as a ligand that is generally effective for copper‐catalyzed C−O cross‐couplings to prepare both biarylethers as well as phenols under mild conditions.
Preparation of Titanocene–Gold Compounds Based on Highly Active Gold(I)‐N‐Heterocyclic Carbene Anticancer Agents: Preliminary in vitro Studies in Renal and Prostate Cancer Cell Lines
Authors: Curado Natalia , Giménez Nora , Miachin Kirill , Aliaga‐Lavrijsen Mélanie , Cornejo Mike A. , Jarzecki Andrzej A. , Contel María
Published: March 2019

Heterometallic titanocene‐based compounds containing gold(I)‐phosphane fragments have been extremely successful against renal cancer in vitro and in vivo. The exchange of phosphane by N‐heterocyclic carbene ligands to improve or modulate their pharmacological profile afforded bimetallic complexes effective against prostate cancer, but less effective against renal cancer in vitro. Herein we report the synthesis of new bimetallic Ti–Au compounds by the incorporation of two previously reported highly active gold(I)‐N‐heterocyclic carbene fragments derived from 4,5‐diarylimidazoles. The two new compounds [(η5‐C5H5)2TiMe(μ‐mba)Au(NHC)] (where NHC=1,3‐dibenzyl‐4,5‐diphenylimidazol‐2‐ylidene, NHC‐Bn 2 a; or 1,3‐diethyl‐4,5‐diphenylimidazol‐2‐ylidene, NHC‐Et 2 b) with the dual linker (‐OC(O)‐p‐C6H4‐S‐) containing both a carboxylate and a thiolate group were evaluated in vitro against renal and prostate cancer cell lines. The compounds were found to be more cytotoxic than previously described Ti–Au compounds containing non‐optimized gold(I)‐N‐heterocyclic fragments. We present studies to evaluate their effects on cell death pathways, migration, inhibition of thioredoxin reductase (TrxR) and vascular endothelial growth factor (VEGF) in the PC3 prostate cancer cell line. The results show that the incorporation of a second metallic fragment such as titanocene into biologically active gold(I) compounds improves their pharmacological profile.
Toward the Characterization of DAPT Interactions with γ‐Secretase
Authors: Aguayo‐Ortiz Rodrigo , Guzmán‐Ocampo Dulce C. , Dominguez Laura
Published: March 2019

DAPT is a potent γ‐secretase (GS) inhibitor that blocks the production of short amyloid‐β (Aβ) peptides. Aggregation and oligomerization of Aβ peptides have been associated with the development and progression of Alzheimer's disease. A recent cryo‐electron microscopy density map disclosed DAPT binding at the GS active site. In this study, we employed the density map data to assign a possible binding pose of DAPT to characterize its dynamic behavior through different molecular dynamics simulation approaches. Our simulations showed a high preference of DAPT for the intramembrane region of the protein and that its entry site is located between TM2 and TM3 of PS1. DAPT interaction with the active site led to a decreased flexibility of key PS1 regions related to the recognition and internalization of GS substrates. Moreover, our study showed that the proximity of DAPT to the catalytic aspartic acids should be able to modify its protonation states, preventing the enzyme from reaching its active form. These results provide valuable information toward understanding the molecular mechanism of a GS inhibitor for the development of novel Alzheimer's disease treatments.
Design of Colloidally Stable and Non‐Toxic Petox‐Based Polymersomes for Cargo Molecule Encapsulation
Authors: Oz Umut Can , Kucukturkmen Berrin , Ozkose Umut Ugur , Gulyuz Sevgi , Bolat Zeynep Busra , Telci Dilek , Sahin Fikrettin , Yilmaz Ozgur , Bozkir Asuman
Published: March 2019

Polymersomes are vesicular constructs formed by the self‐assembly of polymer amphiphiles. Here we report the fabrication of PEtOx‐b‐PLA polymersomes at physiological pH/salt concentration and the determination of a fPEtOx range, which is one of the most recognized factors that governs the self‐assembly of amphiphilic copolymers, for the first time. The findings indicate that PEtOx‐b‐PLA copolymers, containing PEtOx fractions of varied lengths, self‐assemble to form polymersomes in the range of 98.35 to 119.50 nm. The encapsulation potential of PEtOx‐b‐PLA polymersomes was demonstrated by loading of docetaxel (hydrophobic) with 17.90% encapsulation efficiency and by loading of pDNA (hydrophilic) with 65.03% encapsulation efficiency. In addition, size distribution profiles showed that polymersomes are colloidally stable for 24 h at 37 °C and for 3 months at +4 °C. The cell viability results showed that PEtOx‐b‐PLA copolymer and polymersomes are not cytotoxic to HUVEC, HEK293 and hMSC cell lines.
Enhanced Charge Transport via Metallic 1T Phase Transition Metal Dichalcogenides‐Mediated Hole Transport Layer Engineering for Perovskite Solar Cells
Authors: Choi Yunseong , Jung Seungon , Oh Nam Khen , Lee Junghyun , Seo Jihyung , Kim Ungsoo , Koo Donghwan , Park Hyesung
Published: March 2019

In perovskite photovoltaic cells having a p‐i‐n structure, the hole transport layer (HTL) plays an important role in device performance because it has a direct impact on the crystallinity of overlying perovskite films as well as the interfacial charge transport. Poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT : PSS) has been widely used as an HTL owing to its desirable electrical and optical properties with solution processability. However, improving the functionality of PEDOT : PSS still requires broad attention to maximize the related solar cell performance, such as further enhancing the electrical properties to achieve better charge transport at the electrode and photoactive layer interface and reducing the nucleation energy barrier to improve crystallinity of the overlying perovskite films. Two‐dimensional transition metal dichalcogenides (TMDs) have been studied in various optoelectronic devices owing to their intriguing optoelectric features. In this study, tungsten diselenide (WSe2) was implemented with PEDOT : PSS to enhance the performance in p‐i‐n perovskite solar cells. The incorporation of WSe2 into PEDOT : PSS led to improved charge transport at the photoactive layer and electrode interface as well as the favorable growth of the perovskite crystal. As a result, a notable improvement in the performance of the solar cell having the WSe2‐mediated PEDOT : PSS HTL was observed in comparison to that of the PEDOT : PSS only device, which had power conversion efficiencies of 16.3% and 13.8%, respectively. The facile approach proposed in this study may be readily extended to various other perovskite‐based optoelectronic devices beyond solar cells toward the enhancement of device functionality.
Photocatalytic Selective Ring Hydrogenation of Phenol to Cyclohexanone over a Palladium‐Loaded Titanium(IV) Oxide under Hydrogen‐Free Conditions
Authors: Kinoshita Atsufumi , Nakanishi Kousuke , Tanaka Atsuhiro , Hashimoto Keiji , Kominami Hiroshi
Published: March 2019

Photocatalytic ring hydrogenation of phenol proceeded in an aqueous suspension of palladium‐loaded TiO2 at room temperature in the presence of oxalic acid as a hole scavenger, and cyclohexanone was produced in a high yield (90 %) without the use of hydrogen gas. Cyclohexanone was formed via keto‐enol tautomerism of cyclohexenol. The effects of hole scavengers and solvents on the hydrogenation of phenol can be explained by the adsorption behaviour of phenol and hole scavengers in the solvents. Over a Pd‐TiO2 photocatalyst, the apparent activation energy (Ea) in the ring hydrogenation of phenol and the Ea value in the hydrogenation of cyclohexanone were estimated to be 25 kJ mol−1 and 36 kJ mol−1, respectively, as calculated by using the Arrhenius equation. We concluded that the difference in the Ea values is attributable to the selective production of cyclohexanone and the decreased production of cyclohexanol in the ring hydrogenation of phenol over a Pd‐TiO2 photocatalyst.
Coexistence and competitive exclusion in mutualism
Authors: Johnson Christopher A. , Bronstein Judith L.
Published: March 2019

The competitive exclusion principle is fundamental to understanding coexistence. Well‐established theories predict the conditions for coexistence in consumer–resource interactions. Given that species often compete for commodities offered by mutualists, competitive exclusion theory should also be critical to understanding how mutualisms function. We explicitly apply the competitive exclusion principle to mutualism and derive a rule analogous to Tilman's R* rule for exploitative competition. Coexistence is impossible when competitors compete solely for a shared partner‐provided commodity because superior competitors deplete that commodity sufficiently to exclude inferior competitors. We then investigate how competition between two guild members for a partner‐provided commodity and a resource external to the mutualism affects competitor coexistence. There are three key results. First, coexistence is possible via partitioning of a partner‐provided commodity and another resource. Second, unlike in classic R* Theory, competitive outcomes are influenced both by species’ abilities to obtain commodities and their mutualisms with the shared commodity‐providing partner, which can indirectly alleviate competitors’ commodity limitation. Third, the outcome of competition has important consequences for the commodity‐providing partner, which depend on the type of mutualism and the competitive abilities of competing mutualists. This theory provides a novel framework for investigating how competitors for mutualistic commodities coexist in nature.
Exercise training in patients with a left ventricular assist device (Ex‐VAD): rationale and design of a multicentre, prospective, assessor‐blinded, randomized, controlled trial
Authors: Bobenko Anna , Schoenrath Felix , Knierim Jan H. , Friede Tim , Verheyen Nicolas , Mehra Mandeep R. , Haykowsky Mark , Herrmann‐Lingen Christoph , Duvinage André , Pieske‐Kraigher Elisabeth , Halle Martin , Falk Volkmar , Pieske Burkert , Edelmann Frank
Published: March 2019

Aims

Left ventricular assist device (LVAD) therapy is a promising option for patients with advanced heart failure (HF), refractory to guideline‐mandated medical treatment either as a bridge to heart transplantation or as lifelong therapy. Functional capacity improves after LVAD implantation but remains reduced in patients with long‐term LVAD therapy. Exercise training (ET) improves functional capacity and quality of life (QoL) in HF and may provide incremental benefits in patients supported with LVAD therapy.

Methods

The primary objective of Ex‐VAD is to investigate whether a 12‐week supervised ET can improve peak oxygen uptake (peakVO2) measured by cardiopulmonary exercise testing (CPET) on an ergometer. The study is powered to demonstrate a group difference of 3 mL/min/kg in peakVO2 at week 12, with a power of 0.9 and a standard deviation of 5 mL/min/kg. After baseline assessments to determine whether ET is safe, 66 patients at six trial sites with advanced HF and LVAD therapy will be randomized 2:1 to supervised ET or to the control arm of usual care alone. Patients randomized to ET will perform supervised aerobic endurance and resistance ET (three times/week) for 12 weeks. At baseline and during follow‐up, anthropometry, CPET, echocardiography (at rest and exercise), and QoL evaluation will be performed. Blood samples will be collected to examine cardiac‐specific relevant biomarkers. Overall physical activity, training sessions, and adherence will be monitored and documented throughout the study using accelerometers and patient diaries.

Conclusions

The Ex‐VAD trial will assess the effects of a supervised ET programme on peakVO2 and QoL in patients with LVAD. As LVAD therapy moves from crisis support to ambulatory functional enhancement, this trial will provide a rationale to improve functional capacity and, in perspective, cardiovascular outcomes in LVAD‐supported patients with advanced HF.
Ultrasound‐Assisted Formation of {Fe6Ln/Y4} Wheel‐Shaped Clusters and Condensed {Fe4Ln/Y2} Aggregates
Authors: Botezat Olga , van Leusen Jan , Kögerler Paul , Baca Svetlana G.
Published: March 2019

Two families of charge‐neutral heterometallic Fe‐4f coordination compounds comprising isobutyrate and amino alcoholate linkers were found to form exclusively upon ultrasonication irradiation. Under one‐pot conditions, the trinuclear precursor [Fe3O(O2CCHMe2)6(H2O)3](NO3)·2(MeCN)·2(H2O) reacts with Ln(NO3)3·xH2O or Y(NO3)3·6H2O, N‐butyldiethanolamine (bdeaH2) and NaN3 in methanol to yield the decanuclear clusters [Fe6M4(O2CCHMe2)8(N3)2(bdea)10]·n(solvent) (MIII = Y (1a·3MeOH), Gd (2a·2.5MeOH), Dy (3a·3.5MeOH·0.5H2O), Tb (4a·2MeOH), Ho (5a·2MeOH), as well as subsequently the hexanuclear compounds [Fe4M2(OH)2(O2CCHMe2)6(N3)2(bdea)4]·2(solvent) (MIII = Y (1b·2MeOH), Gd (2b·2MeOH), Dy (3b·2MeOH, 3c·2EtOH), Tb (4b·2MeOH), Er (6b·2MeOH), Tm (7b·2MeOH)). The {Fe6M4} clusters feature a wheel‐shaped architecture with the metal ions, interlinked by carboxylate and polyalcoholamine bridges, forming a saddle‐like ring. The hexanuclear {Fe4M2} clusters comprise two {Fe2M} triangles, connected via two bridging µ3‐OH– groups, which form a condensed core of metals additionally linked by deprotonated tripodal bdeaH2 ligands and bridging carboxylates. Magnetic measurements revealed predominant strong antiferromagnetic interactions within compounds 1–7 and out‐of‐phase signals for {Fe6Dy4} (3a·3.5MeOH·0.5H2O), {Fe6Tb4} (4a·2MeOH), and {Fe4Dy2} (3b·2MeOH).
Mercury Concentrations Vary Within and Among Individual Bird Feathers: A Critical Evaluation and Guidelines for Feather Use in Mercury Monitoring Programs
Authors: Peterson Sarah H. , Ackerman Joshua T. , Toney Matthew , Herzog Mark P.
Published: March 2019

Feathers are widely used to represent mercury contamination in birds. Yet, few recommendations exist that provide guidance for using bird feathers in mercury monitoring programs. We conducted a literature review and 5 experiments to show that mercury concentrations vary substantially within (vane >100% higher than calamus) and among (>1000%) individual feathers from the same bird. We developed a research tool and guidelines for using bird feathers for mercury studies based on 3 components: 1) variability of feather mercury concentrations within an individual bird (coefficient of variation), 2) desired accuracy of the measured mercury concentration, and 3) feather and bird mass. Our results suggest a general rule that if the goal is to limit analytical and processing costs by using whole feathers in only one sample boat, then to achieve an accuracy within 10% of a bird's overall average feather mercury concentration a bird with a coefficient of variation ≤10% must be <190 g (size of a large shorebird). To achieve an accuracy within 20%, a bird with a coefficient of variation ≤10% must be <920 g (a large duck). When more than one sample boat is needed to fit the required number of feathers to achieve the desired accuracy, the results suggest homogenizing feathers and analyzing an aliquot of ≥20 mg for mercury. The present study suggests increasing the number of feathers typically used per bird to assess mercury concentrations. Environ Toxicol Chem 2019;38:1164–1187. Published 2019 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Abstract

Feather mercury variability within a bird.