bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photopharmacological Control of Cyclic Antimicrobial Peptides
Authors: Yeoh Yuan Qi , Yu Jingxian , Polyak Steven W. , Horsley John R. , Abell Andrew D. 
Published: October 2018

AbstractGramicidin S is a naturally occurring antimicrobial cyclic peptide. Herein, we present a series of cyclic peptides based on gramicidin S that contain an azobenzene photoswitch to reversibly control secondary structure and, hence, antimicrobial activity. 1H NMR spectroscopy and density functional theory calculations revealed a β‐sheet/β‐turn secondary structure for the cis configuration of each peptide, and an ill‐defined conformation for all associated trans structures. The cis‐enriched and trans‐enriched photostationary states (PSSs) for peptides 1–3 were assayed against Staphylococcus aureus to reveal a clear relationship between well‐defined secondary structure, amphiphilicity and optimal antimicrobial activity. Most notably, peptides 2 a and 2 b exhibited a fourfold difference in antimicrobial activity in the cis‐enriched PSS over the trans‐enriched equivalent. This photopharmacological approach allows antimicrobial activity to be regulated through photochemical control of the azobenzene photoswitch, thereby opening new avenues in the design and synthesis of future antibiotics.
Electrical Adaptiveness and Electromechanical Response in Gel Composites of Carbon Nanomaterials
Authors: Park Chiyoung , Lee Seoung‐Ki 
Published: October 2018

AbstractMechanosensation is a critical life mechanism. Therefore, it has received much attention in recent years for diverse applications from wearable to biomedical devices. Recently, composite strain sensors composed of a polymer matrix and carbon nanomaterials have been extensively investigated using various processing methods, but mostly use elastic matrices. In general, the sensor sensitivity relies on the tunneling resistance or the ratio of the tunneling resistance to the total resistance of the sensor. In this minireview, we have described the working principles of strain sensors and the preparation of gel composites with carbon nanomaterials as conductive nanofillers. In particular, we emphasized the effects of viscoelastic polymer matrices in composite strain sensors, which have not been well investigated.
Probing the 3‐step Lithium Storage Mechanism in CH3NH3PbBr3 Perovskite Electrode by Operando‐XRD Analysis
Authors: Vicente Nuria , Bresser Dominic , Passerini Stefano , Garcia‐Belmonte Germà 
Published: October 2018

AbstractOrganic‐inorganic hybrid materials have gradually become one of the most actively studied research fields due to their fascinating properties. The reaction between lithium and organic‐inorganic halide perovskite has just recently been proposed. However, the exact mechanisms taking place in this electrode material have not been fully elucidated, yet. To shed light on these processes an operando‐X‐ray diffraction study has been performed and is reported herein. According to our results the lithiation of CH3NH3PbBr3 entails three reaction steps, distinguishable during the initial galvanostatic lithiation for different Li‐ion molar content x: (1) the initial Li+ insertion into the perovskite phase in which pure perovskite and lithiated phases coexist (0 <x<1), (2) the perovskite conversion reaction leading to the formation of metallic lead (1 <x<2), and finally, (3) the alloying of lithium with the metallic lead previously formed. In more detail, for x>0.3, the formation of a Lix:CH3NH3PbBr3 phase with distinctive X‐ray diffraction peaks is clearly detected, which coexists with the pristine material, till abruptly both phases disappear at x∼1 and CH3NH3Br and Pb metal are formed. It is shown that this conversion reaction is an irreversible process. The proposed mechanism for lithium storage gives a complete perspective of the complex structural environment involving the use of perovskite materials as electrodes for Li‐ion batteries.
Hierarchical Cobalt Sulfide/Molybdenum Sulfide Heterostructure as Bifunctional Electrocatalyst towards Overall Water Splitting
Authors: Shit Subhasis , Chhetri Suman , Bolar Saikat , Murmu Naresh C. , Jang Wooree , Koo Hyeyoung , Kuila Tapas 
Published: October 2018

AbstractThe development of non‐noble metal based electrocatalysts for overall water splitting is a potent strategy towards a carbon‐neutral and clean energy economy. Herein, hierarchical CoSx@MoS2 was synthesized via a one‐pot solvothermal process. Formation of the heterostructure was confirmed by electron microscopy and spectroscopic techniques. CoSx@MoS2 showed competent electrocatalytic activity towards both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline medium. Superior electrocatalytic activity was attributed to the increase in number of active sites, betterment in charge transfer and facilitation of H‐ and O‐ containing active species adsorption‐desorption at the active sites. Overall water splitting efficiency of CoSx@MoS2 was found to be superior in comparison to the state‐of‐the‐art RuO2‐Pt/C couple. Along with efficiency the heterostructure also exhibited long‐term operational durability. Thus, hierarchical CoSx@MoS2 is a potential non‐noble metal based bifunctional electrocatalyst towards overall water splitting.
Benzimidazolium‐ and Benzimidazolilydene‐Capped Cyclodextrins: New Perspectives in Anion Encapsulation and Gold‐Catalyzed Cycloisomerization of 1,6‐Enynes
Authors: Kaya Zeyneb , Andna Lucile , Matt Dominique , Bentouhami Embarek , Djukic Jean‐Pierre , Armspach Dominique 
Published: October 2018

AbstractA new way of introducing a N‐heterocyclic carbene cap onto cyclodextrins has been devised. The benzimidazolium intermediates were found to behave as receptors towards cavity matching anions. The corresponding C1‐ and C2‐symmetrical regioisomeric carbene gold(I) complexes have been tested in a benchmark asymmetric cycloisomerization of 1,6‐enynes. Up to 50 % ee was achieved for the enantioselective cycloisomerization of N‐allyl‐4‐methyl‐N‐(3‐phenylprop‐2‐yn‐1‐yl)benzenesulfonamide.
Highly Dynamic and Tunable Behavior of 1D Coordination Polymers Based on the Bispidine Ligand
Authors: Rossetti Arianna , Lippi Martina , Martí‐Rujas Javier , Sacchetti Alessandro , Cametti Massimo 
Published: October 2018

AbstractLigands L1 and L2 have been designed, synthesized, and used to build for the first time bispidine‐based coordination polymers (CPs) in combination with MnII. The novel CPs have been structurally characterized by single‐crystal (SC) and powder X‐ray diffraction (P‐XRD) techniques, showing that they are composed of 1D ribbon‐like chains that adopt various arrangements depending on the trapped solvent species. These materials show highly dynamic behavior as they undergo heterogeneous solid/liquid and solid/vapor multiple solvent exchange processes, comprising crystalline–amorphous–crystalline, selective adsorption and SC‐to‐SC transformations, where major structural reorganization of the 1D ribbons are observed. By tuning inter‐ribbon interactions through expansion of the ligand's accessible surface, the dynamic behavior can be effectively modulated.
Near‐Infrared Luminescent Ternary Ag3SbS3 Quantum Dots by in situ Conversion of Ag Nanocrystals with Sb(C9H19COOS)3
Authors: Di Qiumei , Wang Juwen , Zhao Zhengjing , Liu Jiajia , Xu Meng , Liu Jia , Rong Hongpan , Chen Wenxing , Zhang Jiatao 
Published: October 2018

AbstractDifferently from the normal three single precursor method to produce colloidal ternary quantum dots (QDs), herein ternary Ag3SbS3 quantum dots (QDs) with efficient near‐infrared (NIR) luminescence have been prepared by a new facile in situ conversion of Ag nanocrystals (NCs) with a binary Sb/S organic precursor Sb(C9H19COOS)3 under low temperature. The unprecedented construction evolution from Ag NCs to Ag3SbS3/Ag hetero‐structure and final monodisperse Ag3SbS3 QDs has been demonstrated. These novel Ag3SbS3 QDs exhibit efficient NIR emission at ≈1263 nm and possess high colloidal stability.
Covalent Grafting of BPin functions on Carbon Nanotubes and Chan–Lam–Evans Post‐Functionalization
Authors: Desmecht Antonin , Sheet Debobrata , Poleunis Claude , Hermans Sophie , Riant Olivier 
Published: October 2018

AbstractThe chemical functionalization of carbon nanotubes is often a prerequisite prior to their use in various applications. The covalent grafting of 4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane (BPin) functional groups directly on the surface of multi‐ and single‐walled carbon nanotubes, activated by nucleophilic addition of nBuLi, was carried out. Thermogravimetric analysis (TGA) coupled with mass spectrometry, Raman spectroscopy, X‐ray photoelectron spectroscopy (XPS) and time‐of‐flight secondary ions mass spectrometry (ToF‐SIMS) confirmed the efficiency of this methodology and proved the integrity and covalent grafting of the BPin functional groups. These groups were further reacted with various nucleophiles in the presence of a copper(II) source in the conditions of the aerobic Chan–Lam–Evans coupling. The resulting materials were characterized by TGA, XPS and ToF‐SIMS. This route is efficient, reliable and among the scarce reactions that enable the direct grafting of heteroatoms at carbonaceous material surfaces.
Troponin‐I levels as a potential prognostic biomarker of sacubitril/valsartan treatment response in heart failure with reduced ejection fraction: Who will benefit most?
Authors: Nakou Eleni S. , Marketou Maria E. , Chlouverakis Gregory I. , Patrianakos Alexandros P. , Vardas Panos E. , Parthenakis Fragiskos I. 
Published: October 2018

BackgroundDespite robust data on the benefits of sacubitril/valsartan (LCZ696) in patients with chronic heart failure with reduced ejection fraction (HFrEF), there is no evidence yet on prespecified predictive markers of its efficacy.
HypothesisThe objective of this study was to identify potential prognostic factors of LCZ696 treatment response.MethodsWe included 48 symptomatic patients with chronic HFrEF (left ventricular ejection fraction ≤35%) and New York Heart Association (NYHA) class II/III: Group A (N = 23) received LCZ696 (105 ± 30 mg twice daily), whereas it was not prescribed in group B (N = 25) according to physician's judgment. Analysis of biochemical parameters, cardiopulmonary exercise testing, and echocardiographic evaluation was performed at baseline and 6 months later.ResultsThe baseline serum troponin‐I levels (TnI) and peak oxygen uptake (VO2max) were positively associated with the increase in VO2max (ΔVO2max = +14.11%, P < 0.05 vs group B) after sacubitril/valsartan treatment (r = 0.68, P = 0.001 and r = 0.57, P = 0.004, respectively). Positive correlations were reported between ΔVO2max and the improvements in the ratio of early diastolic filling to myocardial tissue velocity (ΔE/E′) and the tricuspid annular peak systolic velocity (ΔSa) in group A (r = 0.58, P = 0.004 and r = 0.60, P = 0.002, respectively). In multiple regression analysis, ΔVO2max was correlated significantly with TnI (beta = 0.35, P = 0.048), ΔE/E′ (beta = 0.36, P = 0.031) and ΔSa (beta = 0.37, P = 0.035).ConclusionsTnI levels may be an independent predictive marker of sacubitril/valsartan efficacy in HFrEF.
An improved scheme for outsourced computation with attribute‐based encryption
Authors: Yang Haining , Sun Jiameng , Qin Jing , Ma Jixin 
Published: October 2018

SummaryWith the wide deployment of cloud computing, outsourcing complicated computational tasks to cloud service providers has attracted much attention. An increasing number of clients with computationally constrained devices choose to outsource their heavy tasks to cloud servers to reduce the computational overhead in local. However, how to preserve the integrity of computational results becomes a challenge since commercial cloud servers are not trusted. Public verifiability is an effective mechanism to allow clients to verify the integrity of the results returned by the servers. Because the results are sensitive in many applications, it raises the problem of privacy leakage in the public verification process. In this paper, we propose an efficient verifiable computation scheme while keeping output privacy. The proposed scheme achieves blind verifiability such that the verifiers who have not the additional information (retrieve key) can verify the integrity of the result without learning the result. Furthermore, by combining with (k,n)‐threshold sharing, our scheme allows the clients jointly learn the results.
Performance modeling of a geophysics application to accelerate over‐decomposition parameter tuning through simulation
Authors: Keller Tesser Rafael , Mello Schnorr Lucas , Legrand Arnaud , Heinrich Franz Christian , Dupros Fabrice , Navaux Philippe O.A. 
Published: October 2018

SummaryFinite‐difference methods are commonplace in High Performance Computing applications. Despite their apparent regularity, they often exhibit load imbalance that damages their efficiency. We characterize the spatial and temporal load imbalance of Ondes3D, a typical finite‐differences application dedicated to earthquake modeling. Our analysis reveals imbalance originating from the structure of the input data, and from low‐level CPU optimizations. Ondes3D was successfully ported to AMPI/CHARM++ using over‐decomposition and MPI process migration techniques to dynamically rebalance the load. However, this approach requires careful selection of the over‐decomposition level, the load balancing algorithm, and its activation frequency. These choices are usually tied to application structure and platform characteristics. In this article, we propose a workflow that leverages the capabilities of SimGrid to conduct such study at low experimental cost. We rely on a combination of emulation, simulation, and application modeling that requires minimal code modification and manages to capture both spatial and temporal load imbalance to faithfully predict the performance of dynamic load balancing. We evaluate the quality of our simulation by comparing simulation results with the outcome of real executions and demonstrate how this approach can be used to quickly find the optimal load balancing configuration for a given application/hardware configuration.
A novel discrete CURVELET transform and modified WHOG for video surveillance services
Authors: Epsiba P. , Kumaratharan N. , Suresh G. 
Published: October 2018

SummaryNowadays, with huge advent of mobile technology and surveillance supports there is increase in demand for visual quality rapidly. H.265/HEVC focuses on HDVC techniques with employing edge object detection‐based scheme. This paper proposes a novel discrete curvelet transform and modified WHOG for video surveillance services. The proposed discrete curvelet transform and modified WHOG‐based schemes were ensured optimal performance both in detection of edges and information coding. The decomposition of bit‐depth among two levels establishes the details of intensity components and Codec efficiency in all level. In addition, to improve the robustness of the proposed method in terms of compression/encoding efficiency, frame‐based statistical features were encountered to optimize the intensity level or depth‐map. The simulated results reveal the effectiveness of the projected algorithm in edge‐based video compression for surveillance services, which avoids edge blurring and retains perceptual quality while reconstruction with viable PSNR.
Transpiration in recovering mixed loblolly pine and oak stands following wildfire in the Lost Pines region of Texas
Authors: Cooper Caitlyn E. , Aparecido Luiza M.T. , Muir James P. , Morgan Cristine L.S. , Heilman James L. , Moore Georgianne W. 
Published: October 2018

AbstractDepending on severity, wildfire alters stand biomass, tree species distribution, and age, which may modify stand transpiration (Et) and the amount of water available to other parts of the hydrologic cycle. Our objective was to determine how wildfire severity affectedEtin mixed pine/oak (Pinus taedaL./Quercus stellataWangehn.,Quercus marilandicaMuenchh.) stands in the Lost Pines eco‐region (Bastrop, TX, USA). Transpiration was estimated for mature pines and oaks at unburned and moderately burned sites and oak resprouts and pine saplings at a severely burned plot. On average, mature pines had 36% greater sap flux rates (Js) than mature oaks in the unburned and moderately burned stands. Under low moisture stress, regenerating pines had greaterJsthan resprouting oaks, butJsquickly decreased as soil moisture declined. By contrast, mature pines were unaffected by dry periods. Pines contributed most toEtat the unburned and moderate stands. Conversely, oakEtdominated the severely burned stand, contributing over 95%. Transpiration was greatest at the moderately burned stand (2.02 mm day−1), followed by the unburned (1.44 mm day−1), and the severely burned stands (0.46 mm day−1). Despite greaterJsin resprouts and saplings, reductions in total sapwood area resulted in lower stand‐level dailyEtat the severe site. Although severe fire decreased stand transpiration through reductions in vegetation density, individual oak resprouts appear to thrive, undeterred by high vapour pressure deficit. Without pine planting, oaks will likely dominate severely burned stands that could result in shifts to local hydrology and microclimate.
Preparation of a Double‐step Modified Carbon Paste Electrode for Trace Quantification of Acyclovir Using TiO2 Nanoparticle and β‐Cyclodextrin
Authors: Karim‐Nezhad Ghasem , Khorablou Zeynab , Mehdikhani Shabnam 
Published: October 2018

AbstractIn this work we reported, a simple and reproducible double‐step modified carbon paste electrode (CPE) for recognition and designation of Acyclovir (ACV). In the first stage, for acquiring the structure of TiO2 NPs‐CPE, 5 % TiO2 nanoparticles (NPs) doped into the electrode tissue. In the second stage, β‐Cyclodextrin (β‐CD) anchored on the TiO2 NPs‐CPE surface by electropolymerization which yields a β‐CD/TiO2 NPs‐CPE. Topography, characteristics and electrochemical response of the fabricated electrodes with such techniques as: the field emission scanning electron microscopy (FESEM), chronocoulometry (CC), cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were analyzed. Also the spent TiO2 NPs powders were characterized by X‐ray diffraction (XRD). The results illustrated that this sensor designed efficiently increases the surface area of composite electrode and the performance of the oxidation of ACV at the surface modified electrode compared to the bare electrode improved. Under the desirable situations, the proposed of analytical procedure was proved to be applicable in two linear calibration ranges betwixt 0.09 to 2.98 and 2.98 to 47.61 μM. The detection limit was estimated for low concentrations ACV 21 nM (S/N=3). Eventually, the fabricated composite electrode was successfully applied for the detection of trace amounts of the ACV in the blood serum samples.
Variation in the social organization of gorillas: Life history and socioecological perspectives
Authors: Robbins Martha M. , Robbins Andrew M. 
Published: October 2018

AbstractA focus of socioecological research is to understand how ecological, social, and life history factors influence the variability of social organization within and between species. The genus Gorilla exhibits variability in social organization with western gorilla groups being almost exclusively one‐male, yet approximately 40% of mountain gorilla groups are multimale. We review five ultimate causes for the variability in social organization within and among gorilla populations: human disturbance, ecological constraints on group size, risk of infanticide, life history patterns, and population density. We find the most evidence for the ecological constraints and life history hypotheses, but an over‐riding explanation remains elusive. The variability may hinge on variation in female dispersal patterns, as females seek a group of optimal size and with a good protector male. Our review illustrates the challenges of understanding why the social organization of closely related species may deviate from predictions based on socioecological and life history theory.
Application of chia (Salvia hispanica) seeds as a functional component in the fortification of pineapple jam
Authors: Nduko John M. , Maina Rita W. , Muchina Rose K. , Kibitok Simon K. 
Published: October 2018

AbstractThis study aimed at producing chia seed‐fortified pineapple jam and evaluation of its physicochemical and sensory characteristics. Five pineapple jam formulations were developed, starting with the basic formulation (jam 1/control) containing sucrose and added pectin. The other jams (jam 2, jam 3, jam 4, and jam 5) had sucrose and pectin but with chia seeds added at rates of 6.25, 12.5, 25, and 50% w/w, respectively. Crude protein of the jams was analyzed through macro Kjeldahl method, and the crude fiber was estimated by the Weende method. Thirty‐two semi‐trained panelists performed sensory evaluation test of the developed jams using 5‐point hedonic scale. Chia pineapple jam had golden color compared to control pineapple jam, which had yellow color. The fresh chia pineapple jams had significantly (p < 0.05) different protein and crude fiber contents in each sample. The protein content in the control was 0.53%, while it ranged between 1.60 and 8.60% for the chia seed‐fortified jams. For crude fiber, the values were 4.83% for the control and 5.38, 9.08, 13.33, and 21.02% for jam 2, jam 3, jam 4, and jam 5, respectively. General acceptability and sensory evaluation (flavor, color, and texture) showed significant (p < 0.05) differences compared to the control, while spreadability had no significant (p > 0.05) differences. The information obtained from this study indicates that chia‐fortified pineapple jam could be produced with favorable sensory attributes that could be used for jam making and other processed products to benefit from the functional components in the chia seeds.
Effects of state education requirements for substance use prevention
Authors: Carpenter Christopher S. , Bruckner Tim A. , Domina Thurston , Gerlinger Julie , Wakefield Sara 
Published: October 2018

AbstractWe provide the first evidence on the effects of state laws requiring students to receive education about alcohol, tobacco, and other drugs using data on over a million youths from the 1976–2010 Monitoring the Future study. In difference‐in‐differences and event‐study models, we find robust evidence that these laws significantly reduced recent alcohol and marijuana use among high school seniors by 1.6–2.8 percentage points, or about 8–10% of the overall decline over this period. Our results suggest that information interventions can reduce youth substance use.
Diversification and the benefits of using returns standardized by range‐based volatility estimators
Authors: Miralles‐Quirós José Luis , Miralles‐Quirós María Mar , Nogueira José Manuel 
Published: October 2018

AbstractThe aim of our research is to analyse the benefits for the U.S. investors of combining their domestic exchange trade fund (ETF) with ETFs, which track other developed markets such as the United Kingdom, Japan, Germany, and France. We evaluate the out‐of‐sample performance of six strategies using the returns and volatility forecasts from a VAR Asymmetric Dynamic Conditional Correlation GARCH approach where returns standardized by range‐based volatility estimators were used as endogenous variables. The initial outperformances of some strategies using classic returns were significantly improved when returns were standardized by the Garman–Klass precise volatility estimator. Additionally, we find a large decrease in the weights of the North American ETF in the best performing strategies, meaning that it is possible to obtain benefits from diversification. These findings are relevant not only for academics but also for active professional managers who can use this technique to add value to their international diversification strategies.