bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differences in Engineered Nanoparticle Surface Physicochemistry Revealed by Investigation of Changes in Copper Bioavailability During Sorption to Nanoparticles in the Aqueous Phase
Authors: Patsiou Danae , Kalman Judit , Fernandes Teresa F. , Henry Theodore B. 
Published: January 2019

Abstract

Sorption of chemical substances to nanoparticles (NPs) in the aqueous phase strongly influences NP physicochemisty, and investigations of these complex interactions can provide important insights into the environmental fate of NPs. The objective of the present study was to use differences in copper (Cu) bioavailability to investigate aqueous-phase sorption with NPs that had different physicochemical characteristics (silicon [Si], perovskite, and titanium dioxide NPs [TiO2 NPs]). Sorption of Cu with NPs was assessed by the presence of adsorbent in water and onto the NP surface after ultracentrifugation, and by changes in Cu bioavailability under static conditions during exposure of larval zebrafish, as well as under conditions of continuous agitation during exposure of the alga Chlorella vulgaris. The presence of TiO2 NPs reduced total Cu in the water column and Cu bioavailability (measured by growth inhibition, mortality, and metallothionein 2 gene expression), confirming Cu sorption to TiO2 NPs. Nanoparticle surface area was the most important factor that affected Cu sorption, as indicated by less bioavailable Cu in the presence of smaller TiO2 NPs. The surface area effect was consistent regardless of exposure conditions (alga, continuous agitation; zebrafish, static water) and was further supported by the fact that the lowest total Cu concentration in the water column was found in the presence of the smallest NP. The results differed with other NP types, for example, silicon NPs, in which Cu sorption was indicated by analytical chemistry, but sorption was not sufficient to significantly alter Cu bioavailability. The bioavailability tests did not indicate Cu sorption with perovskite NPs. The results demonstrate that surface area critically influences sorption, that Cu sorption as measured by bioavailability is not affected by agitation or static conditions, and that Cu sorption differs among types of NPs, indicating differences in their surface physicochemistry. Environ Toxicol Chem 2019;9999:1–11. © 2019 SETAC
Abstract
Copper sorption (%) as indicated by 4 independent analyses, conducted in the present study, show a positive correlation with the surface area (calculated by the reported manufactured particle diameter) of the nanoparticles (NPs) used in the present study (cm2). The analyses were as follows: the differences in the 72-h median effect concentration (EC50; Δ 72-h EC50) in the presence of NPs of different surface area generated by Chlorella vulgaris tests, the Δ 96-h median lethal concentration (LC50) of the zebrafish larvae tests, the differences in mt2 gene expression, and the curves generated by analytical chemistry (inductively coupled plasma–mass spectrometry [ICP-MS]), with R2 values of 0.90, 0.88, 0.81, and 0.99, respectively.
Applying Multiphase Sampling to Selecting Testlets With Constraints on Item Blocks
Authors: Qian Jiahe , Gu Lixiong , Li Shuhong 
Published: January 2019

AbstractIn assembling testlets (i.e., test forms) with a pool of new and used item blocks, test security is one of the main issues of concern. Strict constraints are often imposed on repeated usage of the same item blocks. Nevertheless, for an assessment administering multiple testlets, a goal is to select as large a sample of testlets as possible. In this study, the algorithm of multiphase sampling was applied to selecting and augmenting the sample of testlets to be administered. Several topics related to the algorithm are discussed, such as the termination of the algorithm, the dynamics of sample size, and the effectiveness of the algorithm. A real database of testlets was used in the study.
Using Artificial Neural Networks to forecast Exchange Rate, including VAR‐VECM residual analysis and prediction linear combination
Authors: Parot Alejandro , Michell Kevin , Kristjanpoller Werner D. 
Published: January 2019

SummaryThe Euro US Dollar rate is one of the most important exchange rates in the world, making the analysis of its behavior fundamental for the global economy and for different decision‐makers at both the public and private level. Furthermore, given the market efficiency of the EUR/USD exchange rate, being able to predict the rate's future short‐term variation represents a great challenge. This study proposes a new framework to improve the forecasting accuracy of EUR/USD exchange rate returns through the use of an Artificial Neural Network (ANN) together with a Vector Auto Regressive (VAR) model, Vector Error Corrective model (VECM), and post‐processing. The motivation lies in the integration of different approaches, which should improve the ability to forecast regarding each separate model. This is especially true given that Artificial Neural Networks are capable of capturing the short and long‐term non‐linear components of a time series, which VECM and VAR models are unable to do. Post‐processing seeks to combine the best forecasts to make one that is better than its components. Model predictive capacity is compared according to the Root Mean Square Error (RMSE) as a loss function and its significance is analyzed using the Model Confidence Set. The results obtained show that the proposed framework outperforms the benchmark models, decreasing the RMSE of the best econometric model by 32.5% and by 19.3% the best hybrid. Thus, it is determined that forecast post‐processing increases forecasting accuracy.
The bring‐your‐own‐device unintended administrator: A perspective from Zimbabwe
Authors: Musarurwa Alfred , Flowerday Stephen , Cilliers Liezel 
Published: January 2019

AbstractAs bring your own device (BYOD) becomes part of workplace tools for employees in Zimbabwe, the responsibility to implement information security management methods, which was traditionally confined to the information technology (IT) employees, has extended to all the employees, who now become unintended administrators because of the usage of their devices. The purpose of this paper is to show how banks can mitigate the information security risks caused by the unintended administrator using the BYOD information security behavioural (BISB) model. A literature review of the BYOD information security and organisational information security culture was conducted. A questionnaire was developed from the literature and sent to 270 bank employees in Zimbabwe. A total of 205 employees participated, and 179 completed the questionnaire. An expert review consisting of chief information officers (CIOs) at banks in Zimbabwe was conducted to evaluate the proposed model. From the literature review, individual traits of attitude, knowledge, and habit, as well as organisational traits of the environment, governance, and training, were identified as key traits that constituted the constructs of the BISB model. The overall theme of this paper is that banks can mitigate the BYOD information security challenges by using of the BISB model.
The evaluation of the anti‐cancer drug elesclomol that forms a redox‐active copper chelate as a potential anti‐tubercular drug
Authors: Ngwane Andile H. , Petersen Ray‐Dean , Baker Bienyameen , Wiid Ian , Wong Ho Ning , Haynes Richard K. 
Published: January 2019

AbstractThe observations that the innate immune system employs copper to eliminate bacterial infection and that resistance to copper enhances virulence of Mycobacterium tuberculosis (Mtb) prompted us to examine the effects the anti‐cancer agent elesclomol on Mtb. As a bis‐thionohydrazide, elesclomol chelates with copper to form a copper complex in situ that via redox cycling of the metal ion greatly enhances oxidative stress in tumour cells. Here, we demonstrate that elesclomol is relatively potent against Mtb H37Rv with minimum inhibitory concentration of 10 μM (4 mg/L) and against multidrug resistant clinical isolates of Mtb, displays additive interactions with known tuberculosis drugs such as isoniazid and ethambutol, and a synergistic interaction with rifampicin. Controlled supplementation of elesclomol with copper in culture medium increased Mtb sensitivity by >65 fold. Overall, the activities of elesclomol in principle indicate the possibility of repurposing elesclomol or designing new thionohydrazides as potential drugs for use against Mtb. © 2019 IUBMB Life, 71(5):532–538, 2019
Design, Synthesis, and Biological Evaluation of 3,5‐Disubstituted 2‐Pyrazineamide Derivatives as Antitubercular Agents
Authors: Gangarapu Nagaraja Reddy , Ranganatham A. , Reddy Eeda Koti , Surendra H. D. , Sajith Ayyiliath M. , Yellappa Shivaraj , Chandrasekhar Kothapalli Bannoth 
Published: January 2019

A novel series of 3,5‐disubstituted‐2‐pyrazineamide derivatives (5a–5o) were synthesized and studied for their potential as antitubercular agents. Among them, the compounds 5a, 5g, and 5m showed the good minimal inhibitory concentration of 20, 25, and 25 μg/mL, respectively. The compound 5a displayed excellent minimum inhibitory concentration of 10 μg/mL and is four times more potent compared with the standard drug, rifampicin concentration. In silico docking studies revealed that the compounds 5a and 5c can bind strongly in the active site of 2FUM enzyme and prevent enzyme–substrate interactions. In addition, in silico docking studies were calculated, and based on the data obtained, compound 5a displayed excellent drug‐like properties.
“Is it making any difference?” A qualitative study examining the treatment‐taking experiences of asymptomatic people living with HIV in the context of Treat‐all in Eswatini
Authors: Horter Shona , Wringe Alison , Thabede Zanele , Dlamini Velibanti , Kerschberger Bernhard , Pasipamire Munyaradzi , Lukhele Nomthandazo , Rusch Barbara , Seeley Janet 
Published: January 2019

AbstractIntroductionTreat‐all is being implemented in several African settings, in accordance with 2015 World Health Organisation guidelines. The factors known to undermine adherence to antiretroviral therapy (ART) may change in the context of Treat‐all, where people living with HIV (PLHIV) increasingly initiate ART at earlier, asymptomatic stages of disease, soon after diagnosis. This paper aimed to examine the asymptomatic PLHIV's experiences engaging with early ART initiation under the Treat‐all policy, including how they navigate treatment‐taking over the longer term.MethodsA longitudinal qualitative study was conducted within a Médecins Sans Frontières/Ministry of Health Treat‐all pilot in Shiselweni, southern Eswatini. The Treat‐all pilot began in October 2014, adopted into national policy in October 2016. Participants were recruited purposively to include newly diagnosed, clinically asymptomatic PLHIV with a range of treatment‐taking experiences, and healthcare workers (HCW) with various roles. This analysis drew upon a sub‐sample of 17 PLHIV who had been on ART for at least 12 months, with mean 20 months on ART at first interview, and who undertook three interviews each. Additionally, 20 HCWs were interviewed once. Interviews were conducted from August 2016 to September 2017. Data were analysed thematically using coding, drawing upon principles of grounded theory, and aided by Nvivo 11.ResultsIt was important for PLHIV to perceive the need for treatment, and to have evidence of its effectiveness to motivate their treatment‐taking, thereby supporting engagement with care. For some, coming to terms with a HIV diagnosis or re‐interpreting past illnesses as signs of HIV could point to the need for ART to prevent health deterioration and prolong life. However, others doubted the accuracy of an HIV diagnosis and the need for treatment in the absence of symptoms or signs of ill health, with some experimenting with treatment‐taking as a means of seeking evidence of their need for treatment and its effect. Viral load monitoring appeared important in offering a view of the effect of treatment on the level of the virus, thereby motivating continued treatment‐taking.ConclusionsThese findings highlight the importance of PLHIV perceiving need for treatment and having evidence of the difference that ART is making to them for motivating treatment‐taking. Patient support should be adapted to address these concerns, and viral load monitoring made routinely available within Treat‐all care, with communication of suppressed results emphasized to patients.
Bilateral cardiac sympathetic denervation of a recurrent refractory ventricular tachycardia occurring after catheter ablation of atrial fibrillation and outflow tract premature ventricular contractions
Authors: Yagishita Atsuhiko , Goya Masahiko , Takahashi Yoshihide , Ishibashi Hironori , Akiyoshi Kikou , Sekigawa Masahiro , Maeda Shingo , Kawabata Mihoko , Okubo Kenichi , Hirao Kenzo 
Published: January 2019

AbstractRecent studies have demonstrated the utility of cardiac sympathetic denervation (CSD) in patients with ventricular tachycardia (VT) refractory to antiarrhythmic drugs and catheter or surgical ablation. We present our experience with bilateral CSD in a patient with a recurrent VT despite attempts at treatment with catheter ablation and antiarrhythmic drugs, and this is the first description of the successful management of an idiopathic refractory VT with a bilateral CSD and concomitant oral amiodarone, occurring after catheter ablation of persistent atrial fibrillation and idiopathic outflow tract premature ventricular contractions.
Addressing Disaster Exposure Measurement Issues With Latent Class Analysis
Authors: Felix Erika D. , Binmoeller Cecile , Nylund‐Gibson Karen , Benight Charles C. , Benner Aprile D. , Terzieva Antoniya 
Published: January 2019

AbstractDisaster exposure can put survivors at greater risk for subsequent mental health (MH) problems. Within the field of disaster MH research, it is important to understand how the choice of analytic approaches and their implicit assumptions may affect results when using a disaster exposure measure. We compared different analytic strategies for quantifying disaster exposure and included a new analytic approach, latent class analysis (LCA), in a sample of parents and youth. Following exposure to multiple floods in Texas, a sample of 555 parents and 486 youth were recruited. Parents were predominantly female (70.9%) and White (60.8%). Parents were asked to have their oldest child between the ages of 10 and 19 years old participate (M = 13.74 years, SD = 2.57; 52.9% male). Participants completed measures on disaster exposure, posttraumatic stress, depression, and anxiety. The LCA revealed four patterns of exposure in both parents and youth: high exposure (15.5% parent, 9.5% child), moderate exposure (19.8% parent, 28.2% child), community exposure (45.9% parent, 34.4% child), and low exposure (18.8% parent, 27.8% child). In terms of MH, there were similarities across analytic approaches, but the LCA highlighted a threshold effect, with the high exposure class doing worse than all others, d = 1.12. These results have important implications in understanding the different exposure experiences of survivors and the linkage to MH outcomes. The findings are also informative in the development and use of screening tools used in postdisaster contexts in determining who may or may not need MH services.
The energy based devices for vaginal “rejuvenation,” urinary incontinence, vaginal cosmetic procedures, and other vulvo‐vaginal disorders: An international multidisciplinary expert panel opinion
Authors: Digesu Giuseppe Alessandro , Tailor Visha , Preti Mario , Vieira‐Baptista Pedro , Tarcan Tufan , Stockdale Colleen , Mourad Sherif 
Published: January 2019

AimsEnergy‐based devices using radiofrequency and laser technologies have gained popularity as therapies for vaginal atrophy, urinary incontinence, and vaginal prolapse. They have been promoted by cosmetic and aesthetic industries for vaginal “laxity” and vaginal “rejuvenation,” both of which are undefined conditions and terms. This article aims to review the current available literature and its quality on this emerging technology.MethodsAn international panel of gynaecologists, urogynaecologists, and urologists undertook a review of the available published literature, identifying articles, guidance, and society statements on the use vaginal energy‐based devices.ResultsThere is currently no formal guidance for the use of vaginal energy based therapies. No randomized controlled trials have been published. No comparative studies to existing treatment has been carried out. Studies suggest that vaginal laser can be used in the treatment of vaginal prolapse or “vaginal laxity” and stress urinary incontinence with no quality evidence supporting the use of the therapy for vaginal atrophy or lichen sclerosis.ConclusionsThis international group propose that whilst there remains a paucity of good quality data describing the safety, benefits, and appropriate use of vaginal radiofrequency or laser treatments in gynaecology and urogynaecology, a consensus best practice document by an established scientific community needs to be developed.
Amino Acid Functionalized Single−Wall Carbon Nanotubes in Thermoresponsive Drug Delivery Systems: A Computational Study
Authors: Ghadari Rahim , Kashefi Ashkan 
Published: January 2019

AbstractIn this research, a computational study was conducted to evaluate the usability of amino acid functionalized single−walled carbon nanotubes (AA−SWCNTs) in the thermoresponsive drug delivery systems. The Taxol (TXL) was used as a model lipophilic drug and temperatures of 300, 310, and 315 K were selected. At first, docking studies were carried out to find the binding mode of the TXL to the surface of AA−SWCNTs. Then, molecular dynamic studies were performed. The molecular mechanics/generalized Born surface area (MM/GBSA) approach was used to evaluate the binding energies of AA−SWCNT/TXL systems. Based on the calculated binding energies in the three mentioned temperatures, Gln−, Gly−, Pro−, and Ser−SWCNT have the ability to release the TXL by increase of temperature; the weaker van der Waals interactions at higher temperature can be regarded as the origin of such observation. From another point of view, Gln− and Ser−SWCNT showed improved solubility in the aqueous media by considering the calculated logP values. These two systems are good candidates to be used in the thermoresponsive drug delivery systems.
Chromophore Arrays Constructed in the Major Groove of DNA Duplexes Using a Post‐Synthetic Strategy
Authors: Nakamura Mitsunobu , Matsui Yuki , Takada Tadao , Yamana Kazushige 
Published: January 2019

AbstractThe construction of zipper‐like chromophore‐arrays in the major groove of duplex DNA remains a challenge because only a few chromophores for this application have been discovered. To address the challenge, dual‐chromophore labeled DNAs having a self‐complementary sequence were prepared using a solid‐phase, post‐synthetic, copper‐catalyzed, alkyne‐azide cycloaddition. The resulting chromophore‐arrays on the labeled DNA duplexes were characterized. The dual‐tetraphenylethene (TPE) or dual‐pyrene (Py) labeled DNA formed self‐complementary B‐form duplexes and resulted in the construction of chromophore‐arrays in the major groove. The TPE‐arrays, in which TPEs were arranged in a zipper‐like fashion, slightly destabilized the duplex because of their bulkiness and exhibited aggregation‐induced‐emission. The Py‐arrays, in which Pys were not arranged in a zipper‐like fashion, had no effect on duplex stability and exhibited weak excimer emission because Py was sufficiently small for free rotation in the major groove.
A 3‐Fluoro‐4‐hexylthiophene‐Based Wide Bandgap Donor Polymer for 10.9% Efficiency Eco‐Friendly Nonfullerene Organic Solar Cells
Authors: Yu Jeong Eun , Jeon Sung Jae , Choi Jun Young , Han Yong Woon , Ko Eui Jin , Moon Doo Kyung 
Published: January 2019

AbstractNonfullerene organic solar cells (NFOSCs) are attracting increasing academic and industrial interest due to their potential uses for flexible and lightweight products using low‐cost roll‐to‐roll technology. In this work, two wide bandgap (WBG) polymers, namely P(fTh‐BDT)‐C6 and P(fTh‐2DBDT)‐C6, are designed and synthesized using benzodithiophene (BDT) derivatives. Good oxidation stability and high solubility are achieved by simultaneously introducing fluorine and alkyl chains to a single thiophene (Th) unit. Solid P(fTh‐2DBDT)‐C6 films present WBG optical absorption, suitable frontier orbital levels, and strong π–π stacking effects. In addition, P(fTh‐2DBDT)‐C6 exhibits good solubility in both halogenated and nonhalogenated solvents, suggesting its suitability as donor polymer for NFOSCs. The P(fTh‐2DBDT)‐C6:3,9‐bis(2‐methylene‐(3‐(1,1‐dicyanomethylene)‐indanone))‐5,5,11,11‐tetrakis(5‐hexylthienyl)‐dithieno[2,3‐d:2′,3′‐d′]‐s‐indaceno[1,2‐b:5,6‐b′]dithiophene (ITIC‐Th) based device processed using chlorobenzene/1,8‐diiodooctane (CB/DIO) exhibits a remarkably high power conversion efficiency (PCE) of 11.1%. Moreover, P(fTh‐2DBDT)‐C6:ITIC‐Th reaches a high PCE of 10.9% when processed using eco‐friendly solvents, such as o‐xylene/diphenyl ether (DPE). The cell processed using CB/DIO maintains 100% efficiency after 1272 h, while that processed using o‐xylene/DPE presents a 101% increase in efficiency after 768 h and excellent long‐term stability. The results of this study demonstrate that simultaneous fluorination and alkylation are effective methods for designing donor polymers appropriate for high‐performance NFOSCs.
Thermopower Modulation Clarification of the Operating Mechanism in Wide Bandgap BaSnO3–SrSnO3 Solid‐Solution Based Thin Film Transistors
Authors: Sanchela Anup V. , Wei Mian , Cho Hai Jun , Ohta Hiromichi 
Published: January 2019

AbstractThe transparent oxide semiconductor (TOS) with large bandgap (Eg ≈ 4 eV) based thin‐film transistors (TFTs) showing both high carrier mobility and UV–visible transparency has attracted increasing attention as a promising component for next generation optoelectronics. Among TOSs, BaSnO3–SrSnO3 solid‐solutions (Eg = 3.5–4.2 eV) are good candidates because the single crystal shows very high mobility. However, the TFT performance has not been optimized due to the lack of fundamental knowledge especially the effective thickness (teff) and the carrier effective mass (m*). Here, it is demonstrated that the electric field thermopower (S) modulation method addresses this problem by combining with the standard volume carrier concentration (n3D) dependence of S measurements. By comparing the electric field accumulated sheet carrier concentration (n2D) and n3D at same S, it is clarified that the teff (n2D/n3D) of the conducting channel becomes thicker with increasing Sr concentration, whereas the m* becomes lighter. The former would be due to the increase of Eg and latter would be due to the enhancement of overlap population of neighboring Sn 5s orbitals. The present analyses technique is useful to experimentally clarify the teff and m*, and essentially important to realize advanced TOS‐based TFTs showing both high optical transparency and high mobility.