bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unique β‐Turn Peptoid Structures and Their Application as Asymmetric Catalysts
Authors: Darapaneni Chandra Mohan , Ghosh Pritam , Ghosh Totan , Maayan Galia 
Published: March 2020

AbstractPeptoids, N‐substituted glycine oligomers, represent an important class of peptidomimetics that can fold into three‐dimensional structures in solution. Most of the folded peptoid structures, however, resemble helices, and this can limit their applications, specifically in asymmetric catalysis. In this work, for the first time, unique examples of pyrrolidine‐based β‐turn‐like peptoids are described and characterized, both in the solid state, by single‐crystal X‐ray analysis, and in solution, by circular dichroism spectroscopy. Furthermore, their highly efficient and enantioselective catalytic activity for the production of γ‐nitro aldehydes by asymmetric Michael reaction in water was demonstrated. The structural properties and DFT‐D3 calculations of the new β‐turn‐like peptoids, as well as catalytic and spectroscopic studies on designed pyrrolidine‐based helical peptoids, suggest that the β‐turn structure plays a key role in the stereoselectivity of the catalytic reaction.
Enantioselective 1,3‐Dipolar [6+4] Cycloaddition of Pyrylium Ions and Fulvenes towards Cyclooctanoids
Authors: McLeod David , Cherubini‐Celli Alessio , Sivasothirajah Nisanhi , McCulley Christina H. , Christensen Mette Louise , Jørgensen Karl Anker 
Published: March 2020

AbstractOrganocatalytic enantioselective 1,3‐dipolar [6+4] cycloadditions of pyrylium ion intermediates with fulvenes promoted by a chiral primary amine catalyst have been developed to proceed in moderate to good yields and high enantioselectivities. The resultant chiral bicyclo[6.3.0]undecane scaffold containing a transannular bridging ether is densely functionalised providing a rigid scaffold for further manipulations. Computational studies give important insights into the role of the primary amine catalyst. Analysis of the reaction shows that the catalytic reaction proceeds in a step‐wise manner and rationalises the stereochemical outcome of the reaction. Several stereoselective complexity‐generating transformations, facilitated by the diverse functional groups and transannular bridge, are presented, highlighting the versatility of the core towards a number of the cyclooctanoid natural products.
Oxygen Reduction and Evolution on Ni‐modified Co3O4(1 1 1) Cathodes for Zn–Air Batteries: A Combined Surface Science and Electrochemical Model Study
Authors: Buchner Florian , Eckardt Markus , Böhler Timo , Kim Jihyun , Gerlach Jasmin , Schnaidt Johannes , Behm R. Jürgen 
Published: March 2020

AbstractThe performance of structurally and chemically well‐defined Ni‐free and Ni‐modified single‐crystalline Co3O4(1 1 1) thin‐film electrodes in the oxygen reduction and evolution reactions (ORR and OER) was investigated in a combined surface science and electrochemistry approach. Pure and Ni‐modified Co3O4(1 1 1) film electrodes were prepared and characterized under ultrahigh‐vacuum conditions by scanning tunneling microscopy and X‐ray photoelectron spectroscopy. Both Ni decoration (by post‐deposition of Ni) and Ni doping (by simultaneous vapor deposition of Ni, Co, and O2) induced distinct differences in the base cyclic voltammograms in 0.5 m KOH at potentials higher than 0.7 V compared with Co3O4(1 1 1) electrodes. Also, all oxide film electrodes showed a higher overpotential for the ORR but a lower one for the OER than polycrystalline Pt. Ni modification significantly improved the ORR current densities by increasing the electrical conductivity, whereas the OER onset of approximately 1.47 VRHE (RHE: reversible hydrogen electrode) at 0.1 mA cm−2 was almost unchanged.
Tailored Gas Adsorption Properties of Electrospun Carbon Nanofibers for Gas Separation and Storage
Authors: Kretzschmar Ansgar , Selmert Victor , Weinrich Henning , Kungl Hans , Tempel Hermann , Eichel Rüdiger‐A. 
Published: March 2020

AbstractCarbon nanofibers (CNFs) derived from electrospun polyacrylonitrile (PAN) were investigated with respect to their gas adsorption properties. By employing CO2 adsorption measurements, it is shown that the adsorption capacity and selectivity of the fibers can be tailored by means of the applied carbonization temperature. General pore properties of the CNFs were identified by Ar adsorption measurements, whereas CO2 adsorption measurements provided information about the ultramicroporosity, adsorption energies, and adsorption capacities. Ideal adsorbed solution theory (IAST) selectivities under practically relevant conditions were determined by evaluation of single‐component data for N2 and CO2. Especially for low carbonization temperatures, the CNFs exhibit very good low‐pressure adsorption performance and excellent CO2/N2 IAST selectivities of 350 at 20 mbar and 132 at 1 bar, which are attributed to a molecular‐sieve effect in very narrow slit pores. These IAST selectivities are some of the highest values for carbon materials reported in the literature so far and the highest IAST selectivities for as‐prepared, non‐post‐treated carbon ever.
Inkjet Printed Multi‐walled Carbon Nanotube Sensor for the Detection of Lead in Drinking Water
Authors: Rahm Connor E. , Torres‐Canas Fernando , Gupta Pankaj , Poulin Philippe , Alvarez Noe T. 
Published: March 2020

AbstractElectroanalytical methods can be used for the reliable detection of the toxic heavy metal lead in drinking water samples. Inkjet printed electrodes have potential for the rapid and affordable assessment of drinking water. Researchers have shown the electrochemical sensing applicability of inkjet printed electrodes. In this work, Pb2+ was detected using an inkjet printed multi‐walled carbon nanotube (IJP‐MW‐CNT) electrode with silver tracks printed underneath. The silver tracks provide the sensor with the conductivity needed for sensitive measurements. MW‐CNT were dispersed in water using bile salts as a surfactant to prepare the ink. The IJP‐MW‐CNT electrode was used as the working electrode with a platinum wire and Ag/AgCl as auxiliary and reference electrode, respectively. The electrodes performance was optimized in 0.1 M acetate buffer (pH=4.3) and had two linear ranges of 5 to 20 ppb (R2=0.99) with a sensitivity of 38 nA/ppb and 20 to 50 ppb (R2=0.98) with a sensitivity of 15 nA/ppb and a limit of detection (LOD) of 1.0 ppb for Pb2+. The analytical applicability of electrode was determined by constructing a calibration curve in an unaltered drinking water sample (i. e.) Cincinnati tap water with two linear ranges of 15 to 40 ppb (R2=0.99) with a sensitivity of 1.5 nA/ppb and 40 to 70 ppb (R2=0.99) with a sensitivity of 3.5 nA/ppb and a LOD of 1.0 ppb for Pb2+. Effects of copper and cadmium as potential interferents are reported.
Assessing Benthic Bioaccumulation of Polychlorinated Dioxins/Furans and Polychlorinated Biphenyls in the Lower Passaic River (NJ, USA) Based on In Situ Passive Sampling
Authors: Khairy Mohammed A. , Lohmann Rainer 
Published: March 2020

Abstract
Passive sampling has emerged as a promising tool to assess the presence of hydrophobic organic contaminants (HOC) in water, sediment, and biota, such as polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) or polychlorinated biphenyls (PCBs). Previous work evaluated the ability of passive samplers to predict the bioavailability of sedimentary HOCs mostly in the laboratory, often for marine organisms. The present study assessed the use of low-density polyethylene (LDPE) to derive freely dissolved concentrations of PCDD/Fs and PCBs in porewater in situ versus ex situ and in river water. An LDPE-based multisampler system was deployed at 4 locations along the lower Passaic River (NJ, USA) in sediment and the water column, where sediment and benthic species samples were also collected. Good agreement was generally observed for PCDD/F and PCB concentrations comparing in situ and ex situ approaches (within 0.30–39%). Significant linear relationships were derived between log LDPE–based and log lipid–based concentrations of PCDD/Fs and PCBs. The in situ multisampler system showed promise to derive HOC concentrations in porewater and river water and to predict the bioaccumulation potential of HOCs in benthic biota. Environ Toxicol Chem 2020;39:1174–1185. © 2020 SETAC
Relational ownership, institutional context, and internationalization of state‐owned enterprises: When and how are multinational co‐owners a plus?
Authors: Mariotti Sergio , Marzano Riccardo 
Published: March 2020

AbstractResearch SummaryWe investigate when and how a foreign multinational enterprise by acting as a relational co‐owner helps the internationalization of hybrid state‐owned enterprises. We merge the “liability of stateness” and the “government as strategist” perspectives with an institutional context‐based approach. We claim that the effect of multinational enterprise relational co‐ownership is contingent on the countries' institutional settings. It is positive at lower levels of both institutional coordination (as a measure of variety of capitalism) and government effectiveness. This effect is mitigated as coordination and government effectiveness increase. Further, a comparison between hybrid state‐owned and private‐owned enterprises shows that the magnitude of the contribution by foreign relational co‐owners to internationalization is also moderated by institutional variables.Managerial SummaryOpportunities and challenges for state‐owned enterprises (SOEs) to expand their activities abroad and to climb the rankings of the world‐class multinational corporations have been emerging. However, these enterprises often lack the experience required for internationalization and suffer from the inward‐looking orientation and political interferences of their national governments. This is especially true when governments are ineffective in getting things done, and the local institutions limit their role to sustaining a positive regulatory internal market, but with no strategy to promote multinational state‐owned players. Under these conditions, the co‐ownership with a foreign proactive industrial partner can be an effective strategy for SOEs to overcome the difficulties in entering foreign markets.
Impact of b‐value on estimates of apparent fibre density
Authors: Genc Sila , Tax Chantal M. W. , Raven Erika P. , Chamberland Maxime , Parker Greg D. , Jones Derek K. 
Published: March 2020

AbstractRecent advances in diffusion magnetic resonance imaging (dMRI) analysis techniques have improved our understanding of fibre‐specific variations in white matter microstructure. Increasingly, studies are adopting multi‐shell dMRI acquisitions to improve the robustness of dMRI‐based inferences. However, the impact of b‐value choice on the estimation of dMRI measures such as apparent fibre density (AFD) derived from spherical deconvolution is not known. Here, we investigate the impact of b‐value sampling scheme on estimates of AFD. First, we performed simulations to assess the correspondence between AFD and simulated intra‐axonal signal fraction across multiple b‐value sampling schemes. We then studied the impact of sampling scheme on the relationship between AFD and age in a developmental population (n = 78) aged 8–18 (mean = 12.4, SD = 2.9 years) using hierarchical clustering and whole brain fixel‐based analyses. Multi‐shell dMRI data were collected at 3.0T using ultra‐strong gradients (300 mT/m), using 6 diffusion‐weighted shells ranging from b = 0 to 6,000 s/mm2. Simulations revealed that the correspondence between estimated AFD and simulated intra‐axonal signal fraction was improved with high b‐value shells due to increased suppression of the extra‐axonal signal. These results were supported by in vivo data, as sensitivity to developmental age‐relationships was improved with increasing b‐value (b = 6,000 s/mm2, median R2 = .34; b = 4,000 s/mm2, median R2 = .29; b = 2,400 s/mm2, median R2 = .21; b = 1,200 s/mm2, median R2 = .17) in a tract‐specific fashion. Overall, estimates of AFD and age‐related microstructural development were better characterised at high diffusion‐weightings due to improved correspondence with intra‐axonal properties.
Volumetric medical image compression using inter‐slice correlation switched prediction approach
Authors: Sharma Urvashi , Sood Meenakshi , Puthooran Emjee 
Published: March 2020

AbstractWith the advancement in medical data acquisition and telemedicine systems, image compression has become an important tool for image handling, as the tremendous amount of data generated in medical field needs to be stored and transmitted effectively. Volumetric MRI and CT images comprise a set of image slices that are correlated to each other. The prediction of the pixels in a slice depends not only upon the spatial information of the slice, but also the inter‐slice information to achieve compression. This article proposes an inter‐slice correlation switched predictor (ICSP) with block adaptive arithmetic encoding (BAAE) technique for 3D medical image data. The proposed ICSP exploits both inter‐slice and intra‐slice redundancies from the volumetric images efficiently. Novelty of the proposed technique is in selecting the correlation coefficient threshold (Tϒ) for switching of ICSP. Resolution independent gradient edge detector (RIGED) at optimal prediction threshold value is proposed for intra‐slice prediction. Use of RIGED, which is modality and resolution independent, brings the novelty and improved performance for 3D prediction of volumetric images. BAAE is employed for encoding of prediction error image to resulting in higher compression efficiency. The proposed technique is also extended for higher bit depth volumetric medical images (16‐bit depth) presenting significant compression gain of 3D images. The performance of the proposed technique is compared with the state‐of‐the art techniques in terms of bits per pixel (BPP) for 8‐bit depth and was found to be 31.21%, 27.55%, 21.89%, and 2.39% better than the JPEG‐2000, CALIC, JPEG‐LS, M‐CALIC, and 3D‐CALIC respectively. The proposed technique is 11.86%, 8.56%, 7.97%, 6.80%, and 4.86% better than the M‐CALIC, 3D CALIC, JPEG‐2000, JPEG‐LS and CALIC respectively for 16‐bit depth image datasets. The average value of compression ratio for 8‐bit and 16‐bit image dataset is obtained as 3.70 and 3.11 respectively by the proposed technique.
Intensified acidophilic bioleaching of multi‐metals from waste printed circuit boards (WPCBs) of spent mobile phones
Authors: Erust Ceren , Akcil Ata , Tuncuk Aysenur , Panda Sandeep 
Published: March 2020

AbstractBACKGROUNDWaste printed circuit boards (WPCBs) are a resource containing a wide array of metals and are of great importance because their metal concentration is much greater than that in the ores. Previous studies have been devoted mostly to copper (Cu) bioleaching from WPCBs because it has the highest proportion ( ∼ 10–30%) of all their component metallic elements. The present study focused on an intensified mixed meso‐acidophilic bacterial leaching of multi‐metals from WPCBs of spent mobile phones, with the system operating under high oxido‐reductive potentials (HORPs). Inductively coupled plasma‐optical emission spectrometry (ICP‐OES), X‐ray diffraction (XRD) and scanning electron microscopy‐energy dispersive X‐ray (SEM‐EDX) characterization indicated the WCPB sample had recoverable contents of Cu, aluminium (Al), nickel (Ni) and zinc (Zn) which were targeted for bioleaching.RESULTSShake flask optimization studies, under HORP >750 mV indicated dissolutions of 98.1% Cu, 55.9% Al, 79.5% Ni and 66.9% Zn under optimized conditions of 9 g L–1 iron [Fe (II)], 10% pulp density, initial pH 1.8 and 10% (v/v) as initial inoculum. Under these conditions, at ORP >650 mV, 97.3% Cu, 55.8% Al, 79.3% Ni and 66.8% Zn were achieved in bench‐scale (1 L) bioreactor systems without any significant reduction in efficiency (compared to shake flasks) after 8 days of operation.CONCLUSIONVariations in co‐relatable parameters, such as pH, ORP and Fe (II) concentrations, indicated that these parameters significantly contributed to metal leaching. Operating the system under high and controlled ORPs is a faster and more efficient way to leach multi‐metals from WPCBs. © 2020 Society of Chemical Industry
Localized delivery of ibuprofen via a bilayer delivery system (BiLDS) for supraspinatus tendon healing in a rat model
Authors: Taylor Brittany L. , Kim Dong Hwa , Huegel Julianne , Raja Harina A. , Burkholder Sophie J. , Weiss Stephanie N. , Nuss Courtney A. , Soslowsky Louis J. , Mauck Robert L. , Kuntz Andrew F. , Bernstein Joseph 
Published: March 2020

AbstractThe high prevalence of tendon retear following rotator cuff repair motivates the development of new therapeutics to promote improved tendon healing. Controlled delivery of non‐steroidal anti‐inflammatory drugs to the repair site via an implanted scaffold is a promising option for modulating inflammation in the healing environment. Furthermore, biodegradable nanofibrous delivery systems offer an optimized architecture and surface area for cellular attachment, proliferation, and infiltration while releasing soluble factors to promote tendon regeneration. To this end, we developed a bilayer delivery system (BiLDS) for localized and controlled release of ibuprofen (IBP) to temporally mitigate inflammation and enhance tendon remodeling following surgical repair by promoting organized tissue formation. In vitro evaluation confirmed the delayed and sustained release of IBP from Labrafil‐modified poly(lactic‐co‐glycolic) acid microspheres within sintered poly(ε‐caprolactone) electrospun scaffolds. Biocompatibility of the BiLDS was demonstrated with primary Achilles tendon cells in vitro. Implantation of the IBP‐releasing BiLDS at the repair site in a rat rotator cuff injury and repair model led to decreased expression of proinflammatory cytokine, tumor necrotic factor‐α, and increased anti‐inflammatory cytokine, transforming growth factor‐β1. The BiLDS remained intact for mechanical reinforcement and recovered the tendon structural properties by 8 weeks. These results suggest the therapeutic potential of a novel biocompatible nanofibrous BiLDS for localized and tailored delivery of IBP to mitigate tendon inflammation and improve repair outcomes. Future studies are required to define the mechanical implications of an optimized BiLDS in a rat model beyond 8 weeks or in a larger animal model.
Meta‐Analysis of Associations Between Hypothalamic‐Pituitary‐Adrenal Axis Genes and Risk of Posttraumatic Stress Disorder
Authors: Sheerin Christina M. , Lind Mackenzie J. , Bountress Kaitlin E. , Marraccini Marisa E. , Amstadter Ananda B. , Bacanu Silviu‐Alin , Nugent Nicole R. 
Published: March 2020

AbstractThe hypothalamic‐pituitary‐adrenal (HPA) axis has been of interest in attempts to identify genetic vulnerability for posttraumatic stress disorder (PTSD). Although numerous HPA‐axis genes have been implicated in candidate gene studies, the findings are mixed and interpretation is limited by study design and methodological inconsistencies. To address these inconsistencies in the PTSD candidate gene literature, we conducted meta‐analyses of HPA‐related genes from both a traditional single nucleotide polymorphism (SNP)–level analysis and a gene‐level analysis, using novel methods aggregating markers in the same gene. Database searches (PubMed and PsycINFO) identified 24 unique articles examining six HPA‐axis genes in PTSD; analyses were conducted on four genes (ADCYAP1R1, CRHR1, FKBP5, NR3C1) that met study eligibility criteria (original research, human subjects, main effect association study of selected genes, PTSD as an outcome, trauma‐exposed control group) and had sufficient data and number of studies for use in meta‐analysis, within 20 unique articles. Findings from SNP‐level analyses indicated that two variants (rs9296158 in FKBP5 and rs258747 in NR3C1) were nominally associated with PTSD, ps = .001 and .001, respectively, following multiple testing correction. At the gene level, significant relations between PTSD and both NR3C1 and FKBP5 were detected and robust to sensitivity analyses. Although study limitations exist (e.g., varied outcomes, inability to test moderators), taken together, these results provide support for FKBP5 and NR3C1 in risk for PTSD. Overall, this work highlights the utility of meta‐analyses in resolving discrepancies in the literature and the value of adopting gene‐level approaches to investigate the etiology of PTSD.
Effects of Narrative Exposure Therapy on Posttraumatic Stress Disorder, Depression, and Insomnia in Traumatized North Korean Refugee Youth
Authors: Park Jinme K. , Park Jinah , Elbert Thomas , Kim Seog Ju 
Published: March 2020

AbstractRefugees affected by multiple traumatic stressors are at high risk for developing trauma‐related mental disorders, including posttraumatic stress disorder (PTSD), depression, and insomnia, which is sometimes overlooked. The present study examined the effectiveness of narrative exposure therapy (NET) on trauma‐related symptoms in a sample of North Korean refugee youth. We focused on sleep patterns in addition to changes in symptom severity for PTSD, depression, and internalizing and externalizing symptoms. North Korean refugee youth (N = 20) with PTSD were assigned to either an NET‐based treatment group or a control group, which consisted of treatment as usual (TAU). There were clinically significant reductions in PTSD, depression, and internalizing and externalizing symptoms for the NET group, Hedges’ g = 3.6, but not the TAU group. The change in diagnostic status for PTSD was more notable for participants in the NET group compared to the TAU group. Of note, NET also produced a significant improvement in insomnia symptoms and sleep quality, Hedges’ g = 2.1. The substantial recovery regarding overall posttraumatic symptoms in the NET group was observed 2 weeks after the end of treatment and remained stable at 6‐month follow‐up. The results of the present study suggest that NET may be a treatment option for traumatized North Korean refugee youth and may also be effective for the treatment of sleep problems that arise from traumatic experiences.
Positive Emotion Dysregulation Among Community Individuals: The Role of Trauma Exposure and Posttraumatic Stress Disorder
Authors: Weiss Nicole H. , Contractor Ateka A. , Forkus Shannon R. , Goncharenko Svetlana , Raudales Alexa M. 
Published: March 2020

AbstractExisting literature has provided support for an association between posttraumatic stress disorder (PTSD) and emotion dysregulation. However, few studies have examined the relation between PTSD and emotion dysregulation that stems from positive emotions. Moreover, the role of trauma exposure, per se, on positive emotion dysregulation is unknown. Addressing these limitations, the current study compared levels of positive emotion dysregulation among (a) individuals without trauma exposure, (b) trauma‐exposed individuals without probable PTSD, and (c) trauma‐exposed individuals with probable PTSD. Participants were 400 community‐dwelling individuals (M age = 43.76 years, 68.6% female; 24.2% Asian, 23.7% Black, 24.5% Hispanic, 27.6% White). Lower levels of positive emotion dysregulation were found among trauma‐exposed participants without probable PTSD compared to trauma‐exposed participants with probable PTSD, ds = 0.66–0.73, and unexposed participants, ds = 0.58–0.64. The present findings suggest the potential protective role of low levels of positive emotion dysregulation following trauma exposure. If replicated in longitudinal studies, these results may indicate the utility of enhancing skills for regulating positive emotions among individuals at risk for trauma exposure.