bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Catalytically Active Zinc Oxide−Carbon Nanotube Composite on Sensitive Assay of Desloratadine Metabolite
Authors: Ozturk Kubra , Bakirhan Nurgul K. , Ozkan Sibel A. , Uslu Bengi 
Published: August 2019

AbstractDesloratadine is one of the most effective second‐generation antihistamines and the electrochemical behavior of the active agent of desloratadine was investigated with a new nanosensor designed with the addition of zinc oxide and multiwalled carbon nanotube (ZnO : MWCNT) mixture on glassy carbon (GCE). By investigating and using cyclic, differential pulse and square wave voltammetry techniques with ZnO : MWCNT/GCE, it is planned to obtain information about quantification and mechanism of desloratadine. The efficiency of experimental parameters such as pH, scan rate, accumulation potential and time on the anodic response of desloratadine were studied. Differential pulse voltammetry was selected as assay method and under developed method and optimized conditions, the current showed linear dependence with concentration in the range between 2×10−8 and 8×10−6 M in pH 5.5 acetate buffer. The achieved limits of detection (LOD) and quantification (LOQ) are 0.769 nM and 2.56 nM respectively. Applicability of the methods was demonstrated by their implementation in pharmaceutical dosage forms of desloratadine and the accuracy, precision, selectivity, sensitivity, intra‐day and day‐to‐day reproducibility of the methods were clearly explored. Finally, this sensor was successfully applied on real sample as a selective, simple, reproducible, repeatable an electrochemical sensor.
Mesopore‐controllable Carbon Aerogel and their Highly Loaded PtRu Anode Electrocatalyst for DMFC Applications
Authors: Bong Sungyool , Han Donghoon 
Published: August 2019

AbstractCatalyst loading and layer thickness are crucial factors to enhance the cell performance and to reduce cost of membrane electrode assemblies (MEAs). Outstanding properties, such as large surface area to disperse metal nanoparticles and sufficient pore volume and size, is needed in utilization of fuel cell. Carbon aerogels are one of the good candidates that meets the above conditions. Those are synthesized by polycondensation reaction of resorcinol and formaldehyde (RF) polymer, supercritical drying to keep pore skeleton structure caused by capillary force and calcination of RF polymer in nitrogen atmosphere to be controllable meso pore (2∼43 nm) as role of support for electric conductor and dispersion of metal nanoparticles. In order to utilization of anode catalyst in direct methanol fuel cell, highly loaded (80 weight percent) platinum and ruthenium onto carbon aerogel are synthesized by Bönnemann colloid method. The single cell test of carbon aerogel supported PtRu anode catalyst is performed and over 40 nm pore sized‐catalysts are the best performance due to sufficient surface area to anchor uniform and small metal nanoparticles and good pathway to drive fuel and outgas even though PtRu nanoparticles are anchored on the outer surface of carbons.
Simultaneous Electroanalysis of Guaiacol and its Analogs Based on their Differential Complexation with α‐Cyclodextrin on Nafion Modified Boron‐doped Diamond Electrode
Authors: Hayes Phyllis E. , Glennon Jeremy D. , Buzid Alyah , Luong John H. T. 
Published: August 2019

AbstractGuaiacol and its analogs, a distinct flavor in whiskey, foods, and beverages, display different inclusion complexes with α‐Cyclodextrin (α‐CD) and can be detected on a Nafion modified boron‐doped diamond (BDD) electrode. The stable Nafion layer preconcentrates the analyte‐α‐CD complexes prior to electroanalysis by square wave voltammetry (SWV) to enhance detection sensitivities. This sensing mode together with peak deconvolution successfully distinguishes between guaiacol, 4‐ethylguaiacol (4‐EG), three cresol isomers, and phenols in a popular whiskey brand. The results obtained are corroborated by high‐performance liquid chromatography (HPLC). Anodic oxidation at + 2 V in phosphate buffer, pH 7 is proven as an effective method to renew the electrode surface after its exposure to the guaiacols. This robust approach circumvents several drawbacks associated with the use of enzymes and nanomaterials for the analysis of such analytes as reported in the literature.
An Electrochemical Biosensor Platform for Testing of Dehydroepiandrosterone 3‐Sulfate (DHEA−S) as a Model for Doping Materials
Authors: Balaban Simge , Durmus Ceren , Celikbas Eda , Gumus Zinar Pinar , Timur Suna 
Published: August 2019

AbstractEndogenous steroids such as dehydroepiandrosterone (DHEA) and dehydroepiandrosterone 3‐sulfate (DHEA−S) have commonly used as doping materials by athletes and to date novel techniques are needed for detection of these molecules. In this study, antibody‐based electrochemical biosensor has developed for testing level of the DHEA−S. For this aim, gold surfaces were initially modified with cysteamine (Cys) and then, DHEA−S antibody was immobilized on the surface via glutaraldehyde (GA) as a crosslinking agent. The stepwise modification of electrode surface was monitored by using various electrochemical techniques such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Linear range was determined as 2.5–100 ng/mL DHEA−S using differential pulse voltammetry (DPV) technique, as well. Moreover, repeatability (±S.D.), coefficient of variation (%) and limit of detection (LOD) values were calculated as 0.033, 1.030 and 3.971, respectively. Also, DHEA−S in synthetic serum and urine samples were successfully determined with standard addition method and confirmation analysis were performed with liquid chromatography quadrupole‐time of flight mass spectrometry (LC‐QTOF/MS) system. The selectivity was studied with the addition of some interfering molecules (testosterone, bovine serum albumin (BSA), cholesterol, uric acid, lactic acid, codein (COD), ascorbic acid, DHEA). Consequently, this work is proposed as practical, innovative and cost‐effective technique that can be easily adapted for the miniaturized form for the analysis of other doping substances as well as DHEA−S for the future works.
Evaporation of Electrolyte during SVET Measurements: The Scale of the Problem and the Solutions
Authors: Bouali A. C. , Bastos A. C. , Lamaka S. V. , Serdechnova M. , Ferreira M. G. S. , Zheludkevich M. L. 
Published: August 2019

AbstractThe objective of this work is to investigate the scale of the effect of spontaneous solution evaporation during SVET (Scanning Vibrating Electrode Technique) measurements and demonstrate how it biases the final results. When SVET maps are continuously acquired for more than several hours, the measured currents are smaller than expected. This is attributed to solvent (typically water) evaporation which leads to an increase in solution conductivity over time. If this is not considered when converting the measured potential differences into the local current densities, the SVET results display currents smaller than the true ones. Here, this effect is studied with a platinum disk electrode as source of a constant current and a model corroding system consisting of the AA2024/CFRP galvanic couple. Corrective actions are proposed to mitigate the problem, either in the experimental set‐up or as numerical correction.
Perspectives of surface plasmon resonance sensors for optimized biogas methanation
Authors: Lamb Jacob J. , Bernard Olivier , Sarker Shiplu , Lien Kristian M. , Hjelme Dag Roar 
Published: August 2019

AbstractBiogas production is becoming significantly viable as an energy source for replacing fossil‐based fuels. The further development of the biogas production process could lead to significant improvements in its potential. Wastewater treatment currently accounts for 3% of the electrical energy load in developed countries, while it could be developed to provide a source of nitrogen and phosphorus, in addition to energy. The improvement of anaerobic digestion (AD) detection technologies is the cornerstone to reach higher methane productivities and develop fully automatized processes to decrease operational costs. New sensors are requested to automatically obtain a better interpretation of the complex and dynamical internal reactor environment. This will require detailed systematic detection in order to realize a near‐optimal production process. In this review, optical fiber‐based sensors will be discussed to assess their potential for use in AD. There is currently a disparity between the complexity of AD, and online detection. By improving the durability, sensitivity, and cost of dissolved H2 (as well as H2S, acetic acid, ammonia, and methane) sensor technology, further understanding of the AD process may allow the prevention of process failure. The emergence of surface plasmon resonance (SPR) sensing with optical fibers coupled with the H2‐sensitive metal palladium, allows detection of dissolved hydrogen in liquid. By implementing these SPR sensors into AD, improvements to the biogas production process, even at small scales, may be achieved by guiding the process in the optimum direction, avoiding the collapse of the biological process. This review intends to assess the feasibility of online, cost‐effective, rapid, and efficient detection of dissolved H2, as well as briefly assessing H2S, acetic acid, ammonia, and methane in AD by SPR.
MAOA‐VNTR genotype affects structural and functional connectivity in distributed brain networks
Authors: Harneit Anais , Braun Urs , Geiger Lena S. , Zang Zhenxiang , Hakobjan Marina , van Donkelaar Marjolein M. J. , Schweiger Janina I. , Schwarz Kristina , Gan Gabriela , Erk Susanne , Heinz Andreas , Romanczuk‐Seiferth Nina , Witt Stephanie , Rietschel Marcella , Walter Henrik , Franke Barbara , Meyer‐Lindenberg Andreas , Tost Heike 
Published: August 2019

AbstractPrevious studies have linked the low expression variant of a variable number of tandem repeat polymorphism in the monoamine oxidase A gene (MAOA‐L) to the risk for impulsivity and aggression, brain developmental abnormalities, altered cortico‐limbic circuit function, and an exaggerated neural serotonergic tone. However, the neurobiological effects of this variant on human brain network architecture are incompletely understood. We studied healthy individuals and used multimodal neuroimaging (sample size range: 219–284 across modalities) and network‐based statistics (NBS) to probe the specificity of MAOA‐L‐related connectomic alterations to cortical‐limbic circuits and the emotion processing domain. We assessed the spatial distribution of affected links across several neuroimaging tasks and data modalities to identify potential alterations in network architecture. Our results revealed a distributed network of node links with a significantly increased connectivity in MAOA‐L carriers compared to the carriers of the high expression (H) variant. The hyperconnectivity phenotype primarily consisted of between‐lobe (“anisocoupled”) network links and showed a pronounced involvement of frontal‐temporal connections. Hyperconnectivity was observed across functional magnetic resonance imaging (fMRI) of implicit emotion processing (pFWE = .037), resting‐state fMRI (pFWE = .022), and diffusion tensor imaging (pFWE = .044) data, while no effects were seen in fMRI data of another cognitive domain, that is, spatial working memory (pFWE = .540). These observations are in line with prior research on the MAOA‐L variant and complement these existing data by novel insights into the specificity and spatial distribution of the neurogenetic effects. Our work highlights the value of multimodal network connectomic approaches for imaging genetics.
Employee share ownership, training, and early promotion policy as a bundle in enhancing labor productivity: A test of the three‐way interaction effect
Authors: Yoon Yeongjoon , Sengupta Sukanya 
Published: August 2019

AbstractThe three‐way interaction effect of (broad‐based) employee share ownership (ESO), training, and early promotion policy on labor productivity was examined in a longitudinal sample of 614 organizations (1,605 organization‐year data points) in Korea. The ESO–productivity relationship was positive only when the investment in training was high and the opportunity for early promotion was present. However, we found no evidence for the two‐way interaction effects of ESO and training and ESO and early promotion policy on labor productivity. The results are in alignment with the emergent view that the productivity benefits of ESO can be better realized when ESO coexists with a bundle of complementary human resource management (HRM) practices. Thus, this study meaningfully extends the contingency perspective and related studies in the ESO literature, which tend to examine the productivity effect of ESO in isolation or in conjunction with a single HRM practice.
Concentration‐dependent cellular behavior and osteogenic differentiation effect induced in bone marrow mesenchymal stem cells treated with magnetic graphene oxide
Authors: He Yi , Li Yiming , Chen Guanhui , Wei Changbo , Zhang Xiliu , Zeng Binghui , Yi Chen , Wang Chao , Yu Dongsheng 
Published: August 2019

AbstractThe scaffold‐free cell sheet plays an important role in stem‐cell‐based regeneration. Graphene oxide (GO) endows nanoparticles (NPs) with special characteristics and therefore has attracted increasing attention in recent years. However, the existence of toxicity in GO and its derivatives limits their ability to promote osteogenic differentiation. Magnetic graphene oxide (MGO), a novel combination of Fe3O4 and GO with diverse unique properties, has not been studied in bone tissue engineering. In this study, MGO was fabricated, and the previously undiscovered relationships—including cellular behavior and the effects of osteogenic differentiation and related mechanisms of MGO in rat bone‐marrow‐derived mesenchymal stem cells (BMSCs)—were investigated for the first time. Here, we found that MGO was not only biocompatible at low concentrations, but also could significantly accelerate osteogenic differentiation in BMSCs. Both the cellular behavior and bone‐formation differentiation in BMSCs treated with MGO showed concentration‐dependent characteristics. In addition, the regulation of osteogenic differentiation in BMSCs treated with MGO might be involved with the Wnt/β‐catenin and BMP signaling pathways. Furthermore, MGO demonstrated a better ability for osteogenic differentiation in BMSCs than did GO. The current work indicated a significant use for MGO nanocomposite scaffolds in biocompatibility and bone regeneration, which could provide new insight into bone regeneration in the future.
Photocatalytic disinfection and purification of water employing reduced graphene oxide/TiO2 composites
Authors: Berberidou Chrysanthi , Kyzas George Z , Paspaltsis Ioannis , Sklaviadis Theodoros , Poulios Ioannis 
Published: August 2019

AbstractBACKGROUNDRecombination of photogenerated carriers in titanium dioxide (TiO2)‐mediated semiconducting photocatalysis is considered to be the principal obstacle in its unlimited exploitation in practical applications. Hybridization of TiO2 with graphene‐based materials appears to be a highly promising alternative. In this context, reduced graphene oxide (rGO)/TiO2 composites were prepared using a simple ultrasonically assisted route under mild reaction conditions.RESULTSThe as‐prepared composites were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectrometry (EDS), Fourier‐transform infrared spectroscopy (FTIR) and nitrogen adsorption–desorption isotherms. Photocatalytic efficiencies of the as‐prepared composites were evaluated employing the pesticide clopyralid as a model pollutant. Initial degradation and mineralization rates obtained in the presence of the as‐prepared composites were, in all cases, higher than the one obtained in the presence of the bare TiO2, with 5% rGO/TiO2 achieving the highest r0 and rDOC values. The as‐prepared composites also were evaluated based on their potential to inactivate bacterial endospores of the Bacillus stearothermophilus species, well‐known for their extraordinary resistance to most inactivation processes. Prevalence of 5% rGO/TiO2 in the inactivation of B. stearothermophilus among all as‐prepared materials was evident, accomplished within 120 min of UV‐A illumination. Real‐time PCR experiments enabled the detection of genomic DNA released during photocatalytic oxidation, in the presence of 5% rGO/TiO2 and UV‐A, suggesting lysis of the outer and inner spore coat caused by the generated ROS.CONCLUSIONSThese findings demonstrate the potential of rGO, a low‐cost, nontoxic material to serve as a reliable alternative in the enhancement of TiO2 photocatalytic efficiency in water processing applications. © 2019 Society of Chemical Industry
Analysis of color shift on butterfly wings by Fourier transform of images from atomic force microscopy
Authors: Kaspar Pavel , Sobola Dinara , Sedlák Petr , Holcman Vladimír , Grmela Lubomír 
Published: August 2019

AbstractButterfly wings have complex structure lending it several interesting properties. Coloration of the wing is one of the first things to encounter and the overall visual effect is in fact influenced by several factors. Chemical pigments set the base color of the wing, topographical structures on the wing scales cause color shift by interference and their arrangement into diffraction grating causes iridescence. The thin film interference can be attributed to microscopic ridges covering wing scales. Observation and calculation of the color shift on wings of Euploea mulciber species using Fourier transform of images obtained by atomic force microscopy is the focus of this article.
Synthesis and Pharmacological Evaluation of 4‐Aryloxyquinazoline Derivatives as Potential Cytotoxic Agents
Authors: Malhotra Anjleena , Kaur Tejinder , Bansal Ranju 
Published: August 2019

In the present study, novel 4‐aryloxyquinazoline derivatives were synthesized and screened for in vitro cytotoxicity on human cancer cell lines at 10 μM. Some of the synthesized compounds displayed moderate to significant and selective cytotoxic activity against various leukemia, melanoma, ovarian, breast, and colon cancer cell lines. (E)‐3‐(3,4‐Dimethoxyphenyl)‐1‐(4‐(quinazolin‐4‐yloxy)phenyl)prop‐2‐en‐1‐one (9b) was the most potent compound among all with an average growth inhibition of 70% against leukemia cancer cell lines. The compound also produced strong inhibition (75%) of colon cancer cell lines with 42.58% lethality of HCT‐116 cell line.
HIV‐1 DNA decay is faster in children who initiate ART shortly after birth than later
Authors: Veldsman Kirsten A , Janse van Rensburg Anita , Isaacs Shahieda , Naidoo Shalena , Laughton Barbara , Lombard Carl , Cotton Mark F , Mellors John W , van Zyl Gert U 
Published: August 2019

AbstractIntroductionThere is limited data in children on whether persistence of HIV‐1 infected cells is affected by age at initiating antiretroviral therapy (ART), its duration or any subsequent ART interruption. We therefore investigated the effects of both age of ART initiation and duration of ART interruption on HIV‐1 DNA decay in children.MethodsWe investigated HIV‐1 DNA decay in three groups of children on ART: Group‐1 (n = 7) started uninterrupted ART within eight days of life; Group‐2 (n = 8) started uninterrupted ART at a median of five months of age; and Group‐3 (n = 23) started ART at a median age of 1.8 months for either 40 or 96 weeks, then interrupted ART (median of seven months), and restarted ART based on CD4 count and clinical criteria. Total HIV‐1 DNA was assayed using a sensitive HIV‐1 subtype C‐adapted quantitative PCR for integrase. The duration of ART was square root transformed to fit the observed slowing of HIV‐1 DNA decay rate. For each group, point estimates for decay rates were determined after six months of continuous suppressive ART in groups 1 and 2 or six months after restarting ART in Group‐3. Groups‐2 and 3 were combined using a mixed effect regression model to investigate covariates of HIV‐1 DNA decay rate.Results and DiscussionAt six months of continuous suppressive ART, the HIV‐1 DNA t½ (95% CI) was shorter in Group‐1 (n = 7): 2.7 months (2.1 to 3.8), than 9.2 months (7.4 to 12.1) in Group‐2 (n = 8); and 9.6 months (7.6 to 12.6) in Group‐3 (n = 23) (p < 0.01). In multivariable analyses, HIV‐1 DNA before treatment (p < 0.001) and the change in HIV‐1 DNA during interruption (p < 0.01) were independent predictors of slower HIV‐1 DNA decay.ConclusionsThese data suggest that ART initiation within the first week of life can reduce the persistence of long‐lived infected cells. Delaying ART is associated with slower decay of infected cells.
Spectral Signatures in the Different Layers of the Human Eyelid by Photoacoustic Imaging
Authors: Dahlstrand Ulf , Sheikh Rafi , Berggren Johanna , Hult Jenny , Albinsson John , Cinthio Magnus , Malmsjö Malin 
Published: August 2019

Background and ObjectivesThe eyelids are susceptible to a number of skin cancers, which are challenging to excise radically without sacrificing excessive healthy tissue. Photoacoustic (PA) imaging is an emerging non‐invasive biomedical imaging modality that could potentially be used for intraoperative micrographic control of the surgical margins of eyelid tumors. In this study, non‐cancerous human eyelid tissue was characterized using PA as a first step in the development of this technique.Study Design/Materials and MethodsTwelve full‐thickness samples from nine patients were analyzed ex vivo using PA imaging. Two‐dimensional PA images were acquired using 59 wavelengths in the range of 680–970 nm to obtain the spectral signatures of the skin, orbicularis oculi muscle, and the tarsal plate. Three‐dimensional images were obtained by scanning the tissues using a linear stepping motor. Spectral unmixing was performed to visualize the chromophore distribution.ResultsThe resulting PA spectra could be used to differentiate between the orbicularis oculi muscle and the other two structures (P < 0.05). The signals from the skin and the tarsal plate were more similar in appearance, probably due to similarities in their molecular composition. Spectral unmixing provided a clear visualization of the overall architecture of the eyelids.ConclusionsPA imaging can be used to differentiate between the orbicularis oculi muscle and the eyelid skin and tarsal plate. The main structures of human eyelids could be visualized in three dimensions using PA imaging. This technique could potentially be used to examine eyelid tumors intraoperatively in the future. However, further studies on tumors in vivo are needed before considering such clinical use. Lasers Surg Med. © 2019 Wiley Periodicals, Inc.