bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective Detection of Dopamine in the Presence of Ascorbic and Uric Acids through its Covalent Immobilization on Gold Mercaptopropionic Acid Self‐assembled Monolayer
Authors: Karimi Shervedani Reza , Bahrani Sonia , Samiei Foroushani Marzieh , Momenbeik Fariborz 
Published: August 2016

AbstractA simple, stable and recoverable sensor is developed based on selective and covalent immobilization of dopamine (DA) on the gold (Au) electrode modified by mercaptopropionic acid (MPA) self‐assembled monolayers and then, activated with 1‐ethyl‐3(3‐(dimethylamino)propyl)‐carbodiimide hydrochloride (EDC)/n‐hydroxysuccinimide (NHS) activators. Fabrication steps and analytical application of this modified electrode toward quantitative determination of DA in the presence of ascorbic and uric acids are verified by cyclic and differential pulse voltammetry (CV and DPV) methods in the absence of any redox probe. The oxidation peak current of adsorbed DA changed linearly with the concentration of DA in the range of 0.5 to 600.0 μM with a detection limit of 0.064 μM, and the RSDs varied from 1.4 to 3.5 % for n=3 at each point. Finally, the fabricated sensor is used successfully for electroanalytical determination of DA in human blood plasma and pharmaceutical injection real samples.
Ionic Liquid and Nitrogen Doped Carbon Nanotubes Composite Material for Sensitive and Selective Detection of Dopamine
Authors: Joshi Anju , Chavan Santosh N. , Mandal Debaprasad , Nagaiah Tharamani C. 
Published: August 2016

AbstractThe composites of IL (BmimBF4) and various nitrogen doped carbon nanotubes (NCNTs) synthesized by post treatment under NH3 at different temperatures have been explored as a novel composite material for the sensitive and selective detection of dopamine (DA). The electrocatalytic activity of these various NCNTs‐IL composites for the detection of DA was examined by voltammetric and rotating disc electrode (RDE) measurements. These novel NCNTs‐IL composites exhibit a superior sensitivity and selectivity towards the oxidation of DA in presence of higher concentration of AA (500 µM). A linear response between the peak current and the concentration of DA was found to be in the concentration range of 0.001 µM–40 µM and 0.001 µM–10 µM for individual and even in presence of 500 µM of AA respectively.
Potential‐modulated Electrocapacitive Properties of Soft Microstructured Polypyrrole
Authors: Vagin Mikhail Yu. , Wannapob Rodtichoti , Liu Yu , Mak Wing Cheung 
Published: August 2016

AbstractMicrostructured materials are becoming important for high performance electrochemical device especially for energy storage due to their advantageous diffusion and flux properties. Utilizing a rationally designed hollow structured polypyrrole microparticles (PPyMPs) with controllable wall thicknesses of ∼110 to 340 nm, we observed a significant morphological effect on electrocapacitive kinetics of the PPyMPs modulated by the voltammetric potential window and scan rate. The thin‐hollow architecture of PPyMPs revealed significant enhancement of charge storage performance (up to 447 %), high retention at high scan rate and faster charge/discharge kinetics compared to the thick‐hollow PPyMPs due to the larger accessible surface area and decrease of diffusion length. These findings demonstrated the electrocapacitive kinetics performance of microstructured soft materials related to morphological effect modulated by operational conditions. Our study provides new insight on electrochemistry of soft electrode materials with controlled nanostructured morphology for understanding the mechanism of charge insertion and mass diffusion for the future development of high performance porous electrode material.
A Simple Flow Amperometric Electrochemical Biosensor Based on Chitosan Scaffolds and Gold Nanowires Modified on a Glassy Carbon Electrode for Detection of Glutamate in Food Products
Authors: Kitikul Jiraporn , Satienperakul Sakchai , Preechaworapun Anchana , Pookmanee Pusit , Tangkuaram Tanin 
Published: August 2016

AbstractA glutamate biosensor based on cross‐linked glutamate oxidase with chitosan (CHIT) on a carbon nanotube (CNT)‐modified gold nanowire (AuNW) was constructed and applied in a flow injection analysis (FIA) system. The AuNW was produced using an alumina template membrane and characterized using scanning electron microscopy (SEM) with a 120‐nm diameter. The CHIT cross‐linked CNT slurry was mixed with AuNW and cast on the surface of a glassy carbon electrode (GCE), followed by immobilization with the glutamate oxidase. Optimization of the experimental parameters, including the applied potential, enzyme loading, flow rate, type of buffer and pH, resulted in values of 0.7 V, 30 μL, 1.0 mL min−1, phosphate buffer, and pH 7.4, respectively. The analytical working curve was linear in the ranges from 10 to 100 (R2=0.9981) and 100 to 20,000 μM glutamate (R2=0.9821) with a low detection limit of 1.2 μM (S/N=3). A glutamate biosensor with an FIA system was used to determine glutamate in samples of Thai commercial food products.
Oxygen Electroreduction versus Bioelectroreduction: Direct Electron Transfer Approach
Authors: Shleev Sergey , Andoralov Viktor , Pankratov Dmitry , Falk Magnus , Aleksejeva Olga , Blum Zoltan 
Published: August 2016

AbstractBeing inspired by a very recent review entitled: “Electrocatalysis and bioelectrocatalysis – Distinction without a difference” and following the general approach employed by Prof. Dr. Schuhmann, in the current work we point to the similarities and differences between oxygen electroreduction and bioelectroreduction processes. To additionally distinct our paper from the recent review we touch on different bioelements, such as redox proteins and living cells, but we still keep a special emphasis on oxidoreductases, biocatalysts par excellence. Moreover, we also exclusively focus on oxygen electroreduction based on direct electron transfer reactions. On the one hand, we corroborate the previously made conclusion regarding intrinsically high activity of the active sites of biological catalysts, especially redox enzymes, which results in mass transfer and heterogeneous electron transfer limited currents from oxygen reducing bioelectrodes. On the other hand, we disagree with the statements regarding the exceptionality of precious metal catalysts, and the notion of a huge trade‐off between high activity and stability of non‐precious metal catalysts and bioelements. We show that the activity and stability of noble metal based cathodes is very far from perfect, especially when these electrodes operate in complex electrolytes, such as physiological fluids, e.g. human blood.
Electrochemical Reduction and Intramolecular Electron Communication of Nitro Substituted Thiacalix[4]arenes
Authors: Liška Alan , Lhoták Pavel , Ludvík Jiří 
Published: August 2016

AbstractThis contribution is focused on the question, what is the influence of the sulphur bridging units in thiacalix[4]arenes on their electrochemical response. For this reason, two series of oligonitro thiacalix[4]arenes were investigated, where the “classic” methylene groups are replaced by the sulphur bridge. The reduction pattern of p‐tetranitro‐1,3‐alt‐thiacalix[4]arenes (2+2+12 electrons) resembles that of the p‐tetranitro‐cone‐calix[4]arenes and refers to the presence of two different couples of non‐interacting nitro groups in the molecule. In contrast, m‐oligonitro‐1,3‐alt‐thiacalix[4]arenes exhibit a mutual intramolecular communication between multiple redox centers (nitro groups) due to the combination of two circumstances: nitro groups in the m‐positions towards the lower rim are in fact in para‐ and/or ortho position towards the thia‐bridges enabling thus 1,2‐ and 1,4‐quinoid resonance structure, and larger sulphur bridging atom forms two adjacent C‐S bonds, which are able to exhibit a hyperconjugative effect. In any case, the intramolecular electron communication takes place via the skeleton, not through space. Consequently, the substituent (inductive, mesomeric) and charge effects are observable, additive and partly quantifiable. Classic polarography proved to be the optimal technique for such investigations.
A Facile Synthesis of Cd(OH)2‐rGO Nanocomposites for the Practical Electrochemical Detection of Acetaminophen
Authors: Sakthivel Mani , Sivakumar Mani , Chen Shen‐Ming , Hou Yu‐Shen , Veeramani Vediyappan , Madhu Rajesh , Miyamoto Nobuyoshi 
Published: August 2016

AbstractHerein, we report the preparation of nanorods‐like Cd(OH)2‐rGO nanocomposites via using a simple co‐precipitation method. The as‐prepared Cd(OH)2‐rGO materials were characterized by a variety of analytical and spectroscopy techniques such as scanning electron microscope (SEM), elemental analysis (EDX), X‐ray diffraction (XRD), and Raman spectroscopy. Interestingly, Cd(OH)2‐rGO modified glassy carbon electrode (GCE) employed for the electrochemical detection of acetaminophen (AP) sensor for first time by using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The AP sensor exhibited an ultra‐high sensitivity of 24.452 µA µM−1 cm−2 and a low detection limit 0.08 µM with wider linear ranges from 0.1 to 102 µM. Notably, the obtained analytical parameters of the AP sensor using nanorods‐like Cd(OH)2‐rGO modified GCE is superior than several rGO based nanocomposites suggesting more suitable for several practical pharmaceutical applications.
Assessment of the Production of Value‐Added Chemical Compounds from Sewage Sludge Pyrolysis Liquids
Authors: Fonts Isabel , Navarro‐Puyuelo Andrea , Ruiz‐Gómez Nadia , Atienza‐Martínez María , Wisniewski Alberto , Gea Gloria 
Published: August 2016

AbstractA procedure to analyze sewage sludge (SS) pyrolysis liquids based on solvent fractionation has been developed. Pyrolysis liquids are separated into three different fractions: heptane soluble (Hep‐sol), dichloromethane soluble (DCM‐sol), and hydrochloric acid soluble (HCl‐sol). Diverse techniques (GC‐MS, UPLC‐TOF‐MS) were employed to qualitatively and quantitatively analyze liquid fractions to assess the potential production of value‐added chemicals. Aliphatic hydrocarbons, aliphatic nitriles, and steroids were mostly separated in the Hep‐sol fraction, phenols and fatty acids in the DCM‐sol fraction, and carboxylic acids and amides in the HCl‐sol fraction. The largest production was obtained for ammonia (10–14 kg per tonne of SS) and α‐olefins (8–9 kg per tonne of SS). The potential production of some of these value‐added chemicals from SS pyrolysis liquid was compared with their current European production. In the case of α‐olefins, 16 % of their European production could be achieved by SS pyrolysis.
Ecotoxicological assessment of glyphosate-based herbicides: Effects on different organisms
Authors: de Brito Rodrigues Laís , de Oliveira Rhaul , Abe Flávia Renata , Brito Lara Barroso , Moura Diego Sousa , Valadares Marize Campos , Grisolia Cesar Koppe , de Oliveira Danielle Palma , de Oliveira Gisele Augusto Rodrigues 
Published: August 2016

Abstract

Glyphosate-based herbicides are the most commonly used worldwide because they are effective and relatively nontoxic to nontarget species. Unlimited and uncontrolled use of such pesticides can have serious consequences for human health and ecological balance. The present study evaluated the acute toxicity and genotoxicity of 2 glyphosate-based formulations, Roundup Original (Roundup) and Glyphosate AKB 480 (AKB), on different organisms: cucumber (Cucumis sativus), lettuce (Lactuca sativa), and tomato (Lycopersicon esculentum) seeds, and microcrustacean Artemia salina and zebrafish (Danio rerio) early life stages. For the germination endpoint, only L. esculentum presented significant sensitivity to AKB and L. sativa to Roundup, whereas both formulations significantly inhibited the root growth of all species tested. Both AKB and Roundup induced significant toxicity to A. salina; both are classified as category 3, which indicates a hazard for the aquatic environment, according to criteria of the Globally Harmonized Classification System. However, Roundup was more toxic than AKB, with 48-h median lethal concentration (LC50) values of 14.19 mg/L and 37.53 mg/L, respectively. For the embryo–larval toxicity test, Roundup proved more toxic than AKB for the mortality endpoint (96-h LC50 values of 10.17 mg/L and 27.13 mg/L, respectively), whereas for the hatching parameter, AKB was more toxic than Roundup. No significant genotoxicity to zebrafish larvae was found. We concluded that AKB and Roundup glyphosate-based formulations are phytotoxic and induce toxic effects in nontarget organisms such as A. salina and zebrafish early life stages. Environ Toxicol Chem 2017;36:1755–1763. © 2016 SETAC
Phenylphosphinic acid‐catalyzed synthesis of 6‐unsubstituted dihydropyrimidinones under solvent‐free conditions
Authors: Alinezhad Heshmatollah , Tajbakhsh Mahmood , Zare Mahboobeh , Mousavi Mahboobeh 
Published: August 2016

AbstractPhenylphosphinic acid is found to catalyze the three‐component condensation of an aldehyde, enaminone, and urea or thiourea to afford the corresponding 6‐unsubstituted dihydropyrimidinones in high to excellent yields. This methodology is simple and fast synthetic route for the preparation of interesting class of heterocycles.
Elevated cholesterol levels have a poor prognosis in a cholestasis scenario
Authors: Nuño‐Lámbarri Natalia , Barbero‐Becerra Varenka J , Uribe Misael , Chávez‐Tapia Norberto C 
Published: August 2016

AbstractCholestasis results from defective bile flow through the biliary ducts leading to the accumulation of bile acids (BAs) in hepatocytes and serum. It has been seen that cholestasis is associated with hypercholesterolemia, which is a prerequisite for gallstone formation and primary biliary cirrhosis, being some of the most common gastrointestinal disorders in Western societies. Cytotoxic BAs induce proinflammatory mediators, oxidative stress, and apoptosis in hepatocytes, whereas cytoprotective BAs prevent them; they can also modify the plasmatic membrane structure of cells or mitochondrial outer membrane properties as well as the distribution of cholesterol, altering various proteins involved in BAs homeostasis.
A homogenized long‐term temperature record for the Western Cape Province in South Africa: 1916–2013
Authors: Lakhraj‐Govender Rakhee , Grab Stefan , Ndebele Nothabo E. 
Published: August 2016

ABSTRACTTo establish precise climate trend analyses, highly reliable and accurate homogenous historical climate data are required. To this end, we undertake a robust quality control and homogenization process of daily Tmax and Tmin data (1916–2013) for the Western Cape Province, South Africa, using RClimDex, ProClimDB and Anclim software. Inhomogeneities were detected using the pairwise method in AnClim, suggesting possible artificial shifts in the time series. The adjustment of time series utilized ProClimDB software to create reference series using highly correlated or nearest neighbour stations. Given few available long‐term data sets, the study is limited to eight suitable stations. The modified Mann Kendall test in XLSTAT 2015 software identified annual and seasonal trends in the newly homogenized monthly Tmax and Tmin data. Annual Tmax and Tmin adjusted data over the Western Cape region indicate statistically significant increasing temperature trends over the period 1916–2013, with the exception of an insignificant decreasing Tmax trend at Cape St Blaize. A statistically significant increasing trend (0.13 °C/decade) for all stations used in this study is recorded for the common period 1937–2001. The seasonal trends also support significant increasing trends, with the exception of Tmax trends for summer (−0.03 °C/decade) and autumn (0 °C/decade) at Kirstenbosch.
Bidirectional raster scanning to increase time for vector writing in avionics see‐through displays
Authors: Moddal Amandeep , Karar Vinod , Agrawal Divya , Rawat Mohit 
Published: August 2016

AbstractSee‐through displays (STD) like head‐up displays (HUD) play major role in providing aircraft data to pilot through a visual interface. The data is displayed in form of symbology in pilot's line of sight using vector scanning technique and is deciphered to get flight and mission information. Contrast ratio required to see against bright sunlight at high altitudes is given only by luminance of cathode ray tube (CRT). Therefore, CRT is still used as display source in avionic HUDs, although other devices are also being explored for these applications. Aircraft's night mode operation requires raster display of external scene information along with vector data display due to low visibility during night. It reduces time available for writing vector data during night mode resulting in reduced symbology. Conventionally used raster scanning methods are unidirectional scanning methods. Bidirectional raster scanning (BRS) is an unconventional approach which scans display screen from both directions. In present work, an algorithm for BRS has been developed in VHDL providing more time for vector writing by increasing vertical retrace period (VRP) of raster scanning. Functional verification of design has been performed by simulations carried out through test‐bench and VRP is increased to 5.8304 ms from conventional 1.2800 ms per field.
CGBVS‐DNN: Prediction of Compound‐protein Interactions Based on Deep Learning
Authors: Hamanaka Masatoshi , Taneishi Kei , Iwata Hiroaki , Ye Jun , Pei Jianguo , Hou Jinlong , Okuno Yasushi 
Published: August 2016

AbstractComputational prediction of compound‐protein interactions (CPIs) is of great importance for drug design as the first step in in‐silico screening. We previously proposed chemical genomics‐based virtual screening (CGBVS), which predicts CPIs by using a support vector machine (SVM). However, the CGBVS has problems when training using more than a million datasets of CPIs since SVMs require an exponential increase in the calculation time and computer memory. To solve this problem, we propose the CGBVS‐DNN, in which we use deep neural networks, a kind of deep learning technique, instead of the SVM. Deep learning does not require learning all input data at once because the network can be trained with small mini‐batches. Experimental results show that the CGBVS‐DNN outperformed the original CGBVS with a quarter million CPIs. Results of cross‐validation show that the accuracy of the CGBVS‐DNN reaches up to 98.2 % (σ<0.01) with 4 million CPIs.
Expression of glycosylated α‐dystroglycan in newborn skeletal and cardiac muscles of fukutin related protein (FKRP) mutant mice
Authors: Keramaris Elizabeth , Lu Pei J. , Tucker Jason , Lu Qi L. 
Published: August 2016

ABSTRACTIntroduction: Mutations in the Fukutin related protein (FKRP) gene are characterized by a lack of functionally glycosylated α‐dystroglycan (F‐α‐DG) in muscles. A small number of fibers retain the capacity to produce strong IIH6 reactive glycosylated‐α‐DG (g‐α‐DG) in muscles of both FKRP mutant animals and patients. Methods: We examined the expression of g‐α‐DG in limb, diaphragm, and cardiac muscles of newborn FKRP mutants and LARGEmyd mice with IIH6 antibody. Results: Near‐normal levels of g‐α‐DG were detected in all 3 muscles in the FKRP448LNeo‐ mutant. Expression was limited within the first 8 postnatal days with decreasing levels. No expression was identified in LARGEmyd mice. Conclusions: Temporary expression of glycosylated‐α‐DG in newborn FKRP mutant muscles is LARGE‐ and mutant FKRP‐dependent. The capability of mutant FKRP with a severe clinic phenotype to produce glycosylated‐α‐DG provides a new perspective for possible approaches to mitigate FKRP deficiency. Muscle Nerve 55: 582–590, 2017
Exploration of the conformational landscape in pregnane X receptor reveals a new binding pocket
Authors: Chandran Aneesh , Vishveshwara Saraswathi 
Published: August 2016

AbstractLigand‐regulated pregnane X receptor (PXR), a member of the nuclear receptor superfamily, plays a central role in xenobiotic metabolism. Despite its critical role in drug metabolism, PXR activation can lead to adverse drug‐drug interactions and early stage metabolism of drugs. Activated PXR can induce cancer drug resistance and enhance the onset of malignancy. Since promiscuity in ligand binding makes it difficult to develop competitive inhibitors targeting PXR ligand binding pocket (LBP), it is essential to identify allosteric sites for effective PXR antagonism. Here, molecular dynamics (MD) simulation studies unravelled the existence of two different conformational states, namely “expanded” and “contracted”, in apo PXR ligand binding domain (LBD). Ligand binding events shifted this conformational equilibrium and locked the LBD in a single “ligand‐adaptable” conformational state. Ensemble‐based computational solvent mapping identified a transiently open potential small molecule binding pocket between α5 and α8 helices, named “α8 pocket”, whose opening‐closing mechanism directly correlated with the conformational shift in LBD. A virtual hit identified through structure‐based virtual screening against α8 pocket locks the pocket in its open conformation. MD simulations further revealed that the presence of small molecule at allosteric site disrupts the LBD dynamics and locks the LBD in a “tightly‐contracted” conformation. The molecular details provided here could guide new structural studies to understand PXR activation and antagonism.
Application of gas chromatography/tandem mass spectrometry to determine a wide range of petrogenic alkylated polycyclic aromatic hydrocarbons in biotic samples
Authors: Sørensen Lisbet , Meier Sonnich , Mjøs Svein A. 
Published: August 2016

RationaleDue to the inherent toxicity of these compounds, analysis of petrogenic alkylated polycyclic aromatic hydrocarbons (PAHs) and heteroaromatic compounds in environmental samples is crucial. However, most existing methods are not sensitive enough when the analyte concentrations are low. Gas chromatography/tandem mass spectrometry (GC/MS/MS) is well suited to tackle this challenge, but methods are yet to be fully developed.MethodsA gas chromatograph coupled with a triple quadrupole mass spectrometer operated in multiple reaction monitoring (MRM) mode was applied for the analysis. MRM transitions and analytical conditions were optimized for the cluster analysis of 24 different compound classes of alkylated PAHs and heteroaromatics present in crude oils. Further, the method was verified and applied to analyze the body burden of these compounds in crude oil‐exposed haddock eggs.ResultsA comprehensive and sensitive method for the determination of C1‐C4 alkylated naphthalenes, benzothiophenes, fluorenes, phenanthrenes, dibenzothiophenes, chrysenes, pyrenes and fluoranthenes was developed. The method showed good precision (RSD <15%), and the obtained concentrations were similar to those obtained by traditional GC/MS analysis.ConclusionsWe demonstrate the successful application of this method towards crude oil‐exposed fish eggs, where we are able to precisely measure total PAH body burden below 0.5 μg/g. The demonstrated method facilitates further miniaturization in sample preparation. Copyright © 2016 John Wiley & Sons, Ltd.