bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of Thienylchalcones as hMAO‐B Inhibitors: Synthesis, Biochemistry and Molecular Dynamics Studies
Authors: Mathew Bijo , Uçar Gülberk , Rapheal Clariya , Mathew Githa E. , Joy Monu , Machaba Kgothatso E. , Soliman Mahmoud E. S. 
Published: December 2017

AbstractThe design of selective, reversible and non‐toxic hMAO−B inhibitors has received increasing attention due to their perceived utility in targeting of neurological disorders like Alzheimer's and Parkinson's diseases. For this purpose, herein, we report the inhibitory studies on monoamine oxidase of a series of (2E)‐1‐(2, 5‐dichlorothiophen‐3‐yl)‐3‐(4‐substitutedphenyl) prop‐2‐en‐1‐ones (S1‐S9). All the compounds were found to be competitive, selective, and reversible inhibitors of hMAO−B except (2E)‐1‐(2, 4‐dichlorothiophen‐3‐yl)‐3‐(4‐nitrophenyl) prop‐2‐en‐1‐one (S6) which is found to be non‐selective MAO inhibitor. The potent hMAO−B inhibitor, (2E)‐1‐(2, 4‐dichlorothiophen‐3‐yl)‐3‐[4‐(dimethylamino) phenyl] prop‐2‐en‐1‐one (S4), showed a Ki value of 0.041 μM better than the standard drug, selegiline (hMAO−B with Ki= 0.302 μM). Moreover, S4, was nontoxic in cultured hepatic cells at 5 and 25 μM, with 94.44 and 88.00% viable cells, respectively. Molecular docking and molecular dynamics simulation studies were carried out using Autodock‐vina and Amber 14 to understand the molecular level interaction and energy relation of MAO isoforms with selective MAO−B inhibitor, S4.
Nanomolar Detection of Al(III) Ion by Hydrazones Carrying Benzothiazole and Substituted Phenol Groups
Authors: Behera Nibedita , Manivannan Vadivelu 
Published: December 2017

AbstractTwo new hydrazones L1H (2‐(2‐(2,3‐dihydroxy)benzylidenehydrazinyl)benzothiazole) and L2H (2‐((2‐(2‐hydroxy)(4‐N,N‐diethylamino))benzylidenehydrazinyl)benzothiazole) were synthesized using 2‐hydrazinylbenzothiazole and 2,3‐dihydroxybenzaldehyde or 4‐(diethylamino)‐2‐hydroxybenzaldehyde. The probe L1H showed an absorption peak at 340 nm while L2H at 375 nm, in MeOH/HEPES buffer (pH=7.3; 8:2, v/v). Upon gradual addition of AlCl3 to L1H, intensity of the peak at 340 nm decreased and a new band appeared with a peak at 400 nm. Similarly upon adding AlCl3 to L2H, new peaks at 405 and 420 nm grew in intensity with concomitant decrease in absorbance peak at 375 nm, having quasi isosbestic point at 395 nm. Both these probes are weakly emissive in nature. Incremental addition of AlCl3 to the MeOH/HEPES buffer solution of L1H gave turn‐on response having emission maximum at 480 nm and L2H at 450 nm with a shoulder at 468 nm. Turn‐On responses of L1H and L2H towards Al3+ ion were result of inhibition of PET process which in turn allowed chelation induced enhanced fluorescence (CHEF) effect becoming operational. Job's plot obtained from the titration experiments yielded 1:1 stoichiometry for Al3+ ion, hence the formulae [Al(L1)Cl2(H2O)] and [Al(L2)Cl2(H2O)] were assigned. Addition of Na2EDTA to [Al(L1)Cl2(H2O)] and [Al(L2)Cl2(H2O)] reproduced UV‐visible spectrum that is characteristic of free L1H/L2H.
Reactions of 2,6‐Toluene Diisocyanate with Alcohols: Kinetic Studies in the Absence and Presence of Catalysts
Authors: Nagy Lajos , Nagy Tibor , Kuki Ákos , Oláh Réka , Lakatos Csilla , Zsuga Miklós , Kéki Sándor 
Published: December 2017

AbstractThe kinetics of the reaction between 2,6‐toluene diisocyanate (2,6‐TDI) and alcohols with varying carbon chain lengths and a primary or secondary hydroxyl group in the absence and presence of tin(II) 2‐ethylhexanoate (TEH) as a catalyst were studied. The alcohols were applied in high molar excess relative to 2,6‐TDI to obtain a pseudo‐first‐order dependence on 2,6‐TDI. Based on the kinetic results, it was found that (i) 2,6‐TDI reacts faster with alcohols with longer carbon chains than those with shorter ones, (ii) secondary alcohols are approximately 3 times less reactive towards 2,6‐TDI than primary ones, and (iii) after the first isocyanate group has been reacted, the reactivity of the remaining isocyanate group decreases. Furthermore, the rate constants were found to depend linearly on catalyst concentration.
Local Structure Investigation of Mn‐ and Co–Doped TiO2 Thin Films by X‐Ray Absorption Spectroscopy
Authors: Yadav Ashok Kumar , Haque Sk. Maidul , De Rajnarayan , Ahmed Md. Azaharuddin , Srihari Velaga , Gupta Mukul , Phase Deodatta M. , Bandyopadhyay Sudipta , Jha Shambu Nath , Bhattacharyya Dibyendu 
Published: December 2017

AbstractMn and Co doped TiO2 thin films with varying doping concentrations have been prepared by r.f magnetron sputtering technique. Preliminary structural characterization of the samples have been carried out by Grazing Incidence X‐ray diffraction (GIXRD) measurements. Detail studies by X‐ray Absorption Spectroscopy (XAS), which comprises of both X‐ray Near Edge Structure (XANES) and Extended X‐ray Absorption Fine Structure (EXAFS) techniques, have been carried out on the samples at dopants (Mn,Co) and host (Ti) K‐edges to have an overall information on the local structures around the above atomic sites of the samples. The information obtained above have been corroborated by O K‐edge XANES, metal L‐edge XAS measurements and theoretical simulations of XANES spectra also. Finally room temperature ferromagnetism observed in the doped TiO2 samples has been explained on the basis of the above structural information.
Intramolecular Si⋅⋅⋅O Tetrel Bonding: Tuning of Substituents and Cooperativity
Authors: Wei Yuanxin , Li Qingzhong , Yang Xin , McDowell Sean A. C. 
Published: December 2017

AbstractA computational study of an intramolecular tetrel bond in o‐methoxymethyl‐PhSiF3 (P) and its derivatives at the 4 and 5 positions by substituents X (4‐X−P and 5‐X−P, X=F, Cl, Br, NO2, OH, and NH2) has been performed. The Si⋅⋅⋅O interaction is characterized by the short Si⋅⋅⋅O distance, strong orbital interaction, large interaction energy, and negative energy density. Substituents do not greatly affect the strength of the intramolecular Si⋅⋅⋅O interaction but some interesting results are obtained. The electron‐donating group in 5‐OH−P strengthens this interaction more than the electron‐withdrawing group in 5‐NO2‐P. The interaction energy of the intramolecular Si⋅⋅⋅O interaction has been computed with three different methods and the most reliable result is obtained with an expression using the potential energy density at the Si⋅⋅⋅O bond critical point. When a water molecule is attached to P to form an OH⋅⋅⋅F hydrogen bond, the intramolecular Si⋅⋅⋅O interaction is greatly enhanced yielding an interaction energy up to ∼12 kcal mol−1.
Ratiometric Fluorescent Chemosensor for Zn2+ Ions in Environmental Samples Using Supermicroporous Organic‐Inorganic Structures as Potential Platforms
Authors: El‐Sewify Islam M. , Shenashen Mohamed A. , Shahat Ahmed , Yamaguchi Hitoshi , Selim Mahmoud M. , Khalil Mostafa M.H. , El‐Safty Sherif A. 
Published: December 2017

AbstractWe report the fabrication of supermicroporous, fluorometric chemosensors with a Zr‐metal–organic framework as carrier. The fabricated ratiometric fluorescent chemosensors (RFCs) were suitable for the selective and sensitive fluorometric recognition of ultra‐trace concentrations of heavy metals, such as Zn2+ ions, in water sources. The RFCs were designed by performing direct pressure‐assisted immobilization of a hydrophobic organic probe inside supermicroporous cubic Zr‐MOFs. The immobilized organic probe exhibited high sensitivity and selectivity toward Zn2+ in a uniform super‐microchannel pore, long‐range intergrowing crystal structures. Ratiometric fluorometric sensing assay of the Zn2+ ions revealed the high selectivity of the ions in a mixture of multiple interfering ions. This phenomenon was due to the structure of the RFCs, the pH of the system, the composition of the competitive ion system, and the Zn‐to‐RFCs binding process, which occurred via electron transfer. The RFCs exhibited a wide detection and monitoring range for Zn2+ ions. The lower limit of detection was 0.16 ppb, and a fast response within seconds was observed during complexation with the Zn2+ ion target. The surface functionality and long‐term stability of RFCs enable the practical and multiple reuse/cycles of Zn2+ ion recognition.
Facile Designing of a Colorimetric Plasmonic Gold Nanosensor for Selective Detection of Cysteine over Other Biothiols
Authors: Sanskriti Isha , Upadhyay Kaushal K. 
Published: December 2017

AbstractHerein, we present a facile synthesis of well dispersed gold nanoparticles (AuNPs) using 1,3‐diamino‐2‐hydroxypropane‐N,N,N’,N’‐tetraacetic acid (TA) as reducing as well as stabilizing agent. The bright red colored gold nanoparticles were found to be quite stable within the broad pH range of 4 to 10. The same detected Cysteine (Cys) selectively over other common interfering biothiols like homocysteine (Hcy), glutathione (GSH) and methionine (Met). The bright red colored AuNPs displayed bluish gray color upon their interaction with Cys within ˜20 seconds only. The ability towards assay of Cys in pharmaceutical sample made this probe further lucrative. The possibility of onspot assessement by this probe was also tested through cotton swab experiment.
Facile Fabrication of Sulfur/Graphene Composite for High‐Rate Lithium‐Sulfur Batteries
Authors: Chabu Johnny Muya , Zeng Ke , Walle Maru Dessie , You Xiaolong , Zhang Mengyuan , Li Yajuan , Liu You‐Nian 
Published: December 2017

AbstractA sulfur‐graphene composite (SG) is obtained by hydrothermally treating elemental sulfur powder with graphene oxide under alkaline condition. Structural and morphological analysis indicates a highly dispersed non‐crystalline state of sulfur throughout the material. Raman theoretical calculation reveals sulfur molecules in SG are identical to calculated S8 allotrope. The resulting SG cathode provides high sulfur utilization of 97.67% as it delivers an extremely high initial capacity of 1636.1 mAh g−1 at 0.2 C. Even at high rates such as 1 C and 3 C, SG still delivers excellent performance. Moreover their capacity retention is high around 64.84% and 67.86% after 50 cycles at 1 C and 3 C, respectively. It exhibits outstanding stable cycling capability, with an initial capacity at 866.9 mAh g−1 at 5 C with a remaining capacity of 385.4 mAh g−1 after 250 cycles. Such exceptional performance lay in the highly dispersed nature of amorphous sulfur, the unique three dimensional architecture of graphene coupled to its strong intimate contact with sulfur. The presented design is extremely simple, scalable and promising for future commercialization of Li−S cells.
Use of Nanomagnetic Sulfated Zirconia (Fe3O4@ZrO2/SO42−) as Sustainable Heterogeneous Acid Catalyst for Synthesis of Spiroheterocycles under Solvent‐Free Conditions
Authors: Tailor Yogesh Kumar , Khandelwal Sarita , Gopal Ram , Rushell Esha , Prajapati Anamika , Kumar Mahendra 
Published: December 2017

AbstractAn efficient and environmentally benign domino protocol has been presented for the synthesis of structurally diverse spiroheterocycles spiroannulated with 1,3,4‐thiadiazolo[3, 2‐a]pyrimidine involving three‐ component reaction of 2‐amino‐1,3,4‐thiadiazole, isatin/N‐methyl‐4‐piperidone/1,2‐acenaphthylenedione and carbonyl compounds catalyzed by magnetically recoverable and reusable nanocrytalline sulfated zirconia (Fe3O4@ZrO2/SO42−) under solvent free conditions with grinding at room temperature. The use of magnetically recyclable and reusable catalyst, mild reaction conditions with operational simplicity (grinding), and excellent product yields are significant features of the present synthetic protocol. Moreover, easy magnetic separation of the catalyst eliminates the requirement of catalyst filtration after completion of the reaction and the catalyst remains highly active even after recycled several times.
A Facile Green Reduction for Graphene‐Silver Nanocomposite Using Betel Leaf Extract for the Photocatalytic Degradation of Water Pollutants
Authors: Chandu Basavaiah , Nurbasha Sharmila , Bollikolla Hari Babu 
Published: December 2017

AbstractGreen leaves are utilized in the green synthesis of various nanomaterials as these are rich sources of various biomolecules useful to control the growth of nanoparticles and as reducing agents. In this report, the in situ synthesis of a nanocomposite of silver decorated on reduced graphene oxide sheets using betel leaf extract as stabilizing and reducing agent is presented. The formation of nanocomposite is confirmed by Ultraviolet‐Visible, Fourier Transform Infrared and Raman spectroscopic techniques. The X‐Ray Diffraction results revealed the Face Centered Cubic structure of silver nanoparticles (Ag NPs) with a particle size of 28 nm. The sheet structure of reduced graphene oxide and uniformly distributed Ag NPs on these sheets is confirmed by High Resolution Scanning Electron Microscope analysis. The obtained nanocomposite exhibited good photocatalytic efficiency (95% in 2 h) against a model pollutant, methylene blue in sun light.
Diels‐Alder Reaction of Levoglucosenone with a Protected cis‐Cyclohexadienediol: Structural and Electronic Basis behind the Unexpected Stereoselectivity
Authors: Martínez Sebastián , Carrau Gonzalo , Gonzalez David , Veiga Nicolás 
Published: December 2017

AbstractRecently, we found that the Diels–Alder reaction between levoglucosenone and the acetonide of (1S,2R)‐3‐methylcyclohexa‐3,5‐diene‐1,2‐diol occurs through the most hindered face of the diene. This unexpected facial selectivity has no precedent for di‐O‐isopropylidene‐protected dienes, and the reasons behind it remain unclear. Here, we expand on our earlier findings, computationally assessing the structural and electronic factors responsible for this unforeseen stereoselectivity. The B3LYP/6‐31+G(d,p) results identify the three main adducts (β‐endo‐ortho:α‐endo‐meta:α‐exo‐ortho), giving a product ratio (63:9:28) that is in line with the experimental value (64:16:10). The β‐endo attack allows to maximize the electrostatic attraction between the reactants, giving rise to dipolar C−O⋅⋅⋅H−C interactions with the isopropylidene group at the transition state. The endo/exo preference can be rationalized through electrostatic repulsion and steric hindrance between the isopropylidene and methylene fragments. Finally, the non‐classical C=O⋅⋅⋅H−C hydrogen bonding stabilizes the ortho transition structures, making them more polar and asynchronous.
The Role of Glutathione and Ethanol in Dictating the Emission Dynamics of Natural Resources‐Derived Highly Luminescent Carbon Nanodots
Authors: Nema Akansh , Pareek Rakshit , Rai Tripti , Panda Debashis 
Published: December 2017

AbstractAn integrative approach is adopted to address the intriguing aspect of fluorescence dynamics in carbon nanodots (CNDs). In this contribution, we offer two different types of highly luminescent CNDs derived from a natural‐resource and glucose‐amine‐CTAB reactions by employing fast and cost‐effective methods. Lemon‐juice derived CNDs (CND1) exhibit excitation‐independent emission, whereas the other one shows excitation‐dependent fluorescence; the former one possesses more of a nanosheet like structure whereas later exhibit particle behavior. We also provide conclusive evidence on the existence of the CNDs in a state of aggregation in aqueous solution and the presence of high molecular weight structure, contrary to reported observations. Circular dichroism studies suggest strong H‐bonding networks in CNDs. The juxtaposition of experimental findings indicates the presence of pyrrolopyridine‐type fluorophoric moiety. The temperature‐dependent luminescence properties of CNDs is highly reversible in nature therefore, synthesized CNDs can find potential application as nanothermometer. Metal‐ion dependent modulation of fluorescence properties of CND1 suggest its applications in ion‐sensing.
Multi‐Stimuli Response Displaying Novel Phenothiazine‐Based Non‐Planar D‐π‐A Hydrazones: Synthesis, Characterization, Photophysical and Thermal studies
Authors: Sachdeva Tanisha , Bishnoi Swati , Milton Marilyn Daisy 
Published: December 2017

AbstractMulti‐stimuli responsive non‐planar D‐π‐A hydrazones bearing non‐planar phenothiazine as donor (D) and benzothiazole and dinitrophenyl rings as acceptor (A) were synthesized and their structural, photophysical, thermochromic, mechanofluorochromic (MFC) and acidochromic properties were studied. Thermal gravimetric analysis (TGA) and spectrophotometric studies revealed higher thermal stability, better ICT character and enhanced D‐A intramolecular interactions in phenothiazine hydrazone bearing phenyl pendant ring. Hydrazones bearing benzothiazole ring as A displayed aggregation induced emission enhancement (AIEE) as well as acidochromism in presence of volatile acids like TFA. Greater extent of change in color and emission wavelength under external pressure revealed better MFC behavior of phenothiazine hydrazone bearing phenyl pendant ring. Two of the hydrazones exhibited reversible mechanofluorochromism on fuming their ground samples with DCM vapors. Structure‐property relationship studied by single crystal X‐ray diffraction patterns suggested the existence of twisted molecular conformation and weak intermolecular interactions such as π–π, C‐H–π and S–S which played a vital role in the phase transition from crystalline to amorphous state under mechanical stress which was further justified by powder X‐ray diffraction patterns.
Ammonia Synthesis from Nitrogen and Water by Electricity Using an Electrochemical Cell with Ru Catalyst, Hydrogen‐Permeable Pd‐Ag Membrane, and Phosphate‐Based Electrolyte
Authors: Imamura Kanako , Matsuyama Masako , Kubota Jun 
Published: December 2017

AbstractConversion from renewable energy‐based electricity to chemical fuels is a promising technology in the near future. NH3 is one of the candidates as chemical energy carriers, which can be synthesized from N2 and H2O using electricity. A new NH3 synthesis from N2 and H2O by electricity at 250 °C using an electrochemical cell that consists of a Ru/Cs+/MgO catalyst, Pd−Ag membrane cathode, a CsH2PO4/SiP2O7 electrolyte, and Pt anode has been proposed in this work. An NH3 synthesis rate of 7.7×10−10 mol s−1 cm−2 was obtained at 6.4 mA cm−2 and 1.2 V under a flow of N2 at 1 cm3 min −1. The current efficiency for NH3 synthesis was 3.5%, and the other part was used for H2 formation. The examination depending on the flow rate of N2 was demonstrated and the small flow of N2 was found to be preferred for NH3 synthesis. The present cell is expected to open up new perspectives in the developments of the most suitable materials as NH3 catalysts, hydrogen membranes, and water electrolyzer for combination in a reactor at the intermediate temperature.
On the Convergence of Asynchronous Parallel Iteration with Unbounded Delays
Authors: Peng Zhimin , Xu Yangyang , Yan Ming , Yin Wotao 
Published: December 2017

AbstractRecent years have witnessed the surge of asynchronous parallel (async-parallel) iterative algorithms due to problems involving very large-scale data and a large number of decision variables. Because of asynchrony, the iterates are computed with outdated information, and the age of the outdated information, which we calldelay, is the number of times it has been updated since its creation. Almost all recent works prove convergence under the assumption of a finite maximum delay and set their stepsize parameters accordingly. However, the maximum delay is practically unknown. This paper presents convergence analysis of an async-parallel method from a probabilistic viewpoint, and it allows for large unbounded delays. An explicit formula of stepsize that guarantees convergence is given depending on delays’ statistics. With$$p+1$$p+1identical processors, we empirically measured that delays closely follow the Poisson distribution with parameterp, matching our theoretical model, and thus, the stepsize can be set accordingly. Simulations on both convex and nonconvex optimization problems demonstrate the validness of our analysis and also show that the existing maximum-delay-induced stepsize is too conservative, often slows down the convergence of the algorithm.
Intact striatal dopaminergic modulation of reward learning and daily-life reward-oriented behavior in first-degree relatives of individuals with psychotic disorder
Authors: Kasanova Zuzana , Ceccarini Jenny , Frank Michael J. , van Amelsvoort Thérèse , Booij Jan , van Duin Esther , Steinhart Henrietta , Vaessen Thomas , Heinzel Alexander , Mottaghy Felix , Myin-Germeys Inez 
Published: December 2017

BackgroundAbnormalities in reward learning in psychotic disorders have been proposed to be linked to dysregulated subcortical dopaminergic (DA) neurotransmission, which in turn is a suspected mechanism for predisposition to psychosis. We therefore explored the striatal dopaminergic modulation of reward processing and its behavioral correlates in individuals at familial risk for psychosis.MethodsWe performed a DA D2/3receptor [18F]fallypride positron emission tomography scan during a probabilistic reinforcement learning task in 16 healthy first-degree relatives of patients with psychosis and 16 healthy volunteers, followed by a 6-day ecological momentary assessment study capturing reward-oriented behavior in the everyday life.ResultsWe detected significant reward-induced DA release in bilateral caudate, putamen and ventral striatum of both groups, with no group differences in its magnitude nor spatial extent. In both groups alike, greater extent of reward-induced DA release in all regions of interest was associated with better performance in the task, as well as in greater tendency to be engaged in reward-oriented behavior in the daily life.ConclusionsThese findings suggest intact striatal dopaminergic modulation of reinforcement learning and reward-oriented behavior in individuals with familial predisposition to psychosis. Furthermore, this study points towards a key link between striatal reward-related DA release and pursuit of ecologically relevant rewards.
Application of optimal band-limited control protocols to quantum noise sensing
Authors: Frey V. M. , Mavadia S. , Norris L. M. , de Ferranti W. , Lucarelli D. , Viola L. , Biercuk M. J. 
Published: December 2017

AbstractEssential to the functionality of qubit-based sensors are control protocols, which shape their response in frequency space. However, in common control routines out-of-band spectral leakage complicates interpretation of the sensor’s signal. In this work, we leverage discrete prolate spheroidal sequences (a.k.a. Slepian sequences) to synthesize provably optimal narrowband controls ideally suited to spectral estimation of a qubit’s noisy environment. Experiments with trapped ions demonstrate how spectral leakage may be reduced by orders of magnitude over conventional controls when a near resonant driving field is modulated by Slepians, and how the desired narrowband sensitivity may be tuned using concepts from RF engineering. We demonstrate that classical multitaper techniques for spectral analysis can be ported to the quantum domain and combined with Bayesian estimation tools to experimentally reconstruct complex noise spectra. We then deploy these techniques to identify previously immeasurable frequency-resolved amplitude noise in our qubit’s microwave synthesis chain.