bluuebunny/crossref_metadata_2025 huggingface dataset:
Free‐breathing whole‐heart 3D cine magnetic resonance imaging with prospective respiratory motion compensation
Authors: Moghari Mehdi H. , Barthur Ashita , Amaral Maria E. , Geva Tal , Powell Andrew J.
Published: December 2017

Purpose

To develop and validate a new prospective respiratory motion compensation algorithm for free‐breathing whole‐heart 3D cine steady‐state free precession (SSFP) imaging.

Methods

In a 3D cine SSFP sequence, 4 excitations per cardiac cycle are re‐purposed to prospectively track heart position. Specifically, their 1D image is reconstructed and routed into the scanner's standard diaphragmatic navigator processing system. If all 4 signals are in end‐expiration, cine image data from the entire cardiac cycle is accepted for image reconstruction. Prospective validation was carried out in patients (N = 17) by comparing in each a conventional breath‐hold 2D cine ventricular short‐axis stack and a free‐breathing whole‐heart 3D cine data set.

Results

All 3D cine SSFP acquisitions were successful and the mean scan time was 5.9 ± 2.7 min. Left and right ventricular end‐diastolic, end‐systolic, and stroke volumes by 3D cine SSFP were all larger than those from 2D cine SSFP. This bias was < 6% except for right ventricular end‐systolic volume that was 12%. The 3D cine images had a lower ventricular blood‐to‐myocardium contrast ratio, contrast‐to‐noise ratio, mass, and subjective quality score.

Conclusion

The novel prospective respiratory motion compensation method for 3D cine SSFP imaging was robust and efficient and yielded slightly larger ventricular volumes and lower mass compared to breath‐hold 2D cine imaging. Magn Reson Med 80:181–189, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Evolution of pore structure and hydraulic conductivity of randomly distributed soluble particle mixture
Authors: Shin Hosung , Hung Truong Q. , Lee Jong‐Sub , Choo Hyunwook , Lee Changho
Published: December 2017

The plane strain behavior of particulate mixtures containing soluble particles was investigated by conducting both laboratory tests and numerical analysis. To perform the laboratory experiments, soluble mixtures were prepared using photoelastic disks and ice disks with diameters in the ratios (Dice disk/Dphotoelastic disk) of 0.5 and 0.7, and the evolution of the force chain and pore structure was monitored during the dissolution of the ice disks. Subsequently, numerical analysis was conducted by using the 2‐dimensional discrete element method for the soluble mixtures, and it was compared with the experimental results. Additionally, parametric studies were implemented by varying the particle size ratios between the soluble and non‐soluble particles and the volumetric fraction of the soluble particles. The results of the laboratory experiments and numerical analysis demonstrate that (1) after the dissolution of the soluble particles, the pore fabric of the specimens changed, resulting in a force chain changes, local void increases, and coordination number decreases; (2) the effects of soluble particles on the macro‐behaviors of the mixtures could be divided into 3 zones based on the particle size ratios between the soluble and non‐soluble particles and volumetric fraction of soluble particles. These zones were as follows: (Zone 1)—with a small total soluble volume, slight decrease in the in situ lateral pressure (K0), and minor increase in the hydraulic conductivity (k); (Zone 2)—with a moderate soluble particle; the dissolution generated a honey‐comb particle structure; (Zone 3)—the total soluble volume was very large, and the high volumetric fraction of the dissolving particle collapsed the pore structure, decreasing in the in situ lateral pressure (K0) but increasing the hydraulic conductivity (k). The horizontal stress returned to almost the original level, and the internal arching formation increased significantly with the hydraulic conductivity (k).
Determinants of the recovery of financially distressed nonprofits
Authors: Searing Elizabeth A.M.
Published: December 2017

Financial ratios are traditionally used to predict and diagnose financial vulnerability; this is helpful, but leaves unanswered how the vulnerable nonprofit should prioritize this information in order to survive. Using panel data, this empirical study observes the financial behaviors of distressed nonprofits for 4‐year periods where the first 2 years are financially vulnerable. Two definitions of vulnerability are tested: when liabilities exceed assets (insolvency) and when net assets shrink by more than 25% annually (financial disruption). In determining which nonprofits recover during the final 2 years, we find that the type of vulnerability impacts which financial indicators a nonprofit should target, and that common tactics such as improving profitability may be counterproductive. Finally, we do not find evidence for liabilities of newness or smallness in the statistical analysis.
Improving and measuring transparency in NGOs: A disclosure index for activities and projects
Authors: Cabedo J. David , Fuertes‐Fuertes Iluminada , Maset‐LLaudes Amparo , Tirado‐Beltrán José Miguel
Published: December 2017

Nongovernmental organizations (NGOs) are established not with the aim of making profits but rather to provide social values by implementing different projects and activities. Transmitting complete information about these projects to society is a key element of transparency, as they operate within an atmosphere of public trust. Although there is a large body of literature on transparency in NGOs from a global perspective, very little research has been conducted on transparency within the area of projects and activities. This study takes a deeper look at this line and contributes to the literature on transparency in NGOs by proposing an index to measure the information transparency of the projects implemented by these organizations. The index captures three dimensions of the information about the projects (technical, financial, and scope) and makes it possible to: analyze the level of transparency of the portfolio of projects, detect the specific aspects that could be improved in each organization, and carry out comparisons among organizations.
Contested discourses and culture sensitivity: Norwegian nursing students' experience of clinical placement in Nicaragua
Authors: Grudt Solveig Kirsti , Hadders Hans
Published: December 2017

Aim

The purpose of this study was to gain understanding of Norwegian students' practical experience of “culture sensitivity.”

Design

Using focus‐group interviews and individual written assignments, we draw on a Foucauldian‐inspired approach to analyse nursing students' narratives about their clinical placement in Nicaragua.

Method

Seven third‐year bachelor nursing students enrolled in a clinical placement programme on the Caribbean coast in Nicaragua and participated in focus‐group interviews. Interviews were conducted prior to their departure to Nicaragua and after their return to Norway. Other sources of data included learning objectives for clinical placement, written individual assignments with students' reflections about their experiences and achievement of learning objectives.

Results

Students expressed gradually increased awareness about the nursing discourses and power relations shaping clinical encounters throughout their learning trajectory in clinical placement. They became more aware of the politics of nursing practices through their experiences of clashes between different nursing discourses.
Effects of force fields on the conformational and dynamic properties of amyloid β(1‐40) dimer explored by replica exchange molecular dynamics simulations
Authors: Watts Charles R. , Gregory Andrew , Frisbie Cole , Lovas Sándor
Published: December 2017

The conformational space and structural ensembles of amyloid beta (Aβ) peptides and their oligomers in solution are inherently disordered and proven to be challenging to study. Optimum force field selection for molecular dynamics (MD) simulations and the biophysical relevance of results are still unknown. We compared the conformational space of the Aβ(1‐40) dimers by 300 ns replica exchange MD simulations at physiological temperature (310 K) using: the AMBER‐ff99sb‐ILDN, AMBER‐ff99sb*‐ILDN, AMBER‐ff99sb‐NMR, and CHARMM22* force fields. Statistical comparisons of simulation results to experimental data and previously published simulations utilizing the CHARMM22* and CHARMM36 force fields were performed. All force fields yield sampled ensembles of conformations with collision cross sectional areas for the dimer that are statistically significantly larger than experimental results. All force fields, with the exception of AMBER‐ff99sb‐ILDN (8.8 ± 6.4%) and CHARMM36 (2.7 ± 4.2%), tend to overestimate the α‐helical content compared to experimental CD (5.3 ± 5.2%). Using the AMBER‐ff99sb‐NMR force field resulted in the greatest degree of variance (41.3 ± 12.9%). Except for the AMBER‐ff99sb‐NMR force field, the others tended to under estimate the expected amount of β‐sheet and over estimate the amount of turn/bend/random coil conformations. All force fields, with the exception AMBER‐ff99sb‐NMR, reproduce a theoretically expected β‐sheet‐turn‐β‐sheet conformational motif, however, only the CHARMM22* and CHARMM36 force fields yield results compatible with collapse of the central and C‐terminal hydrophobic cores from residues 17‐21 and 30‐36. Although analyses of essential subspace sampling showed only minor variations between force fields, secondary structures of lowest energy conformers are different.
Identification of an antibody‐based immunoassay for measuring direct target binding of RIPK1 inhibitors in cells and tissues
Authors: Finger Joshua N. , Brusq Jean‐Marie , Campobasso Nino , Cook Michael N. , Deutsch Jennifer , Haag Heather , Harris Philip A. , Jenkins Earl L. , Joglekar Devika , Lich John D. , Maguire Sean , Nagilla Rakesh , Rivera Elizabeth J. , Sun Helen , Votta Bartholomew J. , Bertin John , Gough Peter J.
Published: December 2017

Therapies that suppress RIPK1 kinase activity are emerging as promising therapeutic agents for the treatment of multiple inflammatory disorders. The ability to directly measure drug binding of a RIPK1 inhibitor to its target is critical for providing insight into pharmacokinetics, pharmacodynamics, safety and clinical efficacy, especially for a first‐in‐class small‐molecule inhibitor where the mechanism has yet to be explored. Here, we report a novel method for measuring drug binding to RIPK1 protein in cells and tissues. This TEAR1 (Target Engagement Assessment for RIPK1) assay is a pair of immunoassays developed on the principle of competition, whereby a first molecule (ie, drug) prevents the binding of a second molecule (ie, antibody) to the target protein. Using the TEAR1 assay, we have validated the direct binding of specific RIPK1 inhibitors in cells, blood and tissues following treatment with benzoxazepinone (BOAz) RIPK1 inhibitors. The TEAR1 assay is a valuable tool for facilitating the clinical development of the lead RIPK1 clinical candidate compound, GSK2982772, as a first‐in‐class RIPK1 inhibitor for the treatment of inflammatory disease.
The challenge of herbicide resistance around the world: a current summary
Authors: Peterson Mark A , Collavo Alberto , Ovejero Ramiro , Shivrain Vinod , Walsh Michael J
Published: December 2017

Herbicide‐resistant weeds have been observed since the early years of synthetic herbicide development in the 1950s and 1960s. Since that time there has been a consistent increase in the number of cases of herbicide resistance and the impact of herbicide‐resistant weeds. Although the nature of crop production varies widely around the world, herbicides have become a primary tool for weed control in most areas. Dependence on herbicides continues to increase as global populations migrate away from rural areas to cities and the agricultural labor force declines. This increased use of herbicides and the concurrent selection pressure have resulted in a rise in cases of multiple resistance, leaving some farmers with few or no herbicide options for certain weed infestations. Global population and economic forces drive many farmer choices regarding crop production and weed control. The challenge is how to insert best management practices into the decision‐making process while addressing various economic and regulatory needs. This review endeavors to provide a current overview of herbicide resistance challenges in the major crop production areas of the world and discusses some research initiatives designed to address portions of the problem. © 2017 Society of Chemical Industry
Optimizing RNA‐seq studies to investigate herbicide resistance
Authors: Giacomini Darci A , Gaines Todd , Beffa Roland , Tranel Patrick J
Published: December 2017

Transcriptomic profiling, specifically via RNA sequencing (RNA‐seq), is becoming one of the more commonly used methods for investigating non‐target site resistance (NTSR) to herbicides due to its high throughput capabilities and utility in organisms with little to no previous sequence information. A review of the weed science RNA‐seq literature revealed some basic principles behind generating quality data from these types of studies. First, studies that included more replicates per biotype and took steps to control for genetic background had significantly better control of false positives and, consequently, shorter lists of potential resistance genes to sift through. Pooling of biological replicates prior to sequencing was successful in some cases, but likely contributed to an overall increase in the false discovery rate. Although the inclusion of herbicide‐treated samples was common across most of the studies, it ultimately introduced difficulties in interpretation of the final results due to challenges in capturing the right sampling window after treatment and to the induction of stress responses in the injured herbicide‐sensitive plants. RNA‐seq is an effective tool for NTSR gene discovery, but careful consideration should be given to finding the most powerful and cost‐effective balance between replicate number, sequencing depth and treatment number. © 2017 Society of Chemical Industry
Dynamic Light Scattering and FTIR Spectroscopic Investigations on the Reverse Micelles Produced During the Extraction of Nd(III) and Nitric Acid in Tetra Ethylhexyl Diglycolamide
Authors: Swami Kantamani Rama , Suneesh Asokan Sudha , Kumaresan Radhakrishnan , Venkatesan Konda Athmaram , Antony Malpan Pailo
Published: December 2017

The aggregation behaviour of reverse micelles, formed during the extraction of neodymium nitrate and nitric acid, in an organic phase composed of tetra‐bis(2‐ethylhexyl) diglycolamide (TEHDGA) in n‐dodecane (n‐DD) was studied, at various temperatures. The organic phase, 0.2 M TEHDGA/n‐DD was equilibrated with aqueous solutions of nitric acid in the presence and absence of neodymium nitrate. At certain nitric acid and Nd(III) concentration in aqueous phase, the organic phase underwent splitting into two phases, with top phase known as “diluent rich phase”, the other one known as “third phase” or “metal ion rich phase”. Dynamic light scattering, attenuated total reflectance (ATR) ‐Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopic methods were employed for probing the size and distribution of aggregates present in the organic phase before and after splitting. The investigations revealed that the aggregates, formed in organic phase, interact efficiently with the extracted metal ions and these interactions increased with increase in the concentration of nitric acid and neodymium nitrate in organic phase. In addition, the interaction among the reverse micelles in third phase appear to be very strong as compared to that observed in the organic phase before third phase formation, and such strong interactions resulted in a merger and narrow distribution of reverse micelles in third phase.
A Novel Copper Complex of Proline‐Based Mono(phenol) Amine Ligand (Hlpro) Immobilized in SBA‐15 as a Model Catalyst of Galactose Oxidase
Authors: Saberikia Iraj , Safaei Elham , Karimi Babak , Lee Yong‐Ill
Published: December 2017

A novel copper complex of proline‐based mono(phenol) amine (HLPro) immobilized in SBA‐15 as a model of Galactose oxidase enzyme has been synthesized and characterized using transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), Fourier‐transform infrared (FT‐IR), N2 adsorption–desorption, thermogravimetric analysis (TGA), and elemental analysis. The immobilized complex was found to heterogeneously catalyse the aerobic oxidation of alcohols under mild conditions to the corresponding aldehydes in the presence of TEMPO and in the absence of any additive such as base. The catalyst was easily recovered by a simple filtration and was subsequently reused in the four reaction cycles without considerable loss of activity.
Investigations of Microstructure and Dc Conductivity of V2O5‐Nd2O3 Glass Nanocomposites
Authors: Das Anindya Sundar , Roy Madhab , Roy Debasish , Kar Tanusree , Rath Satchidananda , Bhattacharya Sanjib
Published: December 2017

The present work points to highlight the structural, optical and electrical properties of some semiconducting V2O5‐Nd2O3 glass nanocomposites. Structural properties such as identification of nano phases in the glassy matrix and crystallite sizes have been evaluated using X‐ray diffraction (XRD) and transmission electron microscopy (TEM). Fourier transform infrared spectroscopy (FT‐IR) and Raman spectroscopy have been used to find out nature of bonding in the as‐synthesized glass nanocomposites. Optical properties have been analyzed using Ultraviolet‐visible (UV‐Vis) absorption spectroscopy and we have studied Dc electrical conductivity at various temperatures. The crystallite sizes of V2O5 and NdVO4 embedded in the present glassy systems are found to increase with V2O5 content. Stretching vibration of νs (VO4), Nd–O bond, V–O bond, orthorhombic phase of V2O5 are present in the present system. The small‐polaron hopping theory could adequately explain the temperature dependence of the electrical Dc conductivity. It is observed that the fundamental absorption edge and cutoff wavelength shift towards red with the increase of V2O5 content. The fundamental UV‐Vis absorption spectra have been analyzed, which indicates indirect band transitions. It is also observed that optical band gap energy decreases with increase in concentration of V2O5 due to structural changes.
Lead Iodide Microcrystals in Carbon Composite Matrix for Low Power Photodetectors
Authors: Madhusudanan Sreejith P. , Krishna Orsu Vamsi , Mohanta Kallol , Batabyal Sudip K.
Published: December 2017

Lead iodide (PbI2) microcrystals based photodetector were developed by a simple printing method. Carbon composite paste was fabricated by homogeneous mixing of PbI2 microcrystals, commercial graphite powder, and activated carbon. Composite carbon paste was printed on top of thermally deposited Al electrodes on the glass substrates to fabricate the photodetector. Controlled variation of PbI2 loading established that 10% PbI2 in carbon composite is the best candidate for the highest On/Off ratio. The photo generated current was manifested by the defect present in the graphite and the PbI2 microcrystals interfaces. The effect enables us to develop cost effective printing based photodetector which can work in very low voltage region for low‐power printed electronics.
Effect of Different Chemical Species on the Behavior of Tyrosine in a Typical BR Oscillatory Chemical Reaction
Authors: Dar Farhad Nisar A. , Peerzada Ghulam M. , Ganaie Nadeem B. , Rashid Sna
Published: December 2017

Effect on the behavior of Tyrosine through a malonic acid (MA) based Briggs‐Rauscher (BR) oscillatory system was studied in order to understand the mechanistic details of thyroid metabolism in vitro, specifically the iodination of tyrosine. It was observed that the present BR system employing tyrosine as a main additive and malonic acid as substrate provides an example of entrainment oscillations, in which malonic acid is responsible for oscillations and in presence of tyrosine, the system showed different oscillatory behavior. The effects of various other chemical species such as SeO2, KSCN, KNO3, KBr and Fe(III) on the tyrosine in this malonic acid based BR system are studied. The study was supported by UV‐Visible spectrophotometry to study the interactions of these chemical species with Dushmann reaction, which is one of the important reaction steps in BR reaction mechanism, in order to investigate the key factors responsible for tyrosine iodination responsible for thyroxin formation. Needless to mention that, all the aforesaid chemical species have due role in normal thyroid metabolism in vivo and as such, the present BR system containing tyrosine as main (first) additive can help in understanding of thyroid metabolism.
One‐Pot Synthesis of Tetrahydropyridine Derivatives: Liquid Salt Catalyst vs Glycolic Acid Promoter. Structure and Antiradical Activity of the New Products
Authors: Petrović Zorica D. , Simijonović Dušica , Đorović Jelena , Milovanović Vesna , Marković Zoran , Petrović Vladimir P.
Published: December 2017

Diethanolammonium hydrogensulfate (DHS), as a liquid salt, and glycolic acid (GA) were used for the synthesis of highly functionalized tetrahydropyridines (THPs). Due to the simplicity of the reaction procedure, excellent diastereoselectivity, and catalyst regeneration, these green protocols may be considered as an attractive approach for the preparation of THPs. Unlike numerous reported reactions for the synthesis of THPs that last for hours and with heating, GA‐promoted reactions finished mostly within an hour and at room temperature. As improvement to other organocatalysed reactions for the synthesis of THPs with moderate yields, this protocol provided good to excellent yields. Application of these procedures produced three vanillic compounds reported here for the first time. Their structure was elucidated based on experimental and theoretical data (IR, 1H NMR, 13C NMR, NOESY, UV‐Vis, and DFT). Experimental and theoretical antioxidant evaluation of these compounds has been carried out. DFT thermodynamical parameters supported experimental results that newly synthesized THPs deserve considerable attention as potent radical scavengers.
Influence of Ionic Liquid Solvation on Various Size Homo‐ and Heterometallic Clusters [M’mMn] (M and M’= Au, Cu, Ag, Ni, Pd and Pt)
Authors: Pillegowda Manohar , Periyasamy Ganga
Published: December 2017

Solvent layer around nanoclusters(NCs) play an important role to control their shape, size and morphology along with physical and chemical properties. Solvent molecules interact with NCs either by forming strong bond or via weak interaction. Hence, to understand the binding mode of solvent towards nanoclusters become vital at microscopic level. In this regard, we have explored IL solvation on various nanoclusters using DFT based method. The computations show that metal clusters can be solvated without interfering their geometry using ionic liquid (IL) as solvent. The shape of the clusters defines the amount of ILs involved in binding. The anionic components of IL [OAc] have ability to form a strong bond, while cationic component [C1mim] bind through electrostatic interactions with metal cluster. Increase in size of the nanoclusters from [M2] to [M6] strengthen the binding mode of IL except in [M5] cluster, due to its geometry. Among, the cluster studied here [M6] interacts intensely with IL and forms delocalized orbital between metal cluster and IL. Further, the polarized heterometallic clusters have higher binding energy than the corresponding homo metallic cluster. Irrespective of composition, size and shape, the clusters studied in this work have been stabilized in IL with considerable amount of charge transfer from IL to metal cluster. Further, the calculated HOMO‐LUMO gaps indicate increase in chemical stability in IL environment.
The Discovery of the Effect of closo‐Borate on Amyloid Fibril Formation
Authors: Kuperman Marina , Chernii Svitlana , Varzatskii Oleg , Zhdanov Andrey , Bykov Alexander , Zhizhin Konstantin , Yarmoluk Sergiy , Kovalska Vladyslava
Published: December 2017

The activity of the boron cluster ‐ closo‐borates in protein amyloid fibrillization was first studied. For this, we explored the effect of dianionic compound [B12H12]2− on aggregation of amyloidogenic protein insulin by the circular dichroism spectroscopy, amyloid‐sensitive fluorescent dye based assay and transmission electron microscopy. It was shown that the presence of closo‐borate during fibrillization reaction speeds up the loss of the protein α‐helical structure. This effect of dianionic compound on protein fibrillization process is concentration‐dependent. Closo‐borate at low concentration (10 mM) enhances the intensity of insulin fibrillization, while at higher concentration (50 mM, 100 mM) fluorescent assay showed the decrease of this intensity. The morphology of fibrils formed in the presence of the boron dianion differs from that of free insulin, namely they are less branched and have the bigger diameter. Besides, closo‐borate‐induced fibrils have strong proneness to stick together forming large aggregated clots.
Role of Degree of Oxidation of Graphene Oxide on Biginelli Reaction Kinetics
Authors: Dhopte Kiran B. , Zambare Rahul S. , Patwardhan Anand V. , Nemade Parag R.
Published: December 2017

The effect of varying degree of oxidation of graphene oxide on its catalytic activity for synthesis of dihydropyrimidinones via Biginelli reaction is investigated. Graphene oxide with varying degree of oxidation (GO‐x) was synthesized, and characterized to confirm the change in functional groups on GO surface with different amount of oxidizing agent used during synthesis. An increase in amount of oxidant, increases the percentage of oxygen in GO‐x, increasing the d‐spacing and thus enhancing the exfoliation of GO‐x. The carboxylic acid groups increase with increasing oxidation degree, while the proportion of hydroxyl groups is almost the same. GO‐x shows excellent activity towards catalysing Biginelli reaction. An increase in oxygen content in GO‐x improves its catalytic activity, which is attributed to the increased acidity in GO‐x. Reaction kinetics imply a second order reaction. GO‐x shows excellent recyclability with only marginal loss in activity on recycle.
Fabrication of Porous Silicon Carbide Ceramics with High Electromagnetic Interference Shielding Effectiveness
Authors: Liu Chenyu , Qiu Zechao , Yu Dawei , Kirk Donald W. , Xu Yongjun
Published: December 2017

Porous SiC ceramics were synthesized for its potential electromagnetic interference (EMI) shielding application, with the utilization of a biomass material as the porous template and carbon precursor. A silicon infiltration process was conducted in the temperature range of 1400–1600 °C with the absence of any catalyst to produce the porous SiC ceramics. The porous SiC ceramics were characterized using scanning electron microscope, X‐ray diffraction and microwave vector network analyses. It was found that significantly higher EMI shielding effectiveness can be achieved using a higher silicon infiltration temperature. The porous SiC ceramics synthesized at 1600 °C possess the highest shielding value, reaching 60 dB at a high frequency range from 10 GHz to 18 GHz. It was proposed that the porous structure of the SiC can increase EM shielding performance by attenuating EM waves via multiple internal reflection and transmission of the incident and re‐reflected waves through the SiC walls of the porous network.
Light‐Driven Proton Release of Spirobenzopyran‐Derived Protonated Photomerocyanine in Cyclodextrin Aqueous Solution
Authors: Takeshita Tatsuya , Yano Atsushi , Hara Michihiro
Published: December 2017

Protonated photomerocyanine (PMCH), which is a ring‐opening isomer of spirobenzopyran, functions as a metastable‐state photoacid (PAH) driven by blue or visible light. Enhancement of the proton photodissociation efficiency and thermal stability of the deprotonated isomer facilitates pH adjustments and control by light irradiation. In this article, we report the proton photodissociation of PMCH based on 1,3,3‐trimethylindolino‐8’‐methoxybenzopyrylospiran (1) in an aqueous cyclodextrin (CD) solution. In the aqueous solution, the spirobenzopyran form of 1 underwent a spontaneous ring‐opening reaction and formed the thermodynamically stable PMCH form of 1 (PMCH‐1). After a laser flash at 355 nm, the photomerocyanine form of 1 (PMC‐1) was generated by proton photodissociation from the singlet excited state of PMCH‐1. The quantum yield of the proton photodissociation was changed by the stoichiometry or binding constant of the inclusion complex between PMCH‐1 and CD. Additionally, the encapsulation effects of CD inhibited the re‐protonation of PMC‐1. We conclude that these findings are useful for pH adjustment and control using PAHs based on PMCH.
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

The 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

Two 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

The 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

Mn 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

A 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

We 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

Herein, 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

A 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

An 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

Green 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

Recently, 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

An 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

Multi‐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

Conversion 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.