bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, Structures and Various Biological Applications of New Zn(II) Complexes Having Different Coordination Modes Controlled by the Drug Furosemide in Presence of Bioactive Nitrogen Based Ligands
Authors: Raymoni Ghana , Abu Ali Hijazi 
Published: December 2018

Novel Zn(II) complexes with the general formula: [Zn(furo)2(L)n], n = 1 or 2, (furo = furosemide = (4‐chloro‐2‐(furan‐2‐ylmethylamino)‐5‐sulfamoylbenzoic acid) were prepared. The complexes [Zn(furo)2(MeOH)2] (1; MeOH = methanol), [Zn(furo)2(2‐ampy)2] (2; 2‐ampy = 2‐aminopyridine), [Zn(furo)2(2‐ammepy)2] (3; 2‐ammepy = 2‐aminomethylpyridine), [Zn(furo)2(H2O)(2,2‐bipy)] (4; 2,2′‐bipy = 2,2′‐bipyridine), [Zn(furo)2(H2O)(4,4′‐bipy)] (5; 4,4′‐bipy = 4,4′‐bipyridine), [Zn(furo)2(1,10‐phen)] (6; 1,10‐phen = 1,10‐phenanthroline), [Zn(furo)2(2,9‐dmp)] (7; 2,9‐dmp = 2,9‐dimethyl‐1,10‐phenanthroline), and [Zn (furo)2(quin)2] (8; quin = quinoline) were synthesized and characterized using different techniques such as IR, UV–Vis, 1H NMR, 13C NMR, LC/MS and others. The crystal structure of complex (4) was determined using single‐crystal X‐ray diffraction.The anti‐bacterial activity of complexes (1–8) was tested using agar diffusion method against three gram‐positive (Staphylococcus aureus, Bacillus subtilis and Staphylococcus epidermidis) and three gram‐negative bacteria (Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa). The obtained results showed different Inhibition Zone Diameters (IZD) with various anti‐bacterial activities against the selected gram‐positive and gram‐negative bacteria.In addition, the rate of bis‐(4‐nitrophenyl) phosphate hydrolysis was measured at different temperatures, different pH values and different concentrations. The rates for the eight complexes were in the following order: complex 4 > 2 > 5 > 8 > 7 > 6 > 3 > 1.
Synthesis of propyl aminopyridine modified magnetite nanoparticles for cadmium (II) adsorption in aqueous solutions
Authors: Tajali Rad Fatemeh , Kefayati Hassan , Shariati Shahab 
Published: December 2018

In this study, 2‐aminopyridine functionalized magnetite nanoparticles were chemically synthesized and used for removing Cd2+ ions from aqueous solutions. The synthesized nanoparticles were characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis of X‐rays (EDX), thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM). The SEM results showed the synthesized magnetite nanoparticles have particle size around 26 nm. The effects of several variables including solution pH and volume, adsorbent mass, ionic strength and contact time on the Cd2+ adsorption were studied in batch experiments and finally the optimum conditions for adsorption were obtained. The kinetic data were investigated by pseudo‐ first‐order, pseudo‐ second‐order, intraparticle diffusion and Elovich kinetic models and data were described reasonably by pseudo‐ second‐order model (R2 = 0.9996) with qe = 2.31 mg g−1. Adsorption data were analyzed using Langmuir, Freundlich and Temkin isotherm models. The results indicated that the data were well fitted to the Freundlich isotherm model (R2 = 0.9907). After study the possible interference effect of foreign ions on Cd2+ removal, the applicability of the proposed nanoparticles for adsorption from real samples confirmed the successfully removal of Cd2+ ions with removal efficiency higher than 92%. The obtained results showed that the synthesized nanoparticles as a reusable adsorbent can act as a good choice for Cd2+ removal with an easy procedure.
Seeing and thinking in pictures: A review of visual information processing
Authors: Adaval Rashmi , Saluja Geetanjali , Jiang Yuwei 
Published: December 2018

AbstractConstructive and ecological theories of perception raise questions about whether visual perception is inherently data‐driven (bottom‐up) or interpreted in terms of higher‐order cognitions (top‐down). Analogies between these theoretical perspectives and the two visual systems involved in visual perception (the dorsal and ventral stream) suggest that the literature on visual information processing can be organized around two types of processes: object processing and spatial processing. Object processing involves the identification and recognition of stimuli in the environment and is shaped by existing concepts and associations in memory. It is associated with the processing of properties of objects such as color, size, shape, and pictorial details that are considered in this review. Spatial processing involves the perception of location, movement, spatial relations, and transformation of objects and other stimuli. Imagery‐based processes that are used to transform marketing stimuli in order to simulate various possibilities are reviewed in this section along with individual differences in spatial and visual abilities.
Effects of Substituents on Metastable‐State Photoacids: Design, Synthesis, and Evaluation of their Photochemical Properties
Authors: Liu Junning , Tang Wenqi , Sheng Lan , Du Zhen , Zhang Ting , Su Xing , Zhang Sean Xiao‐An 
Published: December 2018

AbstractRecently, metastable‐state photoacids have been widely used to control proton transfer in numerous chemical and biological processes as well as applications with visible light. Generally, substituents have a great influence on the photochemical properties of molecules, which will further affect their applications. Yet, the effects of substituents on metastable‐state photoacids have not been studied systematically. In this work, 16 metastable‐state photoacid derivatives were designed and synthesized on the basis of substituents having a large range of σ–π electron–donor–acceptor capabilities. The effects of substituents on the color display [or maximum absorption band(s)], solubility, pKa values, dark/photoacidity, photosensitivity, and relaxation kinetic(s) were investigated in detail. This study will be helpful for the targeted design and synthesis of promising photoacids and the application of their photocontrolled proton‐release processes in functional materials/devices.
Engineering Thermostable CYP2D Enzymes for Biocatalysis Using Combinatorial Libraries of Ancestors for Directed Evolution (CLADE)
Authors: Gumulya Yosephine , Huang Weiliang , D'Cunha Stephlina A. , Richards Katelyn E. , Thomson Raine E. S. , Hunter Dominic J. B. , Baek Jong‐Min , Harris Kurt L. , Boden M. , De Voss James J. , Hayes Martin A. , Isin Emre M. , Andersson Shalini , Jurva Ulrik , Gillam Elizabeth M. J. 
Published: December 2018

AbstractThe structure of metabolites of drug candidates must frequently be characterised during drug discovery and development. However, synthesising metabolites with the correct stereoselective modifications can be challenging for chemically complex parent compounds. Biocatalysis using human drug‐metabolising enzymes, such as cytochrome P450 2D6 (CYP2D6) is an alternative to chemical synthesis. However, most natural enzymes are unstable and have poor efficiency, limiting yields in preparative biotransformations. The aim of this study was to develop a library of robust mutant CYP2D enzymes for biocatalysis. The CLADE (combinatorial libraries of ancestors for directed evolution) approach increased the stability of CYP2D mutants obtained by DNA shuffling using three extant CYP2D forms. The resulting mutants showed divergent profiles of activity towards typical CYP2D substrates and included thermostable forms that may be useful for the further evolution of biocatalysts for specific applications.
Alkene Carboarylation through Catalyst‐Free, Visible Light‐Mediated Smiles Rearrangement
Authors: Whalley David M. , Duong Hung A. , Greaney Michael F. 
Published: December 2018

AbstractA light‐mediated Truce–Smiles arylative rearrangement is described that proceeds in the absence of any photocatalyst. The protocol creates two C−C bonds from simple starting materials, with the installation of an aryl ring and a difluoroacetate moiety across unactivated alkenes. The reaction proceeds via a radical mechanism, utilizing a light‐mediated reduction of ethyl bromodifluoroacetate by N,N,N′,N′‐tetramethylethylenediamine (TMEDA) to set up intermolecular addition to an unactivated alkene, followed by Truce–Smiles rearrangement.
Mo‐Based Oxidizers as Powerful Tools for the Synthesis of Thia‐ and Selenaheterocycles
Authors: Franzmann Peter , Beil Sebastian B. , Schollmeyer Dieter , Waldvogel Siegfried R. 
Published: December 2018

AbstractA highly efficient synthetic protocol for the synthesis of thia‐ and selenaheterocycles has been developed. By employing a MoCl5‐mediated intramolecular dehydrogenative coupling reaction, a broad variety of structural motifs was isolated in yields up to 94 %. The electrophilic key transformation is tolerated by several labile moieties like halides and tertiary alkyl groups. Due to the use of disulfide or diselenide precursors, a high atom efficiency was achieved.
2‐Fluoro‐1,3‐diamino‐4,6‐dinitrobenzene (ZXC‐7) and 2‐Fluoro‐1,3,5‐triamino‐4,6‐dinitrobenzene (ZXC‐8): Thermally Stable Explosives with Outstanding Properties
Authors: Zhang Zheng , Ma Jinchao , Zhou Qiuju , Hu Wenxiang , Zhang Xingcheng 
Published: December 2018

AbstractTwo novel, thermally stable explosives, 2‐fluoro‐1,3‐diamino‐4,6‐dinitrobenzene (ZXC‐7) and 2‐fluoro‐1,3,5‐triamino‐4,6‐dinitrobenzene (ZXC‐8), are reported. These two compounds can be prepared by means of simple synthetic methods and they show outstanding properties (detonation velocity, detonation pressure, sensitivity toward mechanical stimuli, and temperature of decomposition). Their structures are very similar to that of 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB). They were isolated and characterized by means of mass spectrometry and multinuclear (1H, 13C) NMR spectroscopy. The structure of ZXC‐7 in the crystalline state was determined by low‐temperature single‐crystal X‐ray diffraction. From the calculated standard molar enthalpy of formation (CBS‐4 M) and the densities (which were determined by a gas pycnometer), the Chapman‐Jouguet detonation properties were predicted by using the EXPLO5 V6.01 thermochemical computer code. The sensitivities of ZXC‐7 and ZXC‐8 towards impact and friction were determined.
Improving Quality, Reproducibility, and Usability of FRET‐Based Tension Sensors
Authors: Gates Evan M. , LaCroix Andrew S. , Rothenberg Katheryn E. , Hoffman Brenton D. 
Published: December 2018

AbstractMechanobiology, the study of how mechanical forces affect cellular behavior, is an emerging field of study that has garnered broad and significant interest. Researchers are currently seeking to better understand how mechanical signals are transmitted, detected, and integrated at a subcellular level. One tool for addressing these questions is a Förster resonance energy transfer (FRET)‐based tension sensor, which enables the measurement of molecular‐scale forces across proteins based on changes in emitted light. However, the reliability and reproducibility of measurements made with these sensors has not been thoroughly examined. To address these concerns, we developed numerical methods that improve the accuracy of measurements made using sensitized emission‐based imaging. To establish that FRET‐based tension sensors are versatile tools that provide consistent measurements, we used these methods, and demonstrated that a vinculin tension sensor is unperturbed by cell fixation, permeabilization, and immunolabeling. This suggests FRET‐based tension sensors could be coupled with a variety of immuno‐fluorescent labeling techniques. Additionally, as tension sensors are frequently employed in complex biological samples where large experimental repeats may be challenging, we examined how sample size affects the uncertainty of FRET measurements. In total, this work establishes guidelines to improve FRET‐based tension sensor measurements, validate novel implementations of these sensors, and ensure that results are precise and reproducible. © 2018 International Society for Advancement of Cytometry
Near‐optimal online routing in opportunistic networks
Authors: Arastouie Narges , Sabaei Masoud , Bakhshi Bahador 
Published: December 2018

SummaryIn opportunistic networks, nodes communicate intermittently based on store‐carry‐forward paradigm while exploiting node mobility. The challenge is to determine the ideal nodes to deliver the messages since there is no end‐to‐end connectivity. The nodes might make this decision based on the data sensed from the network. This technique is not ideal in scenarios where the speed of changes in the network topology is greater than the speed at which the nodes can collect info on the network, which might, in turn, be restricted due to usage constraints and uncertainty of knowledge about future contacts. To tackle the problems raised by the non‐deterministic environments, in this paper, a stochastic optimization model and corresponding algorithm are developed to find the optimal routes by considering the short and long‐term impact of choices, ie, the next hop. Herein, we first propose a stochastic model to resolve the routing problem by identifying the shortest path. In the second step, we show that the optimal solution of the proposed model can be determined in polynomial time. An online algorithm is then proposed and analyzed. The algorithm is O(lognρ) competitive considering the number of nodes and their associated energy. This model can take advantage of the unexpected meets to make the routing more elastic in a short time of contact and with less of a burden on the buffer. The simulation results, against the prominent algorithms, demonstrate significant improvement of the proposed approach in delivery and average delay ratio.
Facile in situ Electrosynthesis and High Electrocatalytic Performance of Interconnected Layered Double Hydroxides/Graphene Hybrids for Dopamine Oxidation: A Comparative Study
Authors: Kumar M. Kaleesh , Swaathini K. C. , Jha Niki S. , Jha Shailendra K. 
Published: December 2018

AbstractWe are reporting a facile in situ electrodeposition approach to prepare a rational design of M−Al (M: Ni, Co) layered double hydroxide (LDH)/reduced graphene oxide (G) hybrids and its superior electrocatalytic activity towards the electrooxidation of dopamine. Comparatively, the worm like interconnected nano‐chain networks of as‐prepared NiAl‐LDH/G hybrid modified electrode exhibits better performance than the CoAl‐LDH/G hybrid modified electrode. The enhanced electrocatalytic activity is because of its morphological evolution, which is due to its enhanced reduction rate, attachment pathway and incorporation or heterogeneous combination of Al3+ in the bimetallic LDHs/G hybrid. The satisfactory results are obtained for modified electrodes for the real‐time quantitative detection of dopamine in the real injectable medicine as well as human blood serum samples and it has also shown good reproducibility, stability and anti‐interference. This cost‐effective and facile in situ electrodeposition approach will give insights to design high performing hybrid materials and its application to non‐invasive electrochemical sensing which will be useful for daily diagnosis of neurological disorder.
Effects of chemical speciation on the bioaccessibility of zinc in spiked and smelter-affected soils
Authors: Elikem Essouassi , Laird Brian D. , Hamilton Jordan G. , Stewart Katherine J. , Siciliano Steven D. , Peak Derek 
Published: December 2018

Abstract

Previous studies have suggested that understanding soil metal speciation, rather than relying solely on total metal content, can improve the accuracy and utility of contaminated site risk assessments. Because soil properties and reaction time can alter metal speciation, speciation should influence metal bioaccessibility. For example, under gastrointestinal conditions, it is expected that metal species will differ in bioaccessibility depending on their stability in acidic pH environments. We studied the links between metal speciation and bioaccessibility. A combination of synchrotron-based X-ray diffraction and X-ray absorption near edge structure (XANES) was used to identify the zinc (Zn) speciation in spiked and smelter-affected soils. After conducting in vitro digestion tests on the soil samples, XANES and linear combination fitting were carried out on the residual pellets to identify the species of Zn that remained after digesting the soils in the simulated gastric and duodenal fluids. The metal species that were not present in the residual pellets were inferred to have been dissolved and, thus, more bioaccessible. Sphalerite (ZnS), ZnO, and outer-sphere Zn contributed more to Zn bioaccessibility than franklinite (ZnFe2O4) and Zn incorporated into a hydroxy interlayer mineral (Zn-HIM). The bioaccessibility of Zn-aluminum layered double hydroxides (Zn-Al-LDH) was found to be inversely proportional to its residence time in soil. It was also observed that the relatively high pH of the duodenum favors metal reprecipitation and readsorption, leading to a reduction in bioaccessible metal concentration. These results imply that metal speciation mainly controls metal bioaccessibility. Environ Toxicol Chem 2019;38:448–459. © 2018 SETAC.
Induction of maxillary and mandibular squamous epithelial cell proliferation in mink (Neovison vison) by β-naphthoflavone
Authors: Matz Danielle K. , Chuck Joanna , Hosmer Robin J. , Piper Hannah C. , Link Jane E. , Fitzgerald Scott D. , Steibel Juan P. , Bursian Steven J. 
Published: December 2018

Abstract

A jaw lesion reported in mink exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and TCDD-like chemicals is considered a potential indicator of exposure to these chemicals. Many of the effects of TCDD-like chemicals are induced through interaction with the aryl hydrocarbon receptor. The present study indicates that mink dosed with β-naphthoflavone, which is an aryl hydrocarbon receptor ligand but not a TCDD-like chemical, also develop the lesion. Environ Toxicol Chem 2019;38:460–463. © 2018 SETAC
Genomic instability in fragile sites—still adding the pieces
Authors: Irony‐Tur Sinai Michal , Kerem Batsheva 
Published: December 2018

AbstractCommon fragile sites (CFSs) are specific genomic regions in normal chromosomes that exhibit genomic instability under DNA replication stress. As replication stress is an early feature of cancer development, CFSs are involved in the signature of genomic instability found in malignant tumors. The landscape of CFSs is tissue‐specific and differs under different replication stress inducers. Nevertheless, the features underlying CFS sensitivity to replication stress are shared. Here, we review the events generating replication stress and discuss the unique characteristics of CFS regions and the cellular responses aimed to stabilizing these regions.
Potential of storing gas with high CO2 content in salt caverns built in ultra‐deep water in Brazil
Authors: Maia da Costa Alvaro , V. M da Costa Pedro , D. Udebhulu Okhiria , Cabral Azevedo Ricardo , F. F. Ebecken Nelson , C. O. Miranda Antonio , M. de Eston Sérgio , de Tomi Giorgio , R. Meneghini Julio , Nishimoto Kazuo , Ruggiere Felipe , Malta Edgard , Élis Rocha Fernandes Mauro , Brandão Camila , Breda Alexandre 
Published: December 2018

AbstractSalt caverns have been identified as one of the best options for the underground storage of gases due to salt rock's excellent sealing capabilities and interesting mechanical properties, such as self‐healing when damaged or cracked. It is feasible to build salt caverns in the Brazilian pre‐salt ultra‐deep water environment for gas storage. However, the peculiar geology of the Brazilian province considered here is characterized by the stratification of thick layers of halite with intercalations of carnallite and tachyhydrite salt rock, whose creep strain rate is almost two orders of magnitude higher than halite's creep strain rate under the same conditions of temperature and pressure. Computational mechanics is being used for the design of offshore salt caverns opened by dissolution mining for the storage of natural gas. The challenge presented in this paper requires the storage of natural gas with high CO2 content offshore in ultra‐deep water (2140 m) in salt caverns. If the economics proves feasible, this offshore gas storage station will be the first of its kind in the world. A technical feasibility rock mechanics study of giant salt caverns, 450 m high by 150 m in diameter, has shown that one cavern can store 4 billion Sm3 or 7.2 million tons of CO2. The salt dome studied can accommodate the construction of 15 caverns, thus providing the confinement of approximately 108 million tons of gas. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.
A Framework for Learning in the Chemistry Laboratory
Authors: Seery Michael K. , Agustian Hendra Y. , Zhang Xinchi 
Published: December 2018

AbstractDesigning laboratory activities is a real challenge for those working in higher education. There is often an acknowledged frustration with the status quo, but a lack of clear guidance on what strategies might be useful in considering a redesign. This article aims to address the question: what considerations should be taken into account when designing a laboratory activity? To address it, we first describe an overarching framework for laboratory learning, describing it as a complex learning environment. The reason for this is that two clear overarching guidelines emerge – the first is that the laboratory curriculum should be structured so that each new challenge for student is adequately supported by their prior learning so that they can draw on their knowledge to address the new learning situation, and the second is that guidelines for the kinds of preparation for laboratory learning emerge. Based on this framework, we advocate four core principles for laboratory learning that should be considered when designing a laboratory activity regarding the overall purpose, the role of preparation, the teaching of technique, and the consideration of affective dimensions of learning. We illustrate this framework in practice with examples from our own practice, with suggestions on using the literature on laboratory education as a source for curriculum reform within an institution.
Self‐Assembly of A Novel Ag48 Cluster Encapsulating an Unprecedented [Mo8O28]8− Anion Template
Authors: Wang Zhi , Zhuo Hong‐Yan , Hu An‐Yi , Su Hai‐Feng , Zhao Quan‐Qin , Wang Xing‐Po , Tung Chen‐Ho , Sun Di 
Published: December 2018

AbstractA novel silver cluster (SD/Ag48a) co‐protected by p‐MePhS− and CF3COO− ligands with an in‐situ generated unprecedented [Mo8O28]8− template has been synthesized under solvothermal condition. Single‐crystal X‐ray diffraction (SCXRD) and electrospray mass spectrometry (ESI‐MS) were used to determine the atom‐precise structure and solution behavior, respectively. Interestingly, the rare [Mo8O28]8− ion observed in the center of SD/Ag48a consists of 8 edge‐shared {MoO6} octahedra or can be deemed as three {Mo4O4} cubes fused together by sharing faces. The UV‐Vis spetcrum exhibits that a high‐energy (HE) wide absorption centered at ca. 365 nm, which can be assinged to intraligand (IL) π→π* transition absorption, whereas the low‐energy (LE) shoulder peak centered at ca. 500 nm can be ascribed to ligand‐to‐metal‐charge‐transfer (LMCT, S 3p→Ag 5 s) transition.