bluuebunny/crossref_metadata_2025 huggingface dataset:
Non‐Osmotic Hydrogels: A Rational Strategy for Safely Degradable Hydrogels
Authors: Kamata Hiroyuki , Kushiro Keiichiro , Takai Madoka , Chung Ung‐il , Sakai Takamasa
Published: June 2016

Hydrogels are promising materials for biomedical applications, where timely degradation is often preferred. In the conventional design, however, the cleavage of polymer networks essentially causes considerable morphological changes (i.e., degradation‐induced swelling), triggering various medical complications. Herein, we report a rational strategy to suppress the degradation‐induced swelling based on the synthetic control of the polymer–solvent interaction parameter (χ) of constituent polymer networks. The resultant hydrogels with an optimal χ parameter (χ37 °C≈0.53; non‐osmostic hydrogels) displayed the capability to retain their original shape and degrade without generating significant swelling pressure under physiological conditions (Π37 °C<1 kPa). This concept of the safely degradable non‐osmotic hydrogel is theoretically universal, and can be exploited for other types of synthetic hydrogels in various settings.
Solvent Extraction: Structure of the Liquid–Liquid Interface Containing a Diamide Ligand
Authors: Scoppola Ernesto , Watkins Erik B. , Campbell Richard A. , Konovalov Oleg , Girard Luc , Dufrêche Jean‐Francois , Ferru Geoffroy , Fragneto Giovanna , Diat Olivier
Published: June 2016

Knowledge of the (supra)molecular structure of an interface that contains amphiphilic ligand molecules is necessary for a full understanding of ion transfer during solvent extraction. Even if molecular dynamics already yield some insight in the molecular configurations in solution, hardly any experimental data giving access to distributions of both extractant molecules and ions at the liquid–liquid interface exist. Here, the combined application of X‐ray and neutron reflectivity measurements represents a key milestone in the deduction of the interfacial structure and potential with respect to two different lipophilic ligands. Indeed, we show for the first time that hard trivalent cations can be repelled or attracted by the extractant‐enriched interface according to the nature of the ligand.
Enantio‐ and Diastereoselective 1,2‐Additions to α‐Ketoesters with Diborylmethane and Substituted 1,1‐Diborylalkanes
Authors: Murray Stephanie A. , Green Jacob C. , Tailor Sanita B. , Meek Simon J.
Published: June 2016

The catalytic enantioselective synthesis of boronate‐substituted tertiary alcohols through additions of diborylmethane and substituted 1,1‐diborylalkanes to α‐ketoesters is reported. The reactions are catalyzed by readily available chiral phosphine/copper(I) complexes and produce β‐hydroxyboronates containing up to two contiguous stereogenic centers in up to 99:1 e.r. and greater than 20:1 d.r. The utility of the organoboron products is demonstrated through several chemoselective functionalizations. Evidence indicates the reactions occur via an enantioenriched α‐boryl‐copper‐alkyl intermediate.
Redox‐Active‐Ligand‐Mediated Formation of an Acyclic Trinuclear Ruthenium Complex with Bridging Nitrido Ligands
Authors: Bagh Bidraha , Broere Daniël L. J. , Siegler Maxime A. , van der Vlugt Jarl Ivar
Published: June 2016

Coordination of a redox‐active pyridine aminophenol ligand to RuII followed by aerobic oxidation generates two diamagnetic RuIII species [1 a (cis) and 1 b (trans)] with ligand‐centered radicals. The reaction of 1 a/1 b with excess NaN3 under inert atmosphere resulted in the formation of a rare bis(nitrido)‐bridged trinuclear ruthenium complex with two nonlinear asymmetrical Ru‐N‐Ru fragments. The spontaneous reduction of the ligand centered radical in the parent 1 a/1 b supports the oxidation of a nitride (N3−) to half an equivalent of N2. The trinuclear omplex is reactive toward TEMPO‐H, tin hydrides, thiols, and dihydrogen.
Selection of thinner for epoxy–amine system used as binder for polymeric mortars
Authors: Bourguiba Amal , Dhaoui Wadia , Ghorbel Elhem
Published: June 2016

Epoxy resin mortars are mainly used in the implementation of precast items used in the civil engineering field. The workability of these mortars represents a major obstacle to the development of this field. In order to improve this property, different types of thinners are selected to study their effect on the rheological properties of the epoxy–amine system. Rheological tests are performed in order to estimate the resin gel point and to measure its viscosity during the crosslinking reaction. It appears that viscosity is the lowest for mixtures prepared with methyl octanoate, o‐xylene, and butyl glycidyl ether. Methyl octanoate is chosen as an ecofriendly thinner. The curing process is evaluated by varying the amount of the selected thinner using isothermal and dynamic DSC to determine the end of crosslinking. The mechanical properties using dynamic mechanical analysis (DMA) and tensile resistance testing of the cured epoxy resin with different amounts of methyl octanoate are also investigated. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43970.
Electrofishing as a new method to search for unknown populations of the endangered freshwater pearl mussel Margaritifera margaritifera
Authors: Salonen Jouni K. , Taskinen Jouni
Published: June 2016

1. The freshwater pearl mussel Margaritifera margaritifera is threatened throughout its Holarctic range, but the occurrence of this species is insufficiently mapped. For the conservation of M. margaritifera, it is important to identify populations more comprehensively.

2. Traditionally mussels have been searched for visually using techniques such as diving and aquascope, both of which are potentially time‐consuming and demanding survey methods.

3. In this study, a new search method is presented. As glochidia of M. margaritifera are larval parasites on the gills of salmonid fish, electrofishing and non‐destructive examination of salmonids with the naked eye may reveal the presence of glochidia and therefore the occurrence of M. margaritifera in watercourses. This method was tested in both the field and laboratory in northern Finland.

4. In summer, when M. margaritifera glochidia were large, the status of salmonids being infected or uninfected by M. margaritifera was correctly identified with the naked eye with 62, 80, 88 and 93% accuracy in four streams sampled, 96% accuracy in the laboratory, and 100% accuracy in all cases when at least 20 glochidia per fish were present. Intensity of infection was also assessed successfully; a specifically tailored, qualitative abundance score correlated significantly with the real number of glochidia. However, during autumn with small glochidia freshly attached to fish, glochidia infection could be observed only under microscopic examination.

5. When the method was used in 40 previously incompletely surveyed tributaries, three M. margaritifera populations were found. The infection in salmonids was observed always with the naked eye, being subsequently confirmed microscopically. The existence of adult mussels in two of these rivers was also confirmed.

6. The results indicate that electrofishing and a relatively quick naked‐eye check of salmonids provides a new, non‐destructive, and potentially cost‐effective way to search for new, previously unrecorded M. margaritifera populations. Copyright © 2016 John Wiley & Sons, Ltd.
Novel Aldimine‐Type Schiff Bases of 4‐Amino‐5‐[(3,4,5‐trimethoxyphenyl)methyl]‐1,2,4‐triazole‐3‐thione/thiol: Docking Study, Synthesis, Biological Evaluation, and Anti‐Tubulin Activity
Authors: Ameri Alieh , Khodarahmi Ghadamali , Hassanzadeh Farshid , Forootanfar Hamid , Hakimelahi Gholam‐Hosein
Published: June 2016

The present study was planned to design some novel aldimine‐type Schiff bases bearing 3,4,5‐trimethoxyphenyl and 1,2,4‐triazole‐3‐thione/thiol as potential tubulin polymerization inhibitors. The obtained results of the molecular docking study using the tubulin complex (PDB code: 1SA0) showed that compounds H‐25 and H‐26 were well fitted in the colchicine binding site of tubulin with binding energies of −8.68 and −8.40 kcal/mol, respectively, in comparison to the main ligand (−8.20 kcal/mol). In parallel, molecular simulations were also performed on five other 3,4,5‐trimethoxyphenyl‐containing ligand targets including hsp90, VEGFR2, and human and microbial (Staphylococcus aureus and Candida albicans) dihydrofolate reductase, among which H‐17, H‐45, H‐27, H‐02, and H‐19 were the most suitable compounds, respectively. Evaluation of the cytotoxic effect of the most efficient compounds of the docking steps (H‐25) revealed IC50 values of 12.48 ± 1.10, 4.25 ± 0.22, 3.33 ± 0.31, and 9.71 ± 0.75 µM against the HT1080, HT29, MCF‐7, and A549 cell lines, respectively, compared to doxorubicin (12.69 ± 1.23, 6.12 ± 0.47, 3.51 ± 0.32, and 6.40 ± 0.31 µM, respectively). The in vitro tubulin polymerization investigation launched compounds H‐25 and H‐26 as potent antitubulin agents due to their IC50 values of 0.17 ± 0.01 and 10.93 ± 0.43 µM, respectively.
Psychophysiological Associations with Gastrointestinal Symptomatology in Autism Spectrum Disorder
Authors: Ferguson Bradley J. , Marler Sarah , Altstein Lily L. , Lee Evon Batey , Akers Jill , Sohl Kristin , McLaughlin Aaron , Hartnett Kaitlyn , Kille Briana , Mazurek Micah , Macklin Eric A. , McDonnell Erin , Barstow Mariah , Bauman Margaret L. , Margolis Kara Gross , Veenstra‐VanderWeele Jeremy , Beversdorf David Q.
Published: June 2016

Autism spectrum disorder (ASD) is often accompanied by gastrointestinal disturbances, which also may impact behavior. Alterations in autonomic nervous system functioning are also frequently observed in ASD. The relationship between these findings in ASD is not known. We examined the relationship between gastrointestinal symptomatology, examining upper and lower gastrointestinal tract symptomatology separately, and autonomic nervous system functioning, as assessed by heart rate variability and skin conductance level, in a sample of 120 individuals with ASD. Relationships with co‐occurring medical and psychiatric symptoms were also examined. While the number of participants with significant upper gastrointestinal tract problems was small in this sample, 42.5% of participants met criteria for functional constipation, a disorder of the lower gastrointestinal tract. Heart rate variability, a measure of parasympathetic modulation of cardiac activity, was found to be positively associated with lower gastrointestinal tract symptomatology at baseline. This relationship was particularly strong for participants with co‐occurring diagnoses of anxiety disorder and for those with a history of regressive ASD or loss of previously acquired skills. These findings suggest that autonomic function and gastrointestinal problems are intertwined in children with ASD; although it is not possible to assess causality in this data set. Future work should examine the impact of treatment of gastrointestinal problems on autonomic function and anxiety, as well as the impact of anxiety treatment on gastrointestinal problems. Clinicians should be aware that gastrointestinal problems, anxiety, and autonomic dysfunction may cluster in children with ASD and should be addressed in a multidisciplinary treatment plan. Autism Res 2017, 10: 276–288. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.
The Discovery of New Human Coagulation Factor XIa (FXIa) Inhibitors by Synthesis, Biological Evaluation, and Structure‐based Modeling
Authors: Lee Myeong Hwi , Song Ho Young , Kim Hyoungrae , Park Kyung Eun , Kim Jinyeong , Park Tae Kyo , Kim Yong Ju , Kang Nam Sook
Published: June 2016

Factor XIa (FXIa) is an enzyme that is activated during the earliest stage of initiation of the intrinsic pathway of the blood coagulation mechanism. In this study, we attempted to discover a new FXIa inhibitor based on structure‐based molecular modeling. We found that compound 16 exhibits satisfactory predicted properties while maintaining important binding interactions with FX1a.
1,8‐Naphthalimide Derivative Dyes with Large Stokes Shifts for Targeting Live‐Cell Mitochondria
Authors: Zhang Liqiang , Su Fengyu , Kong Xiangxing , Lee Fred , Sher Steven , Day Kevin , Tian Yanqing , Meldrum Deirdre R.
Published: June 2016

An ideal fluorescent dye for staining cell organelles should have multiple properties including specificity, stability, biocompatibility, and a large Stokes shift. Tunable photophysical properties enable 1,8‐naphthalimide to serve as an excellent fluorophore in biomedical applications. Many naphthalimide derivatives have been developed into drugs, sensors, and other dyes. In this study, a series of 1,8‐naphthalimide derivatives targeting live cell mitochondria were synthesized. Among these probes, Mt‐4 was characterized as the best one, with highly specific mitochondrial localization, low cytotoxicity, and a large Stokes shift. More importantly, Mt‐4 stood out as a potential mitochondrial dye for living‐cell experiments involving induced mitochondrial stress arising from the treatments because Mt‐4 shows enhanced fluorescence in mitochondrial stress situations.
A Series of Diamagnetic Pyridine Monoimine Rhenium Complexes with Different Degrees of Metal‐to‐Ligand Charge Transfer: Correlating 13C NMR Chemical Shifts with Bond Lengths in Redox‐Active Ligands
Authors: Sieh Daniel , Kubiak Clifford P.
Published: June 2016

A set of pyridine monoimine (PMI) rhenium(I) tricarbonyl chlorido complexes with substituents of different steric and electronic properties was synthesized and fully characterized. Spectroscopic (NMR and IR) and single‐crystal X‐ray diffraction analyses of these complexes showed that the redox‐active PMI ligands are neutral and that the overall electronic structure is little affected by the choices of the substituent at the ligand backbone. One‐ and two‐electron reduction products were prepared from selected starting compounds and could also be characterized by multiple spectroscopic methods and X‐ray diffraction. The final product of a one‐electron reduction in THF is a diamagnetic metal–metal‐bonded dimer after loss of the chlorido ligand. Bond lengths in and NMR chemical shifts of the PMI ligand backbone indicate partial electron transfer to the ligand. Two‐electron reduction in THF also leads to the loss of the chlorido ligand and a pentacoordinate complex is obtained. The comparison with reported bond lengths and 13C NMR chemical shifts of doubly reduced free pyridine monoaldimine ligands indicates that both redox equivalents in the doubly reduced rhenium complex investigated here are located in the PMI ligand. With diamagnetic complexes varying over three formal reduction stages at the PMI ligand we were, for the first time, able to establish correlations of the 13C NMR chemical shifts with the relevant bond lengths in redox‐active ligands over a full redox series.
Synthesis of Boronate‐Based Benzo[fg]tetracene and Benzo[hi]hexacene via Demethylative Direct Borylation
Authors: Numano Misa , Nagami Naoto , Nakatsuka Soichiro , Katayama Takazumi , Nakajima Kiichi , Tatsumi Sou , Yasuda Nobuhiro , Hatakeyama Takuji
Published: June 2016

A demethylative direct borylation is reported, which was applied to the synthesis of benzo[fg]tetracenes containing boronate ester, amide, and thioester substructures. Depending on the heteroatom adjacent to boron, the molecules showed characteristic photophysical properties, molecular arrangements, and chemical stabilities. The key to the successful synthesis is the appropriate choice of the boron source and Brønsted base. The versatility of the direct borylation was demonstrated by the synthesis of a boronate‐based benzo[hi]hexacene.
Impact of specific patterns on the sensitivity for follicular and Hurthle cell carcinoma in thyroid fine‐needle aspiration
Authors: Renshaw Andrew A. , Gould Edwin W.
Published: June 2016

BACKGROUND

To the authors' knowledge, the impact of specific cytologic patterns in thyroid fine‐needle aspiration (FNA) for follicular and Hurthle cell carcinoma is not known.

METHODS

The results of all thyroid FNAs performed from 1997 through 2015 with corresponding resections of follicular and Hurthle cell carcinomas were reviewed.

RESULTS

A total of 24 follicular carcinomas and 35 Hurthle cell carcinomas were identified. All FNA specimens from follicular carcinomas had a microfollicular component (3 of which were noted only in 3‐dimensional groups), but only 18 cases (75%) had cytologic atypia, which most commonly consisted of enlarged nuclei with slightly pale chromatin. Diagnosing cases without cytologic atypia as benign would significantly decrease the sensitivity of the test (P = .02). Five Hurthle cell FNA specimens consisted of only scant Hurthle cells. The remaining Hurthle cell FNA specimens could be divided into those with large cell dysplasia (15 cases), those with small cell dysplasia (10 cases), cases with anisonucleosis insufficient for a diagnosis of large cell dysplasia (4 cases), and cases with Hurthle cells in flat sheets without atypia (1 case). Diagnosing cases with flat sheets without atypia as benign did not appear to affect the sensitivity of the test (P = 1.00).

CONCLUSIONS

Diagnosing FNA specimens with microfollicles without atypia as benign appears to significantly reduce the sensitivity for follicular carcinoma to 75%; in contrast, diagnosing FNA specimens with Hurthle cells in flat sheets without anisonucleosis as benign does not. Cancer Cytopathol 2016;124:729–36. © 2016 American Cancer Society.
Using DrugBank for In Silico Drug Exploration and Discovery
Authors: Wishart David S. , Wu Anthony
Published: June 2016

DrugBank is a fully curated drug and drug target database that contains 8174 drug entries including 1944 FDA approved small‐molecule drugs, 198 FDA‐approved biotech (protein/peptide) drugs, 93 nutraceuticals, and over 6000 experimental drugs. Additionally, 4300 non‐redundant protein (i.e., drug target/enzyme/transporter/carrier) sequences are linked to these drug entries. DrugBank is primarily focused on providing both the query/search tools and biophysical data needed to facilitate drug discovery and drug development. This unit provides readers with a detailed description of how to effectively use the DrugBank database and how to navigate through the DrugBank Web site. It also provides specific examples of how to find chemical homologs of potential drug leads and how to identify potential drug targets from newly sequenced tumor samples. The intent of this unit is to give readers an introduction to the field of Web‐based drug discovery and to show how cheminformatics can be seamlessly integrated into the field of bioinformatics. © 2016 by John Wiley & Sons, Inc.
Inference of Episodic Changes in Natural Selection Acting on Protein Coding Sequences via CODEML
Authors: Bielawski Joseph P. , Baker Jennifer L. , Mingrone Joseph
Published: June 2016

This unit provides protocols for using the CODEML program from the PAML package to make inferences about episodic natural selection in protein‐coding sequences. The protocols cover inference tasks such as maximum likelihood estimation of selection intensity, testing the hypothesis of episodic positive selection, and identifying sites with a history of episodic evolution. We provide protocols for using the rich set of models implemented in CODEML to assess robustness, and for using bootstrapping to assess if the requirements for reliable statistical inference have been met. An example dataset is used to illustrate how the protocols are used with real protein‐coding sequences. The workflow of this design, through automation, is readily extendable to a larger‐scale evolutionary survey. © 2016 by John Wiley & Sons, Inc.
Studying RNA Homology and Conservation with Infernal: From Single Sequences to RNA Families
Authors: Barquist Lars , Burge Sarah W. , Gardner Paul P.
Published: June 2016

Emerging high‐throughput technologies have led to a deluge of putative non‐coding RNA (ncRNA) sequences identified in a wide variety of organisms. Systematic characterization of these transcripts will be a tremendous challenge. Homology detection is critical to making maximal use of functional information gathered about ncRNAs: identifying homologous sequence allows us to transfer information gathered in one organism to another quickly and with a high degree of confidence. ncRNA presents a challenge for homology detection, as the primary sequence is often poorly conserved and de novo secondary structure prediction and search remain difficult. This unit introduces methods developed by the Rfam database for identifying “families” of homologous ncRNAs starting from single “seed” sequences, using manually curated sequence alignments to build powerful statistical models of sequence and structure conservation known as covariance models (CMs), implemented in the Infernal software package. We provide a step‐by‐step iterative protocol for identifying ncRNA homologs and then constructing an alignment and corresponding CM. We also work through an example for the bacterial small RNA MicA, discovering a previously unreported family of divergent MicA homologs in genus Xenorhabdus in the process. © 2016 by John Wiley & Sons, Inc.
Size‐Dependence of the Activity of Gold Nanoparticle‐Loaded Titanium(IV) Oxide Plasmonic Photocatalyst for Water Oxidation
Authors: Teranishi Miwako , Wada Masataka , Naya Shin‐ichi , Tada Hiroaki
Published: June 2016

Mesoporous TiO2 nanocrystalline film was formed on fluorine‐doped tin oxide electrode (TiO2/FTO) and gold nanoparticles (NPs) of different sizes were loaded onto the surface with the loading amount kept constant (Au/TiO2/FTO). Visible‐light irradiation (λ>430 nm) of the Au/TiO2/FTO photoanode in a photoelectrochemical cell with the structure of photoanode|0.1 m NaClO4 aqueous solution|Ag/AgCl (reference electrode)|glassy carbon (cathode) leads to the oxidation of water to oxygen (O2). We show that the visible‐light activity of the Au/TiO2/FTO anode increases with a decrease in Au particle size (d) at 2.9≤d≤11.9 nm due to the enhancement of the charge separation and increasing photoelectrocatalytic activity.
Metal‐Dependent Nucleobase Recognition by Picolinamide
Authors: Dengale Rohit A. , Thopate Shankar R. , Lönnberg Tuomas
Published: June 2016

A C‐nucleoside featuring picolinamide as the base moiety has been synthesized and incorporated in the middle of a DNA oligonucleotide. The melting temperatures of duplexes formed by this modified oligonucleotide with its unmodified counterparts placing either adenine, cytosine, guanine or thymine opposite to the picolinamide residue were found to be highly dependent on the identity and concentration of transition metal ions in the samples. For example, AgI uniquely promoted pairing with adenine and PdII with guanine. Pairing with cytosine, on the other hand, was retarded by all of the metal ions studied (AgI, CuII, HgII, NiII, PdII and ZnII).
Surfactant directed synthesis of mesoporous alumina and α‐alumina single crystal
Authors: Mishra Geetanjali , Dash Barsha , Dash Ajit , Bhattacharya I.N.
Published: June 2016

Mesoporous Al2O3 were positively synthesized via treatment of the freshly precipitated amorphous alumina gel using aluminium sulphate as aluminium source, and sodium dodecyl sulphate (SDS) as structure‐directing agent (SDAs). The microstructures, morphologies and textural properties of the as‐prepared materials were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM) and thermo gravimetric analysis (TG‐DTA). The calcined product at 600 °C was highly porous in nature having a BET surface area of 42 m2/g. These porous Al2O3 exhibits excellent adsorption performance for Congo red and the corresponding decolourisation efficiencies reached 99% in just 15 min at 27 °C. The subsequent calcined product at 1200 °C is the alpha alumina single crystal hexagonal platelets with rhombohedral crystallization.
A Power Output Estimate of Cylindrically Shaped Flexible Photovoltaic Module with Polygonal Approximation
Authors: SHIBASAKI MAMORU , YACHI TOSHIAKI
Published: June 2016

Flexible photovoltaic (PV) modules have received a great deal of attention for use in PV systems. At present, the most important issue to be resolved is the optimum shape of flexible PV modules for obtaining maximum power output. A design tool specifically tailored for the flexible PV module is required for this purpose. In the present study, a new method is proposed for estimating the power output of a cylindrically shaped flexible PV module, taking into account the uneven irradiation and temperature that occurs for a curved surface. The average irradiation over the area of the entire module is used in the equation of the proposed method. The temperature is calculated based on the root mean square (RMS) of the irradiation over the area of the entire module. The average and RMS of the irradiation are calculated based on the directional dependence of the global horizontal irradiance. The estimated and measured power outputs are compared. The error rate of the total power output is 2.6%, and the mean absolute percentage error of the power output is 6.8%. The proposed method can reduce the amount of calculation to compare with a conventional method having the same mean absolute percentage error.
An Investigation of Size‐Reduction Effects in High Power Density Boost Converters with a Magnetic Coupling
Authors: AOTO SHOGO , KIMURA SHOTA , IMAOKA JUN , YAMAMOTO MASAYOSHI
Published: June 2016

The dc–dc converter using integrated magnetic components that may achieve high power density has gained attention in environmentally friendly cars such as electric vehicles and hybrid electric vehicles. This paper focused on interleaved boost converters using close‐coupled inductors (CCIs) and loose‐coupled inductors (LCIs) that are the integrated magnetic components. Following, detailed electromagnetically analysis for these circuit types were conducted in order to calculate volume of inductors and capacitors that are occupied the large part of space in the converters. The total volume of inductors and capacitors in these circuits were demonstrated clearly through comparison with conventional circuits such as an interleaved boost converter and a single‐phase boost converter. As a result, it became clear that interleaved boost converter using LCIs was effective for miniaturization of total volume. Furthermore, duty ratio of the minimum volume of CCI method is different from the duty ratio of the minimum volume of LCI method.
Microporous Metal–Organic Frameworks Based on Zinc Clusters and Their Fluorescence Enhancements towards Acetone and Chloroform
Authors: Wang Kangcai , Lin Zhien , Huang Shi , Sun Jie , Zhang Qinghua
Published: June 2016

Two microporous metal–organic frameworks (MOFs) based on zinc clusters, that is, [Zn3(BDC)2(HBDC)2]·2DMA·4CH3OH·2H2O (1; H2BDC = 1,4‐dicarboxybenzene, DMA = N,N‐dimethylacetamide) and [(CH3)2NH2]2[Zn7(µ4‐O)2(NDC)6]·DMF·H2O (2; H2NDC = 1,4‐naphthalenedicarboxylic acid, DMF = N,N‐dimethylformamide), were synthesized by a solvothermal method. Both compounds possess three‐dimensional porous skeletons with square channels and exhibit interesting blue fluorescence. Compound 1 consists of trinuclear ZnII building units bridged by both BDC2– and HBDC– ligands, which results in the formation of a 2,8‐connnected topological net (hex). Compound 2 features another 2,8‐connected topological net (bcu) that is constructed by eight‐connected Zn7(µ4‐O)2 clusters and two‐connected NDC2– ligands. The solid‐state and solvent‐dependent fluorescence of the two MOFs revealed that 1 and 2 showed fluorescence enhancement effects in the presence of acetone and chloroform, respectively, which thereby demonstrates their potential as fluorescent sensors for selective sensing towards acetone and chloroform.
A Size‐Dependent Analysis of the Structural, Surface, Colloidal, and Thermal Properties of Ti1–xB2 (x = 0.03–0.08) Nanoparticles
Authors: Terlan Bürgehan , Levin Aleksandr A. , Börrnert Felix , Zeisner Julian , Kataev Vladislav , Schmidt Marcus , Eychmüller Alexander
Published: June 2016

We report the size‐dependent structural, surface, colloidal, and thermal properties of the well‐known refractory material titanium diboride prepared at the nanoscale by a size‐controlled inorganic molten‐salt technique. A combined analysis of the powder X‐ray diffraction data through a modified Williamson–Hall plot, a size–strain plot, and Rietveld fitting methods indicates that TiB2 nanocrystals with average crystallite sizes smaller than D ≈ 22 nm prefer to form defects at the titanium site rather than experience strain. The resulting composition is Ti1–xB2 [x = 0.03(1)–0.08(1)]. The size‐induced defect formation is accompanied by anisotropic lattice contraction that decreases primarily the cell parameter c. Transmission electron microscopy revealed that the nanocrystals are embedded in an amorphous matrix. A comparison between the electron spin resonance spectra of bulk and nanosized samples indicated that only the nanosized samples yield observable signals. This signal is associated with unpaired electrons trapped in the boron–oxygen species that surround the Ti1–xB2 nanocrystals. These species provide stability to the Ti1–xB2 nanocrystals in aqueous dispersions, as evidenced by electrokinetic measurements. Upon heating under an Ar atmosphere, the boron–oxygen species evaporate from ca. 1000 °C, and the Ti vacancies in the interior nanocrystalline core vanish. TiB2 nanocrystals show excellent chemical stability against decomposition up to 1500 °C.
A Computational Approach to Predicting Ligand Selectivity for the Size‐Based Separation of Trivalent Lanthanides
Authors: Ivanov Alexander S. , Bryantsev Vyacheslav S.
Published: June 2016

Reprocessing of high‐level waste is a key step in advancing sustainable energy systems. The development of efficient chelating agents for trivalent f‐block metal ions is essential for increasing the efficiency of nuclear‐waste remediation and extractive hydrometallurgy of rare‐earth elements. Although computer‐aided screening could lead to a more rapid discovery of superior ligands, an accurate theoretical description of the solvation effects for trivalent metal ions is currently a stumbling block in qualitative predictions for selectivity trends along the lanthanide series. In this work, we propose a robust model to describe the differential effect of solvation in the competitive binding of a ligand with lanthanides by including weakly coordinated counterions in the complexes of more than a +1 charge. The success of this approach in quantitatively reproducing aqueous selectivities demonstrates its potential for the design and screening of new ligands for efficient size‐based separation.
10000‐Fold Enhancement in Proton Conduction by Doping of Cesium Ions in a Proton‐Conducting Zwitterionic Metal–Organic Framework
Authors: Shalini Sorout , Aggarwal Shubhangi , Singh Santosh K. , Dutt Malvika , Ajithkumar Thallaseril G. , Vaidhyanathan Ramanathan
Published: June 2016

Developing metal–organic framework (MOF)‐based proton‐conducting electrolytes for fuel‐cell applications is an important target that has drawn a lot of attention. A key approach involves the selective replacement of the guest species within the pores to enhance performance. The modular and crystalline nature of the MOF permits controlled introduction of such species and characterization of their compositions with high precision, a task which is very difficult to achieve in amorphous polymers. Herein, we partially replaced the protons of a zwitterionic pyridinol in Mg(terephthalate)(pyridinol) MOF 1 with Cs+ ions, which brought about a 10000‐fold increase in the proton conductivity (10–6 to 10–2 S cm–1). Interestingly, Li+ ions could not be loaded, whereas Cs+ ions with smaller hydrated ionic radii could be loaded, and the loading was controlled as a function of time. The Cs+ loading nearly halved the activation energy (from 0.35 for 1 to 0.19 eV for 1_Cs). The highest conductivities were realized for an optimal loading of Cs+ ions, which was found to be about 10 % in this case.
Tandem Demethylation/Annulation/Oxidation of 2,3‐Bis(2‐methoxyphenyl)‐3‐oxopropanals for One‐Pot Construction of Coumestans
Authors: Zhang Jiefeng , Qiu Jiakun , Xiao Chunmei , Yu Lifang , Yang Fan , Tang Jie
Published: June 2016

A convenient and practical approach to coumestans has been successfully developed by using a one‐pot tandem demethylation/annulation/oxidation reaction sequence that employs easily accessible 2,3‐bis(2‐methoxyphenyl)‐3‐oxopropanals as the starting material. This synthetic protocol provided a variety of coumestan derivatives in good to excellent yields under mild conditions. The exploration of biologically active coumestan compounds is a potential application of this synthetic method.
Transition‐Metal‐Catalyzed Acyloxylation: Activation of C(sp2)–H and C(sp3)–H Bonds
Authors: Moghimi Setareh , Mahdavi Mohammad , Shafiee Abbas , Foroumadi Alireza
Published: June 2016

In this review we present recent advances in C–H bond activation for transition‐metal‐catalyzed acyloxylation. This activation is a powerful method for the construction of C–O bonds in diverse compounds. Directed and non‐directed approaches are covered, with the emphasis on the role of directing groups in these transformations.
The Organocatalytic α‐Fluorination of Chiral γ‐Nitroaldehydes: the Challenge of Facing the Construction of a Quaternary Fluorinated Stereocenter
Authors: Emma Marco Giuseppe , Lombardo Marco , Trombini Claudio , Quintavalla Arianna
Published: June 2016

Chiral γ‐nitroaldehydes 1 are easily accessible by the organocatalytic Michael addition of aldehydes to nitroalkenes. In this paper, we report the organocatalytic fluorination of 1 with N‐fluorobenzenesulfonimide (NFSI) leading to the highly stereoselective construction of a challenging quaternary fluorinated stereocenter at the α position of α,α‐dialkyl aldehydes. The reaction takes place via a chiral trisubstituted enamine, so far rather unexplored in the field of organocatalysis. Fluorinated products 3 are direct precursors of chiral monofluorinated 3,4‐polysubstituted pyrrolidines. Mechanistic details are discussed with the aid of computational results.
Allostery in Guest Binding of Rim‐to‐Rim‐Connected Homoditopic Biscavitands
Authors: Shimoyama Daisuke , Yamada Hitomi , Ikeda Toshiaki , Sekiya Ryo , Haino Takeharu
Published: June 2016

Rim‐to‐rim‐connected phosphonate biscavitands 1a and 1b were synthesized. Crystal structure analysis and variable‐temperature NMR spectroscopy studies reveal that 1a is more rigid in conformation than 1b. Biscavitands 1a and 1b bind cationic guests G1–G3 through hydrogen bonding and CH–π interactions, demonstrating positive and negative allosteric effects, respectively. The allosteric effects in guest binding are associated with the conformational flexibilities of 1a and 1b. The positive allosteric effect of 1a is directed by the tightly connected cavities, in which information of the first guest binding is transferred to the remaining cavity, which becomes preorganized. In contrast, a slightly negative allosteric effect is found in more‐flexible 1b.
Hydrogen‐Bonding Network Anchors the Cyclic Form of Sugar Arylhydrazones
Authors: Goldschmidt Gőz Viktória , Pintér István , Csámpai Antal , Jákli Imre , Zsoldos‐Mády Virág , Perczel András
Published: June 2016

The “classical” challenge, raised by Emil Fischer as to why one monosaccharide arylhydrazone adopts a cyclic structure but another an acyclic structure, is answered here. The present comprehensive analysis of hexose and hexosamine arylhydrazones, based on 2D NMR spectroscopy and theoretical modeling, has established that the chain of hydrogen bonds needed for conformational selection can only be completed for d‐glucosamine derivatives. Thus, d‐glucosamine 4‐nitrophenylhydrazone exclusively adopts its cyclic form, but any configurational changes imply the formation of acyclic structures. In conclusion, three criteria dominate structure selection, namely 1) an amino function at the C‐2 position, 2) the “all‐equatorial” substitution mode of the pyranoid ring, and 3) an electron‐withdrawing group on the arylhydrazone are all needed to get the cyclic form only.
Thiazole, Imidazole and Oxazoline Based N,P‐Ligands for Palladium‐Catalyzed Cycloisomerization of 1,6‐Enynes
Authors: Quan Xu , Liu Jianguo , Rabten Wangchuk , Diomedi Simone , Singh Thishana , Andersson Pher G.
Published: June 2016

A series of N,P‐ligands were prepared and evaluated in the asymmetric palladium‐catalyzed cycloisomerization of allyl propargyl ether substrates. The reactivity and enantioselectivity of the reaction was shown to be highly dependent on the chiral skeleton of the ligand structures with ee's ranging from 22–99 %. The proton source had a significant impact on the enantioselectivity. The generation of palladium hydride from formic acid led to the highest ee. A selectivity model based on a proposed transition state was used to predict and explain the enantiomeric outcome of the reaction.
Singlet‐Oxygen‐Initiated Tandem Transformation of 2‐Hexylfuran to the Natural Alkaloids Glochidine and Glochidicine
Authors: Ioannou Georgios I. , Kalaitzakis Dimitris , Vassilikogiannakis Georgios
Published: June 2016

A synthesis of the imidazole alkaloids glochidine and glochidicine is presented. These natural products were prepared by the photooxygenation of a readily accessible alkylfuran precursor using histamine as a nitrogen source. By tailoring the choice of the photosensitizer as well as the conditions used for the cyclization of an N‐acyliminium intermediate, the tandem reaction sequence could be manipulated to afford each of the natural products independently and as desired.
Brønsted‐Acid‐Mediated Divergent Reactions of Betti Bases with Indoles: An Approach to Chromeno[2,3‐b]indoles through Intramolecular Dehydrogenative C2‐Alkoxylation of Indole
Authors: Deb Mohit L. , Pegu Choitanya Dev , Deka Bhaskar , Dutta Prantu , Kotmale Amol S. , Baruah Pranjal K.
Published: June 2016

Divergent reactions of various 1‐(aminoalkyl)naphthols and 2‐(aminoalkyl)phenols (commonly known as Betti bases) with indoles under Brønsted acid catalysis is reported. With the reaction strategies, one can efficiently synthesize important indole derivatives such as 3‐(α,α‐diarylmethyl)indoles and chromeno[2,3‐b]indoles. Furthermore, we disclose here a new C–C bond‐cleavage reaction, in which naphthol and phenol behave as leaving groups to produce diarylmethanes. Inexpensive reagents such as p‐toluenesulfonic acid monohydrate and molecular iodine are used to catalyze the reactions. No metal catalyst is required. The starting material of the reactions, Betti bases, are easily prepared from a three‐component reaction of naphthol/phenol, aldehydes, and secondary amines. The mechanisms for the reactions are established through some control experiments. Quinone methide is the key intermediate for all the reactions reported herein.
Air‐Assisted 2‐Oxo‐Driven Dehydrogenative α,α‐Diamination of 2‐Oxo Aldehydes to 2‐Oxo Acetamidines
Authors: Kumar Atul , Battini Narsaiah , Kumar Raju Ranjith , Athimoolam S. , Ahmed Qazi Naveed
Published: June 2016

An air‐assisted, functional‐group‐driven, mild, additive‐free, three‐component synthetic approach to different 2‐oxo acetamidines from 2‐oxo aldehydes, secondary amines, and anilines was successfully developed. Mechanistically, the transformation proceeds through a highly unstable system (RCOCHN1N2) that rearranges at room temperature and undergoes air‐assisted dehydrogenation to different 2‐oxo acetamidines.
A General CuCl2‐Promoted Alkene Aminochlorination Reaction
Authors: Li Shu‐Qi , Xiong Peng , Zhu Lin , Qian Xiang‐Yang , Xu Hai‐Chao
Published: June 2016

A CuCl2‐promoted alkene aminochlorination reaction has been developed. A variety of anilides that contain a mono‐, di‐, or trisubstituted alkenyl moiety readily participated in this reaction to afford structurally diverse vicinal chloroamines. Studies suggest that the process proceeds by a radical‐type mechanism and that CuCl2 serves as both the oxidant to generate the amidyl radical as well as the chloride source.
Photocatalytic Aminodecarboxylation of Carboxylic Acids
Authors: Lang Simon B. , Cartwright Kaitie C. , Welter Richard S. , Locascio Theresa M. , Tunge Jon A.
Published: June 2016

Aminodecarboxylation of unactivated alkanecarboxylic acids has been accomplished utilizing an organic photocatalyst. This operationally simple reaction utilizes readily available carboxylic acids to chemoselectively generate reactive alkyl intermediates that are not accessible via conventional two‐electron pathways. The organic radical intermediates are efficiently trapped with electrophilic diazo compounds to provide aminated alkanes.
Effects of analgesics on olfactory function and the perception of intranasal trigeminal stimuli
Authors: Mizera L. , Gossrau G. , Hummel T. , Haehner A.
Published: June 2016

Background

There is some evidence suggesting that analgesics have an impact on human chemosensory function, especially opioids and cannabinoids are known to interfere with olfactory function. However, largely unknown is the effect of a long‐term use of analgesics on the intranasal trigeminal system so far. Here, we investigated olfactory function and the perception of intranasal trigeminal stimuli in pain patients with long‐term use of analgesics compared to age‐matched healthy controls.

Methods

For this purpose, a psychophysical approach was chosen to measure these sensory functions in 100 chronic pain patients and 95 controls. Olfactory testing was performed using the ‘Sniffin’ Sticks’ test kit, which involves tests for odour threshold, odour discrimination and odour identification. Further, participants were asked to rate the intensity of trigeminal stimuli by using a visual analogue scale.

Results

We observed that the chronic use of pain medication was associated with significantly reduced perception of intranasal trigeminal stimuli and olfactory function compared to age‐matched controls without intake of analgesics. Results indicate that non‐opioid and opioid drugs, or a combination of both did not differ in their effects on chemosensory function. Further, after eliminating the effect of a co‐existing depression and the use of co‐analgesics, the negative influence of analgesics on olfactory function and trigeminal perception was still evident.

Conclusion

The observed effect might be mediated due to interaction with opioid receptors in trigeminal ganglia and nuclei or due to trigeminal/olfactory interaction. As a practical consequence, patients should be made aware of a possible impairment of their olfactory and trigeminal function under long‐term analgesic treatment.

What does this study add?

We observed that the chronic use of pain medication was associated with significantly reduced olfactory function and perception of intranasal trigeminal stimuli compared to age‐matched controls without intake of analgesics. Non‐opioid and opioid drugs did not differ in their effects on chemosensory function.
Copper Oxide Microstructures with Hemisphere Pineapple Morphology for Selective Amperometric Determination of Vitamin C (L‐ascorbic Acid) in Human Fluids
Authors: Khairy Mohamed , Mahmoud Bahaa G.
Published: June 2016

Control over morphology, surface composition and porosity of nanostructured metal oxides play a significant role in designing a selective and sensitive electrochemical sensor. Herein, we explore a simple synthesis route for control fabrication of porous CuO hemisphere pineapple‐like morphology without using any structure directing agents. The results show that, CuO hemispheres are consisting of self‐assembled porous nanoneedles. The as‐prepared CuO hemispheres were simply drop‐casted onto graphite screen‐printed electrodes (CuO‐SPEs). Then, it was tested for determination of ascorbic acid in Britton Robinson (B. R.) buffer of pH 7.4. Interestingly, the CuO‐SPE provides robust, sensitive, fast response and selective enzyme‐less ascorbic acid sensor. These superior features allowed eﬃcient, costless, stable, and precise non‐enzymatic detection of ascorbic acid in urine samples avoiding interferences and enhancing the accuracy of urinalysis examination.
Paving the way for bioelectrotechnology: Integrating electrochemistry into bioreactors
Authors: Rosa Luis F. M. , Hunger Steffi , Gimkiewicz Carla , Zehnsdorf Andreas , Harnisch Falk
Published: June 2016

The reactor systems used for microbial electrosynthesis, i.e. bioelectrochemical systems for achieving bioproduction so far reported in literature are relatively small in scale and highly diverse in their architecture and modes of operation. The often diverging requirements of the electrochemical and the biological processes and the interdisciplinarity of the field make the engineering of these systems a special challenge. This has led to multiple, differently optimized approaches of reactor vessels, designs and operating conditions making standardization and normalization or even a systematic engineering almost impossible. Overcoming this lack of standardization, scalability and knowledge‐driven engineering is the driving force for this work introducing an upgrade kit for bioreactors transforming these reversibly to bioelectroreactors. The prototypes of the bioreactor upgrade kit were integrated with commercial bioreactor (fermentor) systems and performances compared to a classic, small‐scale bioelectrochemical glass cell system. The use of the upgrade kit allowed interfacing with the existing infrastructure of the conventional bioreactors for growing electroactive microorganisms in pure culture conditions, with the added electrochemical control and further process monitoring. The results of growing Shewanella oneidensis MR‐1 clearly show that these systems can be used to control, monitor, and scale microbial bioelectrochemical processes, providing better resolution of the data for the tested experimental conditions.
Parametric optimization of Cu (II) and Ni (II) adsorption onto coal dust and magnetized sawdust using box‐behnken design of experiments
Authors: Kapur Meghna , Gupta Rishabh , Mondal Monoj Kumar
Published: June 2016

The simultaneous removal of Cu (II) and Ni (II) ions from aqueous solution was investigated by using two different adsorbents (coal dust and magnetized sawdust). Experiments were made as a function of initial metal concentration (5–100 mg/L), adsorbent dose (2–20 g/L), and temperature (20–40°C) for the adsorption of metals by employing response surface methodology (RSM) based on Box–Behnken surface statistical design. The pH was kept constant at 4 and 5 for coal dust and magnetized sawdust, respectively. The magnetized sawdust showed better results for both Cu (II) and Ni (II) removal as compared with coal dust. The F statistics and ANOVA analysis confirmed that the model chosen to explain the relationship between the factors and the response is correct.

For this work, three‐level three‐factorial experimental design has been applied to validate adsorption parameters affecting the combined removal of Cu (II) and Ni (II) onto coal dust and magnetized saw dust. Optimization of process parameters for Cu (II) and Ni (II) ions adsorption onto the adsorbents was done using RSM. The empirical relationship between the response (adsorption percentage of heavy metal) and the independent variables (initial heavy metal concentration, adsorbent dose, and temperature) has been expressed by the quadratic models. These models in turn help to understand and establish the optimized set of conditions without performing the unnecessary experiments at various combinations. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1597–1604, 2016