bluuebunny/crossref_metadata_2025 huggingface dataset:
Hollow Carbon Nanofibers Filled with MnO2 Nanosheets as Efficient Sulfur Hosts for Lithium–Sulfur Batteries
Authors: Li Zhen , Zhang Jintao , Lou Xiong Wen (David)
Published: September 2015

Lithium–sulfur batteries have been investigated as promising electrochemical‐energy storage systems owing to their high theoretical energy density. Sulfur‐based cathodes must not only be highly conductive to enhance the utilization of sulfur, but also effectively confine polysulfides to mitigate their dissolution. A new physical and chemical entrapment strategy is based on a highly efficient sulfur host, namely hollow carbon nanofibers (HCFs) filled with MnO2 nanosheets. Benefiting from both the HCFs and birnessite‐type MnO2 nanosheets, the MnO2@HCF hybrid host not only facilitates electron and ion transfer during the redox reactions, but also efficiently prevents polysulfide dissolution. With a high sulfur content of 71 wt % in the composite and an areal sulfur mass loading of 3.5 mg cm−2 in the electrode, the MnO2@HCF/S electrode delivered a specific capacity of 1161 mAh g−1 (4.1 mAh cm−2) at 0.05 C and maintained a stable cycling performance at 0.5 C over 300 cycles.
Stereodivergent Synthesis of N‐Heterocycles by Catalyst‐Controlled, Activity‐Directed Tandem Annulation of Diazo Compounds with Amino Alkynes
Authors: Liu Kai , Zhu Chenghao , Min Junxiang , Peng Shiyong , Xu Guangyang , Sun Jiangtao
Published: September 2015

A stereodivergent synthesis of five‐membered N‐heterocycles, such as 2,3‐dihydropyrroles, and 2‐methylene and 3‐methylene pyrrolidines, has been developed through a tandem annulation of amino alkynes with diazo compounds and involves the trapping of in situ formed intermediates. Mechanistic investigations indicate that the copper‐catalyzed tandem annulations proceed by allenoate formation and subsequent intramolecular hydroamination. In contrast, the rhodium‐catalyzed protocol features a carbenoid insertion into the NH bond and subsequent Conia‐ene cyclization.
Utilizing Reversible Interactions in Polymeric Nanoparticles To Generate Hollow Metal–Organic Nanoparticles
Authors: Li Longyu , Yuan Conghui , Zhou Dongming , Ribbe Alexander E. , Kittilstved Kevin R. , Thayumanavan S.
Published: September 2015

The use of reversible linkers in polymers has been of interest mainly for biomedical applications. Herein, we present a novel strategy to utilize reversible interactions in polymeric nanoparticles to generate hollow metal–organic nanoparticles (MOPs). These hollow MOPs are synthesized from self‐assembled polymeric nanoparticles using a simple metal–comonomer exchange process in a single step. The control over the size of the polymer precursor particles translates into a straightforward opportunity for controlling MOP sizes. The shell thickness of the MOPs could be easily tuned by the concentration of metal ions in solution. The underlying mechanism for the formation of these hollow MOPs has been proposed. Evidence for the generality of the method is provided by its application to a variety of metal ions with different coordination geometries.
Methane as a Selectivity Booster in the Arc‐Discharge Synthesis of Endohedral Fullerenes: Selective Synthesis of the Single‐Molecule Magnet Dy2TiC@C80 and Its Congener Dy2TiC2@C80
Authors: Junghans Katrin , Schlesier Christin , Kostanyan Aram , Samoylova Nataliya A. , Deng Qingming , Rosenkranz Marco , Schiemenz Sandra , Westerström Rasmus , Greber Thomas , Büchner Bernd , Popov Alexey A.
Published: September 2015

The use of methane as a reactive gas dramatically increases the selectivity of the arc‐discharge synthesis of M‐Ti‐carbide clusterfullerenes (M=Y, Nd, Gd, Dy, Er, Lu). Optimization of the process parameters allows the synthesis of Dy2TiC@C80‐I and its facile isolation in a single chromatographic step. A new type of cluster with an endohedral acetylide unit, M2TiC2@C80, is discovered along with the second isomer of M2TiC@C80. Dy2TiC@C80‐(I,II) and Dy2TiC2@C80‐I are shown to be single‐molecule magnets (SMM), but the presence of the second carbon atom in the cluster Dy2TiC2@C80 leads to substantially poorer SMM properties.
Attraction or Repulsion? London Dispersion Forces Control Azobenzene Switches
Authors: Schweighauser Luca , Strauss Marcel A. , Bellotto Silvia , Wegner Hermann A.
Published: September 2015

Large substituents are commonly seen as entirely repulsive through steric hindrance. Such groups have additional attractive effects arising from weak London dispersion forces between the neutral atoms. Steric interactions are recognized to have a strong influence on isomerization processes, such as in azobenzene‐based molecular switches. Textbooks indicate that steric hindrance destabilizes the Z isomers. Herein, we demonstrate that increasing the bulkiness of electronically equal substituents in the meta‐position decreases the thermal reaction rates from the Z to the E isomers. DFT computations revealed that attractive dispersion forces essentially lower the energy of the Z isomers.
SuFEx on the Surface: A Flexible Platform for Postpolymerization Modification of Polymer Brushes
Authors: Yatvin Jeremy , Brooks Karson , Locklin Jason
Published: September 2015

Polymer brushes present a unique architecture for tailoring surface functionalities due to their distinctive physicochemical properties. However, the polymerization chemistries used to grow brushes place limitations on the monomers that can be grown directly from the surface. Several forms of click chemistry have previously been used to modify polymer brushes by postpolymerization modification with high efficiency, however, it is usually difficult to include the unprotected moieties in the original monomer. We present the use of a new form of click chemistry known as SuFEx (sulfur(VI) fluoride exchange), which allows a silyl ether to be rapidly and quantitatively clicked to a polymer brush grown by free‐radical polymerization containing native ‐SO2F groups with rapid pseudo‐first‐order rates as high as 0.04 s−1. Furthermore, we demonstrate the use of SuFEx to facilely add a variety of other chemical functional groups to brush substrates that have highly useful and orthogonal reactivity, including alkynes, thiols, and dienes.
Fly ash supported Ni―Fe solid acid catalyst for efficient production of diesel additive: intensification through far‐infrared radiation
Authors: Pradhan Piasy , Chakraborty Rajat
Published: September 2015

Novel Ni―Fe solid acid catalyst was prepared through co‐wet impregnation of Fe2 (SO4)3·H2O and Ni (NO3)2·6H2O on fly ash (FA) support. XRD, BET‐BJH, SEM‐EDX, XPS and FTIR methods were employed to characterize the catalyst. The excellent catalyst activity was assessed and optimized in the production of methyl oleate (biodiesel/diesel‐additive). The response surface methodology (RSM) computed optimal parametric values pertaining to maximum oleic acid (OA) conversion (98.37 ± 0.01%) were 15:1 methanol/OA molar ratio, 1:15:2 nickel nitrate: ferric sulphate:FA (wt. ratio) and 4 wt.% (of OA) catalyst concentration in 1 h under conventional heating at mild reaction temperature (60 °C). The optimal catalyst possessed 27.64 m2/g specific surface area and 0.0233 cc/g pore volume with predominantly mesoporous framework. XPS bands confirmed the presence of Fe3+ and mixed Ni2+/Ni3+species rendering an acidity of 5.5 mmol KOH/g. The catalyst comprised of crystalline Fe2O3, Ni2O3 and NiS phases as revealed from XRD analysis. This study also reports the remarkable intensification of esterification reaction through an energy‐efficient application of far‐infrared radiation protocol (1/3rd of conventional power requirement) resulting 99.20% OA conversion in only 10 min at the derived optimal conditions. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Core–shell particles of poly(methyl methacrylate)‐block‐poly(n‐butyl acrylate) synthesized via reversible addition–fragmentation chain‐transfer emulsion polymerization and the polymer's application in toughening polycarbonate
Authors: Zhu Yue , Gao Xiang , Luo Yingwu
Published: September 2015

Poly(methyl methacrylate) (PMMA) block copolymer is interesting because it is compatible with many polymers. A series of poly(methyl methacrylate)‐b‐poly(n‐butyl acrylate) (PMMA‐b‐PnBA) diblock copolymers with various compositions was synthesized via reversible addition–fragmentation chain‐transfer (RAFT) emulsion polymerization with the amphiphilic oligo(methacrylic acid41‐b‐methyl methacrylate8) RAFT agent as both the polymerization mediator and surfactant. The molecular weights of the block copolymers agreed well with the theoretical prediction, although the polydispersity indices were relatively broad. The resulting core [poly(n‐butyl acrylate)]–shell (PMMA) particles of PMMA‐b‐PnBA were found to be very effective impact modifiers for polycarbonate (PC). The diblock copolymer was well dispersed in 100–300‐nm particles in the PC matrix, and the dispersed particle size was highly dependent on the block copolymer compositions. PMMA250‐b‐PnBA550 (the subscripted number signifies the designed degree of polymerization), which was dispersed into 100‐nm particles, presented the best capability for improving the impacting properties. Compared with the neat PC, the notched impact strength of PC toughened by 5 wt % PMMA250‐b‐PnBA550 was increased by four times to 62.81 kJ/m2 with the same yield strength, a slightly decreased modulus, an increased elongation at break, and an increased tensile strength. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 132, 42833.
Light‐scattering capacity of ethylene–vinyl acetate copolymers in polypropylene: Toward high haze and transmittance
Authors: Luo Shanshan , Yi Ping , Xiong Ying , Shen Jiabin , Guo Shaoyun
Published: September 2015

Light‐scattering materials were fabricated by the melt blending of polypropylene with an ethylene–vinyl acetate copolymer (EVA) to prevent the glare effect of light‐emitting diodes. The results show that the light‐scattering capacity was remarkably dependent on the phase morphologies of EVA. (1) When EVA was dispersed as spherical droplets, the transmittance and haze gradually increased with the enrichment of EVA, and the half‐peak width of the light‐scattering pattern reached a maximum when 30 wt % EVA was loaded. On the basis of the analysis of Mie scattering theory, the enlargement of scattering particles promoted light transmittance, and more incoming light was deflected at the arclike interfaces. This induced a distinct antiglare effect. (2) When scattering particles deformed and expanded vertically in the light‐transmitting direction, the light‐scattering capacity turned out to be weakened by further enrichment of the EVA phase. The planelike interfaces reduced the deflection of incoming light, and this led to decreases in the scattering angles. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42844.
Determination of the fracture energy in polymeric films by in situ photoelasticimetry on double edge notch specimen
Authors: Dubelley Florence , Planes Emilie , Bas Corine , Yrieix Bernard , Flandin Lionel
Published: September 2015

The fracture toughness is key parameters to select polymeric films. The essential work of fracture (EWF) is a phenomenological but efficient way to characterize this resistance to fracture. One can gain valuable information on the resistance to perforation and propagation of flaws. A new technique was developed to better understanding the EWF experiments. A tensile test combined to photoelasticimetry allows following in situ the geometry and amount of plastic deformation on double edge notched specimen. The EWF parameters are determined when the plastic deformation appears constant, so when the fracture energy Wf only contributes to rupture filament. This new methodology requires just a single sample, whereas at least five specimens are required for general method. It will help characterize expensive polymeric films or reveal the heterogeneous behavior, for instance after polymer ageing. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 132, 42854.
Efficient removal of Cu(II) using amino‐functionalized superparamagnetic nanoparticles prepared via SI‐ATRP
Authors: Yuan Caideng , Cui Mingtong , Feng Longlong , Wang Jingpeng , Peng Yan
Published: September 2015

An amino‐functionalized nano‐adsorbent (DETA‐MNPs) was prepared by a process involving: (1) synthesis of superparamagnetic Fe3O4 nanoparticles; (2) introduction of amino groups after which ATRP initiator was anchored; (3) grafting of glycidyl methacrylate (GMA) via SI‐ATRP; and (4) ring‐opening reaction of epoxy groups with diethylenetriamine (DETA). The nano‐adsorbent was characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), transmission electron microscope (TEM), and vibrating sample magnetometer (VSM) and applied to remove Cu(II) in batch experiments. The effects of pH, Cu(II) concentrations, solution ionic strength, and contact time were investigated. The results show that the DETA‐MNPs are spherical with cubic spine structure, high saturation magnetization (41.9 emu g−1), and an average diameter of 10 nm. The maximum Cu(II) adsorption capacity achieves 83.33 mg g−1 at pH 5.0 by Langmuir model. The adsorption process is highly pH‐dependent and reaches equilibrium within 20 min. Furthermore, the DETA‐MNPs exhibit excellent dispersibility and reusability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 132, 42859.
Effect of composition on morphology structure and cell affinity of poly(caprolactone‐co‐glycolide)‐co‐poly(ethylene glycol) microspheres
Authors: Li Zhe , Shen Hong , Shuai Kegang , Hu Xixue
Published: September 2015

Poly(caprolactone‐co‐glycolide)‐co‐poly(ethylene gylcol) copolymers (PCEG) with various composition were synthesized by copolymerization of GA, CL, and PEG. PCEG microspheres were fabricated by oil‐in‐water (o/w) emulsion and solvent‐evaporation technique. Effect of chemical composition on hydrophilicity, crystallinity, and degradation of the PCEG was investigated. It was demonstrated that morphology structure of the microspheres was greatly influenced by chemical composition and hydrophilicity of the PCEG polymer. PCEG microspheres could change from a smooth structure to a regular porous structure and an irregular structure. Moreover, the pore size of them increased with increment of PEG content and length. Cell attachment and growth on the PCEG microspheres were evaluated by using mouse NIH 3T3 fibroblasts as model cells in vitro. The result showed that the PCEG microspheres with large porous structure were more favorable for cell attachment and growth. Thus the PCEG microspheres with rapid degradation rate and large porous structure possess potential use as injectable scaffolds in tissue engineering. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 132, 42861.
PET interleaving veils for improved fracture toughness of glass fibre/low‐styrene‐emission unsaturated polyester resin composites
Authors: Fitzmaurice Kevin , Ray Dipa , Mccarthy Michael A.
Published: September 2015

The use of interleaved polyethylene terephthalate (PET) veils to increase the interlaminar fracture toughness of glass fiber‐reinforced, low‐styrene emission, unsaturated polyester resin composites, was investigated. PET, being chemically similar to the unsaturated polyester resin, was expected to exhibit good wetting and strong interaction with the matrix. Composite laminates were manufactured by hand lay‐up, with the veil content varying up to 7%. The effects of PET veils on the interlaminar shear strength, flexural strength, flexural modulus, glass transition temperature, damping parameters, and Mode‐I interlaminar fracture toughness of the composite were studied. The veils were found to enhance most of these properties, with only minor negative effects on flexural stiffness and Tg. The PET/resin bonding did indeed prove to be strong, but the enhancement of fracture toughness was not as much as expected, because of the weaker glass/resin interface providing an alternative crack propagation path. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42877.
Fabricating and Tailoring Polyaniline (PANI) Nanofibers with High Aspect Ratio in a Low‐Acid Environment in a Magnetic Field
Authors: Ma Yong , Chen Yanhui , Mei Ang , Qiao Mingtao , Hou Chunping , Zhang Hepeng , Zhang Qiuyu
Published: September 2015

In a 0.010 m HCl solution, we successfully transformed irregular polyaniline (PANI) agglomerates into uniform PANI nanofibers with a diameter of 46–145 nm and a characteristic length on the order of several microns by the addition of superparamagnetic Fe3O4 microspheres in a magnetic field. The PANI morphological evolution showed that the PANI nanofibers stemmed from the PANI coating shell synthesized on the surface of the Fe3O4 microsphere chains. It was found that the magnetic field could optimize the PANI nanofibers with a narrow diameter size distribution, and effectively suppressed secondary growth. When compared with other microspheres (like silica and polystyrene), only the use of superparamagnetic Fe3O4 microspheres resulted in the appearance of PANI nanofibers. Attempts to form these high‐quality PANI nanofibers in other concentrations of HCl solution were unsuccessful. This deficiency was largely attributed to the inappropriate quantity of aniline cations.
Murine Cyp3a knockout chimeric mice with humanized liver: prediction of the metabolic profile of nefazodone in humans
Authors: Nakada Naoyuki , Kawamura Akio , Kamimura Hidetaka , Sato Koya , Kazuki Yasuhiro , Kakuni Masakazu , Ohbuchi Masato , Kato Kota , Tateno Chise , Oshimura Mitsuo , Usui Takashi
Published: September 2015

Chimeric mice with humanized livers (PXB mice) are used to investigate the metabolism and pharmacokinetics of drugs in humans. However, residual murine enzymatic activities derived from the liver and the presence of mouse small intestinal metabolism can hamper the prediction of human drug metabolism. Recently murine Cytochrome P450 3a gene knockout chimeric mice with humanized livers (Cyp3a KO CM) were developed. To evaluate the prediction of drug metabolism, nefazodone (NEF) was administered orally at 10 mg/kg to the following mouse strains: Cyp3a KO CM, murine Cyp3a gene knockout (Cyp3a KO), PXB and severe combined immunodeficiency (SCID) mice. Liquid chromatography‐mass spectrometry was used for metabolic profiling of plasma, urine and bile. The prediction of human metabolite levels such as hydroxy nefazodone (OH‐NEF), triazoledione form (TD), m‐chlorophenylpiperazine and dealkyl metabolites in Cyp3a KO CM was superior to that in Cyp3a KO, PXB or SCID mice. Further, clinical exposure levels of NEF, OH‐NEF and TD were reproduced in Cyp3a KO CM. In contrast, NEF was rapidly metabolized to TD in both PXB and SCID mice but not in Cyp3a KO mice, suggesting that murine CYP3A is involved in the elimination of NEF in these mice. These findings demonstrate that the metabolic profile of NEF in Cyp3a KO CM differs qualitatively and quantitatively from that in PXB mice due to the higher metabolic rate of NEF and its metabolites via murine CYP3A. Therefore Cyp3a KO CM might be useful in predicting the metabolic profiles of drug candidates in humans. Copyright © 2016 John Wiley & Sons, Ltd.
Inferring Others' Hidden Thoughts: Smart Guesses in a Low Diagnostic World
Authors: Street Chris N. H. , Bischof Walter F. , Vadillo Miguel A. , Kingstone Alan
Published: September 2015

People are biased toward believing that what others say is what they truly think. This effect, known as the truth bias, has often been characterized as a judgmental error that impedes accuracy. We consider an alternative view: that it reflects the use of contextual information to make the best guess when the currently available information has low diagnosticity. Participants learnt the diagnostic value of four cues, which were present during truthful statements between 20% and 80% of the time. Afterwards, participants were given contextual information: either that most people would lie or that most would tell the truth. We found that people were biased in the direction of the context information when the individuating behavioral cues were nondiagnostic. As the individuating cues became more diagnostic, context had less to no effect. We conclude that more general context information is used to make an informed judgment when other individuating cues are absent. That is, the truth bias reflects a smart guess in a low diagnostic world. Copyright © 2015 John Wiley & Sons, Ltd.
Meta-analysis of the association between preoperative anaemia and mortality after surgery
Authors: Fowler A J , Ahmad T , Phull M K , Allard S , Gillies M A , Pearse R M
Published: September 2015

Background

Numerous published studies have explored associations between anaemia and adverse outcomes after surgery. However, there are no evidence syntheses describing the impact of preoperative anaemia on postoperative outcomes.

Methods

A systematic review and meta-analysis of observational studies exploring associations between preoperative anaemia and postoperative outcomes was performed. Studies investigating trauma, burns, transplant, paediatric and obstetric populations were excluded. The primary outcome was 30-day or in-hospital mortality. Secondary outcomes were acute kidney injury, stroke and myocardial infarction. Predefined analyses were performed for the cardiac and non-cardiac surgery subgroups. A post hoc analysis was undertaken to evaluate the relationship between anaemia and infection. Data are presented as odds ratios (ORs) with 95 per cent c.i.

Results

From 8973 records, 24 eligible studies including 949 445 patients were identified. Some 371 594 patients (39·1 per cent) were anaemic. Anaemia was associated with increased mortality (OR 2·90, 2·30 to 3·68; I2 = 97 per cent; P < 0·001), acute kidney injury (OR 3·75, 2·95 to 4·76; I2 = 60 per cent; P < 0·001) and infection (OR 1·93, 1·17 to 3·18; I2 = 99 per cent; P = 0·01). Among cardiac surgical patients, anaemia was associated with stroke (OR 1·28, 1·06 to 1·55; I2 = 0 per cent; P = 0·009) but not myocardial infarction (OR 1·11, 0·68 to 1·82; I2 = 13 per cent; P = 0·67). Anaemia was associated with an increased incidence of red cell transfusion (OR 5·04, 4·12 to 6·17; I2 = 96 per cent; P < 0·001). Similar findings were observed in the cardiac and non-cardiac subgroups.

Conclusion

Preoperative anaemia is associated with poor outcomes after surgery, although heterogeneity between studies was significant. It remains unclear whether anaemia is an independent risk factor for poor outcome or simply a marker of underlying chronic disease. However, red cell transfusion is much more frequent amongst anaemic patients.
One Way to Govern: The Complementary Model of Board Governance
Authors: Abbott Tom
Published: September 2015

This is the second in an occasional Board Leadership series in which leading proponents of different models and approaches to governance are invited to answer a series of standard questions. The first article in the series, which appeared in Issue 134, was on sociocracy, written by John Buck. This piece about the Complementary Model of Board Governance comes from Tom Abbott, who is the director of AMC NPO Solutions and an Associate Certified Coach as designated by the International Coach Federation.
QbD‐oriented development and validation of a bioanalytical method for nevirapine with enhanced liquid–liquid extraction and chromatographic separation
Authors: Beg Sarwar , Chaudhary Vandna , Sharma Gajanand , Garg Babita , Panda Sagar Suman , Singh Bhupinder
Published: September 2015

The present studies describe the systematic quality by design (QbD)‐oriented development and validation of a simple, rapid, sensitive and cost‐effective reversed‐phase HPLC bioanalytical method for nevirapine in rat plasma. Chromatographic separation was carried out on a C18 column using isocratic 68:9:23% v/v elution of methanol, acetonitrile and water (pH 3, adjusted by orthophosphoric acid) at a flow rate of 1.0 mL/min using UV detection at 230 nm. A Box–Behnken design was applied for chromatographic method optimization taking mobile phase ratio, pH and flow rate as the critical method parameters (CMPs) from screening studies. Peak area, retention time, theoretical plates and peak tailing were measured as the critical analytical attributes (CAAs). Further, the bioanalytical liquid–liquid extraction process was optimized using an optimal design by selecting extraction time, centrifugation speed and temperature as the CMPs for percentage recovery of nevirapine as the CAA. The search for an optimum chromatographic solution was conducted through numerical desirability function. Validation studies performed as per the US Food and Drug Administration requirements revealed results within the acceptance limit. In a nutshell, the studies successfully demonstrate the utility of analytical QbD approach for the rational development of a bioanalytical method with enhanced chromatographic separation and recovery of nevirapine in rat plasma. Copyright © 2015 John Wiley & Sons, Ltd.
Understand your key legal responsibilities for pregnant, parenting student‐athletes
Authors: O'Brien Timothy
Published: September 2015

We've heard the success stories about schools, coaches and team members supporting pregnant and parenting student‐athletes. But we've also heard numerous reports of indifference, ignorance, and even lawsuits involving the mistreatment of pregnant and parenting student‐athletes.
Activation of Toll like receptor 3 induces spermatogonial stem cell apoptosis
Authors: Hu Jianxin , Song Dalong , Luo Guangheng , Xu Suxiong , Cao Ying , Sun Zhaolin
Published: September 2015

Germ cell apoptosis may be associated with the male infertility. The pathogenesis is to be further understood. Viral infection is one of the causative factors of apoptosis of the body cells. This study aims to investigate the role of activation of Toll like receptor (TLR)3 in the induction of germ cell apoptosis. In this study, spermatogonial stem cells (SSC) were isolated from C57BL/6 mouse testes. The expression of TLR3 on SSC was by RT‐qPCR and Western blotting. polyinosinic–polycytidylic acid (Poly I:C) was employed to activate TLR3 on SSCs. The results showed that re‐activation by PolyI:C induced SSC apoptosis. Exposure to PolyI:C induced interferon regulatory factor 3 (IRF3) phosphorylation in SSCs. TLR3 and IRF3 formed a complex in the SSCs. The complex of TLR3/IRF3 bound to the promoter of Fas ligand and promoted Fas ligand expression in SSC, and thus induced SSC apoptosis. In conclusion, the results of the present study indicate that activation of TLR3 by PolyI:C induces the SSC apoptosis, which implies that viral infection may interfere with the male germ cell development. Copyright © 2015 John Wiley & Sons, Ltd.
Discovery of New Classes of Compounds that Reactivate Acetylcholinesterase Inhibited by Organophosphates
Authors: Katz Francine S. , Pecic Stevan , Tran Timothy H. , Trakht Ilya , Schneider Laura , Zhu Zhengxiang , Ton‐That Long , Luzac Michal , Zlatanic Viktor , Damera Shivani , Macdonald Joanne , Landry Donald W. , Tong Liang , Stojanovic Milan N.
Published: September 2015

Acetylcholinesterase (AChE) that has been covalently inhibited by organophosphate compounds (OPCs), such as nerve agents and pesticides, has traditionally been reactivated by using nucleophilic oximes. There is, however, a clearly recognized need for new classes of compounds with the ability to reactivate inhibited AChE with improved in vivo efficacy. Here we describe our discovery of new functional groups—Mannich phenols and general bases—that are capable of reactivating OPC‐inhibited AChE more efficiently than standard oximes and we describe the cooperative mechanism by which these functionalities are delivered to the active site. These discoveries, supported by preliminary in vivo results and crystallographic data, significantly broaden the available approaches for reactivation of AChE.
Combined Experimental and Computational Studies of a Na2Ni1−xCuxFe(CN)6 Cathode with Tunable Potential for Aqueous Rechargeable Sodium‐Ion Batteries
Authors: Hung Tai‐Feng , Chou Hung‐Lung , Yeh Yu‐Wen , Chang Wen‐Sheng , Yang Chang‐Chung
Published: September 2015

Herein, potential‐tunable Na2Ni1−xCuxFe(CN)6 nanoparticles with three‐dimensional frameworks and large interstitial spaces were synthesized as alternative cathode materials for aqueous sodium‐ion batteries by controlling the molar ratio of NiII to CuII at ambient temperature. The influence of the value of x on the crystalline structure, lattice parameters, electrochemical properties, and charge transfer of the resultant compound was explored by using powder X‐ray diffractometry, density functional theory, cyclic voltammetry, galvanostatic charge–discharge techniques, and Bader charge analysis. Of the various formulations investigated, that with x=0.25 delivered the highest reversible capacity, superior rate capability, and outstanding cycling performance. These attributes are ascribed to its unique face‐centered cubic structure for facile sodium‐ion insertion/extraction and the strong interactions between Cu and N atoms, which promote structural stability.
β‐Amyrin Biosynthesis: The Methyl‐30 Group of (3S)‐2,3‐Oxidosqualene Is More Critical to Its Correct Folding To Generate the Pentacyclic Scaffold than the Methyl‐24 Group
Authors: Hoshino Tsutomu , Miyahara Yuri , Hanaoka Masaki , Takahashi Kazunari , Kaneko Ikki
Published: September 2015

Oxidosqualene cyclases catalyze the transformation of oxidosqualene (1) into numerous cyclic triterpenes. Enzymatic reactions of 24‐noroxidosqualene (8) and 30‐noroxidosqualene (9) with Euphorbia tirucalli β‐amyrin synthase were conducted to examine the role of the branched methyl groups of compound 1 in the β‐amyrin biosynthesis. Substrate 8 almost exclusively afforded 30‐nor‐β‐amyrin (>95.5 %), which was produced through a normal cyclization pathway, along with minor products (<4.5 %). However, a lack of the Me‐30 group (analogue 9) resulted in significantly high production of premature cyclization products, including 6/6/6/5‐fused tetracyclic and 6/6/6/6/5‐fused pentacyclic skeletons (64.6 %). In addition, the fully cyclized product (35.4 %) having the 6/6/6/6/6‐fused pentacycle was produced; however, the normally cyclized product, 29‐nor‐β‐amyrin was present in only 18.6 % of these products. The conversion yield of substrate 8 possessing a Z‐Me group at the terminus was approximately twofold greater than that of compound 9 with an E‐Me group. Thus, the Me‐30 group is essential for the correct folding of a chair–chair–chair–boat–boat conformation of compound 1 for the production of the β‐amyrin scaffold, whereas the Me‐24 group exerts little influence on the normal polycyclization cascade. Here, we show that the Me‐30 group plays critical roles in constructing the ordered architecture of a chair–chair–chair–boat–boat structure, in facilitating the ring‐expansion reactions, and in performing the final deprotonation reaction at the correct position.
Development of Potent Adenosine Monophosphate Activated Protein Kinase (AMPK) Activators
Authors: Dokla Eman M. E. , Fang Chun‐Sheng , Lai Po‐Ting , Kulp Samuel K. , Serya Rabah A. T. , Ismail Nasser S. M. , Abouzid Khaled A. M. , Chen Ching‐Shih
Published: September 2015

Previously, we reported the identification of a thiazolidinedione‐based adenosine monophosphate activated protein kinase (AMPK) activator, compound 1 (N‐[4‐({3‐[(1‐methylcyclohexyl)methyl]‐2,4‐dioxothiazolidin‐5‐ylidene}methyl)phenyl]‐4‐nitro‐3‐(trifluoromethyl)benzenesulfonamide), which provided a proof of concept to delineate the intricate role of AMPK in regulating oncogenic signaling pathways associated with cell proliferation and epithelial–mesenchymal transition (EMT) in cancer cells. In this study, we used 1 as a scaffold to conduct lead optimization, which generated a series of derivatives. Analysis of the antiproliferative and AMPK‐activating activities of individual derivatives revealed a distinct structure–activity relationship and identified 59 (N‐(3‐nitrophenyl)‐N′‐{4‐[(3‐{[3,5‐bis(trifluoromethyl)phenyl]methyl}‐2,4‐dioxothiazolidin‐5‐ylidene)methyl]phenyl}urea) as the optimal agent. Relative to 1, compound 59 exhibits multifold higher potency in upregulating AMPK phosphorylation in various cell lines irrespective of their liver kinase B1 (LKB1) functional status, accompanied by parallel changes in the phosphorylation/expression levels of p70S6K, Akt, Foxo3a, and EMT‐associated markers. Consistent with its predicted activity against tumors with activated Akt status, orally administered 59 was efficacious in suppressing the growth of phosphatase and tensin homologue (PTEN)‐null PC‐3 xenograft tumors in nude mice. Together, these findings suggest that 59 has clinical value in therapeutic strategies for PTEN‐negative cancer and warrants continued investigation in this regard.
Noncovalent Molecular Doping of Two‐Dimensional Materials
Authors: Cai Bo , Zhang Shengli , Yan Zhong , Zeng Haibo
Published: September 2015

Two‐dimensional materials have become one of the hottest topics in physics, chemistry, and materials science during the past decade owing to their outstanding physical and chemical properties. To further expand their potential applications, more research efforts are needed to improve their performance and overcome their weaknesses. This review focus on the mechanisms, effects, influencing factors, and characterization of noncovalent molecular doping of two‐dimensional materials.
Theoretical Explanation for How SO3H‐Functionalized Ionic Liquids Promote the Conversion of Cellulose to Glucose
Authors: Li Jingjing , Li Jinghua , Zhang Dongju , Liu Chengbu
Published: September 2015

While the catalytic transformation of cellulose to glucose by functionalized ionic liquids (ILs) has been achieved successfully under mild conditions, insight into the fundamental molecular mechanism is still lacking. The present work presents the first attempt to address the fundamental reaction chemistry of the catalytic transformation. An enzyme‐like catalytic mechanism of ILs, in which glycosidic bond hydrolysis proceeds through a retaining mechanism and/or an inverting mechanism, is proposed. DFT calculations show that both mechanisms involve moderate barriers (<30 kcal mol−1), which is consistent with the catalytic performance of the ILs under mild conditions (<100 °C). The “biomimetic” mechanism model proposed herein is expected to be viable for understanding the unique catalytic activity of ILs under mild conditions.
One‐Pot 2‐Methyltetrahydrofuran Production from Levulinic Acid in Green Solvents Using Ni‐Cu/Al2O3 Catalysts
Authors: Obregón Iker , Gandarias Iñaki , Miletić Nemanja , Ocio Ainhoa , Arias Pedro L.
Published: September 2015

The one‐pot hydrogenation of levulinic acid to 2‐methyltetrahydrofuran (MTHF) was performed using a series of Ni‐Cu/Al2O3 catalysts in green solvents, such as water and biomass‐derived alcohols. Ni/Al2O3 provided the highest activity, whereas Cu/Al2O3 was the most selective, reaching a 75 % MTHF yield at 250 °C after 24 h reaction time. Synergetic effects were observed when bimetallic Ni‐Cu/Al2O3 catalysts were used, reaching a 56 % MTHF yield in 5 h at 250 °C for the optimum Ni/Cu ratio. Remarkably, these high yields were obtained using non‐noble metal‐based catalysts and 2‐propanol as the solvent. The catalytic activity and selectivity results are correlated to temperature programmed reduction (TPR), XRD, and STEM characterization data, identifying the role associated with mixed Ni–Cu particles in addition to monometallic Cu and Ni.
Improved detection of diffuse large B‐cell lymphoma by flow cytometric immunophenotyping—Effect of tissue disaggregation method
Authors: Vallangeon Bethany D. , Tyer Christy , Williams Beverly , Lagoo Anand S.
Published: September 2015

Background

Flow cytometric immunophenotyping (FCI) is recognized as a rapid, sensitive, and accurate method for diagnosis of B‐cell lymphomas. We observed that FCI failed to identify the clonal B‐cell population in several cases of large B‐cell lymphoma (DLBCL) when tissue samples were prepared by a commercially available mechanical tissue disaggregation method. We tested a manual tissue disaggregation method and compared it with the mechanical method.

Methods

FCI findings from 51 cases of DLBCL processed with the mechanical tissue disaggregation method, 27 cases processed using the manual method, and 15 cases processed using a combination of both methods were compared. The histological and immunohistochemical findings in each case were reviewed.

Results

FCI detected a clonal B‐cell population in 88.9% of cases processed by the manual tissue disaggregation method, 66.7% of cases processed by a combination of the manual and mechanical disaggregation methods, and in 62.7% of cases processed solely by the mechanical tissue disaggregation method (P < 0.01 Fisher exact). Manual processing yielded positive FCI results in 81.8% of the nodal tissue samples and 93.8% of the extra‐nodal tissue samples, whereas mechanical disaggregation was particularly inefficient in preserving large lymphoma cells from extra‐nodal tissue: 71.4% of the nodal and 56.8% of the extra‐nodal tissue samples processed by the mechanical method showed clonal B‐cells by flow cytometry (P < 0.006, Fisher exact).

Conclusions

The diagnostic yield of FCI in DLBCL can be significantly improved by utilizing a manual disaggregation method, particularly in extra‐nodal tissue samples. © 2015 International Clinical Cytometry Society
Fosinopril Prevents the Development of Tactile Allodynia in a Streptozotocin‐Induced Diabetic Rat Model
Authors: Araiza‐Saldaña Claudia Ivonne , Pedraza‐Priego Erick Fabián , Torres‐López Jorge Elías , Rocha‐González Héctor Isaac , Castañeda‐Corral Gabriela , Hong‐Chong Enrique , Granados‐Soto Vinicio
Published: September 2015

Preclinical Research

The aim of this study was to evaluate fosinopril‐induced changes in hemodynamic parameters and tactile allodynia in a rat model of diabetes. Diabetes was induced by streptozotocin (STZ; 50 mg/kg, i.p.) in male Wistar rats. STZ produced hyperglycemia, weight loss, polydipsia, polyphagia, and polyuria as well as long‐term arterial hypotension, bradycardia, and tactile allodynia at 10–12 weeks. Daily administration of the angiotensin converting enzyme inhibitor, fosinopril (25 mg/kg, p.o., for 11 weeks) partially reduced the loss of body weight, decreased hyperglycemia, and systolic blood pressure in diabetic rats. Likewise, systemic administration of fosinopril prevented the development and maintenance of tactile allodynia in STZ‐induced diabetic rats. These data suggest that fosinopril may have a role in the pharmacotherapy of diabetic neuropathic pain. Drug Dev Res 76 : 442–449, 2015. © 2015 Wiley Periodicals, Inc.
Extracellular RNA facilitates hypoxia‐induced leukocyte adhesion and infiltration in the lung through TLR3‐IFN‐γ‐STAT1 signaling pathway
Authors: Biswas Indranil , Singh Bandana , Sharma Manish , Agrawala Paban K. , Khan Gausal A.
Published: September 2015

Endogenous ligands released from dying cells, including extracellular RNA (eRNA), cause TLR activation, which is associated with inflammation and vascular diseases. However, the importance of this response in acute hypoxia (AH) remains unexplored. Here, we observed eRNA‐mediated TLR3 activation during exposure of mice to AH in the absence of exogenous viral stimuli. RNaseA treatment diminished AH‐induced expression of IFN and cell adhesion molecules (CAMs) and myeloid cell infiltration in the lung, and TLR3 gene silencing or neutralization with antibodies markedly attenuated AH‐ or poly I:C‐induced IFN and CAM expression and leukocyte adhesion (LA) and myeloid cell infiltration in the lung. However, RNaseA treatment or TLR3 gene silencing failed to alter AH‐induced cell death and proliferation in lung vasculature. Furthermore, IFN‐γ—but not IFN‐α—regulated AH‐induced CAM expression and LA. Treatment with RNaseA, TLR3 siRNA, neutralizing antibodies, or a STAT1 inhibitor substantially decreased AH‐ and poly I:C‐induced STAT1 phosphorylation, CAM expression, and myeloid cell infiltration, suggesting a central role for STAT1 phosphorylation in AH‐induced LA and infiltration. We conclude that eRNA activates TLR3 and facilitates, through in vivo IFN‐γ˗STAT1 signaling, AH‐induced leukocyte infiltration in the lung. Thus, RNaseA might provide a therapeutic alternative for patients with lung diseases.
A Family of IrIII Complexes with High Nonlinear Optical Response and Their Potential Use in Light‐Emitting Devices
Authors: González Iván , Cortés‐Arriagada Diego , Dreyse Paulina , Sanhueza‐Vega Luis , Ledoux‐Rak Isabelle , Andrade Daniel , Brito Iván , Toro‐Labbé Alejandro , Soto‐Arriaza Marco , Caramori Stefano , Loeb Bárbara
Published: September 2015

We synthesized a new family of IrIII complexes [Ir(R1‐ppy)2(R2‐ppl)](PF6), where R1‐ppy = 2‐phenylpyridine (ppy) or 2,4‐difluorophenylpyridine (F2‐ppy) and R2‐ppl = pyrazino[2,3‐f][1,10]phenanthroline (ppl) or 2,3‐diethoxycarbonylpyrazino [2,3‐f][1,10]phenanthroline (deeppl). The complexes were experimentally and theoretically characterized, noting the importance of the R1 substituent on the modulation of HOMO level and its impact on the electronic properties. These compounds exhibit high second‐order nonlinear optics (NLO) activity, especially, those with F2‐ppy ligands; this substituent modulates the charge transfer, optimizing the NLO response. The compounds also show blueshifted emissions, both in solution and as a solid film, which is desirable for use in light‐emitting devices. This is the first use of the synthesized complexes for application in the two tasks.
Pyrazole‐Stabilized Dinuclear Palladium(II) Chalcogenolates Formed by Oxidative Addition of Bis[2‐(4‐bromopyrazol‐1‐yl)ethyl] Dichalcogenides to Palladium(II) – Tailoring of Pd–S/Se Nanoparticles
Authors: Nayan Sharma Kamal , Joshi Hemant , Prakash Om , Sharma Alpesh K. , Bhaskar Renu , Singh Ajai K.
Published: September 2015

Bis[2‐(4‐bromopyrazol‐1‐yl)ethyl] disulfide and diselenideL1andL2were synthesized by the reactions of 4‐bromo‐1‐(2‐chloroethyl)‐1H‐pyrazole with the in situ generated Na2S2and Na2Se2. The reactions ofL1andL2with 2 equiv. of [PdCl2(CH3CN)2] in CH3CN at 70 °C proceed through an oxidative addition/reductive elimination sequence to the PdIIcenter to form the chalcogenolato‐bridged dinuclear palladium(II) complexes [Pd2Cl2(μ‐EN)2] [1(E = S) and2(E = Se); EN = 2‐(4‐bromopyrazol‐1‐yl)ethanechalcogenolate]. The reactions of1and2with CH3CN and AgBF4resulted in the formation of [Pd2(CH3CN)2(μ‐EN)2]·2BF4(3and4). CompoundsL1,L2, and their complexes1–4have been characterized through1H,13C{1H}, and77Se{1H} nuclear magnetic resonance (NMR) spectroscopy; infrared (IR) spectroscopy; and high‐resolution mass spectrometry (HRMS). The single‐crystal X‐ray structures of2–4have revealed distorted square‐planar geometries around the Pd center in each case. The Pd–S and Pd–Se bond lengths are in the ranges 2.277(2)–2.296(2) and 2.372(9)–2.3971(17) Å, respectively. Single‐source precursor routes for the synthesis of palladium chalcogenide nanoparticles (NPs) have been developed by the thermolyses of1–4in 1:1 mixtures of oleic acid (OA) and 1‐octadecene (ODE). Pd17Se15NPs were formed from both PdIIselenolates2and4, whereas Pd4S NPs and a mixture of Pd16S7(ca. 68 %) and PdS (ca. 32 %) NPs were obtained from PdIIthiolates1and3, respectively. Transmission electron microscopy (TEM), scanning electron microscopy with energy‐dispersive X‐ray spectroscopy (SEM‐EDX), and powder X‐ray diffraction (PXRD) have been used to authenticate the NPs. X‐ray photoelectron spectroscopy (XPS) studies on the NPs have revealed that there is a charge transfer from Pd to S/Se. The compositions of the NPs determined from XPS are consistent with the PXRD results.
Bioinspired Nanoparticle‐Assembly Route to a Hybrid Scaffold: Designing a Robust Heterogeneous Catalyst for Asymmetric Dihydroxylation of Olefins
Authors: Shilpa Nagaraju , Manna Joydeb , Rana Rohit Kumar
Published: September 2015

A hierarchical polyamine‐silica structure is shown to encase osmate ions resulting in robust and reusable catalysts for asymmetric dihydroxylation of olefins with a high TON (>700). Whilst the polypeptide and related polyamines resembling a proteinaceous matrix in biosilica nanostructures preserve the osmate as the active centre, the surrounding assembly of silica nanoparticles imparts stability and textural properties to the catalyst. This confinement of osmate in the microsphere leads to higher catalytic activity and enantioselectivity for a variety of olefins as the substrate. The hybrid nature of the catalyst not only allows for the usage of various solvent systems, but also provides a means to be integrated with multi‐components/functions for tuning the activity, catalysis separation and reusability. Interestingly, the presence of polyamine makes the catalyst retain its activity even in the presence of chelating acids like citrate that are known to diminish enantioselectivity.
In Silico Study on Chemical Properties and Reactivity of Enal Derivatives
Authors: Borosky Gabriela L. , Laali Kenneth K.
Published: September 2015

The chemical properties and reactivity of enals were explored by means of quantum chemical methods of calculation. The substituent effects were examined by analyzing the formation of oxonium and carbenium intermediates via protonation reactions as models for activation of enals. Considering the nucleophilic addition of organometallic reagents to enals as an important synthetic step, formation and reactivity of the anionic derived species were modeled computationally for the bis‐silylated enals and their subsequent reaction with model electrophiles, in order to gain insight into the regio‐ and stereoselectivity previously observed in electrophilic additions. Silylated enals exhibited interesting features based on the electronic and steric properties of silyl substituents. The present model computations could assist in the development of new synthetic applications for this class of compounds as they find wider synthetic application.
Enantioselective Installation of Quaternary Centers in Cyclic Oxonitriles
Authors: Gunes Yakup , Arcelik Nejat , Sahin Ertan , Fleming Fraser F. , Altundas Ramazan
Published: September 2015

Quaternary centers are rapidly and selectively installed in a series of seven‐membered and bridged cyclic oxonitriles through conjugate addition of an alkoxide to chloroalkenenitriles, followed by a Claisen rearrangement. Using this strategy, the stereogenic information of the carbinol in secondary allylic alcohols is transferred to the newly generated quaternary center. Experimentally, the sequence rapidly gives alkyl cyanocycloheptanones and bicycloalkanonecarbonitriles in good yield and with high selectivity, in a single synthetic operation.
Comparative Analysis of Fluorine‐Directed Glycosylation Selectivity: Interrogating C2 [OH → F] Substitution in d‐­Glucose and d‐Galactose
Authors: Santschi Nico , Gilmour Ryan
Published: September 2015

The influence of C2 [OH → F] substitution on the stereochemical course of chemical glycosylation was interrogated in both D‐glucose and its C4 epimer D‐galactose. Molecular editing at C2 and configurational inversion at C4 were simultaneously investigated by variable‐temperature glycosylation studies of both systems. Extrapolation of the differences in enthalpic (ΔΔHβα‡) and entropic (ΔΔSβα‡) contributions that discriminate these closely similar systems revealed that deoxofluorination at the C2 position induces an enthalpic bias that augments β‐stereoselection. Intriguingly, the enhanced stereoselectivity of the C4 epimer D‐galactose was found to be entropic in nature. Given the prominence of these scaffolds in chemical biology, delineating the factors that underpin selectivity will be critical in developing novel glycosylation methods and in rationalizing differences with the natural systems post facto.