bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiphase dynamic flash simulations using entropy maximization and application to compressible flow with phase change
Authors: Qiu Lu , Wang Yue , Reitz Rolf D.
Published: June 2014

A isochoric‐isoenergetic flash solver using a direct entropy maximization principle for phase splitting and Gibbs free energy minimization for phase stability is developed. The solver searches for the global stable state in a rigorous and thermodynamically consistent way. The solver is demonstrated to be robust and efficient to handle multiphase flash, even in the vicinity of phase boundaries. Dynamic flash computations and gas dynamics simulations of shock waves are considered for pure ethylene and for binary ethylene‐nitrogen mixtures. The simulations show significantly different shock wave characteristics when phase separation is considered due to intensive energy exchange, compared to the frozen flow limiting single‐phase solution. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3013–3024, 2014
Stable isotopes complement focal individual observations and confirm dietary variability in reddish–gray mouse lemurs (Microcebusgriseorufus) from southwesternMadagascar
Authors: Crowley Brooke E. , Rasoazanabary Emilienne , Godfrey Laurie R.
Published: June 2014

We examine the ecology of reddish‐gray mouse lemurs from three habitats at Beza Mahafaly Special Reserve using focal follows and stable carbon and nitrogen isotope data. Focal observations indicate dietary differences among habitats as well as sexes and seasons. Both sexes consume more arthropods during the rainy season but overall, females consume more sugar‐rich exudates and fruit than males, and individuals from riparian forest consume fewer arthropods and more fruit than those in xeric or dry forest. We ask whether these observations are isotopically detectable. Isotope data support differences between seasons and sexes. Nitrogen isotope values are higher during the rainy season when lemurs consume more arthropods, and higher in males than females, particularly during the dry season. However, differences among populations inferred from focal observations are not fully supported. Lemurs from riparian forest have lower isotope values than those in xeric scrub, but isotope data suggest that lemurs from the dry forest eat the least animal matter and that focal observations overestimated dry forest arthropod consumption. Overall, our results suggest that observational and isotopic data are complementary. Isotope data can be obtained from a larger number of individuals and can quantify ingestion of animal matter, but they apparently cannot quantify the relative consumption of different sugar‐rich foods. Combined focal and isotope data provide valuable insight into the dietary constraints of reddish‐grey mouse lemurs, with implications for their vulnerability to future habitat change. Am J Phys Anthropol 155:77–90, 2014. © 2014 Wiley Periodicals, Inc.
Macrocyclic Protease Inhibitors with Reduced Peptide Character
Authors: Chua Krystle C. H. , Pietsch Markus , Zhang Xiaozhou , Hautmann Stephanie , Chan Hon Y. , Bruning John B. , Gütschow Michael , Abell Andrew D.
Published: June 2014

There is a real need for simple structures that define a β‐strand conformation, a secondary structure that is central to peptide–protein interactions. For example, protease substrates and inhibitors almost universally adopt this geometry on active site binding. A planar pyrrole is used to replace two amino acids of a peptide backbone to generate a simple macrocycle that retains the required geometry for active site binding. The resulting β‐strand templates have reduced peptide character and provide potent protease inhibitors with the attachment of an appropriate amino aldehyde to the C‐terminus. Picomolar inhibitors of cathepsin L and S are reported and the mode of binding of one example to the model protease chymotrypsin is defined by X‐ray crystallography.
Iron Porphyrin Carbenes as Catalytic Intermediates: Structures, Mössbauer and NMR Spectroscopic Properties, and Bonding
Authors: Khade Rahul L. , Fan Wenchao , Ling Yan , Yang Liu , Oldfield Eric , Zhang Yong
Published: June 2014

Iron porphyrin carbenes (IPCs) are thought to be intermediates involved in the metabolism of various xenobiotics by cytochrome P450, as well as in chemical reactions catalyzed by metalloporphyrins and engineered P450s. While early work proposed IPCs to contain FeII, more recent work invokes a double‐bond description of the iron–carbon bond, similar to that found in FeIV porphyrin oxenes. Reported herein is the first quantum chemical investigation of IPC Mössbauer and NMR spectroscopic properties, as well as their electronic structures, together with comparisons to ferrous heme proteins and an FeIV oxene model. The results provide the first accurate predictions of the experimental spectroscopic observables as well as the first theoretical explanation of their electrophilic nature, as deduced from experiment. The preferred resonance structure is FeII←{:C(X)Y}0 and not FeIV{C(X)Y}2−, a result that will facilitate research on IPC reactivities in various chemical and biochemical systems.
Water‐Soluble Triarylboron Compound for ATP Imaging In Vivo Using Analyte‐Induced Finite Aggregation
Authors: Li Xiaoyan , Guo Xudong , Cao Lixia , Xun Zhiqing , Wang Shuangqing , Li Shayu , Li Yi , Yang Guoqiang
Published: June 2014

Adenosine 5′‐triphosphate (ATP) is a multifunctional molecule that participates in many important biological processes. Currently, fluorescence indicators for ATP with high performance are in demand. Reported herein is a novel water‐soluble triarylboron compound which displays an apparent ATP‐dependent fluorescence enhancement when dispersed in water. It can selectively recognize ATP from other bioactive substances in vitro and in vivo. The ATP‐induced finite aggregation endows the indicator with appreciable photostability and superior tolerance to environmental electrolytes. This indicator has been successfully applied to the ATP imaging in NIH/3T3 fibroblast cells. The difference in the ATP levels within the membrane and cytosol is clearly visible.
Molecularly Designed Nanoparticles by Dispersion of Self‐Assembled Organosiloxane‐Based Mesophases
Authors: Sakamoto Shigeru , Tamura Yasuhiro , Hata Hideo , Sakamoto Yasuhiro , Shimojima Atsushi , Kuroda Kazuyuki
Published: June 2014

The design of siloxane‐based nanoparticles is important for many applications. Here we show a novel approach to form core–shell silica nanoparticles of a few nanometers in size through the principle of “dispersion of ordered mesostructures into single nanocomponents”. Self‐assembled siloxane–organic hybrids derived from amphiphilic alkyl‐oligosiloxanes were postsynthetically dispersed in organic solvent to yield uniform nanoparticles consisting of dense lipophilic shells and hydrophilic siloxane cores. In situ encapsulation of fluorescent dyes into the nanoparticles demonstrated their ability to function as nanocarriers.
Gold‐Catalyzed Direct Hydrogenative Coupling of Nitroarenes To Synthesize Aromatic Azo Compounds
Authors: Liu Xiang , Li Hai‐Qian , Ye Sen , Liu Yong‐Mei , He He‐Yong , Cao Yong
Published: June 2014

The azo linkage is a prominent chemical motif which has found numerous applications in materials science, pharmaceuticals, and agrochemicals. Described herein is a sustainable heterogeneous‐gold‐catalyzed synthesis of azo arenes. Available nitroarenes are deoxygenated and linked selectively by the formation of NN bonds using molecular H2 without any external additives. As a result of a unique and remarkable synergy between the metal and support, a facile surface‐mediated condensation of nitroso and hydroxylamine intermediates is enabled, and the desired transformation proceeds in a highly selective manner under mild reaction conditions. The protocol tolerates a large variety of functional groups and offers a general and versatile method for the environmentally friendly synthesis of symmetric or asymmetric aromatic azo compounds.
Thiol‐functionalized fructose‐derived nanoporous carbon as a support for gold nanoparticles and its application for aerobic oxidation of alcohols in water
Authors: Mahyari Mojtaba , Shaabani Ahmad , Behbahani Mohammad , Bagheri Akbar
Published: June 2014

Gold nanoparticles supported on thiol‐functionalized fructose‐derived nanoporous carbon (AuNPs@thiol‐Fru‐d‐NPS) were found to be a simple bench‐top, biocompatible, recyclable and selective catalytic system for the aerobic oxidation of various types of alcohols into their corresponding aldehydes and ketones at room temperature under the environmentally friendly conditions with excellent yields. Copyright © 2014 John Wiley & Sons, Ltd.
Cognitive load imposed by knobology may adversely affect learners' perception of utility in using ultrasonography to learn physical examination skills, but not anatomy
Authors: Jamniczky Heather A. , McLaughlin Kevin , Kaminska Malgorzata E. , Raman Maitreyi , Somayaji Ranjani , Wright Bruce , Ma Irene W. Y.
Published: June 2014

Ultrasonography is increasingly used for teaching anatomy and physical examination skills but its effect on cognitive load is unknown. This study aimed to determine ultrasound's perceived utility for learning, and to investigate the effect of cognitive load on its perceived utility. Consenting first‐year medical students (n = 137) completed ultrasound training that includes a didactic component and four ultrasound‐guided anatomy and physical examination teaching sessions. Learners then completed a survey on comfort with physical examination techniques (three items; alpha = 0.77), perceived utility of ultrasound in learning (two items; alpha = 0.89), and cognitive load on ultrasound use [measured with a validated nine‐point scale (10 items; alpha = 0.88)]. Learners found ultrasound useful for learning for both anatomy and physical examination (mean 4.2 ± 0.9 and 4.4 ± 0.8, respectively; where 1 = very useless and 5 = very useful). Principal components analysis on the cognitive load survey revealed two factors, “image interpretation” and “basic knobology,” which accounted for 60.3% of total variance. Weighted factor scores were not associated with perceived utility in learning anatomy (beta = 0.01, P = 0.62 for “image interpretation” and beta = −0.04, P = 0.33 for “basic knobology”). However, factor score on “knobology” was inversely associated with perceived utility for learning physical examination (beta = −0.06; P = 0.03). While a basic introduction to ultrasound may suffice for teaching anatomy, more training may be required for teaching physical examination. Prior to teaching physical examination skills with ultrasonography, we recommend ensuring that learners have sufficient knobology skills. Anat Sci Educ 8: 197–204. © 2014 American Association of Anatomists.
Label‐Free Logic Modules and Two‐Layer Cascade Based on Stem‐Loop Probes Containing a G‐Quadruplex Domain
Authors: Guo Yahui , Cheng Junjie , Wang Jine , Zhou Xiaodong , Hu Jiming , Pei Renjun
Published: June 2014

A simple, versatile, and label‐free DNA computing strategy was designed by using toehold‐mediated strand displacement and stem‐loop probes. A full set of logic gates (YES, NOT, OR, NAND, AND, INHIBIT, NOR, XOR, XNOR) and a two‐layer logic cascade were constructed. The probes contain a G‐quadruplex domain, which was blocked or unfolded through inputs initiating strand displacement and the obviously distinguishable light‐up fluorescent signal of G‐quadruplex/NMM complex was used as the output readout. The inputs are the disease‐specific nucleotide sequences with potential for clinic diagnosis. The developed versatile computing system based on our label‐free and modular strategy might be adapted in multi‐target diagnosis through DNA hybridization and aptamer‐target interaction.
Whether to enter expressway or not? The impact of new variable message sign information
Authors: Gan Hongcheng , Ye Xin
Published: June 2014

This study develops a random effect panel data logit model that identifies the factors that influence expressway users' decision behavior under a new arterial road variable message sign information service. The new information service provides travel time of both an expressway route and an alternate arterial road route. It is based on the data collected from a stated preference survey of Shanghai drivers. Correlations within repeated choices by the same respondent were addressed. The results show that the random effect model performs well in addressing repeated observations and evidences the existence of common unobserved random factors affecting route choice behaviors of the same respondent. It is shown that drivers' decisions can be significantly influenced by the new information service. Driving experience, travel time saving, and occurrence of expressway accidents serve as positive factors whereas number of traffic lights on the arterial road serves as a negative factor in choosing the arterial road. Private car drivers, employer‐provided car drivers, and taxi drivers value number of traffic lights in a different way. Female drivers are more sensitive to expressway delays. Drivers with rich driving experience and female drivers are more sensitive to number of traffic lights. Copyright © 2014 John Wiley & Sons, Ltd.
Luminescence in Sr4Al14O25:Ce3+ aluminate phosphor
Authors: Nikhare G. N. , Gedam S. C. , Dhoble S. J.
Published: June 2014

Cerium‐doped Sr4Al14O25 phosphor is prepared using a single‐step combustion synthesis and its X‐ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) and thermoluminescence (TL) properties are characterized. XRD reveals the formation of the desired phase in the prepared sample. SEM micrographs of the prepared Sr4Al14O25 phosphor show that the particle size is 10 µm. The prepared Sr4Al14O25, along with Sr4Al14O25:Cex (x = 0.5–5 mol%) shows a PL emission peak at 314 nm under UV excitation of 262 nm wavelength due to 5d → 4f transition. The phosphor is suitable for higher concentrations of Ce ions. The TL glow peak reveals three clearly visible distinct peaks at temperatures around 130, 231 and 336ºC. The three peaks are separated by deconvolution and kinetic parameters calculated using Chen's peak shape method. The calculation shows that the reaction follows second‐order kinetics with activation energy (E) values of 0.52, 0.81 and 1.12 eV, and frequency factor (s) values of 5.58 × 105, 4.53 × 107 and 4.57 × 108 s‐1 for the three individual peaks. Copyright © 2014 John Wiley & Sons, Ltd.
In vivo protective effects of dietary curcumin and capsaicin against alcohol‐induced oxidative stress
Authors: Pyun Chang‐Won , Kim Ji‐Han , Han Kyu‐Ho , Hong Go‐Eun , Lee Chi‐Ho
Published: June 2014

BALB/c mice were exposed to chronic alcohol‐induced oxidative stress by intragastric administration of excessive ethanol (5 g/kg body weight) during the 24‐week period. Curcumin (0.016%) or capsaicin (0.014%) containing diets were fed with or without ethanol treatment in four groups. There was no statistically significant difference in the behavioral test between all groups during the experimental period. Only one alcohol‐treated mouse fed a normal diet showed a behavioral disorder and died before the raising period was completed. There were no effects on the activity of catalase and superoxide dismutase in the brain. However, curcumin or capsaicin treatment prevented alcohol‐induced decline in brain weight. Furthermore, the levels of malondialdehyde and phosphatidylcholine hydroperoxide were significantly reduced in the brain tissue extract. The findings of this study demonstrated and confirmed the antioxidant effect of curcumin and capsaicin against alcohol‐induced oxidative stress, and they suggest a direction for further studies. © 2014 BioFactors, 40(5):494–500, 2014
Raman spectroscopy provides a rapid, non‐invasive method for quantitation of starch in live, unicellular microalgae
Authors: Ji Yuetong , He Yuehui , Cui Yanbin , Wang Tingting , Wang Yun , Li Yuanguang , Huang Wei E. , Xu Jian
Published: June 2014

Conventional methods for quantitation of starch content in cells generally involve starch extraction steps and are usually labor intensive, thus a rapid and non‐invasive method will be valuable. Using the starch‐producing unicellular microalga Chlamydomonas reinhardtii as a model, we employed a customized Raman spectrometer to capture the Raman spectra of individual single cells under distinct culture conditions and along various growth stages. The results revealed a nearly linear correlation (R2 = 0.9893) between the signal intensity at 478 cm–1 and the starch content of the cells. We validated the specific correlation by showing that the starch‐associated Raman peaks were eliminated in a mutant strain where the AGPase (ADP‐glucose pyrophosphorylase) gene was disrupted and consequentially the biosynthesis of starch blocked. Furthermore, the method was validated in an industrial algal strain of Chlorella pyrenoidosa. This is the first demonstration of starch quantitation in individual live cells. Compared to existing cellular starch quantitation methods, this single‐cell Raman spectra‐based approach is rapid, label‐free, non‐invasive, culture‐independent, low‐cost, and potentially able to simultaneously track multiple metabolites in individual live cells, therefore should enable many new applications.
Identification of critical parameters in liquid enzyme‐catalyzed biodiesel production
Authors: Nordblad Mathias , Silva Vanessa T. L. , Nielsen Per Munk , Woodley John M.
Published: June 2014

Callera™ Trans L, a liquid formulation of Thermomyces lanuginosus lipase, has recently shown great promise as a cost‐efficient catalyst for methanolysis of triglyceride substrates, specifically in the BioFAME process. However, identifying the right combination of temperature and concentrations of catalyst, water and methanol to realize the full potential of the reaction system has remained a challenge. This study presents an investigation of the impact of temperature, enzyme and water concentration on the reaction, as well as the effect of methanol feed rate for the conversion of rapeseed oil in a fed‐batch reaction system. It was observed that the reaction can be divided into two distinct parts. The first part of the reaction, during which primarily tri‐ and diglycerides are converted, proceeded at a high rate and thus required a high rate of methanol supply. The second part of the reaction, where the remaining di‐ and monoglycerides are converted, proceeded at a much lower rate. Consequently, it is necessary to reduce the methanol feed rate during the latter part of the reaction to avoid inhibition or even inactivation of the enzyme. Since the second part of the reaction occupied most of the 24‐h reaction time, it was concluded that this is the part of the process where further development efforts should be targeted. This point was demonstrated by partially substituting the catalyst with a lipase with a different specificity, which enhanced the performance during the second phase of the reaction. Biotechnol. Bioeng. 2014;111: 2446–2453. © 2014 Wiley Periodicals, Inc.
Analysis and pharmacokinetic study of polyphyllin H in beagle dog plasma after oral administration of Rhizoma Paridis extracts by LC‐MS/MS
Authors: Yin Xingbin , Lin Longfei , Shen Mingrui , Zhai Yujing , Cao Sali , Fu Jing , Li Xuechun , Yang Chunjing , Xia Zhenwen , Zhao Yang , Li Shangxin , Bai Ying , Xue Dan , Ni Jian
Published: June 2014

A highly sensitive, rapid assay method has been developed and validated for the analysis of polyphyllin H in beagle dog plasma with liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the positive‐ion mode. The assay procedure involves extraction of polyphyllin H and ginsenoside Re (IS) from beagle dog plasma. Chromatographic separation was carried out on an Agilent Zorbax XDB‐C18 (100 × 2.1 mm, 1.8μm) column by isocratic elution with acetonitrile and water (50:50, v/v) at a flow rate of 0.25 mL/min with a total run time of 2.5 min. The MS/MS ion transitions monitored were 870.46 → 869.6 for polyphyllin H and 947.12 → 969.60 for IS. Linear responses were obtained for polyphyllin H ranging from 1 to 50 ng/mL. The intra‐and inter‐day precisions (RSDs) were <1.77 and 3.39% and the extraction recovery ranged from 91.89 to 93.33% with RSD <2.68%. Stability studies showed that polyphyllin H was stable in the preparation and analytical process. The results indicated that the validated method was successfully used to determine the concentration–time profiles of polyphyllin H. Copyright © 2014 John Wiley & Sons, Ltd.
A systematic review of microRNA expression profiling studies in human gastric cancer
Authors: Shrestha Sirjana , Hsu Sheng‐Da , Huang Wei‐Yun , Huang Hsi‐Yuan , Chen WenLiang , Weng Shun‐Long , Huang Hsien‐Da
Published: June 2014

Gastric cancer (GC) is the second leading cause of global cancer mortality. Most GC patients are diagnosed with advanced‐stage disease and show extremely poor prognosis. All of the GC research has a common interest to search for the specific and sensitive biomarkers for early diagnosis of GC. Number of microRNAs play important role in GC. We carried out a systematic review of published miRNA profiling studies that compared the miRNA expression profiles between GC tissues and paired noncancerous gastric tissue. A vote‐counting strategy was followed with the collection of information like total number of studies reporting differential expression of miRNA, total number of tissue samples used in the studies, direction of differential expression and fold change. A total of 352 differentially expressed microRNAs were reported in the 14 microRNA expression profiling studies that compared GC tissues with normal tissues with 120 microRNAs reported at least in two studies. In the group of consistently reported microRNAs, miR‐21 was reported upregulated in 10 studies followed by miR‐25, miR‐92, and miR‐223 upregulated in eight studies. MiR‐375 and miR‐148a were found downregulated in six and five studies, respectively, followed by miR‐638 in four studies. MiR‐107 and miR‐103 were reported in nine and eight studies, respectively, but their expression were inconsistent. From this study, the most consistently reported upregulated microRNA was found to be miR‐21. This systematic review study of human GC microRNA expression profiling studies would provide information on microRNAs with potential role as the biomarkers in gastric cancer.
African American women's perceptions of cancer clinical trials
Authors: Haynes‐Maslow Lindsey , Godley Paul , Dimartino Lisa , White Brandolyn , Odom Janice , Richmond Alan , Carpenter William
Published: June 2014

Cancer clinical trials are important for resolving cancer health disparities for several reasons; however, clinical trial participation among African Americans is significantly lower than Caucasians. This study engaged focus groups of 82 female African American cancer survivors or cancer caregivers, including those in better resourced, more urban areas and less resourced, more rural areas. Informed by an integrated conceptual model, the focus groups examined perceptions of cancer clinical trials and identified leverage points that future interventions may use to improve enrollment rates. Study findings highlight variation in community knowledge regarding cancer clinical trials, and the importance of community education regarding clinical trials and overcoming historical stigma associated with clinical research specifically and the health care system more generally. Study participants commented on the centrality of churches in their communities, and thus the promise of the church as loci of such education. Findings also suggested the value of informed community leaders as community information sources, including community members who have a previous diagnosis of cancer and clinical trial experience. The sample size and location of the focus groups may limit the generalizability of the results. Since the women in the focus groups were either cancer survivors or caregivers, they may have different experiences than nonparticipants who lack the close connection with cancer. Trust in the health system and in one's physician was seen as important factors associated with patient willingness to enroll in clinical trials, and participants suggested that physicians who were compassionate and who engaged and educated their patients would build important trust requisite for patient participation in clinical trials.
In Vivo Structure–Activity Relationship Studies Support Allosteric Targeting of a Dual Specificity Phosphatase
Authors: Korotchenko Vasiliy N. , Saydmohammed Manush , Vollmer Laura L. , Bakan Ahmet , Sheetz Kyle , Debiec Karl T. , Greene Kristina A. , Agliori Christine S. , Bahar Ivet , Day Billy W. , Vogt Andreas , Tsang Michael
Published: June 2014

Dual specificity phosphatase 6 (DUSP6) functions as a feedback attenuator of fibroblast growth factor signaling during development. In vitro high throughput chemical screening attempts to discover DUSP6 inhibitors have yielded limited success. However, in vivo whole‐organism screens of zebrafish identified compound 1 (BCI) as an allosteric inhibitor of DUSP6. Here we designed and synthesized a panel of analogues to define the structure–activity relationship (SAR) of DUSP6 inhibition. In vivo high‐content analysis in transgenic zebrafish, coupled with cell‐based chemical complementation assays, identified structural features of the pharmacophore of 1 that were essential for biological activity. In vitro assays of DUSP hyperactivation corroborated the results from in vivo and cellular SAR. The results reinforce the notion that DUSPs are druggable through allosteric mechanisms and illustrate the utility of zebrafish as a model organism for in vivo SAR analyses.
Rhamnose Glycoconjugates for the Recruitment of Endogenous Anti‐Carbohydrate Antibodies to Tumor Cells
Authors: Sheridan Rachael T. C. , Hudon Jonathan , Hank Jacquelyn A. , Sondel Paul M. , Kiessling Laura L.
Published: June 2014

Immunotherapy is a promising strategy for targeting tumors. One emerging approach is to harness the immune effector functions of natural antibodies to destroy tumor cells. Dinitrophenyl (DNP) and the galactose‐α‐1,3‐galactose (αGal) epitope are two haptens that bind endogenous antibodies. One potential alternative is the deoxysugar L‐rhamnose. We compared these candidates by using a biosensor assay to evaluate human sera for endogenous antibody concentration, antibody isotype distribution, and longevity of antibody–hapten interactions. Antibodies recognizing α‐rhamnose are of equal or greater abundance and affinity as those recognizing αGal. Moreover, both rhamnose and αGal epitopes are more effective than DNP at recruiting the IgG antibody subtype. Exposure of tumor cells to rhamnose‐bearing glycolipids and human serum promotes complement‐mediated cytotoxicity. These data highlight the utility of α‐rhamnose‐containing glycoconjugates to direct the immune system to target cells.
Copper‐Free Click Reactions with Polar Bicyclononyne Derivatives for Modulation of Cellular Imaging
Authors: Leunissen E. H. P. , Meuleners M. H. L. , Verkade J. M. M. , Dommerholt J. , Hoenderop J. G. J. , van Delft F. L.
Published: June 2014

The ability of cells to incorporate azidosugars metabolically is a useful tool for extracellular glycan labelling. The exposed azide moiety can covalently react with alkynes, such as bicyclo[6.1.0]nonyne (BCN), by strain‐promoted alkyne–azide cycloaddition (SPAAC). However, the use of SPAAC can be hampered by low specificity of the cycloalkyne. In this article we describe the synthesis of more polar BCN derivatives and their properties for selective cellular glycan labelling. The new polar derivatives [amino‐BCN, glutarylamino‐BCN and bis(hydroxymethyl)‐BCN] display reaction rates similar to those of BCN and are less cell‐permeable. The labelling specificity in HEK293 cells is greater than that of BCN, as determined by confocal microscopy and flow cytometry. Interestingly, amino‐BCN appears to be highly specific for the Golgi apparatus. In addition, the polar BCN derivatives label the N‐glycan of the membrane calcium channel TRPV5 in HEK293 cells with significantly enhanced signal‐to‐noise ratios.
Surface Control and Photocatalytic Activity of Branched Silver Orthophosphate Dendrites
Authors: Wang Jun , Lou Sunqi , Sun Peng , Wang LiLi , Teng Yiran , Chen Mindong , Teng Fei
Published: June 2014

Surface control is important to improve the adsorption, reactivity, and selectivity of materials. Limited by thermodynamic crystal habit, however, it is still a big challenge to control active surfaces simply and effectively. In this report, we introduce an innovative branching‐growth methodology to control the surfaces of Ag3PO4 without the use of screening agents or templates. Typically, an in situ seed‐induced branching growth strategy is developed to achieve the surface control of silver orthophosphate, in which the crystal growth changes from mass‐transport‐limited branching growth to pH‐dependent faceting growth. As a result, numerous unprecedented, highly branched Ag3PO4 dendrites have been acquired. The apparent reaction rate constants of these dendrites are 2.55–3.76 times higher than conventional cubes for the degradation of rhodamine B dye. This study provides a new, effective avenue to control the surfaces of materials, which has made a big breakthrough to the improvement of the performances of materials. This is important for us to obtain materials or devices with greatly improved performances.
Evidences of Two‐Regimes in the Measurement of Ru Particle Size Effect for CO Dissociation during Fischer–Tropsch Synthesis
Authors: González‐Carballo Juan M. , Pérez‐Alonso Francisco J. , Ojeda Manuel , García‐García F. Javier , Fierro José Luis G. , Rojas Sergio
Published: June 2014

This work assesses the effect of the particle size for the Fischer–Tropsch synthesis with catalysts based on Ru particles between 4 and 71 nm. CO dissociation is a structure‐sensitive reaction, that is, the turnover frequency (TOF) is affected by Ru particle size. Herein it is demonstrated that two regimes exist for the effect of Ru particle size. On the one hand, the expected relationship of TOF with particle size, that is, the TOF increases with Ru particles <10 nm, is only observed if measured at steady‐state conditions. On the contrary, the TOF increases constantly with Ru particle size if measured at the initial state. However, the TOF measured for catalysts with Ru particles >10 nm declines during time on stream. These observations suggest that two regimes for the measurement of CO dissociation exist during Fischer–Tropsch synthesis. The reason for this is that two sites for CO dissociation on the Ru particles >10 nm exist at the initial state, terraces and step‐edges, but the latter ones deactivate during time on stream.
Sterilization of Medical Products from Collagen by Means of Supercritical CO2
Authors: Herdegen Volker , Felix Alexander , Haseneder Roland , Repke Jens‐Uwe , Leppchen‐Fröhlich Kathrin , Prade Ina , Meyer Michael
Published: June 2014

Collagen is increasingly used as material for medical devices because of its excellent biocompatibility. To achieve long‐term durability, the collagen materials are dried and subsequently sterilized. Most common sterilization methods are unsuitable as they cause denaturation. Currently, only ethylenoxide or γ irradiation preserves the microscopic and macroscopic collagen structure. However, both methods require high safety standards and include the risk of uncontrolled crosslinking or cleavage of protein chains. Here, supercritical carbon dioxide is used for the sterilization of different collagen devices. Thereby, the influence of pressure, temperature, sterilization aid and dosage, and different operation modes is determined. The method is a promising alternative to existing sterilization techniques.
Porous Perovskite Fibers – Preparation by Wet Phase Inversion Spinning and Catalytic Activity
Authors: Kaiser Sandy , Reichelt Erik , Gebhardt Sylvia E. , Jahn Matthias , Michaelis Alexander
Published: June 2014

Porous perovskite (LaMnO3) fibers were prepared by means of wet phase inversion spinning. The influence of different spinning procedures, slurry and coagulation bath composition on fiber shape and pore morphology was studied. The catalytic activity of the prepared fibers was tested for carbon monoxide oxidation as a model reaction in a differential recycle reactor. The results revealed that by suitable choice of process conditions porous catalytically active fibers can be prepared. Catalytic measurements confirmed that the catalytic fibers exhibit an open structure that allows full utilization of the catalytically active surface without intraparticle diffusional limitations.
Multielectron, Multistep Molecular Catalysis of Electrochemical Reactions: Benchmarking of Homogeneous Catalysts
Authors: Costentin Cyrille , Savéant Jean‐Michel
Published: June 2014

Current–potential responses in cyclic voltammetry and in preparative‐scale electrolysis are established for two‐electron two‐step homogeneous molecular catalysis after systematic categorization of the various possible reaction schemes. They allow the derivation of catalytic Tafel plots, reflecting the intrinsic properties of the catalysts independent of contingent electrolysis parameters. They serve as a rational basis for benchmarking catalysts of the same electrochemical reaction within the same log(turnover frequency) versus overpotential plane of merit.
Calibration transfer of near‐infrared spectra for extraction of informative components from spectra with canonical correlation analysis
Authors: Zheng Kaiyi , Zhang Xuan , Iqbal Jibran , Fan Wei , Wu Ting , Du Yiping , Liang Yizeng
Published: June 2014

A new calibration transfer method that applies canonical correlation analysis (CCA) to transfer the informative components extracted from a spectral dataset is proposed to reduce the interference of noise, background and non‐predicted properties. This method employs the partial least squares method to extract the informative components related to the predicted properties from the raw spectra and then corrects the informative components based on CCA. The performance of this algorithm was tested using three pairs of spectra batches: two pairs of corn spectra and one pair of tri‐component solvent spectra. The results showed that this method can significantly reduce prediction errors compared with CCA and piecewise direct standardization. Copyright © 2014 John Wiley & Sons, Ltd.
Exploring Strain‐Promoted 1,3‐Dipolar Cycloadditions of End Functionalized Polymers
Authors: Ledin Petr A. , Kolishetti Nagesh , Hudlikar Manish S. , Boons Geert‐Jan
Published: June 2014

Strain‐promoted 1,3‐dipolar cycloaddition of cyclooctynes with 1,3‐dipoles such as azides, nitrones, and nitrile oxides, are of interest for the functionalization of polymers. In this study, we have explored the use of a 4‐dibenzocyclooctynol (DIBO)‐containing chain transfer agent in reversible addition–fragmentation chain transfer polymerizations. The controlled radical polymerization resulted in well‐defined DIBO‐terminating polymers that could be modified by 1,3‐dipolar cycloadditions using nitrones, nitrile oxides, and azides having a hydrophilic moiety. The self‐assembly properties of the resulting block copolymers have been examined. The versatility of the methodology was further demonstrated by the controlled preparation of gold nanoparticles coated with the DIBO‐containing polymers to produce materials that can be further modified by strain‐promoted cycloadditions.
The Donor‐Stabilized Silylene Bis[N,N′‐diisopropylbenzamidinato(−)]silicon(II): Synthesis, Electronic Structure, and Reactivity
Authors: Junold Konstantin , Nutz Marco , Baus Johannes A. , Burschka Christian , Fonseca Guerra Célia , Bickelhaupt F. Matthias , Tacke Reinhold
Published: June 2014

A convenient and robust synthesis of bis[N,N′‐diisopropylbenzamidinato(−)]silicon(II) (1), a donor‐stabilized silylene, has been developed (35 g scale). To get further information about the reactivity profile of 1, a series of oxidative addition reactions were studied. Treatment of 1 with PhSeSePh (SeSe bond activation), C6F6 (CF activation), and CO2 (CO activation/cycloaddition) yielded the neutral six‐coordinate silicon(IV) complexes 10, 11, and 13, respectively. Treatment of 1 with N2O resulted in the formation of the dinuclear five‐coordinate silicon(IV) complex 12 (oxidative addition/dimerization), which contains a four‐membered Si2O2 ring. Compounds 10–13 were characterized by NMR spectroscopic studies in the solid state and in solution and by crystal structure analyses. Silylene 1 is three‐coordinate in the solid state (from crystal structure analysis) and exists as the four‐coordinate isomer 1′ in benzene solution (from computational studies). Based on state‐of‐the‐art relativistic DFT analyses, the four‐coordinate species 1′ was demonstrated to be the thermodynamically favored isomer in benzene solution (favored by ΔG=6.6 kcal mol−1 over the three‐coordinate species 1). The reason for this was studied by bonding analyses of 1 and 1′. Furthermore, the 29Si NMR chemical shifts of 1 and 1′ were computed, and in the case of 1′ it was analyzed how this NMR spectroscopic parameter is affected by solvation. These studies further supported the assumption that the silylene is four‐coordinate in solution.
ChemInform Abstract: Perovskite‐Based Hybrid Solar Cells Exceeding 10% Efficiency with High Reproducibility Using a Thin Film Sandwich Approach.
Authors: Conings Bert , Baeten Linny , De Dobbelaere Christopher , D'Haen Jan , Manca Jean , Boyen Hans‐Gerd
Published: June 2014

Hybrid solar cells based on the mixed metal halide perovskite absorber MeNH3PbI2Cl, sandwiched between selective contacts of TiO2 and poly‐3‐hexylthiophene show unprecedented reproducibility with efficiencies up to 10.8%.
ChemInform Abstract: Challenges on Molecular Aspects of Dealumination and Desilication of Zeolites
Authors: Silaghi Marius‐Christian , Chizallet Celine , Raybaud Pascal
Published: June 2014

Review: 119 refs.
Künstliche Nukleinsäure als molekulare Schere
Authors: Feil Sylvia
Published: June 2014

Spiegelbildliche Enzyme aus Nukleinsäuren zerschneiden RNA‐Moleküle gezielt und schalten sie damit aus. Werden Krankheiten durch überexprimierte Gene verursacht, könnten diese Spiegelzyme ein neues Werkzeug zum Gene‐Silencing sein [1].
Entrepreneurial capacities as antecedents of business performance in Brazilian firms
Authors: Jiménez Daniel Jiménez , Cegarra‐Navarro Juan Gabriel , Gattermann Perin Marcelo , Sampaio Claudio Hoffmann , Lengler Jorge Bertinetti
Published: June 2014

We investigate the relationship between entrepreneurial capacities and firm performance. More specifically, we investigate the effects of radical innovation and learning orientation on business performance. We test the effects of entrepreneurial orientation on learning orientation and radical innovation. The results suggest that radical product innovation and companies' orientation to learn have a positive effect on organizational performance. Additionally, we find that entrepreneurial orientation positively influences a firm's capability to learn and innovate. Our findings also show a direct effect of learning orientation on radical innovation, which means that companies with a higher proclivity to learn are more likely to create products and processes, representing a major departure from the state of current knowledge. Copyright © 2014 ASAC. Published by John Wiley & Sons, Ltd.
MNE practice transfer as a process of institutional change
Authors: Edwards Gwyneth , Molz Rick
Published: June 2014

We build upon current theory on strategic organizational practice transfer in multinational firms by incorporating the agency of actors and applying an institutional lens to the transfer process. Our theoretical analysis suggests that practice transfer is a process of institutional change that leads not only to practice adoption, adaptation, or nonadoption, but also to reconstruction. We argue that when contradictions exist within and across institutional environments, misaligned interests motivate actors to engage in praxis. As a parent‐subsidiary coalition, these actors reconstruct the practice by transcending the multitude of institutional environments that comprise the institutional system. Our process theory provides insight into how less powerful subsidiary actors engage in praxis to extend knowledge and build new capabilities within the firm. Copyright © 2014 ASAC. Published by John Wiley & Sons, Ltd.
New Ligands for Copper‐Catalyzed CN Coupling Reactions at Gentle Temperature
Authors: Su Jinyue , Qiu Yatao , Jiang Sheng , Zhang Dayong
Published: June 2014

Pyridin‐2‐ol‐N‐oxide was designed as an efficient ligand for the coupling reaction of aryl iodides, aryl bromides and aryl chlorides, respectively, with primary amines, cyclic secondary amines or N‐containing heterocycles at room or moderate temperature. The catalytic system showed great functional groups tolerance and excellent selective reactivity.
Boron‐Oxygen Bond Cleavage of Pinacolborane and Catecholborane Mediated by a Scandium Phosphinidene Complex
Authors: Wang Wei , Lv Yingdong , Gou Xiaofeng , Leng Xuebing , Chen Yaofeng
Published: June 2014

Reactions of bis‐scandium bridged phosphinidene complex, [LSc(μ‐PAr)]2 (L=MeC(NDIPP)CHC(Me)(N‐CH2CH2N(iPr)2), DIPP=2,6‐(iPr)2C6H3; Ar=2,6‐Me2C6H3) (1), with pinacolborane, catecholborane, and 9‐borabicyclo[3.3.1]nonane (9‐BBN) are reported. Complex 1 reacts with pinacolborane and catecholborane to give scandium pinacolate (2) and catecholate (3), showing BO bond cleavage. These two scandium complexes contain an unusual [P(Ar)B(H)P(Ar)]2− dianion, which displays a μ‐η2:η2 coordination model. On the other hand, reaction of complex 1 with 9‐BBN affords the BH bond cleavage product, 1,3‐diphospha‐2,4‐diboracyclobutane (4).
Carboxylatopillarene‐Modified Reduced Graphene Oxides with High Water Dispersibility for Fluorescent Dye Sensing
Authors: Zhou Ting , Yu Hao , Liu Mingqiang , Yang Ying‐Wei
Published: June 2014

Carboxylated pillar[5]arene (CP5) macrocycles were modified onto the surface of reduced graphene oxide (RGO) via covalent bonds to form new pillarene‐functionalized RGO nanosheets, i.e., RGO‐CP5. The obtained RGO‐CP5 nanosheets capable of molecular recognition exhibited much better water‐dispersibility and enhanced fluorescence‐quenching property as compared with native RGO. This new sensing platform holds great potentials in the sensing and detection of analytes, such as organic dye molecules and pesticides, in aqueous solutions.
The value of the “suspicious for urothelial carcinoma” cytology category: A correlative study of 4 years including 337 patients
Authors: Ton Nu Tuyet Nhung , Kassouf Wassim , Ahmadi‐Kaliji Babak , Charbonneau Michele , Auger Manon , Brimo Fadi
Published: June 2014

BACKGROUND

The terminology used in reporting urine cytology lacks uniformity and the significance of the “atypical” and “suspicious” categories is still not well established. This results in variable clinical follow‐up and management of those cases. The authors sought to investigate the prognostic value of a diagnosis of “suspicious for high‐grade urothelial carcinoma” (HGUCA).

METHODS

All cases with a “suspicious” or “positive” cytological diagnosis spanning 4 years were included and correlated with the subsequent biopsies obtained within 6 months of urine collection.

RESULTS

A total of 447 correlative events (57% positive and 43% suspicious) corresponding to 773 cytology specimens and 337 patients were included. The morphology of the “suspicious” cells was similar to what has recently been reported in the literature as “atypical urothelial cells, cannot exclude HGUCA.” A “suspicious” diagnosis was more often rendered than a “positive” one in voided specimens (80% vs 65%, respectively). The mean interval between cytology and biopsy was 31 days. On follow‐up, 92% of “suspicious” diagnoses (176 of 191 diagnoses) and 90% of “positive” diagnoses (230 of 256 diagnoses) were found to have a biopsy with a diagnosis of carcinoma (low grade or high grade). A diagnosis of HGUCA followed a “suspicious” and a “positive” diagnosis in 79% and 86% of cases, respectively.

CONCLUSIONS

A “suspicious” diagnosis as defined in the current study warrants close investigations and repeat biopsy to rule out HGUCA. In addition, the findings of the current study raise the question of the need for quantitative criteria for diagnosing HGUCA on cytology. Cancer (Cancer Cytopathol) 2014;122:796–803. © 2014 American Cancer Society.
Cis‐Glyco‐Fused Benzopyran Derivatives as Hit Compounds for the Development of Therapeutic and Diagnostic Tools against Neurodegenerative Diseases
Authors: Merlo Silvia , Sironi Erika , Colombo Laura , Cardona Francisco , Martorana Alessandra M. , Salmona Mario , La Ferla Barbara , Airoldi Cristina
Published: June 2014

Oligomeric and fibrillar aggregates generated by amyloid‐β (Aβ) and prion protein (PrP) peptides are amongst the principal components of amyloid plaques found post mortem in patients suffering from Alzheimer’s disease and mammalian prion diseases. Hence these amyloid peptides represent major molecular targets to develop potential drugs and diagnostic tools for the above‐mentioned neurodegenerative diseases. Recently, a small library of cis‐glyco‐fused benzopyran compounds has been synthesized by us, and their ability to recognize and bind Aβ peptide oligomers and stain Aβ deposits was demonstrated. By exploiting the structural similarity between Aβ and PrP aggregates, herein the interaction of these benzopyran molecules with PrP oligomers and their inhibition of the PrP aggregation process that leads to amyloid fibril formation are investigated. Finally, the in vitro staining of PrP fibrils is achieved with a fluorescently labeled cis‐glyco‐fused benzopyran derivative able to cross a model of the blood–brain barrier.
Porous Cube‐Aggregated Co3O4 Microsphere‐Supported Gold Nanoparticles for Oxidation of Carbon Monoxide and Toluene
Authors: Yang Huanggen , Dai Hongxing , Deng Jiguang , Xie Shaohua , Han Wen , Tan Wei , Jiang Yang , Au Chak Tong
Published: June 2014

Porous cube‐aggregated monodisperse Co3O4 microspheres and their supported gold (xAu/Co3O4 microsphere, x=1.6–7.4 wt %) nanoparticles (NPs) were fabricated using the glycerol‐assisted solvothermal and polyvinyl alcohol‐protected reduction methods. Physicochemical properties of the materials were characterized by means of numerous analytical techniques, and their catalytic activities were evaluated for the oxidation of toluene and CO. It is shown that the cubic Co3O4 microspheres were composed of aggregated cubes with a porous structure. The gold NPs with a size of 3.2–3.9 nm were uniformly deposited on the surface of Co3O4 microspheres. Among the Co3O4 microsphere and xAu/Co3O4 microsphere samples, the 7.4Au/Co3O4 microspheres performed the best, giving T90 % values (the temperature required for achieving a CO or toluene conversion of 90 % at a weight hourly space velocity of 20 000 mL g−1 h−1) of −8 and 250 °C for CO and toluene oxidation, respectively. In the case of 3.0 vol % water vapor introduction, a positive effect on CO oxidation and a small negative effect on toluene oxidation were observed over the 7.4Au/Co3O4 microsphere sample. The apparent activation energies obtained over the xAu/Co3O4 microsphere samples were in the ranges of 40.7–53.6 kJ mol−1 for toluene oxidation and 21.6–34.6 kJ mol−1 for CO oxidation. It is concluded that the higher oxygen adspecies concentration, better low‐temperature reducibility, and stronger interaction between gold NPs and Co3O4 as well as the porous microspherical structure were responsible for the excellent catalytic performance of 7.4Au/Co3O4 microsphere.