bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of media‐embedded heuristics in achieving online readership popularity
Authors: Du Helen S.
Published: October 2013

Readership popularity has been an important proxy for success for many emerging online interactive media sites. Given the exponential growth of new web applications and services, and the intense competition among them, attaining and retaining popularity are difficult. One possible approach to this problem is to enhance the competitiveness of a web presence by using appropriate web design mechanisms. Research in this area has mainly focused on technological issues and usability studies. Few studies have paid attention to the socially constructed meaning (cognition) that is embedded in the context of media. Drawing on the heuristic model from the social cognition perspective, the author posits that source credibility and content freshness are two important media‐embedded heuristics potentially influential to the readership popularity of online interactive media sites. The content analysis results of 100 leading weblogs strongly supported this hypotheses. Key quantitative findings were also consistent with the qualitative evidence provided by 28 expert practitioners. This study expands our understanding of the related constructs from a social cognition perspective and calls for design attention to influential media‐embedded traits when developing online interactive media and related websites.
Light Emission in Water‐Containing Cocrystals: the Influence of Water Molecules on the Fluorescence Properties of a Schiff‐Base Molecule
Authors: Zhou Feng , Tan Pengli , Ma Yong , Li Youyong , Li Najun , Li Hua , Wang Lihua , Gu Hongwei , Xu Qingfeng , Lu Jianmei
Published: October 2013

In the presence or absence of water, a Schiff‐base compound, 4‐amino‐3‐(2‐(2‐hydroxybenzylidene)hydrazinyl)‐1H‐1,2,4‐triazole‐5(4H)‐thione (HATT), forms different crystalline states (HATT, HATT⋅2 H2O, and a lamellar structure, m‐HATT⋅n H2O), which show different luminescence emission properties. Herein, we investigate the emission of HATT and the role of water molecules. A water molecule, which acts as both a hydrogen‐bond acceptor and ‐donor, enlarges the distance between adjacent HATT molecules and hinders non‐radiative decay pathways.
IMC–PID Design: Analytical Optimization for Performance/Robustness Tradeoff Tuning for Servo/Regulation Mode
Authors: Jin Qi‐bing , Liu Qie , Wang Qi , Li Si‐nian , Wang Zhu
Published: October 2013

This paper addresses the analytical design of a one‐degree‐of‐freedom (1‐DoF) robust proportional–integral–derivative (PID) controller for the servo/regulation mode in line with the enhanced internal model control (IMC) principle based on a first order plus dead time (FOPDT) model. The proposed enhanced IMC–PID can provide acceptable performance both for set‐point tracking and for load disturbance rejection. The design procedure is formulated as a constrained optimization problem, in which the robustness of the system is adequately considered. Therefore, the resulting PID controller gives optimal performance with an exact selected robustness degree. Illustrative examples are given to show the effectiveness and merits of the analytical tuning rules for a wide range of plants.
Phenol removal from refinery wastewater by mutant recombinant horseradish peroxidase
Authors: Asad Sedigheh , Dabirmanesh Bahareh , Khajeh Khosro
Published: October 2013

Application of mutated recombinant horseradish peroxidase (HRP) for phenol removal from refinery effluents is reported. Recombinant HRP produced in Escherichia coli suffers from the disadvantage of lacking glycosylation, which affects its catalytic efficiency and stability toward inactivating parameters such as increased temperature and enhanced amounts of hydrogen peroxide. In the present study, the previously reported variant (in which Asn268 was substituted with Asp, N268D) with improved stability characteristics and catalytic efficiency was used to remove phenol from a petroleum refinery effluent. The presence and removal of phenol was studied by high‐performance liquid chromatography; the precipitated oxidized phenol was also observed and removed from the sample by centrifugation. Results showed that the N268D variant can remove 61%, 67%, and 81% of phenol from effluent in 1, 2, and 16 H, respectively. By exploiting the N268D mutant, removal of 50% phenol could be achieved in 42 Min, which was more than 22 times less than the treatment time required by native recombinant enzyme.
Optimal durations of single exposures to a frequency‐modulated magnetic field immediately after bisection in planarian predict final growth values
Authors: Tessaro Lucas W.E. , Persinger Michael A.
Published: October 2013

Planarian (Dugesia tigrinia) were exposed to a frequency‐modulated (“Thomas”), patterned electromagnetic field (EMF) immediately following transection through the pharynx. Subjects were exposed from 15 min to 3 h as well as single versus repeated exposures. Results from multiple experiments indicated that those planaria exposed from 45 to 90 min regenerated at significantly higher rates than those exposed less than 45 min. In addition, the study revealed that exposures greater than 45 min were not significantly different beyond this inflection point. We suggest that this particular pattern of EMF is capable of inducing biochemical pathways associated with cell proliferation, in particular the p38‐MAPK and hsp70 pathways. Bioelectromagnetics 34:613–617, 2013. © 2013 Wiley Periodicals, Inc.
The interaction between cepharanthine and two serum albumins: multiple spectroscopic and chemometric investigations
Authors: Cheng Zhengjun , Liu Rong , Jiang Xiaohui , Xu Qianyong
Published: October 2013

The binding modes of cepharanthine (CEPT) with bovine serum albumin (BSA) and human serum albumin (HSA) have been established by reproducing physiological conditions, which is very important to understand the pharmacokinetics and toxicity of CEPT. These spectral data were further analyzed by the multivariate curve resolution‐alternating least squares method. Moreover, the concentration profiles and pure spectra of three species (BSA/HSA, CEPT and CEPT–BSA/HSA) and the apparent equilibrium constants Kapp were evaluated. The experimental results showed that CEPT could quench the fluorescence intensity of BSA/HSA by a combined quenching (static and dynamic) procedure. The binding constant (K), the thermodynamic parameters (ΔG, ΔH and ΔS) and binding subdomain were measured, and indicated that CEPT could spontaneously bind to BSA/HSA on subdomain IIA through the hydrophobic interactions. The effect of CEPT on the secondary structure of proteins has been analyzed by circular dichroism, 3D fluorescence and Fourier transform infrared spectra. The binding distance between CEPT and tryptophan of BSA/HSA was 2.305/1.749 nm, which is based on the Förster resonance energy transfer theory. Copyright © 2013 John Wiley & Sons, Ltd.
A new quaternary photoluminescence enhancement system of Eu−N‐(o‐vanillin)‐1,8‐diaminonaphthalene−1,10‐phenanthroline−Zn and its application in determining trace amounts of europium and zinc
Authors: Zhou Yunshan , Ahmad Waqar , An Yugang , Zhang Lijuan , Zheng Xiaorui
Published: October 2013

A new sensitive quaternary photoluminescence enhancement system has been successfully developed to determine trace amounts of Eu3+and Zn2+. The photoluminescence intensity of Eu − N‐(o‐vanilin)‐1,8‐diaminonaphthalene systems was greatly increased by the addition of specific concentrations of 1, 10‐phenanthroline and Zn2+. The excitation and emission wavelengths were 274 and 617 nm, respectively. Under optimal system conditions, the photoluminescence intensity showed a linear response toward Eu3+in the range of 5.0 × 10–6 ~ 2.0 × 10–5 M with a limit of detection (= 2.2 × 10–9 M) and the photoluminescence intensity of the system decreased linearly by increasing the Zn2+concentration in the range of 5.0 × 10–8 ~ 1.0 × 10–6 M with a limit of detection (= 8.8 × 10–11 M). This system was successfully applied for the determination of trace amounts of Eu3+in a high purity La2O3matrix and in the synthetic rare earth oxide mixture, and of Zn2+in a high purity Mg(NO3)2 · 6H2O matrix and in synthetic coexisting ionic matrixes. The energy transfer mechanism, photoluminescence enhancement of the system and interference of other lanthanide ions and common coexisting ions were also studied in detail. Copyright © 2013 John Wiley & Sons, Ltd.
Applications of cell‐free protein synthesis in synthetic biology: Interfacing bio‐machinery with synthetic environments
Authors: Lee Kyung‐Ho , Kim Dong‐Myung
Published: October 2013

Synthetic biology is built on the synthesis, engineering, and assembly of biological parts. Proteins are the first components considered for the construction of systems with designed biological functions because proteins carry out most of the biological functions and chemical reactions inside cells. Protein synthesis is considered to comprise the most basic levels of the hierarchical structure of synthetic biology. Cell‐free protein synthesis has emerged as a powerful technology that can potentially transform the concept of bioprocesses. With the ability to harness the synthetic power of biology without many of the constraints of cell‐based systems, cell‐free protein synthesis enables the rapid creation of protein molecules from diverse sources of genetic information. Cell‐free protein synthesis is virtually free from the intrinsic constraints of cell‐based methods and offers greater flexibility in system design and manipulability of biological synthetic machinery. Among its potential applications, cell‐free protein synthesis can be combined with various man‐made devices for rapid functional analysis of genomic sequences. This review covers recent efforts to integrate cell‐free protein synthesis with various reaction devices and analytical platforms.
Spectroscopic studies of the unfolding of a multimeric protein α‐crystallin
Authors: Chowdhury Aritra , Choudhury Aparajita , Banerjee Victor , Banerjee Rajat , Das K. P.
Published: October 2013

α‐Crystallin is a multimeric eye lens protein having molecular chaperone‐like function which is crucial for lens transparency. The stability and unfolding‐refolding properties of α‐crystallin plays important roles for its function. We undertook a multi probe based fluorescence spectroscopic approach to explore the changes in the various levels of organization of this protein at different urea concentration. Steady state fluorescence studies reveal that at 0.6M urea a compact structural intermediate is formed which has a native‐like secondary structure with enhanced surface exposure of hydrophobic groups. At 2.8M urea the tertiary interactions are largely collapsed with partial collapse of secondary and quaternary structure. The surface solvation probed by picosecond time resolved fluorescence of acrylodan labeled α‐crystallin revealed dry native‐like core of α‐crystallin at 0.6M urea compared to enhanced water penetration at 2.8M urea and extensive solvation at 6M urea. Activation energy for the subunit exchange decreased by 22 kJ mol−1 on changing urea concentration from 0 to 0.6M compared with over 75 kJ mol−1 on changing urea concentration from 0 to 2.8M. Light scattering and analytical ultracentrifugation techniques were used to determine size and oligomerization of the unfolding intermediates. The data indicated swelling but no oligomer breakdown at 0.6M urea. At 2.8M urea the oligomeric size is considerably reduced and a monomer is produced at 6M urea. The data clearly reveals that structural breakdown of α‐crystallin does not follow hierarchical sequence as tertiary structure dissolution takes place before complete oligomeric dissociation. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 549–560, 2014.
Antimicrobial peptides against Pseudomonas syringae pv. actinidiae and Erwinia amylovora: Chemical synthesis, secondary structure, efficacy, and mechanistic investigations
Authors: Cameron Alan , Zoysa Gayan Heruka De , Sarojini Vijayalekshmi
Published: October 2013

We report on structurally modified dodecapeptide amides (KYKLFKKILKFL‐NH2) and two analogs of a hexapeptide amide (WRWYCR‐NH2) with antibacterial activity against the Gram negative pathogens Pseudomonas syringae pv. actinidiae (Psa) and Erwinia amylovora (Ea). Dodecapeptide minimal inhibitory concentrations (MICs) ranged from 3.2 to 15.4 µM, with the unmodified peptide being the most potent against both pathogens. The unmodified dodecapeptide also had 32–58% α‐helicity in membrane mimetic environments (50% v/v trifluoroethanol and 30 mM SDS micelles). Structural modifications which included branching, acylation, and conjugation with 5‐nitro‐2‐furaldehyde (NFA) proved detrimental to both antimicrobial activity and α‐helicity. Scanning electron microscopy (SEM) revealed distinct morphological changes to bacterial cells treated with the different peptides, leading to blistering of the membrane and cell lysis. MICs of the hexapeptide amide were 3.9–7.7 µM against both pathogens. The hexapeptide acid did not show anti‐bacterial activity against either pathogen. However, the NFA conjugated hexapeptide acid was more active than the parent peptide or NFA alone with MICs of 1.6–3.2 µM against the pathogens. SEM analysis revealed shriveling and collapse of bacterial cells treated with the hexapeptide, whereas shortening and compactness on exposure to streptomycin. A colorimetric assay demonstrated that the dodecapeptides were likely to act by targeting the bacterial membrane, whereas the hexapeptides, streptomycin, and NFA were not, thereby supporting the morphological changes observed during SEM. To the best of our knowledge, this appears to be the first report of antimicrobial peptide activity against Psa, a pathogen that is currently devastating the kiwifruit industry internationally. © 2013 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 102: 88–96, 2014.
Novel thermo‐responsive fucose binding ligands for glycoprotein purification by affinity precipitation
Authors: Arnold Lindsay , Chen Rachel
Published: October 2013

Novel thermo‐responsive affinity sugar binders were developed by fusing a bacterial fucose lectin with a thermo‐responsive polypeptide. These designer affinity ligand fusions were produced using an Escherichia coli system capable of extracellular secretion of recombinant proteins and were isolated with a high recovery yield (95%) directly from growth medium by Inverse Temperature Cycling (ITC). With horse radish peroxidase (HRP) as a model protein, we demonstrate here that the designer thermo‐responsive ligands are capable of interacting with glycans on a glycoprotein, a property that was used to develop a novel affinity precipitation method for glycoprotein purification. The method, requiring only simple process steps, affords full recovery of a target glycoprotein, and is effective at a target glycoprotein concentration as low as 1.4 pM in the presence of large amounts of contaminants. By developing other sugar binders in the similar fashion, the method should be highly useful for glycoprotein purification and detection. Biotechnol. Bioeng. 2014;111: 413–417. © 2013 Wiley Periodicals, Inc.
Fluorogen‐activating‐proteins as universal affinity biosensors for immunodetection
Authors: Gallo Eugenio , Vasilev Kalin V. , Jarvik Jonathan
Published: October 2013

Fluorogen‐activating‐proteins (FAPs) are a novel platform of fluorescence biosensors utilized for protein discovery. The technology currently demands molecular manipulation methods that limit its application and adaptability. Here, we highlight an alternative approach based on universal affinity reagents for protein detection. The affinity reagents were engineered as bi‐partite fusion proteins, where the specificity moiety is derived from IgG‐binding proteins—Protein A or Protein G—and the signaling element is a FAP. In this manner, primary antibodies provide the antigenic selectivity against a desired protein in biological samples, while FAP affinity reagents target the constant region (Fc) of antibodies and provide the biosensor component of detection. Fluorescence results using various techniques indicate minimal background and high target specificity for exogenous and endogenous proteins in mammalian cells. Additionally, FAP‐based affinity reagents provide enhanced properties of detection previously absent using conventional affinity systems. Distinct features explored in this report include: (1) unfixed signal wavelengths (excitation and emission) determined by the particular fluorogen chosen, (2) real‐time user controlled fluorescence on‐set and off‐set, (3) signal wavelength substitution while performing live analysis, and (4) enhanced resistance to photobleaching. Biotechnol. Bioeng. 2014;111: 475–484. © 2013 Wiley Periodicals, Inc.
Factors influencing the electrokinetic injection of oligonucleotides in capillary gel electrophoresis when using laser‐induced fluorescence detection
Authors: Chen Buyun , Chen Guanhua , Bartlett Michael G.
Published: October 2013

Capillary gel electrophoresis (CGE) is a powerful tool for the analysis of oligonucleotides owing to its extraordinary resolving power. However, the only feasible injection mode for CGE, electrokinetic injection, can cause bias of the injected amount and thus reproducibility issues for CGE methods. Although the source of the bias in electrokinetic injection for analysis of small molecules by capillary zone electrophoresis has long been identified, there are very few studies on electrokinetic injection issues for biological molecules analyzed by CGE. In this study, we report three issues related to electrokinetic injection for oligonucleotides. First, the relationship between the injection amount and the sample solution resistance is not always linear for oligonucleotides, as has been observed for small molecules. Second, the injecting water prior to an oligonucleotide sample dramatically improves the reproducibility of both the injected amount and resolution through a ‘stacking‐like’ mechanism. Third, optimizing the gel concentration dramatically increases the amount of oligonucleotide that is injected into the column. Copyright © 2013 John Wiley & Sons, Ltd.
The effectiveness of borneol on pharmacokinetics changes of four ginsenosides in Shexiang Baoxin Pill in vivo
Authors: Jiang Peng , Fu Peng , Xiang Li , Wang Shuping , Liu Xiaojun , Yang Ling , Tao Jianfei , Chen Zhongliang , Zhan Changsen , Huang Ximing , Liu Runhui , Zhang Weidong
Published: October 2013

Shexiang Baoxin Pill (SBP) is a traditional Chinese medicine, widely used for cardiovascular diseases in the clinic. Ginsenosides are important effective components in SBP, but their pharmacokinetic characteristics are still not known. In this paper, we studied the pharmacokinetics of ginsenoside Rb1, Rc, Re and Rg1 in SBP and investigated the effect of borneol on the pharmacokinetic characteristic of ginsenosides based on an Agilent G6410A triple quadrupole LC/MS system. Results showed that the pharmacokinetic parameters of ginsenoside Rb1, Rc, Re and Rg1 in rat plasma after oral administration of SBP are significantly different with oral administration of SBP without Borneolum Syntheticum. Plasma pharmacokinetic profiles after oral administration of ginsenoside Rb1, Rc, Re, Rg1 and co‐administration with borneol at three different ratios (10:1, 1:1 and 1:10 ginsenoside vs borneol, w/w) were also determined. It was demonstrated that borneol can elevate the plasma concentration of ginsenosides after co‐admininstration. Copyright © 2013 John Wiley & Sons, Ltd.
Solvent bar microextraction combined with high‐performance liquid chromatography for preconcentration and determination of pramipexole in biological samples
Authors: Ghasemi Ensieh , Kheradmand Salim , Ghorban Dadrass Orkideh
Published: October 2013

A simple, rapid and sensitive analytical method for preconcentration and determination of pramipexole in different biological samples has been developed using solvent bar microextraction (SBME) combined with HPLC‐UV. The target drugs were extracted from 10 mL of basic aqueous sample solution into an organic extracting solvent located inside the pores of a polypropylene hollow fiber, then back‐extracted into an acidified aqueous solution in the lumen of the hollow fiber. In order to obtain high extraction efficiency, the effect of different variables on the extraction efficiency was studied simultaneously using an experimental design. The experimental parameters of SBME were optimized using a Box–Behnken design after a Plackett–Burman screening design. Under the optimized conditions, an enrichment factor up to 96 was achieved and the relative standard deviation of the method was 4.64% (n = 5). The linear range was 0.05–2000 µg/L with a correlation coefficient (r) of 0.987. Finally, the applicability of the proposed method was evaluated by extraction and determination of pramipexole in plasma and urine samples. The results indicated that SBME method has excellent clean‐up and high preconcentration factor and can serve as a simple and sensitive method for analysis of pramipexole in biological samples. Copyright © 2013 John Wiley & Sons, Ltd.
Saccharification of biomass using whole solid‐state fermentation medium to avoid additional separation steps
Authors: Pirota Rosangela D. P. B. , Baleeiro Flávio C. F. , Farinas Cristiane S.
Published: October 2013

The enzymatic hydrolysis of steam‐exploded sugarcane bagasse (SESB) was investigated using enzymatic extracts (EE) and whole fermentation media (WM), produced in‐house, from Aspergillus niger 3T5B8 and Trichoderma reesei Rut‐C30 cultivated on wheat bran under solid‐state fermentation (SSF). A detailed and quantitative comparison of the different hydrolysis conditions tested was carried out using the Chrastil approach for modeling enzymatic reactions by fitting the experimental data of total reducing sugar (TRS) released according to hydrolysis time. Conversion of SESB using A. niger enzymatic complex were up to 3.2‐fold higher (in terms of TRS) than T. reesei at similar enzyme loadings, which could be correlated to the higher β‐glucosidase levels (up to 35‐fold higher) of A. niger enzymatic complex. Conversion yields after 72 h exceeded 40% in terms of TRS when the WM was supplemented with a low dosage of a commercial enzyme preparation. When the combination of WM (from either T. reesei or A. niger) and commercial cellulase was used, the dosage of the commercial enzyme could be reduced by half, while still providing a hydrolysis that was up to 36% more efficient. Furthermore, SESB hydrolysis using either EE or WM resulted in similar yields, indicating that the enzyme extraction/filtration steps could be eliminated from the overall process. This procedure is highly advantageous in terms of reduced enzyme and process costs, and also avoids the generation of unnecessary effluent streams. Thus, the enzymatic conversion of SESB using the WM from SSF is cost‐effective and compatible with the biorefinery concept. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1430–1440, 2013
Why Do Members of Disadvantaged Groups Strike Back at Perceived Negativity Towards the In‐group?
Authors: Owuamalam Chuma , Issmer Christian , Zagefka Hanna , Klaßen Matthias , Wagner Ulrich
Published: October 2013

Against the background of riots in communities across London in 2011, this paper examines the implications of negative meta‐stereotypes on stigmatized group members' reactions towards members of privileged out‐groups within their communities. We hypothesized that concerns over negative opinions that the dominant out‐group is expected to hold of the in‐group (i.e. meta‐stereotypes) would be negatively associated with group members' perceptions of societal fairness and that this relationship would be mediated by members' recall of personal experiences with discrimination. We further hypothesized that views about societal fairness that are challenged in this way would lower an inclination to express discontent with the status quo via normative means while at the same time, increase nonnormative expressions. Results from two surveys (study 1, N = 50; study 2, N = 132) provided support for these hypotheses and are discussed in terms of their meaning for community relations. Copyright © 2013 John Wiley & Sons, Ltd.
Retracted: 1,3,5‐Trihydroxy‐13,13‐dimethyl‐2H‐pyran [7,6‐b] xanthone directly targets heat shock protein 27 in hepatocellular carcinoma
Authors: Fu Wei‐ming , Wang Wei‐mao , Wang Hua , Zhu Xiao , Liang Yan , Kung Hsiang‐fu , Zhang Jin‐fang
Published: October 2013

We previously showed that the small molecule 1,3,5‐trihydroxy‐13,13‐dimethyl‐2H‐pyran [7,6‐b] xanthone (TDP) induces apoptosis in hepatocellular carcinoma (HCC) by suppressing Hsp27 expression, although the mechanism is not fully understood. To investigate the functional association between TDP and Hsp27 protein in HCC, recombinant Hsp27 protein was incubated with TDP at room temperature, and assayed by mass spectrum (MS) and natural electrophoresis. TDP effectively stimulated Hsp27 to form aggregates ex vitro, leading to suppression of its chaperone activity. The aggregates were degraded by the ubiquitin–proteasome (UPS) pathway. TDP directly interacted with Asp17 and Phe55 in chain C of Hsp27 on the basis of bioinformatic prediction. In conclusion, Hsp27 is a direct target of TDP in its anti‐cancer activity, which provides strong support for a clinical application.
Rare complication of ventricular septal defect in three patients following transcatheter aortic valve replacement
Authors: Patel Yogesh , Vassileva Christina , Mishkel Gregory
Published: October 2013

Transcatheter aortic valve replacement (TAVR) is a highly‐effective but technically challenging procedure. Despite improvement in device technology and operator techniques, complications are common and previously unknown procedural‐related complications continue to arise. In this report, we present a case series of three patients with acquired perimembranous ventricular septal defects following transfemoral TAVR with an Edwards SAPIEN prosthesis. © 2013 Wiley Periodicals, Inc.
Flow Patterns in Mini‐Hydrocyclones with Different Vortex Finder Depths
Authors: He F. , Zhang Y. , Wang J. , Yang Q. , Wang H. , Tan Y.
Published: October 2013

Two‐phase flow patterns in a mini‐hydrocyclone with different insertion depths of the vortex finder were measured by a phase Doppler particle analyzer. The distributions of velocity, concentration, root‐mean‐square velocity, and average diameter of particles were evaluated. A deeper insertion of the vortex finder led to smaller tangential velocity at the cross section near the column cone interface. When the vortex finder insertion depth did not reach the column cone interface, the vortex finder was inserted deeper and the line of zero velocity value migrated more distinctly inward. When the vortex finder insertion depth reached or exceeded the column cone interface, strong turbulence occurred near the vortex finder. The distributions of the axial velocities of particles and root‐mean‐square velocities indicated that circulation flow existed at the bottom part of the mini‐hydrocyclone.
Effect of Carbon Dioxide Chemical Absorption on Bubble Diameter and Interfacial Area
Authors: López A. B. , Gómez‐Díaz D. , La Rubia M. D. , Navaza J. M.
Published: October 2013

The influence of a gas‐liquid chemical reaction on the interfacial area produced in a contactor is analyzed. Two different amines were used to capture carbon dioxide by chemical absorption. The effects of the operation time, the amine used, the concentration interval, and the gas flow rate on typical hydrodynamic parameters used in bubble columns such as the gas holdup and the Sauter mean diameter were investigated. These parameters were used to determine the interfacial area value. Significant influences on the gas‐liquid interfacial area were detected, mainly caused by the reaction rate intensity, the physicochemical properties of the liquid phase, and the gas flow rate fed to the contactor.
2,4,6‐Triarylphosphinines versus 2,4,6‐Triarylpyridines: An Investigation of the Differences in Reactivity between Structurally Related Aromatic Phosphorus and Nitrogen Heterocycles
Authors: Weemers Jarno J. M. , Wiecko Jelena , Pidko Evgeny A. , Weber Manuela , Lutz Martin , Müller Christian
Published: October 2013

The novel atropisomeric pyridine derivative rac‐10 has been synthesized and structurally characterized. In contrast to its phosphorus analogue 3, axially chiral 10 has a considerably lower rotational barrier as estimated by DFT calculations. However, the presence of the two enantiomers could be confirmed by means of chiral analytical HPLC analysis and by protonation experiments with a chiral acid. Compound rac‐10 could be further dehydrogenated by treatment with DDQ to the benzo(h)quinoline derivative rac‐12. This conversion failed for the phosphorus analogue rac‐3. Interestingly, although 2,4,6‐triarylphosphinines undergo facile CH activation with [Cp*IrCl2]2 in the presence of NaOAc, this reaction does not proceed with the corresponding pyridine derivatives. On the other hand, the latter ones can be selectively ortho‐metalated with Pd(OAc)2, leading to acetate‐bridged dimeric species, which could be unambiguously confirmed by means of X‐ray crystal structure analysis. The treatment of phosphinines with Pd(OAc)2 led instead to the formation of the unusual cofacial oxidative coupling products 16 and 17, which consist of a phosphorus‐containing cage structure.
The N‐Terminal Nonapeptide of Cephaibols A and C: A Naturally Occurring Example of Mismatched Helical Screw‐Sense Control
Authors: Orcel Ugo , De Poli Matteo , De Zotti Marta , Clayden Jonathan
Published: October 2013

The N‐terminal nonapeptide domain of the fungal nonribosomal peptide antibiotics cephaibol A and cephaibol C (AcPheAib4LeuIvaGly‐ Aib) is reported to adopt a right‐handed helical conformation in the crystalline state. However, this conformation is at odds with the left‐handed helicity observed in solution in related synthetic oligomers capped with Ac‐L‐PheAib4 fragments. We report the synthesis of four diastereoisomers of the cephaibol N‐terminal nonapeptide, and show by NMR and CD spectroscopy that the peptide containing the chiral amino acids Phe and Leu in the naturally occurring relative configuration exists in solution as an interconverting mixture of helical screw‐sense conformers. In contrast, the nonapeptide containing the unnatural relative configuration at Phe and Leu adopts a single, stable helical screw‐sense, which is left handed when the N‐terminal Phe residue is L and right‐handed when the N‐terminal Phe residue is D.
Stereoselective Synthesis of (3R)‐3‐Alkyl‐4,1‐Benzoxazepine‐2,5‐Diones
Authors: Nisar Bushra , Raza Abdul Rauf , Black David Stc. , Kumar Naresh , Tahir Muhammad Nawaz
Published: October 2013

Novel 3‐alkyl‐4,1‐benzoxazepine‐2,5‐diones were synthesized in good ee exploiting the chiral pool methodology, an economical way of asymmetric synthesis. Various anthranilic acids are coupled with different α‐haloacids to afford N‐acylated anthranilic acid intermediates which undergo cyclization to (3R)‐3‐alkyl‐4,1‐benzoxazepines‐2,5‐diones. Chirality 25:865–870, 2013. © 2013 Wiley Periodicals, Inc.
Recovery and Enantioseparation of Chiral Anesthetic Gases with Modified Porous Glasses
Authors: Munkelt Thomas , Küster Christian , Hamel Christof , Enke Dirk , Seidel‐Morgenstern Andreas , Seidel‐Morgenstern Andreas
Published: October 2013

Poröses Glas ist aufgrund seiner chemischen und physikalischen Eigenschaften sowie der Möglichkeit von gezielten Oberflächenmodifikationen vielfältig einsetzbar. In dieser Arbeit wird die Synthese und Optimierung von porösen Glaskugeln zur Rückgewinnung und Enantiomerentrennung chiraler Anästhetika beschrieben. Neben der Charakterisierung mittels Stickstoffsorption und Quecksilberintrusion wird das Retentionsverhalten von Desfluran auf nativen Trägern sowie nach Immobilisierung eines chiralen Selektors chromatographisch untersucht.
Metal Organic Frameworks for Natural Gas Storage in Vehicles
Authors: Arnold Lena , Averlant Gauthier , Marx Stefan , Weickert Mathias , Müller Ulrich , Mertel Jonathan , Horch Carsten , Peksa Mikulas , Stallmach Frank
Published: October 2013

With the increasing demand for alternative fuels the storage of natural gas (NG) in adsorbents like metal organic frameworks (MOFs) will become more important. In order to use MOFs as storage media in fuel delivery systems, the optimization of mass and energy transfer of the system is crucial. For rapid NG filling of a tank, molecules need to reach the adsorption sites within a reasonable time while the heat of adsorption should be dissipated to the environment. In this article, mass transfer in shaped bodies of MOFs was determined by permeability measurements and pulsed field gradient (PFG) NMR spectroscopy. The heat dissipation was also experimentally measured and both data sets were used to set up a theoretical density function theory model to predict the behavior of MOFs for NG storage.
Controlling Morphology of Active Layer by Tuning Coplanarity of the Centrality in Acceptor‐Donor‐Acceptor Small Molecules for Photovoltaic Application
Authors: Zhang Pan , Li Chao , Zhao Yue , Li Yaowen , Tu Yingfeng
Published: October 2013

A series of acceptor‐donor‐acceptor alternative small molecules were synthesized containing electron‐donating central building moieties of phenothiazine, 2,7‐carbazole and thieno[3,4‐b]thiophene and electron‐accepting moieties of tetrazine on both sides. The various conformations of the central blocks, with the coplanarity in an order of phenothiazine<2,7‐carbazole<thieno[3,4‐b]thiophene, have an obvious influence on the optical, electrochemical property and the crystallinity of small molecule. In addition, the blend films between small molecule and (6,6)‐phenyl‐C61‐butyric acid methyl ester offered signi?cantly various morphologies, changing from uniform surface to interpenetrated networks. As a result, the bulk heterojunction photovoltaic devices based on the three small molecules provided varied performance, and the highest coplanar molecule based device exhibited the best photovoltaic performance.
Dithieno[a,e]pentalene Based Conjugated Polymers: Synthesis and Characterization
Authors: Hu Chao , Zhang Qing
Published: October 2013

The concept of introducing π‐conjugated but anti‐aromatic repeating units into conjugated polymers has been explored. The thermal stability, optical and electrochemical properties of dithieno[a,e]pentalenes (DTP) based polymers have been studied. The effect of introducing electron withdrawing repeating units into DTP based polymer on the physical properties of polymer has also been investigated. The new polymers showed broad absorption in visible and near‐infrared region.
„A German Formula“ – Rezepte für Geheimtinten aus den Archiven der CIA
Authors: Krahl Emanuel , Ducci Matthias
Published: October 2013

Im Jahre 2011 hob der damalige CIA‐Direktor Leon Panetta die Vertraulichkeit von Dokumenten auf, die 93 Jahre lang als amerikanisches Staatsgeheimnis eingestuft wurden. Das Konvolut enthält u. a. zahlreiche Rezepturen zur Herstellung unterschiedlicher Geheimtinten für den Einsatz im Nachrichtendienst. Der vorliegende Beitrag greift eine Auswahl der Versuchsvorschriften heraus und beleuchtet die chemischen Hintergründe. Darüber hinaus wird aufgezeigt, dass diese Materialien für den Einsatz im Chemieunterricht hervorragend geeignet sind. Abschließend wird ein Experiment beschrieben, bei dem mit Haushaltsprodukten UV‐Geheimtinte hergestellt wird.
Modeling Heavy Metal Behavior in Sustainable Drainage Systems: A Case Study
Authors: Quinn Ruth , Dussaillant J. Alejandro
Published: October 2013

A major problem of increased urbanization is the rise in pollution caused by run‐off. Among alternative management strategies, the use of sustainable drainage systems (SuDS) such as rain gardens and other bioretention facilities is becoming an increasingly attractive option to reduce these problems. However, there are few tools if any available for their design considering pollutant retention. In this paper, a dual‐permeability based model that predicts the fate of heavy metals in SuDS is presented, and applied to the design of a rain garden system for a planned roundabout in Kent, UK. Preliminary design considered an upper root zone layer with organic soil and a sandy storage sub‐layer, each 30 cm thick, for a bioretention area of 5 and 10% the size of the contributing impervious surface. Two scenarios are examined: the accumulation and movement of metals without macropores and the possibility of groundwater contamination due to preferential flow. It is shown that levels of lead can build up in the upper layers of the system, but only constitute a health hazard (surpass UK standard of 750 mg/kg) after 10 years. Simulations show that copper was successfully retained (no significant concentrations below 50 cm of rain garden soil depth). Finally, given concerns of preferential flow bypassing bioretention facilities, macropore flow was examined. Results indicated that due to site conditions it was not a threat to groundwater in the timeframe considered.
Ultrastructure of cisternal synapses on outer hair cells of the mouse cochlea
Authors: Fuchs Paul Albert , Lehar Mohamed , Hiel Hakim
Published: October 2013

C (cisternal) synapses with a near membrane postsynaptic cistern are found on motor neurons and other central neurons, where their functional role is unknown. Similarly structured cisternal synapses mediate cholinergic inhibition of cochlear hair cells via α9α10‐containing ionotropic receptors and associated calcium‐activated (SK2) potassium channels, providing the opportunity to examine the ultrastructure of genetically altered cisternal synapses. Serial section electron microscopy was used to examine efferent synapses of outer hair cells (OHCs) in mice with diminished or enhanced cholinergic inhibition. The contact area of efferent terminals, the appositional area of the postsynaptic cistern, the distance of the cistern from the plasma membrane, and the average width of the cisternal lumen were recorded. The synaptic cisterns of wild‐type OHCs were closely aligned (14‐nm separation) with the hair cell membrane and coextensive with the micrometers‐long synaptic terminals. The cisternal lumen averaged 18 nm so that the cisternal volume was approximately 30% larger than that of the cytoplasmic space between the cistern and the plasma membrane. Synaptic ultrastructure of α9L9′T knockin OHCs (acetylcholine receptor gain of function) were like those of wild‐type littermates except that cisternal volumes were significantly larger. OHCs of SK2 knockout mice had few small efferent terminals. Synaptic cisterns were present, but smaller than those of wild‐type littermates. Taken together, these data suggest that the cistern serves as a sink or buffer to isolate synaptic calcium signals. J. Comp. Neurol. 522:717–729, 2014. © 2013 Wiley Periodicals, Inc.
Derivation of aortic distensibility and pulse wave velocity by image registration with a physics‐based regularisation term
Authors: Barber David C. , Valverde Isra , Shi Yubing , Brown Alistair , Beerbaum Philipp , Rodney Hose D.
Published: October 2013

Analysis of the cardiovascular system represents a classical problem in which the solid and fluid phases interact intimately, and so is a rich field of application for state‐of‐the‐art fluid–solid interaction (FSI) analyses. In this paper, we focus on the human aorta. Solution of the full FSI problem requires knowledge of the material properties of the wall and information on vessel support. We show that variation of distensibility along the aorta can be obtained from four‐dimensional image data using image registration. If pressure data at one point in the vessel are available, these can be converted to absolute values. Alternatively, values of pulse wave velocity along the vessel can be obtained. The quality of the extracted data is improved by the incorporation into the registration of a regularisation term based on the one‐dimensional wave equation. The method has been validated using simulated data. For idealised vessels, the accuracy with which the distensibility and wave velocity can be extracted is high (1%–2%). The method is applied to six clinical datasets from patients with mild coarctation, for which it is shown that wave velocity along the aorta is relatively constant. Copyright © 2013 John Wiley & Sons, Ltd.
Structure, Stoichiometry, and Electrochemical Performance of Li2CoTi3O8 as an Anode Material for Lithium‐Ion Batteries
Authors: Wang Jie , Zhao Hailei , Shen Yongna , Du Zhihong , Chen Xiaomin , Xia Qing
Published: October 2013

Li2CoTi3O8 powder has been synthesized by a simple citric nitrate method and was evaluated as an anode material for lithium‐ion batteries. The X‐ray diffraction (XRD) Rietveld refinement and X‐ray photoelectron spectroscopy (XPS) measurements indicate the existence of Ti‐site deficiency and a mixed‐valence state of Co ions in the Li2CoTi3O8 structure. The refined site‐occupation result gave a nonstoichiometric chemical formula of Li2CoTi2.682O8, which corresponds to a theoretical specific capacity of 322 mA h g−1, which is much higher than that of the stoichiometric material (233 mA h g−1). The synthesized Li2CoTi2.682O8 material exhibits high reversible capacity (ca. 320 mA h g−1), and excellent cycling stability and rate capability. A specific capacity of about 240 and 160 mA h g−1 can be achieved at 2 and 6 A g−1, respectively, by the Li2CoTi2.682O8 material. First‐principles calculation demonstrates that Ti‐site deficiency decreases the bandgap and thus facilitates the electron conduction.
Metal Segregation in Bimetallic CoPd Carbide Carbonyl Clusters: Synthesis, Structure, Reactivity and Electrochemistry of [H6−nCo20Pd16C4(CO)48]n− (n=3–6)
Authors: Ciabatti Iacopo , Fabrizi de Biani Fabrizia , Femoni Cristina , Iapalucci Maria Carmela , Longoni Giuliano , Zacchini Stefano
Published: October 2013

Nanometric CoPd bimetallic [H6−nCo20Pd16C4(CO)48]n− (n=3–6) tetracarbide carbonyl clusters have been prepared by redox condensation of [Co6C(CO)15]2− with [PdCl2(Et2S)2]. The crystal structures of both the dihydride tetra‐anion and monohydride penta‐anion have been determined as their [NEt4]4[H2Co20Pd16C4(CO)48]⋅4 CH3COCH3 and [NMe3(CH2Ph)][NMe4]4[HCo20Pd16C4(CO)48]⋅5 CH3COCH3 salts, respectively. The two species are isostructural and their structures display a perfect segregation of the two metals. They are composed of a cubic close‐packed (ccp) Pd16 core stabilised on its surface by four {Co5C(CO)12} organometallic fragments. Their polyhydride nature has been corroborated by the study of their reactions with acids and bases, and confirmed by electrochemical studies. In addition, the reactions of [H2Co20Pd16C4(CO)48]4− with Na/naphthalene and PPh3/CO allowed the isolation of other lower nuclearity homoleptic and heteroleptic clusters, that is, [H6−nCo16Pd2C3(CO)28]n− (n=5, 6), [Co4Pd2C(CO)11(PPh3)2], [Co2Pd5C(CO)8(PPh3)5], and [Co4Pd4C2(PPh3)4(CO)10Cl]−. [H6−nCo16Pd2C3(CO)28]n− (n=5, 6) represent the first homoleptic metal–carbonyl clusters containing three interstitial carbide atoms.
Efficient identity‐based key encapsulation scheme with wildcards for email systems
Authors: Yang Yang
Published: October 2013

Identity‐based key encapsulation scheme with wildcards (WIB‐KEM) is very useful in email systems for confidential communication, as it enables the effective encryption of email to a range of users simultaneously whose identities match a certain pattern. In this paper, I propose a WIB‐KEM scheme achieving simultaneously high efficiency and security level. Our scheme achieves the low computational cost because during the decryption phase the bilinear pairing operation of decryption is constant. Moreover, the private key size shrinks as the identity depth increases. I further prove its adaptive chosen ciphertext security under decisional bilinear Diffie–Hellman assumption in standard model. The scheme not only can meet security demands but is also efficient in terms of computation and communication. Our scheme is tested on a modern station, and the experimental results demonstrate its suitability for large‐scale email systems. Copyright © 2013 John Wiley & Sons, Ltd.
A novel compressed sensing ultra‐wideband channel estimation method based on non‐convex optimization
Authors: Wang Wei‐dong , Yang Jun‐an , Zhang Chun
Published: October 2013

Due to the low power spectral density and complicated transfer propagation of ultra‐wideband (UWB) signal, it is important to estimate UWB channel accurately. But it is difficult to sample UWB signals directly due to their wider band width. However, compressed sensing (CS) theory provides a feasible way through lower sampling speed. Common CS‐UWB channel estimation methods adopt convex optimization, non‐sparse or non‐restricted form. In order to strengthen the restriction on sparsity of the reconstructed channel vector, a non‐convex optimization method is proposed in this paper to estimate UWB channel. Proposed method sets the objective function as a non‐convex optimization model using lp–norm. This model is combined as a convex function to approximate the objective function and reconstruct the UWB channel vector iteratively. Because lp–norm is closer to l0–norm than l1 and l2–norm, its restriction on sparsity of objective vector is stricter. The simulation results show that this method can enhance reconstruction performance compared with existing CS‐UWB channel estimation methods. Copyright © 2013 John Wiley & Sons, Ltd.
Common quantitative trait locus downstream of RETN gene identified by genome‐wide association study is associated with risk of type 2 diabetes mellitus in Han Chinese: a Mendelian randomization effect
Authors: Chung Chia‐Min , Lin Tsung‐Hsien , Chen Jaw‐Wen , Leu Hsin‐Bang , Yin Wei‐Hsian , Ho Hung‐Yun , Sheu Sheng‐Hsiung , Tsai Wei‐Chuan , Chen Jyh‐Hong , Lin Shing‐Jong , Pan Wen‐Harn
Published: October 2013

Objective

Plasma resistin level is a potential molecular link between obesity and diabetes. Causal role of resistin, type 2 diabetes mellitus (T2DM) and genetic variants have not been thoroughly investigated. Therefore, we conducted a genome‐wide association study (GWAS) to identify quantitative trait loci associated with resistin levels and investigated whether these variants were prospectively associated with the development of metabolic syndrome (MetS) and T2DM in an independent community‐based cohort, the CardioVascular Disease risk FACtors Two‐township Study (CVDFACTS).

Research Design and Methods

We genotyped 382 young‐onset hypertensive (YOH) subjects with Illumina HumanHap550 chips and searched for quantitative trait loci (QTLs) of resistin in the 1st stage GWAS and confirmed the finding in another 559 YOH subjects. Logistic regression was used to examine the Mendelian randomization effects between genotypes of confirmed QTLs and metabolic outcomes in 3400 subjects of CVDFACTS.

Results

Two single nucleotide polymorphisms (SNP) (rs3745367 and rs1423096) were significantly associated with resistin levels (p = 5.52 × 10−15 and p = 2.54 × 10−20) and replicated in another 559 YOH subjects (p = 1.29 × 10−3 and p = 1.13 × 10−7), respectively. The SNP rs1423096 was further associated with the levels of HDL‐C (p = 0.006), the risk of MetS (OR = 2.21, p = 0.0034) and T2DM (OR = 1.62, p = 0.0063) in the CVDFACTS. People with the haplotypes A‐G and G‐G determined by rs3745367 and rs1423096 showed a significantly increased T2DM risk (p = 0.0068 and p = 0.0035, respectively) compared with those with A‐A haplotype.

Conclusion

We have found that rs3745367 and rs1423096 on the RETN gene were significantly associated with resistin levels. However, rs1423096, downstream of RETN, seems to be associated with MetS and T2DM risk more so than rs3745367. The established genotype–disease association points to a causal association of resistin and T2DM. Copyright © 2013 John Wiley & Sons, Ltd.