bluuebunny/crossref_metadata_2025 huggingface dataset:
An integrated natural remanent magnetization acquisition model for the Matuyama‐Brunhes reversal recorded by the Chinese loess
Authors: Jin Chunsheng , Liu Qingsong , Hu Pengxiang , Jiang Zhaoxia , Li Cange , Han Peng , Yang Huihui , Liang Wentian
Published: July 2016

Geomagnetic polarity reversal boundaries are key isochronous chronological controls for the long Chinese loess sequences, and further facilitate paleoclimatic correlation between Chinese loess and marine sediments. However, owing to complexity of postdepositional remanent magnetization (pDRM) acquisition processes related to variable dust sedimentary environments on the Chinese Loess Plateau (CLP), there is a long‐standing dispute concerning the downward shift of the pDRM recorded in Chinese loess. In this study, after careful stratigraphic correlation of representative climatic tie points and the Matuyama‐Brunhes boundaries (MBB) in the Xifeng, Luochuan, and Mangshan loess sections with different pedogenic environments, the downward shift of the pDRM is semiquantitatively estimated and the acquisition model for the loess natural remanent magnetization (NRM) is discussed. The measured MB transition zone has been affected by the surficial mixing layer (SML) and remagnetization. Paleoprecipitation is suggested to be the dominant factor controlling the pDRM acquisition processes. Rainfall‐controlled leaching would restrict the efficiency of the characterized remanent magnetization carriers aligning along the ancient geomagnetic field. We conclude that the MBB in the central CLP with moderate paleoprecipitation could be considered as an isochronous chronological control after moderate upward adjustment. A convincing case can then be made to correlate L8/S8 to MIS 18/19.
Should flood regimes change in a warming climate? The role of antecedent moisture conditions
Authors: Woldemeskel Fitsum , Sharma Ashish
Published: July 2016

Assessing changes to flooding is important for designing new and redesigning existing infrastructure to withstand future climates. While there is speculation that floods are likely to intensify in the future, this question is often difficult to assess due to inadequate records on streamflow extremes. An alternate way of determining possible extreme flooding is through assessment of the two key factors that lead to the intensification of floods: the intensification of causative rainfall and changes in the wetness conditions prior to rainfall. This study assesses global changes in the antecedent wetness prior to extreme rainfall. Our results indicate a significant increase in the antecedent moisture in Australia and Africa over the last century; however, there was also a decrease in Eurasia and insignificant change in North America. Given the nature of changes found in this study, any future flood assessment for global warming conditions should take into account antecedent moisture conditions.
Fracture sealing by mineral precipitation: The role of small‐scale mineral heterogeneity
Authors: Jones Trevor A. , Detwiler Russell L.
Published: July 2016

Fractures are often leakage pathways for fluid in low‐permeability rocks that otherwise act as geologic barriers in the subsurface. Flow of fluids in chemical disequilibrium with fracture surfaces can lead to mineral precipitation and fracture sealing. To directly evaluate the role of small‐scale mineral heterogeneity on mineral precipitation, we measured CaCO3 precipitation in a transparent analog fracture that included randomly distributed small‐scale regions of CaCO3 on one of the borosilicate surfaces. Steady flow of a well‐mixed CaCl2‐NaHCO3 solution (
 = 1.44) resulted in significant mineral precipitation during the 82 day experiment. Localized mineral precipitation reduced flow within regions of the fracture, but small‐scale reaction‐site heterogeneity allowed preferential flow to persist through pathways that contained 82% less area of CaCO3 regions than the fracture‐scale average. This resulted in a significant reduction in measured precipitation rate; excluding these effects results in more than an order‐of‐magnitude underestimation of fracture sealing timescales.
Self‐Templated Synthesis of Ultrathin Nanosheets Constructed TiO2 Hollow Spheres with High Electrochemical Properties
Authors: Xie Huiqi , Hu Linfeng , Wu Feilong , Chen Min , Wu Limin
Published: July 2016

TiO2 is well‐known nanomaterials and mostly used as solid nanoparticles, and normal hollow spheres for photocatalysts or electrode materials. In this study, a novel self‐templated method is presented to successfully fabricate high‐surface‐area ultrathin nanosheets constructed TiO2 hollow spheres through the solvothermal treatment of the titanate–silicone composite particles combined with calcination. The uniquely structured hollow spheres exhibit excellent rate capability and good cycle stability even at a high current density of ≈10 C for the anode material of Li‐ion battery.
A Flexible Platform Containing Graphene Mesoporous Structure and Carbon Nanotube for Hydrogen Evolution
Authors: Zhang Rujing , Li Xiao , Zhang Li , Lin Shuyuan , Zhu Hongwei
Published: July 2016

It is of great significance to design a platform with large surface area and high electrical conductivity for poorly conductive catalyst for hydrogen evolution reaction (HER), such as molybdenum sulfide (MoSx), a promising and cost‐effective nonprecious material. Here, the design and preparation of a free‐standing and tunable graphene mesoporous structure/single‐walled carbon nanotube (GMS/SWCNT) hybrid membrane is reported. Amorphous MoSx is electrodeposited on this platform through a wet chemical process under mild temperature. For MoSx@GMS/SWCNT hybrid electrode with a low catalyst loading of 32 μg cm−2, the onset potential is near 113 mV versus reversible hydrogen electrode (RHE) and a high current density of ≈71 mA cm−2 is achieved at 250 mV versus RHE. The excellent HER performance can be attributed to the large surface area for MoSx deposition, as well as the efficient electron transport and abundant active sites on the amorphous MoSx surface. This novel catalyst is found to outperform most previously reported MoSx‐based HER catalysts. Moreover, the flexibility of the electrode facilitates its stable catalytic performance even in extremely distorted states.
Imaging and cerebrospinal fluid biomarkers in early preclinical alzheimer disease
Authors: Vlassenko Andrei G. , McCue Lena , Jasielec Mateusz S. , Su Yi , Gordon Brian A. , Xiong Chengjie , Holtzman David M. , Benzinger Tammie L. S. , Morris John C. , Fagan Anne M.
Published: July 2016

Objective

Deposition of amyloid β (Aβ)‐containing plaques as evidenced by amyloid imaging and cerebrospinal fluid (CSF) Aβ1–42 (Aβ42) is an early indicator of preclinical Alzheimer disease (AD). To better understand their relationship during the earliest preclinical stages, we investigated baseline CSF markers in cognitively normal individuals at different stages of amyloid deposition defined by longitudinal amyloid imaging with Pittsburgh compound B (PIB): (1) PIB‐negative at baseline and follow‐up (PIB−; normal), (2) PIB‐negative at baseline but PIB‐positive at follow‐up (PIB converters; early preclinical AD), and (3) PIB‐positive at baseline and follow‐up (PIB+; preclinical AD).

Methods

Cognitively normal individuals (n = 164) who had undergone baseline PIB scan and CSF collection within 1 year of each other and at least 1 additional PIB follow‐up were included. Amyloid status was defined dichotomously using an a priori mean cortical cutoff.

Results

PIB converters (n = 20) at baseline exhibited significantly lower CSF Aβ42 compared to those who remained PIB‐negative (n = 123), but higher compared to the PIB+ group (n = 21). A robust negative correlation (r = −0.879, p = 0.0001) between CSF Aβ42 and absolute (but subthreshold) PIB binding was observed during this early preclinical stage. The negative correlation was not as strong once individuals were PIB‐positive (r = −0.456, p = 0.038), and there was no correlation in the stable PIB− group (p = 0.905) or in the group (n = 10) with early symptomatic AD (p = 0.537).

Interpretation

CSF Aβ42 levels are tightly coupled with cortical amyloid load in the earliest stages of preclinical AD, and begin to decrease dramatically prior to the point when an abnormal threshold of cortical accumulation is detected with amyloid imaging. Ann Neurol 2016;80:379–387
A Nanoarchitecture Based on Silver and Copper Oxide with an Exceptional Response in the Chlorine‐Promoted Epoxidation of Ethylene
Authors: Ramirez Adrian , Hueso Jose L. , Suarez Hugo , Mallada Reyes , Ibarra Alfonso , Irusta Silvia , Santamaria Jesus
Published: July 2016

The selective oxidation of ethylene to ethylene epoxide is highly challenging as a result of competing reaction pathways leading to the deep oxidation of both ethylene and ethylene oxide. Herein we present a novel catalyst based on silver and copper oxide with an excellent response in the selective oxidation pathway towards ethylene epoxide. The catalyst is composed of different silver nanostructures dispersed on a tubular copper oxide matrix. This type of hybrid nanoarchitecture seems to facilitate the accommodation of chlorine promoters, leading to high yields at low reaction temperatures. The stability after the addition of chlorine promoters implies a substantial improvement over the industrial practice: a single pretreatment step at ambient pressure suffices in contrast with the common practice of continuously feeding organochlorinated precursors during the reaction.
Biopolymer films to control fusarium dry rot and their application to preserve potato tubers
Authors: Bilbao‐Sainz Cristina , Chiou Bor‐Sen , Valenzuela‐Medina Diana , Imam Syed H. , Vega‐Gálvez Antonio , Orts William J.
Published: July 2016

Films were cast using sodium alginate (NaAlg), high molecular weight (HMW) chitosan, and low molecular weight (LMW) chitosan as film forming biopolymers. Fludioxonil (Fl) at 1% concentration was used as fungicide. Thermal stability, mechanical, and water sorption properties of the films were examined. The effects of films on the Fusarium solani colony radial growth were evaluated in vitro and in potato tubers. Results showed that chitosan films were more thermally stable and less hydrophilic than alginate films. Addition of fluodioxonil to the films significantly reduced the film strength and increased the elongation at break as well as the film stiffness. In vitro studies showed that when fludioxonil was added to the formulation, NaAlg and Chitosan‐LMW films had significantly higher antifungal activity (Fungistatic index = 56%) than Chitosan‐HMW films (Fungistatic index = 50%). In vivo studies showed that Chitosan‐LMW‐1%Fl films delay the mycelial growth of F. solani in tubers kept at 25 °C for 2 weeks. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44017.
A dipeptide‐based superhydrogel: Removal of toxic dyes and heavy metal ions from waste water
Authors: Nandi Nibedita , Baral Abhishek , Basu Kingshuk , Roy Subhasish , Banerjee Arindam
Published: July 2016

A short peptide‐based molecule has been found to form a strong hydrogel at phosphate buffer solution of pH 7.46. The hydrogel has been characterized thoroughly using various techniques including field emission scanning electron microscopy (FE‐SEM), wide angle powder X‐ray diffraction (PXRD), and rheological analysis. It has been observed from FE‐SEM images that entangled nanofiber network is responsible for gelation. Rheological investigation demonstrates that the self‐assembly of this synthetic dipeptide results in the formation of mechanically strong hydrogel with storage modulus (G′) around 104 Pa. This gel has been used for removing both cationic and anionic toxic organic dyes (Brilliant Blue, Congo red, Malachite Green, Rhodamine B) and metal ions (Co2+ and Ni2+) from waste water. Moreover, only a small amount of the gelator is required (less than 1 mg/mL) for preparation of this superhydrogel and even this hydrogel can be reused three times for dye/metal ion absorption. This signifies the importance of the hydrogel towards waste water management.
Prediction of survival of diffuse large B‐cell lymphoma patients via the expression of three inflammatory genes
Authors: Zhao Shuangtao , Bai Nan , Cui Jianlin , Xiang Rong , Li Na
Published: July 2016

Currently, several gene‐expression signatures that were used to predict survival of diffuse large B‐cell lymphoma (DLBCL) patients, showed a restriction on the practical work for lack of convenient operation. In this study, we screened inflammatory genes whose expression correlated with survival of DLBCL and established a predictive model including IL6, IL1A and CSF3 through multivariate Cox regression based on the expression of these three genes. We validated the model at protein level in our clinical serum cohort composed of 101 patients of DLBCL and 50 healthy controls and 534 DLBCL patients at mRNA level from three independent Gene Expression Omnibus (GEO) data sets. We found our model to be independent of the International Prognostic Index (IPI), moreover, it can augment the predictive power of IPI. In summary, our three‐gene model is sufficient to predict survival of DLBCL patients via measuring the concentration of three inflammatory cytokines in peripheral blood.
Antiplatelet therapy and outcome in patients undergoing surgery following coronary stenting: Results of the surgery after stenting registry
Authors: Rossini Roberta , Angiolillo Dominick J. , Musumeci Giuseppe , Capodanno Davide , Lettino Maddalena , Trabattoni Daniela , Pilleri Annarita , Calabria Paolo , Colombo Paola , Bernabò Paola , Ferlini Marco , Ferri Marco , Tarantini Giuseppe , De Servi Stefano , Savonitto Stefano
Published: July 2016

Objectives

The aim of the present study was to define the feasibility and clinical impact of complying with national consensus recommendations on perioperative management of antiplatelet therapy in patients with coronary stents undergoing cardiac and noncardiac surgery.

Background

There are limited evidence‐based recommendations on the perioperative management of antiplatelet therapy in stented patients undergoing surgery.

Methods

The recommendations provided by the national consensus document were applied in a multicenter, prospective registry of consecutive patients with prior coronary stenting undergoing any type of surgery at 19 hospitals in Italy. The primary end‐point was in‐hospital net adverse clinical events (NACE) represented by the composite of all‐cause death, myocardial infarction, probable/definite stent thrombosis and Bleeding Academic Research Consortium (BARC) grade ≥3 bleeding. Patients were followed for 30 days.

Results

A total of 1,082 patients were enrolled. Adherence to consensus recommendations occurred in 85% of the cases. Perioperative aspirin and dual antiplatelet therapy were maintained in 69.7 and 10.5% of the cases, respectively. In‐hospital NACE rate was 12.7%, being significantly higher in patients undergoing cardiac surgery (36.3% vs. 7.3%, P < 0.01), mainly due to BARC 3 bleeding events (32.3%). At 30 days, MACE rates were similar (3.5% vs. 3.5%, P = NS) in patients undergoing cardiac and noncardiac surgery, whereas BARC ≥3 bleeding events were significantly higher with cardiac surgery (36.3% vs. 5.6%, P < 0.01).

Conclusions

The results of this registry demonstrate the safety and feasibility of applying a national consensus document on the perioperative management of antiplatelet therapy in stented patients undergoing surgery. © 2016 Wiley Periodicals, Inc.
Ablation or surgery for medically refractory HCM. Updating an imperfect dataset
Authors: Bader Yousef , Kimmelstiel Carey
Published: July 2016

Key Points

Retrospective comparison of alcohol septal ablation with surgical myectomy suggests that although there is a greater reduction in LVOT gradient with surgical myectomy, symptom relief and survival are similar between the two treatment strategies.

In patients who don't have an anatomic indication for surgical myectomy, alcohol septal ablation appears to be a safe and effective alternative.

Patients with medication‐refractory HOCM require a multi‐disciplinary assessment, which is best performed at specialized treatment centers, to assess which therapy is best suited to treat them.
Molybdenum Imido Alkylidene N‐Heterocyclic Carbene Complexes: Structure–Productivity Correlations and Mechanistic Insights
Authors: Buchmeiser Michael R. , Sen Suman , Lienert Christina , Widmann Laura , Schowner Roman , Herz Katharina , Hauser Philipp , Frey Wolfgang , Wang Dongren
Published: July 2016

The syntheses and single‐crystal X‐ray structures of a series of Mo–imido alkylidene N‐heterocyclic carbene (NHC) complexes (1–15) and of the first complexes containing bidentate NHC‐phenolate ligands (16–18) are reported. Mo(N‐2,6‐Me2‐C6H3)((1‐R‐phenethyl)‐3‐mesitylimidazolidin‐2‐ylidene)(CHR)(OTf)2 (R=CMe2Ph, 1) is the first enantiomerically pure Mo–imido alkylidene NHC catalyst. With [Mo(N‐2,6‐Me2‐C6H3)(IMes)(CHR)(CH3CN)(OTf)(CH3CN)+ B(ArF)4−] (7), turnover numbers up to 545 000 were achieved in the homometathesis (HM) of 1‐octene and 1‐nonene (≤95 % E). With 7 and 1‐nonene, a turnover frequency (TOF4 min) of 8860 min−1 was determined. Productivity and E/Z‐selectivity were correlated with catalyst structure. For 1, Mo(N‐3,5‐Me2‐C6H3)(IMesH2)(CHR)(OTf)2 (9) and Mo(N‐3,5‐Me2‐C6H3)(IMes)(CHR)(OTf)2 (10), productivity was correlated with the coalescence temperature of the two triflates, determined by variable‐temperature 19F NMR spectroscopy. The square‐planar conformer is postulated to be the most relevant for the catalyst activation.
Star‐Shaped Conjugated Molecules with Oxa‐ or Thiadiazole Bithiophene Side Arms
Authors: Kotwica Kamil , Kostyuchenko Anastasia S. , Data Przemyslaw , Marszalek Tomasz , Skorka Lukasz , Jaroch Tomasz , Kacka Sylwia , Zagorska Malgorzata , Nowakowski Robert , Monkman Andrew P. , Fisyuk Alexander S. , Pisula Wojciech , Pron Adam
Published: July 2016

Star‐shaped conjugated molecules, consisting of a benzene central unit symmetrically trisubstituted with either oxa‐ or thiadiazole bithiophene groups, were synthesized as promising molecules and building blocks for application in (opto)electronics and electrochromic devices. Their optical (Eg(opt)) as well as electrochemical (Eg(electro)) band gaps depended on the type of the side arm and the number of solubilizing alkyl substituents. Oxadiazole derivatives showed Eg(opt) slightly below 3 eV and by 0.2 eV larger than those determined for thiadiazole‐based compounds. The presence of alkyl substituents in the arms additionally lowered the band gap. The obtained compounds were efficient electroluminophores in guest/host‐type light‐emitting diodes. They also showed a strong tendency to self‐organize in monolayers deposited on graphite, as evidenced by scanning tunneling microscopy. The structural studies by X‐ray scattering revealed the formation of supramolecular columnar stacks in which the molecules were organized. Differences in macroscopic alignment in the specimen indicated variations in the self‐assembly mechanism between the molecules. The compounds as trifunctional monomers were electrochemically polymerized to yield the corresponding polymer network. As shown by UV/Vis‐NIR spectroelectrochemical studies, these networks exhibited reversible electrochromic behavior both in the oxidation and in the reduction modes.
A Multifunctional Surface That Simultaneously Balances Hydrophilic Enzyme Catalysis and Hydrophobic Water Repellency
Authors: Lawton Timothy J. , Uzarski Joshua R. , Filocamo Shaun F.
Published: July 2016

The compatibility of multiple functions at a single interface is difficult to achieve, but is even more challenging when the functions directly counteract one another. This study provides insight into the creation of a simultaneously multifunctional surface formed by balancing two orthogonal functions; water repellency and enzyme catalysis. A partially fluorinated thiol is used to impart bulk hydrophobicity on the surface, and an N‐hydroxysuccinimide ester‐terminated thiol provides a specific anchoring sites for the covalent enzyme attachment. Different ratios of the two thiols are mixed together to form amphiphilic self‐assembled monolayers, which are characterized with polarization‐modulation infrared reflection–absorption spectroscopy and contact angle goniometry. The enzyme activity is measured by a fluorescence assay. With the results collected here, specific surface compositions are identified at which the orthogonal functions of water repellency and enzyme catalysis are balanced and exist simultaneously. An understanding of how to effectively balance orthogonal functions at surfaces can be extended to a number of higher‐scale applications.
Uranium–Carbene–Imido Metalla‐Allenes: Ancillary‐Ligand‐Controlled cis‐/trans‐Isomerisation and Assessment of trans Influence in the R2C=UIV=NR′ Unit (R=Ph2PNSiMe3; R′=CPh3)
Authors: Lu Erli , Cooper Oliver J. , Tuna Floriana , Wooles Ashley J. , Kaltsoyannis Nikolas , Liddle Stephen T.
Published: July 2016

Uranium(IV)–carbene–imido complexes [U(BIPMTMS)(NCPh3)(κ2‐N,N′‐BIPY)] (2; BIPMTMS=C(PPh2NSiMe3)2; BIPY=2,2‐bipyridine) and [U(BIPMTMS)(NCPh3)(DMAP)2] (3; DMAP=4‐dimethylamino‐pyridine) that contain unprecedented, discrete R2C=U=NR′ units are reported. These complexes complete the family of E=U=E (E=CR2, NR, O) metalla‐allenes with feasible first‐row hetero‐element combinations. Intriguingly, 2 and 3 contain cis‐ and trans‐C=U=N units, respectively, representing rare examples of controllable cis/trans isomerisation in f‐block chemistry. This work reveals a clear‐cut example of the trans influence in a mid‐valent uranium system, and thus a strong preference for the cis isomer, which is computed in a co‐ligand‐free truncated model—to isolate the electronic trans influence from steric contributions—to be more stable than the trans isomer by approximately 12 kJ mol−1 with an isomerisation barrier of approximately 14 kJ mol−1.
Conducting Graphene Decorated Li3V2(PO4)3/C for Lithium‐Ion Battery Cathode with Superior Rate Capability and Cycling Stability
Authors: Zhou Pan , He Dawei
Published: July 2016

In this study, core‐shell structured Li3V2(PO4)3/C wrapped in graphene nanosheets has been successfully prepared. The reduction of graphene oxide and the synthesis of Li3V2(PO4)3/C are carried out simultaneously using a chemical route followed by a solid‐state reaction. The effects of conducting graphene are studied by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectra and electrochemical measurements. The results reveal that the graphene sheets not only form a compact and uniform coating layer throughout the Li3V2(PO4)3/C, but also stretch out and cross‐link into a conducting network around the Li3V2(PO4)3/C particles. Thus, the graphene decorated Li3V2(PO4)3/C electrode exhibits superior high‐rate capability and long‐cycle stability. It delivers a reversible discharge capacity of 178.2 mAh·g−1 after 60 cycles at a current density of 0.1 C, and the rate performances of 176, 169.3, 156.1 and 135.7 mAh·g−1 at 1, 2, 5 and 10 C, respectively. The superior electrochemical properties make the graphene decorated Li3V2(PO4)3/C composite a promising cathode material for high‐performance lithium‐ion battery.
Synergistic Enhancement of Electrocatalytic Activity toward Oxygen Reduction Reaction in Alkaline Electrolytes with Pentabasic (Fe, B, N, S, P)‐Doped Reduced Graphene Oxide
Authors: Chen Wei , Sin Munil , Wei Ping‐Jie , Zhang Qian‐Ling , Liu Jin‐Gang
Published: July 2016

As alternatives to Pt‐based electrocatalysts, the development of nonprecious metal catalysts with high performance in the cathodic oxygen reduction reaction (ORR) is highly desirable for widespread use in fuel cells. Here we report a simple approach for preparing pentabasic (Fe, B, N, S, P)‐doped reduced graphene oxide (rGO) via a two‐step doping method of adding boric acid and ferric chloride to ternary (N, S, P)‐doped rGO (NSPG). Electrochemical investigation of the composites for the ORR revealed that simultaneously doping appropriate amounts of Fe and B into the NSPG produced a synergistic effect that endowed the prepared catalyst with both a positively shifted ORR half‐wave potential and high selectivity for the 4e− reduction of O2. The optimized Fe2B‐NSPG catalyst approached a 4e− process for the ORR with a half‐wave potential (E1/2=0.90 V vs. RHE) even 30 mV higher than that of the commercial Pt/C catalyst in alkaline solution. Furthermore, relative to the Pt/C catalyst, the Fe2B‐NSPG demonstrated superior stability and excellent tolerance of the methanol cross‐over effect. This simple method afforded pentabasic (Fe, B, N, S, P)‐doped rGO as a promising nonprecious metal catalyst used for alkaline fuel cells.
Synthesis of Unsymmetrical 1,3‐Diynes via Pd/Cu‐Catalyzed Cross‐Coupling of Terminal Alkynes at Room Temperature
Authors: Liu Yashuai , Liu Ping , Gu Ningning , Xie Jianwei , Liu Yan , Dai Bin
Published: July 2016

A facile and practical synthetic route of unsymmetrical 1,3‐diynes via the PdCl/CuI catalyzed oxidative coupling of two different terminal alkynes has been developed by using 3‐(diphenylphosphino)propanoic acid as a ligand in the presence of oxygen. This system is suitable for not only aromatic alkynes but also heteroaromatic and aliphatic alkynes which were transformed into the corresponding unsymmetrical 1,3‐diynes in moderate to good yields at room temperature. Moreover, the unsymmetrical 1,3‐diynes were also obtained on a multi‐gram scale. Mechanistic studies suggest that oxygen plays a key role in the catalytic cycles.
Photoelectrochemical Behavior of Sn‐Doped α‐Fe2O3 Photoanode with Different Reducer
Authors: Cai Jiajia , Liu Yinglei , Li Song , Gao Meiqi , Qin Gaowu
Published: July 2016

Hematite has been considered as one of the most promising photoanode candidates for solar water‐splitting. However, its photoelectrochemical (PEC) efficiency is largely constrained by its sluggish oxygen evolution reaction. In this work, the photoelectrochemical performance of hematite was investigated in electrolytes containing different sacrificial agent. The photocurrent densities, onset potential, charge transfer resistance, Helmholtz capacitance at semiconductor liquid junctions (SCLJs), and their correlations were systematically studied. It was found that the onset potential is around the CH peak potential and is related to the photovoltage. The surface states pinning the Fermi levels of the hematite photoanode are related to the adsorbed water molecules regardless of the sacrificial agents in the electrolyte.
Porous CoF2 Spheres Synthesized by a One‐Pot Solvothermal Method as High Capacity Cathode Materials for Lithium‐Ion Batteries
Authors: Guan Qun , Cheng Jianli , Li Xiaodong , Ni Wei , Wang Bin
Published: July 2016

Up to now, there are rare reports of CoF2 spheres used as high capacity cathode materials. Herein, porous CoF2 spheres were synthesized and studied as cathode materials for LIBs. The porous CoF2 spheres were synthesized by a facile one‐pot solvothermal method using a safe and inexpensive ammonium fluoride as the fluorine sources. The nature of the synthesis can avoid using corrosive fluorine sources and additional high‐temperature thermal treatment. The structure, morphologies and electrochemical performance of the samples obtained at different reaction times and solvothermal temperatures were investigated. The results show that the CoF2 spheres obtained at 200 °C for 20 h show better electrochemical performances, including a high initial discharge capacity, good capacity retention and high Coulombic efficiency. It can deliver a high initial discharge capacity of 537.8 mA•h•g−1 and keep 127.4 mA•h•g−1 after 30 cycles used as cathode materials for lithium‐ion batteries. The good electrochemical performances may be attributed to good crystallinity, porous structure and relatively intermediate sphere size.
Effect of Hydrogen Binding on Selective Recognition of Halide Anions
Authors: Du Juan , Kang Kang , Hu Jinchuan , Mao Lijun , Yuan Lihua , Feng Wen
Published: July 2016

The interplay of molecular rigidity enforced by interior or exterior hydrogen bonding and affinity for binding halide anions is described to demonstrate the effect of intramolecular hydrogen bonding in anion recognition process. To this end pyridine‐2,6‐dicarboxamides1and2, and aromatic oligoamides3and4containing intramolecular hydrogen bonds were explored for their ability in associating with tetrabutylammonium halide (Cl−, Br−, and I−). Binding constants in chloroform solution were calculated using nonlinear curve‐fitting method based on1H NMR titration experiments. The trimeric amide3, which adopts a crescent conformation as revealed by single‐crystal X‐ray diffraction analysis, strongly binds chloride anion with binding constant as high as 379 L·mol−1. This is more than 6 times greater than the binding constant for the control receptor2with a backbone that is only partially rigidified. The comparative data provided supportive information for rationalizing the observed affinity difference in binding halide anions in terms of local preorganization effected by interior or exterior hydrogen bonding.
One‐Pot Synthesis of Hantzsch Pyridines via NH4I Promoted Condensation of 1,3‐Dicarbonyl Compounds with DMSO and NH4OAc
Authors: Chang Liming , Lai Junyi , Yuan Gaoqing
Published: July 2016

A one‐pot synthesis of Hantzsch pyridines was achieved through NH4I‐promoted condensation of 1,3‐dicarbonyl compounds with DMSO and NH4OAc, in which the C4 of the pyridine rings was derived from DMSO and the nitrogen atom resulted from NH4OAc and NH4I. The target product could be obtained in moderate to excellent yields.
Voltammetric Behavior of 1,4‐Dimethoxypillar[m]arene[n]quinones
Authors: Saba Hina , An Jianggen , Yang Yong , Xue Min , Liu Yongsong
Published: July 2016

The electrochemical properties of a series of 1,4‐dimethoxypillar[m]arene[n]quinones (DMP[m]A[n]Qs) and the interactions between individual quinone units have been investigated on glassy carbon electrode in acetonitrile. All the quinone units showed relative electron uptake behavior except 1,4‐dimethoxypillar[5]quinones (DMP[5]Q). The results have shown that the electrochemical behavior of the DMP[m]A[n]Qs is comparatively different from that of their related linear quinone analogues. The resultant properties were attributed to the close proximity of redox‐active sites as well as the delocalization of electrons on the aromatic rings. Another aspect to be considered responsible for their electronic properties was suggested to be the electrostatic repulsions between adjacent quinone units in these complex structures. Current studies provide a better understanding on the voltammetric behavior of pillararene derivatives with different numbers of quinone units as well as their future scope in certain future electrochemical applications.
Basic Consideration of Monte Carlo Algorithm to Solve Fluid Equations for SOL/divertor Plasmas
Authors: Tatsumi R. , Homma Y. , Yamoto S. , Hatayama A.
Published: July 2016

Monte Carlo method is thought to be effective to solve fluid plasma equations for SOL/divertor plasmas, especially for three dimensional simulation. In the Monte Carlo algorithm based on a Lagrangian scheme, how to treat the Monte Carlo test particles at the calculation boundaries is not always trivial. In this paper, 1D diffusion equation with source terms has been solved with several different treatments of the boundaries in relatively a simple model. Comparison between the results and analytic solutions show that careful treatment of the boundary seems to be needed. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simultaneous detection of 93 synthetic cannabinoids by liquid chromatography‐tandem mass spectrometry and retrospective application to real forensic samples
Authors: Hess Cornelius , Murach Jacqueline , Krueger Lynn , Scharrenbroch Lisa , Unger Michael , Madea Burkhard , Sydow Konrad
Published: July 2016

The Internet is flooded with steadily changing synthetic cannabinoids in `Spice` products. In routine forensic work, it is difficult to keep the analytical methods for the detection of these analytes up to date. We describe a liquid chromatography‐tandem mass spectrometry method after liquid‐liquid extraction for the detection of 93 synthetic cannabinoids in human serum. The method was validated for selectivity and specificity, matrix effects, and analytical limits (<1 ng/mL for 81 substances) for qualitative analysis. A short quantitative validation regarding linearity and precision data was also conducted. The method was applied to 189 serum samples provided by police authorities. Sixty‐four samples (33.8%) were found positive for at least one synthetic cannabinoid, whereby MDMB‐CHMICA, AB‐CHMINACA, and 5 F‐PB‐22 were the substances most frequently detected. Consumption of these substances and plasma concentrations are linked to symptoms documented by the police. Six case reports are presented. Copyright © 2016 John Wiley & Sons, Ltd.
Protocol for meta‐analysis of temperature reduction in animal models of cardiac arrest
Authors: Olai H. , Thornéus G. , Watson H. , Macleod M.R. , Friberg H. , Rhodes J. , Nielsen N. , Cronberg T. , Deierborg T.
Published: July 2016

Targeted temperature management (TTM) of 32–34 °C has been the standard treatment for out‐of‐hospital cardiac arrest since clinical trials in 2002 showed benefits to survival and neurological outcome. Recently, this treatment has been challenged by another clinical trial showing no difference in outcome between TTM of 33 °C and 36 °C. This protocol describes the methodology for a meta‐analysis detailing temperature‐reducing interventions to treat global ischaemia in animal models. By combining relevant data sets in the literature, we will explore the experimental evidence for TTM. Our aims are to explain possible translational gaps and provide methodological considerations for future experimental research and clinical trials.
Phase‐Controlled Synthesis of Cu2SnS3 Nanocrystals: The Effect of Redox Conditions on the Initial Binary Cu2–xS Nucleation
Authors: Liang Qingshuang
Published: July 2016

In this work, it is shown that both pure zincblende and wurtzite structures of Cu2SnS3 (CTS) nanocrystals (NCs) have been synthesized by a facile one‐spot heating‐up procedure. By controlling the solvent ratios, different phase components of zincblende and wurtzite mix‐phase CTS NCs were also obtained. The effect of different precursors and surfactants on the phase selectivity of CTS NCs was investigated, and a phase‐controlled mechanism is proposed: the crystal structures of the resulting CTS NCs are related to the initial structure forms of the CuxS seeds, and the different phase structures are formed as a result of the initial redox conditions. When the reaction was conducted under reducing conditions, Cu2S (or Cu31S16) seeds were formed, leading to the formation of wurtzite CTS nanocrystals. When the conditions were less reducing, the initial CuS (or Cu1.84S) seeds resulted in the zincblende structure CTS nanocrystals.
Impact of biofuel development on Malaysian agriculture: a comparative statics, multicommodity, multistage production, partial equilibrium approach
Authors: Jafari Yaghoob , Othman Jamal
Published: July 2016

In light of the move toward a low carbon economy, Malaysia is currently promoting the production of palm oil‐based biodiesel. This study develops a multicommodity, multistage, comparative static, partial equilibrium model for the Malaysian agricultural sector to be used to examine the impact of shifts in domestic demand for palm oil‐based biofuel on the Malaysian agricultural sector. The model links explicitly factor markets, related outputs, and consumer preferences for biofuels. Model results demonstrate a clear converse relationship between the variables representing the competing activities within the same sector. An increase in domestic biofuel demand leads to an increase in biofuel output and primary factor uses while the outputs of competing uses, especially food and other non‐food products decline markedly.
Inhomogeneous distribution of Iba‐1 characterizes microglial pathology in Alzheimer's disease
Authors: Tischer Jasmin , Krueger Martin , Mueller Wolf , Staszewski Ori , Prinz Marco , Streit Wolfgang J. , Bechmann Ingo
Published: July 2016

Microglial dystrophy has recently been described as a morphological phenotype of microglia that differs from resting and activated states by spheroid formation and cytorrhexis. In thick sections immunolabeled for HLA‐DR or Iba‐1 dystrophic microglial processes lose their typical, homogeneous staining pattern and appear to be fragmented or clustered. In this study, we performed double immunofluorescence and electron microscopy to determine if this labeling pattern indeed reflects complete separation of microglial processes from the soma. Using Iba‐1/CD68 and Iba‐1/MHC class II, as microglial markers, we observed that isolated Iba‐1 fragments were still connected to each other by segments of the microglial process immune positive for CD68 or MHC class II. Ultrathin serial sections of two Iba‐1 fragments which appeared to be disconnected from each other at the light microscopical level revealed a still existing "bridge" with a diameter of around 0.182 µm. Therefore, microglial dystrophy may reflect alterations of the cytoskeleton ultimately leading to slow cytorrhexis. GLIA 2016;64:1562–1572
Guest Editors’ Introduction: CEOs’ Careers: Emerging Trends and Future Directions
Authors: Koyuncu Burak , Hamori Monika , Baruch Yehuda
Published: July 2016

The field of career studies is increasing in prominence and relevance for modern life in general and working life in particular.CEOs’ careers, especially, have received growing attention because their impact goes far beyond their personal sphere. Not surprisingly, this topic has been at the intersection of multiple literatures. In this introduction for the special issue onCEOs’ careers, we first review the different perspectives in studyingCEOs’ careers, and then offer several directions to integrate those multiple perspectives. The articles in this special issue not only provide us with comprehensive new knowledge onCEOs’ careers, but also represent valuable examples of how to integrate different perspectives on this topic. © 2016 Wiley Periodicals, Inc.
Searching events in AFM force‐extension curves: A wavelet approach
Authors: Benítez R. , Bolós V. J.
Published: July 2016

An algorithm, based on the wavelet scalogram energy, for automatically detecting events in force‐extension AFM force spectroscopy experiments is introduced. The events to be detected are characterized by a discontinuity in the signal. It is shown how the wavelet scalogram energy has different decay rates at different points depending on the degree of regularity of the signal, showing faster decay rates at regular points and slower rates at singular points (jumps). It is shown that these differences produce peaks in the scalogram energy plot at the event points. Finally, the algorithm is illustrated in a tether analysis experiment by using it for the detection of events in the AFM force‐extension curves susceptible to being considered tethers. Microsc. Res. Tech. 80:153–159, 2017. © 2016 Wiley Periodicals, Inc.
Maghemite nanoparticle‐decorated hollow fiber electromembrane extraction combined with dispersive liquid–liquid microextraction for determination of thymol from Carum copticum
Authors: Khajeh Mostafa , Pedersen‐Bjergaard Stig , Bohlooli Mousa , Barkhordar Afsaneh , Ghaffari‐Moghaddam Mansour
Published: July 2016

BACKGROUND

A novel technique using maghemite nanoparticle‐decorated hollow fibers to assist electromembrane extraction is proposed. Electromembrane extraction combined with dispersive liquid–liquid microextraction (EME‐DLLME) was applied for the extraction of thymol from Carum copticum, followed by gas chromatography with flame ionization detection (GC‐FID).

RESULTS

The use of maghemite nanoparticle‐decorated hollow fibers was found to improve the extraction efficiency of thymol significantly. Important operational parameters, including pH of acceptor phase, extraction time, voltage and temperature, were investigated and optimized. At the optimal conditions, linearity in the range 4–1800 µg L−1 with a determination coefficient of 0.9996 was obtained. The limit of detection was 0.11 µg L−1 (S/N = 3) and the pre‐concentration factor was 200. The intra‐ and inter‐day precision was 5.9 and 2.2% respectively. The intra‐ and inter‐day accuracy was higher than 93.6%.

CONCLUSION

The results indicated that EME‐DLLME/GC‐FID is a useful technique for the extraction and determination of thymol in C copticum. © 2016 Society of Chemical Industry
Synthesis and evaluation of a maltose‐bonded silica gel stationary phase for hydrophilic interaction chromatography and its application in Ginkgo Biloba extract separation in two‐dimensional systems
Authors: Sheng Qianying , Yang Kaiya , Ke Yanxiong , Liang Xinmiao , Lan Minbo
Published: July 2016

Maltose covalently bonded to silica was prepared by using carbonyl diimidazole as a cross‐linker and employed as a stationary phase for hydrophilic interaction liquid chromatography. The column efficiency and the effect of water content, buffer concentration, and pH value influenced on retention were investigated. The separation or enrichment selectivity was also studied with nucleosides, saccharides, amino acids, peptides, and glycopeptides. The results indicated that the stationary phase processed good separation efficiency and separation selectivity in hydrophilic interaction liquid chromatography mode. Moreover, a two‐dimensional hydrophilic interaction liquid chromatography× reversed‐phase liquid chromatography method with high orthogonality was developed to analyze the Ginkgo Biloba extract fractions. The development of this two‐dimensional chromatographic system would be an effective tool for the separation of complex samples of different polarities and contents.
Collocation discretization for an integral equation in ocean acoustics with depth‐dependent speed of sound
Authors: Lechleiter Armin , Rienmüller Tobias
Published: July 2016

We analyze two collocation schemes for the Helmholtz equation with depth‐dependent sonic wave velocity, modeling time‐harmonic acoustic wave propagation in a three‐dimensional inhomogeneous ocean of finite height. Both discretization schemes are derived from a periodized version of the Lippmann‐Schwinger integral equation that equivalently describes the sound wave. The eigenfunctions of the corresponding periodized integral operator consist of trigonometric polynomials in the horizontal variables and eigenfunctions to some Sturm‐Liouville operator linked to the background profile of the sonic wave velocity in the vertical variable. Applying an interpolation projection onto a space spanned by finitely many of these eigenfunctions to either the unknown periodized wave field or the integral operator yields two different collocation schemes. A convergence estimate of Sloan [J. Approx. Theory, 39:97–117, 1983] on non‐polynomial interpolation allows to show converge of both schemes, together with algebraic convergence rates depending on the smoothness of the inhomogeneity and the source. Copyright © 2016 John Wiley & Sons, Ltd.
Conductive elastomer composites with low percolation threshold based on carbon black and epoxidized natural rubber
Authors: Salaeh Subhan , Boiteux Gisèle , Cassagnau Philippe , Nakason Charoen
Published: July 2016

Conductive elastomer composite based on carbon black (CB) filled epoxidized natural rubber with 50 mol% epoxide (ENR‐50) were prepared using two types of CB: high abrasion furnace (HAF) and extra conductive furnace (ECF) with different loading levels. It was found that the ENR‐50/ECF composite had the maximum tensile strength at lower loading of 10 phr as compared with the ENR‐50/HAF composite at 20 phr. Furthermore, the Kraus's relation revealed that two types of CB provide different degree of reinforcement. Incorporation of CB leads to increase permittivity, loss factor and conductivity of the composites. However, the ENR‐50/ECF composites show higher conductivity than that of the ENR‐50/HAF composites. The electrical percolation thresholds (pc) of ENR‐50/HAF and ENR‐50/ECF composites were observed at loading levels of CB = 12.0 and 6.3 vol%, respectively. These are very low percolation thresholds of the conductive elastomer composites with CB. POLYM. COMPOS., 39:1835–1844, 2018. © 2016 Society of Plastics Engineers
A standardized production pipeline for high profile targets fromMycobacterium tuberculosis
Authors: Milewski Morlin C. , Broger Tobias , Kirkpatrick Joanna , Filomena Angela , Komadina Dana , Schneiderhan‐Marra Nicole , Wilmanns Matthias , Parret Annabel H. A.
Published: July 2016

Purpose

Tuberculosis is still a major threat to global health. New tools and strategies to produce disease‐related proteins are quintessential for the development of novel vaccines and diagnostic markers.

Experimental design

To obtain recombinant proteins fromMycobacterium tuberculosis(Mtb) for use in clinical applications, a standardized procedure was developed that includes subcloning, protein expression inMycobacterium smegmatisand protein purification using chromatography. The potential for the different protein targets to serve as diagnostic markers for tuberculosis was established using multiplex immunoassays.

Results

Twelve soluble proteins from Mtb, including one protein complex, were purified to near‐homogeneity following recombinant expression inM. smegmatis. Protein purity was assessed both by size exclusion chromatography and MS. Multiplex serological testing of the final protein preparations showed that all but one protein displayed a clear antibody response in serum samples from 278 tuberculosis patients.

Conclusion and clinical relevance

The established workflow comprises a simple, cost‐effective, and scalable pipeline for production of soluble proteins from Mtb and can be used to prioritize immunogenic proteins suitable for use as diagnostic markers.
Teleocidin A2 inhibits human proteinase‐activated receptor 2 signaling in tumor cells
Authors: Stahn Sonja , Thelen Lisa , Albrecht Ina‐Maria , Bitzer Jens , Henkel Thomas , Teusch Nicole Elisabeth
Published: July 2016

Enhanced expression of the proteinase‐activated receptor 2 (PAR2) is linked to cell proliferation and migration in many cancer cell types. The role of PAR2 in cancer progression strongly illustrates the need for PAR2‐inhibiting compounds. However, to date, potent and selective PAR2 antagonists have not been reported. The natural product teleocidin A2 was characterized against PAR2‐activating peptide SLIGKV‐NH2, and trypsin‐induced PAR2‐dependent intracellular Ca2+ mobilization in tumor and in primary endothelial or epithelial cells. Further biochemical and cell‐based studies were conducted to evaluate teleocidin specificity. The antagonizing effect of teleocidin A2 was confirmed in PAR2‐dependent cell migration and rearrangement of actin cytoskeleton of human breast adenocarcinoma cell line (MDA‐MB 231) breast cancer cells. Teleocidin A2 antagonizes PAR2‐dependent intracellular Ca2+ mobilization induced by either SLIGKV‐NH2 or trypsin with IC50 values from 15 to 25 nmol/L in MDA‐MB 231, lung carcinoma cell line, and human umbilical vein endothelial cell. Half maximal inhibition of either PAR1 or P2Y receptor‐dependent Ca2+ release is only achieved with 10‐ to 20‐fold higher concentrations of teleocidin A2. In low nanomolar concentrations, teleocidin A2 reverses both SLIGKV‐NH2 and trypsin‐mediated PAR2‐dependent migration of MDA‐MB 231 cells, and has no effect itself on cell migration and no effect on cell viability. Teleocidin A2 further controls PAR2‐induced actin cytoskeleton rearrangement of MDA‐MB 231 cells. Thus, for the first time, the small molecule natural product teleocidin A2 exhibiting PAR2 antagonism in the low nanomolar range with potent antimigratory activity is described.