bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal Discounting Mechanisms of Future‐oriented Coping: Evidence from Delay Discounting and Task Prioritization Paradigms
Authors: Gan Yiqun , Wang Yu , Meng Ran , Wen Min , Zhou Guangyu , Lu Yingyue , Miao Miao
Published: March 2015

Four studies were conducted to examine the relationship between future‐oriented coping and temporal discounting under different situational conditions. In Study 1, 138 participants were primed with either stressful or neutral stimuli, followed by a delay‐discounting task. In Study 2, 118 participants were primed with either stressful or neutral stimuli, followed by a task‐prioritization activity. The results of both studies indicated that future‐oriented coping had a significant negative association with temporal discounting or the number of rational choices in the neutral‐priming condition, but the relationship was not significant in the stress‐priming condition. In Study 3, qualitative data revealed that the major reason for shifting choices from larger but later payoffs to smaller but sooner rewards in a stressful condition was to reduce the stressful mood, create a positive mood, and promote a sense of accomplishment. This explanation was corroborated by Study 4, in which one group was allowed to choose an immediate payoff and the other group was blocked from choosing that immediate payoff. We confirmed that post‐test anxiety was significantly lower in the immediate payoff group compared with the delayed‐payoff group in proactive and preventive coping, using pre‐test anxiety as a covariate. Preventive coping helped to reduce anxiety levels in a stressful condition only when there was a choice to obtain an immediate payoff. These findings underscore the relationship between future‐oriented coping and temporal discounting, as well as the flexibility of discounting in the face of stress. Copyright © 2015 John Wiley & Sons, Ltd.
Multi‐spectroscopic methods investigation on the interaction of tenoxicam with DNA
Authors: Liu Bing‐Mi , Zhang Jun , Liu Yang , Zhang Li‐Ping , Ma Ping , Wang Xin , Liu Bin
Published: March 2015

Non‐steroidal anti‐inflammatory drugs (NSAIDs) show chemopreventive and chemosuppressive effects on various cancer cell lines. They exert anticancer activities by inhibiting both at the protein level and/or at the transcription level. Thus, in this paper, the interaction between tenoxicam (TXM) and calf thymus DNA (ct‐DNA) was investigated by UV–visible light, fluorescence, viscosity experiments and DNA melting studies. The results showed that TXM could bind to ct‐DNA in the groove binding mode. The binding constants were 7.67 × 103 and 5.48 × 103 M−1 at 293 and 300 K, respectively. Furthermore, the calculated thermodynamic parameters suggested that hydrogen bonds or van der Waals force might play an important role in the binding of TXM to ct‐DNA. The obtained results should give new insight into the pharmacological activity of TXM. Copyright © 2015 John Wiley & Sons, Ltd.
Analyzing the hydrodynamic and crowding evolution of aqueous hydroxyapatite‐gelatin networks: Digging deeper into bone scaffold design variables
Authors: Sartuqui Javier , D’ Elía Noelia , Gravina A. Noel , Messina Paula V.
Published: March 2015

The hydration of the polypeptide network is a determinant factor to be controlled on behalf of the design of precise functional tissue scaffolding. Here we present an exhaustive study of the hydrodynamic and crowding evolution of aqueous gelatin‐hydroxyapatite systems with the aim of increasing the knowledge about the biomimesis of collagen mineralization; and how it can be manipulated for the preparation of collagenous derived frameworks with specific morphological characteristics. The solution's density and viscosity evaluation measurements in combination with spectroscopic techniques revealed that there is a progressive association of protein chain that can be influenced by the amount of hydroxyapatite nanorods. Gelatin and additives’ concentration effect on the morphology of the gelatin scaffolds was investigated. Transverse and longitudinal sections of the obtained scaffolds were taken and analyzed using optical microscopy. It can be seen that the porous size and shape of gelatin assemblies can be easily adjusted by controlling the gelatin/HAp ratio in the solution used as template in agreement with our statement. © 2015 Wiley Periodicals, Inc. Biopolymers 103: 393–405, 2015.
Enhanced production of branched‐chain fatty acids by replacing β‐ketoacyl‐(acyl‐carrier‐protein) synthase III (FabH)
Authors: Jiang Wen , Jiang Yanfang , Bentley Gayle J. , Liu Di , Xiao Yi , Zhang Fuzhong
Published: March 2015

Branched‐chain fatty acids (BCFAs) are important precursors for the production of advanced biofuels with improved cold‐flow properties. Previous efforts in engineering type II fatty acid synthase (FAS) for BCFA production suffered from low titers and/or the co‐production of a large amount of straight‐chain fatty acids (SCFAs), making it nearly impossible for further conversion of BCFAs to branched biofuels. Synthesis of both SCFAs and BCFAs requires FabH, the only β‐ketoacyl‐(acyl‐carrier‐protein) synthase in Escherichia coli that catalyzes the initial condensation reaction between malonyl‐ACP and a short‐chain acyl‐CoA. In this study, we demonstrated that replacement of the acetyl‐CoA‐specific E. coli FabH with a branched‐chain‐acyl‐CoA‐specific FabH directed the flux to the synthesis of BCFAs, resulting in a significant enhancement in BCFA titer compared to a strain containing both acetyl‐CoA‐ and branched‐chain‐acyl‐CoA‐specific FabHs. We further demonstrated that the composition of BCFAs can be tuned by engineering the upstream pathway to control the supply of different branched‐chain acyl‐CoAs, leading to the production either even‐chain‐iso‐, odd‐chain‐iso‐, or odd‐chain‐anteiso‐BCFAs separately. Overall, the top‐performing strain from this study produced BCFAs at 126 mg/L, comprising 52% of the total free fatty acids. Biotechnol. Bioeng. 2015;112: 1613–1622. © 2015 Wiley Periodicals, Inc.
Metabolic control of respiratory levels in coenzyme Q biosynthesis‐deficient Escherichia coli strains leading to fine‐tune aerobic lactate fermentation
Authors: Wu Hui , Bennett George N. , San Ka‐Yiu
Published: March 2015

A novel strategy to finely control the electron transfer chain (ETC) activity of Escherichia coli was established. In this study, the fine‐tuning of the ubiquinone biosynthesis pathway was applied to further controlling ETC function in coenzyme Q8 biosynthesis‐deficient E. coli strains, HW108 and HW109, which contain mutations in ubiE and ubiG, respectively. A competing pathway on the intermediate substrates of the Q8 synthesis pathway, catalyzed by diphosphate:4‐hydroxybenzoate geranyltransferase (PGT‐1) of Lithospermum erythrorhizon, was introduced into these mutant strains. A nearly theoretical yield of lactate production can be achieved under fully aerobic conditions via an in vivo, genetically fine‐tunable means to further control the activity of the ETC of the Q8 biosynthesis‐deficient E. coli strains. Biotechnol. Bioeng. 2015;112: 1720–1726. © 2015 Wiley Periodicals, Inc.
Building terpene production platforms in yeast
Authors: Zhuang Xun , Chappell Joe
Published: March 2015

Plants and microbes commonly make terpenes and terpenoids in small amounts and as complex mixtures, and their chemical synthesis is often costly and inefficient. Hence, there are many efforts to create robust and efficient biological production platforms for this interesting class of molecules. In this study, our effort was directed towards building a yeast production platform using an unbiased genetic selection approach. Yeast strain BY4741 was subjected to EMS mutagenesis, followed by selection for growth in the presence of nystatin, squalestatin, and exogenous cholesterol. This unbiased screen selected for mutant yeast lines having a dispensable mevalonate pathway and containing uncharacterized SUE (sterol uptake enhancement) mutations supporting aerobic uptake of exogenous sterol. These mutants were next screened for high level accumulation of farnesol (FOH), an indicator for high level accumulation of the key intermediate FPP, farnesyl diphosphate. To further improve the FPP pool in these mutants, insertional mutations into the ERG9 gene (coding for squalene synthase) were introduced into those lines capable of accumulating ≥50 mg farnesol/L. This generated another series of lines that accumulated farnesol levels over 70 mg/L in small‐scale shake cultures. To evaluate the utility of these lines as a general production platform for specific terpenes, select SUE/erg9 lines were transformed with a vector harboring the Hyoscyamus muticus premnaspirodiene synthase (HPS) gene encoding for a sesquiterpene synthase. The new yeast line ZX178‐08 accumulated the highest level of premnaspirodiene, up to 116 mg/L, with FOH levels of 23.6 mg/L. In comparison, the parental line BY4741 accumulated 10 times less premnaspirodiene, 10.94 mg/L, with no farnesol detectable. Co‐expression of the HPS gene with an amino‐terminal truncated, catalytic form of the hamster HMGR gene, tHMGR, increased premnaspirodiene accumulation to 170.23 ± 30.44 mg/L, almost a 50% increase. Further utility of this yeast line was demonstrated for triterpene production. When engineered for the production of a non‐native triterpene, Zx178‐08 accumulated upwards of 60 mg/L of botryococcene. To engineer more native triterpene accumulation, additional insertion mutants into the ERG1 gene (coding for squalene epoxidase) were evaluated. Insertion of a simple selection marker followed by over‐expression of a heterologous squalene synthase gene resulted in greater than 85 mg/L of squalene. However, when the ERG1 insertional mutant included chromosomal insertion of a truncated, heterologous HMGR gene, squalene production was more than tripled to 270 mg/L. These results are discussed in comparison to other recently developed terpene production platforms. Biotechnol. Bioeng. 2015;112: 1854–1864. © 2015 Wiley Periodicals, Inc.
Fibrin gels engineered with pro‐angiogenic growth factors promote engraftment of pancreatic islets in extrahepatic sites in mice
Authors: Najjar Mejdi , Manzoli Vita , Abreu Maria , Villa Chiara , Martino Mikaël M. , Molano R. Damaris , Torrente Yvan , Pileggi Antonello , Inverardi Luca , Ricordi Camillo , Hubbell Jeffrey A. , Tomei Alice A.
Published: March 2015

With a view toward reduction of graft loss, we explored pancreatic islet transplantation within fibrin matrices rendered pro‐angiogenic by incorporation of minimal doses of vascular endothelial growth factor‐A165 and platelet‐derived growth factor‐BB presented complexed to a fibrin‐bound integrin‐binding fibronectin domain. Engineered matrices allowed for extended release of pro‐angiogenic factors and for their synergistic signaling with extracellular matrix‐binding domains in the post‐transplant period. Aprotinin addition delayed matrix degradation and prolonged pro‐angiogenic factor availability within the graft. Both subcutaneous (SC) and epididymal fat pad (EFP) sites were evaluated. We show that in the SC site, diabetes reversal in mice transplanted with 1,000 IEQ of syngeneic islets was not observed for islets transplanted alone, while engineered matrices resulted in a diabetes median reversal time (MDRT) of 38 days. In the EFP site, the MDRT with 250 IEQ of syngeneic islets within the engineered matrices was 24 days versus 86 days for islets transplanted alone. Improved function of engineered grafts was associated with enhanced and earlier (by day 7) angiogenesis. Our findings show that by engineering the transplant site to promote prompt re‐vascularization, engraftment and long‐term function of islet grafts can be improved in relevant extrahepatic sites. Biotechnol. Bioeng. 2015;112: 1916–1926. © 2015 Wiley Periodicals, Inc.
Consolidated bioprocessing of starchy substrates into ethanol by industrial Saccharomyces cerevisiae strains secreting fungal amylases
Authors: Favaro Lorenzo , Viktor Marko J. , Rose Shaunita H. , Viljoen‐Bloom Marinda , van Zyl Willem H. , Basaglia Marina , Cagnin Lorenzo , Casella Sergio
Published: March 2015

The development of a yeast strain that converts raw starch to ethanol in one step (called Consolidated Bioprocessing, CBP) could significantly reduce the commercial costs of starch‐based bioethanol. An efficient amylolytic Saccharomyces cerevisiae strain suitable for industrial bioethanol production was developed in this study. Codon‐optimized variants of the Thermomyces lanuginosus glucoamylase (TLG1) and Saccharomycopsis fibuligera α‐amylase (SFA1) genes were δ‐integrated into two S. cerevisiae yeast with promising industrial traits, i.e., strains M2n and MEL2. The recombinant M2n[TLG1‐SFA1] and MEL2[TLG1‐SFA1] yeast displayed high enzyme activities on soluble and raw starch (up to 8118 and 4461 nkat/g dry cell weight, respectively) and produced about 64 g/L ethanol from 200 g/L raw corn starch in a bioreactor, corresponding to 55% of the theoretical maximum ethanol yield (g of ethanol/g of available glucose equivalent). Their starch‐to‐ethanol conversion efficiencies were even higher on natural sorghum and triticale substrates (62 and 73% of the theoretical yield, respectively). This is the first report of direct ethanol production from natural starchy substrates (without any pre‐treatment or commercial enzyme addition) using industrial yeast strains co‐secreting both a glucoamylase and α‐amylase. Biotechnol. Bioeng. 2015;112: 1751–1760. © 2015 Wiley Periodicals, Inc.
Do your policies make the grade for handling large‐scale academic misconduct?
Authors: Porter Michael
Published: March 2015

As online exams and electronic tools flourish to ensure student assignments and exams meet today's expectations for electronic efficiency, students increasingly find more creative ways to cheat. Tech‐savvy students can create avenues for large‐scale cheating, especially by electronic means.
Follow steps to wrap up employee misconduct investigations
Authors: Sievert Justin P.
Published: March 2015

During the past couple of months, I have addressed the essential elements necessary in preparing for an employee misconduct investigation within your unit as well as best practices to implement during the discovery process.
Re‐examine intern programs to ensure compliance with FLSA
Authors: Wilson Mark
Published: March 2015

In this highly competitive employment market, colleges can certainly afford to be highly selective when choosing the best candidates for their internship programs. But colleges cannot afford to be nonchalant about the design and intent of their internship programs.
Ensure FERPA training identifies which records aren't subject to FERPA
Authors: Rainsberger Richard
Published: March 2015

One of the best tips I received about answering an essay examination question was to first take five minutes and think about what I was going to say and write an outline of what I wanted to include in my response.
Hepatocyte‐Specific Delivery of siRNAs Conjugated to Novel Non‐nucleosidic Trivalent N‐Acetylgalactosamine Elicits Robust Gene Silencing in Vivo
Authors: Rajeev Kallanthottathil G. , Nair Jayaprakash K. , Jayaraman Muthusamy , Charisse Klaus , Taneja Nate , O'Shea Jonathan , Willoughby Jennifer L. S. , Yucius Kristina , Nguyen Tuyen , Shulga‐Morskaya Svetlana , Milstein Stuart , Liebow Abigail , Querbes William , Borodovsky Anna , Fitzgerald Kevin , Maier Martin A. , Manoharan Muthiah
Published: March 2015

We recently demonstrated that siRNAs conjugated to triantennary N‐acetylgalactosamine (GalNAc) induce robust RNAi‐mediated gene silencing in the liver, owing to uptake mediated by the asialoglycoprotein receptor (ASGPR). Novel monovalent GalNAc units, based on a non‐nucleosidic linker, were developed to yield simplified trivalent GalNAc‐conjugated oligonucleotides under solid‐phase synthesis conditions. Synthesis of oligonucleotide conjugates using monovalent GalNAc building blocks required fewer synthetic steps compared to the previously optimized triantennary GalNAc construct. The redesigned trivalent GalNAc ligand maintained optimal valency, spatial orientation, and distance between the sugar moieties for proper recognition by ASGPR. siRNA conjugates were synthesized by sequential covalent attachment of the trivalent GalNAc to the 3′‐end of the sense strand and resulted in a conjugate with in vitro and in vivo potency similar to that of the parent trivalent GalNAc conjugate design.
A Facile Approach to Fabricate an N‐Doped Mesoporous Graphene/Nanodiamond Hybrid Nanocomposite with Synergistically Enhanced Catalysis
Authors: Zhao Zhongkui , Dai Yitao , Ge Guifang , Mao Qing , Rong Zeming , Wang Guiru
Published: March 2015

Owing to their unique structural features and surface properties, graphene and nanodiamond have attracted tremendous attention in diverse fields. However, restacking of graphene and reagglomeration of dispersed nanodiamond inevitably depress their catalytic properties. Herein, inspired by the historic discovery of “pillared clay”, we successfully realized the simultaneous inhibition of their restacking by fabricating a N‐doped mesoporous graphene/nanodiamond (N‐RGO/ND) nanocomposite by a facile wet‐chemical approach. The electrocatalytic oxygen reduction reaction (ORR) and the thermocatalytic oxidant‐free and steam‐free direct dehydrogenation (DDH) of ethylbenzene were used to examine its catalytic properties. The nanocomposite showed synergistically improved catalytic DDH and electrocatalytic ORR activity relative to that of the individual components, which can be ascribed to synergy between graphene and nanodiamond and to the large surface area, well‐ordered mesoporous structure, small crystalline size, and rich defect and CO surface features. Moreover, the developed synthetic strategy in this work can be extended to diverse N‐doped nanocomposites from dispersion‐required carbon precursors.
Dispersive solid phase extraction combined with dispersive liquid–liquid extraction for the determination of BTEX in soil samples: ant colony optimization–artificial neural network
Authors: Khajeh Mostafa , Moosavi‐Movahedi Ali Akbar , Shakeri Mohammad , Musavi Zadeh Fatemeh , Khajeh Ahmad , Bohlooli Mousa
Published: March 2015

In this study, dispersive solid phase extraction combined with dispersive liquid–liquid extraction has been developed for the extraction of benzene, toluene, ethylbenzene, and xylenes isomers (BTEX) in soil samples prior to gas chromatography–mass spectrometry. The BTEX were extracted from soil sample into acetonitrile by dispersive solid phase extraction method, and the extract was then used as dispersive solvent in dispersive liquid–liquid extraction procedure. Ant colony optimization–artificial neural network (ACO–ANN) has been employed to develop the model for simulation and optimization of this method. The volume of dispersive solvent, volume of extraction solvent, extraction time, and ultrasonic time were the input variables, while the multiple response function (Rm) of analytes was the output. The optimum operating condition was then determined by ant colony optimization method. At the optimum conditions, the limit of detections of 0.12–0.75 ng g−1 was obtained for the BTEX. The developed procedure was then applied to the extraction and determination of BTEX in the soil samples and one certified soil. Copyright © 2015 John Wiley & Sons, Ltd.
Gold Carbene or Carbenoid: Is There a Difference?
Authors: Wang Yahui , Muratore Michael E. , Echavarren Antonio M.
Published: March 2015

By reviewing the recent progress on the elucidation of the structure of gold carbenes and the definitions of metal carbenes and carbenoids, we recommend to use the term gold carbene to describe gold carbene‐like intermediates, regardless of whether the carbene or carbocation extreme resonance dominates. Gold carbenes, because of the weak metal‐to‐carbene π‐back‐donation and their strongly electrophilic reactivity, could be classified into the broader family of Fischer carbenes, although their behavior and properties are very specific.
An updated look at actin dynamics in filopodia
Authors: Leijnse Natascha , Oddershede Lene B. , Bendix Poul M.
Published: March 2015

Cells dynamically interact with and probe their environment by growing finger‐like structures named filopodia. The dynamics of filopodia are mainly caused by the actin rich core or shaft which sits inside the filopodial membrane and continuously undergoes changes like growth, shrinking, bending, and rotation. Recent experiments combining advanced imaging and manipulation tools have provided detailed quantitative data on the correlation between mechanical properties of filopodia, their molecular composition, and the dynamic architecture of the actin structure. These experiments have revealed how retrograde flow and twisting of the actin shaft within filopodia can generate traction on external substrates. Previously, the mechanism behind filopodial pulling was mainly attributed to retrograde flow of actin, but recent experiments have shown that rotational dynamics can also contribute to the traction force. Although force measurements have indicated a step‐like behavior in filopodial pulling, no direct evidence has been provided to link this behavior to a molecular motor like myosin. Therefore, the underlying biochemical and mechanical mechanisms behind filopodial force generation still remain to be resolved. © 2015 Wiley Periodicals, Inc.
Intra‐ and Intermolecular Dispersion Interactions in [n]Cycloparaphenylenes: Do They Influence Their Structural and Electronic Properties?
Authors: Climent‐Medina José‐Vicente , Pérez‐Jiménez Ángel‐José , Moral Mónica , San‐Fabián Emilio , Sancho‐García Juan‐Carlos
Published: March 2015

Cycloparaphenylenes (CPPs) are nanosized structures with unique isolated and bulk properties, and are synthetic targets for the template‐driven bottom‐up synthesis of carbon nanotubes. Thus, a systematic understanding of the supramolecular order at the nanoscale is of utmost relevance for molecular engineering. In this study, it is found that intramolecular noncovalent (dispersion) interactions must be taken into account for obtaining accurate estimates of the structural and optoelectronic properties of [n]CPP compounds, and their influence as the number of repeat units increases from n=4 to n=12 is also analyzed, both in the gas phase and in solution. The supramolecular self‐assembly, for which both intra‐ and intermolecular noncovalent interactions are relevant, of [6]CPP is also investigated by calculating the binding energies of dimers taken along several crystal directions. These are also used to estimate the cohesive energy of the crystal, which is compared to the value obtained by means of dispersion‐corrected DFT calculations using periodic boundary conditions. The reasonable agreement between both computational strategies points towards a first estimate of the [6]CPP cohesive energy of around 50 kcal mol−1.
Modulating the Solubilities of Ionic Liquid Components in Aqueous–Ionic Liquid Biphasic Systems: A Q‐NMR Investigation
Authors: Atanassova Maria , Mazan Valérie , Billard Isabelle
Published: March 2015

Aqueous–ionic liquid (A–IL) biphasic systems have been examined in terms of deuterated water, acid, and IL cation and anion mutual solubilities in the upper (water‐rich, in mole fraction) and lower phase of aqueous/IL biphasic systems at ambient temperature. The biphasic mixtures were composed of deuterated acids of various concentrations (mainly DCl, DNO3, and DClO4 from 10−2 to 10−4 M) and five ionic liquids of the imidazolium family with a hydrophobic anion (CF3SO2)2N−, that is, [C1Cnim][Tf2N], (n=2, 4, 6, 8 and 10). The analytical techniques applied were 1H NMR, 19F NMR, Karl–Fischer titration, pH potentiometry for IL cations and anions, and water and acid determination. The effects of the ionic strength (μ=0.1 M NaCl and NaNO3 as well as μ=0.1 M, 0.2 M and 0.4 M NaClO4, according to the investigated acid), the nature of the IL cation, and the nature of the mineral acid on the solubilities of the (D2O, D+, Tf2N−, C1Cnim+) entities in the lower or upper phases were determined. The addition of sodium perchlorate was found to enhance the Tf2N− solubility while inhibiting the solubility of the ionic liquid cation. Differences in IL cation and anion solubilities of up to 42 mM were evidenced. The consequences for the characterization of the aqueous biphasic system, the solvent extraction process of the metal ions, and the ecological impact of the ILs are discussed.
Intravenous Furosemide for Acute Decompensated Congestive Heart Failure: What Is the Evidence?
Authors: Owen DRJ , MacAllister R , Sofat R
Published: March 2015

Use of intravenous furosemide rather than oral administration in acute decompensated congestive cardiac failure is universally recommended in international guidelines. We argue that this recommendation is not supported by the existing evidence, and suggest that trials should be performed to determine whether larger doses of oral furosemide should be prescribed prior to an IV switch. This could reduce length of hospital admissions and allow for more patients to be managed in the primary care setting.
Effects of Palonosetron on Perioperative Cardiovascular Complications in Patients Undergoing Noncardiac Surgery With General Anesthesia: A Retrospective Cohort Study
Authors: Min JJ , Kim HJ , Jung S‐Y , Kim BG , Kwon K , Jung H‐J , Kim TK , Hong DM , Park B‐J , Jeon Y
Published: March 2015

We retrospectively investigated whether palonosetron administered during the induction of general anesthesia is associated with an increased risk of perioperative cardiovascular complications in a single tertiary center cohort consisting of 4,517 palonosetron‐exposed patients and 4,517 propensity score‐matched patients without palonosetron exposure. The primary endpoint was a composite of perioperative cardiovascular complications, including intraoperative cardiac arrhythmia, intraoperative cardiac death, and myocardial injury within the first postoperative week, and there was no significant difference between the groups (odds ratio [OR] = 1.04; 95% confidence interval [CI] = 0.92–1.19). As secondary endpoints, intraoperative cardioversion, cardiac compression, use of cardiovascular drugs, postoperative hospital stay, and in‐hospital mortality showed no differences between the groups. However, the palonosetron group showed decreased intraoperative hypotension (OR = 0.88; 95% CI = 0.79–0.97) and length of postoperative intensive care unit (ICU) stay (4.26 ± 9.86 vs. 6.14 ± 16.75; P = 0.026). Palonosetron did not increase the rate of perioperative cardiovascular complications, and can therefore be used safely during anesthetic induction.
Dynamic model of direct matrix converter and its experimental validation
Authors: Kordonis A. , Hikihara T.
Published: March 2015

Power electronics is a major candidate in the ongoing research of electrical power grids because they can provide better control with more information (voltage ratio, efficiency, power flow direction, etc.) than the all‐passive solutions such as transformers and so forth. Power electronic transformer has the possibility to replace the conventional one by ac/ac matrix converter with high‐frequency compact electronic transformers. In this work, a dynamic model of matrix converter is studied and issues such as efficiency, voltage ratio limitation, and transient behavior are discussed and the equivalent numerical calculations are presented. Moreover, an experimental converter is built to validate the numerical results and also to describe the switching frequency impact on the operation. It is concluded that the control creates voltage ratio saturation and high‐switching frequency results in lower efficiency values. On the other hand, efficiency can be increased by using resonances of the circuit, which can also provide higher operating frequencies. Copyright © 2015 John Wiley & Sons, Ltd.
A 6‐Gbps/lane receiver for a clock‐forwarded link in 65‐nm CMOS process
Authors: Ahn Keun‐Seon , Yoo Changsik
Published: March 2015

For a 6‐Gbps/lane clock‐forwarded link, a wireline receiver has been developed. The phases of the sampling clocks are aligned to the center of the input data eye by a clock and data recovery (CDR) circuit. In the CDR circuit, the sampling clock phases are rotated by a phase rotating phase locked loop (PLL). A three‐tap decision feedback equalizer (DFE) compensates for the loss of cable together with a continuous‐time linear equalizer (CTLE) to ensure sufficient eye opening for the CDR circuit to find the optimum sampling phase. The DFE coefficients are adaptively calculated based on the data and edge samples. Implemented in a 65‐nm CMOS process, the three‐lane 6‐Gbps/lane receiver for a clock‐forwarded link occupies 0.63 mm2 including pads and consumes 288 mA from a 1.2‐V supply. Copyright © 2015 John Wiley & Sons, Ltd.
Exploring the accuracy of capturing snapshots in large‐scale P2P IPTV systems
Authors: Wang Haizhou , Chen Xingshu , Wang Wenxian , Chan Mei Ya
Published: March 2015

With the growing maturity of peer‐to‐peer (P2P) technology, Internet protocol television (IPTV) applications based on that gained great success commercially and have attracted more and more attentions from both industry and academia. Currently, the active measurement method based on crawler technology is the most popular and effective one to study P2P IPTV systems. Existing measurement results revealed that accuracy of captured overlay snapshots depends on the crawling speed of crawler system. In order to capture more accurate overlay snapshots of P2P IPTV system, we developed a very fast and efficient distributed crawler system using the distributed architecture and peer degree‐rank mechanism. In this paper, we first introduce the architectures of PPTV channel‐list resource distribution and the whole system, which is the most popular and largest instance of P2P IPTV applications nowadays. Subsequently, this paper evaluates the crawling results of two dedicated crawlers capturing from peer‐list servers and ordinary peers, respectively. Finally, we propose a fast and accurate dedicated crawler system based on distributed architecture and peer degree rank for PPTV. The experiment results show that the performance of our distributed crawler system is much better than other existing crawler systems. Specifically, our distributed crawler can track a very popular channel with about 7200 online users in 30 s. It is also reasonable to believe that our distributed crawler system can capture complete overlay snapshots. To the best of our knowledge, our study work is the first to explore capturing accurate overlay snapshots of large‐scale P2P IPTV applications. Our crawler system can provide a good solution for capturing more accurate overlay snapshots of PPTV system and can also be used to help researchers to design crawler systems for other P2P IPTV systems. Copyright © 2015 John Wiley & Sons, Ltd.
Longitudinal examination of infant baseline and reactivity cortisol from ages 7 to 16 months
Authors: Martinez‐Torteya Cecilia , Muzik Maria , McGinnis Ellen W. , Rosenblum Katherine L. , Bocknek Erika L. , Beeghly Marjorie , DeCator Draycen , Abelson James L.
Published: March 2015

This study characterized the longitudinal evolution of HPA axis functioning from 7 to 16 months of age and identified individual and environmental factors that shape changes in HPA axis functioning over time. Participants were 167 mother–infant dyads drawn from a larger longitudinal study, recruited based on maternal history of being maltreated during childhood. Salivary cortisol levels were assessed before and after age‐appropriate psychosocial stressors when infants were 7 and 16 months old. Maternal observed parenting and maternal reports of infant and environmental characteristics were obtained at 7 months and evaluated as predictors of changes in infant baseline cortisol and reactivity from 7 to 16 months. Results revealed that infants did not show a cortisol response at 7 months, but reactivity to psychosocial stress emerged by 16 months. Individual differences in cortisol baseline and reactivity levels over time were related to infant sex and maternal overcontrolling behaviors, underscoring the malleable and socially informed nature of early HPA axis functioning. Findings can inform prevention and intervention efforts to promote healthy stress regulation during infancy. © 2015Wiley Periodicals, Inc. Dev Psychobiol 57: 356–364, 2015.
An enhanced home cage modulates hypothalamic CRH‐ir Labeling in juvenile rats, with and without sub‐threshold febrile convulsions
Authors: Korgan Austin C. , Vonkeman Janeske , Esser Michael J. , Perrot Tara S.
Published: March 2015

Pre and postnatal environments can have a profound impact on offspring development. This is especially true when considering the origin of neurological diseases, including epilepsy, a relatively common and chronic neurological condition, affecting 1–2% of the population. Previously, we have used maternal stress and an enhanced home cage (EHC) in an effort to identify potential factors in the early environment that may increase the risk for experiencing seizures. First, pregnant Long‐Evans rats were exposed to a predator stress (PS). Then, at birth, litters were divided into standard cage (SC) and EHC groups until postnatal Day 14 (PD14) when a model of febrile convulsions was used to determine convulsion susceptibility of the various groups. Twenty‐four hours later, pup brains were processed for immunohistochemical detection of corticotrophic releasing hormone (CRH) in the paraventricular nucleus of the hypothalamus. Analysis of CRH immunoreactive (‐ir) patterns revealed a buffering of CRH‐ir in EHC reared offspring. Further, experiencing convulsions led to decreased CRH‐ir. Our results support the concept that postnatal environmental influences affect neonatal programming and neurodevelopment of processes that could underlie seizure susceptibility, and that these effects can be modulated by EHC conditions. © 2015 Wiley Periodicals, Inc. Dev Psychobiol 57: 374–381, 2015.
Prox1 identifies proliferating neuroblasts and nascent neurons during neurogenesis in sympathetic ganglia
Authors: Holzmann Julia , Hennchen Melanie , Rohrer Hermann
Published: March 2015

Neurogenesis in embryonic sympathetic ganglia involves neuroblasts that resume proliferation following neuronal differentiation. As cell cycle exit is not associated with neuronal differentiation, the identity of proliferating neuroblasts is incompletely understood. Here, we use sympathetic ganglia of chick embryos to define the timing of neurogenesis and neuroblast identity focusing on the expression and function of the transcription factor Prox1. We show that a large fraction of neuroblasts has initially withdrawn from the cell cycle at embryonic day 3 (E3), which is reflected by a high proportion of p27+/Islet1+ neuroblasts (63%) and low numbers of EdU+/Islet1+ cells (12%). The proportion of proliferating Islet1+ neuroblasts, identified by EdU pulse labeling and by the absence of the postmitotic marker p27 increases to reach maximal levels at E5, when virtually all neuroblasts are in the cell cycle (95%). Subsequently, the proportion of EdU‐labeled and p27− neuroblasts is reduced to reach low levels at E11. Interestingly, the expression of the transcription factor Prox1 is restricted to the neuronal lineage, that is, Sox10+/Phox2b+ neuron progenitors, proliferating p27−/Islet1+ neuroblasts and nascent neurons but is rapidly lost in postmitotic neurons. In vitro and in vivo knockdown and overexpression experiments demonstrate effects of Prox1 in the support of neuroblast proliferation and survival. Taken together, these results define the neurogenesis period in the chick paravertebral sympathetic ganglia including an initial cell cycle withdrawal and identify Prox1 as a marker and regulator of proliferating sympathetic neuroblasts. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 75: 1352–1367, 2015
Fabrication of Magnetic Microactuators for Cytology Brush Built into Capsule Endoscope
Authors: YAMASHITA MAKI , HONDA TAKASHI
Published: March 2015

In this paper, we propose two kinds of magnetic microactuators for a cytology brush built into a capsule endoscope. One is a moving‐magnet linear actuator, in which the rotational oscillation of a permanent magnet is converted into linear movement through friction. The other is a rotating‐magnet actuator with a flexible push‐pull wire. Both actuators can be driven by an external magnetic field and can rub the brush back and forth. As in operational testing, we successfully pushed and pulled the brush back and forth along the surface of raw meat. We have also added a new angular positioning function to the capsule by using a DC magnetic field perpendicular to the magnetic field for rubbing the brush.
Estimation of Driver's Intention to Stop or Pass Through at Yellow Traffic Signal
Authors: MABUCHI RYUKI , YAMADA KEIICHI
Published: March 2015

At signalized intersections, a driver is forced to decide whether to stop or pass through when the signal turns yellow from green. It has been pointed out that this dilemma sometimes leads to accidents at intersections. This paper proposes two methods based on vehicle behavior for predicting whether a driver approaching a signalized intersection decides to stop or pass through the intersection when the signal turns yellow, in order to support the drivers' decision‐making to prevent accidents at and near intersections. The first method predicts whether a driver will decide to stop when the signal turns yellow, based on the idea that whether a driver decides to stop should depend on the situation and the vehicle behavior at the moment the signal turns yellow. The second method estimates whether a driver has decided to stop, in other words, whether the driver has the intention to stop, based on the idea that the driver's intention will appear in the vehicle behavior when the driver has decided to stop at the intersection. This method can detect the driver's oversight or neglect of traffic signals on the way to the intersection. The effectiveness of these two methods is demonstrated with experiments using real‐world data.
Arginase 1 activity worsens lung‐protective immunity against Streptococcus pneumoniae infection
Authors: Knippenberg Sarah , Brumshagen Christina , Aschenbrenner Franziska , Welte Tobias , Maus Ulrich A.
Published: March 2015

Type 2 helper cell (Th2) dominated chronic lung diseases such as asthma are characterized by an increased risk for bacterial lung infections. However, the underlying mechanisms are poorly defined. Arginase 1 (Arg1) has been suggested to play an important role in the pathophysiology of asthma, and is rapidly induced in lung macrophages by Th2 cytokines, thereby limiting macrophage‐derived antimicrobial nitric oxide (NO) production. Here we examined the effect of Th2 cytokine induced upregulation or lung myeloid cell specific conditional knockdown of Arg1 on lung resistance against Streptococcus pneumoniae (Spn) in mice. Lung macrophages responded with a profound induction of Arg1 mRNA and protein to treatment with IL‐13 both in vitro and in vivo. IL‐13‐induced Arg1 activity in the lungs of mice led to significantly attenuated lung‐protective immunity against Spn, while conditional Arg1 knockdown had no effect on lung‐protective immunity against Spn. Collectively, the data show that Th2 cytokine induced increased Arg1 activity worsens lung‐protective immunity against Spn, and interventions to block Th2 cytokine induced lung Arg1 activity may thus be a novel immunomodulatory strategy to lower the risk of bacterial infections in asthmatic patients.
Retention of the Cluster Core Structure during Ligand Exchange Reactions of Carboxylato‐Substituted Metal Oxo Clusters
Authors: Kreutzer Johannes , Puchberger Michael , Artner Christine , Schubert Ulrich
Published: March 2015

The exchange of the carboxylato ligands of Zr4O2(methacrylato)12 in reactions with carboxylic acids proceeds with retention of the composition and structure of the cluster core. This was concluded from exchange/re‐exchange experiments and from comparison of the IR bands of the cluster core of the original and ligand‐exchanged clusters. The IR bands were assigned on the basis of DFT calculations. Scrambling reactions between two Zr4O2(OOCR)12 clusters with different carboxylato ligands are a new way to prepare mixed‐ligand oxo clusters.
Accessible Syntheses of Late Transition Metal (Pre)Catalysts Bearing N‐Heterocyclic Carbene Ligands
Authors: Nelson David J.
Published: March 2015

This microreview details and discusses some selected examples of the accessible syntheses of useful complexes bearing N‐heterocyclic carbenes (NHCs). The term “accessible”, as used here, is defined as a synthetic route that does not require the isolation of the free NHC. These routes typically rely on either the generation of low equilibrium concentrations of the free NHC, which is then trapped by a metal centre, the deprotonation of the azolium salt by a suitable ligand or the activation of the C–H bond. These approaches can help to overcome a key weakness of NHCs in that they must be handled under stringently inert conditions. Studies of complexes based on metal centres from groups 8–11 are presented and discussed.
Electrochemical Immunosensor for the Determination of Total Ghrelin Hormone in Saliva
Authors: Martínez‐García Gonzalo , Serafín Verónica , Agüí Lourdes , Yáñez‐Sedeño Paloma , Pingarrón José M.
Published: March 2015

An electrochemical immunosensor for ghrelin (GHRL) determination in saliva is reported. Anti‐GHRL was immobilized onto Protein G‐magnetic beads and a competitive immunoassay involving biotinylated GHRL and alkaline phosphatase‐streptavidin was implemented. Once conjugate was magnetically captured on a screen‐printed carbon electrode, GHRL quantization was accomplished by DPV of 1‐naphtol formed upon addition of 1‐naphtyl phosphate. A linear range between 10−3 and 103 ng/mL GHRL, and a LOD of 7 pg/mL, much smaller than those from commercial ELISA kits, were found. The usefulness of the immunosensor was demonstrated by analyzing human saliva spiked with GHRL at 0.01, 0.1, 1 and 10 ng/mL.
Chitosan Based Diamond Paste Stochastic Microsensors Modified with Gold Nanoparticles Detect Hepatitis C Virus Core Antigen
Authors: Moldoveanu Iuliana , Stefan‐van Staden Raluca‐Ioana , Frederick van Staden Jacobus
Published: March 2015

Three types of chitosan (chitosan I (n=371–744), chitosan II (n=682–930), and chitosan III (n=868–1365)) as well as gold nanoparticles (10 nm diameter) were used to modify diamond paste for the design of new stochastic microsensors. Hepatitis C virus core antigen was used as model analyte to prove the stochastic behavior of the proposed microsensors. The microsensors cover a linear range of concentration between 40 fg/mL and 4 ng/mL. The highest sensitivity (1.38×105 s−1/mg/mL) and the lower limit of determination (40 fg/mL) were obtained for chitosan III based microsensor. The hepatitis C virus core antigen was assayed from whole blood samples with recoveries higher than 98.00 %.
Rock‐protecting seaweed? Experimental evidence of bioprotection in the intertidal zone
Authors: Gowell Matthew R. , Coombes Martin A. , Viles Heather A.
Published: March 2015

Biogeomorphological processes are an important component of dynamic intertidal systems. On rocky shores, the direct contribution of microorganisms, plants and animals to weathering and erosion is well known. There is also increasing evidence that organisms can alter rock breakdown indirectly, by moderating temperature and moisture regimes at the rock–air interface. These influences have been purported to represent mechanisms of bioprotection, by buffering microclimatic fluctuations associated with weathering processes such as wetting and drying and salt crystallization. However, virtually nothing has been done to test whether microclimatic buffering translates to differences in actual rock breakdown rates.

Here we report a preliminary laboratory experiment to assess how an artificial canopy (chosen to represent seaweed) affects mechanical rock breakdown. Using a simplified and accelerated thermal regime based on field data from a rocky shore platform in southern England, UK, we find that breakdown (mineral debris release) of mudstone covered with a canopy is reduced by as much as 79% relative to bare rock after around 100 thermal cycles. Reduction in rock surface hardness (measured using an Equotip device) was also greater for bare rock (17%) compared to covered rock (10%) over this period. Measurements of salt crystal formation indicate that the mechanism driving these differences was a reduction in the frequency of crystallization events, via moisture retention and shading of the rock surface. Copyright © 2015 John Wiley & Sons, Ltd.
New formula for calculating time to ignition of semi‐infinite solids
Authors: Wickström Ulf
Published: March 2015

An analytical closed form formula is presented for explicitly calculating time to reach ignition temperature of semi‐infinite solids exposed to constant incident radiation and gas temperature as for example in the cone calorimeter. The non‐linear boundary condition due to the emitted radiation from the surface being proportional to the surface temperature raised to the fourth power according to the Stephan–Boltzmann law is accurately considered. The formula works for a wide range of the parameter values like the thermal inertia of the solid, the emissivity of the exposed surface and the convective heat transfer coefficient. They are all assumed constant. The new formula contains a single constant coefficient, which has been derived by comparing results obtained by accurate numerical finite element simulations using two different codes, comsol and TASEF, as well as calculations based on a Duhamel superposition scheme. Thus, the formula can be classified as semi‐empirical. It offers a simple approximate solution of a non‐linear problem that requires cumbersome numerical calculation methods to obtain more exact results. Any exact analytical solution is not available. The new method is carefully verified by comparisons with numerical solutions. However, as it is an analysis of well‐defined theoretical methods, any validation and comparisons with test data are not required and has therefore not been made.In comparison with other similar approximation formulas found in the literature, the accuracy as well as simplicity of applying the new formula is outstanding. Copyright © 2015 John Wiley & Sons, Ltd.
Lending to Parents and Insuring Children: Is There a Role for Microcredit in Complementing Health Insurance in Rural China?
Authors: You Jing
Published: March 2015

This paper assesses the causal impact on child health of borrowing formal microcredit for Chinese rural households by exploiting a panel dataset (2000 and 2004) in a poor northwest province. Endogenous borrowing is controlled for in a dynamic regression‐discontinuity design creating a quasi‐experimental environment for causal inferences. There is causal relationship running from formal microcredit to improved child health in the short term, while past borrowing behaviour has no protracted impact on subsequent child health outcomes. Moreover, formal microcredit appears to be a complement to health insurance in improving child health through two mechanisms—it enhances affordability for out‐of‐pocket health care expenditure and helps buffer consumption against adverse health shocks and financial risk incurred by current health insurance arrangements. Government efforts in expanding health insurance for rural households would be more likely to achieve its optimal goals of improving child health outcomes if combined with sufficient access to formal microcredit. Copyright © 2015 John Wiley & Sons, Ltd.