bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxidation of quinolones with peracids (an in situ EPR study)
Authors: Staško Andrej , Milata Viktor , Barbieriková Zuzana , Brezová Vlasta
Published: November 2013

4‐Oxoquinoline derivatives (quinolones) represent heterocyclic compounds with a variety of biological activities, along with interesting chemical reactivity. The quinolone derivatives possessing secondary amino hydrogen at the nitrogen of the enaminone system are oxidized with 3‐chloroperbenzoic acid to nitroxide radicals in the primary step while maintaining their 4‐pyridone ring. Otherwise, N‐methyl substituted quinolones also form nitroxide radicals coupled with the opening of the 4‐pyridone ring in a gradual oxidation of the methyl group via the nitrone–nitroxide spin‐adduct cycle. This was confirmed in an analogous oxidation using N,N‐dimethylaniline as a model compound. N‐Ethyl quinolones in contrast to its N‐methyl analog form only one nitroxide radical without a further degradation. Copyright © 2013 John Wiley & Sons, Ltd.
Funktionelle Lipidmembranen in der Chiptechnik
Authors: Steinem Claudia
Published: November 2013

Jede Substanz, die das Innere einer Zelle erreichen soll, muss eine Barriere überwinden. Diese ist nur wenige Nanometer dick, aber aus tausenden von verschiedenen Molekülen zusammengesetzt: die Membran. Wie funktioniert das komplexe Zusammenspiel ihrer Komponenten?
Photoredoxkatalyse
Authors: Tamke Sergej , Paradies Jan
Published: November 2013

In den letzten fünf Jahren hat sich die Photoredoxkatalyse von einer Laborkuriosität zu einer verlässlichen Synthesemethode gemausert.
Alles aus einer Hand oder von allem das Beste?
Authors: Landgraf Evelyn
Published: November 2013

Die heterogene Planungswelt der Prozessindustrie fordert heterogene Lösungen: Integrated Engineering mit nur einem System geht an der Realität vorbei. Revisionssichere Schnittstellensoftware verbindet unterschiedliche Softwaresysteme.
Amine in Getränken und Fleisch
Authors: Giegold Sascha
Published: November 2013

Der Gehalt an biogenen Aminen wie Histamin, Cadaverin oder Tyramin in einem Lebensmittel liefert Hinweise darauf, ob es verdorben ist. Automatisierte Vorsäulenderivatisierung beschleunigt die flüssigchromatographische Bestimmung dieser toxischen Substanzen.
Conjugated block copolymers via functionalized initiators and click chemistry
Authors: Smith Kendall A. , Pickel Deanna L. , Yager Kevin , Kisslinger Kim , Verduzco Rafael
Published: November 2013

Conjugated block copolymers are potentially useful for organic electronic applications and the study of interfacial charge and energy transfer processes; yet few synthetic methods are available to prepare polymers with well‐defined conjugated blocks. Here, we report the synthesis and thin film morphology of a series of conjugated poly(3‐hexylthiophene)‐block‐poly(9,9‐dioctylfluorene) (P3HT‐b‐PF) and poly(3‐dodecylthiophene)‐block‐poly(9,9‐dioctylfluorene) (P3DDT‐b‐PF) block copolymers prepared by functional external initiators and click chemistry. Functional group control is quantified by proton nuclear magnetic resonance spectroscopy, size‐exclusion chromatography, and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. The thin film morphology of the resulting all‐conjugated block copolymers is analyzed by a combination of grazing‐incidence X‐ray scattering, atomic force microscopy, and transmission electron microscopy. Crystallization of the P3HT or P3DDT blocks is present in thin films for all materials studied, and P3DDT‐b‐PF films exhibit significant PF/P3DDT co‐crystallization. Processing conditions are found to impact thin film crystallinity and orientation of the π–π stacking direction of polymer crystallites. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 154–163
Navigation‐aided visualization of lumbosacral nerves for anterior sacroiliac plate fixation: a case report
Authors: Takao Masaki , Nishii Takashi , Sakai Takashi , Sugano Nobuhiko
Published: November 2013

Background

Anterior sacroiliac joint plate fixation for unstable pelvic ring fractures avoids soft tissue problems in the buttocks; however, the lumbosacral nerves lie in close proximity to the sacroiliac joint and may be injured during the procedure.

Methods

A 49 year‐old woman with a type C pelvic ring fracture was treated with an anterior sacroiliac plate using a computed tomography (CT)–three‐dimensional (3D)‐fluoroscopy matching navigation system, which visualized the lumbosacral nerves as well as the iliac and sacral bones. We used a flat panel detector 3D C‐arm, which made it possible to superimpose our preoperative CT‐based plan on the intra‐operative 3D‐fluoroscopic images.

Results

No postoperative complications were noted.

Conclusions

Intra‐operative lumbosacral nerve visualization using computer navigation was useful to recognize the 'at‐risk' area for nerve injury during anterior sacroiliac plate fixation. Copyright © 2013 John Wiley & Sons, Ltd.
The Neurobiological Basis of the Distress Thermometer: A PET Study in Cancer Patients
Authors: Castelli L. , Tonello D. , D'Agata F. , Caroppo P. , Baudino B. , Zotta M. , Cauda S. , Pinessi L. , Mortara P. , Grassi L. , Bisi G. , Torta R.
Published: November 2013

The objective of this study was to investigate the possible associations between the Distress Thermometer (DT) scores and the brain metabolism of structures involved in stress response. Twenty‐one cancer patients were assessed using the DT, Problem Checklist and Hospital Anxiety and Depression Scale (HADS). The psychological measures were correlated with [18 F]PET‐FDG brain glucose metabolism. Multiple and linear regression and binary logistic regression were run to analyse data.

The DT and HADS scores illustrated that 48% of patients were distressed, 19% were depressed and48% were anxious. Results showed that some subcortical areas activity, such as part of midbrain and of hypothalamus, was correlated with the DT scores. The Problem Checklist scores correlated with the activity of the same areas and included more regions in the limbic forebrain and brainstem.

Compared with the DT and Problem Checklist, HADS‐Depression scores showed a more extensive pattern of correlation with brain activity, including limbic and cortical areas.

The results highlighted that the DT scores correlated with the activity of brain areas typically involved in stress response. Indeed, hypothalamus metabolism was found to be the best predictor of distressed patients. Copyright © 2013 John Wiley & Sons, Ltd.
Robustness‐based performance assessment of a prestressed concrete bridge
Authors: Podroužek Jan , Strauss Alfred , Bergmeister Konrad
Published: November 2013

Life‐cycle civil engineering addresses, among other things, the growing number of deteriorating bridges and the associated economic challenges. As a consequence, government bodies, infrastructure and bridge owners as well as industry request objective and rational performance indicators for classification and intervention planning in structural engineering. This paper focuses on a methodology for analysing the damage‐based robustness margins of bridge systems under traffic loading. In particular, a series of emergent deterioration‐based damage scenarios are compared with the actual or virgin state in terms of loadbearing capacity and serviceability. Non‐linear finite element analysis based on a detailed 3D model has a high potential for capturing the available bridge capacity for different degradation phenomena and levels, serving as an input for further reliability‐based performance indicators. Notwithstanding, costs associated with fully probabilistic assessment measures are still prohibitive despite technological advances and new methods of reducing the sample size in Monte Carlo computations. In addition, considering the large uncertainties and imprecision involved, it is imperative that probabilistic schemes are preferred over deterministic assessments.

The objective of this article is to present strategies for robustness‐based performance assessment using non‐linear modelling and to discuss relevant reliability‐based quantities and performance indicators in relation to structural damage using the example of specific degradation events in an existing prestressed box girder bridge. Furthermore, some strategies are developed on the basis of the new approach for general complex engineering structures.
Experimental, analytical and numerical analysis of the pullout behaviour of steel fibres considering different fibre types, inclinations and concrete strengths
Authors: Breitenbücher Rolf , Meschke Günther , Song Fanbing , Zhan Yijian
Published: November 2013

The pullout behaviour of single steel fibres embedded in a concrete matrix is investigated for various configurations of fibre types and embedment lengths and angles by means of laboratory tests and analytical models. Laboratory tests for fibre pullout are performed to investigate the fibre‐matrix bond mechanisms. Parameters influencing the fibre pullout response, such as fibre shape, fibre tensile strength, concrete strength and fibre inclination angle are systematically studied. The effects of these parameters on the pullout force versus displacement relationship, fibre efficiency and fibre/matrix failure response are analysed based on the experimental results. For the analytical modelling of the fibre pullout behaviour of straight fibres, an interface law is proposed for the frictional behaviour between fibre and matrix. In the case of inclined fibres, the plastic deformation of the fibre and the local damage to the concrete are also considered. For hooked‐end fibres, the anchorage effect due to the hook is analysed. Combining these sub‐models allows the pullout response of single fibres embedded in a concrete matrix to be predicted. In addition, numerical simulations of pullout tests are performed to obtain insights into the local fibre‐concrete interactions and to provide supporting information for the analytical modelling. The models are successfully validated with the experimental results.
When Erving Goffman Was a Boy: The Formative Years of a Sociological Giant
Authors: Cavan Sherri
Published: November 2013

This exploratory paper addresses the intersection of character and social structure by looking at the childhood and youth of Erving Goffman. Drawing from historical and contemporary documents, I reconstruct the social world of Canada between WWI and WWII and Goffman's place in it, identify Goffman's social position as an outsider, and document his early familiarity with dramaturgy. The argument is made that Goffman's formative years illuminate his interest in stigma, showing how stigmatizing circumstances can discredit claims to identity, and suggesting how impression management helps mitigate the discrepancy between a person's real life circumstances and prevailing cultural ideas.
Cougar population status and range expansion in Alberta during 1991–2010
Authors: Knopff Kyle H. , Webb Nathan F. , Boyce Mark S.
Published: November 2013

In Alberta, Canada, number of cougar (Puma concolor) mortalities caused by humans has increased rapidly over the past 2 decades. Management agencies sometimes use human‐caused mortalities as an index of cougar population trend, which would indicate an increasing cougar population in Alberta, but mortalities may be decoupled from cougar numbers. Some authors suggest that higher human‐caused cougar mortalities (primarily due to sport hunting) are causing cougar populations in North America to decline. We used the distribution of human‐caused cougar mortalities in Alberta to evaluate change in cougar populations during 1991–2010, a period over which human‐caused cougar mortality increased rapidly. We provide evidence that cougars have expanded their range in northern and eastern Alberta in tandem with increasing sport hunting and other sources of human‐caused mortality. © 2013 The Wildlife Society.
Molybdenum(0) and Tungsten(0) Complexes with P,S and P,Se Monooxidized Bis(phosphanyl)amine Ligands
Authors: Al‐Masri Harbi Tomah , Moussa Ziad , Fazal Atif , Fettouhi Mohammed
Published: November 2013

Reactions of monooxidized thioyl and selenoyl bis(phosphanyl)amine ligands C10H7‐1‐N(P(E)Ph2)(PPh2) [E = S (1), Se (2)] with Mo(CO)4(pip)2 and W(CO)4(cod) afforded the complexes [M(CO)4{1‐κ2P,S}] [M = Mo (3), W (4)] and [M(CO)4{2‐κ2P,Se}] [M = Mo (5), W (6)]. Complexes 3–6 were characterized by multinuclear NMR (1H, 13C, 31P, and 77Se NMR) and IR spectroscopy. Crystal‐structure determinations were carried out on 3, 5, and 6, which represent the first examples of structurally characterized complexes of such ligands with group‐6 metal carbonyls.
The Effects of the Organic Groups Attached at the Silicone Atoms of the Organosilane‐Based Gemini Nonionic Surfactants on Their Surface Activities
Authors: Xing Fenglan , Gao Yueyue , Xu Qun , Li Xu , Wang Liyan , Meng Jie , Wang Pinglang
Published: November 2013

A novel trisiloxane gemini nonionic surfactant was synthesized by the reaction of 3‐(diethoxy(methyl)silyl)propan‐1‐amine with hexamethyldisiloxane to get 3‐(trisiloxane)propan‐1‐amine, which was further reacted with glutaroyl dichloride to form the surfactant molecule, N1,N5‐bis(3‐(trisiloxane)propyl)glutaramide (3). Some related compounds were also prepared, including N1,N5‐bis (3‐(trimethoxysilyl)propyl) glutaramide (1), and N1,N5‐bis(3‐(diethoxy(methyl)silyl)propyl)glutaramide (2). All prepared compounds were analyzed by IR, 1H‐NMR and 13C‐NMR to confirm their structures. Their interfacial activities, including surface tension and wetting ability, were measured. These surface activities were compared each other and a discussion was carried out on how the organic groups attached on the silicone atoms affect their surface tension and wetting ability. To explain the superior surface activities of the molecules 3, a hypothesis was proposed about a cyclic hydrophobic core area that could be formed by the two hydrophobic chains and the linker of the gemini molecule due to the dispersion force (Van der Waals force) between the two trisiloxane moieties, which close the hydrophobic cycle inside the molecule.
Live‐cell single‐molecule imaging reveals clathrin and caveolin‐1 dependent docking of SMAD4 at the cell membrane
Authors: Yang Yong , Wolfram Joy , Shen Jianliang , Zhao Yuliang , Fang Xiaohong , Shen Haifa , Ferrari Mauro
Published: November 2013

Transforming growth factor β (TGF‐β) signaling is important for many biological processes. Although the sequential events of this cascade are known, the dynamics remain speculative. Here, live‐cell single‐molecule total internal reflection fluorescence microscopy was used to monitor the dynamics of SMAD4, a TGF‐β downstream effector, in MDA‐MB‐231 breast cancer cells. Contrary to previous belief, SMAD4 was detectable at the cytoplasmic membrane, displaying two subpopulations with different membrane docking behaviors. These subpopulations were regulated by clathrin and caveolin‐1, and had opposing roles in the nuclear shuttling of SMAD4 and the subsequent transcriptional regulation of genes associated with cell migration. The notion that membrane‐docking behaviors of downstream molecules could predict the cellular response to growth factors may revolutionize the way we view cell signaling.
Production of prone‐to‐aggregate proteins
Authors: Lebendiker Mario , Danieli Tsafi
Published: November 2013

Expression of recombinant proteins in Escherichia coli (E. coli) remains the most popular and cost‐effective method for producing proteins in basic research and for pharmaceutical applications. Despite accumulating experience and methodologies developed over the years, production of recombinant proteins prone to aggregate in E. coli‐based systems poses a major challenge in most research applications. The challenge of manufacturing these proteins for pharmaceutical applications is even greater. This review will discuss effective methods to reduce and even prevent the formation of aggregates in the course of recombinant protein production. We will focus on important steps along the production path, which include cloning, expression, purification, concentration, and storage.
A generalized mathematical model of geostrophic adjustment and frontogenesis: uniform potential vorticity
Authors: Shakespeare Callum J. , Taylor J. R.
Published: November 2013

Fronts, or regions with strong horizontal density gradients, are ubiquitous and dynamically important features in the ocean and atmosphere. In the atmosphere, fronts are associated with some of the most severe weather events, while in the ocean, fronts are associated with enhanced turbulence, water mass transformation and biological activity. Here, we examine the dynamics involved in the formation of fronts, or frontogenesis, in detail using a generalized mathematical framework. This extends previous work which has generally revolved around two limiting cases: fronts generated through forcing due to a convergent large-scale flow, and fronts generated spontaneously during the geostrophic adjustment of an initially unbalanced flow. Here, we introduce a new generalized momentum coordinate to simultaneously describe forced and spontaneous frontogenesis. The nonlinear, inviscid, Boussinesq, hydrostatic governing equations for uniform PV flow are solved for arbitrary Rossby and Froude number. The solution is then examined in three distinct cases. Firstly, for a zero potential vorticity (PV) flow bounded by rigid lids, a general solution is derived for the transient response of the fluid to an arbitrary initial mass imbalance and deformation field. The deformation frontogenesis solution of Hoskins & Bretherton (J. Atmos. Sci., vol. 29, 1972, pp. 11–37) and the mass imbalance solution of Blumen (J. Phys. Oceanogr., vol. 30, 2000, pp. 31–39) emerge as two limits of this general solution. Secondly, the problem of geostrophic adjustment of an initial mass imbalance (no deformation field) is considered for uniform PV flow bounded by rigid lids. The general solution is derived, composed of an adjusted state and a transient component describing the propagation of inertia–gravity waves. The criteria for the occurrence of a frontal discontinuity is determined in terms of the Rossby and Froude numbers. The uniform PV solution reduces identically to the zero PV solution of Blumen in the limit of vanishing background stratification. Thirdly, we examine the more general case of uniform PV flow with a deformation field and either balanced or unbalanced initial conditions. In this case the solution is composed of a time-varying mean state – matching the Hoskins & Bretherton solution in the limit of small strain – and an inertia gravity wave field, the dynamics of which are examined in detail. Our analysis provides a unifying framework capable of describing frontal formation and geostrophic adjustment in a wide variety of settings.
Array CGH as a first-tier test for neonates with congenital heart disease
Authors: Bachman Kristine K. , DeWard Stephanie J. , Chrysostomou Constantinos , Munoz Ricardo , Madan-Khetarpal Suneeta
Published: November 2013

Objective

Efficient diagnosis of an underlying genetic aetiology in a patient with congenital heart disease is essential to optimising clinical care. Copy number variants are one aetiology of congenital heart disease; the majority are identifiable by targeted fluorescence in situ hybridisation or array comparative genomic hybridisation, not by classical cytogenetic analysis. This study assessed the utility of array comparative genomic hybridisation as a first-tier diagnostic test for neonates with congenital heart disease.

Study design

A prospective chart review of neonates with congenital heart disease in the Cardiac Intensive Care Unit at Children’s Hospital of Pittsburgh of UPMC was performed. Patients were tested by array comparative genomic hybridisation and classical cytogenetic analysis simultaneously. Data collected included all chromosome abnormalities detected, physical examination findings, and imaging results. McNemar’s test was used to compare detection of array comparative genomic hybridisation and classical cytogenetic analysis.

Results

Of 45 patients, three (6.7%) had an abnormality detected by classical cytogenetic analysis and an additional 10 (22.2%) had a copy number variant detected by array comparative genomic hybridisation, highlighting an increased detection rate (p=0.008). Several of these copy number variants had unclear clinical significance, requiring additional investigation. The prevalence of dysmorphology and/or comorbidity in this population was 72%. Identification of dysmorphic features was greater when assessed by a geneticist than by providers of different subspecialties.

Conclusions

Array comparative genomic hybridisation has significant clinical utility as a first-tier test in this population, but it carries the potential for incidental findings and results of uncertain clinical significance. Collaboration between cardiologists and medical geneticists is essential to providing optimal clinical care.
Environmental influences on fruit and vegetable intake: results from a path analytic model
Authors: Liese Angela D , Bell Bethany A , Barnes Timothy L , Colabianchi Natalie , Hibbert James D , Blake Christine E , Freedman Darcy A
Published: November 2013

Objective

Fruit and vegetable (F&V) intake is influenced by behavioural and environmental factors, but these have rarely been assessed simultaneously. We aimed to quantify the relative influence of supermarket availability, perceptions of the food environment and shopping behaviour on F&V intake.

Design

A cross-sectional study.

Setting

Eight counties in South Carolina, USA, with verified locations of all supermarkets.

Subjects

A telephone survey of 831 household food shoppers ascertained F&V intake with a seventeen-item screener, primary food store location, shopping frequency and perceptions of healthy food availability, and supermarket availability was calculated with a geographic information system. Path analysis was conducted. We report standardized beta coefficients on paths significant at the 0·05 level.

Results

Frequency of grocery shopping at primary food store (β = 0·11) was the only factor exerting an independent, statistically significant direct effect on F&V intake. Supermarket availability was significantly associated with distance to utilized food store (β = −0·24) and shopping frequency (β = 0·10). Increased supermarket availability was significantly and positively related to perceived healthy food availability in the neighbourhood (β = 0·18) and ease of shopping access (β = 0·09). Collectively considering all model paths linked to perceived availability of healthy foods, this measure was the only other factor to have a significant total effect on F&V intake.

Conclusions

While the majority of the literature to date has suggested an independent and important role of supermarket availability for F&V intake, our study found only indirect effects of supermarket availability and suggests that food shopping frequency and perceptions of healthy food availability are two integral components of a network of influences on F&V intake.
Adherence to the Dutch Guidelines for a Healthy Diet and cancer risk in the European Prospective Investigation into Cancer and Nutrition–Netherlands (EPIC-NL) cohort
Authors: Struijk Ellen A , May Anne M , Beulens Joline WJ , Fransen Heidi P , de Wit G Ardine , Boer Jolanda MA , Onland-Moret N Charlotte , Hoekstra Jeljer , van der Schouw Yvonne T , Bueno-de-Mesquita H Bas , Peeters Petra HM
Published: November 2013

Objective

To examine the association between adherence to the Dutch Guidelines for a Healthy Diet created by the Dutch Health Council in 2006 and overall and smoking-related cancer incidence.

Design

Prospective cohort study.

Setting

Adherence to the guidelines, which includes one recommendation on physical activity and nine on diet, was measured using an adapted version of the Dutch Healthy Diet (DHD) index. The score ranged from 0 to 90 with a higher score indicating greater adherence to the guidelines. We estimated the hazard ratios (HR) and 95 % confidence intervals for the association between the DHD index (in tertiles and per 20-point increment) at baseline and cancer incidence at follow-up.

Subjects

We studied 35 608 men and women aged 20–70 years recruited into the European Prospective Investigation into Cancer and Nutrition–Netherlands (EPIC-NL) study during 1993–1997.

Results

After an average follow-up of 12·7 years, 3027 cancer cases were documented. We found no significant association between the DHD index (tertile 3v. tertile 1) and overall (HR = 0·97; 95 % CI 0·88, 1·07) and smoking-related cancer incidence (HR = 0·89; 95 % CI 0·76, 1·06) after adjustment for relevant confounders. Excluding the components physical activity or alcohol from the score did not change the results. None of the individual components of the DHD index was significantly associated with cancer incidence.

Conclusions

In the present study, participants with a high adherence to the Dutch Guidelines for a Healthy Diet were not at lower risk of overall or smoking-related cancer. This does not exclude that other components not included in the DHD index may be associated with overall cancer risk.
The importance of stakeholder engagement in the corporate responsibility to respect human rights
Authors: Dubach Barbara , Machado Maria Teresa
Published: November 2013

Over the past forty years, there has been a steady rise in the expectation for companies to operate as responsible citizens. Today companies have at their disposal a variety of initiatives, and new levels of accountability have been reached with the advancement of international standards on, among others, corporate responsibility to respect human rights. Against this background, this article provides an overview of the most important guiding tools available on this subject and on how to promote peace and stability when operating in conflict-affected or high-risk areas. The article argues that ongoing stakeholder engagement is a key success factor in meeting the responsibility to respect human rights and that it has to be an integral part of a company's strategy, especially when operating in conflict-affected countries.
SMTP-7, a Novel Small-Molecule Thrombolytic for Ischemic Stroke: A Study in Rodents and Primates
Authors: Sawada Hironobu , Nishimura Naoko , Suzuki Eriko , Zhuang Jie , Hasegawa Keiko , Takamatsu Hiroyuki , Honda Kazuo , Hasumi Keiji
Published: November 2013

SMTP-7 ( Stachybotrys microspora triprenyl phenol-7), a small molecule that promotes plasminogen activation through the modulation of plasminogen conformation, has excellent therapeutic activity against cerebral infarction in several rodent models. Detailed evaluations of SMTP-7 in a primate stroke model are needed for effective, safe drug development. Here we evaluated SMTP-7 in a monkey photochemical-induced thrombotic middle cerebral artery (MCA) occlusion model ( n=6), in which MCA occlusion was followed by recanalization/reocclusion. SMTP-7 (10 mg/kg, intravenous infusion) significantly increased the postinfusion MCA recanalization rate (32.5-fold, P=0.043) and ameliorated the post-24-h neurologic deficit (by 29%, P=0.02), cerebral infarct (by 46%, P=0.033), and cerebral hemorrhage (by 51%, P=0.013) compared with the vehicle control animals. In normal monkeys, SMTP-7 did not affect general physiologic or hemostatic variables, including coagulation and platelet parameters. Investigations in rodent models of transient and permanent focal cerebral ischemia, as well as arterial thrombosis and bleeding tests, suggest a role for SMTP-7's regulated profibrinolytic action and neuroprotective properties in the monkey MCA occlusion model. In conclusion, SMTP-7 is effective in treating thrombotic stroke in monkeys. SMTP-7 is thus a promising candidate for the development of alternative therapy for ischemic stroke.
Intracellular Acidification Alters Myogenic Responsiveness and Vasomotion of Mouse Middle Cerebral Arteries
Authors: Thomsen Axel BK , Kim Sukhan , Aalbaek Filip , Aalkjaer Christian , Boedtkjer Ebbe
Published: November 2013

Intracellular pH (pHi) in the vascular wall modulates agonist-induced vasocontractile and vasorelaxant responses in mesenteric arteries, whereas effects on myogenic tone have been unsettled. We studied the role of Na+,HCO3− cotransporter NBCn1 in mouse isolated middle cerebral arteries and the influence of pHi disturbances on myogenic tone. Na+,HCO3− cotransport was abolished in arteries from NBCn1 knockout mice and steady-state pHi ∼0.3 units reduced compared with wild-type mice. Myogenic tone development was low under control conditions but increased on treatment with the NO-synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME). This effect of L-NAME was smaller in arteries from NBCn1 knockout than wild-type mice. Myogenic tone with L-NAME present was significantly lower in arteries from NBCn1 knockout than wild-type mice and was abolished by rho-kinase inhibitor Y-27632. The arteries displayed vasomotion, and this rhythmic contractile pattern was also attenuated in arteries from NBCn1 knockout mice. No differences in membrane potential or intracellular [Ca2+] were seen between arteries from NBCn1 knockout and wild-type mice. We propose that NO production and rho-kinase-dependent Ca2+ sensitivity are reduced at low pHi in pressurized mouse middle cerebral arteries. This likely impedes the ability to adjust to changes in perfusion pressure and regulate cerebral blood flow.
Cerebrovascular Reactivity in the Brain White Matter: Magnitude, Temporal Characteristics, and Age Effects
Authors: Thomas Binu P , Liu Peiying , Park Denise C , van Osch Matthias JP , Lu Hanzhang
Published: November 2013

White matter (WM) comprises about half of the brain and its dysfunction is implicated in many brain disorders. While structural properties in healthy and diseased WM have been extensively studied, relatively little is known about the physiology underlying these structural characteristics. Recent advances in magnetic resonance (MR) technologies provided new opportunities to better understand perfusion and microvasculature in the WM. Here, we aim to evaluate vasodilatory capacity of the WM vasculature, which is thought to be important in tissue ischemia and autoregulation. Fifteen younger and fifteen older subjects performed a CO2 inhalation task while blood-oxygenation-level-dependent (BOLD) magnetic resonance imaging (MRI) images were continuously collected. The cerebrovascular reactivity (CVR) index showed that the value of CVR in the WM (0.03±0.002%/mm Hg) was positive, but was significantly lower than that in the gray matter (GM) (0.22±0.01%/mm Hg). More strikingly, the WM response showed a temporal delay of 19±3 seconds compared with GM, which was attributed to the longer time it takes for extravascular CO2 to change. With age, WM CVR response becomes greater and faster, which is opposite to the changes seen in the GM. These data suggest that characteristics of WM CVR are different from that of GM and caution should be used when interpreting pathologic WM CVR results.
The Retraction Penalty: Evidence from the Web of Science
Authors: Lu Susan Feng , Jin Ginger Zhe , Uzzi Brian , Jones Benjamin
Published: November 2013

Scientific articles are retracted at increasing rates, with the highest rates among top journals. Here we show that a single retraction triggers citation losses through an author's prior body of work. Compared to closely-matched control papers, citations fall by an average of 6.9% per year for each prior publication. These chain reactions are sustained on authors' papers (a) published up to a decade earlier and (b) connected within the authors' own citation network by up to 4 degrees of separation from the retracted publication. Importantly, however, citation losses among prior work disappear when authors self-report the error. Our analyses and results span the range of scientific disciplines.
Visual detection of amino acids by supramolecular gel collapse
Authors: He Ting , Li Kun , Wu Ming-Yu , Liao Ye-Xin , Yu Xiao-Qi
Published: November 2013

Several cholesterol-based low molecular weight gelators were synthesized, and their gelation abilities were investigated. These compounds could form gels in various organic solvents. Specifically, gel 1 collapsed selectively in the presence of Asp and Glu.
Core–shell, hollow-structured iridium–nickel nitride nanoparticles for the hydrogen evolution reaction
Authors: Kuttiyiel Kurian A. , Sasaki Kotaro , Chen Wei-Fu , Su Dong , Adzic Radoslav R.
Published: November 2013

A core–shell structured Ni nitride capped by an Ir shell enhances the HER activity compared to a Pt catalyst.
Cooperative modulation classification with data fusion for multipath fading channels
Authors: Markovic G.B. , Dukic M.L.
Published: November 2013

Data fusion methods are proposed for cooperative modulation classification by using multiple sensors in multipath fading channels. Performances of these methods are evaluated, and compared with those of the existing optimal decision fusion method, through Monte Carlo simulations for a realistic application scenario, and evident gains are confirmed.
Near‐threshold charge pump circuit using dual feedback loop
Authors: Jalalifar M. , Byun G.‐S.
Published: November 2013

A near‐threshold charge pump circuit suitable for a phase‐locked loop‐based frequency synthesiser is presented. The charge pump uses gate switches and dual feedback loops to achieve good up/down current matching characteristics in low‐voltage operation. The applied gate switches reduce the leakage current and the feedback loops provide a more stable operation. Post‐layout simulation results demonstrate that the proposed charge pump circuit consumes only 60 µW with a 0.5 V supply voltage. The charge pump circuit is implemented in a 0.13 µm CMOS process.
Application‐specific fine tuning of multi‐parameter patient monitors
Authors: Vaijeyanthi V. , Kumar C.S. , Ramachandran K.I. , Joy J.K , Kumar A.A.
Published: November 2013

Multi‐parameter patient monitors (MPMs) have become increasingly important in providing quality health care to patients. A high alarm accuracy (sensitivity) will need a lower threshold for alarm detection which will lead to lower no‐alarm accuracy (specificity) and vice‐versa. MPMs when used in an intensive care unit (ICU) need to have high sensitivity. However they need to have high specificity when used in in‐patient wards for regular health check‐ups. Proposed is a novel algorithm to trade‐off specificity for sensitivity and vice‐versa depending on the application. The proposed method is referred as detection error trade‐off, trade‐off specificity for better sensitivity and vice‐versa. The algorithm will help to extend the application of MPMs from ICUs to in‐patient wards and thus enhance the quality of health care. Experiments have been conducted with an MPM using the classification and regression tree algorithm. By using the proposed algorithm, an improvement of 10.18% in sensitivity was obtained by trading‐off 0.40% in specificity. Furthermore, the overall performance of the refined system is 1.15% better than the baseline system.
Determination of the inductance parameters for the decoupled d–q model of double‐star permanent‐magnet synchronous machines
Authors: Kallio Samuli , Karttunen Jussi , Peltoniemi Pasi , Silventoinen Pertti , Pyrhönen Olli
Published: November 2013

Analytical models are the key tools in the model‐based control design of electric drives. The inductances together with the stator resistance are the fundamental parameters of these models. In this study three methods to determine the inductances of the decoupled d–q model of double‐star permanent‐magnet (PM) synchronous machines are studied. These methods have commonly been used to determine the inductances of conventional three‐phase PM machines. Two of the evaluated methods are based on the phase‐variable inductance waveforms and flux linkages and are thus analysed with finite‐element analyses only. The third method, based on the analytical stator voltage equations, can be applied straightforwardly with the real drive system supplied with voltage‐source inverters (VSIs). This method requires only the knowledge of the rotor position and the existing current measurements of the VSIs that are used for the current control. Experimental results are provided to verify the applicability of the voltage‐equation‐based method to determine the inductances. On the average, the presented methods provide similar values, but also some discrepancies between the obtained values can be observed. The measured inductance parameters are validated using model‐based closed‐loop controllers.
New boost converter based on Sheppard–Taylor topology
Authors: Hua Chih‐Chiang , Chiang Hsi‐Chin , Chuang Chih‐Wei
Published: November 2013

This study presents a new boost converter based on Sheppard–Taylor topology for low‐power applications. The proposed converter is capable of regulating output voltage under wide range of input voltage or load variations. Compared with the Sheppard–Taylor converter, the converter can be implemented with fewer components. The main switches of converter are turned on with zero‐current‐switching, and the rectifier diodes are turned off with zero‐voltage‐switching. A small‐signal average model for the proposed converter is derived and transfer functions for the system output voltages are derived. The guidelines for the system design are provided. Finally, experimental results are given to confirm the system performance.
Analysis, design and digital implementation of a shunt active power filter with different schemes of reference current generation
Authors: Chauhan Siddharthsingh K. , Shah Mihir C. , Tiwari Ram Ratan , Tekwani P. N.
Published: November 2013

To reduce the harmonics injected by non‐linear loads, power quality improvement devices like shunt active power filters (SAPFs) are commonly employed. This study presents a digital signal processor (DSP) TMS320LF2407A based hardware implementation of current error space phasor‐based hysteresis controller for SAPF. The proposed controller‐based SAPF allows precise compensation of harmonic currents. Design considerations for practical implementation of the proposed space phasor‐based current error hysteresis controller for SAPF are explained here. Performance analysis of space phasor‐based current error hysteresis controller for SAPF is explained in the study. The controller's self‐adaptive nature is studied for different logics of necessary sector changes. Here, the versatile nature of the controller is proved by analysing its performance for different reference compensating current generation methods. The proposed controller works on the principle of switching voltage vectors adjacent to the desired output voltage vector of SAPF (voltage vector at the point of common coupling). This strategy helps in restricting the current error within the desired hexagonal boundary. A comparative study of DSP‐based implementation for two different schemes of reference compensating currents generation is presented in this study. Instantaneous reactive power theory and Fryze current computation methods are chosen for this comparative study. Experimental results of reference compensating currents generated by different strategies using DSP are presented in this study.
Feedback controller design for a boost converter through evolutionary algorithms
Authors: Sundareswaran Kinattingal , Devi Vadakke , Sankar Selvakumar , Nayak Panugothu Srininivasa Rao , Peddapati Sankar
Published: November 2013

This study explains a systematic design procedure for the output voltage regulation of a boost‐type DC–DC converter employing evolutionary algorithms. The feedback controller design for output voltage regulation is formulated as an optimisation problem and the controller constants are identified via evolutionary search. The design procedure employing genetic algorithm, differential evolution and artificial immune system is lucidly described. Computer simulation results supported by experimental evidence clearly demonstrate that the controllers estimated through evolutionary algorithms are capable of delivering enhanced output voltage regulation under different types of load and supply disturbances.
Photothermal excitation of microcantilevers in liquid: effect of the excitation laser position on temperature and vibrational amplitude
Authors: Bircher Benjamin Andreas , Duempelmann Luc , Lang Hans Peter , Gerber Christoph , Braun Thomas
Published: November 2013

Demands to improve the sensitivity and measurement speed of dynamic scanning force microscopy and cantilever sensing applications necessitate the development of smaller cantilever sensors. As a result, methods to directly drive cantilevers, such as photothermal or magnetic excitation, are gaining in importance. Presented is a report on the effect of photothermal excitation of microcantilevers on the increase in steady‐state temperature and the dynamics of higher mode vibrations. First, the local temperature increase upon continuous irradiation with laser light at different positions along the cantilever was measured and compared with finite element analysis data. The temperature increase was highest when the heating laser was positioned at the free end of the cantilever. Next, the laser intensity was modulated to drive higher flexural modes to resonance. The dependence of the cantilever dynamics on the excitation laser position was assessed and was in good agreement with the analytical expressions. An optimal position to simultaneously excite all flexural modes of vibration with negligible heating was found at the clamped end of the cantilever. The reports findings are essential for optimisation of the excitation efficiency to minimise the rise in temperature and avoid damaging delicate samples or functionalisation layers.
Early Predictors of Health-Related Quality of Life Outcomes in Polytrauma Patients with Spine Injuries: A Level 1 Trauma Center Study
Authors: Tee J. W. , Chan C. H. P. , Gruen R. L. , Fitzgerald M. C. B. , Liew S. M. , Cameron P. A. , Rosenfeld J. V.
Published: November 2013

Study Design

Retrospective review on clinical-quality trauma registry prospective data.

Objective

To identify early predictors of suboptimal health status in polytrauma patients with spine injuries.

Methods

A retrospective review on a prospective cohort was performed on spine-injured polytrauma patients with successful discharge from May 2009 to January 2011. The Short Form 12-Questionnaire Health Survey (SF-12) was used in the health status assessment of these patients. Univariate and multivariate logistic regression models were applied to investigate the effects of the Injury Severity Score, age, blood sugar level, vital signs, brain trauma severity, comorbidities, coagulation profile, spine trauma-related neurologic status, and spine injury characteristics of the patients.

Results

The SF-12 had a 52.3% completion rate from 915 patients. The patients who completed the SF-12 were younger, and there were fewer patients with severe spinal cord injuries (American Spinal Injury Association classifications A, B, and C). Other comparison parameters were satisfactorily matched. Multivariate logistic regression revealed five early predictive factors with statistical significance ( p ≤ 0.05). They were (1) tachycardia (odds ratio [OR] = 1.88; confidence interval [CI] = 1.11 to 3.19), (2) hyperglycemia (OR = 2.65; CI = 1.51 to 4.65), (3) multiple chronic comorbidities (OR = 2.98; CI = 1.68 to 5.26), and (4) thoracic spine injuries (OR = 1.54; CI = 1.01 to 2.37). There were no independent early predictive factors identified for suboptimal mental health-related qualify of life outcomes.

Conclusion

Early independent risk factors predictive of suboptimal physical health status identified in a level 1 trauma center in polytrauma patients with spine injuries were tachycardia, hyperglycemia, multiple chronic medical comorbidities, and thoracic spine injuries. Early spine trauma risk factors were shown not to predict suboptimal mental health status outcomes.
Nonsnaking doubly diffusive convectons and the twist instability
Authors: Beaume Cédric , Knobloch Edgar , Bergeon Alain
Published: November 2013

Doubly diffusive convection in a three-dimensional horizontally extended domain with a square cross section in the vertical is considered. The fluid motion is driven by horizontal temperature and concentration differences in the transverse direction. When the buoyancy ratio N = −1 and the Rayleigh number is increased the conduction state loses stability to a subcritical, almost two-dimensional roll structure localized in the longitudinal direction. This structure exhibits abrupt growth in length near a particular value of the Rayleigh number but does not snake. Prior to this filling transition the structure becomes unstable to a secondary twist instability generating a pair of stationary, spatially localized zigzag states. In contrast to the primary branch these states snake as they grow in extent and eventually fill the whole domain. The origin of the twist instability and the properties of the resulting localized structures are investigated for both periodic and no-slip boundary conditions in the extended direction.
IR mass-resolved spectroscopy of complexes without chromophore: Cyclohexanol·(H2O)n, n = 1–3 and cyclohexanol dimer
Authors: León Iker , Montero Raúl , Longarte Asier , Fernández José A.
Published: November 2013

Mass-resolved IR spectra of cyclohexanol-water clusters and cyclohexanol dimer in supersonic expansions are presented for the first time. A combination of ns and fs IR lasers made possible recording such spectra without inclusion of a chromophore or a messenger atom. Furthermore, employment of the recently developed IR3 technique [I. León, R. Montero, F. Castaño, A. Longarte, and J. A. Fernández, J. Phys. Chem. A 116, 6798 (2012)] allowed us to discriminate between the contribution of different species to the IR spectrum. Comparison of the experimental spectra with the predictions at the M06-2X/6-311++G(d,p) calculation level confirmed the assignment of the spectrum of cyclohexanol·(H2O)1 to a structure in which water is accepting a proton from cyclohexanol's OH group, and those of cyclohexanol·(H2O)2,3 to structures with cyclic hydrogen bond networks. A comparative analysis of the results obtained with those reported on other aromatic alcohols is also offered.
Mixed quantum/classical theory of rotationally and vibrationally inelastic scattering in space-fixed and body-fixed reference frames
Authors: Semenov Alexander , Babikov Dmitri
Published: November 2013

We formulated the mixed quantum/classical theory for rotationally and vibrationally inelastic scattering process in the diatomic molecule + atom system. Two versions of theory are presented, first in the space-fixed and second in the body-fixed reference frame. First version is easy to derive and the resultant equations of motion are transparent, but the state-to-state transition matrix is complex-valued and dense. Such calculations may be computationally demanding for heavier molecules and/or higher temperatures, when the number of accessible channels becomes large. In contrast, the second version of theory requires some tedious derivations and the final equations of motion are rather complicated (not particularly intuitive). However, the state-to-state transitions are driven by real-valued sparse matrixes of much smaller size. Thus, this formulation is the method of choice from the computational point of view, while the space-fixed formulation can serve as a test of the body-fixed equations of motion, and the code. Rigorous numerical tests were carried out for a model system to ensure that all equations, matrixes, and computer codes in both formulations are correct.