bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of procedure volume on outcomes after iliac artery angioplasty and stenting
Authors: Goode S D , Keltie K , Burn J , Patrick H , Cleveland T J , Campbell B , Gaines P , Sims A J
Published: July 2013

Background

Service reorganization to concentrate complex vascular services in hospitals with high caseload volume aims to reduce mortality and complication rates. The present study assessed the relationship between caseload volume and outcome for iliac artery angioplasty and stenting in England using a routinely available national data set (Hospital Episode Statistics, HES).

Methods

Routine administrative data for iliac artery angioplasty and stent procedures performed in England between 2007 and 2011 were analysed. Associations between centre volume and outcomes (death, complications and duration of hospital stay) were tested and compared for two methods of stratification (quartiles and quintiles) and two statistical tests (odds ratios and the Cochran–Armitage test for trend). Multivariable analysis was also performed.

Results

There were 23 308 episodes of care recorded in HES with Office of Population Censuses and Surveys Classification of Surgical Operations and Procedures, fourth revision, codes L54.1 or L54.4 corresponding to iliac artery intervention. There was a gradual increase year by year in number of procedures performed. Univariable and multivariable analysis showed no association between centre volume and either death or complications (multivariable odds ratio, OR 1·00, 95 per cent confidence interval 1·00 to 1·00) for elective and non-elective procedures. Age was associated with higher mortality and complication rates in elective procedures, and with mortality in non-elective procedures. The risk of death after elective iliac angioplasty or stenting was significantly higher in women (multivariable OR 4·98, 2·09 to 13·26).

Conclusion

There was no association between the outcomes of endovascular iliac artery intervention and centre volume, but outcomes were significantly worse with increasing age and female sex.
Multicentre observational study of performance variation in provision and outcome of emergency appendicectomy
Authors:   National Surgical Research Collaborative, Bhangu A
Published: July 2013

Background

Identification of variation in practice is a key step towards standardization of service and determination of reliable quality markers. This study aimed to investigate variation in provision and outcome of emergency appendicectomy.

Methods

A multicentre, trainee-led, protocol-driven, prospective observational cohort study was performed during May and June 2012. The main outcome of interest was the normal histopathology rate; secondary outcomes were laparoscopy and 30-day adverse event rates. Analysis included funnel plots and binary logistic regression models to identify patient- and hospital-related predictors of outcome.

Results

A total of 3326 patients from 95 centres were included. An initial laparoscopic approach was performed in 66·3 per cent of patients (range in centres performing more than 25 appendicectomies over the study period: 8·7–100 per cent). A histologically normal appendix was removed in 20·6 per cent of patients (range in centres performing more than 25 procedures: 3·3–36·8 per cent). Funnel plot analysis revealed that 22 centres fell below three standard deviations of the mean for laparoscopy rates. Higher centre volume, consultant presence in theatre and daytime surgery were independently associated with an increased use of laparoscopy, which in turn was associated with a reduction in 30-day morbidity (adjusted for disease severity). Daytime surgery further reduced normal appendicectomy rates. Increasing volume came at the cost of higher negative rates, and low negative rates came at the cost of higher perforation rates.

Conclusion

This study reveals the extremely wide variation in practice patterns and outcomes among hospitals. Organizational factors leading to this variation have been identified and should be addressed to improve performance.
Rural hospital mass casualty response to a terrorist shooting spree
Authors: Waage S , Poole J C , Thorgersen E B
Published: July 2013

Background

Civilian mass casualty incidents may occur infrequently and suddenly, and are caused by accidents, natural disasters or human terrorist incidents. Most reports deal with trauma centre management in large cities, and data from small local hospitals are scarce. A rural hospital response to a mass casualty incident caused by a terrorist shooting spree was evaluated.

Methods

An observational study was undertaken to evaluate the triage, diagnosis and management of all casualties received from the Utøya youth camp in Norway on 22 July 2011 by a local hospital, using data from the hospital's electronic records. Descriptive data are presented for patient demographics, injuries and patient flow.

Results

The shooting on Utøya youth camp left 69 people dead and 60 wounded. A rural hospital (Ringerike Hospital) triaged 35 patients, of whom 18 were admitted. During the main surge, the hospital triaged and treated 22 patients within 1 h, of whom 13 fulfilled the criteria for activating the hospital trauma team, including five with critical injuries (defined as an Injury Severity Score above 15). Ten computed tomography scans, two focused assessment with sonography for trauma (FAST) scans and 25 conventional X-rays were performed. During the first 24 h, ten surgical procedures were performed and four chest drains inserted. No patient died.

Conclusion

Critical deviation from the major incident plan was needed, and future need for revision is deemed necessary based on the experience. Communication systems and the organization of radiological services proved to be most vulnerable.
Metal–Organic Framework Supported Bimetallic NiPt Nanoparticles as High‐performance Catalysts for Hydrogen Generation from Hydrazine in Aqueous Solution
Authors: Singh Ashish Kumar , Xu Qiang
Published: July 2013

Highly dispersed bimetallic NiPt nanoparticles with different NiPt compositions have been successfully immobilized by the zeolitic metal–organic framework ZIF‐8 by a simple liquid impregnation method. These catalysts show high catalytic activity and durability for hydrogen generation from decomposition of hydrazine (H2NNH2) in aqueous alkaline solution at 323 K. Both transmission electron microscopic (TEM) and high‐angle annular dark‐field scanning TEM measurements (HAADF‐STEM) images showed that the ZIF‐8 immobilized NPs were highly dispersed and controlled in small sizes with an average diameter of 2.2±0.3 nm.
Facile Synthesis of a Nanocrystalline Metal–Organic Framework Impregnated with a Phosphovanadomolybdate and Its Remarkable Catalytic Performance in Ultradeep Oxidative Desulfurization
Authors: Liu Yiwei , Liu Shumei , Liu Shuxia , Liang Dadong , Li Shujun , Tang Qun , Wang Xingquan , Miao Jun , Shi Zhan , Zheng Zhiping
Published: July 2013

Reducing the level of sulfur content in fuel oils has long been desired for environmental reasons. Polyoxometalates (POMs) can act as catalysts to remove sulfur‐containing heterocyclic compounds by the process of oxidative desulfurization under mild conditions. However, one key obstacle to the development of POM‐based catalysts is the poor solubility of POMs in the overall nonpolar environment. We report a novel strategy for the introduction of catalytically active POMs into nonpolar reaction systems by encapsulating the inorganic catalyst within the pores of a metal–organic framework structure in which the organic ligands act as hydrophobic groups. The nanocrystalline catalysts, obtained rapidly and conveniently by both solution and mechanochemical synthesis, showed remarkable activities in catalytic oxidative desulfurization reactions in both a model diesel environment and in real diesel wherein dibenzothiophene was converted rapidly and quantitatively into dibenzothiophene sulfone.
Simultaneous Electrochemical Multiplexed Immunoassay of Biomarkers Based on Multifunctionalized Graphene Nanotags
Authors: Li Qunfang , Tang Dianping , Lou Fangming , Yang Ximei , Chen Guonan
Published: July 2013

A sensitive and feasible multiplexed immunoassay protocol for simultaneous electrochemical determination of carcinoembryonic antigen (CEA) and alpha‐fetoprotein (AFP) was developed using multifunctionalized graphene nanotags on a cyclodextrin‐modified immunosensor. The sensor was fabricated via the guest–host chemistry between the immobilized cyclodextrin and anti‐CEA/anti‐AFP antibodies. Two nanotags including cyclodextrin‐thionine‐graphene and cyclodextrin‐ferrocene‐graphene nanostructures were synthesized based on a wet chemistry method. The synthesized nanotags were employed for the labelling of horseradish peroxidase (HRP)–anti‐AFP and HRP–anti‐CEA conjugates, respectively. With a sandwich‐type assay format, the signal was monitored through the labelling of HRP toward catalytic reduction of H2O2 at various peak potentials in the presence of thionine and ferrocene, respectively. Under optimal conditions, the multiplexed immunoassay enabled the simultaneous determination of CEA and AFP with wide working ranges of 0.001–60 ng mL−1 for AFP and 0.003–40 ng mL−1 for CEA. The detection limits were 0.5 pg ml−1 for AFP and 0.8 pg ml−1 for CEA (at 3 sB). No obvious nonspecific adsorption and cross‐talk were observed during a series of analyses to detect target analytes. Intra‐ and inter‐assay coefficients of variation (CV) were below 9.5 %. Importantly, the methodology was also evaluated for the analysis of AFP and CEA in the clinical human serum specimens, receiving a good relationship between the developed immunoassay and a commercialized electrochemiluminescence enzyme‐linked immunoassay.
Gold‐Catalyzed Cyclization of 1‐(Indol‐3‐yl)‐3‐alkyn‐1‐ols: Facile Synthesis of Diversified Carbazoles
Authors: Zhang Zhen , Tang Xiangying , Xu Qin , Shi Min
Published: July 2013

Efficient cyclization of 1‐(indol‐3‐yl)‐3‐alkyn‐1‐ols in the presence of a cationic gold(I) complex, leading to annulated or specific substituted carbazoles, was observed. Depending on the reaction conditions and substitution pattern, divergent reaction pathways were discovered, furnishing diversified carbazole structures. Cycloalkyl‐annulated [b]carbazoles are obtained through 1,2‐alkyl migration of the metal‐carbene intermediates; cycloalkyl‐annulated [a]carbazoles are formed through a Wagner–Meerwein‐type 1,2‐alkyl shift; carbazole ethers are constructed through ring‐opening of the cyclopropyl group by nucleophilic attack of water or an alcohol.
Aortic Dissection During Pregnancy: A Difficult Clinical Scenario
Authors: Yuan Shi‐Min
Published: July 2013

Aortic dissection (AoD) during pregnancy is a rare but lethal condition and highlights the need for extensive elucidation. The aim of this study is to reveal the risk factors for AoD during pregnancy and to compare the 2 main risk factors, Marfan syndrome and pregnancy itself in the previously healthy woman. The pregnant patients developed AoD at 31.7 ± 7.6 weeks of gestation. It occurred much earlier in the Marfan patients than in the previously healthy women (30.7 ± 8.6 weeks of gestation vs 34.4 ± 4.4 weeks of gestation, P = 0.0263). In the Marfan patients, AoD developed in 3 (3.2%), 15 (15.8%), and 43 (46.3%) patients in the 3 trimesters, respectively, compared with 31 of the previously healthy women, and only in the third trimester. The neonates of the Marfan patients had better Apgar scores at 1 and 5 minutes, lower intubation rates, and fewer stays in the neonatal intensive care unit than those of the previously healthy women. Marfan syndrome and pregnancy itself in the previously healthy woman were the 2 main risk factors responsible for the occurrence of AoD during pregnancy. Marfan patients may develop AoD at an early age and an early stage of pregnancy, probably due to the preexisting weakened aortic wall. Better outcomes for the surviving neonates of Marfan patients compared with neonates of the previously healthy women might be the result of the poor condition of Marfan patients causing a higher death rate for those fetuses.
RSEL: revocable secure efficient lightweight RFID authentication scheme
Authors: Fan Kai , Li Jie , Li Hui , Liang Xiaohui , Shen Xuemin (Sherman) , Yang Yintang
Published: July 2013

Radio frequency identification (RFID) has been regarded as one of the 10 important technologies in the 21st century. Because of its capability to rapidly and accurately collect and process data in real‐time, RFID has been widely applied in many areas, such as Internet of Things and Smart Grid. However, the existing security threats become more severe toward RFID authentication scheme. The traditional security mechanisms cannot be used in RFID directly because of the limitations of processing capability, storage space, and power supply of RFID tags. In this paper, we propose a revocable secure efficient lightweight RFID authentication scheme (RSEL). To achieve authentication efficiency, the key of the tag is chosen to reduce the number of hash computing in the database. Furthermore, the key is stored in the database and updated constantly with the tag to prevent the tracking and synchronization attacks. The valid period of each tag is stored in the database so that RSEL can revoke the expired tag. The correctness of RSEL has been proved using GNY logic. The performance of RSEL in terms of security and efficiency is evaluated. Compared with other existing approaches, RSEL achieves stronger security and higher efficiency. Copyright © 2013 John Wiley & Sons, Ltd.
Interaction of Platinum Nanoparticles with Graphitic Carbon Structures: A Computational Study
Authors: Schneider Wolfgang B. , Benedikt Udo , Auer Alexander A.
Published: July 2013

The interaction of platinum nanoparticles from a size of a few atoms up to 1 nm with extended carbon structures is studied by using quantum chemical methods. The aim is to obtain a deeper insight into the basic interactions between metal particles and carbon structures. For this purpose focus is placed on the type and strength of the interactions as well as the possibility to increase the adhesive forces by introducing chemical modifications (linker atoms) and defect sites or distortions of the support. The calculations show that there is a transition between an interaction with covalent character for smaller clusters and a dispersion‐dominated interaction for larger particles. Furthermore, introduced linker atoms increase the covalent character of the interactions but also increase the distance between the cluster and the support, thereby leading to a lower interaction energy. This has implications for the design of chemical linkers or surface modifications to improve the durability of catalyst systems.
The Dissolution of Polyols in Salt Solutions and Ionic Liquids at Molecular Level: Ions, Counter Ions, and Hofmeister Effects
Authors: Papanyan Zakar , Roth Christian , Wittler Kai , Reimann Sebastian , Ludwig Ralf
Published: July 2013

The dissolving process of polyols in salt solutions (TBAF, TBAC, TBAB, TBAI, TMAF) and imidazolium‐based ionic liquids ([C2mim][OAc], [C2mim][Et2PO4], [C2mim][EtSO4], [C2mim][SCN]) is exemplarily studied by IR spectroscopy. Vibrational bands and their shifts in the OH stretch region reveal crucial information for the dissolved polyol interacting with the anions of the salt solutions and ionic liquids. The well‐chosen set of ionic solutions confirms the linear relation between the OH‐stretch frequencies and the solubility capacity of the salt solutions. Likewise, it also provides an explanation of the dissolving process at molecular level. Notably, the solubility capacities of the anions in the salt solutions follow the well‐known Hofmeister series. This phenomenon can be understood on the basis of the disruption power of the anions and the specific size ratio of the anion/cation combinations.
Catalytic Deoxydehydration of Diols to Olefins by using a Bulky Cyclopentadiene‐based Trioxorhenium Catalyst
Authors: Raju Suresh , Jastrzebski Johann T. B. H. , Lutz Martin , Klein Gebbink Robertus J. M.
Published: July 2013

A bulky cyclopentadienyl (Cp)‐based trioxorhenium compound was developed for the catalytic deoxydehydration of vicinal diols to olefins. The 1,2,4‐tri(tert‐butyl)cyclopentadienyl trioxorhenium (2) catalyst was synthesised in a two‐step synthesis procedure. Dirhenium decacarbonyl was converted into 1,2,4‐tri(tert‐butyl)cyclopentadienyl tricarbonyl rhenium, followed by a biphasic oxidation with H2O2. These two new three‐legged compounds with a ‘piano‐stool’ configuration were fully characterised, including their single crystal X‐ray structures. Deoxydehydration reaction conditions were optimised by using 2 mol % loading of 2 for the conversion of 1,2‐octanediol into 1‐octene. Different phosphine‐based and other, more conventional, reductants were tested in combination with 2. Under optimised conditions, a variety of vicinal diols (aromatic and aliphatic, internal and terminal) were converted into olefins in good to excellent yields, and with minimal olefin isomerisation. A high turnover number of 1400 per Re was achieved for the deoxydehydration of 1,2‐octanediol. Furthermore, the biomass‐derived polyols (glycerol and erythritol) were converted into their corresponding olefinic products by 2 as the catalyst.
Estimation of Optimal Measurement Position of Human Forearm EMG Signal by Discriminant Analysis Based on Wilks’ Lambda
Authors: Kiso Atsushi , Taniguchi Yu , Seki Hirokazu
Published: July 2013

This paper describes the estimation of the optimal measurement position by discriminant analysis based on Wilks’ lambda for myoelectric hand control. In previous studies, for motion discrimination, the myoelectric signals were measured at the same positions. However, the optimal measurement positions of the myoelectric signals for motion discrimination differ depending on the remaining muscles of amputees. Therefore, the purpose of this study is to estimate the optimal and fewer measurement positions for precise motion discrimination of a human forearm. This study proposes a method for estimating the optimal measurement positions by discriminant analysis based on Wilks’ lambda, using the myoelectric signals measured at multiple positions. The results of some experiments on the myoelectric hand simulator show the effectiveness of the proposed optimal measurement position estimation method. © 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 96(8): 32–40, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11465
Calculation of Time‐Resolved Energy Distribution of Electrons by PT‐FTI Method
Authors: Takeda Akihide , Ikuta Nobuaki
Published: July 2013

A new procedure to obtain the time‐resolved energy distribution of electrons in gas under a static electric field, the PT‐FTI method, has been developed taking the circulation flow rate distribution through the loop of a flight and a collision as the principal unknown function. Iterative operations of two‐dimensional loop dispersion functions in the time and energy domains to an initial starting energy distribution give a series of time‐dependent flow rate distributions in successive circulations. The time‐resolved energy distribution and transport quantities of electrons in flight are derived from them. The fact that the PT‐FTI method gives converging results the same as obtained in the FTI method assures the validity of both the PT‐FTI and FTI methods. © 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 96(8): 18–25, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11470
Localized Induced Current Stimulation to Neuronal Culture Using Soft Magnetic Material
Authors: Saito Atsushi , Saito Aki , Moriguchi Hiroyuki , Kotani Kiyoshi , Jimbo Yasuhiko
Published: July 2013

To establish precisely focused magnetic stimulation, we developed a Mu‐metal‐based low‐frequency localized induced current (LIC) stimulation system with microfabricated dual cell‐culture chamber. The dual cell‐culture chamber was arranged in a concentric circle manner. Between the inner and outer chambers, four or eight connecting microchannels were fabricated using polydimethylsiloxane (PDMS). Rat cortical neurons were separately cultured in outer and inner chambers. Through the micro‐channels, functional synaptic connections were formed. Mu‐metal with very high magnetic permeability was aligned along the outer circle, which allowed the application of LIC stimulation to the cells in the outer chamber. Applying low‐frequency magnetic fields to the Mu‐metal, induced currents were generated and the electrical activity of the cells in the outer chamber was modified depending on the stimulation intensity. Following the modified activity in the outer circles, the cells in the inner chamber also showed slightly depressed activity patterns. These results suggested that our system would be promising for localized stimulation of neuronal networks and highly effective regulation of network activities. © 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 96(8): 9–17, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11473
IL‐17 plays a central role in initiating experimental Candida albicans infection in mouse corneas
Authors: Zhang Hongbo , Li Hongxia , Li Yuanyuan , Zou Yanli , Dong Xiaomeng , Song Wengang , Jia Changkai , Li Siyuan , Xi Haijie , Liu Dongmin , Wang Yiqiang
Published: July 2013

The pathogenesis of fungal infection in the cornea remains largely unclear. To understand how the immune system influences the progression of fungal infection in corneas, we inoculated immunocompetent BALB/c mice, neutrophil‐ or CD4+ T‐cell‐depleted BALB/c mice, and nude mice with Candida albicans. We found that only immunocompetent BALB/c mice developed typical Candida keratitis (CaK), while the other mouse strains lacked obvious clinical manifestations. Furthermore, CaK development was blocked in immunocompetent mice treated with anti‐IL‐17A or anti‐IL‐23p19 to neutralize IL‐17 activity. However, no significant effects were observed when Treg cells, γδ T cells, or IFN‐γ were immunodepleted. Upon infection, the corneas of BALB/c mice were infiltrated with IL‐17‐producing leukocytes, including neutrophils and, to a lesser degree, CD4+ T cells. In contrast, leukocyte recruitment to corneas was significantly diminished in nude mice. Indeed, nude mice produced much less chemokines (e.g. CXCL1, CXCL2, CXCL10, CXCL12, CCL2, and IL‐6) in response to inoculation. Remarkably, addition of CXCL2 during inoculation restored CaK induction in nude mice. In contrast to its therapeutic effect on CaK, neutralization of IL‐17 exacerbated Candida‐induced dermatitis in skin. We conclude that IL‐17, mainly produced by neutrophils and CD4+ T cells in the corneas, is essential in the pathogenesis of CaK.
Heterodimetallic Structures Based on Cyano‐Substituted Bis(dithiolene) Complexes and Ni and Cu Cyclam Cations
Authors: Cerdeira Ana C. , Belo Dulce , Rabaça Sandra , Pereira Laura C. J. , Coutinho Joana T. , Simão Dulce , Henriques Rui T. , Jeannin Olivier , Fourmigué Marc , Almeida Manuel
Published: July 2013

Five charge‐transfer salts based on the combination of anionic FeIII and CuII bis(dithiolene) complexes containing nitrile groups with [M(cyclam)]2+ (M = Ni, Cu) cations, namely, [Ni(cyclam)]2[Cu(dcbdt)2]2·4DMF (1, dcbdt = 4,5‐dicyanobenzene‐1,2‐dithiolate, DMF = N,N‐dimethylformamide), [Ni(cyclam)]2[Cu(dcdmp)2]2·4DMF (2, dcdmp = 2,3‐dicyano‐5,6‐dimercaptopyrazine), [Cu(cyclam)]2[Cu(dcdmp)2]2·4DMF (3), [Cu(cyclam)]2[Fe2(cbdt)4]2·4DMF (4, cbdt = 4‐cyanobenzene‐1,2‐dithiolate) and [Ni(cyclam)]2[Fe2(cbdt)4]2·4DMF (5), were prepared and characterised by X‐ray diffraction and magnetisation measurements. The crystal structures of 1–4 were determined by single‐crystal X‐ray diffraction, which revealed that the cyano groups from dithiolene complexes fail to coordinate the metal ions in the cyclam units. Instead, they are coordinated by solvent molecules or by dithiolene S atoms and cyclam N–H groups, which participate in hydrogen bonds to the nitrile and sulfur moieties in the anions.
Access to Cyclic α‐CF3‐Substituted α‐Amino Acid Derivatives by Ring‐Closing Metathesis of Functionalized 1,7‐Enynes
Authors: Mailyan Artur K. , Krylov Ivan M. , Bruneau Christian , Dixneuf Pierre H. , Osipov Sergey N.
Published: July 2013

An efficient method for the preparation of new α‐CF3 α‐amino acid 1,7‐enynes that contain electron‐donating and electron‐withdrawing groups on the triple bond has been developed that proceeds through a Sonogashira‐type coupling reaction. The ring‐closing enyne methathesis (RCEYM) of the obtained 1,7‐enynes with commercially available Grubbs and Hoveyda catalysts provides access to a series of new cyclic α‐amino acids. The latter compounds that contain the 1,3‐diene moiety are attractive building blocks for the construction of trifluoromethylated polycyclic systems.
SrO‐Containing Diopside Glass–Ceramic Sealants for Solid Oxide Fuel Cells: Mechanical Reliability and Thermal Shock Resistance
Authors: Reddy A. A. , Tulyaganov D. U. , Pascual M. J. , Kharton V. V. , Tsipis E. V. , Kolotygin V. A. , Ferreira J. M. F.
Published: July 2013

A series of glasses and glass–ceramics (GCs) aiming at applications as sealants for solid oxide fuel cells (SOFCs) were synthesized by partial substitution of Ca for Sr in the diopside‐Ba disilicate composition. X‐ray diffraction in conjunction with the Rietveld‐RIR technique were employed to quantify the crystalline (diopside and Sr‐diopside) and amorphous phases in the glasses sintered/heat treated at 850 °C in humidified 10%H2–90%N2 gas mixture for 250 h. Weibull modulus varied in the range 11.6–34.4 implying toward good mechanical reliability of synthesized GCs. Thermal shock resistance of model electrochemical cells made of yttria‐stabilized zirconia, gadolinia‐doped ceria, and lanthanum gallate based solid electrolytes, hermetically sealed by one diopside‐based composition, was evaluated employing quenching from 800 °C in air and water. Suitable thermal expansion coefficient, mechanical reliability, and strong adhesion to stabilized zirconia and metallic interconnects, are all suggesting a good suitability of the sealants for SOFC applications.
Investigation of the Mechanical Stability of Micro‐Solid Oxide Fuel Cell Membranes Using Scanning Laser Vibrometry
Authors: Tölke R. , Gauckler L. J. , Kunz U. , Krauss A. , Prestat M.
Published: July 2013

Scanning laser vibrometry was used to investigate the mechanical stability of free‐standing micro‐solid oxide fuel cell (micro‐SOFC) membranes. Arrays of square‐shaped 460 nm thin micro‐SOFC membranes were fabricated on silicon substrates using pulsed laser deposition for the yttria‐stabilized zirconia electrolyte and magnetron sputtering for the platinum electrodes. Resonance frequency, displacement and acceleration measurements were carried out using interferometry analysis of the membrane reflection. The resonance frequencies scale with the reciprocal of the membrane length. At the resonance, the 390 × 390 μm2 micro‐SOFC membranes exhibit an out‐of‐plane displacement of ca. 1.2 μm only. All free‐standing micro‐SOFC membranes survive the resonant vibration without rupturing. These results are promising for the failure‐free implementation of micro‐SOFC in portable electronic devices.
Oxygen isotopes in subducted oceanic crust: A new perspective from Siberian diamondiferous eclogites
Authors: Carmody Laura , Barry Peter H. , Shervais John W. , Kluesner Jared W. , Taylor Lawrence A.
Published: July 2013

There are three methods of investigating the oxygen‐isotope composition of oceanic crust: (1) data from drilling‐obtained samples; (2) study of obducted ophiolites; and (3) from crustal‐derived xenoliths; however, each approach has limitations. Drilling capabilities are limited to the upper 1–3 km of the oceanic crust. Ophiolites are segments of oceanic crust and underlying mantle exposed at the Earth's surface, but their origin and emplacement are still debated. Nonetheless, the study of ophiolite sequences has enabled many of the fundamental observations regarding ancient‐oceanic crust and the oxygen‐isotope signature of the upper mantle. Analyses of ophiolite sequences (e.g., Samail) reveal δ18O variations ranging from isotopically enriched in relation to MORB (δ18O > MORB) to isotopically depleted (low δ18O ≤ MORB), interpreted to show the effects of seawater interaction at different temperatures. Mantle‐derived xenoliths also display compelling geochemical evidence suggesting they are remnants of subducted ocean crust, and may in fact, be more representative samples. Some kimberlite‐hosted diamondiferous eclogite xenoliths, with crustal protoliths, reveal a marked oxygen‐isotope disparity between oceanic crust and the upper mantle; i.e., a bimodal distribution of both mantle‐like (δ18O ≈ 5.6‰) and isotopically enriched oxygen (δ18O ≈ 6.8‰). The isotopically high δ18O values are often observed in eclogite xenoliths with ultramafic protoliths, which form beyond the low‐temperature alteration zone. This finding is in contrast to traditional oxygen‐isotope versus depth‐curves of ophiolite sequences. Here, we present a compiled data set from Siberian eclogites and pyroxenites that illustrates this bimodality, using magnesium number (Mg#) as a depth proxy, and investigate the conditions that could potentially result in the observed “abnormal” oxygen‐isotope variations.
Magma storage and ascent conditions beneath Pico and Faial islands (Azores archipelago): A study on fluid inclusions
Authors: Zanon Vittorio , Frezzotti Maria Luce
Published: July 2013

In the islands of Faial and Pico (the Azores), fluid inclusions are hosted in megacrysts of olivine (Mg#80–88) and clinopyroxene (Mg#79–90) in highly porphyritic lavas and in mineral assemblages of ultramafic xenoliths. Rare inclusions are contained in olivine phenocrysts (Mg# < 80) and plagioclases in poorly porphyritic lavas. Trails of late‐stage inclusions are predominant over isolated early‐stage inclusions. Almost all inclusions are re‐equilibrated and the trapped fluid consists of pure CO2 (Tm from −56.5 to −57.2). Rare early‐stage inclusions may contain dypingite or Mg‐calcite, which indicates that in earlier times some water was present along with CO2. Barometric data indicate that CO2 inclusions in xenoliths from the two islands equilibrated at maximum pressures of 570–586 MPa (19.7–21.2 km), while in poorly porphyritic lavas from all the fissure zones at 465–508 MPa (16.4–18.1 km). Maximum pressure values of 463 MPa (16.8 km) and 492 MPa (17 km) were recorded for the central volcanoes of Pico and Faial, respectively. Further trapping/re‐equilibration was recorded at 156 MPa in Faial (5.6 km), in plagioclase phenocrysts in mugearites. All these pressures correspond to magma ponding sites and to its crystallization and can be useful for tracing the progressive thickening of a dense transition zone, below the geophysical Moho. The ability to extract rapidly the stored magmas from these volcanic systems strictly depends on the different tectonic styles, acting in this transition zone. Magmatic evolution in small and short‐lived intracrustal reservoirs, not necessarily coaxial with main conduit system, was enhanced at the intersection of differently oriented lineaments.
Spinal muscular atrophy astrocytes exhibit abnormal calcium regulation and reduced growth factor production
Authors: McGivern Jered V. , Patitucci Teresa N. , Nord Joshua A. , Barabas Marie‐Elizabeth A. , Stucky Cheryl L. , Ebert Allison D.
Published: July 2013

Spinal muscular atrophy (SMA) is a genetic disorder caused by the deletion of the survival motor neuron 1 (SMN1) gene that leads to loss of motor neurons in the spinal cord. Although motor neurons are selectively lost during SMA pathology, selective replacement of SMN in motor neurons does not lead to full rescue in mouse models. Due to the ubiquitous expression of SMN, it is likely that other cell types besides motor neurons are affected by its disruption and therefore may contribute to disease pathology. Here we show that astrocytes in SMAΔ7 mouse spinal cord and from SMA‐induced pluripotent stem cells exhibit morphological and cellular changes indicative of activation before overt motor neuron loss. Furthermore, our in vitro studies show mis‐regulation of basal calcium and decreased response to adenosine triphosphate stimulation indicating abnormal astrocyte function. Together, for the first time, these data show early disruptions in astrocytes that may contribute to SMA disease pathology.
Myelin inhibits oligodendroglial maturation and regulates oligodendrocytic transcription factor expression
Authors: Plemel Jason R. , Manesh Sohrab B. , Sparling Joseph S. , Tetzlaff Wolfram
Published: July 2013

Myelin loss is a hallmark of multiple sclerosis (MS) and promoting central nervous system myelin repair has become a major therapeutic target. Despite the presence of oligodendrocytes precursors cells (OPCs) in chronic lesions of MS, remyelination often fails. The mechanism underlying this failure of remyelination remains unknown, but it is hypothesized that environmental cues act to inhibit the maturation/differentiation of oligodendroglia, preventing remyelination. The rate of CNS remyelination is correlated to the speed of phagocytosis of myelin debris, which is present following demyelination and trauma. Thus, myelin debris could inhibit CNS remyelination. Here, we demonstrate that OPCs cultured on myelin were robustly inhibited in their maturation, as characterized by the decreased expression of immature and mature oligodendrocytes markers, the impaired production of myelin gene products, as well as their stalled morphological complexity relative to OPCs cultured on a control substrate. OPCs in contact with myelin stopped proliferating and decreased the expression of OPC markers to a comparable degree as cells grown on a control substrate. The expression of two transcription factors known to prevent OPC differentiation and maturation were increased in cells that were in contact with myelin: inhibitor of differentiation family (ID) members 2 and 4. Overexpression of ID2 and ID4 in OPCs was previously reported to decrease the percentage of cells expressing mature oligodendrocyte markers. However, knockdown of ID2 and/or ID4 in OPCs did not increase oligodendroglial maturation on or off of myelin, suggesting that contact with myelin regulates additional regulatory elements.
Expression profiling of Aldh1l1‐precursors in the developing spinal cord reveals glial lineage‐specific genes and direct Sox9‐Nfe2l1 interactions
Authors: Molofsky Anna V. , Glasgow Stacey M. , Chaboub Lesley S. , Tsai Hui‐Hsin , Murnen Alice T. , Kelley Kevin W. , Fancy Stephen P.J. , Yuen Tracy J. , Madireddy Lohith , Baranzini Sergio , Deneen Benjamin , Rowitch David H. , Oldham Michael C.
Published: July 2013

Developmental regulation of gliogenesis in the mammalian CNS is incompletely understood, in part due to a limited repertoire of lineage‐specific genes. We used Aldh1l1‐GFP as a marker for gliogenic radial glia and later‐stage precursors of developing astrocytes and performed gene expression profiling of these cells. We then used this dataset to identify candidate transcription factors that may serve as glial markers or regulators of glial fate. Our analysis generated a database of developmental stage‐related markers of Aldh1l1+ cells between murine embryonic day 13.5–18.5. Using these data we identify the bZIP transcription factor Nfe2l1 and demonstrate that it promotes glial fate under direct Sox9 regulatory control. Thus, this dataset represents a resource for identifying novel regulators of glial development.
GFAP expression and social deficits in transgenic mice overexpressing human sAPPα
Authors: Bailey Antoinette R. , Hou Huayan , Song Min , Obregon Demian F. , Portis Samantha , Barger Steven , Shytle Doug , Stock Saundra , Mori Takashi , Sanberg Paul G. , Murphy Tanya , Tan Jun
Published: July 2013

Autistic individuals display impaired social interactions and language, and restricted, stereotyped behaviors. Elevated levels of secreted amyloid precursor protein‐alpha (sAPPα), the product of α‐secretase cleavage of APP, are found in the plasma of some individuals with autism. The sAPPα protein is neurotrophic and neuroprotective and recently showed a correlation to glial differentiation in human neural stem cells (NSCs) via the IL‐6 pathway. Considering evidence of gliosis in postmortem autistic brains, we hypothesized that subsets of patients with autism would exhibit elevations in CNS sAPPα and mice generated to mimic this observation would display markers suggestive of gliosis and autism‐like behavior. Elevations in sAPPα levels were observed in brains of autistic patients compared to controls. Transgenic mice engineered to overexpress human sAPPα (TgsAPPα mice) displayed hypoactivity, impaired sociability, increased brain glial fibrillary acidic protein (GFAP) expression, and altered Notch1 and IL‐6 levels. NSCs isolated from TgsAPPα mice, and those derived from wild‐type mice treated with sAPPα, displayed suppressed β‐tubulin III and elevated GFAP expression. These results suggest that elevations in brain sAPPα levels are observed in subsets of individuals with autism and TgsAPPα mice display signs suggestive of gliosis and behavioral impairment.
Repopulation of the fibrotic/cirrhotic rat liver by transplanted hepatic stem/progenitor cells and mature hepatocytes
Authors: Yovchev Mladen I. , Xue Yuhua , Shafritz David A. , Locker Joseph , Oertel Michael
Published: July 2013

Considerable progress has been made in developing antifibrotic agents and other strategies to treat liver fibrosis; however, significant long-term restoration of functional liver mass has not yet been achieved. Therefore, we investigated whether transplanted hepatic stem/progenitor cells can effectively repopulate the liver with advanced fibrosis/cirrhosis. Stem/progenitor cells derived from fetal livers or mature hepatocytes from DPPIV+ F344 rats were transplanted into DPPIV− rats with thioacetamide (TAA)-induced fibrosis/cirrhosis; rats were sacrificed 1, 2, or 4 months later. Liver tissues were analyzed by histochemistry, hydroxyproline determination, reverse-transcription polymerase chain reaction (RT-PCR), and immunohistochemistry. After chronic TAA administration, DPPIV− F344 rats exhibited progressive fibrosis, cirrhosis, and severe hepatocyte damage. Besides stellate cell activation, increased numbers of stem/progenitor cells (Dlk-1+, AFP+, CD133+, Sox-9+, FoxJ1+) were observed. In conjunction with partial hepatectomy (PH), transplanted stem/progenitor cells engrafted, proliferated competitively compared to host hepatocytes, differentiated into hepatocytic and biliary epithelial cells, and generated new liver mass with extensive long-term liver repopulation (40.8 ± 10.3%). Remarkably, more than 20% liver repopulation was achieved in the absence of PH, associated with reduced fibrogenic activity (e.g., expression of alpha smooth muscle actin, platelet-derived growth factor receptor β, desmin, vimentin, tissue inhibitor of metalloproteinase-1) and fibrosis (reduced collagen). Furthermore, hepatocytes can also replace liver mass with advanced fibrosis/cirrhosis, but to a lesser extent than fetal liver stem/progenitor cells.

Conclusion :

This study is a proof of principle demonstration that transplanted epithelial stem/progenitor cells can restore injured parenchyma in a liver environment with advanced fibrosis/cirrhosis and exhibit antifibrotic effects.
VARIABILITY IN INTENSITY OF HEAVY RAINFALL DUE TO CLIMATE CHANGE AND ITS IMPACT ON PADDY INUNDATION IN LOW‐LYING AREAS OF JAPAN
Authors: Minakawa Hiroki , Masumoto Takao
Published: July 2013

The aim of this study was to detect changes in heavy rainfall patterns and to evaluate the impact of these changes on drainage systems in low‐lying areas. Our study area was in the Kaga three‐lagoon basin in Ishikawa Prefecture, Japan. First, heavy rainfall events were extracted from observed rainfall data from 1940 through 2008. Comparison of the hourly data showed that the average maximum 6‐, 12‐, 24‐, and 48‐h rainfall increased slightly over the 69 years and that the distribution of the maximum amount of 6‐h rainfall also changed. Next, rainfall data predicted by MIROC were examined. The results implied that the amount of rain in 3‐day rainfall events with a 10‐yr return period would reach a peak of 1.23 times the present amount in the near future. At the same time, a drainage analysis model was developed consisting of kinematic and diffusive tank models. The rainfall predicted by MIROC was used in the models to assess the impact of climate change on drainage systems. As a result, the duration of paddy inundation to a depth of more than 30 cm was estimated to increase in the future. Countermeasures, such as the improvement of pumping capacity, are suggested. Copyright © 2013 John Wiley & Sons, Ltd.
Observational evidence for the collapsing Langmuir wave packet in a solar type III radio burst
Authors: Thejappa G. , MacDowall R. J. , Bergamo M.
Published: July 2013

High time resolution observations from the STEREO spacecraft show that in solar type III radio bursts, Langmuir waves often occur as very intense one‐dimensional magnetic field aligned field structures. One of these events represents the most intense Langmuir wave packet with ever detected in a type III radio burst until now (WL is the peak energy density, and ne and Te are the electron density and temperature, respectively). The detailed analysis of this wave packet indicates that (1) its peak intensity is well above the threshold for the oscillating two‐stream instability (OTSI) and supersonic collapse; (2) its peak intensity and spatial scale satisfy the criterion for it to be a collapsing envelope soliton; (3) its low‐frequency components provide evidence for a density cavity, whose depth, width, and temporal coincidence indicate that probably it is the ponderomotive force generated density cavity; and (4) its spectrum contains harmonic peaks at 2fpe and 3fpe (in addition to the main Langmuir wave peak at the electron plasma frequency, fpe), which, as indicated by the bispectral analysis, probably are of the electromagnetic waves generated as a result of coalescence of two oppositely propagating Langmuir waves, and a Langmuir wave and a second harmonic electromagnetic wave, respectively. These characteristics strongly suggest that this wave packet and its associated density cavity represent the collapsing envelope soliton‐caviton pair formed as a result of OTSI, and in the present case, the strong turbulence processes probably play key roles in the beam stabilization as well as conversion of Langmuir waves into escaping radiation at 2fpe and 3fpe.
Time‐variable gravity signal in Greenland revealed by high‐low satellite‐to‐satellite tracking
Authors: Weigelt M. , van Dam T. , Jäggi A. , Prange L. , Tourian M. J. , Keller W. , Sneeuw N.
Published: July 2013

In the event of a termination of the Gravity Recovery and Climate Experiment (GRACE) mission before the launch of GRACE Follow‐On (due for launch in 2017), high‐low satellite‐to‐satellite tracking (hl‐SST) will be the only dedicated observing system with global coverage available to measure the time‐variable gravity field (TVG) on a monthly or even shorter time scale. Until recently, hl‐SST TVG observations were of poor quality and hardly improved the performance of Satellite Laser Ranging observations. To date, they have been of only very limited usefulness to geophysical or environmental investigations. In this paper, we apply a thorough reprocessing strategy and a dedicated Kalman filter to Challenging Minisatellite Payload (CHAMP) data to demonstrate that it is possible to derive the very long‐wavelength TVG features down to spatial scales of approximately 2000 km at the annual frequency and for multi‐year trends. The results are validated against GRACE data and surface height changes from long‐term GPS ground stations in Greenland. We find that the quality of the CHAMP solutions is sufficient to derive long‐term trends and annual amplitudes of mass change over Greenland. We conclude that hl‐SST is a viable source of information for TVG and can serve to some extent to bridge a possible gap between the end‐of‐life of GRACE and the availability of GRACE Follow‐On.
Parameterization of PAR vertical profile within horizontally uniform forest canopies for use in environmental modeling
Authors: Lalic Branislava , Firanj Ana , Mihailovic Dragutin T. , Podrascanin Zorica
Published: July 2013

The radiation transfer within the forest canopy plays crucial role in energy balance and turbulent transfer processes. Objective of this study is to suggest a new relation for vertical profile of photosynthetically active radiation (PAR) in case of horizontally uniform forest canopy. It is based on (i) the Lambert‐Beer law relationship and (ii) new parameterization of leaf area density (LAD) profile. We have supposed that absorption coefficient μ varies with height and depends on LAD distribution. To check validity of the relation proposed, we have compared calculated values with the observations using data sets assimilated during Anglo‐Brazilian Amazonian Climate Observation Study experiment at two observational sites located in Reserva Jaru and Reserva Ducke (Brazil) with different types of forest. Among all available measurements, 615 profiles observed between 08 and 18 local mean time for 72 days at 2 locations were selected. For comparison study, two more profiles based on constant‐ and variable‐LAD approximation were introduced. Obtained results indicate that suggested relation: (i) well reproduces PAR profile within the forest in comparison with observations and (ii) shows better agreement with observations in comparison with two other profiles used in this study.
Diffusion tensor MRI of the corpus callosum in amyotrophic lateral sclerosis
Authors: Chapman Molly C. , Jelsone‐Swain Laura , Johnson Timothy D. , Gruis Kirsten L. , Welsh Robert C.
Published: July 2013

Purpose

To determine if decline in corpus callosum (CC) white matter integrity in patients with amyotrophic lateral sclerosis (ALS) is localized to motor‐related areas.

Materials and Methods

Twenty‐one ALS patients and 21 controls participated. Diffusion tensor images (DTI) were acquired using 3 Tesla (T) MRI. Tract‐based spatial statistics were used to examine whole‐brain white matter damage. A segmentation schema was used to define CC volumes‐of‐interest (VOI). Fractional anisotropy (FA) and radial‐ and axial‐diffusivity (RD, AD) were extracted from VOIs and compared between groups. DTI measurements in motor‐related Area III were tested for correlation with symptoms and disease duration.

Results

Extracted FA values from CC VOIs were reduced in ALS patients (P ≤ 0.0001), particularly in Areas II and III (P ≤ 0.01). Reduced FA in Area III correlated with disease symptomology (P ≤ 0.05) and duration (P ≤ 0.02). Between‐group whole‐brain comparisons (P ≤ 0.05, corrected) showed reduced FA and increased RD throughout white matter regions including the CC, corona radiata, and internal capsule. AD was increased in the left corona radiata and internal and external capsules.

Conclusion

FA in motor‐related regions of the CC is more affected than other CC areas in ALS patients. Microstructural pathology of transcallosal fiber tracts may represent a future component of an imaging biomarker for ALS. J. Magn. Reson. Imaging 2014;39:641–647. © 2013 Wiley Periodicals, Inc.