bluuebunny/crossref_metadata_2025 huggingface dataset:
Is Steam an Oxidant or a Reductant for Nickel/Doped‐Ceria Cermets?
Authors: Papaefthimiou Vasiliki , Niakolas Dimitris K. , Paloukis Fotios , Dintzer Thierry , Zafeiratos Spyridon
Published: October 2016

Nickel/doped‐ceria composites are promising electrocatalysts for solid‐oxide fuel and electrolysis cells. Very often steam is present in the feedstock of the cells, frequently mixed with other gases, such as hydrogen or CO2. An increase in the steam concentration in the feed mixture is considered accountable for the electrode oxidation and the deactivation of the device. However, direct experimental evidence of the steam interaction with nickel/doped‐ceria composites, with adequate surface specificity, are lacking. Herein we explore in situ the surface state of nickel/gadolinium‐doped ceria (NiGDC) under O2, H2, and H2O environments by using near‐ambient‐pressure X‐ray photoelectron and absorption spectroscopies. Changes in the surface oxidation state and composition of NiGDC in response to the ambient gas are observed. It is revealed that, in the mbar pressure regime and at intermediate temperature conditions (500–700 °C), steam acts as an oxidant for nickel but has a dual oxidant/reductant function for doped ceria.
The challenge of separating signatures of local adaptation from those of isolation by distance and colonization history: The case of two white pines
Authors: Nadeau Simon , Meirmans Patrick G. , Aitken Sally N. , Ritland Kermit , Isabel Nathalie
Published: October 2016

Accurately detecting signatures of local adaptation using genetic‐environment associations (GEAs) requires controlling for neutral patterns of population structure to reduce the risk of false positives. However, a high degree of collinearity between climatic gradients and neutral population structure can greatly reduce power, and the performance of GEA methods in such case is rarely evaluated in empirical studies. In this study, we attempted to disentangle the effects of local adaptation and isolation by environment (IBE) from those of isolation by distance (IBD) and isolation by colonization from glacial refugia (IBC) using range‐wide samples in two white pine species. For this, SNPs from 168 genes, including 52 candidate genes for growth and phenology, were genotyped in 133 and 61 populations of Pinus strobus and P. monticola, respectively. For P. strobus and using all 153 SNPs, climate (IBE) did not significantly explained among‐population variation when controlling for IBD and IBC in redundancy analyses (RDAs). However, 26 SNPs were significantly associated with climate in single‐locus GEA analyses (Bayenv2 and LFMM), suggesting that local adaptation took place in the presence of high gene flow. For P. monticola, we found no evidence of IBE using RDAs and weaker signatures of local adaptation using GEA and FST outlier tests, consistent with adaptation via phenotypic plasticity. In both species, the majority of the explained among‐population variation (69 to 96%) could not be partitioned between the effects of IBE, IBD, and IBC. GEA methods can account differently for this confounded variation, and this could explain the small overlap of SNPs detected between Bayenv2 and LFMM. Our study illustrates the inherent difficulty of taking into account neutral structure in natural populations and the importance of sampling designs that maximize climatic variation, while minimizing collinearity between climatic gradients and neutral structure.
Ecosystem connectivity and trophic subsidies of sandy beaches
Authors: Liebowitz Dina M. , Nielsen Karina J. , Dugan Jenifer E. , Morgan Steven G. , Malone Daniel P. , Largier John L. , Hubbard David M. , Carr Mark H.
Published: October 2016

Ecological connectivity can influence the distributions of diversity and productivity among ecosystems, but relationships among multiple marine ecosystems remain relatively uncharacterized. Sandy beaches are recipient ecosystems that support coastal food webs through deposits of drift macrophytes (wrack), and serve as test cases for exploring within‐seascape connectivity. We present results from the first comprehensive survey of geographic and temporal patterns of wrack cover and composition on beaches along the North Central Coast of California and test the role of local donor ecosystems and physical factors in predicting wrack distribution. We surveyed wrack at 17 beaches in August 2010, and monthly at a subset of 10 beaches for 13 months. We estimated explanatory variables of (1) local donor ecosystem cover (kelp forests, rocky intertidal, and bays and estuaries), (2) biomass transport, and (3) beach morphology. Regression analyses were used to evaluate relationships among the cover of six key wrack categories and the explanatory variables above, for two time periods. We found persistent geographic variation in wrack composition and detected significant relationships between wrack cover and cover of local donor ecosystems for five of the six wrack categories (Nereocystis, Zostera, Postelsia, mixed red algae, and mixed brown algae). Transport mechanisms (wind exposure, swell exposure) or attributes of the recipient ecosystem (beach width, beach slope) explained additional spatial variation for three of the six wrack categories (Zostera, Phyllospadix, and mixed red algae). Our results support the concept of considering ecological connectivity (particularly the role of donor ecosystems upon which recipient ecosystems rely) in the design and management of protected areas.
Obesity paradox in heart failure: a heavy matter
Authors: Nagarajan Vijaiganesh , Kohan Luke , Holland Eric , Keeley Ellen C. , Mazimba Sula
Published: October 2016

Obesity and heart failure are two of the leading causes of morbidity and mortality in the world. The relationship between obesity and cardiovascular diseases is complex and not fully understood. While the risk of developing heart failure has been shown to be higher in patients who are obese, there is a survival advantage for obese and overweight patients compared with normal weight or low weight patients. This phenomenon was first described by Horwich et al. and was subsequently confirmed in other large trials. The advantage exists irrespective of the type, aetiology, or stage of heart failure. Patients with morbid obesity (body mass index >40 kg/m2), however, do not have the same survival advantage of their obese counterparts. There are several alternative indices of obesity available that may be more accurate than body mass index. The role of weight loss in patients with heart failure is unclear; thus, providing sound clinical advice to patients remains difficult. Future prospective trials designed to evaluate the link between obesity and heart failure will help us understand more fully this complex relationship.
New road for telecoupling global prosperity and ecological sustainability
Authors: Yang Dewei , Cai Jingjing , Hull Vanessa , Wang Kaiyong , Tsang Yin‐phan , Liu Jianguo
Published: October 2016

China's ambitious Belt and Road Initiative, which seeks to expand the ancient land routes that connect China to the Mediterranean Sea and corresponding ocean‐based routes, is expanding global cooperation with profound socioeconomic and ecological implications. As China and associated countries are developing specific policies to implement the initiative, it is important to analyze and integrate major relevant issues. In this article, we discuss several major challenges facing the Belt and Road region: complex natural features, mismatched resources, shared ecological issues, and diverse socioeconomic conditions. To meet the challenges, we apply the integrated framework of telecoupling (socioeconomic and environmental interactions over distances) and propose to enhance infrastructure connection, transboundary actions, scientific and cultural exchanges, and institutional innovations within the Belt and Road region; and collaborate with more international organizations and countries beyond the Belt and Road region for a prosperous and sustainable world.
Weakly self‐reactive T‐cell clones can homeostatically expand when present at low numbers
Authors: Vrisekoop Nienke , Artusa Patricio , Monteiro Joao P. , Mandl Judith N.
Published: October 2016

T‐cell division is central to maintaining a stable T‐cell pool in adults. It also enables T‐cell expansion in neonates, and after depletion by chemotherapy, bone marrow transplantation, or infection. The same signals required for T‐cell survival in lymphoreplete settings, IL‐7 and T‐cell receptor (TCR) interactions with self‐peptide MHC (pMHC), induce division when T‐cell numbers are low. The strength of reactivity for self‐pMHC has been shown to correlate with the capacity of T cells to undergo lymphopenia‐induced proliferation (LIP), in that weakly self‐reactive T cells are unable to divide, implying that T‐cell reconstitution would significantly skew the TCR repertoire toward TCRs with greater self‐reactivity and thus compromise T‐cell diversity. Here, we show that while CD4+ T cells with low self‐pMHC reactivity experience more intense competition, they are able to divide when present at low enough cell numbers. Thus, at physiological precursor frequencies CD4+ T cells with low self‐pMHC reactivity are able to contribute to the reconstitution of the T‐cell pool.
Impact of Infinite Thin Flame Approach on the Evaluation of Flame Speed using Spherically Expanding Flames
Authors: Zhang Feichi , Baust Tobias , Zirwes Thorsten , Denev Jordan , Habisreuther Peter , Zarzalis Nikolaos , Bockhorn Henning
Published: October 2016

Combustion is an important part of most current and future overall energy‐conversion systems, especially if using renewable fuels in energy‐storage concepts. Therefore, the laminar flame speed, which is a key parameter for the design of combustion systems, needs to be known for a growing multitude of different thermodynamic conditions and fuels. The spherically expanding flame method is one of the few techniques that enables the flame speed to be measured under particular conditions such as elevated pressure and temperature as well as under turbulent conditions, which are important for energy‐conversion applications. The radius of a spherically propagating flame is tracked and used for evaluation of the flame speed. Usually, the flame is assumed to be infinitely thin. To assess the influence of this assumption, direct numerical simulations were conducted for the experimental setup and compared with measurements and correlations from the literature. The flame speed determined by the consumption rate of fuel, which takes a finite thickness of the flame into account, was found to be always larger than the flame speed computed by assuming an infinitely thin flame. The difference between these flame speeds was observed to be as large as approximately 10–20 % in the evaluation range of the measured flame radii, which decreases with growing flame radius. This gives rise to the discrepancies in the flame speeds obtained from different measurement methods. An analytical estimation for this difference was developed as a function of the flame radius, which showed quantitatively good agreement with the simulation results and may be used for experimental validations of the flame speed. Both premixed H2/air and CH4/air flames with equivalence ratios ranging from lean to rich conditions were studied.
Thermodynamic analysis and fluid selection for hydraulic retarder waste heat organic rankine cycle
Authors: Chen Ming , Guo Xuexun , Tan Gangfeng , Fang Zhigang
Published: October 2016

An ORC (Organic Rankine Cycle) system driven by hydraulic retarder waste heat oil source is investigated in this study. The main purpose is to identify the appropriate organic working fluid in consideration of the thermodynamic properties and evaporator dimension requirements. In addition, six working fluids including dry and isentropic fluid are used as the candidates in this article. Based on a specified condition, thermal efficiency and expansion ratio flexibility in the operating condition of a wide evaporating pressure and condensing temperature range, exergy efficiency and exergy destruction rate, evaporator heat transfer, and evaporator heat transfer area are chosen as the evaluation criteria to select the optimal working fluid. The results indicate that R245ca, R265mfc, and R123 occupy a larger coverage area as for the high thermal efficiency region, meaning that the operating conditions are more flexible for these fluids in the real vehicle application. Also, a same behavior is presented by the expansion ratio results. Besides, the evaporator heat transfer areas for R245fa and R245ca are the smallest, the maximum areas for which are just 2.59 m2 and 3.22 m2, respectively. Consequently, the optimal working fluid for the hydraulic retarder ORC system turns out to be R245ca. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 548–556, 2017
Macroinvertebrate assemblages in relation to environments in the dongting lake, with implications for ecological management of river‐connected lakes affected by dam construction
Authors: Pan Baozhu , Wang Haijun , Li Zhiwei , Ban Xuan , Liang Xiaomin , Wang Hongzhu
Published: October 2016

The Dongting Lake, a river‐connected lake, plays a vital role in people's living, agricultural production, and ecological security of the Yangtze River basin. A systematic investigation of macroinvertebrates was conducted in the Dongting Lake during May 2004 ‐ January 2005. Altogether 65 taxa belonging to 27 families and 53 genera were identified. The annual average density and biomass of total macroinvertebrates were 265 ind/m2 and 2.40 g dry mass/m2, respectively. It is demonstrated that seasonal variation existed in environmental factors structuring macroinvertebrate assemblages of the Dongting Lake. Hydrological parameters (i.e., flow velocity, water depth) were the driving factors for macroinvertebrate assemblages in spring and summer, whereas the concentrations of water nutrients (i.e., phytoplankton chlorophyll a, total dissolved phosphorus) played the leading role in governing macroinvertebrate assemblages in autumn and winter. After operation of the Three Gorges Dam in 2009, the Dongting Lake may be confronted with the threat of species diversity declining and assemblage structure changing. Thus, ecological restoration measures shall be put forward. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 914–920, 2017
Differences in Cortisol Awakening Response between Binge‐Purging and Restrictive Patients with Anorexia Nervosa
Authors: Monteleone Alessio Maria , Monteleone Palmiero , Marciello Francesca , Pellegrino Francesca , Castellini Giovanni , Maj Mario
Published: October 2016

Malnutrition and childhood trauma were shown to affect in opposite way the cortisol awakening response (CAR) of patients with anorexia nervosa (AN). To assess the influence of binge‐purging behaviour on the CAR of AN patients, we measured the CAR of restrictive AN (ANR) or binge‐purging AN (ANBP) patients without history of childhood maltreatment. Seventeen ANBP women, 18 ANR women and 42 healthy women collected saliva samples at awakening and after 15, 30 and 60 min, and filled in the Eating Disorder Inventory‐2 (EDI‐2). ANR and ANBP patients exhibited a CAR significantly higher than healthy women. Moreover, the CAR of ANBP women was even higher than that of ANR women and positively correlated with the bulimia subitem scores of the EDI‐2. Present findings show, for the first time, differences in the CAR between ANBP and ANR subtypes, which may suggest a possible connection between the HPA axis functioning and binge‐purging. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.
Marine redox variations during the Ediacaran–Cambrian transition on the Yangtze Platform, South China
Authors: Zhai Lina , Wu Chaodong , Ye Yuntao , Zhang Shuichang , An Zhengze
Published: October 2016

The widely developed black shales on the Yangtze Platform recorded palaeoceanographic environment information during the Ediacaran–Cambrian transition. This paper describes an integrated geochemical study of rare earth elements (REEs), redox‐sensitive trace elements (RSTEs), and total organic carbon (TOC) contents in Ediacaran–Cambrian black shales at Daotuo, northeastern Guizhou Province, South China. Integrated RSTE data from the Daotuo area, in combination with previously published Fe speciation and Mo‐based proxies from another six sections (Shatan, Jiulongwan, Zhongling, Yangjiaping, Longbizui and Wuhe), suggest three major periods of water euxinia during the Ediacaran–Cambrian transition. Under these conditions, organic matter and RSTEs experienced various levels of enrichment in the black shales, especially in the lower Jiumenchong Formation. Given the patterns of Mo‐U covariations, metal‐oxyhydroxide particulate shuttles may have operated during the black shale deposition of the Doushantuo Formation (Member II) at Daotuo. Conspicuously, the upper slope water was oxic‐dysoxic during the earliest Cambrian, as determined by the REE, RSTE data and sedimentological characteristics of the Liuchapo Formation and the basal Jiumenchong Formation. The generally low RSTE concentrations in the Bianmachong Formation black shales (Cambrian Series 2, end of Stage 3) suggest a persistently oxic water column in upper slope settings. The coincidence between the marine oxygenation and the development of the ecosystem likely indicates the galvanizing effects of enhanced oxygen and biological element content on the fauna during the Ediacaran–Cambrian transition. Copyright © 2016 John Wiley & Sons, Ltd.
Benchmarking of density functionals for a soft but accurate prediction and assignment of 1H and 13C NMR chemical shifts in organic and biological molecules
Authors: Benassi Enrico
Published: October 2016

A number of programs and tools that simulate 1H and 13C nuclear magnetic resonance (NMR) chemical shifts using empirical approaches are available. These tools are user‐friendly, but they provide a very rough (and sometimes misleading) estimation of the NMR properties, especially for complex systems. Rigorous and reliable ways to predict and interpret NMR properties of simple and complex systems are available in many popular computational program packages. Nevertheless, experimentalists keep relying on these “unreliable” tools in their daily work because, to have a sufficiently high accuracy, these rigorous quantum mechanical methods need high levels of theory. An alternative, efficient, semi‐empirical approach has been proposed by Bally, Rablen, Tantillo, and coworkers. This idea consists of creating linear calibrations models, on the basis of the application of different combinations of functionals and basis sets. Following this approach, the predictive capability of a wider range of popular functionals was systematically investigated and tested. The NMR chemical shifts were computed in solvated phase at density functional theory level, using 30 different functionals coupled with three different triple–ζ basis sets. © 2016 Wiley Periodicals, Inc.
Minding the Dreamer Within: An Experimental Study on the Effects of Enhanced Dream Recall on Creative Thinking
Authors: Sierra‐Siegert Mauricio , Jay Emma‐Louise , Florez Claudia , Garcia Ana Esther
Published: October 2016

Several studies have found an association between frequency of dream recall and creativity. We tested the hypothesis that training individuals to increase dream recall by means of a daily dream log would increase scores on the Torrance Test of Creative Thinking (TTCT). One hundred twenty‐five participants completed a baseline measure of creativity (TTCT, figural version) as well as of dream recall, dissociation, thinness of psychological boundaries, mindful‐attention awareness, and well‐being. Participants were randomly allocated to two groups: the experimental group (n = 55) received a daily dream log; while the control group (n = 32) received a similarly phrased log registering memories of a vivid episode from the previous day. After 27 days, all participants completed follow‐up measurements identical to those at baseline. A non‐randomized non‐intervention group (n = 35) was used to test for practice effects on the TTCT. There was significant selective increase for the “creative strengths” component, which was only observed in the experimental group. There were significant correlations between creativity and dissociation as well as between creativity and thinness of psychological boundaries. Enhanced dream recall through daily dream logging fosters aspects of creativity. Associations between creativity, dissociation, and thinness of boundaries, suggest that increased awareness to dreams increases creativity through a “loosening” of stereotyped thinking pattern.
Miniaturized pipette‐tip‐based electrospun polyacrylonitrile nanofibers for the micro‐solid‐phase extraction of nitro‐based explosive compounds
Authors: Tavengwa Nikita Tawanda , Nyamukamba Pardon , Cukrowska Ewa , Chimuka Luke
Published: October 2016

In this study, a self‐assembly of miniaturized pipette‐tip‐based solid‐phase extraction for the simultaneous extraction of nitroaromatic compounds was developed, with electrospun polyacrylonitrile nanofibers used as sorbents. The electrospun polyacrylonitrile nanofibers were characterized by scanning electron microscopy, FTIR analysis and surface area analysis. Good linearities for the four nitroaromatic compounds (2,6‐dinitrotoluene, 2‐nitrotoluene, 3‐nitrotoluene, and 4‐nitrotoluene) were obtained in a range of 250–1000 μg/L with coefficients of determination > 0.99. The limits of detection of these analytes were between 21 and 38 μg/L. The results showed that the pipette‐tip‐based solid‐phase extraction was effective in extracting nitrotoluenes in the pH regime of environmental interest (≈ 6). The investigation also revealed that the optimum mass of electrospun polyacrylonitrile nanofibers sorbent was 15 mg and 20 aspirating/dispensing cycles gave the maximum recovery of nitrotoluenes with 200 μL acetonitrile as the best eluting solvent. Moreover, the performance of the present method was studied for the extraction and determination of nitroaromatic compounds in real environmental water samples and good recoveries ranging from 70 to 115% were found, and respective relative standard deviations of <12% were obtained.
Metabolomics method based on ultra high performance liquid chromatography with time‐of‐flight mass spectrometry to analyze toxins in fresh and dried toad venom
Authors: Ma Hongyue , Niu Huixia , Cao Qin , Zhou Jing , Gong Yan , Zhu Zhenhua , Lv Xiang , Di Liuqing , Qian Dawei , Wu Qinan , Duan Jin'ao
Published: October 2016

Drying is a critical step to prolong the storage time in natural medicine processing but it changes the chemical characteristics of the product. In this study, research was performed to characterize the metabolomic changes in toad venom induced by vacuum‐drying at 60°C and air‐drying at room temperature by ultra high performance liquid chromatography coupled with pattern recognition approaches. In total 52 metabolites, down‐regulated or up‐regulated, were identified as potential chemical markers. Compared with fresh toad venom, vacuum‐drying at 60°C succeeded in raising the conjugated‐type bufadienolide content significantly, while the content of free‐type bufadienolides were slightly reduced. On the other hand, toad venom air‐dried at room temperature presented a relatively low amount of bufadienolides compared with fresh venom. For example, the content of several known anti‐tumor components (gamabufotalin, bufotalin, cinobufagin, etc.) were significantly reduced. The 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide bioassay further showed that venom air‐dried at room temperature had weaker anti‐tumor activity on human hepatocellular carcinoma SMMC‐7721 proliferation in vitro than samples vacuum‐dried at 60°C. These results showed that the great metabolomic changes of toad venom occurred during the drying process, suggesting that a proper drying procedure is important for sustaining the chemical quality of natural medicines.
Optimal anesthetic regimen for ambulatory laser microlaryngeal surgery
Authors: Huh Hyub , Park Seol Ju , Lim Hyong Hwan , Jung Kwang Yoon , Baek Seung‐Kuk , Yoon Seung Zhoo , Lee Hye Won , Lim Hye Ja , Cho Jang Eun
Published: October 2016

Objectives/Hypothesis

Laser microlaryngeal surgery (LMS) is a short operation requiring brief and intense paralysis. Adequate muscle relaxation and rapid recovery of neuromuscular function are essential for improving surgical conditions and reducing the incidence of complications during LMS. However, the ideal muscle relaxant with a rapid onset and short duration of action is not yet available. Rocuronium has rapid onset at higher doses, but with a prolonged duration of action. Sugammadex is a selective relaxant‐binding agent that allows for rapid reversal of rocuronium‐induced neuromuscular blockade. This study aimed to compare the surgical conditions and anesthesia time between two combinations of neuromuscular blocker and reversal agent, rocuronium‐sugammadex (R‐S) and succinylcholine‐cisatracurium‐pyridostigmine (S‐C‐P), and propose an optimal anesthetic regimen for improving the surgical conditions in LMS patients.

Study Design

Prospective, randomized, double‐blinded clinical study.

Methods

Patients in the R‐S group received 1 mg/kg rocuronium bromide, whereas those in the S‐C‐P group received 1 mg/kg succinylcholine. After endotracheal intubation, 0.08 mg/kg cisatracurium was injected in S‐C‐P patients. After the procedure, R‐S patients received 2 mg/kg sugammedex, whereas S‐C‐P patients received 0.2 mg/kg pyridostigmine plus 10 μg/kg atropine.

Results

In the R‐S group, surgical condition scores were significantly higher and anesthesia time was significantly shorter. The use of additive neuromuscular blocking agents was significantly higher in the S‐C‐P group.

Conclusions

Muscle relaxation with rocuronium and reversal with sugammadex resulted in better surgical conditions and a shorter anesthesia time in patients undergoing LMS when compared to the S‐C‐P regimen.

Level of Evidence

1b Laryngoscope, 127:1135–1139, 2017
Jumping and overcoming diffusion limitation of nutrient uptake in the photosynthetic ciliate Mesodinium rubrum
Authors: Jiang Houshuo , Johnson Matthew D.
Published: October 2016

Fast, frequent, and spontaneous jumping by the photosynthetic ciliate Mesodinium rubrum is highly adaptive for overcoming diffusion limitation of nutrient uptake. Using high‐speed, high‐magnification, digital imaging, jumping behaviors of an Antarctic and temperate North American strain of M. rubrum were investigated. Both strains displayed multiple‐beat long jumps, wherein maximum jump speeds and total jump durations varied significantly with strain, temperature, and illumination. However, jump distances were surprisingly similar with means approximating six body lengths, which were just above the thickness of nutrient diffusive boundary layer surrounding the cell. Total jump durations scaled by diffusion time scale were < 1 for almost all observed jumps. Moreover, jump distances and square roots of pre‐jump residence times were linearly correlated. Thereby, jumping by M. rubrum is physically constrained by the small‐scale advection‐diffusion physics of the cell's immediately surrounding water. Additionally, to achieve similar jump distances as the temperate strain at warm temperature, the Antarctic strain lengthened each beat cycle of cilia to kinematically compensate low jump speed at cold temperature, but the ratio of power to recovery stroke duration (∼ 6 : 1) remained unchanged with temperature. As further shown by computational fluid dynamics simulations driven by empirical data, multiple‐beat long jumping allows both strains to completely detach the boundary layer and achieve similar Sherwood numbers significantly > 1, despite substantially different jumping kinematics. All these results support the notion that jumping is an essential behavior for M. rubrum to enhance nutrient uptake, and help to explain their high photosynthetic rates and ecological success.
Stream tracer breakthrough curve decomposition into mass fractions: A simple framework to analyze and compare conservative solute transport processes
Authors: Wlostowski Adam N. , Gooseff Michael N. , Bowden William B. , Wollheim Wilfred M.
Published: October 2016

Ecological functions are coupled to the physical transport of water and solutes in streams. Transport of conservative tracers in lotic systems is subject to the processes of advection, dispersion, transient storage, and mass loss to groundwater. Stream tracer experiments and the simulation of observed tracer breakthrough curve (BTC) data with 1‐D numerical transient storage models (TSMs) are commonly used to quantify these processes. Results from TSMs can be useful, but issues related to model appropriateness and parameter identifiability suggest a need for conceptually simpler approaches to BTC analyses. We present a new approach to analyze BTCs to quantify the amount of stream water transported by each dominant process. BTCs are analyzed to parse the total quantity of injected tracer mass into three dominant process domains: advection and dispersion, transient storage, and gross loss of tracer. This method can be used to quantify the relative influence of transport processes within, and among streams, and estimate the proportion of stream water associated with each mode of transport. As proof of concept, we apply this approach to conservative tracer injections on two streams of contrasting morphology. Application of this method indicates that transport of injected solute mass in an alluvial stream is dominated by advection and dispersion, relative to a beaded, peat‐bottomed stream, where more tracer mass transport was found to be associated with longer timescale transient storage processes. This approach provides a simple, inexpensive, and useful quantification of dominant transport processes and provides an additional tool for analyzing experimental BTC data.
Modified approach for endoscopic harvest of the latissimus dorsi free flap with CO2 insufflation and standard laparoscopic equipment
Authors: Kiiski Juha , Kaartinen Ilkka , Kotaluoto Sannamari , Kuokkanen Hannu
Published: October 2016

Objective

The latissimus dorsi (LD) muscle flap is frequently used for free tissue transfer to reconstruct large defects of the extremities. As a free flap, the LD also can be harvested as a muscle‐sparing flap (MS‐LD), preserving the innervation and insertion of the remaining muscle. Conventional harvesting of the LD flap, however, results in a long scar on the lateral back. Harvesting using an endoscopic approach minimizes donor site morbidity. We present our modified endoscopic technique with CO2 insufflation and standard endoscopic instruments for harvesting the LD or MS‐LD muscle flap.

Patients and methods

Ten patients (mean age 43 years, range 22–66) underwent endoscopically harvested LD or MS‐LD free‐flap reconstruction for upper and lower extremity defects. Harvesting required only a short (3–5 cm) incision in the axilla for dissection of the vascular pedicle and the motor nerve, and the remainder of the dissection was performed endoscopically with CO2 insufflation. Dissection was achieved through three of four 5‐mm ports and 30° view angle optics.

Results

Six of the flaps were MS‐LD flaps. The largest flap size was 18 × 16 cm. Mean flap harvest time was 164 min (range 105–270 min). One total flap was lost 3 days postoperatively due to anastomotic thrombosis in a trauma patient who was later diagnosed with hypercoagulopathy. No donor site scar or wound complications were observed during the follow‐up (20.1 months).

Conclusions

Endoscopic harvesting of an LD muscle free flap with CO2 insufflation and standard laparoscopic equipment is a feasible option for free‐flap reconstruction. © 2016 Wiley Periodicals, Inc. Microsurgery 37:383–387, 2017.
Parameterization of spectral baseline directly from short echo time full spectra in 1H‐MRS
Authors: Lee Hyeong Hun , Kim Hyeonjin
Published: October 2016

Purpose

To investigate the feasibility of parameterizing macromolecule (MM) resonances directly from short echo time (TE) spectra rather than pre‐acquired, T1‐weighted, metabolite‐nulled spectra in 1H‐MRS.

Methods

Initial line parameters for metabolites and MMs were set for rat brain spectra acquired at 9.4 Tesla upon a priori knowledge. Then, MM line parameters were optimized over several steps with fixed metabolite line parameters. The proposed method was tested by estimating metabolite T1. The results were compared with those obtained with two existing methods. Furthermore, subject‐specific, spin density‐weighted, MM model spectra were generated according to the MM line parameters from the proposed method for metabolite quantification. The results were compared with those obtained with subject‐specific, T1‐weighted, metabolite‐nulled spectra.

Results

The metabolite T1 were largely in close agreement among the three methods. The spin density‐weighted MM resonances from the proposed method were in good agreement with the T1‐weighted, metabolite‐nulled spectra except for the MM resonance at ∼3.2 ppm. The metabolite concentrations estimated by incorporating these two different spectral baselines were also in good agreement except for several metabolites with resonances at ∼3.2 ppm.

Conclusion

The MM parameterization directly from short‐TE spectra is feasible. Further development of the method may allow for better representation of spectral baseline with negligible T1‐weighting. Magn Reson Med 78:836–847, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Total variation–based method for generation of intravoxel incoherent motion parametric images in MRI
Authors: Lin Chieh , Shih Yi‐Yu , Huang Siao‐Lan , Huang Hsuan‐Ming
Published: October 2016

Purpose

Total variation (TV) method has been used widely for image restoration and reconstruction. In this work, we propose a TV‐based algorithm for parametric image generation in intravoxel incoherent motion (IVIM) diffusion‐weighted magnetic resonance imaging (DW‐MRI).

Methods

We used simulated and real data to investigate whether the proposed TV‐based method can provide reliable parametric images. Parametric images of IVIM parameters including perfusion fraction (PF), diffusion coefficient (D), and pseudo‐diffusion coefficient (D*) were estimated using DW‐MRI data and TV through fitting the IVIM model. The Levenberg‐Marquardt (LM) method, which has often been used in the context of IVIM analysis, was employed as the standard method for comparison of the resulting parametric images.

Results

The simulation results show that the proposed method outperforms the LM algorithm in terms of precision, providing a 40–81%, 90–93%, and 68–84% improvement for PF, D and D*, respectively, at signal‐to‐noise ratio (SNR) of 30. For real data, the proposed method showed an average five‐fold, three‐fold, and four‐fold improvement in the SNR for PF, D and D*, respectively.

Conclusion

We introduced the use of TV to produce parametric images, and demonstrated that the proposed TV‐based method is effective in improving the parametric image quality. Magn Reson Med 78:1383–1391, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Quantification of glutathione in the human brain by MR spectroscopy at 3 Tesla: Comparison of PRESS and MEGA‐PRESS
Authors: Sanaei Nezhad Faezeh , Anton Adriana , Parkes Laura M. , Deakin Bill , Williams Stephen R.
Published: October 2016

Purpose

Glutathione (GSH) is an important intracellular antioxidant in the brain. A number of studies report its measurement by localized 1H spectroscopy using PRESS and STEAM. This study evaluates the reliability and accuracy of GSH measurements from PRESS at 3 Tesla (T) and compares the results to those obtained with MEGA‐PRESS.

Methods

Phantoms containing brain metabolites, identical except for variable GSH concentration between 0 and 24 mM, were scanned using PRESS (echo time (TE) = 35 ms) and MEGA‐PRESS (optimized TE = 130 ms) at 3 T. Spectra of the anterior cingulate cortex and occipital cortex in seven healthy volunteers were also acquired.

Results

Phantom GSH concentrations from 0 to 3mM were unreliably quantified using PRESS, although at 4 mM and above there was a linear relationship between measured and true concentrations (R2 = 0.99). Using MEGA‐PRESS, there was no signal detected at 0 mM GSH, plus a linear relationship (R2 = 0.99) over the full range from 0–24 mM. In brain, concentrations calculated from MEGA‐PRESS and PRESS were significantly different in occipital cortex (P < 0.001). Moreover, only MEGA‐PRESS reported significant differences in GSH between the two brain regions (P = 0.003).

Conclusion

Due to uncertainties in GSH quantification raised by the study, the authors conclude that physiological concentrations (<4 mM) of GSH cannot be reliably quantified from PRESS (TE = 35 ms) spectra at 3 T. Magn Reson Med 78:1257–1266, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Selective arterial spin labeling in conjunction with phase‐contrast acquisition for the simultaneous visualization of morphology, flow direction, and velocity of individual arteries in the cerebrovascular system
Authors: Lindner Thomas , Larsen Naomi , Jansen Olav , Helle Michael
Published: October 2016

Purpose

In various cerebrovascular diseases the visualization of individual arteries and knowledge about their hemodynamic properties, like flow velocity and direction, can become important for an accurate diagnosis. Magnetic resonance angiography methods are intended to acquire this information, but often a single acquisition is not sufficient to retrieve all of this desired information.

Methods

Using selective arterial spin labeling (ASL) methods, a single artery of interest can be tagged and visualized, whereas quantitative information about hemodynamics can be retrieved using phase‐contrast techniques that are often limited regarding their selectivity. In this study, a method that allows for velocity mapping of individual arteries by incorporating phase‐contrast preparation into selective ASL angiography measurements is presented. Several postprocessing steps are required to generate velocity and directional‐encoded maps of selected arteries from the data acquired in a single scan.

Results

The method was successfully evaluated in healthy volunteers, and a first application in two selected patients is presented. In one patient, an aneurysm of the middle cerebral artery is investigated, and in the second patient it is used to visualize an arterio‐venous malformation.

Conclusion

Selective ASL imaging in conjunction with phase‐contrast acquisition allows for investigating hemodynamic properties of individual arteries. Magn Reson Med 78:1469–1475, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
The effect of tuning chemical structure on the open‐circuit voltage and photovoltaic performance of narrow band‐gap polymers
Authors: Li Huan , Zhao Yifan , Zhu Xiangwei , Xia Benzheng , Lu Kun , Yuan Liu , Zhang Jianqi , Guo Xuefeng , Yan Wei , Wei Zhixiang
Published: October 2016

Most of the narrow band‐gap polymers exhibit low open‐circuit voltage (Voc) which limits the further improvement of photovoltaic performance. How to improve the Voc through fine tuning of the chemical structure is a significant project that worth exploring. As a big and strong electron accepting unit, fluorinated‐quinoxaline based copolymers always show a narrow band gap and broad absorption which makes it a good template to study the changes of Voc through structure tuning. In this work, the effect of the subtle chemical structure modulation of polymer side chains and main chain on the Voc and photovoltaic performance was investigated. The Voc was adjusted effectively, and the power conversion efficiency (PCE) also was improved simultaneously. Although the PCE was not high enough as those high‐performance polymers reported at present, the result indicates that fine tuning of chemical structure is an effective way to improve Voc and photovoltaic performance for narrow band‐gap polymers. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 699–706
Synergistic CO2 conversion by hybridization of dielectric barrier discharge and solid oxide electrolyser cell
Authors: Mori Shinsuke , Tun Lin Lin
Published: October 2016

Hybrid reactor of Dielectric Barrier Discharge (DBD) and Solid Oxide Electrolyser Cell (SOEC) was fabricated and CO2 decomposition characteristics were investigated. For the case of the DBD reactor alone, the CO2 conversion saturates with residence time. In contrast, the saturation is not observed for the case of the hybrid system where CO2 conversion increases monotonically with increasing residence time. This is because the reverse reaction to regenerate the CO2 in plasma is suppressed by the oxygen removal by SOEC in hybrid system and consequently CO2 decomposition reaction proceeds irreversibly. We have examined the experimental results by analytical modeling and reaction mechanism for the CO2 decomposition in the hybrid reactor of DBD and SOEC is deduced. The time‐dependent CO2 conversion for the only plasma reactor and hybrid reactor can be reproduced by a reversible and irreversible first‐order reaction model, respectively. The analytical model can also reproduce the dependence of CO2 conversion on the plasma input power very well. Interestingly, not only the reverse reaction rate but also the forward dissociation reaction rate is reduced by the SOEC in the case of hybrid reactor. The analytical modeling suggests that CO2 decomposition in the conventional DBD plasma reactor proceeds not merely by direct electron impact dissociation but also by reaction with reactive oxygen.
Goodness‐of‐fit test for monotone proportional subdistribution hazards assumptions based on weighted residuals
Authors: Boher Jean‐Marie , Filleron Thomas , Giorgi Roch , Kramar Andrew , Cook Richard J.
Published: October 2016

Recently goodness‐of‐fit tests have been proposed for checking the proportional subdistribution hazards assumptions in the Fine and Gray regression model. Zhou, Fine, and Laird proposed weighted Schoenfeld‐type residuals tests derived under an assumed model with specific form of time‐varying regression coefficients. Li, Sheike, and Zhang proposed an omnibus test based on cumulative sums of Schoenfeld‐type residuals. In this article, we extend the class of weighted residuals tests by allowing random weights of Schoenfeld‐type residuals at ordered event times. In particular, it is demonstrated that weighted residuals tests using monotone weight functions of time are consistent against monotone proportional subdistribution hazards assumptions. Extensive Monte Carlo studies were conducted to evaluate the finite‐sample performance of recent goodness‐of‐fit tests. Results from simulation studies show that weighted residuals tests using monotone random weight functions commonly used in non‐proportional hazards regression settings tend to be more powerful for detecting monotone departures than other goodness‐of‐fit tests assuming no specific time‐varying effect or misspecified time‐varying effects. Two examples using real data are provided for illustrations. Copyright © 2016 John Wiley & Sons, Ltd.
Phenyl (2‐quinolyl) methanol: A Valuable Reagent for Metal‐Free Reduction of Aromatic Nitro Compounds and Imines
Authors: Giomi Donatella , Alfini Renzo , Ceccarelli Jacopo , Salvini Antonella , Brandi Alberto
Published: October 2016

Phenyl (2‐quinolyl) methanol (PQM) behaves as a new efficient reagent for metal‐free reduction of nitro aromatic and heteroaromatic compounds. The reduction proceeds in mild reaction conditions affording anilines in good yields. Phenyl (2‐quinolyl) ketone (PQK), the oxidation product of PQM, can be quantitatively recovered and reused after reduction making sustainable the overall process. The reduction outcome changes with electron‐deficient nitroarenes that afford the expected anilines and electron‐rich nitro compounds that give reductive amination products via reduction of imines formed by condensation of nucleophilic anilines with PQK. These multicomponent reactions were observed also with activated aldehydes and in the presence of acrylates for the synthesis of β‐anilino esters. The synthetic value of the new metal‐free reducing agent, unmatched by the well‐known Hantzsch ester, has been exploited in metal‐free Reissert indole and Friedländer quinoline syntheses.
Relational job characteristics and well‐being: A study among Portuguese and Brazilian hospital nurses
Authors: Santos Alda , Castanheira Filipa , Chambel Maria José , Amarante Michael Vieira , Costa Carlos
Published: October 2016

Nurse well‐being is a crucial factor in the quality of care given to patients and in patient safety. The purpose of this study was to investigate the relationships between the psychological effects of relational job characteristics (PERJCs) and indicators of well‐being in hospital nurses. The data for this correlational study were collected from an online survey responded to by a sample of 620 hospital nurses (335 Portuguese and 285 Brazilian). Statistical procedures included structural equation modeling and multigroup analysis. A full mediation model was supported by data analysis, in which work‐related well‐being (i.e., engagement and burnout) explained the relationships between hospital nurses' perceived social worth and their context‐free well‐being. Moreover, in the Portuguese sample, the perceived social impact on client lives and the affective commitment to clients were indirectly related to the context‐free well‐being of nurses, through work engagement. Practical implications are presented in order to foster the PERJCs, thus contributing to nurse well‐being.
Synthesis, Structures, and Properties of Cadmium(II) and Nickel(II) Coordination Polymers Based on a 4,4′‐Biphenyl‐Containing Ligand and Aliphatic Carboxylic Acids
Authors: Zhang Xu , Blatov Vladislav A. , Zhao Yan‐Qin , Hao Zeng‐Chuan , Cui Guang‐Hua
Published: October 2016

The coordination polymers [Cd2(bbmb)2(L1)(HL1)0.5(H2O)]n (1), [Cd2(bbmb)2(L2)2(H2O)·(H2O)]n (2), and [Ni(bbmb)2(L3)]n (3), were synthesized by the hydrothermal reaction of 4,4′‐bis(benzimidazol‐1‐ylmethyl)biphenyl (bbmb) with CdII/NiII ions in the presence of three flexible aliphatic acids [tricarballylic acid (H3L1), succinate (H2L2), and adipate (H2L3)]. Complexes 1–3 were structurally characterized by elemental analysis, IR spectroscopy and single‐crystal and X‐ray powder diffraction analyses. Complex 1 presents a 3D 3‐nodal (3,4,4)‐connected net with 3,4,4T78 topology, 2 exhibits a 3D network with 66‐dia topology, whereas 3 is a chain structure and further extended by hydrogen bonding interactions to form a 2D supramolecular network. Structural diversity of these complexes indicates that these frameworks could be tuned by the conformation of bbmb ligand and the different coordination modes of the aliphatic carboxylate co‐ligands. The thermal and fluorescence properties, the catalytic activities of complexes 1–3 in a Fenton‐like process were investigated.