bluuebunny/crossref_metadata_2025 huggingface dataset:
A Bifunctional Hybrid Electrocatalyst for Oxygen Reduction and Evolution: Cobalt Oxide Nanoparticles Strongly Coupled to B,N‐Decorated Graphene
Authors: Tong Yun , Chen Pengzuo , Zhou Tianpei , Xu Kun , Chu Wangsheng , Wu Changzheng , Xie Yi
Published: May 2017

The electrocatalyzed oxygen reduction and evolution reactions (ORR and OER, respectively) are the core components of many energy conversion systems, including water splitting, fuel cells, and metal–air batteries. Rational design of highly efficient non‐noble materials as bifunctional ORR/OER electrocatalysts is of great importance for large‐scale practical applications. A new strongly coupled hybrid material is presented, which comprises CoOx nanoparticles rich in oxygen vacancies grown on B,N‐decorated graphene (CoOx NPs/BNG) and operates as an efficient bifunctional OER/ORR electrocatalyst. Advanced spectroscopic techniques were used to confirm formation of abundant oxygen vacancies and strong Co−N−C bridging bonds within the CoOx NPs/BNG hybrid. Surprisingly, the CoOx NPs/BNG hybrid electrocatalyst is highly efficient for the OER with a low overpotential and Tafel slope, and is active in the ORR with a positive half‐wave potential and high limiting current density in alkaline medium.
Tris(perfluortolyl)boran – eine Bor‐Lewis‐Supersäure
Authors: Körte Leif A. , Schwabedissen Jan , Soffner Marcel , Blomeyer Sebastian , Reuter Christian G. , Vishnevskiy Yury V. , Neumann Beate , Stammler Hans‐Georg , Mitzel Norbert W.
Published: May 2017

Tris[tetrafluor‐4‐(trifluormethyl)phenyl]boran (BTolF) wurde durch Reaktion von Bortribromid mit tetramerem F3CC6F4‐CuI hergestellt. Letzteres wurde aus F3CC6F4MgBr und Kupfer(I)‐bromid erzeugt. Die mittels der Gutmann‐Beckett‐Methode gemessenen und aus berechneten Fluoridionenaffinitäten abgeschätzte Lewis‐Aciditäten von BTolF sind 9 bzw. 10 % höher als die von Tris(pentafluorphenyl)boran (BCF) und sogar höher als die von SbF5. Die Molekülstrukturen von BTolF und BCF wurden mithilfe von Elektronenbeugung in der Gasphase, die von BTolF auch mittels Einkristallröntgenstrukturanalyse bestimmt.
A Long‐Life Lithium–Air Battery in Ambient Air with a Polymer Electrolyte Containing a Redox Mediator
Authors: Guo Ziyang , Li Chao , Liu Jingyuan , Wang Yonggang , Xia Yongyao
Published: May 2017

Lithium–air batteries when operated in ambient air generally exhibit poor reversibility and cyclability, because of the Li passivation and Li2O2/LiOH/Li2CO3 accumulation in the air electrode. Herein, we present a Li–air battery supported by a polymer electrolyte containing 0.05 m LiI, in which the polymer electrolyte efficiently alleviates the Li passivation induced by attacking air. Furthermore, it is demonstrated that I−/I2 conversion in polymer electrolyte acts as a redox mediator that facilitates electrochemical decomposition of the discharge products during recharge process. As a result, the Li–air battery can be stably cycled 400 times in ambient air (relative humidity of 15 %), which is much better than previous reports. The achievement offers a hope to develop the Li–air battery that can be operated in ambient air.
Biofunctional Microgel‐Based Fertilizers for Controlled Foliar Delivery of Nutrients to Plants
Authors: Meurer Richard A. , Kemper Steffen , Knopp Sandra , Eichert Thomas , Jakob Felix , Goldbach Heiner E. , Schwaneberg Ulrich , Pich Andrij
Published: May 2017

Foliar application of micronutrients (e.g. Fe3+) onto plants over an extended time is challenging and often not possible due to insufficient rainfastness. Smart delivery systems which enable micronutrient release over several weeks would offer innovative and sustainable options to improve plant health and food production. Herein, we report a novel foliar fertilizer delivery system based on functional pH‐responsive biohybrid microgels that have orthogonal functionality as carriers of micronutrients and employ peptides (termed anchor peptides) as foliar adhesion promoters. The anchor peptides bind to hydrophobic surfaces and the waxy “islands” of plant leaves. Our system requires no auxiliaries and is loadable, storable, and applicable from aqueous dispersion. We report the synthesis and functionalization of microgels, their loading with Fe3+ ions, and a proof of concept for the biofunctional microgel‐based fertilizer system is demonstrated for iron‐deficient cucumber plants.
Tris(perfluorotolyl)borane—A Boron Lewis Superacid
Authors: Körte Leif A. , Schwabedissen Jan , Soffner Marcel , Blomeyer Sebastian , Reuter Christian G. , Vishnevskiy Yury V. , Neumann Beate , Stammler Hans‐Georg , Mitzel Norbert W.
Published: May 2017

Tris[tetrafluoro‐4‐(trifluoromethyl)phenyl]borane (BTolF) was prepared by treating boron tribromide with tetrameric F3CC6F4‐CuI. The F3CC6F4‐CuI was generated from F3CC6F4MgBr and copper(I) bromide. Lewis acidities of BTolF evaluated by the Gutmann–Beckett method and calculated fluoride‐ion affinities are 9 and 10 %, respectively, higher than that of tris(pentafluorophenyl)borane (BCF) and even higher than that of SbF5. The molecular structures of BTolF and BCF were determined by gas‐phase electron diffraction, that of BTolF also by single‐crystal X‐ray diffraction.
Toward a better understanding of the emulsion polymerization of butadiene. I. Continuous conductivity measurements
Authors: Fadaee Mohammad Mahdi , Farshchi Tabrizi Farshad
Published: May 2017

Continuous conductivity measurements were performed during the batch emulsion polymerization of butadiene along with kinetic and particle size measurements. The critical monomer conversion was obtained around 55% and the rate of polymerization was correlated to the surfactant concentration with an exponent of 0.35 which was not in agreement with the exponent offered by Smith and Ewart. In addition, the evolution of some particle‐related quantities such as particle size and number of particles during the three intervals of the emulsion polymerization and their agreements with Smith‐Ewart mechanism were investigated. The behavior of conductivity in the emulsion polymerization of butadiene normally containing a buffering agent was found to be completely different from the unbuffered one. Comparison of the conductivity profiles with the kinetic and particle‐related quantities represented that the conductivity of the reaction mixture is very sensitive to the changes in the particle size so that any small change in the forms of nucleation, growth, and coagulation is clearly observed in the conductivity profiles. Furthermore, the conductimetric data are capable of determining some important points during the polymerization such as the beginning of the reaction that can be important from the industrial process control point of view. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2017,134, 45262.
Possible Role of the Myelinated Neural Network in the Parietal Peritoneum in Rats as a Mechanoreceptor
Authors: Tanaka Koichi , Kuwahara‐Otani Sachi , Maeda Seishi , Minato Yusuke , Yagi Hideshi
Published: May 2017

A network of myelinated nerve fibers in the peritoneum covers the abdominal wall. We studied the topographic distribution of this network, explored the fibers' destination in the central nervous system, and examined the markers in these fibers in order to identify the nature of the sensation conveyed by the network of nerve fibers in rats. We used Sihler's method, which stains myelinated fibers in whole mount materials, and observed a dense nerve network and endings toward the peritoneal cavity in the peritoneum that covers the abdomen's lateral bulge. We studied the axonal transport of cholera toxin subunit B to investigate the central projections of this network in order to identify its function. After applying the tracer in the peritoneum, we observed many labeled terminals in the medial part of laminae 3–5 of the spinal cord. A small number of labeled terminals was observed in the dorsal nucleus of Clarke and gracile nucleus. Labeled somata were observed in the dorsal root ganglia (DRG). Most (96%) were larger than 35 μm. We performed immunohistochemistry of the abdominal wall, using antiserum against the 200‐kD neurofilament (a marker for mechanosensory neurons). We observed many positive nerve fibers in the peritoneum. Because cell bodies in the DRG were large, their nerve terminals ended in the base of the dorsal horn, which is known to transmit proprioceptive information, and the network possesses the marker for mechanosensitive fibers; therefore, it appears that the myelinated nerve network conveys information about distension and/or contraction of the abdominal wall. Anat Rec, 300:1662–1669, 2017. © 2017 Wiley Periodicals, Inc.
Frontal Sinus Development and Juvenile Age Estimation
Authors: Moore Kaitlin , Ross Ann
Published: May 2017

Assessment of development is an important component of age estimation in juveniles. One area that has not been fully investigated as a possible aging method is the development of the frontal sinus. The frontal sinuses form when the ectocranial table of the frontal bone separates from the endocranial table forming an air pocket in the bone. The endocranial table ceases growth with the brain, while the ectocranial table is displaced anteriorly as the facial bones continue growth. In order to examine growth and the utility of the frontal sinuses for age estimation, 392 radiographs were examined (♀=159 and ♂=233) from the Juvenile Radiograph Database at North Carolina State University and the Patricia Database from Mercyhurst University. The sample included individuals who ranged in age from 0 to 18 years. Anterior view (or AP) radiographs were examined and were grouped based upon the presence or absence of the frontal sinus. Individuals were grouped into four age categories. A one‐way ANOVA was performed to test whether developmental phase was related to age. Results from the ANOVA show that developmental phase is significantly related to age (P <.0001). An ordinal logistic regression was conducted to examine whether developmental phase could be used to predict age. The results of the logistic regression suggest that developmental phase is an accurate indicator of age (P <.0001, df = 1, Chi‐Squared = 537.2428); however, the age ranges can be quite wide and should be utilized alongside other established methods of age estimation. Anat Rec, 300:1609–1617, 2017. © 2017 Wiley Periodicals, Inc.
A novel chemiluminescence sensor for the determination of indomethacin based on sulfur and nitrogen co‐doped carbon quantum dot–KMnO4 reaction
Authors: Hallaj Tooba , Amjadi Mohammad , Manzoori Jamshid L. , Azizi Neda
Published: May 2017

We report on a simple and sensitive sulfur and nitrogen co‐doped carbon quantum dot (S,N‐CQD)‐based chemiluminescence (CL) sensor for the determination of indomethacin. S,N‐CQDs were prepared by a hydrothermal method and characterized by fluorescence spectra, Fourier transform infrared spectroscopy and transmission electron microscopy. To obtain the best CL system for determination of indomethacin, the reaction of S,N‐CQDs with some common oxidants was studied. Among the tested systems, the S,N‐CQD–KMnO4 reaction showed the highest sensitivity for the detection of indomethacin. Under optimum conditions, the calibration plot was linear over a concentration range of 0.1–1.5 mg L−1, with a limit of detection (3σ) of 65 μg L−1. The method was applied to the determination of indomethacin in environmental and biological samples with satisfactory results.
Design and Development of Efficient Bifunctional Catalysts by Tuning the Electronic Properties of Cobalt–Manganese Tungstate for Oxygen Reduction and Evolution Reactions
Authors: Karkera Guruprakash , Sarkar Tanmay , Bharadwaj Mridula Dixit , Prakash Annigere. S.
Published: May 2017

Solid‐state electrochemistry is drawing considerable interest as the interconversion of O2 and water playing an important role in energy conversion and storage technologies. With the aim of developing an efficient bifunctional catalyst by tuning the electronic properties and local structure around the 3d metal in CoWO4, solid solutions of Co1−xMnxWO4 are investigated. Nanocrystalline Co1−xMnxWO4 (x=0 to 1) phases with a unique exposure of low surface energy planes are synthesized by hydrothermal methods. Replacing an optimum amount of Co with Mn to enhance the catalytic activity leads a observation of a negative shift in the Co2+/3+ redox wave and onset of the oxygen evolution reaction (OER), indicating a strong electronic interaction between the two elements. The composition corresponding to Co0.5Mn0.5WO4 has demonstrated great ability to catalyze both the OER and oxygen reduction reaction (ORR) with a combined overpotential of 0.89 V. It exhibited an OER current density of 10 mA cm−2 at an overpotential of 400 mV. Whereas ORR current density of 3 mA cm−2 is reached at a potential of 0.74 V versus reversible hydrogen electrode (RHE). The density functional theory revealed that the substitution of Mn in CoWO4 elevate the 3d metal d band center closer to the Fermi energy and hence ease the electron transfer to facilitate ORR and OER.
N‐Aryl Groups Are Ubiquitous in Cross‐Dehydrogenative Couplings Because They Stabilize Reactive Intermediates
Authors: Tsang Althea S.‐K. , Hashmi A. Stephen K. , Comba Peter , Kerscher Marion , Chan Bun , Todd Matthew H.
Published: May 2017

The mechanism of cross‐dehydrogenative coupling (CDC) reactions has been examined by experimental and computational methods. We provide a rationale for the ubiquity of theN‐aryl group in these reactions. The aryl substituent stabilizes two intermediates and the high‐energy transition state that connects them, which together represent the rate‐determining step. This knowledge has enabled us to predict whether new CDC substrates will react either well or poorly.
Differential Attenuation of NMR Signals by Complementary Ion‐Exchange Resin Beads for De Novo Analysis of Complex Metabolomics Mixtures
Authors: Zhang Bo , Yuan Jiaqi , Brüschweiler Rafael
Published: May 2017

A primary goal of metabolomics is the characterization of a potentially very large number of metabolites that are part of complex mixtures. Application to biofluids and tissue samples offers insights into biochemical metabolic pathways and their role in health and disease. 1D 1H and 2D 13C‐1H HSQC NMR spectra are most commonly used for this purpose. They yield quantitative information about each proton of the mixture, but do not tell which protons belong to the same molecule. Interpretation requires the use of NMR spectral databases, which naturally limits these investigations to known metabolites. Here, a new method is presented that uses complementary ion exchange resin beads to differentially attenuate 2D NMR cross‐peaks that belong to different metabolites. Based on their characteristic attenuation patterns, cross‐peaks could be clustered and assigned to individual molecules, including unknown metabolites with multiple spin systems, as demonstrated for a metabolite model mixture and E. coli cell lysate.
Synthesis of Macro‐Mesoporous MCM‐41 and Its Use in Methylene Blue Adsorption
Authors: Thome Andreas Georg , Harms Corinna , Roessner Frank
Published: May 2017

MCM‐41 was synthesized in the presence of yeast cells (Saccharomyces cerevisiae). The corresponding calcined material was characterized by scanning electron microscopy, X‐ray diffraction, nitrogen sorption, and mercury porosimetry and compared to MCM‐41 silica synthesized in the absence of yeast. The material synthesized with yeast cells showed equally sized ordered mesoporous silica particles arranged around macropores. These macropores are negative replica of the yeast cells. This material has superior methylene blue adsorption properties from aqueous solution in comparison to ordinary MCM‐41.
The prediction of viscous losses and pressure drop in models of the human airways
Authors: Wells Andrew K. , Jones Ian P. , Hamill Ian S. , Bordas Rafel
Published: May 2017

This paper examines the viscous flow resistance in branching tubes as applied to simplified models of the lungs and compares the results of computational fluid dynamics simulations for a range of conditions with measurement data. The results are in good agreement with the available measurement data for both inspiration and expiration. A detailed sensitivity analysis of the dissipation and viscous resistance in a branch then examines the ratio of the viscous resistance to that for a fully developed Poiseuille flow, Z. As other researchers have noted, the calculated resistances give lower values than those from the standard correlation of Pedley et al. The results demonstrate that the resistance is sensitive to the velocity profile upstream of the bifurcations and explain from fluid dynamical considerations the apparent sensitivity of the resistance to the generation number of the branch. The paper also suggests a revised value for the calibration constant in the expression for Z. Finally, a limited set of results are presented for junction losses, and for expiration.
Alcohol consumption and cigarette smoking in combination: A predictor of contralateral breast cancer risk in the WECARE study
Authors: Knight Julia A. , Fan Jing , Malone Kathleen E. , John Esther M. , Lynch Charles F. , Langballe Rikke , Bernstein Leslie , Shore Roy E. , Brooks Jennifer D. , Reiner Anne S. , Woods Meghan , Liang Xiaolin , Bernstein Jonine L. ,   on behalf of the WECARE Study Collaborative Group
Published: May 2017

Alcohol drinking and, to a lesser extent, cigarette smoking are risk factors for a first primary breast cancer. Information on these behaviours at diagnosis may contribute to risk prediction of contralateral breast cancer (CBC) and they are potentially modifiable. The WECARE Study is a large population‐based case‐control study of women with breast cancer where cases (N = 1,521) had asynchronous CBC and controls (N = 2,212), matched on survival time and other factors, had unilateral breast cancer (UBC). Using multivariable conditional logistic regression to estimate rate ratios (RR) and 95% confidence intervals (CI), we examined the risk of CBC in relation to drinking and smoking history at and following first diagnosis. We adjusted for treatment, disease characteristics and other factors. There was some evidence for an association between CBC risk and current drinking or current smoking at the time of first breast cancer diagnosis, but the increased risk occurred primarily among women exposed to both (RR = 1.62, 95% CI 1.24–2.11). CBC risk was also elevated in women who both smoked and drank alcohol after diagnosis (RR = 1.54, 95% CI 1.18–1.99). In the subset of women with detailed information on amount consumed, smoking an average of ≥10 cigarettes per day following diagnosis was also associated with increased CBC risk (RR = 1.50, 95% CI 1.08–2.08; p‐trend = 0.03). Among women with a diagnosis of breast cancer, information on current drinking and smoking could contribute to the prediction of CBC risk. Women who both drink and smoke may represent a group who merit targeted lifestyle intervention to modify their risk of CBC.
Future extreme temperature and its impact on rice yield in China
Authors: Zhang Zhao , Chen Yi , Wang Chenzhi , Wang Pin , Tao Fulu
Published: May 2017

Rice in China is increasingly suffered from extreme temperature stress (ETS) with ongoing climate change. It is projected that ETS would increase notably across the world in the future. However, the spatio‐temporal change of ETS in main rice planting areas in China is still unclear; and the future yield loss caused by ETS (YLETS) has seldom been investigated quantitatively. In this study, we first investigated the spatio‐temporal change of ETS across China under 20 climate change scenarios consisting of five global climate models and four Representative Carbon Pathways (2.6, 4.5, 6.0, and 8.5). Then, using a process‐based crop model (MCWLA‐Rice), its 30 sets of model parameters and the 20 climate change scenarios, we conducted a super‐ensemble assessment to investigate the YLETS over 2020–2049, relative to the baseline period (1980–2009), across China. The results showed that, an increased heat ETS and a decreased cold ETS would be expected for most areas. As a result, a large spatial variability of yield loss would be expected in the future, including severely cold stress for region I (northeastern China, single rice) and region IV (southern China, early rice), but severely heat stress for region III (the middle and lower reaches of Yangtze River, single rice) and region IV (southern China, late rice). Comparing yield loss from both ETS, a decreased change in yield loss would be mainly expected in region I (northeastern China, single rice), while an increased change for region III (the middle and lower reaches of Yangtze River, single rice) and IV (southern China, late rice), with less change for region II (southwestern China, single rice) and IV (southern China, early rice). Finally, some adaptation measures were proposed for the ETS‐sensitive areas. Our findings are useful to develop effective policies to cope with climate risk and relieve ETS disasters.
A Retrospective Study of Cytogenetic Results From Amniotic Fluid in 5328 Fetuses With Abnormal Obstetric Sonographic Findings
Authors: Zhang Shuo , Lei Caixia , Wu Junping , Sun Haiyan , Yang Yuezhou , Zhang Yueping , Sun Xiaoxi
Published: May 2017

Objectives

The purpose of this study was to evaluate the diagnostic utility of karyotype analysis of amniotic fluid for fetuses with abnormal sonographic findings and to determine the detection rates of abnormal karyotypes.

Methods

We conducted a retrospective study of 5328 fetuses with abnormal sonographic findings in the first or second trimester enrolled from October 1998 and September 2015. Cytogenetic results from amniotic fluid were obtained in all of these pregnancies. Sonographic abnormalities were stratified according to anatomic system involvement.

Results

A total of 238 abnormal karyotypes were encountered in the 5328 fetuses (4.5%). The highest rate of chromosomal anomalies was in fetuses with structural abnormalities in multiple organ systems (25.7%), followed by an abnormal amniotic fluid volume (7.9%), structural abnormalities in a single system (7.3%), multiple nonstructural anomalies (7.2%), isolated placental abnormalities (7.1%), and isolated soft markers for aneuploidy (2.4%; P < .01). Among abnormalities in a single system, gastrointestinal and neck/body fluids had particularly high detection rates (26.1% and 26.2%, respectively). A detailed analysis suggested that the probability of an abnormal karyotype among every anatomic system was statistically significant (P < .01). This study identified several common indications with extremely high abnormal rates: duodenal atresia (53.1%), holoprosencephaly (48.8%), fetal hydrops (39.5%), cerebellar hypoplasia (32.0%), cystic hygroma (31.5%), absent/short nasal bone (11.0%), and bilateral choroid plexus cysts (8.5%).

Conclusions

Cytogenetic analysis has important clinical utility in a wide range of settings, such as prenatal diagnosis. For fetuses with indications of a highly abnormal detection rate, karyotype analysis should be suggested.
The Complexation between Amide Groups of Polyamide‐6 and Polysulfides in the Lithium–Sulfur Battery
Authors: Tang Zhen , Yang Quanling , Liu Bin , Wang Mengkui , Wang Shan , Xiong Chuanxi
Published: May 2017

Lithium–sulfur batteries have attracted considerable attention due to its high theoretical specific capacity, low cost, environmental friendliness, etc. However, the dissolution of polysulfide intermediate in the electrolyte leads to rapid capacity decay in the charge–discharge process. A sulfur‐based cathode with the specific discharge capacity of 630 mAh g−1 and ultrahigh capacity retention ratio of 0.11% per cycle after 400 cycles at 0.5 C that simply blend the sublimed sulfur and acetylene black in the mortar with the polyamide‐6 (PA6) as binder is reported. The intense complexation between the lithium polysulfide and amide groups (CONH) in PA6 can effectively inhibit the “shuttling effect” and reduce the loss of active materials during the charge–discharge process. The discovery provides a handy and practicable strategy for developing the excellent cycling stability lithium–sulfur batteries.

image
Snapshot whole‐brain T1 relaxometry using steady‐state prepared spiral multislice variable flip angle imaging
Authors: Heule Rahel , Pfeuffer Josef , Bieri Oliver
Published: May 2017

Purpose

Variable flip angle (VFA) imaging is widely used for whole‐brain T1 quantification. Because of the requirement to acquire at least two sets of MR images at different flip angles, VFA relaxometry is relatively slow. Here, whole‐brain VFA T1 mapping at 1.5 T is accelerated by using efficient spiral non‐Cartesian imaging

Methods

To quantify T1 in the human brain, radiofrequency spoiled gradient‐echo imaging is performed at two optimized flip angles using an interleaved 2D multislice sequence with high spoiling efficiency. The acquisitions are accelerated by using a spiral trajectory with 10 interleaves combined with a dedicated magnetization preparation to ensure steady‐state conditions in minimal time.

Results

The investigated MR scan protocol allowed the acquisition of whole‐brain T1 maps at a clinically relevant resolution in only 40 s (0.7 s per slice) with high reproducibility. White and gray matter T1 peaks clearly could be delineated by calculation of whole‐brain T1 histograms, and the delivered T1 values showed good agreement with the reference method in selected regions of interest.

Conclusion

Due to the use of a fast spiral k‐space trajectory, whole‐brain VFA T1 mapping could be accelerated by an order of magnitude compared to conventional Cartesian sampling. Magn Reson Med 79:856–866, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
The larmor frequency shift in magnetically heterogeneous media depends on their mesoscopic structure
Authors: Ruh Alexander , Scherer Harald , Kiselev Valerij G.
Published: May 2017

Purpose

Recent studies have addressed the determination of the NMR precession frequency in biological tissues containing magnetic susceptibility differences between cell types. The purpose of this study is to investigate the dependence of the precession frequency on medium microstructure using a simple physical model.

Theory

This dependence is governed by diffusion of NMR‐visible molecules in magnetically heterogeneous microenvironments. In the limit of fast diffusion, the precession frequency is determined by the average susceptibility‐induced magnetic field, whereas in the limit of slow diffusion it is determined by the average local phase factor of precessing spins.

Methods

The main method used is Monte Carlo simulation of isotropic suspensions of impermeable magnetized spheres. In addition, NMR spectroscopy was performed in aqueous suspensions of polystyrene microbeads.

Results

The precession frequency depends on the structural organization of magnetized objects in the medium. Monte Carlo simulations demonstrated a nonmonotonic transition between the regimes of fast and slow diffusion. NMR experiments confirmed the transition, but were unable to confirm its precise form. Results for a given pattern of structural organization obey a scaling law.

Conclusion

The NMR precession frequency exhibits a complex dependence on medium structure. Our results suggest that the commonly assumed limit of fast water diffusion holds for biological tissues with small cells. Magn Reson Med 79:1101–1110, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Prevalence of high fractional exhaled nitric oxide among US youth with asthma
Authors: Nguyen Duong T. , Kit Brian K. , Brody Debra , Akinbami Lara J.
Published: May 2017

BACKGROUND

High fractional exhaled nitric oxide (FeNO) is an indicator of poor asthma control and has been proposed as a non‐invasive assessment tool to guide asthma management.

OBJECTIVE

We aimed to describe the prevalence of and factors associated with high FeNO among US youth with asthma.

METHODS

Data from 716 children and adolescents with asthma ages 6‐19 years who participated in the 2007‐2012 National Health and Nutrition Examination Survey were analyzed. Using American Thoracic Society guidelines, high FeNO was defined as >50 ppb for ages 12‐19 years and >35 ppb for ages 6‐11 years. Multivariate logistic regression examined associations between high FeNO and age, sex, race/Hispanic origin, income status, weight status, tobacco smoke exposure, and other factors associated with asthma control (recent use of inhaled corticosteroids, recent respiratory illness, asthma‐related respiratory signs/symptoms, and spirometry).

RESULTS

About 16.5% of youth with asthma had high FeNO. The prevalence of high FeNO was higher among non‐Hispanic black (27%, P < 0.001) and Hispanic (20.2%, P = 0.002) youth than non‐Hispanic white (9.7%) youth. Differences in high FeNO prevalence by sex (girls < boys), weight status (obese < normal weight), tobacco smoke exposure (smokers < home exposure < no exposure), and FEV1/FVC (normal < abnormal) were also observed. No differences were noted between categories for the remaining covariates.

CONCLUSION

High FeNO was observed to be associated with sex, race/Hispanic origin, weight status, tobacco smoke exposure, and abnormal FEV1/FVC, but was not associated with asthma‐related respiratory symptoms. These findings may help inform future research and clinical practice guidelines on the use of high FeNO in the assessment of asthma control.
Dynamic network monitoring and control of in situ image profiles from ultraprecision machining and biomanufacturing processes
Authors: Kan Chen , Yang Hui
Published: May 2017

In modern industries, advanced imaging technology has been more and more invested to cope with the ever‐increasing complexity of systems, to improve the visibility of information and enhance operational quality and integrity. As a result, large amounts of imaging data are readily available. This presents great challenges on the state‐of‐the‐art practices in process monitoring and quality control. Conventional statistical process control (SPC) focuses on key characteristics of the product or process and is rather limited to handle complex structures of high‐dimensional imaging data. New SPC methods and tools are urgently needed to extract useful information from in situ image profiles for process monitoring and quality control. In this study, we developed a novel dynamic network scheme to represent, model, and control time‐varying image profiles. Potts model Hamiltonian approach is introduced to characterize community patterns and organizational behaviors in the dynamic network. Further, new statistics are extracted from network communities to characterize and quantify dynamic structures of image profiles. Finally, we design and develop a new control chart, namely, network‐generalized likelihood ratio chart, to detect the change point of the underlying dynamics of complex processes. The proposed methodology is implemented and evaluated for real‐world applications in ultraprecision machining and biomanufacturing processes. Experimental results show that the proposed approach effectively characterize and monitor the variations in complex structures of time‐varying image data. The new dynamic network SPC method is shown to have strong potentials for general applications in a diverse set of domains with in situ imaging data.
The changing water cycle: Burabay National Nature Park, Northern Kazakhstan
Authors: Yapiyev Vadim , Sagintayev Zhanay , Verhoef Anne , Kassymbekova Anara , Baigaliyeva Marzhan , Zhumabayev Dauren , Malgazhdar Daniyar , Abudanash Damira , Ongdas Nurlan , Jumassultanova Saltanat
Published: May 2017

Water resources in Central Asia are scarce, so complicated issues arise from this. Kazakhstan is a Central Asian landlocked country, which has mostly closed drainage basins, characterized by endorheic lakes that do not drain to the oceans. These endorheic lakes are very sensitive to climate change and anthropogenic influences. Very few studies have been conducted on the hydrological cycle of the small endorheic lakes. This work reviews the endorheic lakes within Burabay National Nature Park (BNNP), Northern Kazakhstan. BNNP is a small ecozone consisting of terminal lakes watersheds covered by mixed forests and grasslands. These endorheic lakes have been drying out during the last one hundred years or so with the water level decrease accelerated in the past few decades. According to historical observations (1935–2014), on the one hand precipitation amounts did not significantly change, while on the other hand, air temperature steadily increased. The lake level decrease is most probably caused by a water budget deficit, with evaporation exceeding the precipitation inputs in the long term. The direct anthropogenic impact (water abstraction) plays a minor role in the deterioration of water levels, with most significant impacts through localized land‐use changes such as road and building construction in the catchments. The future of the park's sensitive ecosystems in a changing climate is uncertain; therefore, BNNP requires modern ecohydrological monitoring methods and analysis tools to improve our understanding of its hydrological cycle variability, and to enable us to develop adequate adaptation and mitigation measures. WIREs Water 2017, 4:e1227. doi: 10.1002/wat2.1227

This article is categorized under:

Engineering Water > Planning Water

Water and Life > Stresses and Pressures on Ecosystems

Science of Water > Water and Environmental Change
Status and prospects of supercritical alcohol transesterification for biodiesel production
Authors: Deshpande Shriyash R. , Sunol Aydin K. , Philippidis George
Published: May 2017

The growth in the global fuel consumption is expected to continue unabated. At the same time, nations around the globe are trying to reduce greenhouse gas emissions resulting from the transportation sector. These factors have led researchers to look for alternative sources of fuels. Biodiesel is one such alternative fuel that can complement or displace petroleum diesel with a potentially lower carbon footprint fuel, depending upon the feedstock and the production process. Biodiesel refers to the monoalkyl esters derived from a wide range of raw materials, like vegetable oils, animal fats, and algae lipids. Conventionally, biodiesel is produced by transesterification with the help of an acid, base or enzyme catalyst. Certain drawbacks, like slow reaction times, soap formation and intense pre‐ and post‐processing, are associated with conventional transesterification, ultimately leading to increased capital and production costs. Supercritical transesterification is a relatively new technique promising to provide advantages, such as faster reaction times, catalyst‐free operation, and higher purity of final product, over the conventional transesterification method. The most common feedstocks are virgin and used edible oils from crops like soybean, rapeseed, and African palm. There is an increasing interest in algae to avoid the utilization of food resources for energy production. Using algae as a lipid source, a more sustainable biodiesel production process could be developed to achieve large‐scale production capabilities on a long‐term basis without adverse effects on the food chain. This paper presents a critical review of supercritical transesterification and its prospects for biodiesel production. WIREs Energy Environ 2017, 6:e252. doi: 10.1002/wene.252

This article is categorized under:

Bioenergy > Science and Materials

Bioenergy > Systems and Infrastructure

Energy and Development > Science and Materials
Gender and Student Leadership: A Critical Examination
Authors: Haber‐Curran Paige , Tillapaugh Daniel
Published: May 2017

This chapter includes an overview of existing and emerging literature on gender and student development and key opportunities for leadership educators’ practice to broaden our understanding of gender and student leadership.
Student Leadership Development for Girls and Young Women
Authors: Haber‐Curran Paige , Sulpizio Lorri
Published: May 2017

In this chapter, the authors examine the current literature and identify critical areas for future practice to support the needs of girls and young women and their leadership practices.
Synthesis, Crystal Structure of a New Structure Type, and Thermal Analysis of the Ammonium Borophosphate (NH4)2[B2P3O11(OH)]
Authors: Förg Katharina , Höppe Henning A.
Published: May 2017

(NH4)2[B2P3O11(OH)] was synthesized as a crystalline colorless powder by reaction of (NH4)2HPO4, H3BO3, and H3PO4 under hydrothermal conditions at 180 °C. According to X‐ray single‐crystal investigations (NH4)2[B2P3O11(OH)] crystallizes in a new structure type in the orthorhombic space group P212121 (no. 19) [Z = 4, a = 4.509(3), b = 14.490(11), c = 16.401(12) Å, R1 = 0.046, wR2 = 0.093, 1682 data, 200 parameters]. The crystal structure comprises infinite layers of corner‐sharing borate, phosphate and hydroxo‐phosphate tetrahedra with ammonium ions in‐between. The loop‐Branched (lB) zweier‐single layer reveals an open‐Branched (oB) vierer‐single ring as fundamental building unit (FBU), which was observed in (NH4)2MnII[B2P3O11(OH)2]Cl[1] for the first time. Besides the spectroscopic properties the thermal behavior is presented as well.
Multilevel Multivariate Meta-analysis with Application to Choice Overload
Authors: McShane Blakeley B. , Böckenholt Ulf
Published: May 2017

We introduce multilevel multivariate meta-analysis methodology designed to account for the complexity of contemporary psychological research data. Our methodology directly models the observations from a set of studies in a manner that accounts for the variation and covariation induced by the facts that observations differ in their dependent measures and moderators and are nested within, for example, papers, studies, groups of subjects, and study conditions. Our methodology is motivated by data from papers and studies of the choice overload hypothesis. It more fully accounts for the complexity of choice overload data relative to two prior meta-analyses and thus provides richer insight. In particular, it shows that choice overload varies substantially as a function of the six dependent measures and four moderators examined in the domain and that there are potentially interesting and theoretically important interactions among them. It also shows that the various dependent measures have differing levels of variation and that levels up to and including the highest (i.e., the fifth, or paper, level) are necessary to capture the variation and covariation induced by the nesting structure. Our results have substantial implications for future studies of choice overload.
Rapid Identification and Relative Quantification of the Phospholipid Composition in Commercial Lecithins by 31P NMR
Authors: Yang Ying , Hiserodt Richard , Li Jing
Published: May 2017

31P NMR analysis of samples prepared in a sodium cholate detergent system was used as a method for the identification and quantification of enzymatic hydrolysis products of lecithin. To precisely characterize all of the hydrolysis products from commercial lecithin, a series of enzymatic reactions of each phospholipid with phospholipase PLA1 were conducted and monitored by 31P NMR at different times. Twenty‐six phosphorus‐containing hydrolysis products from six classes of phospholipids (PC, PI, PS, PE, PG, PA) were found and determined by 31P NMR measurement. The impact of pH on the chemical shift values for these hydrolysis products was observed and reported. To the best of our knowledge, this is the first report of 31P‐NMR chemical shift values for entire lyso‐phospholipids hydrolyzed from 6 classes of phospholipids. Rapid and routine analysis of phospholipid composition in commercial lecithins by 31P NMR was achieved without the need of phospholipid standards.
Transcriptional and Post-Transcriptional Gene Regulation by Long Non-Coding RNA
Authors: Dykes Iain M. , Emanueli Costanza
Published: May 2017

Advances in genomics technology over recent years have led to the surprising discovery that the genome is far more pervasively transcribed than was previously appreciated. Much of the newly-discovered transcriptome appears to represent long non-coding RNA (lncRNA), a heterogeneous group of largely uncharacterised transcripts. Understanding the biological function of these molecules represents a major challenge and in this review we discuss some of the progress made to date. One major theme of lncRNA biology seems to be the existence of a network of interactions with microRNA (miRNA) pathways. lncRNA has been shown to act as both a source and an inhibitory regulator of miRNA. At the transcriptional level, a model is emerging whereby lncRNA bridges DNA and protein by binding to chromatin and serving as a scaffold for modifying protein complexes. Such a mechanism can bridge promoters to enhancers or enhancer-like non-coding genes by regulating chromatin looping, as well as conferring specificity on histone modifying complexes by directing them to specific loci.
A writer’s guide to education scholarship: Qualitative education scholarship (part 2)
Authors: Chan Teresa M. , Ting Daniel K. , Hall Andrew Koch , Murnaghan Aleisha , Thoma Brent , McEwen Jill , Yarris Lalena M.
Published: May 2017

Objective

Education scholarship can be conducted using a variety of methods, from quantitative experiments to qualitative studies. Qualitative methods are less commonly used in emergency medicine (EM) education research but are well-suited to explore complex educational problems and generate hypotheses. We aimed to review the literature to provide resources to guide educators who wish to conduct qualitative research in EM education.

Methods

We conducted a scoping review to outline: 1) a list of journals that regularly publish qualitative educational papers; 2) an aggregate set of quality markers for qualitative educational research and scholarship; and 3) a list of quality checklists for qualitative educational research and scholarship.

Results

We found nine journals that have published more than one qualitative educational research paper in EM. From the literature, we identified 39 quality markers that were grouped into 10 themes: Initial Grounding Work (preparation, background); Goals, Problem Statement, or Question; Methods (general considerations); Sampling Techniques; Data Collection Techniques; Data Interpretation and Theory Generation; Measures to Optimize Rigour and Trustworthiness; Relevance to the Field; Evidence of Reflective Practice; Dissemination and Reporting. Lastly, five quality checklists were found for guiding educators in reporting their qualitative work.

Conclusion

Many problems that EM educators face are well-suited to exploration using qualitative methods. The results of our scoping review provide publication venues, quality indicators, and checklists that may be useful to EM educators embarking on qualitative projects.
Direct numerical simulations of supersonic turbulent channel flows of dense gases
Authors: Sciacovelli L. , Cinnella P. , Gloerfelt X.
Published: May 2017

The influence of dense-gas effects on compressible wall-bounded turbulence is investigated by means of direct numerical simulations of supersonic turbulent channel flows. Results are obtained for PP11, a heavy fluorocarbon representative of dense gases, the thermophysics properties of which are described by using a fifth-order virial equation of state and advanced models for the transport properties. In the dense-gas regime, the speed of sound varies non-monotonically in small perturbations and the dependency of the transport properties on the fluid density (in addition to the temperature) is no longer negligible. A parametric study is carried out by varying the bulk Mach and Reynolds numbers, and results are compared to those obtained for a perfect gas, namely air. Dense-gas flow exhibits almost negligible friction heating effects, since the high specific heat of the fluids leads to a loose coupling between thermal and kinetic fields, even at high Mach numbers. Despite negligible temperature variations across the channel, the mean viscosity tends to decrease from the channel walls to the centreline (liquid-like behaviour), due to its complex dependency on fluid density. On the other hand, strong density fluctuations are present, but due to the non-standard sound speed variation (opposite to the mean density evolution across the channel), the amplitude is maximal close to the channel wall, i.e. in the viscous sublayer instead of the buffer layer like in perfect gases. As a consequence, these fluctuations do not alter the turbulence structure significantly, and Morkovin’s hypothesis is well respected at any Mach number considered in the study. The preceding features make high Mach wall-bounded flows of dense gases similar to incompressible flows with variable properties, despite the significant fluctuations of density and speed of sound. Indeed, the semi-local scaling of Patelet al.(Phys. Fluids, vol. 27 (9), 2015, 095101) or Trettel & Larsson (Phys. Fluids, vol. 28 (2), 2016, 026102) is shown to be well adapted to compare results from existing surveys and with the well-documented incompressible limit. Additionally, for a dense gas the isothermal channel flow is also almost adiabatic, and the Van Driest transformation also performs reasonably well. The present observations open the way to the development of suitable models for dense-gas turbulent flows.
Burns H. Weston (1933–2015)
Authors: Richardson Henry J. , Wing Adrien K.
Published: May 2017

Burns Weston, a member of the Board of Editors of thisJournalfrom 1974 to 1999, and an Honorary Editor thereafter, died unexpectedly on October 28, 2015, late in his eighty-first year, in Iowa City, Iowa. All who knew him, as friend, colleague, student, or collaborator, marveled at his seemingly boundless energy and determination, his focused devotion to whatever project involved him, his deep intellect and flowing humor, his endless imagination for creating a better world, his talent at institution building, and his ongoing curiosity propelling a dedication to achieving progress in the human condition. His professional life featured an inexhaustible determination to use international law to protect human dignity around the world. His interests, expertise, and scholarship in international claims law, human rights law, environmental law, nuclear disarmament, and global governance in particular were surpassing in their consistent excellence, continuous push against familiar doctrinal parameters, and his rich profusion of published scholarship.
So eh? is Canadian, eh?
Authors: Avis Walter S.
Published: May 2017

In a somewhat condescending review of A Dictionary of Canadianisms on Historical Principles some years ago, Mavor Moore complained about “a slighting of spoken practice and of distinctive Canadian syntax,” among his objections being the absence of an entry for eh?, for “both the English and the Americans can spot a Canadian from his ‘eh?’ at the end of a sentence: ‘It’s hot, eh?’” Admittedly, the interjection is not in the DC; moreover, there are no slips for eh? in the citation files of the Lexicographical Centre for Canadian English. This situation certainly indicates that the readers for the DC did not consider it a Canadianism: either that or they were unaware that eh? might be relevant to the collection.

The second of these possibilities may be set aside, for eh? is, in fact, entered in the Intermediate Dictionary and the Senior Dictionary, general dictionaries of English published in Canada for Canadians as part of the Dictionary of Canadian English series, to which the DC belongs. It should be added that eh? is also entered in every general dictionary of English, both British and American, on my shelves—a very considerable collection indeed, and one which includes the Oxford English Dictionary and Webster’s New International Dictionary (Third Edition).