bluuebunny/crossref_metadata_2025 huggingface dataset:
Maximum wet‐bulb globe temperature mapping in central–south Brazil: a numerical study
Authors: Bitencourt Daniel P.
Published: October 2018

Heatwaves have been getting more intense and frequent in Brazil. They affect public health, mainly outdoor workers, who are vulnerable to them; therefore, public policies focused on this population must be improved. The aim of the present study was to show the spatial behaviour of the maximum wet‐bulb globe temperature (WBGT) in central–south Brazil, at domain 34.5–14.8° S latitude and 61.7–37.3° W longitude. The air temperature under heatwave influence is often extreme in this domain and it can exceed 40°C. The WBGT is based on simulated and observed meteorological data. Numerical simulations were conducted for 9 hr (day shift) in each of the 28 days under heatwave influence. The simulated and observed WBGT values were compared to test the model skill assessment. The maximum WBGT of each grid point took into consideration all the schedules and simulation days. Based on the skill results, the simulated WBGT performance was good, mainly in areas recording a higher WBGT; outdoor workers subjected to moderate and heavy workload must be subjected to control measures or stop working in most central–south domains during periods under heatwave influence. In the most critical cases, outdoor workers should be prevented from heavy workload throughout the entire work shift because they are exposed to almost 8 hr of WBGT higher than 30°C.
A novel unidirectional multi‐dipole broadband antenna element
Authors: Chen Yanzheng , Lin Wenbin , Ma Cunliang , Liao Cheng
Published: October 2018

A novel wideband unidirectional multi‐dipole antenna is proposed, which has an enhanced impedance bandwidth of about 68.1% for VSWR < 1.5 and a gain > 8 dBi, covering the frequency region from 1.54 to 3.13 GHz. A stable radiation pattern is obtained and the 3 dB beamwidth is 62 ± 4° at E‐plane and 63 ± 4° at H‐plane over the bandwidth. This model has been manufactured, and the experimental results are in good accordance with the simulated ones.
Investigation of the influence of macromolecules and spline baseline in the fitting model of human brain spectra at 9.4T
Authors: Giapitzakis Ioannis‐Angelos , Borbath Tamas , Murali‐Manohar Saipavitra , Avdievich Nikolai , Henning Anke
Published: October 2018

Purpose

In this study, the influence of experimentally measured macromolecules and spline baseline on the quantification results of proton MRS data was investigated.

Methods

Proton MRS spectra from the left parietal lobe and the occipital lobe were acquired at 9.4T in the human brain using metabolite‐cycled semi‐LASER. Then, the left parietal lobe data, along with the occipital lobe, spectra were quantified and the influence of the inclusion of experimentally measured macromolecular basis sets in the fitting model was evaluated. Furthermore, the effect of the stiffness of the fitted spline baselines on the resulting metabolite concentrations was evaluated.

Results

In general, concentrations were higher for metabolites in occipital lobe than the left parietal lobe. The inclusion of an experimentally acquired measured macromolecular basis set from another brain region neither affected the quantification results nor the resulting spline baselines significantly. A highly flexible spline baseline led to overestimation or underestimation of metabolite concentrations. Differences of above 15% in the quantification of metabolite levels for both lobes were observed for several metabolites using LCModel default settings for spline baselines and macromolecules in comparison to stiffer spline baselines.

Conclusion

Fitting with the default LCModel macromolecular basis set and spline baseline model had significant influence in the resulting spline baselines, leading to large deviations both in the concentrations and fitted macromolecular components. The number of knots in the spline may create overflexible baselines, which can potentially lead to quantification errors. Interestingly, the interchange of macromolecular basis set between occipital lobe and left parietal lobe spectra had less influence on the quantification results compared to the default LCModel settings.
Trajectory optimized NUFFT: Faster non‐Cartesian MRI reconstruction through prior knowledge and parallel architectures
Authors: Smith David S. , Sengupta Saikat , Smith Seth A. , Brian Welch E.
Published: October 2018

Purpose

The non‐uniform fast Fourier transform (NUFFT) involves interpolation of non‐uniformly sampled Fourier data onto a Cartesian grid, an interpolation that is slowed by complex, non‐local data access patterns. A faster NUFFT would increase the clinical relevance of the plethora of advanced non‐Cartesian acquisition methods.

Methods

Here we customize the NUFFT procedure for a radial trajectory and GPU architecture to eliminate the bottlenecks encountered when allowing for arbitrary trajectories and hardware. We call the result TRON, for TRajectory Optimized NUFFT. We benchmark the speed and accuracy TRON on a Shepp‐Logan phantom and on whole‐body continuous golden‐angle radial MRI.

Results

TRON was 6–30× faster than the closest competitor, depending on test data set, and was the most accurate code tested.

Conclusions

Specialization of the NUFFT algorithm for a particular trajectory yielded significant speed gains. TRON can be easily extended to other trajectories, such as spiral and PROPELLER. TRON can be downloaded at http://github.com/davidssmith/TRON.
Metabolic profiling of listeria rhombencephalitis in small ruminants by 1H high‐resolution magic angle spinning NMR spectroscopy
Authors: Precht Christina , Diserens Gaëlle , Vermathen Martina , Oevermann Anna , Lauper Josiane , Vermathen Peter
Published: October 2018

Listeria rhombencephalitis is caused by infection with Listeria monocytogenes and is associated with a high mortality rate in humans and ruminants. Little is known about the metabolic changes associated with neurolisteriosis in particular and infectious central nervous system (CNS) diseases in general. The purpose of our study was to investigate the metabolic changes associated with listeria rhombencephalitis in small ruminants (goats and sheep) as a model for inflammatory CNS disease by 1H high‐resolution magic angle spinning nuclear magnetic resonance (1H HR‐MAS NMR) spectroscopy of brain biopsies obtained from the brainstem and thalamus. Statistical analysis revealed distinct differences in the metabolic profile of brainstem biopsies, the primary location of listeria rhombencephalitis with moderate or severe inflammatory changes. N‐Acetylaspartate (NAA), N‐acetylaspartylglutamate, choline, myo‐inositol and scyllo‐inositol were decreased, and glycine, phosphocholine, taurine and lactate were increased, in the diseased group (n = 13) in comparison with the control group (n = 12). In the thalamus, which showed no or only mild inflammatory changes in the majority of animals, no statistically significant metabolic changes were observed. However, trends for metabolic alterations were partly the same as those found in the brainstem, including NAA, choline and lactate. This may be an indicator of metabolic changes occurring in the early stages of the disease. Therefore, further research with a larger number of animals is needed to evaluate the presence of subtle metabolic changes associated with mild inflammatory changes in the thalamus. In conclusion, 1H HR‐MAS NMR investigation of listeria rhombencephalitis identified brain metabolite changes, offering new insights into the disease pathophysiology.
Cross‐linked waterborne alkyd hybrid resin coatings modified by fluorinated acrylate‐siloxane with high waterproof and anticorrosive performance
Authors: Zhong Shenjie , Li Jiawei , Yi Lingmin , Cai Ying , Zhou Wenlong
Published: October 2018

Waterborne alkyd resin coatings are ideal for use as corrosion protection coatings because of its high cost‐effective and environmental advantages. However, their uses are restricted to general applications due to their poor acid, water, and alkali resistance. In this work, waterborne alkyd hybrid resins modified with fluorinated acrylate‐siloxane were synthesized via a surfactant‐free miniemulsion polymerization process using maleic anhydride and silicon modified alkyd resin, dodecafluoroheptyl methacrylate, methyl methacrylate, and butyl acrylate as monomers. And then, crosslinking alkyd resin films were prepared at room temperature using trimethylolpropane‐tris‐(β‐N‐azir‐idinyl) propionate (XR‐100) as the crosslinking agent. The acquired films had lower water absorption and higher water contact angles and had better mechanical/thermal properties, as well as good waterproof property. Most importantly, the electrochemical corrosion studies revealed that the cross‐linked coating exhibited superior corrosion resistance performance with an inhibition efficiency of 99.95% and a corrosion rate of 6.95 × 10−3 mm per year.
Tensile, electromagnetic, and far‐infrared properties of stainless steel/far‐infrared polyester composite materials
Authors: Lin Ting An , Shiu Bing‐Chiuan , Lin Jia‐Horng , Lou Ching‐Wen
Published: October 2018

In this study, a continuous‐forming wrapping process simultaneously feeds far‐infrared ray polyester (FIR‐PET) filaments and stainless steel (SS) wire to prepare functional SS/FIR‐PET composite wrapped yarns. The wrapped yarns are made into functional SS/FIR‐PET composite woven fabrics. The cover factor, tensile properties, electromagnetic shielding effectiveness (EMSE), FIR emissivity, and air permeability of the wrapped yarns and woven fabrics are evaluated, examining the influences of the combinations of diameter of SS wires (0.05 and 0.08 mm are referred as 005SS and 008SS) and wrapped count (7, 10, and 13, turns/cm). For SS/FIR‐PET composite wrapped yarns, 005SS‐7 (0.05‐mm SS with wrapped counts 7 turns/ cm) and 008SS‐7 (SS/ FIR‐PET composite wrapped yarns with 0.08‐mm SS and wrapped counts 7 turns/ cm) have the optimal tensile strength and tenacity, while 008SS‐13 has the optimal elongation and work of rupture. For SS/ FIR‐PET composite woven fabrics, 008SS‐W (W regarded as woven fabric) has the optimal tensile properties; 008SS‐W‐10 has the maximum stress at break of 27.01 MPa along the weft direction; and 008SS‐W‐13 has the maximum elongation at break of 29.83% along the weft direction. The EMSE test results confirm that changing the number of lamination layers and changing the lamination angles have a positive influence on the EMSE of the woven fabrics. The EMSE of 008SS‐W reaches −40 dB when the number of lamination layers is 3 and the lamination angle is 90°. Moreover, the EMSE of 008SS‐W reaches 0.85 when the number of lamination layers is 3. It is expected to apply functional SS/FIR‐PET woven fabric in practical domains, which that can be regarded as the middle layer of laminated composite fabric or health‐care textile. The functional SS/FIR‐PET woven fabric can give traditional laminated composite fabric with the electromagnetic‐shielding ability and FIR emissivity, and thus highly enhance the additional value of traditional composite fabrics. POLYM. COMPOS., 40:2219–2230, 2019. © 2018 Society of Plastics Engineers
Extending compound identification for molecular network using the LipidXplorer database independent method: A proof of concept using glycoalkaloids from Solanum pseudoquina A. St.‐Hil.
Authors: Soares Vitor , Taujale Rahil , Garrett Rafael , da Silva Antonio Jorge R. , Borges Ricardo M.
Published: October 2018

Introduction

Molecular networks are now established as the method of choice for tandem mass spectrometry dereplication and similarity‐based structure elucidation. Node identification can be used to start the propagation of the structure elucidation of unknown compounds progressively.

Objective

To demonstrate the capabilities of using the LipidXplorer data results along with molecular networking to identify nodes and aid sequential structure elucidation of unknown compounds.

Material and Methods

Molecular fragmentation query language (MFQL) files were written to identify glycoalkaloids based on known structures described for Solanum species. A dataset generated from liquid chromatography‐high resolution mass spectrometry (LC‐HRMS) analysis of Solanum pseudoquina sample were submitted to dereplication on both LipidXplorer software and Global Natural Products Social Molecular Network (GNPS) online system. The resulting attribute table from GNPS calculations was merged with the LipidXplorer results and this merged file was used for network visualisation in Cytoscape. Nodes in the molecular network were labelled using the LipidXplorer identifiers, thus assisting the structure elucidation of unidentified compounds.

Results

The combination of the LipidXplorer glycoalkaloids list and GNPS analysis was used in Cytoscape to label nodes in the molecular network. The analysis of the network using these labelled starting points triggered the structure elucidation of closely related nodes leading to the identification of 30 compounds using the LipidXplorer output and four purified and structure elucidated compounds, including a new glycoalkaloids identified as 3‐O‐(β‐d‐xylopyranosyl)‐(20R,25S)‐22,26‐epimino‐16‐acetyl‐cholesta‐5,22(N)‐diene.

Conclusion

A significant compound identification completely based on molecular formula and fragmentation queries was achieved. This new and effective approach could help researches to expand the identification rate of compounds in dereplication studies using molecular networks.
Hair cortisol levels and symptoms of anxiety and depression in Chinese adolescents: Comparison between incarcerated and community populations
Authors: Xu Youyun , Li Jifeng , Xie Qiaozhen , Deng Huihua
Published: October 2018

Hair cortisol has been proposed as a temporally integrated measure of systemic cortisol suitable for studies of chronic stress. We compared hair cortisol and depressive and anxiety symptoms between two groups of healthy male adolescents differing in exposure to chronic stress, one attending regular high school (n = 33) and the other incarcerated for 11–867 days in juvenile detention (n = 29), and examined the association of hair cortisol and depressive and anxiety symptoms among all adolescents. Hair cortisol was determined by liquid chromatography tandem mass spectrometry, and depressive and anxiety symptoms were measured by the Self‐Rating Depression and Anxiety Scales. Hair samples (1‐cm segments closest to the scalp at the posterior vertex) were collected 2 weeks after psychometric testing. Results revealed that incarcerated adolescents showed significantly more anxiety and depression symptoms, and higher hair cortisol levels than high school adolescents (ps < .05). The regression results revealed that hair cortisol levels could negatively predict depression symptoms (p < .05) but could not predict anxiety symptoms (p > .05) among all adolescents from the two groups. In summary, incarcerated adolescents experienced significantly higher chronic stress than high school adolescents. Hair cortisol showed a negative association with depression symptoms and no association with anxiety symptoms among adolescents with different exposures to chronic stress.
Short‐term relocation versus long‐term migration: Implications for economic growth and human capital change
Authors: Newbold K. Bruce
Published: October 2018

Driven by the growth of Canada's resource sector, interprovincial employees (IPEs), or individuals who work in one province and reside in another, have emerged as the main source for interprovincial worker mobility within Canada, with their numbers far exceeding the number of interprovincial migrants (individuals who permanently relocate from one province to another) on a yearly basis. As such, IPEs represent a significant number of workers and play an increasingly important role in the Canadian labour market, enabling individuals to respond to skill shortages and job opportunities over both the short and long term. This paper contrasts these two groups using a number of measures commonly used to characterise interprovincial migration. Results reveal that although the two groups are broadly similar, there are also subtle differences between the two groups, including differences in the age migration schedule and other sociodemographic characteristics of IPEs.
Temperature and Electric Field Dependence of Spin Relaxation in Graphene on SrTiO3
Authors: Chen Si , Ruiter Roald , Mathkar Vikramaditya , van Wees Bart J. , Banerjee Tamalika
Published: October 2018

The theoretically predicted intrinsic spin relaxation time of up to in graphene along with extremely high mobilities makes it a promising material in spintronics. Numerous experimental studies, however, find the spin lifetime in graphene to be several orders of magnitude below that theoretically predicted. Additionally, analyses of the spin relaxation mechanisms in graphene using conventional processes such as Elliot–Yaffet and D'yakonov–Perel' show a coexistence of both, with no clear dominance. Central to these experimental discrepancies is the role of the local environment including that of the underlying substrate. In this work, we use the electronically rich platform of SrTiO3 with broken inversion symmetry and study spin transport in graphene in the presence of surface electric fields. We find spin relaxation time and length as large as 0.96 ± 0.03 ns and 4.1 ± 0.1 μm, respectively at 290 K in graphene, using non‐local spin valve studies and find a non monotonous dependence with temperature, unlike that observed in other substrates. Analysis of the temperature dependence indicates the role of surface electric dipoles and electric field driven electronic and structural phase transitions unique to SrTiO3 for spin transport and spin relaxation in graphene.
A Bayesian approach to sequential monitoring of nonlinear profiles using wavelets
Authors: Varbanov Roumen , Chicken Eric , Linero Antonio , Yang Yun
Published: October 2018

We consider change‐point detection and estimation in sequences of functional observations. This setting often arises when the quality of a process is characterized by such observations, called profiles, and monitoring profiles for changes in structure can be used to ensure the stability of the process over time. While interest in phase II profile monitoring has grown, few methods approach the problem from a Bayesian perspective. We propose a wavelet‐based Bayesian methodology that bases inference on the posterior distribution of the change point without placing restrictive assumptions on the form of profiles. By obtaining an analytic form of this posterior distribution, we allow the proposed method to run online without using Markov chain Monte Carlo (MCMC) approximation. Wavelets, an effective tool for estimating nonlinear signals from noise‐contaminated observations, enable us to flexibly distinguish between sustained changes in profiles and the inherent variability of the process. We analyze observed profiles in the wavelet domain and consider two possible prior distributions for coefficients corresponding to the unknown change in the sequence. These priors, previously applied in the nonparametric regression setting, yield tuning‐free choices of hyperparameters. We present additional considerations for controlling computational complexity over time and their effects on performance. The proposed method significantly outperforms a relevant frequentist competitor on simulated data.
The influence of hydrolysis and derivatization on the determination of amino acid content and isotopic ratios in dual‐labeled (13C, 15N) white clover
Authors: Enggrob Kirsten Lønne , Larsen Thomas , Larsen Mogens , Elsgaard Lars , Rasmussen Jim
Published: October 2018

Rationale

The cycling of peptide‐ and protein‐bound amino acids (AAs) is important for studying the rate‐limiting steps in soil nitrogen (N) turnover. A strong tool is stable C and N isotopes used in combination with compound‐specific isotope analysis (CSIA), where a prerequisite for analysis is appropriate methods for peptide and protein hydrolysis and appropriate methods for derivatization of AAs for analysis by gas chromatography (GC).

Methods

We examined the efficiency of a standard acidic hydrolysis (6 M HCl, 20 h at 110°C) and a fast acidic hydrolysis (6 M HCl, 70 min at 150°C) on the recovery of AAs from a protein standard (bovine serum albumin). The best methods were used on dual‐labeled (13C and 15N) clover shoot and root juice, divided into four molecular weight (Mw) size fractions. We used NAIP (N‐acetyl isopropyl esterification) derivatization for GC/combustion‐isotope ratio mass spectrometry (C‐IRMS) analysis of AA standards.

Results

The NAIP derivatization gave very low limits of detection (LODs) (< 2 pmol) and limits of quantification (LOQs) ranging from 0.55 to 4.89 pmol. Comparing the concentrations of individual AAs in hydrolyzed versus unhydrolyzed clover juice samples of the low Mw size fraction (<1 kDa) showed a significant decline in concentration (p <0.03) for seven AAs after hydrolysis. Despite the decline in AA concentration, we found a linear connection between the obtained atomic fraction (13C/total carbon and 15N/total nitrogen) for individual AAs of hydrolyzed versus unhydrolyzed samples.

Conclusions

The methodology distinguished differences in atomic fractions across AAs, in individual AAs in Mw size fractions, and between shoot and root samples of experimentally labeled white clover. Specifically, the method separated L‐glutamate (Glu) and glutamine (Gln). Thus, for a broader use in plant and soil ecology, we present an optimized methodology for GC/C‐IRMS analysis of AAs from organic nitrogen samples enriched with 13C and 15N – AA stable isotope probing (SIP).
Discrete‐time higher‐order sliding mode control of systems with unmatched uncertainty
Authors: Sharma Nalin Kumar , Janardhanan Shivaramakrishnan
Published: October 2018

The research on discrete‐time higher‐order sliding mode has received a considerable attention recently. Systems with unmatched uncertainties are common in practice; however, the existing discrete‐time higher‐order sliding mode control algorithms are designed considering only matched uncertainty. This paper proposes a technique to design discrete‐time higher‐order sliding mode control for an uncertain LTI system in the presence of unmatched uncertainty. The proposed technique is numerically simulated and experimentally validated on an electromechanical rectilinear plant. Various experiments are conducted considering the several operational conditions of electromechanical systems in industries to verify the performance of the proposed controller.
Adaptive asymptotic stabilization of a class of unknown nonlinear systems with specified convergence rate
Authors: Zhang Jin‐Xi , Yang Guang‐Hong
Published: October 2018

This paper focuses on the asymptotic stabilization problem for a class of multivariable nonlinear systems with relative degree one, practical examples of which incorporate the liquid level control of water tanks, and the speed control of interconnected carts. The presence of the unknown (other than uncertain) additive and multiplicative nonlinearities renders asymptotic stability difficult to be achieved by the existing robust control methods. To conquer this obstacle, a novel adaptive control strategy is proposed. In the control design, the state constraint technique is newly introduced to the adaptive design to generate a proper control gain to compensate for unknown nonlinearities, instead of the use of extra approximating structures. By this means, both the prescribed transient performance regarding the convergence rate and the expected asymptotic stability are preserved. Finally, simulation results are given to illustrate the established theoretical findings.
Fast vision‐based autonomous detection of moving cooperative target for unmanned aerial vehicle landing
Authors: Li Zhaoxi , Meng Cai , Zhou Fugen , Ding Xilun , Wang Xueqiang , Zhang Huan , Guo Pin , Meng Xin
Published: October 2018

We propose a fast and effective method, fast target detection (FTD), to detect the moving cooperative target for the unmanned aerial vehicle landing, and the target is composed of double circles and a cross. The purpose of our strategy is to land on the target. The FTD method needs to detect the target at the high and low heights. At the high height, the target appears completely and stably in the camera field. The FTD method can detect the circle and cross to rapidly reach the target center, named cross and circle–FTD (). To detect the cross, we propose a slope distance equation to obtain the distance between two slopes. The proposed slopes cluster method, based on the distance equation and
K‐means, is used to determine the cross center. At the low height, the target appears incompletely and unstably. Therefore, FTD methods detect only the cross, named cross–FTD (). We extract the cross features (
CFs) based on line segments. Then, four
CFs are combined based on graph theory. Experiments on our four datasets show that FTD has rapid speed and good performance. (Our method is implemented in C++ and is available at https://github.com/Li-Zhaoxi/UAV-Vision-Servo.) On the Mohamed Bin Zayed International Robotics Challenge datasets made we constructed, detects the target from a image approximately per pipeline with
F‐measure and tracks target approximately per pipeline with
F‐measure. detects centers from a image at approximately per image with
F‐measure.
Population‐calibrated multiple imputation for a binary/categorical covariate in categorical regression models
Authors: Pham Tra My , Carpenter James R , Morris Tim P , Wood Angela M , Petersen Irene
Published: October 2018

Multiple imputation (MI) has become popular for analyses with missing data in medical research. The standard implementation of MI is based on the assumption of data being missing at random (MAR). However, for missing data generated by missing not at random mechanisms, MI performed assuming MAR might not be satisfactory. For an incomplete variable in a given data set, its corresponding population marginal distribution might also be available in an external data source. We show how this information can be readily utilised in the imputation model to calibrate inference to the population by incorporating an appropriately calculated offset termed the “calibrated‐δ adjustment.” We describe the derivation of this offset from the population distribution of the incomplete variable and show how, in applications, it can be used to closely (and often exactly) match the post‐imputation distribution to the population level. Through analytic and simulation studies, we show that our proposed calibrated‐δ adjustment MI method can give the same inference as standard MI when data are MAR, and can produce more accurate inference under two general missing not at random missingness mechanisms. The method is used to impute missing ethnicity data in a type 2 diabetes prevalence case study using UK primary care electronic health records, where it results in scientifically relevant changes in inference for non‐White ethnic groups compared with standard MI. Calibrated‐δ adjustment MI represents a pragmatic approach for utilising available population‐level information in a sensitivity analysis to explore potential departures from the MAR assumption.
Atomic Layer Deposition of Metal Oxide on Nanocellulose for Enabling Microscopic Characterization of Polymer Nanocomposites
Authors: Septevani Athanasia A. , Evans David A. C. , Hosseinmardi Alireza , Martin Darren J. , Simonsen John , Conley John F. , Annamalai Pratheep K.
Published: October 2018

Analysis of cellulose nanocrystals (CNCs) at low volume fractions in polymer nanocomposites through conventional electron microscopy still remains a challenge due to insufficient contrast between CNCs and organic polymer matrices. Herein, a methodology for enhancing the contrast of CNC, through atomic layer deposition (ALD) of alumina (Al2O3) on CNCs is demonstrated. The metal oxide coated CNC allows clear visualization by transmission electron microscopy, when they are dispersed in water and polyol. A coating of about 6 ± 1 nm thick alumina layer on the CNC is achieved after 50 ALD cycles. This also enables the characterization of CNC dispersion/orientation (at 0.2 wt% loading) in an amorphous cellular system rigid polyurethane foam (RPUF), using backscattered electron microscopy with energy‐dispersive X‐ray spectroscopy. Microscopic analysis of the RPUF with alumina‐coated CNC confirms that the predominant alignment of CNC occurs in a direction parallel to the foam rise.
N2Reduction on Fe‐Based Complexes with Different Supporting Main‐Group Elements: Critical Roles of Anchor and Peripheral Ligands
Authors: Jiang Ya‐Fei , Ma Xue‐Lu , Lu Jun‐Bo , Wang Jia‐Qi , Xiao Hai , Li Jun
Published: October 2018

Due to the enigmatic existence of the carbon atom in the MoFeS cluster of iron‐molybdenum cofactor (FeMoco), the design of biomimetic model catalysts featuring a dative bond between a transition metal and a main group atom is an important topic for efficient reduction of N2to NH3at ambient conditions. Different anchor atoms (X) for the trigonal bipyramidal (XPiPr3)Fe (X = B, C, N) catalyst scaffold are investigated by theory. The calculations show that from Lewis acidic B anchor to Lewis basic N or P anchor, the molecular orbital energy levels consisting mainly of Fe 3d orbitals are pushed higher, thus causing stronger backdonation bonding with theπ*orbitals of N2, which promotes activation of N2but impedes reduction of N2. The redox‐flexible bonding can act as an electron reservoir and buffer the oxidation state variation of Fe. However, when the FeX bond is less flexible, the peripheral ligands can serve as an extra electron reservoir in the model with Lewis basic anchor. Thus, engineering the peripheral ligand with proper electron‐withdrawing substituent groups can promote reduction of N2. The ability to balance well the electron‐donating ability of anchor and electrophilicity of the peripheral ligand is a promising direction toward novel efficient catalysts for N2fixation.
Synergistic Coupling of Ether Electrolyte and 3D Electrode Enables Titanates with Extraordinary Coulombic Efficiency and Rate Performance for Sodium‐Ion Capacitors
Authors: Gui Qiuyue , Ba Deliang , Zhao Zhenshuai , Mao Yanfang , Zhu Weihua , Lei Tianyu , Tan Jianfeng , Deng Bohua , Xiao Liang , Li Yuanyuan , Liu Jinping
Published: October 2018

Sodium‐ion capacitors (SICs) have attracted increasing attention for sustainable energy utilization owing to their low cost and similar intercalation electrochemistry with lithium‐ion capacitors. However, the practical application of SICs is seriously hindered by the low initial coulombic efficiency (ICE) and limited redox kinetics at the battery electrode side. Herein, taking a layered sodium titanate battery anode as an example, this study reports on the synergistic combination of ether electrolyte and binder‐free array architecture to simultaneously achieve superior ICE and ultrafast Na+ intercalation. The resulting Na2Ti2O5 nanosheet array anode delivers extraordinary ICE (91%), high cycle CE (≈100%), and outstanding rate performance (66% capacity retention at 120 C). The key to the superior performance lies in the synergistic promotion between electrolyte and 3D electrode architecture, which ensures a very thin and stable solid‐electrolyte interphase, largely reduced resistances, and fully accessible interlayers for Na+. Moreover, a SIC device is assembled with an Na2Ti2O5 array anode and a commercial activated carbon cathode, exhibiting high ICEs (80–90%) at various current densities, high energy densities (54.5 Wh kg−1; 17.2 mWh cm−3), and ultralong cycling stability (>10 000 cycles). This work presents an advanced concept for designing high‐CE and high‐rate battery electrodes for a variety of sodium ion energy storage systems.
Household Informedness and Long‐Run Inflation Expectations: Experimental Evidence
Authors: Binder Carola , Rodrigue Alex
Published: October 2018

This article uses an experiment embedded in a survey to analyze the response of consumers' long‐run inflation expectations to information about the Federal Reserve's inflation target and past inflation. On average, respondents revise forecasts toward the 2% target with either information treatment. Forecast uncertainty and heterogeneity decline with the treatments, but remain substantial. Since the information in the treatments is publicly available, these findings are consistent with models of imperfect information in which agents do not fully and continually update their information sets or incorporate all available information into their expectations. Response to treatments varies with prior informedness and with demographic characteristics.
Does exercise during pregnancy impact on maternal weight gain and fetal cardiac function? A randomized controlled trial
Authors: Brik M. , Fernández‐Buhigas I. , Martin‐Arias A. , Vargas‐Terrones M. , Barakat R. , Santacruz B.
Published: October 2018

Objective

To evaluate the association between physical exercise during pregnancy and maternal gestational weight gain and fetal cardiac function.

Methods

This was a randomized controlled trial of women with a singleton pregnancy managed from the first trimester at the Hospital de Torrejón, Madrid, between November 2014 and June 2015. Women were randomized to either follow a supervised physical conditioning program, consisting of a 60‐min session 3 days per week for the duration of pregnancy, or not attend any exercise program (controls). The primary outcome was maternal weight gain during pregnancy. Secondary outcomes included fetal cardiac function parameters evaluated at 20, 28 and 36 weeks' gestation, Cesarean section, preterm delivery, induction of labor and birth weight. A sample size of 45 in each group was planned to detect differences in maternal weight gain of at least 1 kg, with a power of > 80% and α of 0.05.

Results

During the study period, 120 women were randomized into the exercise (n = 75) and control (n = 45) groups. Following exclusions, the final cohort consisted of 42 women in the exercise group and 43 in the control group. Baseline characteristics (maternal age, prepregnancy body mass index, parity, conception by in‐vitro fertilization, Caucasian ethnicity, physical exercise prior to pregnancy and smoker) were similar between the two groups. No differences were found between the groups in maternal weight at 20, 28, 36 and 38 weeks' gestation or in weight gain at 38 weeks. However, the proportion of women with weight loss ≥ 9 kg at 6 weeks postpartum was higher in the exercise compared with the control group (68.2% vs 42.8%; relative risk 1.593; P = 0.02). The ductus arteriosus pulsatility index (DA‐PI) at 20 weeks (2.43 ± 0.40 vs 2.26 ± 0.33, P < 0.05) and the ejection fraction (EF) at 36 weeks (0.85 ± 0.13 vs 0.81 ± 0.11, P < 0.05) were higher in the exercise compared with the control group. All other evaluated fetal cardiac function parameters were similar between the two groups.

Conclusions

Performing exercise during pregnancy is not associated with a reduction in maternal weight gain but increases weight loss at 6 weeks postpartum. Physical exercise during pregnancy is associated with increased fetal DA‐PI at 20 weeks and EF at 36 weeks, which could reflect adaptive mechanisms. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
Mathematical modeling of circadian rhythms
Authors: Asgari‐Targhi Ameneh , Klerman Elizabeth B.
Published: October 2018

Circadian rhythms are endogenous ~24‐hr oscillations usually entrained to daily environmental cycles of light/dark. Many biological processes and physiological functions including mammalian body temperature, the cell cycle, sleep/wake cycles, neurobehavioral performance, and a wide range of diseases including metabolic, cardiovascular, and psychiatric disorders are impacted by these rhythms. Circadian clocks are present within individual cells and at tissue and organismal levels as emergent properties from the interaction of cellular oscillators. Mathematical models of circadian rhythms have been proposed to provide a better understanding of and to predict aspects of this complex physiological system. These models can be used to: (a) manipulate the system in silico with specificity that cannot be easily achieved using in vivo and in vitro experimental methods and at lower cost, (b) resolve apparently contradictory empirical results, (c) generate hypotheses, (d) design new experiments, and (e) to design interventions for altering circadian rhythms. Mathematical models differ in structure, the underlying assumptions, the number of parameters and variables, and constraints on variables. Models representing circadian rhythms at different physiologic scales and in different species are reviewed to promote understanding of these models and facilitate their use.

This article is categorized under:

Physiology > Mammalian Physiology in Health and Disease

Models of Systems Properties and Processes > Organ, Tissue, and Physiological Models
Activation of the Highly‐Selective Pd11Bi2Se2 during the Semi‐Hydrogenation of Acetylene
Authors: Aviziotis Ioannis G. , Götze André , Göhler Fabian , Kohlmann Holger , Armbrüster Marc
Published: October 2018

Pd11Bi2Se2 was prepared as single‐phase material and used in an unsupported state as catalyst in the semi‐hydrogenation of acetylene in ethylene excess. After an initial inactive time‐period, Pd11Bi2Se2 activated and showed high acetylene conversion and selectivity towards ethylene at 473 K. In addition, after the initial inactive state, the compound revealed high stability during 100 h time on stream. At 80 % conversion the selectivity to ethylene is higher than 90 %. Post‐catalysis investigations by powder X‐ray diffraction (p‐XRD) and X‐ray photoelectron spectroscopy (XPS) exclude the formation of intermetallic hydrides, decomposition, and the presence of elemental palladium. Furthermore, comparison of XPS before and after catalysis revealed the reason of the inactive state of the intermetallic compound during the first hours of catalysis. An initial surface layer of bismuth oxide is reduced and re‐incorporated into the intermetallic compound. This material change is responsible for the initially observed activation of Pd11Bi2Se2 during the semi‐hydrogenation of acetylene.
The significance of beam steering on laser-induced incandescence measurements in laminar counterflow flames
Authors: Kruse S. , Medwell P. R. , Beeckmann J. , Pitsch H.
Published: October 2018

Beam steering is often encountered in laser diagnostic measurements, especially in flame environments, due to changes in refractive index caused by thermal and species gradients. It can negatively affect the accuracy of the results. In this work, the effects of beam steering on laser-induced incandescence (LII) measurements of pre-vaporized-liquid counterflow flames are assessed. The focus on counterflow flames is to facilitate future detailed experimental campaigns on one-dimensional nonpremixed sooty flames. It is found that the temperature and species gradients in the counterflow configuration have a much more significant impact on the beam profile than in laminar flat flames, especially for heavier fuels. As a result of the changes in the beam profile, for the same applied laser energy, the local fluence shifts markedly with fuel type, therefore, having a direct impact on the LII measurements. A procedure is developed for ensuring accurate measurements and it is shown that, for a specific fuel, it is possible to tailor the laser energy, such that the collected LII signal in the counterflow flames is nearly independent of beam-steering effects.
X-chromosomale Intelligenzminderung
Authors: Tzschach Andreas
Published: October 2018

X-chromosomale Intelligenzminderung („X-linked intellectual disability“, XLID) ist eine heterogene Krankheitsgruppe; inzwischen sind mehr als 100 XLID-Gene identifiziert worden. Das Fragile-X-Syndrom mit CGG-Repeatexpansion in der 5’-UTR des FMR1-Gens ist die häufigste monogene Ursache für Intelligenzminderung. Weitere X‑chromosomale Gene mit vergleichsweise hohen Mutationsprävalenzen sind ATRX, RPS6KA3, GPC3, SLC16A2, SLC6A8 und ARX. Die Ursachen für XLID verteilen sich zu ca. 90 % auf molekulargenetisch nachweisbare Mutationen und zu ca. 10 % auf chromosomale Kopienzahlvarianten („copy-number variants“, CNVs). Häufige CNVs sind Duplikationen in Xq28 unter Einschluss von MECP2 sowie das Xp11.22-Duplikations-Syndrom mit Überexpression von HUWE1. Mit den aktuellen Untersuchungsmethoden kann bei ca. 10 % der männlichen Patienten mit Intelligenzminderung eine X‑chromosomale Ursache nachgewiesen werden. Neue Erkenntnisse zu XLID sind für die nächsten Jahre am ehesten in den nicht kodierenden Regionen zu erwarten, wo wahrscheinlich ein weiterer Teil der Ursachen für das bislang nicht vollständig erklärte Überwiegen männlicher Patienten zu suchen ist.
Au maskless patterning for vacuum packaging using the electrochemical method
Authors: Xie Bo , Chen Deyong , Wang Junbo , Chen Jian , Hong Wen
Published: October 2018

The interconnection of wires is an important issue in vacuum-packaged microelectromechanical systems devices because of the difficulties of hermetical sealing and electrical insulation. This paper presents an approach of Au film selective patterning on highly uneven surfaces for wire interconnections of devices in which silicon-on-insulator (SOI) wafers are anodically bonded to glass. The Au film on the handle layer, functioned as an anode, was selectively removed with electrochemical dissolution in a chloride solution. The choice of etchant solution and etching conditions were optimized to improve the process efficiency, resulting in a high yield of gold portions within the via holes for wire interconnection. The proposed wire interconnection technology was employed to fabricate a vacuum-packaged resonant pressure sensor as a proof-of-concept demonstration. Reliable wire bonding and vacuum package were achieved as well as a Q factor that does not decrease over a year. As a platform technology, this method provides a new approach of wire interconnection for vacuum-packaged devices based on SOI–glass anodic bonding.
Kinematic error modeling and error compensation of desktop 3D printer
Authors: Keaveney Shane , Connolly Pat , O’Cearbhaill Eoin D.
Published: October 2018

Desktop 3D printers have revolutionized how designers and makers prototype and manufacture certain products. Highly popular fuse deposition modeling (FDM) desktop printers have enabled a shift to low-cost consumer goods markets, through reduced capital equipment investment and consumable material costs. However, with this drive to reduce costs, the computer numerical control (CNC) systems implemented in FDM printers are often compromised by poor accuracy and contouring errors. This condition is most critical as users begin to use 3D-printed components in load-bearing applications or to perform mechanical functions. Improved methods of low-cost 3D printer calibration are needed before their open-design potential can be realized in applications, including 3D-printed orthotics and prosthetics. This paper applies methodologies associated with high-precision CNC machining systems, namely, kinematic error modeling and compensation coupled with standardized test methods from ISO230-4, such as the ballbar for kinematic and dynamic error measurements, to examine the influence and feasibility for use on low-cost CNC/3D printing platforms. Recently, the U.S. Food and Drug Administration’s “Technical considerations for additive manufactured medical devices” highlighted the need to develop standards specific to additive manufacturing in regulated manufacturing environments. This paper shows the benefits of the methods described within ISO230-4 for error assessment, alongside applying kinematic error modeling and compensation to the popular kinematic configuration of an Ultimaker 3D printer. A Renishaw ballbar QC10 is used to quantify the Ultimaker’s errors and thereby populate the error model. This method quantifies machine errors and populates these in a mathematical model of the CNC system. Then, a post-processor can be used to compensate the printing code. Subsequently, the ballbar is used to demonstrate the dramatic impact of the error compensation model on the accuracy and contouring of the Ultimaker printer with 58% reduction in overall circularity error and 90% reduction in squareness error.
Basites of the Vilyui paleorift: geochemistry and sequence of intrusive events
Authors: Tomshin M.D. , Kopylova A.G. , Konstantinov K.M. , Gogoleva S.S.
Published: October 2018

We present results of study of the basites of the Vilyui paleorift. Their 40Ar/39Ar isotopic ages were used to establish the sequence of their intrusion, which lasted ~ 18 Myr. Dolerite sills of the Kontai–Dzherba zone were the first crystallizing phase (378.0–380.7 Ma), which was followed by the intrusion of dikes of the Vilyui–Markha zone (372–373 Ma). Dikes of the Chara–Sinsk zone were the last crystalizing phase (362–364 Ma). The prolonged plume–lithosphere interaction resulted in the successive enrichment of basaltic melt with titanium, phosphorus, REE, HSFE, and LILE. Accumulation of the melt and formation of a magmatic lens at the crust-mantle boundary led to early crystallization of the melt at a depth of 35–40 km from the paleosurface under reducing conditions at a temperature of 1450–1470 °C. We assume that the inception and sequent opening of the Vilyui paleorift were associated with the relative rotation of 22° of the Angara–Anabar block with respect to the Aldan block in Early Famennian time. The Euler pole of rotation was located in the southern part of the paleorift, and a melting zone was directly beneath it.
Prospects of search for diamondiferous kimberlites in the northeastern Siberian Platform
Authors: Sobolev N.V. , Sobolev A.V. , Tomilenko A.A. , Kuz’min D.V. , Grakhanov S.A. , Batanova V.G. , Logvinova A.M. , Bul’bak T.A. , Kostrovitskii S.I. , Yakovlev D.A. , Fedorova E.N. , Anastasenko G.F. , Nikolenko E.I. , Tolstov A.V. , Reutskii V.N.
Published: October 2018

The objects of study are Triassic hypabyssal diamondiferous kimberlites with an age of 220–245 Ma, containing macrocrysts of unaltered olivine. The latter are close in the time of formation to the main stage of intrusion of the Siberian Trap Province (252 Ma), which lasted less than 1 Myr. A comparative high-precision analytical study of the Ti, Ca, Cr, and Al impurity patterns in about 1000 olivine macrocryst samples with a forsterite content Fo = (100Mg/(Mg + Fe)) of 78 to 93 has demonstrated the effect of traps on the lithospheric composition. A comprehensive comparative study of diamonds from northern placers and Triassic kimberlites, including determination of their carbon isotope composition, was performed. Chromatography–mass-spectroscopic analysis of submicron fluid inclusions in diamonds from northern placers and kimberlites has shown predominant hydrocarbons of a wide range of compositions and subordinate contents of N2, H2O, and CO2. These findings, together with the results of previous studies of subcalcic Cr-pyropes and diamonds found in the Lower Carboniferous gritstones of the Kyutyungde graben, lead to the conclusion that the Toluopka kimberlite field is promising for Paleozoic kimberlites. The results of comprehensive studies of diamonds and indicator minerals and U/Pb isotope dating of numerous detrital zircon samples from the basal horizon of the Carnian Stage (Upper Triassic) of the Bulkur site in the lower reaches of the Lena River suggest the presence of diamondiferous kimberlites within the northeastern Siberian Platform. The age of the probable primary diamond sources in the study area can be evaluated by an integrated U/Pb isotope dating of zircons, perovskites, and rutiles from the developed diamond placers and the basal horizon of the Carnian Stage.