bluuebunny/crossref_metadata_2025 huggingface dataset:
Altered embryotrophic capacities of the bovine oviduct under elevated free fatty acid conditions: an in vitro embryo­–oviduct co-culture model
Authors: Jordaens L. , van Hoeck V. , Pintelon I. , Thys S. , Bols P. E. J. , Marei W. F. A. , Leroy J. L. M. R.
Published: February 2020

Maternal metabolic stress conditions are of growing importance in both human and dairy cattle settings as they can have significant repercussions on fertility. Upregulated lipolysis is a common trait associated with metabolic disorders and results in systemically elevated concentrations of non-esterified fatty acids (NEFAs). The effects of high NEFA concentrations on the follicular environment, oocyte and embryo development is well documented. However, knowledge on the effects of NEFAs within the oviduct, representing the initial embryonic growth environment, is currently lacking. Therefore, the experiments outlined here were designed to obtain fundamental insights into both the direct and indirect interactions between NEFAs, bovine oviductal cells and developing zygotes. Hence, zygotes were co-cultured with NEFA-pre-exposed bovine oviductal cells or subjected to simultaneous NEFA exposure during the co-culture period. The outcome parameters assessed were embryo development with cleavage (48h post insemination (pi)), morula (120–126h pi) and blastocyst (192h pi) rates, as well as morula intracellular lipid content and blastocyst quality using Bodipy and differential staining respectively. Our data suggest a direct embryotoxicity of NEFAs as well as impaired embryo development through a reduced oviductal ability to support and protect early embryo development.
Opposite effects of high- and low-dose di-(2-ethylhexyl) phthalate (DEHP) exposure on puberty onset, oestrous cycle regularity and hypothalamic kisspeptin expression in female rats
Authors: Yu Zhen , Wang Fan , Han Junyong , Lu Rongmei , Li Qian , Cai Liangchun , Li Bishuang , Chen Jinyan , Wang Kun , Lin Wenjin , Lin Qinghua , Chen Gang , Wen Junping
Published: February 2020

Di-(2-ethylhexyl) phthalate (DEHP) is ubiquitous in the environment and has been proposed to lead to reproductive disruption. In this study, we systematically investigated the effects of different doses of DEHP exposure on female hypothalamic–pituitary–gonadal axis development. Female Sprague–Dawley rats were gavaged with vehicle (corn oil) or DEHP (5 or 500mgkg–1 day–1) during postnatal Days (PNDs) 22–28 or PNDs 22–70. Results demonstrated that the low and high doses of DEHP exerted opposite effects on puberty onset, circulating luteinising hormone, serum oestradiol and progesterone levels, with the low dose (5mgkg–1) promoting and the high dose (500mgkg–1) inhibiting these parameters. Significant dose-related differences were also found in the D500 group with longer oestrous cycle duration, lower ovarian/bodyweight ratio, fewer corpus lutea and more abnormal ovarian stromal tissue in comparison with the oil or D5 groups. Molecular data showed that the hypothalamic Kiss1 mRNA expression in the anteroventral periventricular but not in the arcuate nucleus significantly decreased in the D500 rats and increased in the D5 rats relative to the rats in the oil group. These findings suggested that the kisspeptin system is a potential target for DEHP to disrupt reproductive development and function.
The Ordovician graptolite subfamily Kinnegraptinae in Victoria, Australia
Authors: VandenBerg A.H.M.
Published: February 2020

Victoria is emerging as the region where members of the Ordovician graptolite subfamily Kinnegraptinae, revised herein, reached its highest diversity, with 16 or 17 species present, grouped in the four genera Paradelograptus Erdtmann et al. (1987), Lignigraptus n. gen., Wuninograptus Ni, 1981 and Psenograptus n. gen. The biostratigraphic range of the subfamily extends over much of the Early and Middle Ordovician, from the late Tremadocian Aorograptus victoriae Biozone to the late Darriwilian Archiclimacograptus riddellensis Biozone. Species described are Paradelograptus antiquus (T.S. Hall, 1899a), P. pritchardi (T.S. Hall, 1899a), P. bulmani (Thomas, 1973), P. maletzi n. sp., P. orthae n. sp., P. cayleyi n. sp., Lignigraptus chapmani (Keble & Harris, 1934), L. sedecimus (Harris & Thomas, 1938a), L. ramulosus (Harris & Thomas, 1938a), L. erdtmanni (Rickards & Chapman, 1991), L. gnomus n. sp., L. absidatus n. sp., L. daangean n. sp., L. diabolus n. sp., Wuninograptus quadribrachiatus Ni, 1981, Psenograptus costermansin. sp., Psenograptus sp. A and Psenograptus sp. B. The term glossa is proposed for the elongate apparatuses that adorn thecal apertures of Kinnegraptus, Lignigraptus and Wuninograptus.
Seasonal changes in wildland firefighter fitness and body composition
Authors: Gaskill Steven E. , Dumke Charles L. , Palmer Charles G. , Ruby Brent C. , Domitrovich Joseph W. , Sol Joseph A.
Published: February 2020

Hiking with a pack is the highest-intensity task that wildland firefighters (WLFFs) perform during sustained activities related to wildland fire suppression. Firefighters perform this and other tasks together as a crew; this provides a unique model to evaluate select physical and physiological changes in members of working crews over a fire season during extended operations. The objective of this study was to evaluate changes in peak aerobic fitness (VO2peak), sustainable aerobic fitness at the ventilatory threshold (VO2vt) and body composition over a 5-month wildland fire season. WLFFs from four crews (55 males, 10 females) participated in a maximal graded exercise treadmill test and body composition evaluation pre- and post season. VO2peak values and variance did not change across the fire season (pre=3.96±0.65, post=3.96±0.69Lmin−1, not significant). VO2vt average decreased slightly while variance decreased greatly within each crew (pre=37.5±7.0, post=35.4±2.3mLkg−1 min−1, P<0.05). There was an improvement in VO2vt in initially less-fit WLFFs and a VO2vt decrease in initially more-fit WLFFs. WLFFs lost fat mass (−1.56±−1.06kg, P<0.01) and fat-free mass (−0.38±−1.24kg, P<0.05). Post-season VO2vt values were the same as the higher range of the documented metabolic cost of uphill load carriage and reveal a unique group adaptation to extended physical demands.
Entextualizing and contextualizing the status quo in domestic violence narratives
Authors: Andrus Jennifer
Published: February 2020

Victim/survivors of domestic violence are asked to tell their stories many times, in different contexts, and for
different audiences. These stories are contextualized for the new context and audience at the same time that they become texts –
entextualization – in that context. This article argues that narrative is produced via the co-processes of entextualization and
contextualization (Silverstein & Urban, 1996). The co-processes of
entextualization/contextualization in domestic violence narratives about staying and leaving violent relationships produce stories
that comport with the status quo, as it is envisioned in the stories of the victim/survivors. Using staying/leaving stories of
domestic violence victim/survivors, I show that entextualizations/contextualizations are (1) socioculturally saturated processes
and (2) rhetorical arguments. I argue that narratives entextualize/contextualize events of domestic violence in ways that involve
and comply with the status quo. Ultimately, these processes create discursive resources that reinforce domestic violence.
Decreased running economy is not associated with decreased force production capacity following downhill running in untrained, young men
Authors: Lima Leonardo C. R. , Nosaka Kazunori , Chen Trevor C. , Pinto Ronei S. , Greco Camila C. , Denadai Benedito S.
Published: February 2020

The present study investigated the relationships between changes in running economy (RE) and indirect muscle damage markers following downhill running (DHR) to test the hypothesis that decreased RE after DHR would be associated with decreases in muscle function. Forty‐five young men ran downhill (−15%) for 30 min at the velocity corresponding to 70% of their peak oxygen uptake (VO2peak). Oxygen uptake (VO2) and other parameters possibly associated with RE (blood lactate concentration, perceived exertion, stride length and frequency) were measured during 5‐minute level running at the velocity corresponding to 80%VO2peak before, immediately after and 1–3 days after DHR. Knee extensor maximal voluntary contraction torque (MVC), rate of torque development, vertical jump performance, muscle soreness and serum creatine kinase activity were assessed at the same time points. The values of the dependent variables were compared among time points by one‐way ANOVAs followed by Bonferroni post‐hoc tests when appropriate. Pearson's correlation tests were used to examine relationships between changes in VO2 (RE parameter) and changes in muscle damage parameters. VO2 during the level run increased (p < 0.05) immediately after DHR (18.3 ± 4.6%) and sustained until 2 days post‐DHR (11.7 ± 4.2%). MVC decreased (p < 0.05) immediately (−21.8 ± 6.1%) to 3 days (−13.6 ± 5.9%) post‐DHR, and muscle soreness developed 1–3 days post‐DHR. The magnitude of changes in VO2 did not significantly (p < 0.05) correlate with the changes in muscle damage makers (r = −0.02–0.13) nor stride length (r = −0.05) and frequency (r = −0.05). The absence of correlation between the changes in VO2 and MVC suggests that strength loss was not a key factor affecting RE.
Small extracellular vesicles derived from human mesenchymal stromal cells prevent group 2 innate lymphoid cell‐dominant allergic airway inflammation through delivery of miR‐146a‐5p
Authors: Fang Shu‐Bin , Zhang Hong‐Yu , Wang Cong , He Bi‐Xin , Liu Xiao‐Qing , Meng Xiang‐Ci , Peng Ya‐Qi , Xu Zhi‐Bin , Fan Xing‐Liang , Wu Zhang‐Jin , Chen Dong , Zheng Lei , Zheng Song Guo , Fu Qing‐Ling
Published: February 2020

Group 2 innate lymphoid cells (ILC2s) are recently reported to play a more critical role in allergic diseases. We previously identified that mesenchymal stromal cells (MSCs) elicited therapeutic effects on allergic airway inflammation. Small extracellular vesicles (sEV) derived from MSCs possess striking advantages including low immunogenicity and high biosafety, and is extremely promising cell‐free therapeutic agents. However, the effects of MSC‐sEV on ILC2s are still unclear. Additionally, scalable isolation protocols are required for the mass production of homogenous MSC‐sEV especially in clinical application. We previously reported that induced pluripotent stem cells‐derived MSCs were the ideal cellular source for the large preparation of MSC‐sEV. Here we developed a standardized scalable protocol of anion‐exchange chromatography for isolation of MSC‐sEV, and investigated the effects of MSC‐sEV on ILC2 function from patients with allergic rhinitis and in a mouse ILC2‐dominant asthma model. The characterization of MSC‐sEV was successfully demonstrated in terms of size, morphology and specific markers. Using flow cytometry and human Cytokine Antibody Array, MSC‐sEV but not fibroblasts‐sEV (Fb‐sEV) were found to significantly inhibit the function of human ILC2s. Similarly, systemic administration of MSC‐sEV but not Fb‐sEV exhibited an inhibition of ILC2 levels, inflammatory cell infiltration and mucus production in the lung, a reduction in levels of T helper 2 cytokines, and alleviation of airway hyperresponsiveness in a mouse model of asthma. Using RNA sequencing, miR‐146a‐5p was selected as the candidate to mediate the above effects of MSC‐sEV. We next revealed the uptake of ILC2s to MSC‐sEV, and that transfer of miR‐146a‐5p in MSC‐sEV to ILC2s in part contributed to the effects of MSC‐sEV on ILC2s in vitro and in a mouse model. In conclusion, we demonstrated that MSC‐sEV were able to prevent ILC2‐dominant allergic airway inflammation at least partially through miR‐146a‐5p, suggesting that MSC‐sEV could be a novel cell‐free strategy for the treatment of allergic diseases.
Dynamical response of a neuron–astrocyte coupling system under electromagnetic induction and external stimulation*
Authors: Yuan Zhi-Xuan , Feng Pei-Hua , Du Meng-Meng , Wu Ying
Published: February 2020

Previous studies have observed that electromagnetic induction can seriously affect the electrophysiological activity of the nervous system. Considering the role of astrocytes in regulating neural firing, we studied a simple neuron–astrocyte coupled system under electromagnetic induction in response to different types of external stimulation. Both the duration and intensity of the external stimulus can induce different modes of electrical activity in this system, and thus the neuronal firing patterns can be subtly controlled. When the external stimulation ceases, the neuron will continue to fire for a long time and then reset to its resting state. In this study, “delay” is defined as the delayed time from the firing state to the resting state, and it is highly sensitive to changes in the duration or intensity of the external stimulus. Meanwhile, the self-similarity embodied in the aforementioned sensitivity can be quantified by fractal dimension. Moreover, a hysteresis loop of calcium activity in the astrocyte is observed in the specific interval of the external stimulus when the stimulus duration is extended to infinity, since astrocytic calcium or neuron electrical activity in the resting state or during periodic oscillation depends on the initial state. Finally, the regulating effect of electromagnetic induction in this system is considered. It is clarified that the occurrence of “delay” depends purely on the existence of electromagnetic induction. This model can reveal the dynamic characteristics of the neuron–astrocyte coupling system with magnetic induction under external stimulation. These results can provide some insights into the effects of electromagnetic induction and stimulation on neuronal activity.
Induced superconducting pair correlations in a quasicrystal coupled to a BCS superconductor
Authors: Rai Gautam , Haas Stephan , Jagannathan A
Published: February 2020

We investigate the superconducting pair correlations induced within a 1D quasiperiodic chain when placed in contact with a superconductor. We show that these decay as a power law with distance from the interface. We also show that the induced correlations carry information on the topological properties of the spectrum of the quasiperiodic chain.
Entangling power of multipartite unitary gates
Authors: Linowski Tomasz , Rajchel-Mieldzioć Grzegorz , Życzkowski Karol
Published: February 2020

We study the entangling properties of multipartite unitary gates with respect to the measure of entanglement called one-tangle. Putting special emphasis on the case of three parties, we derive an analytical expression for the entangling power of an n-partite gate as an explicit function of the gate, linking the entangling power of gates acting on the n-partite Hilbert space of dimension

to the entanglement of pure states in the Hilbert space of dimension

. Furthermore, we evaluate its mean value averaged over the unitary and orthogonal groups, analyze the maximal entangling power and relate it to the absolutely maximally entangled (AME) states of a system with 2n parties. Finally, we provide a detailed analysis of the entangling properties of the three-qubit unitary and orthogonal gates.
CdSe quantum dots (QDs) were synthesized by a hot-bubbling strategy
Authors: Wang Renbao , Sun Qiang , Xu Zhenfeng
Published: February 2020

A hot-bubbling strategy was studied to synthesize CdSe quantum dots. The synthetic parameters including temperature and growth time, were studied to show great influence on the optical properties. At the different reaction time CdSe quantum dots could emit fluorescence of different color, ranging from green to red, under the ultraviolet lamp which had irradiation of 365nm. The size of CdSe quantum dots was adjusted by the temperature and reaction time. CdSe quantum dots with sphalerite structure were prepared by this method.
The research of Oil Producing Evaluation on Northern-2 Daqing Blocks and Solution Scheme
Authors: Zhang Yanyan
Published: February 2020

Among current oil in place in Daqing Oilfield, a large part of which is in oil reservoir of the pilot area on Northern-2 Blocks of Daqing oilfield, whose natural flow potential is very low. A Theoretical Analysis of producing state for the pilot area in west of Northern District of Daqing oilfield is studied to find affecting factors on producing state in reservoir and some renovations are presented, in order to provide theory evidence for effective development in reservoir. Based on evaluation of data points of producing state from 261 wells, the pilot area on Northern-2 District of Daqing oilfield is studied to establish mathematical model of injection-production ratio and water-oil ratio. The paper finds affecting factors on producing state in reservoir and ascertain major limitations on technical policy, in order to provide main measures for effective development in reservoir. The study on the effect of producing state in reservoir of the pilot area in west of Northern District of Daqing oilfield, especially carrying on the theoretical analysis to form a set of reasonable limitation on technical policy, have important directive significance on reservoir development.
Preparation and Properties of Silane Molecular Sieve Supported Composite Polyether Ionic Liquids Catalysts
Authors: Cui Zhongyi , Guo Liying
Published: February 2020

In this work, three composite polyether imidazole ionic liquids (PIILs) supported on molecular sieve (MCM-22) with terminal hydroxyl, carboxyl and amino groups were synthesized with the help of silane coupling agent 3-chloropropyltriethoxysilane (CPTES). They were used for cycloaddition of CO2 and propylene oxide (PO) in a fixed-bed reactor. The results showed that MCM-22-CPTES-HOOC-[PECH-MIM]Cl/[ZnBr2] was the best catalytic properties in this reaction. The conversion rate and selectivity were 92.7% and 82.7%.
Research on Forecasting Technology of Single Base Tower Cost in Transmission Line Engineering
Authors: Du Ying , Zhang Jiyuan , Wang Chao , Wan Mingyong , Zhou Ping , Chen Chao
Published: February 2020

For a long time, the overhead transmission line project budget, completion settlement and financial final accounts are all valued according to the entire line. The project construction management and asset collection have not yet been refined. The management is not separately calculated according to the actual investment of different towers, and cannot be reflected in each base tower. The actual cost level and the accuracy of the cost need to be further improved. Therefore, this paper combines the actual pain points and difficulties of overhead line engineering cost management, and innovatively builds a pricing model based on a single base tower. When the company strengthens the construction drawing budget management, improves the project settlement level, accurately controls risks, and realizes high-quality management of cost management. The level of leanness is of great practical significance.
Effect of microwave radiation on pore structure of SCR denitration catalyst
Authors: Shen Honghong , Gu Qunyin , Wen Daoyuan , Liu Gang , Gao Weijun , Ren Jianxing
Published: February 2020

Based on the background of SCR denitrification technology widely used in pulverized coal utility boilers, the characteristics of denitrification catalysts used in industry were studied. Microwave radiation was used to prepare 8Mn-8Fe/Al2O3 denitrification catalyst by using microwave as an efficient and fast heating method. The results show that microwave irradiation can make the catalyst heated from inside to outside without temperature gradient, make the molecule oscillate rapidly, change the specific surface area and pore structure of the catalyst, thus improving the catalytic activity of the catalyst.
Design and Test of Self-Rescue Safety Belt for Power Line Operation at Heights
Authors: Zhiyong Zhao , Jianzhong Zhang , Yijun Hua , Chunming Fei , Jian Fu , Jianling Wu , Juhua Gao , Huayu Fang
Published: February 2020

The self-rescue ability of electric power workers is of great significance to the safety of workers. However, the current use of safety belts can only ensure that operators do not fall to the ground, but it is not convenient for operators to carry out independent rescue and return to the wire. In this paper, a new type of safety belt design scheme is proposed to improve the self-rescue ability of electric power workers. The biggest difference between this new type of safety belt and the current one is that it integrates a new type of buffer bag, which integrates pedal belt and can help operators change their posture and climb up. Through the test of the safety belt with the new buffer bag, it is found that the new safety belt not only has the basic safety protection ability, but also can effectively assist the operators to carry out self-rescue, which greatly improves the safety protection level of the workers of power lines.
The application of a newly modified numerical global springback compensation method
Authors: Zhang Wenfeng , Xiong Wei , Li Chuan , Lv Yong , Song Xiaohui , Xia Yushan
Published: February 2020

A newly modified numerical global springback compensation methodwas used to simulate the die process in this paper. The numerical approach is given to evaluate the compensation matrix, and the matrix changes according to forming deviations. And GCremedies quasi Newton (QN) method’s sensitivity to initial die contour. To verify its effectiveness, GC, DA and QN have been used to design dies for a series sheet metal parts with cylinder, sphere and saddle shapes. Summarizing simulation and experiment results, the method in general converges faster and more stable.
DFT Study on the Hydrogen Evolution Reaction on CoP(110) Surface
Authors: Cheng Chen , Peng Xingyu , Li Pingbo , Ye Peng , Qi Xueqiang
Published: February 2020

Hydrogen evolution reaction (HER) through water splitting depends on the development of efficient non-noble catalysts, among which the cobalt phosphide has been considered as one of the promising catalyst. Herein, the Gibbs free energy towards HER on CoP(110) surface was studied with density functional theory (DFT) calculation. It can be found that the crystal parameters calculated with both GGA-PBE and GGA-PW91 functionals consist well with the experimental result. The CoP(110) may possess good HER activity since it has good conductivity and appropriate Gibbs free energy (∆GH) for hydrogen adsorption.
Quantitative Evaluation Method of Contract Execution Deviation Risk in Power Spot Market
Authors: Zhang Lin , Wu Yujian , Liu Jian , Li Pengfei
Published: February 2020

In the power spot market, the price risk is the biggest among the power purchase schemes under multiple time scales. Equipment failure, scheduling affairs, external policy adjustment and market fluctuation may cause the deviation of contract execution. This paper analyzes the uncertain risk degree of random variables by identifying risk factors. The probability density of the random variable is analyzed, and the conditional risk-value function of the random variable is established. Finally, based on monte carlo stochastic simulation, risk indicators are used to quantitatively evaluate the risk of power purchase and sale.
Study on Microwave Method for Jet Fuel’s Silver Corrosion Test
Authors: Tong Liping , Ma Jun , Fei Yiwei , Wu Kun
Published: February 2020

In this paper, the mechanism of microwave-catalyzed jet fuel’s silver strip corrosion reaction is analyzed from the perspective of microwave chemistry principle, and the influence of microwave conditions on silver strip corrosion reaction is discussed from the aspects of test time, microwave power, load, etc. The optimal reaction conditions for silver strip corrosion are obtained through orthogonal analysis.
Solvent swelling behaviour of Shenmu-Fugu and Shengli coals
Authors: Wei Yan-Bin , Wei Xian-Yong , Sun Ting-Ting , Zong Zhi-Min
Published: February 2020

Swelling behaviors of Shenmu-Fugu bituminous coal (SFBC) and Shengli lignite (SLL) in various organic solvents were investigated at temperatures ranging from 0 °C to 55 °C. The results show that tetrahydrofuran (THF) has a relatively higher swelling ratio in comparison to other solvents, suggesting that THF likely disrupts coal-coal cross-links between macromolecular network structures in coal. SLL swelled more highly than SFBC in methanol (MA), indicating that MA interacts strongly with specific sites on SLL. Swelling ratios of SFBC in carbon disulfide (CDS), recycle liquefaction solvent (RLS) and initial liquefaction solvent (ILS) are appreciably higher than those of SLL. Coal swelling increases with raising temperature within the temperature range studied (0-55 °C), especially in polar solvent.
Study on adsorption performance of pine needle biochar on rhodamine B
Authors: Li Wenbing , chen Tie , Zhang Zheng , Du Changjun , Wang Guanghua
Published: February 2020

Biochar is regarded as a kind of high-efficiency, environmentally friendly and economical new adsorbent because of its low preparation cost, large specific surface area, developed pore structure and rich surface functional groups. It has broad application prospects in the field of sewage treatment. Using pine massoniana as raw material, the pine needle charcoal was obtained by pyrolysis at 300 °C, and the material was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The dyeing wastewater was simulated with rhodamine B to study the pine needle. The adsorption performance of biochar showed that the adsorption kinetics of rhodamine B and the pseudo-second-order kinetic equation were higher, indicating that the adsorption rate was controlled by liquid membrane diffusion and intraparticle diffusion. The liquid membrane diffusion was main control step.
Preparation of composite catalyst and its catalytic cracking properties of coal tar
Authors: Yang Zhiyuan , Ju Xiaoqian , Ma Zhuanzhuan , Zhao Jingjing , Meng Zhuoyue , Chen Zhiping
Published: February 2020

China is rich in coal resources. Coal tar produced by coal combustion is a large amount of surplus. Naphtha and diesel oil with similar properties to kerosene and diesel oil can be produced by catalytic cracking of coal tar oil. In this article, metal-loaded UiO-66 and Y-type zeolite were synthesized by solution thermal method and microwave assisted method. And a high temperature resistant active component catalyst UiO-66-Y was prepared by compounding the two. According to the GC-MS characterization of the original coal tar and the products after cracking with UiO-66-Y, the results show that part of the aromatic compounds in the coal tar added with catalyst will be decomposed and a large number of light component esters will be synthesized at the same time. It provides a possible way to solve the current energy dilemma.
Detailed description of the mathematical modeling of the catalytic naphtha reforming process dynamics
Authors: Yi Xiaoyang , Zhang Peng , Hu Changlu
Published: February 2020

This work is dedicated to the construction of a kinetic model for the naphtha reforming process. By assembling the components into reactivity based lumps, a new reaction network model rooted on 33 lumps and 101 reactions was studied. The tabu search algorithm was used to determine the global optimal solution. The experimental data from the laboratory scale isothermal reactor was used to investigate the kinetics. By comparing with the test data, the average deviation of the reformed products calculated from the proposed model reached 2.5%.
Investigation of all solid state end-pumped Nd:YAG Q-switched laser
Authors: Juan Liu , Yang Zhang , San-Zhao Wang , Yu Shi , Cai-li Wang
Published: February 2020

High energy 1064 nm Q-switched laser output is obtained by LD array end pumping Nd:YAG. For different divergence angles of fast axis and slow axis of LD array, cylindrical lens and spherical lens are used for beam shaping of LD array. The laser properties of high energy 1064 nm Q-switched laser with pump energy is investigated with different Nd3+ ion doping concentration and different LD temperature. The results indicate that the extremely high gain formed at the end of the laser is easy to generate self-excited oscillation with the increasing of Nd3+ ion doping concentration and the increasing of LD temperature, which eventually results in the saturation of Q-switched laser pulse energy and makes it difficult to improve further. In view of saturation phenomenon of Q-switched laser output, Nd3+ ion doping concentration and LD temperature adjustment is proposed to reduce the absorption rate of laser medium to the pump light, which provides an effective technical means for obtaining high energy end pumped Q-switched pulsed laser. A 77.8mJ and 10 ns 1064 nm laser is generated with the LD temperature of 20 °C and the Nd3+ ion doping concentration of 0.8%, and the corresponding optical conversion efficiency is 13.9%.
Study on Optical Properties and Waveguide Structure Optimization of Semiconductor Lasers with InGaAs Quantum Well
Authors: Gu Lei , Li Lin
Published: February 2020

InGaAs quantum wells (QWs) are grown on GaAs substrates by metal-organic chemieal vapor deposition (MOCVD). Sample grown on substrates (100) oriented 2° off towards <111> exhibits relatively high photoluminescence (PL) intensity and narrow full-width at half-maximum (FWHM). Increasing growth rate leads to the enhancement of PL intensity and decrease of FWHM. Asymmetric waveguide layers are applied to reduce the confinement factor of base mode and increase the loss of higher-order mode.
Propelling torque of the self-adjusting vertical-axis rotor
Authors: Augustyn M.
Published: February 2020

The paper presents an innovative solution of the self-adjusting system of the wind turbine with horizontal axis, consisting of two-blade, carousel rotor with vertical axis and two-position self-adjusting mechanism. The procedure of computing power and propeller torque of rotor with self-adjusting system as a function of the angle of wind attack, the design and principles of operation of the adjusting turbine were presented. And also the proposal to use it as a self-adjusting system on the wind direction and at the same time as a protection of the main rotor HAWT (Horizontal Axis Wind Turbine) against excessive speed in strong winds. The proposed system can replace the most common solution like the directional rudder or the auxiliary wind motor, which generally requires the generator rotor brake.
Identification of impregnated activated carbon used as adsorbent in protective equipment for chemical warfare agent
Authors: Won-In K , Chaiprapa J , Chirawatkul P , Dararutana P
Published: February 2020

It is known that X-rays spectroscopy has been developed to apply to many advantages. In this work, Scanning electron microscope coupled with energy dispersive X-ray spectrometer (SEM-EDS) and synchrotron radiation facilities, such as micro-beam X-ray fluorescent spectroscopy (µ-XRF) and X-ray absorption spectroscopy (XAS) have been carried out to study on impregnated activated carbon samples that have been used as a chemical warfare agent adsorbent in military protective equipment. The elemental composition and distribution of sample surface have been analyzed. Their microstructures were highly porous. The results showed a detection of many kinds of metals, especially chromium (Cr), iron (Fe) and copper (Cu) with different from elemental distribution. It was also detected Cr(VI) which was a carcinogen in some samples. It is proposed that these methods can be used as fingerprint to identify various types of adsorbent.
New Application Area for Nitride Based Ceramics as Optical Materials
Authors: Kurama S , Avcioglu S
Published: February 2020

This study is focused on the production of translucent nitride based ceramics changing different parameters such as additive, starting powder size and sintering conditions. Therefore, two different processes were followed in this research. In first one translucent SiAlON ceramics were improved by controlling specific parameters which were mentioned above. In the second stage, translucent Si3N4 ceramic was obtained also the controlling same parameters. This is a very important result for aerospace and defence industry applications due to these materials high temperature resistivity and mechanical properties.
Simple fabrication of magnetically separable ZnO-based photocatalyst nanocomposites
Authors: Tan Thian Khoon , Khiew PoiSim , Chiu WeeSiong , Chia ChinHua
Published: February 2020

Magnetically recyclable ZnO/Fe3O4 nanocomposite photocatalyst was successfully fabricated through simple mechanical mixing and low calcination temperature. The nanocomposite was characterised by XRD, FESEM, TEM and EDX analysis. The magnetic nanocomposite optimisation, such as photocatalyst loading, doping amount of Fe3O4 nanoparticle into the nanocomposite and sintering temperature were conducted. The optimum loading amount of the ZnO/Fe3O4 nanocomposite was 9.0 wt%. The most favourable amount for Fe3O4 doped was 10 wt% and 300 °C was the value for the sintering temperature. The ZnO/Fe3O4 nanocomposite was successfully extracted by applying magnetic field and able to be reused with no significant change arises in the degradation efficiency.
A new criterion for determination S-N curve of CFRP under tension
Authors: Kalinin A G , Lukyanchuk A A , Pankov A V
Published: February 2020

The article is devoted to development of fatigue failure criterion of the CFRP specimen under fatigue tension loading. The main goal of the current study is to develop a quantitative failure criterion for fatigue damage of a specimen with open hole under tension. In response to this problem, the influence of the following parameters on the stability of the criterion and on its application was determined experimentally: manufacturing technology of a material, the loading conditions during testing. The usage of the failure criterion of thickening in the hole zone made it possible to obtain S-N curve while using the classical criterion does not allow to get a S-N curve at some cases. The application of developed failure criterion of thickening made it possible to reduce the standard deviation of the logarithm of S
lg

N
durability. The dependence of the matrix damage area around the hole from the endurance at different loading levels was obtained according to the results of NDT method.
Atomic structures and scanning tunnelling microscopy of nitrogen-doped carbon nanotubes
Authors: Fujimoto Yoshitaka , Saito Susumu
Published: February 2020

We report on atomic structures, energetics, and scanning tunnelling microscopy images of nitrogen defects in carbon nanotubes (CNTs) based on first-principles density-functional study. As defect configurations in CNTs, not only the substitutional nitrogen defect but also the nitrogen-vacancy complex defects (pyridine-type defects) are considered. The substitutional nitrogen defect is found to be energetically the most stable defect. On the other hand, for the pyridine-type defects, the tetramerized and the trimerized configurations are found to be the possible configurations in energy. The scanning tunnelling microscopy (STM) images for defect configurations in N-doped CNTs are studied, and the various N defects in CNTs are expected to be identified by STM experiments.
Photoelasticity Ray-casting for Residual Stresses in the Axisymmetric Glass Cylinder
Authors: Zhang Xun , Tian Quan , Chen Donghai , Huang Licheng
Published: February 2020

Residual stresses are important index to evaluate the precision molded glass plane. Residual stresses inside a glass cylinder was simulated by Finite Element Method. The circular polariscope was used to compare retardation and isoclinic angle between the simulated residual stresses and the thermal treated glass cylinder. The retardation and isoclinic angle of simulated residual stresses were calculated by Jones calculus. The comparison results show a good agreement.
Technical potentials and costs for reducing global anthropogenic methane emissions in the 2050 timeframe –results from the GAINS model
Authors: Höglund-Isaksson Lena , Gómez-Sanabria Adriana , Klimont Zbigniew , Rafaj Peter , Schöpp Wolfgang
Published: February 2020

Methane is the second most important greenhouse gas after carbon dioxide contributing to human-made global warming. Keeping to the Paris Agreement of staying well below two degrees warming will require a concerted effort to curb methane emissions in addition to necessary decarbonization of the energy systems. The fastest way to achieve emission reductions in the 2050 timeframe is likely through implementation of various technical options. The focus of this study is to explore the technical abatement and cost pathways for reducing global methane emissions, breaking reductions down to regional and sector levels using the most recent version of IIASA’s Greenhouse gas and Air pollution Interactions and Synergies (GAINS) model. The diverse human activities that contribute to methane emissions make detailed information on potential global impacts of actions at the regional and sectoral levels particularly valuable for policy-makers. With a global annual inventory for 1990–2015 as starting point for projections, we produce a baseline emission scenario to 2050 against which future technical abatement potentials and costs are assessed at a country and sector/technology level. We find it technically feasible in year 2050 to remove 54 percent of global methane emissions below baseline, however, due to locked in capital in the short run, the cumulative removal potential over the period 2020–2050 is estimated at 38 percent below baseline. This leaves 7.7 Pg methane released globally between today and 2050 that will likely be difficult to remove through technical solutions. There are extensive technical opportunities at low costs to control emissions from waste and wastewater handling and from fossil fuel production and use. A considerably more limited technical abatement potential is found for agricultural emissions, in particular from extensive livestock rearing in developing countries. This calls for widespread implementation in the 2050 timeframe of institutional and behavioural options in addition to technical solutions.
Mo doped TiO2: impact on oxygen vacancies, anatase phase stability and photocatalytic activity
Authors: Kumaravel Vignesh , Rhatigan Stephen , Mathew Snehamol , Michel Marie Clara , Bartlett John , Nolan Michael , Hinder Steven J , Gascó Antonio , Ruiz-Palomar César , Hermosilla Daphne , Pillai Suresh C
Published: February 2020

This work outlines an experimental and theoretical investigation of the effect of molybdenum (Mo) doping on the oxygen vacancy formation and photocatalytic activity of TiO2. Analytical techniques such as x-ray diffraction (XRD), Raman, x-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) were used to probe the anatase to rutile transition (ART), surface features and optical characteristics of Mo doped TiO2 (Mo–TiO2). XRD results showed that the ART was effectively impeded by 2 mol% Mo doping up to 750 °C, producing 67% anatase and 33% rutile. Moreover, the crystal growth of TiO2 was affected by Mo doping via its interaction with oxygen vacancies and the Ti–O bond. The formation of Ti–O–Mo and Mo–Ti–O bonds were confirmed by XPS results. Phonon confinement, lattice strain and non-stoichiometric defects were validated through the Raman analysis. DFT results showed that, after substitutional doping of Mo at a Ti site in anatase, the Mo oxidation state is Mo6+ and empty Mo-s states emerge at the titania conduction band minimum. The empty Mo-d states overlap the anatase conduction band in the DOS plot. A large energy cost, comparable to that computed for pristine anatase, is required to reduce Mo–TiO2 through oxygen vacancy formation. Mo5+ and Ti3+ are present after the oxygen vacancy formation and occupied states due to these reduced cations emerge in the energy gap of the titania host. PL studies revealed that the electron–hole recombination process in Mo–TiO2 was exceptionally lower than that of TiO2 anatase and rutile. This was ascribed to introduction of 5s gap states below the CB of TiO2 by the Mo dopant. Moreover, the photo-generated charge carriers could easily be trapped and localised on the TiO2 surface by Mo6+ and Mo5+ ions to improve the photocatalytic activity.
Serum cotinine levels and nicotine addiction potential of e-cigarettes: an NHANES analysis
Authors: Rapp Joseph L , Alpert Naomi , Flores Raja M , Taioli Emanuela
Published: February 2020

This study aims to compare serum cotinine levels in e-cigarette and combustible cigarette smokers, in an attempt to quantify the potential chronic nicotine addiction risk that e-cigarettes pose. We analyzed 428 participants in 2015–2016 NHANES: 379 (87.03%) smoked combustible cigarettes alone and 49 (12.97%) smoked e-cigarettes. Serum cotinine levels were measured by isotope-dilution high-performance liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometric method with a detection limit of 0.015 ng/ml. Electronic cigarette smokers were younger than combustible cigarette smokers (mean age 36.79 versus 42.69 years, P = 0.03), more likely to be male (64.93% versus 48.32%, P = 0.09) and significantly less likely to live with other smokers (50.17% versus 90.07%, P < 0.01). Serum cotinine levels increased linearly with self-reported days of smoking in both electronic cigarette and combustible cigarette smokers, after accounting for living with a smoker. The analysis of the subgroup who reported daily use show non-statistically significantly higher serum cotinine levels in electronic cigarette smokers versus combustible cigarette smokers (β adj = 52.50, P = 0.10). This analysis of recent US data demonstrates that electronic cigarettes expose users to nicotine levels proportionate to, and potentially higher than combustible cigarettes, and thus pose a serious risk of chronic nicotine addiction. This could be particularly relevant in otherwise tobacco naive individuals; future risk of tobacco-related dependence, addiction and relapse, as well as of tobacco-related cancers in these subjects needs to be investigated.
Tryptophan levels associate with incident cardiovascular disease in chronic kidney disease
Authors: Konje Vetalise C , Rajendiran Thekkelnaycke M , Bellovich Keith , Gadegbeku Crystal A , Gipson Debbie S , Afshinnia Farsad , Mathew Anna V ,   the Michigan Kidney Translational Core CPROBE Investigator Group
Published: February 2020

Background

Non-traditional risk factors like inflammation and oxidative stress play an essential role in the increased cardiovascular disease (CVD) risk prevalent in chronic kidney disease (CKD). Tryptophan catabolism by the kynurenine pathway (KP) is linked to systemic inflammation and CVD in the general and dialysis population. However, the relationship of KP to incident CVD in the CKD population is unknown.

Methods

We measured tryptophan metabolites using targeted mass spectrometry in 92 patients with a history of CVD (old CVD); 46 patients with no history of CVD and new CVD during follow-up (no CVD); and 46 patients with no CVD history who developed CVD in the median follow-up period of 2 years (incident CVD).

Results

The three groups are well-matched in age, gender, race, diabetes status and CKD stage, and only differed in total cholesterol and proteinuria. Tryptophan and kynurenine levels significantly decreased in patients with ‘Incident CVD’ compared with the no CVD or old CVD groups (P = 5.2E–7; P = 0.003 respectively). Kynurenic acid, 3-hydroxykynurenine and kynurenine are all increased with worsening CKD stage (P < 0.05). An increase in tryptophan levels at baseline was associated with 0.32-fold lower odds of incident CVD (P = 0.000014) compared with the no CVD group even after adjustment for classic CVD risk factors. Addition of tryptophan and kynurenine levels to the receiver operating curve constructed from discriminant analysis predicting incident CVD using baseline clinical variables increased the area under the curve from 0.76 to 0.82 (P = 0.04).

Conclusions

In summary, our study demonstrates that low tryptophan levels are associated with incident CVD in CKD.
NOS1AP polymorphisms reduce NOS1 activity and interact with prolonged repolarization in arrhythmogenesis
Authors: Ronchi Carlotta , Bernardi Joyce , Mura Manuela , Stefanello Manuela , Badone Beatrice , Rocchetti Marcella , Crotti Lia , Brink Paul , Schwartz Peter J , Gnecchi Massimiliano , Zaza Antonio
Published: February 2020

Aims 

NOS1AP single-nucleotide polymorphisms (SNPs) correlate with QT prolongation and cardiac sudden death in patients affected by long QT syndrome type 1 (LQT1). NOS1AP targets NOS1 to intracellular effectors. We hypothesize that NOS1AP SNPs cause NOS1 dysfunction and this may converge with prolonged action-potential duration (APD) to facilitate arrhythmias. Here we test (i) the effects of NOS1 inhibition and their interaction with prolonged APD in a guinea pig cardiomyocyte (GP-CMs) LQT1 model; (ii) whether pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) from LQT1 patients differing for NOS1AP variants and mutation penetrance display a phenotype compatible with NOS1 deficiency.

Methods and results 

In GP-CMs, NOS1 was inhibited by S-Methyl-L-thiocitrulline acetate (SMTC) or Vinyl-L-NIO hydrochloride (L-VNIO); LQT1 was mimicked by IKs blockade (JNJ303) and β-adrenergic stimulation (isoproterenol). hiPSC-CMs were obtained from symptomatic (S) and asymptomatic (AS) KCNQ1-A341V carriers, harbouring the minor and major alleles of NOS1AP SNPs (rs16847548 and rs4657139), respectively. In GP-CMs, NOS1 inhibition prolonged APD, enhanced ICaL and INaL, slowed Ca2+ decay, and induced delayed afterdepolarizations. Under action-potential clamp, switching to shorter APD suppressed ‘transient inward current’ events induced by NOS1 inhibition and reduced cytosolic Ca2+. In S (vs. AS) hiPSC-CMs, APD was longer and ICaL larger; NOS1AP and NOS1 expression and co-localization were decreased.

Conclusion 

The minor NOS1AP alleles are associated with NOS1 loss of function. The latter likely contributes to APD prolongation in LQT1 and converges with it to perturb Ca2+ handling. This establishes a mechanistic link between NOS1AP SNPs and aggravation of the arrhythmia phenotype in prolonged repolarization syndromes.
Atrial septum stenting in a foetus with hypoplastic left heart syndrome and restrictive foramen ovale: an alternative to emergency atrioseptectomy in the newborn—a case report
Authors: Tulzer Andreas , Arzt Wolfgang , Prandstetter Christoph , Tulzer Gerald
Published: February 2020

Background

In patients with hypoplastic left heart syndrome (HLHS) premature closure or restriction of the interatrial communication causes severe cyanosis directly after birth with rapid deterioration in clinical state. An ex-utero intrapartum treatment (EXIT) procedure, extracorporal membrane oxygenation (ECMO), and emergency interventional cardiac catheterization or cardiac surgery has to be anticipated and prepared. We report the first case performing foetal atrial septum stenting in such a patient directly before birth to enable uncomplicated interatrial shunting postnatally.

Case summary

A 31-year-old pregnant woman was referred to our centre for further evaluation of the foetus due to HLHS. In the follow-up study before birth severe restriction of the foramen ovale with increased retrograde flow in the pulmonary veins [0.33 ratio antegrade/retrograde time velocity integral (TVI)] was detected. After careful consideration foetal atrial septum stenting was performed at 38 + 3 weeks of gestation. At 39 + 2 weeks of gestation the baby was born by caesarean section followed by an uncomplicated postnatal adaption. On the 7th day of life a Norwood procedure was performed and the baby was discharged on the 63rd postoperative day.

Discussion

Evaluation of the interatrial communication in foetuses with HLHS should be done carefully just before birth. In the case of severe restriction or closure of the foramen ovale atrial septum stenting just before birth can be considered as an alternative treatment to an EXIT procedure, ECMO, or emergency atrioseptectomy on bypass. However, a very experienced team of paediatric cardiologists and perinatologists with expertise in foetal cardiac interventions is needed to perform this technical difficult procedure.