Inhibition characteristics of circulating current in parallel inverter driving system of mine hoist

This research investigated the outputting circulation current inhibition characteristic which are controlled by the instantaneous feedback voltage in inverter parallel driving of the mine hoist. We established a transfer function of the parallel inverters controlled by the close-loop adjustment of instantaneous voltage feedback. The influence of the parameters of the close-loop feedback circuit to the inhibition effects to the outputting circulation current is observed. After analyzing the circulating current inhibition characteristics, the proportion integration （PI） controller is introduced into the close-loop adjustment by instantaneous voltage feedback. The characteristics equation is gained to determine the PI parameters by drawing the Bode plots. The inhibition effects of the proposed controller are examined by the established simulation model of parallel inverter system. The harmonic distortion rate at the outputting voltage frequency value of 4, 10, 20, 41 and 50 Hz, are all lower than 2.32 % by the instantaneous outputting voltage feedback.

An integrated approach for the optimization of wheel-rail contact force measurement systems

A comprehension of railway dynamic behavior implies the measure of wheel-rail contact forces which are affected by disturbances and errors that are often difficult to be quantified. In this study, a benchmark test case is proposed, and a bogie with a layout used on some European locomotives such as SIEMENS El90 is studied. In this layout, an additional shaft on which brake disks are installed is used to transmit the braking torque to the wheelset through a single-stage gearbox. Using a mixed approach based on finite element techniques and statistical considerations, it is possible to evaluate an optimal layout for strain gauge positioning and to optimize the measurement system to diminish the effects of noise and disturbance. We also conducted preliminary evaluations on the precision and frequency response of the proposed system.

Optimization of Nitrogen Fertilization Input on <i>Zea mays</i>L. Cultivation through the Biological Inhibition of Nitrification

Introduction: Nitrogen (N) fertilizer is the most widely used fertilizer (300 - 350 Kg/Ha) on the corn plant, mean while it has mobile character, so it becomes the lowest utilization (40% - 50%) compared to other nutrient elements. Aims: The aim of this research is to examine the effect of various qualities and dose of litter on the dynamics of N mineral soil and soil nitrification potential on maize cultivation system. Method: The treatment is set by Randomized Completely Block Design (RCBD). Four kinds of litter is chosen to represent the groups of low quality (Tectona grandis and Pterocarpus indicus) and the groups of high quality (Oryza sativa and Eupatorium inulifolium) are given on four doses: 4, 8, 12 and 16 mg/Ha. All treatments are fertilized with urea 150 kg/Ha. Variables measured include the soil concentration of NH4- and NO3-, potential nitrification conducted in 2, 4, 6, 8 and 10 weeks after planting the corn. Result: The research shows that the addition of low-quality litter is influenced very significantly by release of NH4-, formation of NO3- and potential nitrification of soil. Others results show that the content of litter (lignin, polyphenol and C/N ratio) has the most powerful influence as regulator of NH4- released (p NO3- (p < 0.01) and potential nitrification of soil (p < 0.01) rather than the content of lignin, polyphenol and C/N ratio of litter separately. Conclusion: The conclusion of this research is that the management of litter quality input can be applied in the field to regulate the process of nitrification in soil and potential to increase N used efficiency of corn plant.

On the Period Variation of the W UMa-type Contact Binary V502 Ophiuchi

The variation in the orbital period of the W UMa type contact binary V502 Oph is analyzed. The orbital period exhibits a wavelike variation with a periodicity of 23.0 years and an amplitude of AP = 1.24 ×10^-5 days superimposed on secular decrease of dP/dt = 1.68× 10^-7 day per year. The long-term decrease may be accompanied by the contraction of the secondary at a rate of 83 m per year and a mass transfer rate from the primary to the secondary of 4.28×10^-8M· per year. The short-term oscillation may be explained by the presence of a third component. Orbital elements of the third body and its possible mass are presented.

厌氧-好氧法处理特种有机工业废水的动态模拟实验

采用絮凝、毒性及生化试验，确定了废水处理最佳工艺流程，研究了浓度、停留时间对ＣＯＤ去除率的影响．结果表明，该有机废水采用絮凝净化效果不大，且对生化处理具有一定的抑制作用，当系统进水ＣＯＤ为 ３０００ｍｇ／Ｌ，流量为１Ｌ／ｈ时；经过厌氧、两级好氧处理后，出水中ＣＯＤ可降至１５０ｍｇ／Ｌ以下，总去除率可达９５％以上，达到了工业废水排放标准．

小鼠Wnt-3a基因在NIH3T3细胞中的表达及其活性的初步分析

目的:表达具备生物活性的重组小鼠Wnt-3a信号蛋白.方法:应用脂质体转染试剂将重组真核表达载体pSecTag2/HygroB-Wnt3a转染并筛选稳定表达的NIH3T3细胞,WesternBlot鉴定重组Wnt-3a蛋白的表达,并对Wnt3a/NIH3T3细胞的融合密度及抗凋亡能力给予检测.结果:Wnt-3a信号蛋白在Wnt3a/NIH3T3细胞中获得稳定表达,Wnt-3a信号蛋白能够明显提高NIH3T3细胞的融合密度及抗凋亡能力.结论:在NIH3T3细胞中表达的重组Wnt-3a信号蛋白具备生物活性.

接触抑制对转化生长因子β诱导基因22(TSC-22)在心脏成纤维细胞中表达的影响

目的通过建立体外原代培养的新生大鼠心脏成纤维细胞模型,研究接触抑制对TSC-22表达的影响,并为进一步探明TSC-22在心脏成纤维细胞中的确切功能奠定基础。方法采用差速贴壁法原代分离培养Sprague-Dawley大鼠心脏成纤维细胞,分别进行下述实验:①以不同初始密度接种细胞,分为两组:A组为50%融合组:以1.0×105/ml密度接种细胞于T25细胞培养瓶中,培养24h;B组为100%融合组:以2.0×105/ml密度接种细胞于T25细胞培养瓶中,培养24h;②均以2.0×105/ml的初始密度接种细胞于T25细胞培养瓶中,分为4组:A组为未融合组:接种后培养6h(至贴壁未融合状态);B组为融合组:接种后培养24h(至100%融合状态);C组为胰酶消化打破融合组:接种后培养至100%融合后,0.25%胰酶消化,离心混悬后重新贴壁,继续培养6h(此时细胞重新贴壁但未融合);D组为胰酶消化重新达融合组:接种后培养至100%融合后,0.25%胰酶消化,离心混悬后重新贴壁,继续培养24h(此时细胞重新达到100%融合)。以上各组分别提取mRNA和蛋白,应用实时定量PCR(real-time PCR)、蛋白印记(Western blotting)法分别检测TSC-22 mRNA、蛋白表达的变化。结果实时定量RT-PCR和蛋白印记结果表明:①心脏成纤维细胞融合度达到100%,即发生接触抑制时,与50%融合度组相比,TSC-22的mRNA和蛋白水平水平均显著升高(P<0.05);②融合组心脏成纤维细胞与未融合组相比,TSC-22的mRNA和蛋白水平均显著升高;胰酶消化打破融合组心脏成纤维细胞与融合组相比,TSC-22的mRNA和蛋白水平均显著下降;胰酶消化重新达融合组成纤维细胞与胰酶消化打破融合组相比,TSC-22的mRNA和蛋白水平均显著升高(P均<0.05)。结论本实验结果明确表明,在体外培养的心脏成纤维细胞中,接触抑制是诱导TSC-22表达升高的重要因素。当心脏成纤维细胞发生接触抑制时,TSC-22可能通过行使其转录因子的生物学功能,在接触抑制后所触发的信号通路中发挥重要调控作用。对TSC-22确切功能的深入研究,将有助于进一步理解和阐明心脏重构机制。

Evolution of the electrical contact of dynamic pantograph–catenary system

A good contact between the pantograph and catenary is critically important for the working reliability of electric trains, while the basic understanding on the electrical contact evolution during the pantograph--catenary system working is still ambiguous so far. In this paper, the evolution of electric contact was studied in respects of the contact resistance, temperature rise, and microstructure variation, based on a home-made pantograph-catenary simulation system. Pure carbon strips and copper alloy contact wires were used, and the experimental electrical current, sliding speed, and normal force were set as 80 A, 30 km/h, and 80 N, respectively. The contact resistance presented a fluctuation without obvious regularity, concentrating in the region of 25 and 50 mf~. Temperature rise of the contact point experienced a fast increase at the first several minutes and finally reached a steady state. The surface damage of carbon trips in microstructure analysis revealed a complicated interaction of the sliding friction, joule heating, and arc erosion.

Kinetics of Asymmetric Reduction of Phenylglyoxylic Acid to R-(-)-Mandelic Acid by Saccharomyces Cerevisiae FD11b

The kinetics of asymmetric production of R-（-）-mandelic acid （R-MA） from phenylglyoxylic acid （PGA） catalyzed by Saccharomyces cerevisiae sp. strain FD11b was studied by fed-batch cultures. The concentrations of glucose and PGA were controlled respectively with a dual feeding system. When the electron donor glucose was supplied at the rate of 0.0833mmol·gdw^-1·h^-1, the specific production rate （qp） and the enantiomeric excess of R-MA reached the maximum 0.353mmol·gdw^-1·h^-1 and 97.1%, respectively. The apparent reduction activity of yeast FD 11 b was obviously affected by both substrate PGA and product MA. The qp value reached the maximum 0.36-0.38mmol·gdw^-1·h^-1 when the PGA concentration was controlled between 25 and 35mmol·L^-1. The obvious substrate inhibition of bioconversion was observed at the PGA concentrations higher than 40mmol·L^-1. The accumulation of product MA also caused a severe feed-back inhibition for its production when the product concentration was above 60mmol·L^-1. The kinetic model with the inhibition effect of both substrate and product was simulated by a computer-based least-square arithrnatic. The established kinetic model was in good agreement with the experimental data.

Normal Human Cell Conversion to 3-D Cancer-like Growth: Genome Damage, Endopolyploidy, Senecence Escape, and Cell Polarity Change/Loss

In cell cultures monolayered cell growth is controlled by contact inhibition which again is controlled by the cell polarity system by always being positioned in accord with the cytoskeleton axis. Presently, cycling endopolyploid cells (tetraploidy) were shown to undergo perpendicular divisions relative to the cytoskeleton axis which disrupted to some degree contact inhibition in the near-senescent phase of human primary cells. These experiments included genome damage-induced endopolyploidization (TAS-treated) to simulate as a model system the state of in vivo accelerated cell senescence (ACS) which is induced by therapy-associated genomic damage. From ACS delayed tumor re-growth (re-lapse) occurs from “robust” cell propagation, but mechanisms for such cell escape from senescence are unknown. For TAS-treated a karyoplast bud-off process with change to limited mitotic activity occurred in young senescent cultures. In old, deep senescent (5 - 8 weeks) cultures, unexpectedly escape cell-growth showed three dimensional (3-D) tumor-like spheres from growths of morphologically different cells as compared to the fibroblastic phenotype. These cells expressed cell polarity change, and very condensed nuclei were variously perpendicularly oriented to what-ever cell polarity was present. These results were discussed in regard to in vivo relapse and, to the importance of cell polarity change in tumorigenesis. Induced senescence as an anti-tumor mechanism in therapy treatment becomes a questionable procedure from the present experimental results.

Investigation on the factors influencing the thickness distribution of superplastic-formed components

In the superplastic sheet forming process, the uniformity of the sheet's final thickness distribution is vital for ensuring the good mechanical quality of the formed components. The influences of the component shape and the contact friction on the final thickness distribution were investigated in this work by using finite element method on a series of axisymmetric models. It was concluded that shape optimization and friction elimination are required to get uniform thickness distribution, and eventually to improve the mechanical quality of the formed components. The constitutive equation of the Ti-6A1-4V superplastic material was also determined on the basis of experimental data.

Cl^-对接触辉光放电等离子体降解阳离子蓝的影响

本文研究了Cl-对接触辉光放电等离子体(CGDP)降解阳离子蓝(CB)的影响.结果表明:以5.2mS/cm Na2SO4为电解质时,放电电压为500V,放电90min,CB脱色率为77.92%;当NaCl浓度为0~1.4g/L时,降解率随NaCl浓度的增大而减小;当NaCl浓度高于1.4g/L时,降解率随NaCl浓度的增大而增大,NaCl浓度提高到2.4和3.2g/L时,放电90min,CB脱色率分别为91.12%和98.41%.实验同时考察了Cl-对降解CB过程中生物毒性的变化.3.2g/LNaCl为电解质时,放电90min,降解液对发光菌的抑制率从最初92.20%减小为10.68%,远低于电解质为Na2SO4时的抑制率(54.91%).由此可以看出,较高浓度Cl-不仅能有效加快CB的降解过程,同时也能明显降低CB在降解过程中的生物毒性.

β-环糊精-透明质酸改性pHEMA角膜接触镜水凝胶的制备与性能

利用β-环糊精-透明质酸(β-CD-crHA)对聚甲基丙烯酸羟乙酯(pHEMA)水凝胶进行改性研究。借助核磁共振波谱仪、红外光谱仪、原子力显微镜、接触角仪、紫外-可见分光光度计、电子万能试验机等对水凝胶的组成、表面形貌、水接触角、透光率、拉伸性能、泪液蛋白吸附、双氯芬酸负载与释放等性能进行表征。结果表明,β-CD-crHA含量的增加显著提高了pHEMA水凝胶的表面亲水性,有效抑制了溶菌酶和牛血清白蛋白的吸附,同时增加了pHEMA水凝胶对双氯芬酸的负载量并减缓其释放速率,但不降低其透光率、拉伸应变等基本性能,是一种有前景的角膜接触镜材料。

Crystal Structures of Urokinase-type Plasminogen Activator in Complex with 4-(Aminomethyl) Benzoic Acid and 4-(Aminomethyl-phenyl)-methanol

Urokinase-type plasminogen activator （uPA） is a trypsin-like serine protease and plays a key role in several biological processes, including tissue remodeling, cell migration, and matrix degradation. The inhibitors of uPA have been shown to prevent the spread of metastasis and tumor growth, and accordingly uPA is widely recognized as a target for the treatment of cancer. In this work, we report the crystal structures of the complexes of uPA with its inhibitors： 4- （aminomethyl）-benzoic acid （AMBA） and 4-（aminomethyl-phenyl）-methanol （AMPM）, both at a resolution of 2.35 А. The inhibitory constants of these two inhibitors were measured by a chromogenic competitive assay, and it was found that AMBA is a better inhibitor for uPA （Ki = 2.68 mM） than AMPM （Ki = 13.99 mM）. The structural study shows that the binding mode of inhibitor AMBA on uPA is similar to that of AMPM on uPA, both docked into the active site S1 pocket of uPA. Structural details of these complexes are provided to explain the difference of inhibitory constants.

Laryngopharyngeal reflux disease management for recurrent laryngeal contact granuloma:A case report

BACKGROUND Laryngeal contact granuloma(LCG)is difficult to treat and frequently associated with high persistence and recurrence,despite the availability of both surgical and pharmacological treatment options.An appropriate strategy is therefore needed to help patients with multiple recurrences of LCG to potentially avoid unnecessary surgery.CASE SUMMARY We describe the case of a 34-year-old male patient with recurrent LCG in which a good response was achieved through successful management of laryngopharyngeal reflux disease using a combination pharmacotherapeutic regimen consisting of anti-reflux therapy,pepsin secretion inhibition,bile acid neutralization,and lifestyle modifications.This patient underwent surgery to excise the granuloma,then relapsed,underwent a second surgery,which was followed by a second recurrence.The granuloma then disappeared after 9 mo of combined treatment with ilaprazole enteric-coated capsules(10 mg qd),mosapride tablets(5 mg tid)and compound digestive enzyme capsules(2 tablets).The drug regimen was discontinued after one year,and no recurrence of the lesion has been reported during the one-year follow-up period.CONCLUSION We report a combination of pharmacotherapeutics and lifestyle modifications for the management of laryngopharyngeal reflux disease to address recurring LCG.

Synthesis and Herbicidal Activity of 5-Heterocycloxy-3-substituted-1-(3-trifluoromethyl)phenyl-1H-pyrazole

The authors synthesized a series of novel 5-heterocycloxy-3-substituted-1-（3-trifluoromethyl）phenyl-1H- pyrazole derivatives. Herbicidal activities of the two intermediate compounds and thirteen target compounds were evaluated via Brassica napus and Echinochloa crusgalli（L.） Beauv tests. Bioassay results show that some of the compounds exhibit better inhibiting activities against Brassica napus and some of the compounds exhibit bleaching activities against Echinochloa crusgalli（L.） Beauv at 100 μg/mL.

Visualizing DC morphology and T cell motility to characterize DC-T cell encounters in mouse lymph nodes under mTOR inhibition

Mammalian target of rapamycin(mTOR),a serine/threonine kinase orchestrating cellular metabolism,is a crucial immune system regulator.However,it remains unclear how mTOR regulates dendritic cell(DC) function in vivo,especially DC-T cell encounters,a critical step for initiating adaptive immune responses.We dynamically visualized DC-T contacts in mouse lymph node using confocal microscopy and established an encounter model to characterize the effect of mTOR inhibition on DC-T cell encounters using DC morphology.Quantitative data showed mTOR inhibition via rapamycin altered DC shape,with an increased form factor(30.17%) and decreased cellular surface area(20.36%) and perimeter(22.43%),which were associated with Cdc42 protein downregulation(52.71%).Additionally,DCs adopted a similar morphological change with Cdc42 inhibition via ZCL278 as that observed with mTOR inhibition.These morphologically altered DCs displayed low encounter rates with T cells.Time-lapse imaging data of T cell motility supported the simulated result of the encounter model,where antigen-specific T cells appeared to reduce arrest in the lymph nodes of rapamycin-pretreated mice relative to the untreated group.Therefore,mTOR inhibition altered DC morphology in vivo and decreased the DC-T cell encounter rate,as well as Cdc42 inhibition.By establishing an encounter model,our study provides an intuitive approach for the early prediction of DC function through morphological quantification of form factor and area.

The VAMP-associated protein VAP27-1 plays a crucial role in plant resistance to ER stress by modulating ER–PM contact architecture in Arabidopsis

The endoplasmic reticulum(ER)and the plasma membrane(PM)form ER–PM contact sites(EPCSs)that allow the ER and PM to exchange materials and information.Stress-induced disruption of protein folding triggers ER stress,and the cell initiates the unfolded protein response(UPR)to resist the stress.However,whether EPCSs play a role in ER stress in plants remains unclear.VESICLE-ASSOCIATED MEMBRANE PROTEIN(VAMP)-ASSOCIATED PROTEIN 27-1(VAP27-1)functions in EPCS tethering and is encoded by a family of 10 genes(VAP27-1–10)in Arabidopsis thaliana.Here,we used CRISPR-Cas9-mediated genome editing to obtain a homozygous vap27-1 vap27-3 vap27-4(vap27-1/3/4)triple mutant lacking three of the key VAP27 family members in Arabidopsis.The vap27-1/3/4 mutant exhibits defects in ER–PM connectivity and EPCS architecture,as well as excessive UPR signaling.We further showed that relocation of VAP27-1 to the PM mediates specific VAP27-1-related EPCS remodeling and expansion under ER stress.Moreover,the spatiotemporal dynamics of VAP27-1 at the PM increase ER–PM connectivity and enhance Arabidopsis resistance to ER stress.In addition,we revealed an important role for intracellular calcium homeostasis in the regulation of UPR signaling.Taken together,these results broaden our understanding of the molecular and cellular mechanisms of ER stress and UPR signaling in plants,providing additional clues for improving plant broad-spectrum resistance to different stresses.

Spontaneous escape behavior of silver from graphite-like carbon coating and its inhibition mechanism

A series of silver-doped graphite-like carbon coatings was prepared on the surface of aluminum alloy using the magnetron sputtering method. The spontaneous escape behavior and inhibition mechanism of silver from graphite-like carbon coating were studied. The results showed that when the sample prepared with a 0.01-A current on the silver target was placed in an atmospheric environment for 0.5 h, an apparent silver escape phenomenon could be observed. However, the silver escape phenomenon was not observed for samples prepared with a 0.05-A current on the silver target if the sample was retained in a 10^（-1） Pa vacuum environment, even after 48 h. Compared with the sample placed in the atmospheric environment immediately after an ion plating process, the silver escape time lagged for 6 h. Nanometer-thick pure carbon coating coverage could effectively suppress silver escape. When the coating thickness reached700 nm, permanent retention of silver could be achieved in the silver-doped graphite-like carbon coating.As the silver residue content in the graphite-like carbon coating increased from 2.27 at.% to 5.35 at.%, the interfacial contact resistance of the coating decreased from 51mΩcm^2 to 6 mΩcm^2.

细辛醚对6种农业害虫的杀虫活性

【目的】进一步确定细辛醚的杀虫作用。【方法】在不同作用方式下测定了细辛醚对粘虫、桃蚜、菜青虫、棉铃虫、玉米象和赤拟谷盗等6种农业害虫的室内毒力。【结果】细辛醚对粘虫、桃蚜和菜青虫24 h的触杀LD50值分别为35.06,1.11,66.28μg/头,在供试剂量下对棉铃虫、玉米象和赤拟谷盗成虫的触杀作用较差;对粘虫和玉米象的熏蒸LC50值分别为16.92(12 h)和7.53(72 h)μL/L;对玉米象有一定的忌避作用,忌避作用随时间延长而减弱;细辛醚质量浓度为1,5和10 mg/g的处理,33 d对玉米象的致死率分别为26.97%,86.51%和100%,1,5 mg/g处理33 d和76 d对玉米象种群抑制率分别为74.18%和96.54%,63.64%和81.28%;经细辛醚处理的粘虫幼虫表现出明显的兴奋、痉挛、麻痹和死亡等症状。【结论】细辛醚对粘虫有较好的熏蒸、触杀作用,对桃蚜、菜青虫具有较强的触杀作用,对玉米象有一定的熏蒸、忌避和种群抑制作用,而对棉铃虫和赤拟谷盗的活性较差,具有明显的杀虫选择性。细辛醚对昆虫的致毒症状与神经毒剂类似。