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.

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.

The Role of Eye Contact in a Classroom Setting—From an Intercultural Perspective

The field of education is increasingly catching people’s eyes as more and more people become aware of its influence and significance on the young generation.Nevertheless,when it comes to the teaching and learning process,the role of nonverbal behavior is often neglected.Indeed,nonverbal behavior constitutes more than 90%of our daily communication,and it is also one vi⁃tal aspect in a classroom setting,which has the power of maintaining classroom order and the teacher-student relationships.Eye contact,one crucial part of nonverbal behavior,is a topic worth researching.The research focuses on the controversial topic that is based on a contrastive analysis of how eye contact functions differently in the western and non-western cultures.Theories of both western and non-western scholars are presented to rationalize why the use of direct and constant eye contact in a classroom context differs in the two cultures.More theories and practices are also cited to explain an apparent inconsistency,which is“teachers in both western and non-western cultures are encouraged to use direct and constant eye contacts in classes,while people in Asian countries tend to avoid direct eye contact”.

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.

虚拟-现实手术模拟系统在眼科住院医师微创白内障手术培训中的应用效果

目的:探讨虚拟-现实手术操作训练在眼科住院医师微创白内障手术技能培训中的应用及效果。方法:前瞻性对照研究。选取2019/2021年在南京医科大学附属眼科医院已完成3a住院医师规范化培训的20名年资相同的眼科住院医师为研究对象,通过理论考核后随机分为虚拟-现实手术操作训练(Dry-lab)组和实体动物手术操作训练(Wet-lab)组,每组各10名。Dry-lab组和Wet-lab组医师分别使用Eye SI虚拟手术模拟器和猪眼进行训练。训练结束后使用Eye SI虚拟手术模拟器和实体猪眼操作对两组住院医师的总体培训效果进行评分,使用虚拟手术模拟器对两组住院医师的模块培训效果进行评分,并采用问卷调查对两种培训方式进行客观评价。结果:Dry-lab组医师两项操作考核总评分、模拟器考核评分、实体猪眼操作考核评分均显著高于Wet-lab组(88.03±1.34分vs 80.35±2.87分,87.50±3.03分vs 77.60±5.62分,88.57±1.89分vs 83.10±3.22分,均P<0.01)。模拟器模块考核结果显示,Dry-lab组医师各模块考核评分及用时均显著优于Wet-lab组(P<0.01)。问卷调查结果显示,在培训新颖性、是否贴近真实手术体验、对显微手术技能提高的帮助程度、经过该培训是否有信心进行真实手术及手术培训的整体满意度方面,Dry-lab组医师对于培训方式的效果评价均优于Wet-lab组(P<0.05)。结论:将虚拟-现实手术操作训练应用于眼科住院医师白内障手术技能培训可以显著提升住院医师的白内障显微手术操作技能,提高培训整体满意度,帮助住院医师在执业初期提升真实手术时的信心、心理素质、决策及处理能力,为建立眼科住院医师正式、规范化的白内障手术培训体系提供了新的标准和模式。

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.

Crosslinked hyaluronic acid with liposomes and crocin for management symptoms of dry eye disease caused by moderate meibomian gland dysfunction

AIM:To study the effect of uncrosslinked and crosslinked hyaluronic acid combined with other artificial tear components in patients with dry eye caused by moderate meibomian gland dysfunction.METHODS:Prospective,single-blind,contralateral eye study.Fifty eyes(25 patients)were analyzed.Eye selection for each tear type was random,and the eye drop formulations,0.4%uncrosslinked hyaluronic acid and 0.2%galactoxyloglucan(tear A)and 0.15%crosslinked hyaluronic acid,crocin,and liposomes(tear B)were used.The determined dosing schedule was three times a day for six weeks,and the study participants underwent a clinical examination before and 45 d after lubricant treatment.The Schirmer test,tear breakup time(TBUT)test,and Ocular Surface Disease Index(OSDI)questionnaire were applied before and after instillation period with both types of artificial tears.RESULTS:On the Schirmer test,a significant improvement was obtained with both tear A(P<0.01)and tear B(P<0.01).On the TBUT test,a significant improvement was obtained with tear A(P<0.01)and tear B(P<0.01).The OSDI score significantly decreased after instillation period with both artificial tear types(P<0.01).CONCLUSION:Uncrosslinked hyaluronic acid combined with other components,such as tamarind seed polysaccharide,and crosslinked hyaluronic acid combined with liposomes and crocin are effective for management symptoms of dry eye disease.

Comparison of the effects of first and second generation silicone hydrogel contact lens wear on tear film osmolarity

AIM:To compare the effects of first and second generation silicone hydrogel(SiH) contact lens wear on tear film osmolarity.METHODS:The healthy subjects who have never used contact lenses before were enrolled in the study.Tear film osmolarity values of 16 eyes(group 1) who wore first generation SiH contact lenses were compared with those of 18 eyes(group 2) who wore second generation SiH contact lenses after three months follow-up.RESULTS:Beforecontactlenswear,tearfilmosmolarity of groups 1 and 2 were 305.02±49.08 milliosmole(mOsm) and 284.66±30.18mOsm,respectively.After three months of contact lens wear,osmolarity values were found 317.74±60.23mOsm in group 1 and 298.40±37.77mOsm in group 2.Although osmolarity values for both groups of SiH contact lens wear after three months periods were slightly higher than before the contact lens wear,the difference was not statistically significant. CONCLUSION:Contact lens wear may cause evaporation from the tear film and can increase tear film osmolarity leading to symptoms of dry eye disease.In the current study,there is a tendency to increase tear film osmolarity for both groups of SiH contact lens wear,but the difference is not statistically significant.

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.

EYA4通过抑制NF-κB依赖的RAP1反式激活抑制肝细胞癌的生长和侵袭

背景与目的我们之前研究表明,眼缺失蛋白同源物4(eyes absent homolog 4,EYA4)是果蝇眼部发育相关的眼缺乏蛋白家族成员之一,在肝细胞癌(hepatocellular carcinoma,HCC)标本中常发生甲基化和沉默,并与患者生存期短密切相关。本研究旨在探讨EYA4在HCC中作为肿瘤抑制因子的作用机制。方法转染EYA4表达质粒(pEYA4)构建稳定表达EYA4的人HCC细胞系Huh-7和PLC/PRF/5(PLC)。通过BALB/c裸鼠皮下注射稳定转染细胞建立异种移植肿瘤。组织标本来自75例病理诊断为HCC的患者。采用实时定量聚合酶链式反应(real-time polymerase chain reaction,real-time PCR)、蛋白质免疫印迹和免疫组织化学的方法检测EYA4在细胞系、异种移植物和临床标本中的表达;研究了稳定转染细胞系的细胞增殖、克隆形成、侵袭性和肿瘤形成。利用基因表达芯片筛选EYA4调节的基因。通过共转染EYA4和带Flag标签的RAS相关蛋白1A(RAS-related protein 1A,RAP1A)基因的表达质粒(pEYA4和Flag-RAP1A)、功能研究、染色质免疫共沉淀、免疫荧光染色和细胞泛素化分析等方法,研究了EYA4对核因子-κB(nuclear factor-κB,NF-κB)/RAS相关蛋白1(RAS-related protein 1,RAP1)信号通路的影响。结果恢复HCC细胞系中EYA4的表达可抑制细胞的增殖、抑制克隆形成、降低细胞的侵袭性和抑制异种移植肿瘤生长,在体外实验中Flag-RAP1A可逆转pEYA4的抑制作用。用肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)激活NF-κB通路可增加p65与RAP1A基因启动子的结合并上调RAP1蛋白的表达。用BAY 11-7085和p65 siRNA抑制NF-κB通路,成功阻断了TNF-α诱导的RAP1上调。EYA4拮抗了TNF-α诱导的NF-κB抑制因子α(inhibitor of NF-κBα,IκBα)的磷酸化和泛素化以及p65的核易位和反式激活,进而抑制了NF-κB的活性和RAP1的表达。用calyculin A阻断EYA4的丝氨酸/苏氨酸磷酸酶活性可显著消除其对NF-κB活性的抑制作用。此外,EYA4的表达与HCC临床标本中IκBα/RAP1活性呈负相关。结论我们的研究结果为明确EYA4是真正的肿瘤抑制因子提供了功能和机制的理论基础,该肿瘤抑制因子可抑制NF-κB/RAP1信号通路的异常激活,从而抑制HCC生长和侵袭。

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.

Hydrogel-based contact lens achieve prolonged,local drug delivery to the eye

With the support by the National Natural Science Foundation of China,the research group led by Prof.Jiang Gangbiao(蒋刚彪)at the Department of Pharmaceutical Engineering,College of Materials and Energy,South China Agricultural University,in collaboration with the research group led by Prof.Yuan

Ocular drug delivery systems:An overview

The major challenge faced by today's pharmacologist and formulation scientist is ocular drug delivery. Topical eye drop is the most convenient and patient compliant route of drug administration,especially for the treatment of anterior segment diseases. Delivery of drugs to the targeted ocular tissues is restricted by various precorneal,dynamic and static ocular barriers. Also,therapeutic drug levels are not maintained for longer duration in target tissues. In the past two decades,ocular drug delivery research acceleratedly advanced towards developing a novel,safe and patient compliant formulation and drug delivery devices/techniques,which may surpass these barriers and maintain drug levels in tissues. Anterior segment drug delivery advances are witnessed by modulation of conventional topical solutions with permeation and viscosity enhancers. Also,it includes development of conventional topical formulations such as suspensions,emulsions and ointments. Various nanoformulations have also been introduced for anterior segment ocular drug delivery. On the other hand,for posterior ocular delivery,research has been immensely focused towards development of drug releasing devices and nanoformulations for treating chronic vitreo-retinal diseases. These novel devices and/or formulations may help to surpass ocular barriers and associated side effects with conventional topicaldrops. Also,these novel devices and/or formulations are easy to formulate,no/negligibly irritating,possess high precorneal residence time,sustain the drug release,and enhance ocular bioavailability of therapeutics. An update of current research advancement in ocular drug delivery necessitates and helps drug delivery scientists to modulate their think process and develop novel and safe drug delivery strategies. Current review intends to summarize the existing conventional formulations for ocular delivery and their advancements followed by current nanotechnology based formulation developments. Also,recent developments with other ocular drug delivery strategies employing in situ gels,implants,contact lens and microneedles have been discussed.

Novel application of PEG/SDS interaction as a wettability modifier of hydrophobic carbonate surfaces

Wettability alteration of carbonate reservoirs from oil-wet to water-wet is an important method to increase the efficiency of oil recovery. Interaction between surfactants and polymers can enhance the effectiveness of surfactants in EOR applications. In this study, the interaction of polyethylene glycol(PEG) with an ionic surfactant, sodium dodecyl sulphate(SDS),is evaluated on an oil-wet carbonate rock surface by using contact angle measurements. The results reveal that wettability alteration of carbonate rocks is achieved through PEG/SDS interaction on the rock surface above a critical aggregation concentration(CAC). The behaviour of PEG/SDS aqueous solutions is evaluated using surface and interfacial tension measurements. Furthermore, the effect of PEG and SDS concentrations and impact of electrolyte addition on PEG/SDS interaction are investigated. It is shown that electrolyte(NaCl) can effectively decrease the CAC values and accordingly initiate the wettability alteration of rocks. Moreover, in a constant SDS concentration, the addition of NaCl leads to a reduction in the contact angle, which can also be obtained by increasing the aging time, temperature and pre-adsorption of PEG on the rock surface.

Effect of Various Carbides on the Wettability in Ni/Ti(C,N) System

The wettability in Ni / Ti （ C, N ） systems with various carbides additions was investigated by the sessile drop technique. The substrates prepared by HP at 2073 K for 1 h before and after wetting were characterized by XRD . The microstructure ca metall ceramics interfaces was observed via SEM in a back scattered mode. Furthermore , an X-ray energy-dispersive spectrometer （ EDS ） attached to SEM was used to study the element diffusion in interfacial regions. The resalts reveal that reactive wetting takes place in the system in high tempercature wetting procedure , which is controlled by diffusion and dissolution mechanism. Results also show that the contact angles decrease with various carbides additions, iuelnding WC , Mo2 C, TaC , NbC and VC , and decrease continuously with the increasing of additions. The order of the contact angles in Ni/Ti （ C, N ） systems with 10 wt% carbides acMitions is Mo2 C 〈 TaC 〈 WC 〈 VC 〈 NbC. The enhancement of the wettability is due to an alloying procedure during high temperature wetting when metallic atoms diffuse into Ni phase, which decreases the interfacial energy of Ni/ Ti （ C, N） systems.

Robust transport of charge carriers in in-plane 1T′-2H MoTe_(2) homojunctions with ohmic contact

Metal-semiconductor ohmic contacts are required to reduce the energy dissipation for two-dimensional (2D) electronic devices, and phase engineering of 2D transition-metal dichalcogenides (TMDCs) is a promising approach for building ohmic contacts. Here, 2D in-plane 1T′-2H MoTe2 homojunctions were prepared by direct epitaxy via vapor deposition. The interface properties of in-plane 1T′-2H MoTe2 homojunction were investigated in detail by combining experiments, calculations and theories. The ohmic contact properties of 1T′-2H MoTe2 homojunction were proved according to Kelvin force probe microscopy and density functional theory calculations. The charge carriers robust transport in in-plane 1T′-2H MoTe2 homojunction without Fermi-level pinning can be well described by Poisson equation and band alignment. These results indicate that phase engineering of 2D TMDCs is promising to construct ohmic contacts for device applications.

Does the Type of Dive Mask Matter to a Shark?

Eye contact with a shark is a crucial element during an interaction with a diver. Different mask frames change the size of a diver’s available field of vision, and so make a person’s eyes unequally visible from different angles, particularly when comparing mirrored to regular glass. This study examined whether it matters to a shark if it can see a diver’s eyes when getting closer. The test-subjects changed masks in a random, timed routine, while the relative distance, the absolute distance between a shark and diver expressed in a fraction of the shark’s body length, between approaching shark and human was tallied. Sharks came significantly closer (p = 0.0139) when a diver’s eyes could not be detected, showing that they orient themselves and approach based on the human’s eyes. Given that human comprehension of sharks is rudimentary, every possible benefit, even a minimal one like choosing the most optimal mask, is recommended whenever approaching sharks are likely to be encountered.

Mechanism on Moho offset induced by aseismic slip of deeply buried faults

Recent high-resolution deep seismic reflection profile across the Kunlun fault in northeastern Tibet shows clearly that the Moho is cut off by a complex thrust fault system. Moho offset is a general phenomenon, but little is known about the dynamic mechanism. In this study, contact models with Maxwell materials are used to simulate the mechanical process of Moho offset induced by the aseismic slip of deeply buried faults. Based on the seismic reflection data, we project a single fault model and a complex fault system model with two faults inter- secting. The deformations of the Moho, the aseismic slips, and contact stresses on faults in different models are discussed in detail. Results show that the Moho offset might be produced by aseismic slip of deeply buried faults, and the magnitude is influenced by the friction coefficient of faults and the viscosity of the lower crust. The maximum slip occurs near the Moho on the single fault or at the crossing point of two intersecting faults system. Stress concentrates mainly on the Moho, the deep end of faults, or the crossing point. This study will throw light on understanding the mechanism of Moho offset and aseismic slip of deeply buried faults. The results of complex fault system with two faults intersecting are also useful to understand the shallow intersecting faults that may cause earthquakes.

Changes in Breastfeeding and of Breasts before and after Babies’ Surgeries for Ankyloglossia with Deviation of the Epiglottis and Larynx (ADEL) —Healthy Breastfeedin

Background: Historically frenotomy was performed at newborn babies’ baptism for healthy breast-feeding over many centuries. Although it was necessary for nursing babies, its application was denied subjectively without clinical observation since the early 20th century. As a result solutions for breastfeeding and breast problems are confused now. Methods: We studied changes in breastfeeding and mothers’ breasts before and one month after the surgeries for ADEL by standards for healthy breastfeeding and breasts. Results: With regard to suckling, before the surgeries 24% of babies opened their eyes during breastfeeding, while after surgeries 76% opened eyes while nursing. 30% of the babies latched onto the mother’s breast with a wide-open mouth. After surgeries, 84% properly latched on. 73% of the babies had calluses on the upper lip before surgeries, and no calluses were observed after surgeries. 27% of babies before surgeries moved the jaws during breast-feeding, but after surgeries 88% moved the jaws while nursing. White debris was on the dorsum tongue in 70% of babies prior to surgeries. After surgeries, 22% were with debris. 67% of mothers experienced nipple pain before their babies’ surgeries while 6% had pain after the surgeries. Flattened nipples were observed in 55% of mothers before the infants’ surgeries, 7% after surgeries. 23% of mothers had breast pain before the surgeries, and 4% had breast pain after the surgeries. Mastitis was also reduced from 9% to 1% after surgeries. 73% of women had palpable breast masses, and after the surgeries 25% had palpable masses. Summary: Remarkable improvements in breastfeeding and in women’s breasts were achieved after their infants underwent operations for ADEL. These results indicate the necessity of surgical interventions in babies with ADEL for healthy breastfeeding and breasts (279).

Optically Powered Temperature Measuring Instrument for Big Rotor

Abstract: A micro - power consumption non - contact temperature measuring instrument for big rotor is introduced. As it solves very well the signal coupling under high speed rotation and power supply problem for probe, the instrument can realize persistent on - line temperature measurement for big rotor drived by the ordinary light transmitted by optical fiber under the room light.