Single-equation models for the tear film in a blink cycle: realistic lid motion.

We consider model problems for the tear film over multiple blink cycles that utilize a single equation for the tear film; the single non-linear partial differential equation that governs the film thickness arises from lubrication theory. The two models that we consider arise from considering the absence of naturally occurring surfactant and the case when the surfactant is strongly affecting the surface tension. The film is considered on a time-varying domain length with specified film thickness and volume flux at each end; only one end of the domain is moving, which is analogous to the upper eyelid moving with each blink. Realistic lid motion from observed blinks is included in the model with end fluxes specified to more closely match the blink cycle than those previously reported. Numerical computations show quantitative agreement with in vivo tear film thickness measurements under partial blink conditions. A transition between periodic and non-periodic solutions has been estimated as a function of closure fraction and this may be a criterion for what is effectively a full blink according to fluid dynamics.     

利宁凝胶联合丙泊酚用于无痛流产术效果观察

目的观察利宁凝胶联合丙泊酚用于无痛流产术中的效果。方法将600例早孕妇女随机分为观察组和对照组各300例,观察组采用利宁凝胶宫颈表面麻醉联合丙泊酚静脉麻醉,对照组仅用丙泊酚静脉麻醉。观察两组宫颈松弛度、肢体或身体扭动、呻吟下腹痛、手术时间、麻醉用药量、出血量。结果观察组宫颈松弛度明显好于对照组,疼痛发生率及平均手术时间、平均出血量明显低于对照组,P<0.05或0.01。结论利宁凝胶联合丙泊酚应用于无痛流产麻醉镇痛效果好,且较为安全,值得临床借鉴。     

冲击载荷作用下蛋白质水溶液润滑吸附膜的生长特性

目的研究蛋白质水溶液挤压润滑条件下材料表面蛋白质吸附膜的动态生长特性及其影响因素。方法利用光干涉技术测量球盘点接触在循环冲击条件下BSA蛋白质水溶液的吸附膜厚的生长过程,并研究冲击载荷、冲击次数、材料表面性质对BSA水溶液的吸附成膜特性的影响。结果动态条件下蛋白质润滑吸附膜要比静态工况下的升高很多,冲击条件下蛋白质吸附膜不断生长,并最终达到稳定厚度。小载荷和疏水材料表面有利于蛋白质润滑吸附膜的生长。钢表面极易形成较厚吸附膜,而陶瓷表面吸附膜厚较低。结论针对冲击载荷作用下蛋白质水溶液润滑吸附膜的生长特性研究对人工关节磨损、松动等的治疗、预防具有一定的临床指导意义。     

Wear Behavior of Fiber Laser Textured TiN Coatings in a Heavy Loaded Sliding Regime

In heavy loaded mating components, such as sliders and sliding bearings, guaranteeing the efficiency of lubricant films for long times during severe service conditions is very complicated. In this work, the benefits deriving from the use of fiber laser sources for surface texturing of very thin TiN coatings in severe wear working conditions were demonstrated. Evaluations of the laser textured dimples shape, geometry and density are given. Wear performance of the fiber laser textured surfaces was evaluated in discontinuous oil lubricated conditions with a flat contact. High normal load and low sliding speed were applied. Comparison tests were also performed on commercial TiN and WC/C coatings. In terms of average wear volume and maximum wear depth, Laser Surface Texturing of TiN provided respectively a 70% and a 45% reduction if compared to plain TiN. If compared to WC/C the wear resistance gains were lower but LST TiN maintained such benefits for longer wear runs. SEM analysis also revealed that the laser interaction provided a localized thermal cracking to the TiN coating. However, the sliding action caused very limited and localized coating fragmentation or delamination.     

The Clitoris—An Appraisal of its Reproductive Function During the Fertile Years: Why Was It,and Still Is,Overlooked in Accounts of Female Sexual Arousal

Stimulating the clitoris activates the brain to instigate changes in the female genital tract, namely, the enhancement of vaginal blood flow that increases vaginal luminal pO₂, vaginal transudate (lubrication) facilitating painless penile penetration and partial neutralization of the basal luminal acidic pH, vaginal tenting, and ballooning delaying sperm transport and allowing semen de-coagulation and capacitation (sperm activation) factors to act until arousal ends (often by orgasm induction). All these genital changes taken together are of major importance in facilitating the possibility of reproductive success (and thus gene propagation) no matter how or when the clitoris is stimulated—they reveal its overlooked reproductive function. Of course, also commensurate with these changes, is its activation of sexual pleasure. The clitoris thus has both procreative (reproductive) and recreative (pleasure) functions of equal importance. Clitoridectomy creates not only sexual disability but also a reproductive disability. Clin. Anat. 32:136–145, 2019. © 2019 Wiley Periodicals, Inc.     

Sexual function in patients with endometriosis: a prospective case–control study in China

ObjectiveEndometriosis is a common disease in women of childbearing age, leading to sexual dysfunction or loss of libido. We aimed to evaluated the effect of endometriosis on women’s sexual function.MethodsWe performed a prospective case–control study to determine the effect of endometriosis on women’s sexual function using a self-administered questionnaire from September 2017 to August 2018. The simplified Chinese version of the Female Sexual Function Index (FSFI) was used to assess sexual function.ResultsWe found that sexual function of women in the endometriosis group (n=77) in all dimensions was significantly lower compared with that in the control group (n=63). The total FSFI score in patients was 25.5, which tended to be lower than that in the control group (26.7). Sexual arousal, sexual pain, and satisfaction were significantly different between the two groups. Sexual arousal and sexual pain scores were significantly lower in the endometriosis group than in the control group at the ages of 31 to 40 years.ConclusionWomen with endometriosis suffer from sexual dysfunction, especially those aged 31 to 40 years. Our findings suggest that the quality of sexual life in this subpopulation needs to be improved.     

Characterization of proteoglycan 4 and hyaluronan composition and lubrication function of ovine synovial fluid following knee surgery

The objective of this study was to determine changes in (1) proteoglycan 4 (PRG4) and hyaluronan (HA) concentration, (2) HA molecular weight (MW) distribution, and (3) cartilage boundary lubricating ability of synovial fluid (SF) from surgical sham (SHAM), anterior cruciate ligament (ACL)/medial collateral ligament (MCL) transection, and lateral meniscectomy (MEN) in a post‐knee surgery ovine model. Ovine SF (oSF) was collected at euthanization 20 weeks after surgery, with the contralateral joint serving as the non‐operative control. PRG4 and HA concentration in oSF was measured by sandwich enzyme‐linked immunosorbent assay, and HA MW distribution by agarose gel electrophoresis. Cartilage boundary lubricating ability of oSF was measured by a cartilage–cartilage friction test. PRG4 and HA concentration in SHAM, ACL/MCL, and MEN oSF were similar in comparison to the contralateral control (CTRL) oSF. The HA MW distribution in the operated oSF for all ranges were similar to the respective CTRL oSF. The kinetic coefficients of friction in operated and CTRL oSF were similar in all groups, and were significantly lower than saline. These results indicate oSF lubricant composition and function at 20 weeks post‐knee surgery were similar to contralateral CTRL, and suggest earlier time points post surgery warrant further investigation. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1549–1554, 2013     

The Impact of the Lubricant Dose on the Reduction of Wear Dies Used in the Forging Process of the Valve Forging

The paper presents the results of research on the influence of the settings of lubrication and cooling system parameters (solenoid valve opening time and lubricant feed pressure in terms of its quantity) in order to select the optimal lubricating conditions and thus reduce the wear of the dies used in the first forging operation of the valve forging made of high-nickel steel. Based on the observation of lubrication in the industrial process, it was found that a significant part of the lubricant fails to reach the die cavity, reaching the outside of it, which causes die wear due to seizure resulting from adhesion of the forging material to the tool surface as well as high lubricant consumption and dirt in the press chamber. The authors proposed their own mobile lubricating and cooling system, which allows for a wide range of adjustments and provided with automatic cleaning procedures of the entire system, unlike the fixed lubrication system used so far in the industrial process. First, tests were carried out in laboratory conditions to determine the highest wettability and the lubricant remaining inside the tool cavity. These tests determined the lubrication system parameter settings that ensured that the greatest amount of lubricant remains in the cold die cavity without the forging process. Then, to verify the obtained results, tests were carried out in the industrial process of hot die forging of valve forgings for short production runs of up to 500 forgings. The results were compared with the measurement of changes in the geometry of tools and forgings based on 3D scanning and surface topography analysis with the use of SEM (Scanning Electron Microscope). For the best results (the variant of the setting of the dose and the time of exposure to lubricant), the forging process was carried out with the use of a new tool up to the maximum service life.     

Biochemical and physiological mechanisms of female genital sexual arousal

Limited studies are available concerning physiological and biochemical mechanisms involved in female sexual function and dysfunction. The paucity of physiological and biochemical data pertaining to genital sexual arousal function is attributed, in part, to lack of reliable experimental models and tools for the investigation of female sexual arousal. This review summarizes research efforts from a number of laboratories in which several experimental models have been established. These include the development of in vivo animal models, organ bath studies, and the establishment of cell cultures. The availability of such experimental model systems have facilitated efforts aimed at defining the neurotransmitters responsible for vaginal smooth muscle relaxation, the role of sex steroid hormones and their receptors in modulating genital hemodynamics, smooth muscle contractility, and neurotransmitter receptor expression. A comprehensive and integral understanding of female sexual function requires detailed investigation of the vascular, neurological (central and peripheral), and structural components of this complex physiological process.     

氨基甲酸钼和钙化合物对脂摩擦性能的影响及其表面膜组成

研究了氨基甲酸钼(MoDTC)和钙化合物在润滑脂中的配伍性。添加MoDTC和钙化合物后,鋰和钙基脂的物理、化学性能仅发生轻微变化。四球机和MM200摩擦机试验表明:MoDTC添加石油磺酸钙或碳酸钙,在减磨和提高承载能力方面有增效作用。利用俄歇和光电子能谱仪,发现表面膜主要由MoS_2,MoO_3,FeS_2,CaCO_3和CaSO_4等组成。正是这种表面膜使得MoDTC和钙化合物具有增效作用。