A Novel Model of Ultrasonic Fatigue Test in Pure Bending

The very high cycle fatigue (VHCF) failure of in-service components is mainly caused by the vibration of thin-wall elements at a high frequency. In this work, a novel model of ultrasonic fatigue test was developed to test thin-wall material in bending up to VHCF with an accelerated frequency. The theoretical principle and finite element analysis were introduced for designing a sample that resonated at the frequency of 20 kHz in flexural vibration. In the advantage of the second-order flexural vibration, the gauge section of the sample was in the pure bending condition which prevented the intricate stress condition for thin-wall material as in the root of cantilever or the contact point of three points bending. Moreover, combining the constraint and the loading contact in one small section significantly reduced heating that originated from the friction at an ultrasonic frequency. Both strain gauge and deflection angle methods were applied to verify the controlling of stress amplitude. The fractography observation on Ti6Al4V samples indicated that the characterized fracture obtained from the novel model was the same as that from the conventional bending test.     

木犀草素促进囊性纤维化跨膜电导调节因子氯离子通道开放

目的：研究木犀草素对依赖于3，5-环腺苷酸（cAMP）的囊性纤维化跨膜电导调节因子（CFTR）Cl^-通道的激活作用。方法：利用稳定共表达人CFTR与一种对卤族元素敏感的荧光绿蛋白突变体（EYFP-H148Q）的Fischer大鼠甲状腺（FRT）细胞模型，测定木犀草素对CFTR介导的I^-内流速度。结果：木犀草素能够以剂量依赖的方式激活CFTR的I^-转运，其对CFTR Cl^-通道的激活效应具有作用迅速、可逆的特点。木犀草素在发挥激活作用时依赖于腺苷环化酶激动剂Forskolin的存在，其单独与细胞孵育不提高细胞内cAMP的水平。结论：发现了木犀草素能够以剂量依赖方式激活CFTR，并且初步确定了木犀草素通过直接与CFTR结合发挥作用。     

Persistent stimulation of lens fiber cell Na,K-ATPase by sodium thiocyanate

The Na,K-ATPase partially purified from porcine lens fiber cells (Sen and Pfeiffer, 1982) is stimulated fourfold (specific activity) by treatment with sodium thiocyanate. The optimum conditions are 1.5 M NaSCN, 2 mg protein ml-1 reaction mixture, pH 7.0, with incubation continued for 30 min at 23 degrees C. Sodium docecyl sulphate-gel electrophoresis and [3H]ouabain binding studies indicate that the extent of purity is not increased significantly by the procedure. The high-activity preparation has elevated phospholipid:protein and phosphatidylethanolamine:sphingomyelin ratios compared with the deoxycholate-extracted starting material. The cholesterol:phospholipid ratio and phospholipid acyl group composition are not significantly altered by SCN- treatment. Measurements of 1,6-diphenyl-1,3,5-hexatriene fluorescence polarization show that SNC- treatment produces approximately a 5 degrees C decrease in a membrane phase transition temperature. The phase transition also affects the activation energy of the Na,K-ATPase reaction and probably reflects the onset of the gel to liquid crystalline transition rather than the midpoint location of the transition per se. p-Nitrophenylphosphatase activity and Na,K-ATPase activity in the gel state membrane are also increased by SCN- treatment. Increased specific activity may result, in part, from a membrane fluidity-dependent enzyme activation but is also due, in part, to the expression of latent enzyme activity. Using ouabain-binding data and the specific activity of the activated preparation, it can be shown that the turnover number of the fiber cell enzyme is approximately 1% of that observed in most other tissues.     

Efficacy of vaginal misoprostol before hysteroscopy for cervical priming in patients who have undergone cesarean section and no vaginal deliveries

We wanted to investigate the effect of misoprostol administered vaginally before operative hysteroscopy on cervical dilation, complications, and failure rates in patients who have undergone cesarean section and who have never delivered vaginally. Sixty patients who had undergone cesarean section, who had never delivered vaginally before, and were about to undergo hysteroscopy for various intrauterine lesions were included in this randomized controlled study. Thirty-two patients in the study group were given misoprostol 400 microg, and 28 patients in the control group were given placebo (hexetidine pill) vaginally twice, 6 and 12 hours before the procedure. Primary endpoints were cervical width detected with Hegar dilators and complication and failure rates. Mean cervical width was greater in patients in the study group (6.5 +/- 0.8) than it was in patients in the control group (3.0 +/- 0.6), (p = .0001). Complication and failure rates were lower in patients in the study group (p = .01). Administration of vaginal misoprostol before hysteroscopy proved to be effective in cervical ripening and in reducing complication and failure rates.     

Effect of honey on intestinal morphology, intraabdominal adhesions and anastomotic healing

In the present study, attempts have been made to determine the effects of honey on intestinal morphology, postoperative adhesions, and the healing of colonic anastomoses in the rats after colonic resection and anastomosis. Thirty-six rats were randomly divided into three groups each including 12 animals. Colonic resection and anastomosis were performed on all animals. Rats were fed with standard rat chow in group I, standard rat chow plus 10 g/kg/day honey in group II and artificial honey including the same caloric amount with honey in group III. Adhesion scores, bursting pressures and histopathological examinations were evaluated. Colonic bursting pressures of honey group were significantly better than control and artificial honey groups. Histological analysis of anastomotic site showed that submucosa and muscularis propria were nearly filled with granulation tissue and regular fibrin matrix in honey group. There was statistically significant difference between the adhesion scores of honey vs artificial honey and control groups. The scores of histological changes of ileum in honey group were significantly different from other groups. These results indicate a protective role of honey against intraabdominal adhesions and anastomotic dehiscence.     

Oral contraceptive pretreatment does not improve outcome in microdose gonadotrophin-releasing hormone agonist protocol among poor responder intracytoplasmic sperm injection patients

Purpose To compare oral contraceptive (OC) pretreatment plus microdose GnRH-a in flare-up protocol and non-OC microdose GnRH-a in flare-up protocol among poor responder ICSI patients. Methods A retrospective analysis of poor responder ICSI patients. Patients were divided into two groups according to used microdose protocol. Precycle treatment with OC followed by follicular phase administration of 40 μg sc leuprolide acetate (LA) every 12 h beginning on after 2 day pill-free period and rFSH administration was begun on the third day of LA administration (OC-Group, n = 26). Alternatively on day 2 after menses, patients were administered similar stimulation regime (non-OC Group, n = 27). Results There were no significant differences between groups in the number of oocytes, peak estradiol levels, endometrial thickness, fertilization rates and embryo quality. Implantations and pregnancy rates per embryo transfer were similar. Conclusion OC pretreatment plus microdose GnRHa in flare-up protocol does not offer advantages over non-OC microdose GnRHa in flare-up protocol among poor responder ICSI patients. Capsule Oral contraceptive pretreatment plus microdose GnRH-a in flare-up protocol does not offer advantages over non-OC microdose GnRH-a in flare-up protocol among poor responder ICSI patients.     

Effect of test order on sensitivity in vulvodynia

OBJECTIVE: To assess the effect of order of sensitivity testing at the vulva and thumb on the sensitivity determined at the second site tested among women with and without vulvodynia. STUDY DESIGN: We evaluated the stability of sensitivity measurements to pressure at the vulva and thumb when the order of testing was randomized to vulva first vs. thumb first; we repeated testing 1 week later in the opposite order. RESULTS: Stability of results over time and the influence of the order of testing were determined among 13 women with vulvodynia and 20 asymptomatic control women. We found a strong correlation between results compared between the first and second visits as well as no order effect. CONCLUSION: The order of testing at vulvar and peripheral sites has little impact on the results of pressure-responsive sensitivity testing among women with and without vulvodynia.     

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