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In order to study the influence rule of HVDC grounding electrode interference on the cathodic area and anodic area of the pipeline systematically,the Zheneng Jinliwen pipeline was taken as the research object to establish a HVDC interference model using CatPro software based on the real soil structure.The pipe-to-ground current density was calculated under conditions involving different ground polarity,interference current and soil resistivity,and the ranges of the cathodic area and anodic area of the pipeline under such conditions were analyzed.Results showed that after the locations of the grounding electrode and the pipeline were determined,the demarcation point between the cathodic area and anodic area of the pipeline resulting from HVDC interference was fixed and not affected by external conditions.

Objective: To study the risk factors of obstetrical brachial plexus palsy (OBPP)., Methods: Forty-six newborn infants with OBPP were recruited between January 1997 and December 2009 from Technical Appraisement Center for Medical Malpractice of Shandong province as OBPP group. In the control group, 138 newborn infants delivered in the same time, same hospital and same gender were collected, with a ratio of 1:3. All the cases were analyzed retrospectively. The newborn, maternal, childbirth data and working experience of midwives were analyzed by univariate and multivariate logistic regression analysis., Results: (1) External pelvimetries of the two groups were normal. All were singleton newborns by vaginal deliveries with cephalic presentation. Twenty-two newborns had left unilateral palsies, and the other 24 had right unilateral palsies. The numbers of the whole, upper and fore arm type were 17, 26 and 3, respectively. The maternal age, gravidity, parity and gestational weeks were higher in OBPP group than in the control group (P < 0.05). (2) The maternal antepartum body mass index (BMI) [(29.5 ± 2.4) kg/m(2)], height of the uterus [(34.9 ± 2.4) cm] and abdominal circumference [(105 ± 6) cm] in OBPP group were higher than those in the control group [(26.1 ± 2.5) kg/m(2), (33.7 ± 2.2) cm and (99 ± 5) cm, respectively] (P < 0.05). The newborn birth weight in OBPP group [(4390 ± 489) g] was significantly higher than the control group [(3404 ± 360) g] (P < 0.01). The working experience of midwives in OBPP group [(5.2 ± 2.3) years] was less than the control group [(8.9 ± 5.4) years] (P < 0.01). (3) There was a higher proportion of instrumental delivery (28.3% vs. 3.6%), uterine atony (28.3% vs. 6.5%), prolonged second stage (8.7% vs. 0.7%) and fetal malposition (10.9% vs. 2.9%) in the OBPP group than in the control group (P < 0.05). (4) Univariate logistic analysis showed that the P values of maternal age, antepartum BMI, height of uterus, abdominal circumference, newborn birth weight, gravidity, second stage duration, instrumental delivery, fetal malposition, uterine atony and working experience of midwives were all less than 0.10. And the working experience of midwives was a protective factor. (5) The factors listed above were taken as variables, selected stepwise regression for multivariate logistic regression analysis. Boundary value was 0.10. It showed that the antepartum BMI (OR = 1.733) and newborn birth weight (OR = 1.004) were related to OBPP (P < 0.10). The significance of maternal antepartum BMI was higher than birth weight., Conclusions: The maternal antepartum BMI is the most important risk factor for OBPP, and the newborn birth weight is the other risk factor. The working experience of midwives is a protective factor.

Objective: To investigate the feasibility of inducing differentiation of the human amniotic mesenchymal cells (hAMCs) into osteoblasts in vitro, so as to provide the seed cells for bone tissue engineering., Methods: The hAMCs were isolated from abandoned human amnion and cultured in osteogenic media to induce the osteogenic differentiation in vitro. After hAMCs were induced by osteogenic media for 15 days, morphological observation, immunocytochemistry and western blot were used to study the cellular morphology and expression of alkaline phosphatase (ALP), type I collagen, osteopontin and osteocalcin., Results: The primary cultured hAMCs had long spindle shape or irregular shape, which were distributed evenly. The cells were usually suheultured in 5 or 7 days. After subculture, the cells became larger. After cultured by osteogenic media for 15 days, the hAMCs were detected to express ALP, osteocalcin and osteopontin, and secrete type I collagen., Conclusions: The hAMCs are isolated, cultured and amplified easily in vitro. The induced differentiated cells by osteogenic media have typical osteoblast morphological and functional characteristics, which can be used as seed cells for bone tissue engineering.

Objective: To explore the effects of ursodeoxycholic acid (UDCA) on the fluidity of hepatic plasma membrane, glutathione concentration in liver, hepatic estrogen receptors and progesterone receptors in pregnant rats with ethinylestradiol and progesterone induced intrahepatic cholestasis., Methods: sixty clean SD pregnant rats were selected and divided into three groups at random. Since the 13th day of pregnancy after taking blood, normal group was injected subcutaneously with refined vegetable oil 2.5 ml x kg(-1) x d(-1). Control group and treatment group were injected subcutaneously with the solution of progesterone 75 mg x kg(-1) x d(-1) and 17-alpha-ethynylestradio 1.25 mg x kg(-1) x d(-1) till the 17th day. Since the 17th day control group, normal group were fedwish 0.9% natriichloridi solution 5 ml x kg(-1) x d(-1); Treatment group was fedwish UDCA 50 mg x kg(-1) x d(-1) every day. On the 21th day, all rats were killed. Then the livers were collected for study. Membrane fluidity was measured by fluorescence polarization using 1,6-diphenyl-1,3,5-hexatriene (DPH) as a probe. Glutathione concentration was measured by 5,5'-dithionbis (2-nitrobenzoic acid) (DTNB). Estrogen receptors and progesterone receptors were measured by flow cytometry., Results: (1) Hepatic plasma membrane fluidity and glutathione (GSH) concentration: significantly lower level of GSH concentration and higher fluorescence polarization (P) were detected in control group (GSH: 1.13 +/- 0.03, P: 0.149 +/- 0.008) in comparison with normal group (GSH: 2.11 +/- 0.07, P: 0.132 +/- 0.004, P < 0.05). However, Significantly higher level of GSH concentration and lower fluorescence polarization were detected in treatment group (GSH: 1.82 +/- 0.04, P: 0.141 +/- 0.006) in comparison with control group (P < 0.05). The level of GSH concentration and fluorescence polarization were no difference between treatment group and normal group. Hepatic estrogen receptors (ER) and progesterone receptors (PR): The expression of ER and PR in control group (ER: 89.4 +/- 8.4, PR: 112.3 +/- 11.6) were higher than that of other two groups (P < 0.05). The expression of ER and PR in treatment group (ER: 56.4 +/- 7.5, PR: 70.1 +/- 9.3) were lower than that of control group (P < 0.05). But there was no difference between treatment group and normal group (ER: 39.5 +/- 7.3, PR: 59.6 +/- 7.4; P > 0.05)., Conclusion: Ursodeoxycholic acid may be effective drug in treatment intrahepatic cholestasis of pregnancy.