Objective To provide evidence for more accurate diagnosis of birth defects based on the pathoauatomy of congenital malformations. Methods Data used in this study were obtained fi＇om Luliang City Hospital and three co...Objective To provide evidence for more accurate diagnosis of birth defects based on the pathoauatomy of congenital malformations. Methods Data used in this study were obtained fi＇om Luliang City Hospital and three county hospitals of Shanxi province between February 2004 and March 2006. Autopsy and pathological examination of 160 dead fetuses and stillbirths were performed. Photos of dead fetuses and stillbirths were taken, tissues were cut into sections for pathological examination under microscope, all pathological information was recorded, and percentage of birth defects was calculated. Results The proportion of dead fetuses and stillbirths with or without congenital malformations was 84.4% （135/160） and 15.6% （25/160）, respectively. There were 16 categories of major external and internal birth defects in 135 cases of such defects. Congenital heart defects, anencephaly and spina bifida had a higher prevalence rate in the study period. The prevalence rate of non-malformation death and birth defects 〈 28 gestational weeks and internal anomalies ≥ 28 gestational weeks was 14.61% （61/4175） and 17.25% （72/4175）, respectively. A total of 413 in situ anomalies were found in 135 cases of autopsy. Spina bifida, anencephaly, congenital heart defects, aplasia or accessory lobe of lung, renal agenesis and dysplasis and congenital hydrocephaly were more closely associated with severe malformations than with mitis malformations. The cases of dead fetuses and stillbirths with multiple malformations （/〉 2 in situ anomalies） had a higher proportion （74.1%）, whereas those with isolated malformations had a lower proportion （25.93%）. Conclusion The occurrence of congenital malformations in different embryonic developmental stages affects multiple organs. Postmortem examination of internal and multiple malformations of fetal deaths and stillbirths can provide more accurate diagnostic information for birth defects.展开更多
Efficient detection of coalbed methane(CBM) co-production interference is the key to timely adjusting the development plan and improving the co-production efficiency. Based on production data of six typical CBM co-pro...Efficient detection of coalbed methane(CBM) co-production interference is the key to timely adjusting the development plan and improving the co-production efficiency. Based on production data of six typical CBM co-production wells in the Zhijin block of western Guizhou Province, China, the production characteristic curves, including production indication curve, curve of daily water production per unit drawdown of producing fluid level with time, and curve of water production per unit differential pressure with time have been analyzed to explore the response characteristics of co-production interference on the production characteristic curves. Based on the unit water inflow data of pumping test in coal measures, the critical value of in-situ water production of the CBM wells is 2 m^(3)/(d·m). The form and the slope of the initial linear section of the production indication curves have clear responses to the interference, which can be used to discriminate internal water source from external water source based on the critical slope value of 200 m^(3)/MPa in the initial linear section of the production indication curve. The time variation curves of water production per unit differential pressure can be divided into two morphological types: up-concave curve and down-concave curve. The former is represented by producing internal water with average daily gas production greater than 800 m^(3)/d, and the latter produces external water with average daily gas production smaller than 400 m^(3)/d. The method and critical indexes for recognition of CBM co-production interference based on the production characteristic curve are constructed. A template for discriminating interference of CBM co-production was constructed combined with the gas production efficiency analysis, which can provide reference for optimizing co-production engineering design and exploring economic and efficient co-production mode.展开更多
基金funded by National"973"project on Population and Health(No.2007CB511901)China Postdoctoral Science Fundation Funded Project(No.200801016)+2 种基金National Health Baby Promotion Program(No.FP2000NO13)Education Ministry Key Program(No.02185)National Yang Zi Scholar Program,211 and 985 projects of Peking University(No.20020903)
文摘Objective To provide evidence for more accurate diagnosis of birth defects based on the pathoauatomy of congenital malformations. Methods Data used in this study were obtained fi＇om Luliang City Hospital and three county hospitals of Shanxi province between February 2004 and March 2006. Autopsy and pathological examination of 160 dead fetuses and stillbirths were performed. Photos of dead fetuses and stillbirths were taken, tissues were cut into sections for pathological examination under microscope, all pathological information was recorded, and percentage of birth defects was calculated. Results The proportion of dead fetuses and stillbirths with or without congenital malformations was 84.4% （135/160） and 15.6% （25/160）, respectively. There were 16 categories of major external and internal birth defects in 135 cases of such defects. Congenital heart defects, anencephaly and spina bifida had a higher prevalence rate in the study period. The prevalence rate of non-malformation death and birth defects 〈 28 gestational weeks and internal anomalies ≥ 28 gestational weeks was 14.61% （61/4175） and 17.25% （72/4175）, respectively. A total of 413 in situ anomalies were found in 135 cases of autopsy. Spina bifida, anencephaly, congenital heart defects, aplasia or accessory lobe of lung, renal agenesis and dysplasis and congenital hydrocephaly were more closely associated with severe malformations than with mitis malformations. The cases of dead fetuses and stillbirths with multiple malformations （/〉 2 in situ anomalies） had a higher proportion （74.1%）, whereas those with isolated malformations had a lower proportion （25.93%）. Conclusion The occurrence of congenital malformations in different embryonic developmental stages affects multiple organs. Postmortem examination of internal and multiple malformations of fetal deaths and stillbirths can provide more accurate diagnostic information for birth defects.
基金National Natural Science Foundation of China(42002195)National Science and Technology Major Project(2016ZX05044)National Natural Science Foundation of China(42130802)。
文摘Efficient detection of coalbed methane(CBM) co-production interference is the key to timely adjusting the development plan and improving the co-production efficiency. Based on production data of six typical CBM co-production wells in the Zhijin block of western Guizhou Province, China, the production characteristic curves, including production indication curve, curve of daily water production per unit drawdown of producing fluid level with time, and curve of water production per unit differential pressure with time have been analyzed to explore the response characteristics of co-production interference on the production characteristic curves. Based on the unit water inflow data of pumping test in coal measures, the critical value of in-situ water production of the CBM wells is 2 m^(3)/(d·m). The form and the slope of the initial linear section of the production indication curves have clear responses to the interference, which can be used to discriminate internal water source from external water source based on the critical slope value of 200 m^(3)/MPa in the initial linear section of the production indication curve. The time variation curves of water production per unit differential pressure can be divided into two morphological types: up-concave curve and down-concave curve. The former is represented by producing internal water with average daily gas production greater than 800 m^(3)/d, and the latter produces external water with average daily gas production smaller than 400 m^(3)/d. The method and critical indexes for recognition of CBM co-production interference based on the production characteristic curve are constructed. A template for discriminating interference of CBM co-production was constructed combined with the gas production efficiency analysis, which can provide reference for optimizing co-production engineering design and exploring economic and efficient co-production mode.
