Vertical profiles of chl-a and primary productivity in the middle continental shelf area and eddy area of the East China Sea were studied using data from a cruise in the East China Sea in February to March, 1997 and a...Vertical profiles of chl-a and primary productivity in the middle continental shelf area and eddy area of the East China Sea were studied using data from a cruise in the East China Sea in February to March, 1997 and a cruise in July, 1998. The results showed that chl-a vertical distribution closely related to in situ hydrological and nutrient conditions. Chla-a concentration ranged from 0.22 to 0.35 mg/m 3 and 0.93-1.09 mg/m 3 in the eddy area and in the middle continental shelf area, respectively. In both areas, chl-a concentrations in deep layers were slightly higher than those in shallow layers, but was of the same order of magnitude. In summer, when a thermocline existed in the water column, highest chl-a concentrations appeared at the base of the thermocline layers in both areas. In the eddy area, chl-a concentration maximized at 3l.743 mg/m 3, and averaged l.143 mg/m 3 below 30 m depth. In the middle continental shelf area, the highest chl-a concentration was 2.120 mg/m 3, the average was 1.168 mg/m 3. The primary productivity reached 1418.76 mgC/(m 2·d) in summer and 1360.69 mgC/(m 2·d) in winter. In the eddy area, the primary productivity was 787.50 mgC/(m 2·d) in summer and 159.04 mgC/(m 2·d) in winter. Vertical carbon sinking rate from the deep layer to the bottom in both areas is also discussed in this paper.展开更多
Objective To evaluate the effect of elective repeat cesarean section on the maternal and neonatal outcomes. Methods A retrospective clinic- and hospital-based survey was designed for comparing the maternal and neonat...Objective To evaluate the effect of elective repeat cesarean section on the maternal and neonatal outcomes. Methods A retrospective clinic- and hospital-based survey was designed for comparing the maternal and neonatal outcomes of elective repeat cesarean section [RCS group （one previous cesarean section） and MRCS group （two or more previous cesarean sections）] and primary cesarean section （FCS group） at Peking Union Medical College Hospital from January 1998 to December 2007. Results The incidence of repeat cesarean section increased from 1.26% to 7.32%. The mean gestational age at delivery in RCS group （38.1±1.8 weeks） and MRCS group （37.3±2.5 weeks） were significantly shorter than that in FCS group （38.9±2.1 weeks, all P〈0.01）. The incidence of complication was 33.8% and 33.3% in RCS group and MRCS group respectively, and was significantly higher than that in FCS group （7.9%, P〈0.05）. Dense adhesion （13.5% vs. 0.4%, OR=7.156, 95% CI： 1.7-30.7, P〈0.01） and uterine rupture （1.0% vs. O,P〈0.05） were commoner in RCS group compared with FCS group. Neonatal morbidity was similar among three groups （P〉0.05）. Conclusions Repeat cesarean section is associated with more complicated surgery technique and increased frequency of maternal morbidity. However, the incidence of neonatal morbidity is similar to primary cesarean section.展开更多
The large reserves ofoil are disposed in zones of permafrost in shelf and continental fields. In Europe the subarctic and arctic tundra are abundant only in Nenetsky autonomous area and in the north-east of the republ...The large reserves ofoil are disposed in zones of permafrost in shelf and continental fields. In Europe the subarctic and arctic tundra are abundant only in Nenetsky autonomous area and in the north-east of the republic of Komi. Oil and gas production activity has threatened richest biological resources and health of the population of the region. A singularity of petroliferous fields of the north of Russia is the existence of the thick strata of permafrost. On top of them different heat-insulating overlying layers （snow, biogenic covers） reside. State and dynamics of permafrost cause progressing dangerous exogenic geoecological processes, which are exhibited completely. State of permafrost is instituted by exchange of heat in near-surface strata of a geological section. During the development of oil fields there is a disturbance of a temperature schedule of permafrost. For estimation of technical attack the analytical computational method of influence of the different factors on value of annual heat exchange and prediction of geocryological conditions is proposed. It is shown, that such dangerous phenomena as degradation of permafrost and thermokarst would develop in the first place, which would cause the destruction of natural ecosystems.展开更多
文摘Vertical profiles of chl-a and primary productivity in the middle continental shelf area and eddy area of the East China Sea were studied using data from a cruise in the East China Sea in February to March, 1997 and a cruise in July, 1998. The results showed that chl-a vertical distribution closely related to in situ hydrological and nutrient conditions. Chla-a concentration ranged from 0.22 to 0.35 mg/m 3 and 0.93-1.09 mg/m 3 in the eddy area and in the middle continental shelf area, respectively. In both areas, chl-a concentrations in deep layers were slightly higher than those in shallow layers, but was of the same order of magnitude. In summer, when a thermocline existed in the water column, highest chl-a concentrations appeared at the base of the thermocline layers in both areas. In the eddy area, chl-a concentration maximized at 3l.743 mg/m 3, and averaged l.143 mg/m 3 below 30 m depth. In the middle continental shelf area, the highest chl-a concentration was 2.120 mg/m 3, the average was 1.168 mg/m 3. The primary productivity reached 1418.76 mgC/(m 2·d) in summer and 1360.69 mgC/(m 2·d) in winter. In the eddy area, the primary productivity was 787.50 mgC/(m 2·d) in summer and 159.04 mgC/(m 2·d) in winter. Vertical carbon sinking rate from the deep layer to the bottom in both areas is also discussed in this paper.
文摘Objective To evaluate the effect of elective repeat cesarean section on the maternal and neonatal outcomes. Methods A retrospective clinic- and hospital-based survey was designed for comparing the maternal and neonatal outcomes of elective repeat cesarean section [RCS group （one previous cesarean section） and MRCS group （two or more previous cesarean sections）] and primary cesarean section （FCS group） at Peking Union Medical College Hospital from January 1998 to December 2007. Results The incidence of repeat cesarean section increased from 1.26% to 7.32%. The mean gestational age at delivery in RCS group （38.1±1.8 weeks） and MRCS group （37.3±2.5 weeks） were significantly shorter than that in FCS group （38.9±2.1 weeks, all P〈0.01）. The incidence of complication was 33.8% and 33.3% in RCS group and MRCS group respectively, and was significantly higher than that in FCS group （7.9%, P〈0.05）. Dense adhesion （13.5% vs. 0.4%, OR=7.156, 95% CI： 1.7-30.7, P〈0.01） and uterine rupture （1.0% vs. O,P〈0.05） were commoner in RCS group compared with FCS group. Neonatal morbidity was similar among three groups （P〉0.05）. Conclusions Repeat cesarean section is associated with more complicated surgery technique and increased frequency of maternal morbidity. However, the incidence of neonatal morbidity is similar to primary cesarean section.
文摘The large reserves ofoil are disposed in zones of permafrost in shelf and continental fields. In Europe the subarctic and arctic tundra are abundant only in Nenetsky autonomous area and in the north-east of the republic of Komi. Oil and gas production activity has threatened richest biological resources and health of the population of the region. A singularity of petroliferous fields of the north of Russia is the existence of the thick strata of permafrost. On top of them different heat-insulating overlying layers （snow, biogenic covers） reside. State and dynamics of permafrost cause progressing dangerous exogenic geoecological processes, which are exhibited completely. State of permafrost is instituted by exchange of heat in near-surface strata of a geological section. During the development of oil fields there is a disturbance of a temperature schedule of permafrost. For estimation of technical attack the analytical computational method of influence of the different factors on value of annual heat exchange and prediction of geocryological conditions is proposed. It is shown, that such dangerous phenomena as degradation of permafrost and thermokarst would develop in the first place, which would cause the destruction of natural ecosystems.
