The use of contraceptive method to avoid pregnancy is a multifaceted phenomenon. Worldwide, 20 percent of married women of reproductive age are currently using periodic abstinence. To assess the knowledge and practice...The use of contraceptive method to avoid pregnancy is a multifaceted phenomenon. Worldwide, 20 percent of married women of reproductive age are currently using periodic abstinence. To assess the knowledge and practice of periodic abstinence among currently married pregnant women, data were collected from the pregnant women attending the Department of Obstetrics and Gynaecology, All India Institute of Medical Sciences, New Delhi, India. One thousand three hundred and thirty one (1331) currently married pregnant women were interviewed face-to-face. Approximately 29.3 percent of women were aware of the abstinence method, 11.5 percent women had history of using it. In-depth finding shows that 84.9 percent women did not have correct knowledge of fertile window of a menstrual cycle. Counseling about the correct fertile window of a menstrual cycle may increase the effectiveness of methods and hence reduce the incidence of unwanted pregnancies.展开更多
In this paper we report on a continuous-wave （CW） intracavity singly resonant optical parametric oscillator （ICSRO） based on periodically poled LiNbO3 （PPLN） pumped by a diode-end-pumped CW Nd：YVO4 laser. Consi...In this paper we report on a continuous-wave （CW） intracavity singly resonant optical parametric oscillator （ICSRO） based on periodically poled LiNbO3 （PPLN） pumped by a diode-end-pumped CW Nd：YVO4 laser. Considering the thermal lens effects and diffraction loss, an optical ballast lens and a near-concentric cavity are adopted for better operation. Through varying the grating period and the temperature, the tunable signal output from 1406 nm to 1513 nm is obtained. At a PPLN grating period of 29 pm and a temperature of 413 K, a maximum signal output power of 820 mW at 1500 nm is achieved when the 808 nm pump power is 10.9 W, leading to an optical-to-optical conversion efficiency of 7.51%.展开更多
We report an efficient continuous-wave （CW） tunable intra-cavity singly resonant optical parametric oscillator based on the multi-period periodically poled lithium niobate and using a laser diode （LD） end-pumped C...We report an efficient continuous-wave （CW） tunable intra-cavity singly resonant optical parametric oscillator based on the multi-period periodically poled lithium niobate and using a laser diode （LD） end-pumped CW 1064 nm Nd：YVO4 laser as the pump source. A highly efficiency CW operation is realized through a careful cavity design for mode matching and thermal stability. The signal tuning range is 1401 1500 nm obtained by varying the domain period. The maximum output power of 2.2 W at 1500 nm is obtained with a 17.1 W 808 nm LD power and the corresponding conversion efficiency is 12.9%.展开更多
【目的】评价经鼻高流量吸氧在全麻诱导前行预充氧的有效性及在插管期延长"安全窒息时限"的效果。【方法】随机将80例非困难气道病例纳入全麻面罩组(FM)、全麻面罩复合经鼻高流量吸氧组(FM+HFNCI)、经鼻高流量吸氧组(HFNCI)...【目的】评价经鼻高流量吸氧在全麻诱导前行预充氧的有效性及在插管期延长"安全窒息时限"的效果。【方法】随机将80例非困难气道病例纳入全麻面罩组(FM)、全麻面罩复合经鼻高流量吸氧组(FM+HFNCI)、经鼻高流量吸氧组(HFNCI)以及经鼻高流量吸氧复合鼻咽通气道组(HFNCI+NPA)。麻醉诱导前预充氧阶段,FM及FM+HFNCI组经全麻面罩而HFNCI及HFNCI+NPA组经鼻导管行预充氧;在气管插管期,除FM组外,余患者均接受经鼻高流量氧吹入。记录不同时点血氧分压、血氧饱和度、心率及血压。【结果】预充氧结束时,PaO_2值、SaO_2值在各组间差异无统计学意义(P>0.05)。窒息插管期,PaO_2值在FM组下降明显,而在HFNCI+NPA组上升;FM组ΔPaO_2值最大(均数为-5.4 k Pa),与其余组比较(ΔPaO_2值均数在FM+HFNCI、HFNCI及HFNCI+NPA组分别为-0.5、-0.8、1.4 k Pa)差异有统计学意义(P<0.001)。插管成功时FM、FM+HFNCI、HFNCI、HFNCI+NPA组PaO_2值(均数分别为46.7、48.3、37.7、43.7 k Pa)、SaO_2值(均数分别为99.7%、99.8%、99.4%、99.7%)均远高于各自安全低限值。【结论】HFNCI用于非困难气道病例,麻醉诱导前预充氧有效性高、可能延长"安全窒息时限",提高围插管期安全;为达最佳氧合效果,实施HFNCI时应保证气道通畅。展开更多
文摘The use of contraceptive method to avoid pregnancy is a multifaceted phenomenon. Worldwide, 20 percent of married women of reproductive age are currently using periodic abstinence. To assess the knowledge and practice of periodic abstinence among currently married pregnant women, data were collected from the pregnant women attending the Department of Obstetrics and Gynaecology, All India Institute of Medical Sciences, New Delhi, India. One thousand three hundred and thirty one (1331) currently married pregnant women were interviewed face-to-face. Approximately 29.3 percent of women were aware of the abstinence method, 11.5 percent women had history of using it. In-depth finding shows that 84.9 percent women did not have correct knowledge of fertile window of a menstrual cycle. Counseling about the correct fertile window of a menstrual cycle may increase the effectiveness of methods and hence reduce the incidence of unwanted pregnancies.
基金Project supported partly by the National Natural Science Foundation of China (Grant Nos 60637010 and 60671036)the National Basic Research Program of China (Grant No 2007CB310403)the Tianjin Applied Fundamental Research Project, China(Grant No 07JCZDJC05900)
文摘In this paper we report on a continuous-wave （CW） intracavity singly resonant optical parametric oscillator （ICSRO） based on periodically poled LiNbO3 （PPLN） pumped by a diode-end-pumped CW Nd：YVO4 laser. Considering the thermal lens effects and diffraction loss, an optical ballast lens and a near-concentric cavity are adopted for better operation. Through varying the grating period and the temperature, the tunable signal output from 1406 nm to 1513 nm is obtained. At a PPLN grating period of 29 pm and a temperature of 413 K, a maximum signal output power of 820 mW at 1500 nm is achieved when the 808 nm pump power is 10.9 W, leading to an optical-to-optical conversion efficiency of 7.51%.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.60978021,61178028,and 10804055)the Program for New Century Excellent Talents in University,China(Grant No.NCET-10-0610)+1 种基金the National Basic Research Program of China(Grant No.2007CB310403)the National High Technology Research and Development Program of China(Grant No.2011AA030208)
文摘We report an efficient continuous-wave （CW） tunable intra-cavity singly resonant optical parametric oscillator based on the multi-period periodically poled lithium niobate and using a laser diode （LD） end-pumped CW 1064 nm Nd：YVO4 laser as the pump source. A highly efficiency CW operation is realized through a careful cavity design for mode matching and thermal stability. The signal tuning range is 1401 1500 nm obtained by varying the domain period. The maximum output power of 2.2 W at 1500 nm is obtained with a 17.1 W 808 nm LD power and the corresponding conversion efficiency is 12.9%.
文摘【目的】评价经鼻高流量吸氧在全麻诱导前行预充氧的有效性及在插管期延长"安全窒息时限"的效果。【方法】随机将80例非困难气道病例纳入全麻面罩组(FM)、全麻面罩复合经鼻高流量吸氧组(FM+HFNCI)、经鼻高流量吸氧组(HFNCI)以及经鼻高流量吸氧复合鼻咽通气道组(HFNCI+NPA)。麻醉诱导前预充氧阶段,FM及FM+HFNCI组经全麻面罩而HFNCI及HFNCI+NPA组经鼻导管行预充氧;在气管插管期,除FM组外,余患者均接受经鼻高流量氧吹入。记录不同时点血氧分压、血氧饱和度、心率及血压。【结果】预充氧结束时,PaO_2值、SaO_2值在各组间差异无统计学意义(P>0.05)。窒息插管期,PaO_2值在FM组下降明显,而在HFNCI+NPA组上升;FM组ΔPaO_2值最大(均数为-5.4 k Pa),与其余组比较(ΔPaO_2值均数在FM+HFNCI、HFNCI及HFNCI+NPA组分别为-0.5、-0.8、1.4 k Pa)差异有统计学意义(P<0.001)。插管成功时FM、FM+HFNCI、HFNCI、HFNCI+NPA组PaO_2值(均数分别为46.7、48.3、37.7、43.7 k Pa)、SaO_2值(均数分别为99.7%、99.8%、99.4%、99.7%)均远高于各自安全低限值。【结论】HFNCI用于非困难气道病例,麻醉诱导前预充氧有效性高、可能延长"安全窒息时限",提高围插管期安全;为达最佳氧合效果,实施HFNCI时应保证气道通畅。
