Telescopes with large aspherical primary mirrors collect more light and are therefore sought after by astronomers. Instead of using a single large one-piece mirror, smaller segments can be assembled into a useable tel...Telescopes with large aspherical primary mirrors collect more light and are therefore sought after by astronomers. Instead of using a single large one-piece mirror, smaller segments can be assembled into a useable telescopic primary. Because the segments must fit together to create the effect of a single mirror, segmented optics present unique challenges to the fabrication and testing that are absent in monolithic optics. A dispersed fringe sensor （DFS） using a broadband point source is an efficient method for cophasing and is also highly automated and robust. Unlike the widely adopted Shack- Hartmann Wavefront sensor and curvature wavefront sensor with edge sensors for calibration of relative pistons, DFS can estimate the piston between segments by only using the spectrum formed by the transmissive grating＇s dispersion, and therefore can replace the edge sensors, which are difficult to calibrate. We introduce the theory of the DFS and Dispersed Hartmann Sensor （DHS） for further utilization of the coarse phasing method of DFS. According to the theory, we bring out the preliminary system design of the cophasing experimental system based on DFS and DHS which is now established in our institute. Finally, a summary is reached.展开更多
The free flow of skeletonized ITA grafts was compared with that of pedicled ITA grafts. One hundred patients with coronary artery diseases underwent elective CABG. In the group Ⅰ(n= 50), the left ITA was dissected u...The free flow of skeletonized ITA grafts was compared with that of pedicled ITA grafts. One hundred patients with coronary artery diseases underwent elective CABG. In the group Ⅰ(n= 50), the left ITA was dissected using the skeletonization technique. In the group Ⅱ(n=50), the ITA was harvested as a pedicled graft. Free flow of the ITA was recorded before and 15 min after in- traluminal application of diluted papaverine. Mean arterial pressure was maintained at 9. 31 kPa (70 mmHg). The results showed that before the application of papaverine, free flow of skeletonized and pedicled ITA grafts was identical between the two groups. After treatment with papaverine, the maximum free flow was significantly higher in the skeletonized ITA's in the group Ⅰ(199. 3±69. 6 ml/min) than in the group Ⅱ(145. 7±70. 3 ml/min, P<0. 05). There was on significant differ- ence between the free flow after dilatation of the left and right ITA in the group Ⅰ (left 199. 3±69. 6 ml/mm, right 198. 9±61. 8 ml/mm, respectively). It was concluded that preparation of the ITA with the skeletonization technique resulted in significantly higher free flow capacity than in pedicled grafts and would improve the results of arterial revascularization. The complication rate seems to be lower than with the conventional method.展开更多
Background In clinical practice, there are different surgical approaches for postductal coarctation of the aor- ta （CoA）, with their advantages and disadvantages. Limited studies have reported the surgical outcomes ...Background In clinical practice, there are different surgical approaches for postductal coarctation of the aor- ta （CoA）, with their advantages and disadvantages. Limited studies have reported the surgical outcomes of post- ductal CoA in adolescents and adults. Methods From January 2005 to December 2014, a total of 40 patients aged over 14 years underwent surgical corrections of postductal CoA in our institution. The surgical outcomes as reflected by cardiac function and differences in mean blood pressure of upper and lower extremities both preoper- ative and postoperative were recorded and evaluated. Results Among the 40 patients underwent successful sur- gical corrections, 1 patient complicated by acute aortic dissection and died, while the remainings survived to hos- pital discharge. During the 12-36 month follow-up period, postoperative mean blood pressure differences of upper and lower extremities were significantly reduced as compared with the preoperative data. Postoperative evalu- ation of cardiac function was conducted in all patients with New York Heart Association （NYHA） Ⅰ-Ⅱ. Conclusion For adolescent and adult patients with postductal aortic coarctation, surgical correction is highly recom- mended. Surgical approach should be based on the specific anatomy of the coarctation lesion, concomitant mal- formations, and expected grown-up height. Those complicated with other intracardiac malformations should be treated with extra-anatomical bypass technique and simultaneous surgical correction of CoA, which is effective with desirable postoperative prognosis.展开更多
基金Supported by Key Program of Applied Basic and Frontier Technology Research Foundation of Tianjin(14JCZDJC34400)Special Fund for Modern Agricultural Technology System(CARS-30)Transformation and Extension Of Agricultural Science and Technology Achievements in Tianjin(201304120)~~
基金supported by the National Natural Science Foundation of China(Grant No. 10703008)
文摘Telescopes with large aspherical primary mirrors collect more light and are therefore sought after by astronomers. Instead of using a single large one-piece mirror, smaller segments can be assembled into a useable telescopic primary. Because the segments must fit together to create the effect of a single mirror, segmented optics present unique challenges to the fabrication and testing that are absent in monolithic optics. A dispersed fringe sensor （DFS） using a broadband point source is an efficient method for cophasing and is also highly automated and robust. Unlike the widely adopted Shack- Hartmann Wavefront sensor and curvature wavefront sensor with edge sensors for calibration of relative pistons, DFS can estimate the piston between segments by only using the spectrum formed by the transmissive grating＇s dispersion, and therefore can replace the edge sensors, which are difficult to calibrate. We introduce the theory of the DFS and Dispersed Hartmann Sensor （DHS） for further utilization of the coarse phasing method of DFS. According to the theory, we bring out the preliminary system design of the cophasing experimental system based on DFS and DHS which is now established in our institute. Finally, a summary is reached.
文摘The free flow of skeletonized ITA grafts was compared with that of pedicled ITA grafts. One hundred patients with coronary artery diseases underwent elective CABG. In the group Ⅰ(n= 50), the left ITA was dissected using the skeletonization technique. In the group Ⅱ(n=50), the ITA was harvested as a pedicled graft. Free flow of the ITA was recorded before and 15 min after in- traluminal application of diluted papaverine. Mean arterial pressure was maintained at 9. 31 kPa (70 mmHg). The results showed that before the application of papaverine, free flow of skeletonized and pedicled ITA grafts was identical between the two groups. After treatment with papaverine, the maximum free flow was significantly higher in the skeletonized ITA's in the group Ⅰ(199. 3±69. 6 ml/min) than in the group Ⅱ(145. 7±70. 3 ml/min, P<0. 05). There was on significant differ- ence between the free flow after dilatation of the left and right ITA in the group Ⅰ (left 199. 3±69. 6 ml/mm, right 198. 9±61. 8 ml/mm, respectively). It was concluded that preparation of the ITA with the skeletonization technique resulted in significantly higher free flow capacity than in pedicled grafts and would improve the results of arterial revascularization. The complication rate seems to be lower than with the conventional method.
基金supported by Science and Technology Foundation of Guangzhou(No.2014y2-00052)
文摘Background In clinical practice, there are different surgical approaches for postductal coarctation of the aor- ta （CoA）, with their advantages and disadvantages. Limited studies have reported the surgical outcomes of post- ductal CoA in adolescents and adults. Methods From January 2005 to December 2014, a total of 40 patients aged over 14 years underwent surgical corrections of postductal CoA in our institution. The surgical outcomes as reflected by cardiac function and differences in mean blood pressure of upper and lower extremities both preoper- ative and postoperative were recorded and evaluated. Results Among the 40 patients underwent successful sur- gical corrections, 1 patient complicated by acute aortic dissection and died, while the remainings survived to hos- pital discharge. During the 12-36 month follow-up period, postoperative mean blood pressure differences of upper and lower extremities were significantly reduced as compared with the preoperative data. Postoperative evalu- ation of cardiac function was conducted in all patients with New York Heart Association （NYHA） Ⅰ-Ⅱ. Conclusion For adolescent and adult patients with postductal aortic coarctation, surgical correction is highly recom- mended. Surgical approach should be based on the specific anatomy of the coarctation lesion, concomitant mal- formations, and expected grown-up height. Those complicated with other intracardiac malformations should be treated with extra-anatomical bypass technique and simultaneous surgical correction of CoA, which is effective with desirable postoperative prognosis.
