Cryopreservation of few spermatozoa is still a major challenge for male fertility preservation. This study reports use a new micro-straw （LSL straw） for freezing few spermatozoa for intracytoplasmic sperm injection ...Cryopreservation of few spermatozoa is still a major challenge for male fertility preservation. This study reports use a new micro-straw （LSL straw） for freezing few spermatozoa for intracytoplasmic sperm injection （ICSI）. Semen samples from 22 fertile donors were collected, and each semen sample was diluted and mixed with cryoprotectant in a ratio of 1：1, and then frozen using three different straws such as LSL straw （50-100μl）, traditional 0.25 ml and 0.5 ml straws. For freezing, all straws were fumigated with liquid nitrogen, with temperature directly reducing to -130--140℃. Sperm concentration, progressive motility, morphology, acrosome integrity, and DNA fragmentation index were evaluated before and after freezing. After freezing-thawing, LSL straw group had significantly higher percentage of sperm motility than traditional 0.25 ml and 0.5 ml straw groups （38.5% vs 27.4% and 25.6%, P 〈 0.003）. Sperm motility and acrosomal integrity after freezing-thawing were significantly lower than that of before freezing. However, there was no significant difference in morphology, acrosome, and DNA integrity between the three types of straws （P 〉 0.05）. As LSL straws were thinner and hold very small volume, the freezing rate of LSL straw was obviously faster than 0.25 ml straw and 0.5 ml straws. In conclusion, LSL micro-straws may be useful to store few motile spermatozoa with good recovery of motility for patients undergoing ICSI treatment.展开更多
In order to control the noise of the heavy truck interior cab effectively, the active noise control methods are employed. First, an interior noise field test for the heavy truck is performed, and frequencies of interi...In order to control the noise of the heavy truck interior cab effectively, the active noise control methods are employed. First, an interior noise field test for the heavy truck is performed, and frequencies of interior noise of this vehicle are analyzed. According to the spectrum analysis of acquired noise signal, it is found out that the main frequencies of interior noise are less than 800Hz. Then the least squares lattice （LSL） algorithm is used as signal processing algorithm of the controller and a closed-loop control DSP system, based on TMS 320VC5416, is developed. The residual signal at driver＇s ear is used as feedback signal. Lastly, the developed ANC system is loaded into the heavy truck cab, and controlling the noise at driver＇ s ear for that truck at different driving speeds is attempted. The noise control test results indicate that the cab interior noise is reduced averagely by 0.9 dBA at different driving speeds.展开更多
文摘Cryopreservation of few spermatozoa is still a major challenge for male fertility preservation. This study reports use a new micro-straw （LSL straw） for freezing few spermatozoa for intracytoplasmic sperm injection （ICSI）. Semen samples from 22 fertile donors were collected, and each semen sample was diluted and mixed with cryoprotectant in a ratio of 1：1, and then frozen using three different straws such as LSL straw （50-100μl）, traditional 0.25 ml and 0.5 ml straws. For freezing, all straws were fumigated with liquid nitrogen, with temperature directly reducing to -130--140℃. Sperm concentration, progressive motility, morphology, acrosome integrity, and DNA fragmentation index were evaluated before and after freezing. After freezing-thawing, LSL straw group had significantly higher percentage of sperm motility than traditional 0.25 ml and 0.5 ml straw groups （38.5% vs 27.4% and 25.6%, P 〈 0.003）. Sperm motility and acrosomal integrity after freezing-thawing were significantly lower than that of before freezing. However, there was no significant difference in morphology, acrosome, and DNA integrity between the three types of straws （P 〉 0.05）. As LSL straws were thinner and hold very small volume, the freezing rate of LSL straw was obviously faster than 0.25 ml straw and 0.5 ml straws. In conclusion, LSL micro-straws may be useful to store few motile spermatozoa with good recovery of motility for patients undergoing ICSI treatment.
基金Sponsored by the National Natural Science Foundation of China (50875022)Research Foundation of Beijing Institute of Technology(20070342012)
文摘In order to control the noise of the heavy truck interior cab effectively, the active noise control methods are employed. First, an interior noise field test for the heavy truck is performed, and frequencies of interior noise of this vehicle are analyzed. According to the spectrum analysis of acquired noise signal, it is found out that the main frequencies of interior noise are less than 800Hz. Then the least squares lattice （LSL） algorithm is used as signal processing algorithm of the controller and a closed-loop control DSP system, based on TMS 320VC5416, is developed. The residual signal at driver＇s ear is used as feedback signal. Lastly, the developed ANC system is loaded into the heavy truck cab, and controlling the noise at driver＇ s ear for that truck at different driving speeds is attempted. The noise control test results indicate that the cab interior noise is reduced averagely by 0.9 dBA at different driving speeds.
