The Sun affects physical phenomena on Earth in multiple ways. In particular, the material in interplanetary space comes from coronal expansion in the form of inhomogeneous plasma flow （solar wind）, which is the prim...The Sun affects physical phenomena on Earth in multiple ways. In particular, the material in interplanetary space comes from coronal expansion in the form of inhomogeneous plasma flow （solar wind）, which is the primary source of the interplanetary medium. Ground-based Interplanetary Scintillation （IPS） observations are an important and effective method for measuring solar wind speed and the structures of small diameter radio sources. We discuss one mode of ground-based single-station observations： Single-Station Single-Frequency （SSSF） mode. To study the SSSF mode, a new system has been established at Urumqi Astronomical Observatory （UAO）, China, and a series of experimental observations were successfully carried out from May to December, 2008.展开更多
BACKGROUND Sacrococcygeal hernia is a very rare condition that is usually secondary to sacrococcygectomy, and its ideal treatment regimen is unclear. Herein, we report a case of sacrococcygeal hernia occurring in a pa...BACKGROUND Sacrococcygeal hernia is a very rare condition that is usually secondary to sacrococcygectomy, and its ideal treatment regimen is unclear. Herein, we report a case of sacrococcygeal hernia occurring in a patient who had no history of sacrococcygeal operation, present the operative procedures of mesh repair via a combined laparoscopic and sacrococcygeal approach that has not been described,and discuss our experience in diagnosis and treatment with a review of the literature.CASE SUMMARY A 54-year-old woman who chiefly complained of a 10-year history of a reversible bulge in her right sacrococcygeal region was admitted to our hospital. The physical examination revealed a bulge in the right sacrococcygeal region upon standing, which disappeared in the prone position but relapsed when performing the Valsalva manoeuvre. Computed tomography displayed an abnormality in the structure of the tissues between the midline of the sacrococcygeal region and the right gluteus muscle. The patient was diagnosed with sacrococcygeal hernia and received hernia repair with mesh through a combined laparoscopic and sacrococcygeal approach. On laparoscopy, the rectum was dissected posterolaterally, and a defect was identified in the right anterior sacrococcygeal region through which part of the rectum protruded. This was followed by the placement of a self-gripping polyester mesh via a sacrococcygeal approach. There were no postoperative complications. The patient was discharged on postoperative day 7 and was followed for more than 6 mo with no recurrence.CONCLUSION Laparoscopic mesh repair is recommended as a priority of surgical options for sacrococcygeal hernias, while choosing a self-gripping mesh can help avoid the risk of presacral vessel injury by reducing suture fixation.展开更多
There has been great progress recently in the study of radio variability, including the phenomenon of intraday variability（IDV） which occurs on short timescales of 50 h or less. There are two common explanations for...There has been great progress recently in the study of radio variability, including the phenomenon of intraday variability（IDV） which occurs on short timescales of 50 h or less. There are two common explanations for IDV： an intrinsic mechanism or the effect of radio propagation through the interstellar medium. We consider the case of refractive interstellar scintillation（RISS）, an extrinsic cause of radio variability. We theoretically derive the structure function of the ‘thick screen’RISS model by using an approximation method, and discuss its application to the IDV phenomenon with some simulated results. Finally, the IDV source J1128＋5925 is fitted with the ‘thin screen’ RISS model. Some possible combinations of parameters, namely source size, distance and relative velocity of the scattering screen, are presented.展开更多
基金supported by the National Meridian Project (Grant No [2006]2176)
文摘The Sun affects physical phenomena on Earth in multiple ways. In particular, the material in interplanetary space comes from coronal expansion in the form of inhomogeneous plasma flow （solar wind）, which is the primary source of the interplanetary medium. Ground-based Interplanetary Scintillation （IPS） observations are an important and effective method for measuring solar wind speed and the structures of small diameter radio sources. We discuss one mode of ground-based single-station observations： Single-Station Single-Frequency （SSSF） mode. To study the SSSF mode, a new system has been established at Urumqi Astronomical Observatory （UAO）, China, and a series of experimental observations were successfully carried out from May to December, 2008.
文摘BACKGROUND Sacrococcygeal hernia is a very rare condition that is usually secondary to sacrococcygectomy, and its ideal treatment regimen is unclear. Herein, we report a case of sacrococcygeal hernia occurring in a patient who had no history of sacrococcygeal operation, present the operative procedures of mesh repair via a combined laparoscopic and sacrococcygeal approach that has not been described,and discuss our experience in diagnosis and treatment with a review of the literature.CASE SUMMARY A 54-year-old woman who chiefly complained of a 10-year history of a reversible bulge in her right sacrococcygeal region was admitted to our hospital. The physical examination revealed a bulge in the right sacrococcygeal region upon standing, which disappeared in the prone position but relapsed when performing the Valsalva manoeuvre. Computed tomography displayed an abnormality in the structure of the tissues between the midline of the sacrococcygeal region and the right gluteus muscle. The patient was diagnosed with sacrococcygeal hernia and received hernia repair with mesh through a combined laparoscopic and sacrococcygeal approach. On laparoscopy, the rectum was dissected posterolaterally, and a defect was identified in the right anterior sacrococcygeal region through which part of the rectum protruded. This was followed by the placement of a self-gripping polyester mesh via a sacrococcygeal approach. There were no postoperative complications. The patient was discharged on postoperative day 7 and was followed for more than 6 mo with no recurrence.CONCLUSION Laparoscopic mesh repair is recommended as a priority of surgical options for sacrococcygeal hernias, while choosing a self-gripping mesh can help avoid the risk of presacral vessel injury by reducing suture fixation.
基金Supported by the National Natural Science Foundation of China
文摘There has been great progress recently in the study of radio variability, including the phenomenon of intraday variability（IDV） which occurs on short timescales of 50 h or less. There are two common explanations for IDV： an intrinsic mechanism or the effect of radio propagation through the interstellar medium. We consider the case of refractive interstellar scintillation（RISS）, an extrinsic cause of radio variability. We theoretically derive the structure function of the ‘thick screen’RISS model by using an approximation method, and discuss its application to the IDV phenomenon with some simulated results. Finally, the IDV source J1128＋5925 is fitted with the ‘thin screen’ RISS model. Some possible combinations of parameters, namely source size, distance and relative velocity of the scattering screen, are presented.
