The relationship between the automatic control method and the stability of the open canal is studied by means of numerical simulation of unsteady flow in an open canal under different methods of control. It is found t...The relationship between the automatic control method and the stability of the open canal is studied by means of numerical simulation of unsteady flow in an open canal under different methods of control. It is found the Proportional-Proportional plus Reset （P＋PR） control is more reliable than the Linear Quadratic Regulator （LQR） control. Moreover, for the P＋PR control, the hydraulic response of the constant volume method of operation is better than that of the constant downstream depth method in the type of centrally controlled canal. Therefore, an appropriate flow change rate should be chosen instead of shortening the pool length to reach an acceptable drawdown rate. For the canal with a bottom width of 40 m, side slope of 3, Manning n of 0.015, bottom slope of 0.000 04, and design flow of 600 m3/s, the pool length of more than 30 km can provide acceptable drawdown rates of 0.2 m/h when a proper flow change rate is chosen.展开更多
The author establishes the exact boundary observability of unsteady supercritical flows in a tree-like network of open canals with general topology. An implicit duality between the exact boundary controllability and t...The author establishes the exact boundary observability of unsteady supercritical flows in a tree-like network of open canals with general topology. An implicit duality between the exact boundary controllability and the exact boundary observability is also given for unsteady supercritical flows.展开更多
AIM: To study the long-term efficacy and safety of modified viscocanalostomy in Chinese people with open angle glaucoma(OAG).METHODS: This retrospective study included a total of 100 eyes from 100 Chinese patients wit...AIM: To study the long-term efficacy and safety of modified viscocanalostomy in Chinese people with open angle glaucoma(OAG).METHODS: This retrospective study included a total of 100 eyes from 100 Chinese patients with medically uncontrolled OAG. All the patients underwent modified viscocanalostomy with injection of viscoelastic material in the surgically created ostia of Schlemm's canal(SC). The modifications included peeling of the inner wall of SC and the juxtacanalicular meshwork, use of mitomycin C, and loosely suturing the superficial scleral flap. Intraocular pressure(IOP), visual acuity, number of medications, laser goniopuncture data and complications were recorded. The definition of complete(qualified) success was an IOP equal to or lower than 21, 18, 16 mm Hg without(with or without) anti-glaucoma medications. RESULTS: The mean IOP was 33.5±9.9 mm Hg before surgery, 15.2±3.6 mm Hg(mean IOP reduction of 51%) at 5 y after surgery, and 15.6±2.8 mm Hg(mean IOP reduction of 49.9%) at 10 y after surgery(P<0.001). The number of anti-glaucoma medications dropped from 2.39±0.5 preoperatively to 0.47±0.8 at 5 y and 0.67±0.8 at 10 y postoperatively(P<0.001). The follow-up period was 104.5±37.0 mo. The qualified success rate for an IOP of 21, 18 or 16 mm Hg or less was 84% [95% confidence interval(CI): 0.80-0.88], 73%(95%CI: 0.68-0.78), and 59%(95%CI: 0.52-0.66) after 5 y, and 80%(95%CI: 0.76-0.84), 69%(95%CI: 0.64-0.74), 51%(95%CI: 0.44-0.58) after 10 y, respectively. There was a relationship between age, preoperative IOP and success rate(P<0.01, P<0.05). A total of 31 eyes(31.3%)in 31 patients underwent laser goniopuncture, decreasing the IOP from 22.9±4.3 mm Hg to 16.3±2.5 mm Hg(P<0.01). Neither blebitis nor endophthalmitis occurred.CONCLUSION: Modified viscocanalostomy could be performed to lower IOP, decrease multiple anti-glaucoma drops use as well. It's a safe procedure with less complications over 10 y in Chinese individuals with OAG.展开更多
Most animal spinal cord injury models involve a laminectomy,such as the weight drop model or the transection model.However,in clinical practice,many patients undergo spinal cord injury while maintaining a relatively c...Most animal spinal cord injury models involve a laminectomy,such as the weight drop model or the transection model.However,in clinical practice,many patients undergo spinal cord injury while maintaining a relatively complete spinal canal.Thus,open spinal cord injury models often do not simulate real injuries,and few previous studies have investigated whether having a closed spinal canal after a primary spinal cord injury may influence secondary processes.Therefore,we aimed to assess the differences in neurological dysfunction and pathological changes between rat spinal cord injury models with closed and open spinal canals.Sprague-Dawley rats were randomly divided into three groups.In the sham group,the tunnel was expanded only,without inserting a screw into the spinal canal.In the spinal cord injury with open canal group,a screw was inserted into the spinal canal to cause spinal cord injury for 5 minutes,and then the screw was pulled out,leaving a hole in the vertebral plate.In the spinal cord injury with closed canal group,after inserting a screw into the spinal canal for 5 minutes,the screw was pulled out by approximately 1.5 mm and the flat end of the screw remained in the hole in the vertebral plate so that the spinal canal remained closed;this group was the modified model,which used a screw both to compress the spinal cord and to seal the spinal canal.At 7 days post-operation,the Basso-Beattie-Bresnahan scale was used to measure changes in neurological outcomes.Hematoxylin-eosin staining was used to assess histopathology.To evaluate the degree of local secondary hypoxia,immunohistochemical staining and western blot assays were applied to detect the expression of hypoxia-inducible factor 1α(HIF-1α)and vascular endothelial growth factor(VEGF).Compared with the spinal cord injury with open canal group,in the closed canal group the Basso-Beattie-Bresnahan scores were lower,cell morphology was more irregular,the percentage of morphologically normal neurons was lower,the percentages of HIF-1α-and VEGF-immunoreactive cells were higher,and HIF-1αand VEGF protein expression was also higher.In conclusion,we successfully established a rat spinal cord injury model with closed canal.This model could result in more serious neurological dysfunction and histopathological changes than in open canal models.All experimental procedures were approved by the Institutional Animal Care Committee of Shanghai Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine,China(approval No.HKDL201810)on January 30,2018.展开更多
基金Supported by the National Natural Science Foundation of China (51039007, 50979076)the National Basic Research Program of China (973 Program) (2010CB428802)the Open Research Fund of Key Laboratory for Water Requirement and Regulation, Ministry of Agriculture (CWRR200901)
文摘The relationship between the automatic control method and the stability of the open canal is studied by means of numerical simulation of unsteady flow in an open canal under different methods of control. It is found the Proportional-Proportional plus Reset （P＋PR） control is more reliable than the Linear Quadratic Regulator （LQR） control. Moreover, for the P＋PR control, the hydraulic response of the constant volume method of operation is better than that of the constant downstream depth method in the type of centrally controlled canal. Therefore, an appropriate flow change rate should be chosen instead of shortening the pool length to reach an acceptable drawdown rate. For the canal with a bottom width of 40 m, side slope of 3, Manning n of 0.015, bottom slope of 0.000 04, and design flow of 600 m3/s, the pool length of more than 30 km can provide acceptable drawdown rates of 0.2 m/h when a proper flow change rate is chosen.
文摘The author establishes the exact boundary observability of unsteady supercritical flows in a tree-like network of open canals with general topology. An implicit duality between the exact boundary controllability and the exact boundary observability is also given for unsteady supercritical flows.
文摘AIM: To study the long-term efficacy and safety of modified viscocanalostomy in Chinese people with open angle glaucoma(OAG).METHODS: This retrospective study included a total of 100 eyes from 100 Chinese patients with medically uncontrolled OAG. All the patients underwent modified viscocanalostomy with injection of viscoelastic material in the surgically created ostia of Schlemm's canal(SC). The modifications included peeling of the inner wall of SC and the juxtacanalicular meshwork, use of mitomycin C, and loosely suturing the superficial scleral flap. Intraocular pressure(IOP), visual acuity, number of medications, laser goniopuncture data and complications were recorded. The definition of complete(qualified) success was an IOP equal to or lower than 21, 18, 16 mm Hg without(with or without) anti-glaucoma medications. RESULTS: The mean IOP was 33.5±9.9 mm Hg before surgery, 15.2±3.6 mm Hg(mean IOP reduction of 51%) at 5 y after surgery, and 15.6±2.8 mm Hg(mean IOP reduction of 49.9%) at 10 y after surgery(P<0.001). The number of anti-glaucoma medications dropped from 2.39±0.5 preoperatively to 0.47±0.8 at 5 y and 0.67±0.8 at 10 y postoperatively(P<0.001). The follow-up period was 104.5±37.0 mo. The qualified success rate for an IOP of 21, 18 or 16 mm Hg or less was 84% [95% confidence interval(CI): 0.80-0.88], 73%(95%CI: 0.68-0.78), and 59%(95%CI: 0.52-0.66) after 5 y, and 80%(95%CI: 0.76-0.84), 69%(95%CI: 0.64-0.74), 51%(95%CI: 0.44-0.58) after 10 y, respectively. There was a relationship between age, preoperative IOP and success rate(P<0.01, P<0.05). A total of 31 eyes(31.3%)in 31 patients underwent laser goniopuncture, decreasing the IOP from 22.9±4.3 mm Hg to 16.3±2.5 mm Hg(P<0.01). Neither blebitis nor endophthalmitis occurred.CONCLUSION: Modified viscocanalostomy could be performed to lower IOP, decrease multiple anti-glaucoma drops use as well. It's a safe procedure with less complications over 10 y in Chinese individuals with OAG.
文摘Most animal spinal cord injury models involve a laminectomy,such as the weight drop model or the transection model.However,in clinical practice,many patients undergo spinal cord injury while maintaining a relatively complete spinal canal.Thus,open spinal cord injury models often do not simulate real injuries,and few previous studies have investigated whether having a closed spinal canal after a primary spinal cord injury may influence secondary processes.Therefore,we aimed to assess the differences in neurological dysfunction and pathological changes between rat spinal cord injury models with closed and open spinal canals.Sprague-Dawley rats were randomly divided into three groups.In the sham group,the tunnel was expanded only,without inserting a screw into the spinal canal.In the spinal cord injury with open canal group,a screw was inserted into the spinal canal to cause spinal cord injury for 5 minutes,and then the screw was pulled out,leaving a hole in the vertebral plate.In the spinal cord injury with closed canal group,after inserting a screw into the spinal canal for 5 minutes,the screw was pulled out by approximately 1.5 mm and the flat end of the screw remained in the hole in the vertebral plate so that the spinal canal remained closed;this group was the modified model,which used a screw both to compress the spinal cord and to seal the spinal canal.At 7 days post-operation,the Basso-Beattie-Bresnahan scale was used to measure changes in neurological outcomes.Hematoxylin-eosin staining was used to assess histopathology.To evaluate the degree of local secondary hypoxia,immunohistochemical staining and western blot assays were applied to detect the expression of hypoxia-inducible factor 1α(HIF-1α)and vascular endothelial growth factor(VEGF).Compared with the spinal cord injury with open canal group,in the closed canal group the Basso-Beattie-Bresnahan scores were lower,cell morphology was more irregular,the percentage of morphologically normal neurons was lower,the percentages of HIF-1α-and VEGF-immunoreactive cells were higher,and HIF-1αand VEGF protein expression was also higher.In conclusion,we successfully established a rat spinal cord injury model with closed canal.This model could result in more serious neurological dysfunction and histopathological changes than in open canal models.All experimental procedures were approved by the Institutional Animal Care Committee of Shanghai Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine,China(approval No.HKDL201810)on January 30,2018.
