Air element concept and Composite Element Method (CEM) were introduced inthis paper firstly, and then an explicit drainage holes element model was developed. The mainadvantage of the new model is that it allows draina...Air element concept and Composite Element Method (CEM) were introduced inthis paper firstly, and then an explicit drainage holes element model was developed. The mainadvantage of the new model is that it allows drainage holes to be located within soil elements.Therefore the mesh generation of complicated geotechnical structures with a large number of seepagedrainage holes becomes relatively convenient and feasible. This will further facilitate the optimaldesign of seepage control system, and in this case the calculation mesh can be kept unchanged whenthe number, position and orientation of drainage holes are adjusted. The model was been implementedin software. A sluice foundation seepage control problem was studied, by which the validity and therobustness of the new model were verified.展开更多
BACKGROUND Chronic subdural hematoma(CSDH)is a common disease in neurosurgery.The traditional treatment methods include burr hole drainage,bone flap craniectomy and other surgical methods,and there are certain complic...BACKGROUND Chronic subdural hematoma(CSDH)is a common disease in neurosurgery.The traditional treatment methods include burr hole drainage,bone flap craniectomy and other surgical methods,and there are certain complications such as recurrence,pneumocephalus,infection and so on.With the promotion of neuroendoscopic technology,its treatment effect and advantages need to be further evaluated.AIM To study the clinical effect of endoscopic small-bone approach in CSDH.METHODS A total of 122 patients with CSDH admitted to our hospital from August 2018 to August 2021 were randomly divided into two groups using the digital table method:the neuroendoscopy group(n=61 cases)and the burr hole drainage group(n=61 cases).The clinical treatment effect of the two groups of patients with CSDH was compared.RESULTS At the early postoperative stage(1 d and 3 d),the proportion of 1/2 re-expansion of brain tissue in the hematoma cavity and the proportion of complete reexpansion was higher in the neuroendoscopy group than in the burr hole drainage group,and the difference between the two groups was statistically significant(P<0.05).The recurrence rate of hematoma in the neuroendoscopy group was lower than that in the burr hole drainage group,and the difference between the two groups was statistically significant(P<0.05).No intracranial hematoma,low cranial pressure,tension pneumocephalus or other complications occurred in the neuroendoscopy group.CONCLUSION The neuroendoscopic approach for the treatment of CSDH can clear the hematoma under direct vision and separate the mucosal lace-up.The surgical effect is apparent with few complications and definite curative effect,which is worthy of clinical promotion and application.展开更多
Background: Chronic subdural hematoma is a common neurosurgical condition especially in the aging population.Burr hole for drainage is an effective treatment, yet recurrence is reported at 8 to 22 ％ worldwide, and 1-...Background: Chronic subdural hematoma is a common neurosurgical condition especially in the aging population.Burr hole for drainage is an effective treatment, yet recurrence is reported at 8 to 22 ％ worldwide, and 1-year mortality rates could be as high as 32 ％.Our previous study on the use of dexamethasone as a primary nonsurgical treatment showed good response in selected group of patients.This study aims to assess the efficacy of dexamethasone with surgical drainage in the reduction of recurrence requiring reoperation.Methods: From October 2000 to September 2006, patients with chronic subdural hematoma admitted to the Prince of Wales Hospital, The Chinese University of Hong Kong, were randomized to surgical drainage with steroid versus surgical drainage only.The primary endpoint was symptomatic recurrence requiring reoperation.Results: Two hundred forty-eight patients were recruited and consented for the randomization during the study period.One hundred twenty-two received both surgery and steroid (the intervention arm) while 126 received surgery only (the control arm).The recurrence rate requiring reoperation was 6.6 ％ (8/122) and 13.5 ％ (17/126),respectively (p =0.109).There was no significant difference in complications such as chest infection (p =0.201) or wound infection (p =0.987).Favorable outcome (Glasgow Outcome Score 4-5) was 104/122 (85.2 ％) in the intervention group versus 105/126 (83.3 ％) in the control group, respectively (p =0.811).Based on the recurrence rate in our study, we generate a potential sample size of at least 594 patients (type Ⅰ error =5 ％, power =80 ％,two-sided test) to detect a significant difference.Conclusions, brief summary, and potential implications: In this prospective pilot phase IIB randomized controlled study, steroid with surgical drainage had a lower recurrence with reoperation though statistically insignificant.It was safe with no significant difference in complication rates.This pilot study generates a potential sample size for a definitive larger double-blinded randomized controlled trial in the future.展开更多
Based on the basic principle of the finite element method, the implicit composite element method for numerical simulation of seepage in underground engineering is proposed. In the simulation, the faults and drainage h...Based on the basic principle of the finite element method, the implicit composite element method for numerical simulation of seepage in underground engineering is proposed. In the simulation, the faults and drainage holes are set implicitly in the model elements without adding additional elements. Elements containing fault or drainage-hole data are termed composite elements. Then, their information data in model could be obtained. By determining the osmotic transmission matrix of the composite elements, the permeability coefficient matrix is then obtained. The method was applied to the numerical simulation of the seepage field around the underground powerhouse of the Ganhe Pumping Station in Yunnan, China, using a compiled three-dimensional finite element method calculation program. The rock mass around the site includes two faults. The seepage field in the rock mass was analyzed at different stages of the engineering project. The results show that, before the excavation of the underground caverns, the rock mass seepage is affected by the faults and the groundwater permeated down along the tangential fault plane. After the excavation of the caverns during the operation period, the groundwater is basically drained away and the underground caverns are mostly above the groundwater level. Thus, the calculation results of the engineering example verify the implicit composite method for the simulation of faults and drainage holes. This method can well meet the calculation demands of practical engineering.展开更多
文摘Air element concept and Composite Element Method (CEM) were introduced inthis paper firstly, and then an explicit drainage holes element model was developed. The mainadvantage of the new model is that it allows drainage holes to be located within soil elements.Therefore the mesh generation of complicated geotechnical structures with a large number of seepagedrainage holes becomes relatively convenient and feasible. This will further facilitate the optimaldesign of seepage control system, and in this case the calculation mesh can be kept unchanged whenthe number, position and orientation of drainage holes are adjusted. The model was been implementedin software. A sluice foundation seepage control problem was studied, by which the validity and therobustness of the new model were verified.
基金the Science and Technology Program of Nantong Health Committee,No.MA2019003,No.MA2021017,No.MB2021026,and No.MB2021027Science and Technology Program of Nantong City,No.Key003 and No.JCZ2022040and Kangda College of Nanjing Medical University,No.KD2021JYYJYB025。
文摘BACKGROUND Chronic subdural hematoma(CSDH)is a common disease in neurosurgery.The traditional treatment methods include burr hole drainage,bone flap craniectomy and other surgical methods,and there are certain complications such as recurrence,pneumocephalus,infection and so on.With the promotion of neuroendoscopic technology,its treatment effect and advantages need to be further evaluated.AIM To study the clinical effect of endoscopic small-bone approach in CSDH.METHODS A total of 122 patients with CSDH admitted to our hospital from August 2018 to August 2021 were randomly divided into two groups using the digital table method:the neuroendoscopy group(n=61 cases)and the burr hole drainage group(n=61 cases).The clinical treatment effect of the two groups of patients with CSDH was compared.RESULTS At the early postoperative stage(1 d and 3 d),the proportion of 1/2 re-expansion of brain tissue in the hematoma cavity and the proportion of complete reexpansion was higher in the neuroendoscopy group than in the burr hole drainage group,and the difference between the two groups was statistically significant(P<0.05).The recurrence rate of hematoma in the neuroendoscopy group was lower than that in the burr hole drainage group,and the difference between the two groups was statistically significant(P<0.05).No intracranial hematoma,low cranial pressure,tension pneumocephalus or other complications occurred in the neuroendoscopy group.CONCLUSION The neuroendoscopic approach for the treatment of CSDH can clear the hematoma under direct vision and separate the mucosal lace-up.The surgical effect is apparent with few complications and definite curative effect,which is worthy of clinical promotion and application.
文摘Background: Chronic subdural hematoma is a common neurosurgical condition especially in the aging population.Burr hole for drainage is an effective treatment, yet recurrence is reported at 8 to 22 ％ worldwide, and 1-year mortality rates could be as high as 32 ％.Our previous study on the use of dexamethasone as a primary nonsurgical treatment showed good response in selected group of patients.This study aims to assess the efficacy of dexamethasone with surgical drainage in the reduction of recurrence requiring reoperation.Methods: From October 2000 to September 2006, patients with chronic subdural hematoma admitted to the Prince of Wales Hospital, The Chinese University of Hong Kong, were randomized to surgical drainage with steroid versus surgical drainage only.The primary endpoint was symptomatic recurrence requiring reoperation.Results: Two hundred forty-eight patients were recruited and consented for the randomization during the study period.One hundred twenty-two received both surgery and steroid (the intervention arm) while 126 received surgery only (the control arm).The recurrence rate requiring reoperation was 6.6 ％ (8/122) and 13.5 ％ (17/126),respectively (p =0.109).There was no significant difference in complications such as chest infection (p =0.201) or wound infection (p =0.987).Favorable outcome (Glasgow Outcome Score 4-5) was 104/122 (85.2 ％) in the intervention group versus 105/126 (83.3 ％) in the control group, respectively (p =0.811).Based on the recurrence rate in our study, we generate a potential sample size of at least 594 patients (type Ⅰ error =5 ％, power =80 ％,two-sided test) to detect a significant difference.Conclusions, brief summary, and potential implications: In this prospective pilot phase IIB randomized controlled study, steroid with surgical drainage had a lower recurrence with reoperation though statistically insignificant.It was safe with no significant difference in complication rates.This pilot study generates a potential sample size for a definitive larger double-blinded randomized controlled trial in the future.
基金supported by the National Key Basic Research Program of China(Grant No.2015CB057904)the Major Program of the National Natural Science Foundation of China(Grant No.91215301)+1 种基金the National Natural Science Foundation of China(Grant Nos.51279136&51209164)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20130141110015)
文摘Based on the basic principle of the finite element method, the implicit composite element method for numerical simulation of seepage in underground engineering is proposed. In the simulation, the faults and drainage holes are set implicitly in the model elements without adding additional elements. Elements containing fault or drainage-hole data are termed composite elements. Then, their information data in model could be obtained. By determining the osmotic transmission matrix of the composite elements, the permeability coefficient matrix is then obtained. The method was applied to the numerical simulation of the seepage field around the underground powerhouse of the Ganhe Pumping Station in Yunnan, China, using a compiled three-dimensional finite element method calculation program. The rock mass around the site includes two faults. The seepage field in the rock mass was analyzed at different stages of the engineering project. The results show that, before the excavation of the underground caverns, the rock mass seepage is affected by the faults and the groundwater permeated down along the tangential fault plane. After the excavation of the caverns during the operation period, the groundwater is basically drained away and the underground caverns are mostly above the groundwater level. Thus, the calculation results of the engineering example verify the implicit composite method for the simulation of faults and drainage holes. This method can well meet the calculation demands of practical engineering.
