The use of piezoelectric material sensors in smart composite structures is investigated. An experimental structure bonded with lead zirconate titanate piezoelectric ceramic(PZT) sensors is developed. These bonded sens...The use of piezoelectric material sensors in smart composite structures is investigated. An experimental structure bonded with lead zirconate titanate piezoelectric ceramic(PZT) sensors is developed. These bonded sensors are employed to monitor load variations and transient impacts in the structure. Incorporated with pattern recognition approach, PZT sensors have succeeded in detecting the onset and location of damages.展开更多
Objective To explore the safety and efficacy of frameless stereotactic brain biopsy.Methods Diagnostic accuracy was calculated by comparing biopsy diagnosis with definitive pathology in 62 patients who underwent frame...Objective To explore the safety and efficacy of frameless stereotactic brain biopsy.Methods Diagnostic accuracy was calculated by comparing biopsy diagnosis with definitive pathology in 62 patients who underwent frameless stereotactic brain biopsy between January 2008 and December 2010 in Xiamen University Southeast Hospital.Preoperative characteristics and histological diagnosis were reviewed and then information was analysed to identify factors associated with the biopsy not yielding a diagnosis and complications.Results Diagnostic yield was 93.5%.No differences were found between pathological diagnosis and frozen pathological diagnosis.The most common lesions were astrocytic lesions,included 16 cases of low-grade glioma and 12 cases of malignant glioma.Remote hemorrhage,metastasis,and lymphoma were following in incidence.Multiple brain lesions were found in 17 cases (27.4%).Eleven cases were frontal lesions (17.7%),8 were frontotemporal (12.9%),6 were frontoparietal (9.7%),and 5 each were temporal,parietal,and parietotemporal lesions (8.1%).Postoperative complications occurred in 21.0% of the patients after biopsies,including 10 haemorrhages (16.1%) and 3 temporary neurological deficits (1 epilepsy,1 headache,and 1 partial hemiparesis).No patient required operation for hematoma evacuation.Conclusion Frameless stereotactic biopsy is an effective and safe technique for histologic diagnosis of brain lesions,particularly for multifocal and frontal lesions.展开更多
Objective To investigate the safety and efficacy of a self-developed novel multi-electrode radiofrequency ablation catheter （Spark） for catheter-based renal denervation （RDN）. Methods A total of 14 experimental mi...Objective To investigate the safety and efficacy of a self-developed novel multi-electrode radiofrequency ablation catheter （Spark） for catheter-based renal denervation （RDN）. Methods A total of 14 experimental miniature pigs were randomly divided into four groups （55°＆ 5-watt, 55°＆ 8-watt, 65°＆ 5-watt, and 65° ＆ 8-watt groups）. Spark was used for left and right renal artery radiofrequency ablation. Blood samples collected from renal arteries and veins as well as renal arteriography were performed on all animals before, immediately after, and three months after procedure to evaluate the effects of Spark on the levels of plasma renin, aldosterone, angiotensin I, and angiotensin II as well as the pathological changes of renal arteries. Results One pig died of an anesthetic accident, 13 pigs successfully underwent the bilateral renal artery ablation. Compared with basic measurements, pigs in all the four groups had significantly decreased mean arterial pres- sure after procedure. Histopathological analysis showed that this procedure could result in intimal hyperplasia, significant peripheral sympa- thetic nerve damage in the renal arteries such as inflammatory cell infiltration and fibrosis in perineurium, uneven distribution of nerve fibers, tissue necrosis, severe vacuolization, fTagmented and unclear nucleoli myelin degeneration, sparse axons, and interruption of continuity. In addition, the renal artery radiofrequency ablation could significantly reduce the levels of plasma renin, aldosterone, angiotensin I, and angio- tensin II in pigs. Conclusions The results suggest that this type of multi-electrode catheter-based radiofrequency ablation could effectively remove peripheral renal sympathetic nerves and reduce the activity of systemic renin-angiotensin system in pigs, thus facilitating the control of systemic blood pressure in pigs.展开更多
Objective To explore the efficacy of hepatic resection(HR) in a relatively unselected group of patients with ovarian cancer liver metastases(OCLM). Methods A study was conducted between September 2000 and September 20...Objective To explore the efficacy of hepatic resection(HR) in a relatively unselected group of patients with ovarian cancer liver metastases(OCLM). Methods A study was conducted between September 2000 and September 2011 on 60 ovarian cancer patients with hepatic metastases(24 solitary and 36 multiple),40 of whom had extrahepatic metastases.HR was done in all patients provided that curative hepatic resection was feasible,and extrahepatic disease was controlled with medical and/or surgical therapy. Results Most patients(n=54;90.0% ) had a negative hepatic margin(R0),whereas 6 patients(10.0% ) had microscopic disease at the margin(R1).The prognostic value of each study variable was assessed using log rank tests for univariate analysis and Cox proportional hazard models for multivariate analysis.The result was a median survival of 39 months and 5-year overall survival rate of 30% .Univariate analysis showed that surgery result(P=0.001),disease free interval(P=0.018) and the number of hepatic lesions (P=0.018) were significantly related to survival.Furthermore,the surgery result(P=0.004) remained significant for prognosis in multivariate analysis. Conclusions For patients with OCLM,HR is safe and may provide a significant survival benefit compared with medical therapy alone.A long interval time,the number of hepatic lesions,and surgery results are key prognostic factors.Favorable outcomes can be achieved even in patients with medically controlled or surgically resectable extrahepatic disease,indicating that surgery should be considered more frequently in the multidisciplinary care of patients with OCLM.展开更多
There are more than eight different design standards in use for the existing railway bridges in China, which have different applicabilities for bridges built in different periods. In this paper, the design load standa...There are more than eight different design standards in use for the existing railway bridges in China, which have different applicabilities for bridges built in different periods. In this paper, the design load standards in different periods are introduced and compared; The working status of the railway is investigated. According to the developing trend of separating passenger and freight transports, by comparing the computed results of the bridge effect and the fatigue cumulative damage, the applicabilities of bearing capacity and fatigue are analyzed for existing bridges. The results indicate that the bearing capacities of 99% existing bridges are suitable for the demand of 26.5 t （axle-weight） freight trains. However, for culverts, bridges with spans less than 20 m, longitudinal and transverse beams of through bridges, suspenders of truss bridges and other locally-stressed members should be evaluated and reinforced due to the increasing axle-weight.展开更多
文摘The use of piezoelectric material sensors in smart composite structures is investigated. An experimental structure bonded with lead zirconate titanate piezoelectric ceramic(PZT) sensors is developed. These bonded sensors are employed to monitor load variations and transient impacts in the structure. Incorporated with pattern recognition approach, PZT sensors have succeeded in detecting the onset and location of damages.
文摘Objective To explore the safety and efficacy of frameless stereotactic brain biopsy.Methods Diagnostic accuracy was calculated by comparing biopsy diagnosis with definitive pathology in 62 patients who underwent frameless stereotactic brain biopsy between January 2008 and December 2010 in Xiamen University Southeast Hospital.Preoperative characteristics and histological diagnosis were reviewed and then information was analysed to identify factors associated with the biopsy not yielding a diagnosis and complications.Results Diagnostic yield was 93.5%.No differences were found between pathological diagnosis and frozen pathological diagnosis.The most common lesions were astrocytic lesions,included 16 cases of low-grade glioma and 12 cases of malignant glioma.Remote hemorrhage,metastasis,and lymphoma were following in incidence.Multiple brain lesions were found in 17 cases (27.4%).Eleven cases were frontal lesions (17.7%),8 were frontotemporal (12.9%),6 were frontoparietal (9.7%),and 5 each were temporal,parietal,and parietotemporal lesions (8.1%).Postoperative complications occurred in 21.0% of the patients after biopsies,including 10 haemorrhages (16.1%) and 3 temporary neurological deficits (1 epilepsy,1 headache,and 1 partial hemiparesis).No patient required operation for hematoma evacuation.Conclusion Frameless stereotactic biopsy is an effective and safe technique for histologic diagnosis of brain lesions,particularly for multifocal and frontal lesions.
文摘Objective To investigate the safety and efficacy of a self-developed novel multi-electrode radiofrequency ablation catheter （Spark） for catheter-based renal denervation （RDN）. Methods A total of 14 experimental miniature pigs were randomly divided into four groups （55°＆ 5-watt, 55°＆ 8-watt, 65°＆ 5-watt, and 65° ＆ 8-watt groups）. Spark was used for left and right renal artery radiofrequency ablation. Blood samples collected from renal arteries and veins as well as renal arteriography were performed on all animals before, immediately after, and three months after procedure to evaluate the effects of Spark on the levels of plasma renin, aldosterone, angiotensin I, and angiotensin II as well as the pathological changes of renal arteries. Results One pig died of an anesthetic accident, 13 pigs successfully underwent the bilateral renal artery ablation. Compared with basic measurements, pigs in all the four groups had significantly decreased mean arterial pres- sure after procedure. Histopathological analysis showed that this procedure could result in intimal hyperplasia, significant peripheral sympa- thetic nerve damage in the renal arteries such as inflammatory cell infiltration and fibrosis in perineurium, uneven distribution of nerve fibers, tissue necrosis, severe vacuolization, fTagmented and unclear nucleoli myelin degeneration, sparse axons, and interruption of continuity. In addition, the renal artery radiofrequency ablation could significantly reduce the levels of plasma renin, aldosterone, angiotensin I, and angio- tensin II in pigs. Conclusions The results suggest that this type of multi-electrode catheter-based radiofrequency ablation could effectively remove peripheral renal sympathetic nerves and reduce the activity of systemic renin-angiotensin system in pigs, thus facilitating the control of systemic blood pressure in pigs.
文摘Objective To explore the efficacy of hepatic resection(HR) in a relatively unselected group of patients with ovarian cancer liver metastases(OCLM). Methods A study was conducted between September 2000 and September 2011 on 60 ovarian cancer patients with hepatic metastases(24 solitary and 36 multiple),40 of whom had extrahepatic metastases.HR was done in all patients provided that curative hepatic resection was feasible,and extrahepatic disease was controlled with medical and/or surgical therapy. Results Most patients(n=54;90.0% ) had a negative hepatic margin(R0),whereas 6 patients(10.0% ) had microscopic disease at the margin(R1).The prognostic value of each study variable was assessed using log rank tests for univariate analysis and Cox proportional hazard models for multivariate analysis.The result was a median survival of 39 months and 5-year overall survival rate of 30% .Univariate analysis showed that surgery result(P=0.001),disease free interval(P=0.018) and the number of hepatic lesions (P=0.018) were significantly related to survival.Furthermore,the surgery result(P=0.004) remained significant for prognosis in multivariate analysis. Conclusions For patients with OCLM,HR is safe and may provide a significant survival benefit compared with medical therapy alone.A long interval time,the number of hepatic lesions,and surgery results are key prognostic factors.Favorable outcomes can be achieved even in patients with medically controlled or surgically resectable extrahepatic disease,indicating that surgery should be considered more frequently in the multidisciplinary care of patients with OCLM.
文摘There are more than eight different design standards in use for the existing railway bridges in China, which have different applicabilities for bridges built in different periods. In this paper, the design load standards in different periods are introduced and compared; The working status of the railway is investigated. According to the developing trend of separating passenger and freight transports, by comparing the computed results of the bridge effect and the fatigue cumulative damage, the applicabilities of bearing capacity and fatigue are analyzed for existing bridges. The results indicate that the bearing capacities of 99% existing bridges are suitable for the demand of 26.5 t （axle-weight） freight trains. However, for culverts, bridges with spans less than 20 m, longitudinal and transverse beams of through bridges, suspenders of truss bridges and other locally-stressed members should be evaluated and reinforced due to the increasing axle-weight.
