Sampling study is an effective exploration method,but the most extreme environments of hydrothermal vents pose considerable engineering challenges for sampling hydrothermal fluids.Moreover,traditional sampler systems ...Sampling study is an effective exploration method,but the most extreme environments of hydrothermal vents pose considerable engineering challenges for sampling hydrothermal fluids.Moreover,traditional sampler systems with sample valves have difficulty in maintaining samples in situ pressure.However,decompression changes have effect on microorganisms sensitive to such stresses.To address the technical difficulty of collecting samples from hydrothermal vents,a new bidirectional high pressure-resistant sample valve with balanced poppet was designed.The sample valve utilizes a soft high performance plastic"PEEK"as poppet.The poppet with inapposite dimension is prone to occur to plastic deformation or rupture for high working pressure in experiments.To address this issue,based on the fmite element model,simulated results on stress distribution of the poppet with different structure parameters and preload spring force were obtained.The static axial deformations on top of the poppet were experimented.The simulated results agree with the experimental results.The new sample valve seals well and it can withstand high working pressure.展开更多
The aim of this paper is to summarize the methods of pancreaticojejunostomy in the pancreatic operation and to study the safety and feasibility of a new operative method called end-to-end invagination pancreaticojejun...The aim of this paper is to summarize the methods of pancreaticojejunostomy in the pancreatic operation and to study the safety and feasibility of a new operative method called end-to-end invagination pancreaticojejunostomy with circle discontinuous U suture to prevent fistula of pancreaticojejunostomy.Eight-three patients with pancreaticoduodenectomy in the 3rd Hospital,Jilin University from 2001 January to 2006 April were reviewed.The incidences of pancreatic fistula with different types of pancreaticojejunostomy were compared.The overall incidence rate of pancreatic fistula was 26.5%(22/83).No pancreatic fistula occurred in end-to-end invagination pancreaticojejunostomy with circle discontinuous U suture.The incidence rate of the fistula following end-to-end invagination pancreaticojejunostomy with circle discontinuous U suture was significantly lower than that of traditional end-to-end pancreaticojejunostomy[40%,(10/25),P<0.01]and end-to-side pancreaticojejunostomy[27.3%,(12/44),P<0.05],but no significant difference(P>0.05)between traditional end-to-end pancreaticojejunostomy and end-to-side pancreaticojejunostomy was discovered.End-to-end invagination pancreaticojejunostomy with circle discontinuous U suture has a definite effect on avoiding pancreatic fistula following pancreaticojejunostomy and is worth being recommended.But the cases were limited,so this method would still need to be observed and confirmed further in the future.展开更多
基金supported by National Hi-tech Research and Development Program of China(863 Program,No.2002AA401002-05).
文摘Sampling study is an effective exploration method,but the most extreme environments of hydrothermal vents pose considerable engineering challenges for sampling hydrothermal fluids.Moreover,traditional sampler systems with sample valves have difficulty in maintaining samples in situ pressure.However,decompression changes have effect on microorganisms sensitive to such stresses.To address the technical difficulty of collecting samples from hydrothermal vents,a new bidirectional high pressure-resistant sample valve with balanced poppet was designed.The sample valve utilizes a soft high performance plastic"PEEK"as poppet.The poppet with inapposite dimension is prone to occur to plastic deformation or rupture for high working pressure in experiments.To address this issue,based on the fmite element model,simulated results on stress distribution of the poppet with different structure parameters and preload spring force were obtained.The static axial deformations on top of the poppet were experimented.The simulated results agree with the experimental results.The new sample valve seals well and it can withstand high working pressure.
文摘The aim of this paper is to summarize the methods of pancreaticojejunostomy in the pancreatic operation and to study the safety and feasibility of a new operative method called end-to-end invagination pancreaticojejunostomy with circle discontinuous U suture to prevent fistula of pancreaticojejunostomy.Eight-three patients with pancreaticoduodenectomy in the 3rd Hospital,Jilin University from 2001 January to 2006 April were reviewed.The incidences of pancreatic fistula with different types of pancreaticojejunostomy were compared.The overall incidence rate of pancreatic fistula was 26.5%(22/83).No pancreatic fistula occurred in end-to-end invagination pancreaticojejunostomy with circle discontinuous U suture.The incidence rate of the fistula following end-to-end invagination pancreaticojejunostomy with circle discontinuous U suture was significantly lower than that of traditional end-to-end pancreaticojejunostomy[40%,(10/25),P<0.01]and end-to-side pancreaticojejunostomy[27.3%,(12/44),P<0.05],but no significant difference(P>0.05)between traditional end-to-end pancreaticojejunostomy and end-to-side pancreaticojejunostomy was discovered.End-to-end invagination pancreaticojejunostomy with circle discontinuous U suture has a definite effect on avoiding pancreatic fistula following pancreaticojejunostomy and is worth being recommended.But the cases were limited,so this method would still need to be observed and confirmed further in the future.
