BACKGROUND Uncovered stents used for malignant obstructions in the biliary tree, especially in the hilar area, are prone to obstruction by tumor ingrowths. In comparison, however, covered stents may block bile duct br...BACKGROUND Uncovered stents used for malignant obstructions in the biliary tree, especially in the hilar area, are prone to obstruction by tumor ingrowths. In comparison, however, covered stents may block bile duct branches and are at risk of migration. We have developed a multi-hole self-expandable metallic stent (MHSEMS), with a hole in each cell, to prevent the obstruction of bile duct branches. In addition, the holes may prevent migration due to small ingrowths by reducing the tension of the membrane. CASE SUMMARY MHSEMS were placed in five patients with a malignant obstruction and one with post-endoscopic sphincterotomy bleeding. Each MHSEMS was successfully deployed in all cases. Patients showed no complications. Two cases were reviewed. Case 1: A 74-year-old male presented with jaundice and was diagnosed with a sigmoid colon cancer and giant liver metastases in the right liver lobe. A MHSEMS was placed in the left bile duct. The jaundice improved and peroral cholangioscopy was performed. Case 2: A 90-year-old female was admitted to hospital for jaundice and diagnosed with cholangiocarcinoma. A MHSEMS was placed in the left bile duct but after 8 months the stent became obstructed by tumor ingrowth. We treated the patient by ablation therapy. A silicone cover separated the internal bile duct from the surrounding tissue, protecting the latter from thermal injury during treatment by endobiliary ablation of the reobstruction. CONCLUSION A MHSEMS is a new choice of stent for biliary tract diseases.展开更多
As demonstrated by former work,the holed casing treatment can be used to expand the stall margin of a centrifugal compressor with unshrouded impeller.In addition,the choked margin can also be expanded as experimental ...As demonstrated by former work,the holed casing treatment can be used to expand the stall margin of a centrifugal compressor with unshrouded impeller.In addition,the choked margin can also be expanded as experimental results indicated.Moreover,the compressor performance,especially the efficiency,on the whole working range is improved.As shown by experiments,the stall margin and choked margin of the compressor are extended,and the maximum efficiency improvement is 14%at the large flowrate of 1.386.Numerical simulations were carried out to analyze the flow in the impeller and in the holes in the case of large flowrate.The results indicate that in large flowrate conditions,there is a low-pressure region on the throat part of the impeller passage,leading to the bypass flows appearing in the holes,which means the flow area at the inlet of the impeller is increased.The bypass flow can also contribute to the decrease of the Mach number at the throat part near the shroud end-wall which implies that the choked margin is expanded.Besides,as the bypass flow would inhibit the development of the vertexes in the tip clearance and suppress the flow recirculation in the shroud end-wall region,both the pressure ratio and efficiency of the compressor are improved,which agrees well with the experiments.展开更多
We carried out experiments with various concentrations of Trichoderma harzianum YC459 in different soil types(forest soil, mixed soil,merchantable soil, and leaf mold soil) to evaluate its effect on seed germination a...We carried out experiments with various concentrations of Trichoderma harzianum YC459 in different soil types(forest soil, mixed soil,merchantable soil, and leaf mold soil) to evaluate its effect on seed germination and seedling establishment of four species(Festuca arundinacea Schreb., Dianthus barbatus var. asiaticus Nakai,Lespedeza cyrtobotrya Miq., and Parthenocissus tricuspidata Planch) for rock slope restoration. We also investigated the use of drilled slanted holes on the rock slopes for seedling establishment. The results showed that T. harzianum concentration had significant effects on seed germination, seedling growth, and seedling survival for all the species with different soil types. Seed germination and survival rates peaked at 5% T. harzianum concentration with leaf mold soil and decreased as T. harzianum concentration increased from 5% to 10%. Seedling survival rates of all four species were generally lowest at 0% T. harzianum concentration in all soil types.The height of F. arundinacea and L. cyrtobotrya peaked at 5% T. harzianum concentration whereas that of D. barbatus and P. tricuspidata peaked at 10%T. harzianum concentration. We concluded that 5% T. harzianum concentration with leaf mold soil is appropriate for seed germination and seedling survival rates of most species, thus enhancing seedling establishment. Practical application of the findings of this study will contribute in the vegetation restoration of steep rocks in mountain environments.展开更多
BACKGROUND Myopic foveoschisis(MF)is a common complication of pathological myopia.A macular hole(MH)usually results from the natural progression of MF and is a common complication of vitrectomy.Vitrectomy combined wit...BACKGROUND Myopic foveoschisis(MF)is a common complication of pathological myopia.A macular hole(MH)usually results from the natural progression of MF and is a common complication of vitrectomy.Vitrectomy combined with residual internal limiting membrane(ILM)covering and autologous blood was effective for closing a secondary MH.CASE SUMMARY A 52-year-old woman presented to our clinic with a complaint of blurred vision in the right eye for 7 years.Her best corrected visual acuity(BCVA)was 20/100,axial length was 25.79 mm and standard equivalent refractive error was-10.5 dioptres.Preoperative optical coherence tomography revealed foveoschisis in the right eye.Vitrectomy with fovea-sparing ILM peeling was performed.An MH developed and gradually expanded 5 mo after the initial vitrectomy.Vitrectomy with residual ILM covering and autologous blood was performed.The MH closed 3 wk after the second vitrectomy.CONCLUSION Fovea-sparing ILM peeling can provide residual ILM for the treatment of MH secondary to vitrectomy for MF.Vitrectomy combined with residual ILM covering and autologous blood is effective for closing secondary MH and improving BCVA.展开更多
The study of the thin bed responses and correction methods in cased hole density logging can provide a theoretical basis for research to improve data processing methods. By using the Monte Carlo program MCNP, the chan...The study of the thin bed responses and correction methods in cased hole density logging can provide a theoretical basis for research to improve data processing methods. By using the Monte Carlo program MCNP, the change of detector count from thin beds with the vertical depth was calculated at different casing thicknesses. The calculation showed that with the low density thin bed moving upward, detector count first increased to a maximum then decreased. The responses of a thin bed with a high density were opposite to those of a thin bed with a low density. The change curve was symmetrical, and the maximums or minimums appeared at the midpoint between the detector and source. Besides, detector count increased with increasing thin bed thickness. At a specific thin bed thickness, further increase of thin bed thickness resulted in a slow increase of detector count then the count rate leveled off. In actual logging, the influence of adjacent formations on density log measurements can be ignored. Finally, based on numerical simulation correction methods for the dual influence of casing and thin beds are discussed.展开更多
BACKGROUND Phakic intraocular lens(pIOL)implantation has been commonly prescribed and is considered as a safe and effective option for correcting high myopia.However,it is associated with multiple complications.CASE S...BACKGROUND Phakic intraocular lens(pIOL)implantation has been commonly prescribed and is considered as a safe and effective option for correcting high myopia.However,it is associated with multiple complications.CASE SUMMARY This report describes a case of full-thickness macular hole(MH)in a patient with a history of bilateral pIOL implantation for the correction of myopia of–12.00 diopters in both eyes 7 mo ago.The MH closed after pars plana vitrectomy with internal limiting membrane removal and the best-corrected visual acuity improved to 20/40 in the left eye.CONCLUSION In rare cases,MH can occur following pIOL.In this present case report,we analyzed the formation process of MH following the surgery and emphasized that it is important to inform highly myopic patients about the risk of MH occurrence while being aware of the symptoms of this complication.展开更多
文摘BACKGROUND Uncovered stents used for malignant obstructions in the biliary tree, especially in the hilar area, are prone to obstruction by tumor ingrowths. In comparison, however, covered stents may block bile duct branches and are at risk of migration. We have developed a multi-hole self-expandable metallic stent (MHSEMS), with a hole in each cell, to prevent the obstruction of bile duct branches. In addition, the holes may prevent migration due to small ingrowths by reducing the tension of the membrane. CASE SUMMARY MHSEMS were placed in five patients with a malignant obstruction and one with post-endoscopic sphincterotomy bleeding. Each MHSEMS was successfully deployed in all cases. Patients showed no complications. Two cases were reviewed. Case 1: A 74-year-old male presented with jaundice and was diagnosed with a sigmoid colon cancer and giant liver metastases in the right liver lobe. A MHSEMS was placed in the left bile duct. The jaundice improved and peroral cholangioscopy was performed. Case 2: A 90-year-old female was admitted to hospital for jaundice and diagnosed with cholangiocarcinoma. A MHSEMS was placed in the left bile duct but after 8 months the stent became obstructed by tumor ingrowth. We treated the patient by ablation therapy. A silicone cover separated the internal bile duct from the surrounding tissue, protecting the latter from thermal injury during treatment by endobiliary ablation of the reobstruction. CONCLUSION A MHSEMS is a new choice of stent for biliary tract diseases.
基金supported by the National Natural Science Foundation of China(Grant No.50776056)the High Technology Research and Development Program of China("863"Program)(Grant No. 2009AA05Z201)
文摘As demonstrated by former work,the holed casing treatment can be used to expand the stall margin of a centrifugal compressor with unshrouded impeller.In addition,the choked margin can also be expanded as experimental results indicated.Moreover,the compressor performance,especially the efficiency,on the whole working range is improved.As shown by experiments,the stall margin and choked margin of the compressor are extended,and the maximum efficiency improvement is 14%at the large flowrate of 1.386.Numerical simulations were carried out to analyze the flow in the impeller and in the holes in the case of large flowrate.The results indicate that in large flowrate conditions,there is a low-pressure region on the throat part of the impeller passage,leading to the bypass flows appearing in the holes,which means the flow area at the inlet of the impeller is increased.The bypass flow can also contribute to the decrease of the Mach number at the throat part near the shroud end-wall which implies that the choked margin is expanded.Besides,as the bypass flow would inhibit the development of the vertexes in the tip clearance and suppress the flow recirculation in the shroud end-wall region,both the pressure ratio and efficiency of the compressor are improved,which agrees well with the experiments.
基金the support of "Forest Science & Technology Projects (Project No. S211216L020110)" provided by Korea Forest Service
文摘We carried out experiments with various concentrations of Trichoderma harzianum YC459 in different soil types(forest soil, mixed soil,merchantable soil, and leaf mold soil) to evaluate its effect on seed germination and seedling establishment of four species(Festuca arundinacea Schreb., Dianthus barbatus var. asiaticus Nakai,Lespedeza cyrtobotrya Miq., and Parthenocissus tricuspidata Planch) for rock slope restoration. We also investigated the use of drilled slanted holes on the rock slopes for seedling establishment. The results showed that T. harzianum concentration had significant effects on seed germination, seedling growth, and seedling survival for all the species with different soil types. Seed germination and survival rates peaked at 5% T. harzianum concentration with leaf mold soil and decreased as T. harzianum concentration increased from 5% to 10%. Seedling survival rates of all four species were generally lowest at 0% T. harzianum concentration in all soil types.The height of F. arundinacea and L. cyrtobotrya peaked at 5% T. harzianum concentration whereas that of D. barbatus and P. tricuspidata peaked at 10%T. harzianum concentration. We concluded that 5% T. harzianum concentration with leaf mold soil is appropriate for seed germination and seedling survival rates of most species, thus enhancing seedling establishment. Practical application of the findings of this study will contribute in the vegetation restoration of steep rocks in mountain environments.
文摘BACKGROUND Myopic foveoschisis(MF)is a common complication of pathological myopia.A macular hole(MH)usually results from the natural progression of MF and is a common complication of vitrectomy.Vitrectomy combined with residual internal limiting membrane(ILM)covering and autologous blood was effective for closing a secondary MH.CASE SUMMARY A 52-year-old woman presented to our clinic with a complaint of blurred vision in the right eye for 7 years.Her best corrected visual acuity(BCVA)was 20/100,axial length was 25.79 mm and standard equivalent refractive error was-10.5 dioptres.Preoperative optical coherence tomography revealed foveoschisis in the right eye.Vitrectomy with fovea-sparing ILM peeling was performed.An MH developed and gradually expanded 5 mo after the initial vitrectomy.Vitrectomy with residual ILM covering and autologous blood was performed.The MH closed 3 wk after the second vitrectomy.CONCLUSION Fovea-sparing ILM peeling can provide residual ILM for the treatment of MH secondary to vitrectomy for MF.Vitrectomy combined with residual ILM covering and autologous blood is effective for closing secondary MH and improving BCVA.
文摘The study of the thin bed responses and correction methods in cased hole density logging can provide a theoretical basis for research to improve data processing methods. By using the Monte Carlo program MCNP, the change of detector count from thin beds with the vertical depth was calculated at different casing thicknesses. The calculation showed that with the low density thin bed moving upward, detector count first increased to a maximum then decreased. The responses of a thin bed with a high density were opposite to those of a thin bed with a low density. The change curve was symmetrical, and the maximums or minimums appeared at the midpoint between the detector and source. Besides, detector count increased with increasing thin bed thickness. At a specific thin bed thickness, further increase of thin bed thickness resulted in a slow increase of detector count then the count rate leveled off. In actual logging, the influence of adjacent formations on density log measurements can be ignored. Finally, based on numerical simulation correction methods for the dual influence of casing and thin beds are discussed.
文摘BACKGROUND Phakic intraocular lens(pIOL)implantation has been commonly prescribed and is considered as a safe and effective option for correcting high myopia.However,it is associated with multiple complications.CASE SUMMARY This report describes a case of full-thickness macular hole(MH)in a patient with a history of bilateral pIOL implantation for the correction of myopia of–12.00 diopters in both eyes 7 mo ago.The MH closed after pars plana vitrectomy with internal limiting membrane removal and the best-corrected visual acuity improved to 20/40 in the left eye.CONCLUSION In rare cases,MH can occur following pIOL.In this present case report,we analyzed the formation process of MH following the surgery and emphasized that it is important to inform highly myopic patients about the risk of MH occurrence while being aware of the symptoms of this complication.
