BACKGROUND Neurological complications are common in the management of venoarterial extracorporeal membrane oxygenation(VA-ECMO),with most patients requiring sedation and intubation,limiting the assessment of neurologi...BACKGROUND Neurological complications are common in the management of venoarterial extracorporeal membrane oxygenation(VA-ECMO),with most patients requiring sedation and intubation,limiting the assessment of neurological function.Therefore,we must rely on advanced neuroimaging techniques,such as computed tomography angiography(CTA)and computed tomography perfusion(CTP).Because ECMO changes the normal blood flow pattern,it may interfere with the contrast medium in some special cases,leading to artifacts and ultimately misleading clinical decisions.CASE SUMMARY A 61-year-old man presented to a local hospital with chest tightness and pain 1 d prior to presentation.The patient was treated with VA-ECMO after sudden cardiac and respiratory arrest at a local hospital.For further treatment,the patient was transferred to our hospital.The initial consciousness assessment was not clear,and routine CTP was performed to understand the intracranial changes,which suggested a large area of cerebral infarction on the right side;however,the cerebral oxygen was not consistent with the CTP results,and the reexamination of CTA still suggested a right cerebral infarction.To identify this difference,bedside transcranial Doppler was performed,and the blood flow on both sides was different.By reducing the ECMO flow,CTP reexamination showed that the results were normal and consistent with the clinical results.On day 3,the patient was alert and showed good limb movements.CONCLUSION In patients with peripheral VA-ECMO,cerebral perfusion confirmed by CTP and CTA may lead to false cerebral infarction.展开更多
A new membrane finite element method for modeling fluid flow in a porous medium is presented in order to quickly and accurately simulate the geo-membrane fabric used in civil engineering. It is based on discontinuous ...A new membrane finite element method for modeling fluid flow in a porous medium is presented in order to quickly and accurately simulate the geo-membrane fabric used in civil engineering. It is based on discontinuous finite element theory, and can be easily coupled with the normal Galerkin finite element method. Based on the saturated seepage equation, the element coefficient matrix of the membrane element method is derived, and a geometric transform relation for the membrane element between a global coordinate system and a local coordinate system is obtained. A method for the determination of the fluid flux conductivity of the membrane element is presented. This method provides a basis for determining discontinuous parameters in discontinuous finite element theory. An anti-seepage problem regarding the foundation of a building is analyzed by coupling the membrane finite element method with the normal Galerkin finite element method. The analysis results demonstrate the utility and superiority of the membrane finite element method in fluid flow analysis of a porous medium.展开更多
Members of the Pseudomonas family are commonly found in nature, some species are pathogenic for humans, as well as being resistant to multiple disinfectants. Various studies have revealed that benzalkonium chloride (B...Members of the Pseudomonas family are commonly found in nature, some species are pathogenic for humans, as well as being resistant to multiple disinfectants. Various studies have revealed that benzalkonium chloride (BKC) has an inhibitory effect on many bacteria but it has no significant effect on Pseudomonas aeruginosa. Cetrimide agar medium is recommended for the isolation and enumeration of Ps. aeruginosa in food and environmental samples. However, there are claims that for some food factories and in particular the bottled water industry, the selectivity of this medium is not sufficient. The aim of the current research is the creation of a more selective medium for Ps. aeruginosa with BKC. A total of 28 isolates were isolated with Cetrimide agar from raw water samples and identified using biochemical tests and commercial identification kits. All the bacteria were inoculated in Cetrimide agar plates containing 0 - 625 μg/mL BKC. The Petri dishes were incubated at 37°C and 42°C for 24 h. The results showed that 375 μg/mL BKC was sufficient to suppress Burk. pseudomallei at both incubation temperatures. Ps. fluorescens-35 could not grow at 42°C at any concentration, including the control, and was suppressed at 500 μg/mL BKC. All the Ps. aeruginosa isolates and control strain were grown at both incubation temperatures at 375 μg/mL BKC concentration. In conclusion, the analysis of Ps. aeruginosa showed that the growth of accompanying flora may be suppressed by adding 375-μg/mL BKC into Cetrimide agar and incubating at an elevated temperature of 42°C.展开更多
文摘BACKGROUND Neurological complications are common in the management of venoarterial extracorporeal membrane oxygenation(VA-ECMO),with most patients requiring sedation and intubation,limiting the assessment of neurological function.Therefore,we must rely on advanced neuroimaging techniques,such as computed tomography angiography(CTA)and computed tomography perfusion(CTP).Because ECMO changes the normal blood flow pattern,it may interfere with the contrast medium in some special cases,leading to artifacts and ultimately misleading clinical decisions.CASE SUMMARY A 61-year-old man presented to a local hospital with chest tightness and pain 1 d prior to presentation.The patient was treated with VA-ECMO after sudden cardiac and respiratory arrest at a local hospital.For further treatment,the patient was transferred to our hospital.The initial consciousness assessment was not clear,and routine CTP was performed to understand the intracranial changes,which suggested a large area of cerebral infarction on the right side;however,the cerebral oxygen was not consistent with the CTP results,and the reexamination of CTA still suggested a right cerebral infarction.To identify this difference,bedside transcranial Doppler was performed,and the blood flow on both sides was different.By reducing the ECMO flow,CTP reexamination showed that the results were normal and consistent with the clinical results.On day 3,the patient was alert and showed good limb movements.CONCLUSION In patients with peripheral VA-ECMO,cerebral perfusion confirmed by CTP and CTA may lead to false cerebral infarction.
基金supported by the National Natural Science Foundation of China (Grant No. 50779012)
文摘A new membrane finite element method for modeling fluid flow in a porous medium is presented in order to quickly and accurately simulate the geo-membrane fabric used in civil engineering. It is based on discontinuous finite element theory, and can be easily coupled with the normal Galerkin finite element method. Based on the saturated seepage equation, the element coefficient matrix of the membrane element method is derived, and a geometric transform relation for the membrane element between a global coordinate system and a local coordinate system is obtained. A method for the determination of the fluid flux conductivity of the membrane element is presented. This method provides a basis for determining discontinuous parameters in discontinuous finite element theory. An anti-seepage problem regarding the foundation of a building is analyzed by coupling the membrane finite element method with the normal Galerkin finite element method. The analysis results demonstrate the utility and superiority of the membrane finite element method in fluid flow analysis of a porous medium.
文摘Members of the Pseudomonas family are commonly found in nature, some species are pathogenic for humans, as well as being resistant to multiple disinfectants. Various studies have revealed that benzalkonium chloride (BKC) has an inhibitory effect on many bacteria but it has no significant effect on Pseudomonas aeruginosa. Cetrimide agar medium is recommended for the isolation and enumeration of Ps. aeruginosa in food and environmental samples. However, there are claims that for some food factories and in particular the bottled water industry, the selectivity of this medium is not sufficient. The aim of the current research is the creation of a more selective medium for Ps. aeruginosa with BKC. A total of 28 isolates were isolated with Cetrimide agar from raw water samples and identified using biochemical tests and commercial identification kits. All the bacteria were inoculated in Cetrimide agar plates containing 0 - 625 μg/mL BKC. The Petri dishes were incubated at 37°C and 42°C for 24 h. The results showed that 375 μg/mL BKC was sufficient to suppress Burk. pseudomallei at both incubation temperatures. Ps. fluorescens-35 could not grow at 42°C at any concentration, including the control, and was suppressed at 500 μg/mL BKC. All the Ps. aeruginosa isolates and control strain were grown at both incubation temperatures at 375 μg/mL BKC concentration. In conclusion, the analysis of Ps. aeruginosa showed that the growth of accompanying flora may be suppressed by adding 375-μg/mL BKC into Cetrimide agar and incubating at an elevated temperature of 42°C.
