AIM:To assess the value of a new test for the diagnosis of Helicobacter pylori(H.pylori) infection,Rapirun H.pylori Antibody Stick(Rapirun Stick),in a Vietnamese population.METHODS:Eligible patients without previo...AIM:To assess the value of a new test for the diagnosis of Helicobacter pylori(H.pylori) infection,Rapirun H.pylori Antibody Stick(Rapirun Stick),in a Vietnamese population.METHODS:Eligible patients without previous history of H.pylori eradication were recruited.Rapid urease test(RUT) and histologic examination were used to diagnose the H.pylori infection.Patients were considered H.pylori positive when the RUT results were positive and/or the bacteria were detected histologically.Rapirun Stick tests were performed using urine samples,and the results were compared with the other 2 methods.RESULTS:We enrolled 200 patients with a mean age of 36(range,18-76) years.There were 116 females and 84 males.Of the 200 patients,111(55.5%) were diagnosed as being H.pylori positive.The sensitivity,specificity,and accuracy of the Stick test were 84.7%,89.9%,and 87.0%,respectively.There were 17(8.5%) falsenegative patients and 9(4.5%) false-positive patients.CONCLUSION:The Rapirun Stick test has high sensitivity,specificity,and accuracy for the diagnosis of H.pylori infection in the Vietnamese population.The test can be clinically applied in Vietnamese populations.展开更多
In this paper,compression tests of intact granite samples have been made in a triaxial testing machine with solid confining pressure.From the tests,the influences of confining pressure and loading rate(axial strain ra...In this paper,compression tests of intact granite samples have been made in a triaxial testing machine with solid confining pressure.From the tests,the influences of confining pressure and loading rate(axial strain rate)on the deformation and fracture process of rock samples,on the stress drop and recurrence interval of stick-slip events,and on the geometric distribution of the main fracture have been studied.The experimental results show that the loading rate influences the stress drop and recurrence interval of stick-slip events greatly.At lower loading rates,the stress drop of stick-slip events is greater,their recurrence interval is longer and shows no regularity in distribution.When the loading rate goes higher,the stress drop will become smaller and the recurrence interval will tend to be constant and stick-slip events show a quasi-periodicity.At lower confining pressures and strain rates,the main fracture may evolve into 2 X-shaped conjugate shear faults; whereas at higher confining pressures展开更多
In drilling field, stick-slip vibrations of the drill-string are the main reason for the failure of the drilling system. To suppress the undesired stick-slip vibrations, an observer-based state feedback control method...In drilling field, stick-slip vibrations of the drill-string are the main reason for the failure of the drilling system. To suppress the undesired stick-slip vibrations, an observer-based state feedback control method is proposed. The drilling system is described by a lumped parameter model including a Karnopp friction torque model. A state observer is designed to estimate the bit velocity in bottom hole and a state feedback controller is proposed to control the top drive velocity. By simulation, the performance of the control algorithm is demonstrated. Based on the control algorithm, a stick-slip vibration control system is developed. Test results show that the control system can effectively eliminate stick-slip vibrations of the drill-string and can be applied to the drilling field.展开更多
Jurassic weak & non-stick coal in Hengshan of North Shaanxi Province was pretreated by the nitric acid.Then,it was biodegraded by Phanerochaete chrysosporium. The biodegradation role of the white-rot fungus for co...Jurassic weak & non-stick coal in Hengshan of North Shaanxi Province was pretreated by the nitric acid.Then,it was biodegraded by Phanerochaete chrysosporium. The biodegradation role of the white-rot fungus for coal is extremely significant.Orthogo- nal test demonstrate that liquefied time,liquefaction temperature and the amount of fun- gus liquids etc.are the main factors affecting the coal biodegradation rate.The best tech- nical condition of the coal biological liquefaction was got.Comparing the coal sample be- fore biodegradation with that after biodegradation,it is found that the ash of the coal resi- due after biodegradation reduces significantly,H and O contents increase,C and N con- tents decrease.The biodegradation change the coal macromolecular structure.展开更多
基金Supported by International Collaborative Research Grant of the Japanese Society of Gastrointestinal Cancer Screening
文摘AIM:To assess the value of a new test for the diagnosis of Helicobacter pylori(H.pylori) infection,Rapirun H.pylori Antibody Stick(Rapirun Stick),in a Vietnamese population.METHODS:Eligible patients without previous history of H.pylori eradication were recruited.Rapid urease test(RUT) and histologic examination were used to diagnose the H.pylori infection.Patients were considered H.pylori positive when the RUT results were positive and/or the bacteria were detected histologically.Rapirun Stick tests were performed using urine samples,and the results were compared with the other 2 methods.RESULTS:We enrolled 200 patients with a mean age of 36(range,18-76) years.There were 116 females and 84 males.Of the 200 patients,111(55.5%) were diagnosed as being H.pylori positive.The sensitivity,specificity,and accuracy of the Stick test were 84.7%,89.9%,and 87.0%,respectively.There were 17(8.5%) falsenegative patients and 9(4.5%) false-positive patients.CONCLUSION:The Rapirun Stick test has high sensitivity,specificity,and accuracy for the diagnosis of H.pylori infection in the Vietnamese population.The test can be clinically applied in Vietnamese populations.
文摘In this paper,compression tests of intact granite samples have been made in a triaxial testing machine with solid confining pressure.From the tests,the influences of confining pressure and loading rate(axial strain rate)on the deformation and fracture process of rock samples,on the stress drop and recurrence interval of stick-slip events,and on the geometric distribution of the main fracture have been studied.The experimental results show that the loading rate influences the stress drop and recurrence interval of stick-slip events greatly.At lower loading rates,the stress drop of stick-slip events is greater,their recurrence interval is longer and shows no regularity in distribution.When the loading rate goes higher,the stress drop will become smaller and the recurrence interval will tend to be constant and stick-slip events show a quasi-periodicity.At lower confining pressures and strain rates,the main fracture may evolve into 2 X-shaped conjugate shear faults; whereas at higher confining pressures
文摘In drilling field, stick-slip vibrations of the drill-string are the main reason for the failure of the drilling system. To suppress the undesired stick-slip vibrations, an observer-based state feedback control method is proposed. The drilling system is described by a lumped parameter model including a Karnopp friction torque model. A state observer is designed to estimate the bit velocity in bottom hole and a state feedback controller is proposed to control the top drive velocity. By simulation, the performance of the control algorithm is demonstrated. Based on the control algorithm, a stick-slip vibration control system is developed. Test results show that the control system can effectively eliminate stick-slip vibrations of the drill-string and can be applied to the drilling field.
基金the National Natural Science Foundation of China(40772103)
文摘Jurassic weak & non-stick coal in Hengshan of North Shaanxi Province was pretreated by the nitric acid.Then,it was biodegraded by Phanerochaete chrysosporium. The biodegradation role of the white-rot fungus for coal is extremely significant.Orthogo- nal test demonstrate that liquefied time,liquefaction temperature and the amount of fun- gus liquids etc.are the main factors affecting the coal biodegradation rate.The best tech- nical condition of the coal biological liquefaction was got.Comparing the coal sample be- fore biodegradation with that after biodegradation,it is found that the ash of the coal resi- due after biodegradation reduces significantly,H and O contents increase,C and N con- tents decrease.The biodegradation change the coal macromolecular structure.
