DMR-249 A is an indigenously developed high strength low alloy steel for Indian ship building industry for making ship-hull and is extensively used in the construction of war ships and submarines. Welding electrodes c...DMR-249 A is an indigenously developed high strength low alloy steel for Indian ship building industry for making ship-hull and is extensively used in the construction of war ships and submarines. Welding electrodes conforming to SFA 5.5 AWS E8018 C1 has been indigenously developed for welding of this steel using shielded metal arc welding process. In the present study, susceptibility to hydrogen assisted cracking of DMR-249 A steel welds made using this electrode has been assessed using implant test. Implant tests were conducted using this electrode at two different levels of diffusible hydrogen, measured using gas chromatography technique. It is observed that both the steel and the welding consumable are not susceptible to hydrogen assisted cracking even with a high diffusible hydrogen level of 9 m L/100 g of weld metal. In implant tests, specimen did not fracture even after loading to stress levels higher than the yield strength of the base metal. The good resistance of this steel and the welding consumable, even with high levels of diffusible hydrogen, is attributed to absence of a susceptible microstructure in both the weld metal and heat affected zone. Hence, this study shows that, in the absence of a susceptible microstructure, hydrogen assisted cracking is unlikely to occur even if hydrogen level is high. It also confirms that in welding of DMR-249 A with indigenously developed E8018 C1 electrode, hydrogen assisted cracking is not a concern and no preheating is required to avoid it during welding.展开更多
Objective: To investigate suitable condition for extraction of the active components from Ajuga nipponensis(A. nipponensis). Methods: Orthogonal experimental design was used to determine the optimal extraction paramet...Objective: To investigate suitable condition for extraction of the active components from Ajuga nipponensis(A. nipponensis). Methods: Orthogonal experimental design was used to determine the optimal extraction parameters for ecdysterones and flavonoids. Finally, the hepatoprotective abilities of A. nipponensis extracts were evaluated by CCl_4-induced animal models. Results:Maximum yields of flavonoids(7.87±0.10) mg/g and ecdysterones(0.73±0.02) mg/g could be obtained when the extraction time was 50 min, the extraction temperature was 60 ℃, and the ratio of sample to 70%(v/v) ethanol was 1:20(w/w). The antioxidant property of A. nipponensis was correlated to the concentration of its extracts. At 5 mg/m L, A. nipponensisextract scavenged 84.8% of DPPH radical and had absorbance values of 2.43±0.04 reducing power. Upon CCl_4-induced liver injury, glutamic oxaloacetic transaminase and glutamic pyruvic transaminase decreased significantly after the mice were treated with A. nipponensis. Histological researches also explained that A. nipponensis reduced the extent of liver lesions induced by CCl_4. Conclusions: A. nipponensis exhibited potent antioxidant activity in chemical experimental models and hepatoprotective effect against CCl_4-induced liver damage.展开更多
The process of selecting an artificial intelligence(AI)model to assist clinical diagnosis of a particular pathology and its validation tests is relevant since the values of accuracy,sensitivity and specificity may not...The process of selecting an artificial intelligence(AI)model to assist clinical diagnosis of a particular pathology and its validation tests is relevant since the values of accuracy,sensitivity and specificity may not reflect the behavior of the method in a real environment.Here,we provide helpful considerations to increase the success of using an AI model in clinical practice.展开更多
AIM: To determine the efficacy of a cap-assisted endoscopy (CAE) to completely visualize the ampulla of Vater (AV) in patients failed by conventional endoscopy. METHODS: A prospective study was conducted on 120 patien...AIM: To determine the efficacy of a cap-assisted endoscopy (CAE) to completely visualize the ampulla of Vater (AV) in patients failed by conventional endoscopy. METHODS: A prospective study was conducted on 120 patients > 20 years of ages who visited the Health Promotion Center of Chungbuk National University Hospital for conscious sedation esophagogastroduodenoscopy (EGD) as a screening test from July to October, 2011. First, forward-viewing endoscopy was performed with reasonable effort using a push and pull method. We considered complete visualization of the AV when we could observe the entire AV including the orifice clearly, and reported the observation as complete or incomplete (partial or not found at all). Second, in cases of complete failure of the observation, an additional AV examination was conducted by attaching a short cap (D-201-10704, Olympus Medical Systems, Tokyo, Japan) to the tip of a forward-viewing endoscope. Third, if the second method failed, we replaced the short cap with a long cap (MH-593, Olympus Medical Systems) and performed a re-examination of the AV. RESULTS: Conventional endoscopy achieved complete visualization of the AV in 97 of the 120 patients (80.8%) but was not achieved in 23 patients (19.2%). Age (mean ± SD) and gender [male (%)] were not significantly different between the complete observation and the incomplete observation groups. Additional short CAE was performed in patients in whom we could not completely visualize the AV. This group included 13 patients (10.9%) with partial observation of the AV and 10 (8.3%) in which the AV was not found. Short CAE permitted a complete observation of the AV in 21 of the 23 patients (91.3%). Patients in whom visualization of the AV failed with short CAE had satisfactory outcomes by replacing the short cap with a long cap. The additional time for CAE took an average of 141 ± 88 s. There were no complications and no significant mucosal trauma. CONCLUSION: CAE is safe to use as a salvage method to achieve complete visualization of the AV when a regular EGD examination fails.展开更多
文摘DMR-249 A is an indigenously developed high strength low alloy steel for Indian ship building industry for making ship-hull and is extensively used in the construction of war ships and submarines. Welding electrodes conforming to SFA 5.5 AWS E8018 C1 has been indigenously developed for welding of this steel using shielded metal arc welding process. In the present study, susceptibility to hydrogen assisted cracking of DMR-249 A steel welds made using this electrode has been assessed using implant test. Implant tests were conducted using this electrode at two different levels of diffusible hydrogen, measured using gas chromatography technique. It is observed that both the steel and the welding consumable are not susceptible to hydrogen assisted cracking even with a high diffusible hydrogen level of 9 m L/100 g of weld metal. In implant tests, specimen did not fracture even after loading to stress levels higher than the yield strength of the base metal. The good resistance of this steel and the welding consumable, even with high levels of diffusible hydrogen, is attributed to absence of a susceptible microstructure in both the weld metal and heat affected zone. Hence, this study shows that, in the absence of a susceptible microstructure, hydrogen assisted cracking is unlikely to occur even if hydrogen level is high. It also confirms that in welding of DMR-249 A with indigenously developed E8018 C1 electrode, hydrogen assisted cracking is not a concern and no preheating is required to avoid it during welding.
基金in part supported by the Forestry Bureau of the Republic of China(Taiwan)(NO.99-06-5-02)
文摘Objective: To investigate suitable condition for extraction of the active components from Ajuga nipponensis(A. nipponensis). Methods: Orthogonal experimental design was used to determine the optimal extraction parameters for ecdysterones and flavonoids. Finally, the hepatoprotective abilities of A. nipponensis extracts were evaluated by CCl_4-induced animal models. Results:Maximum yields of flavonoids(7.87±0.10) mg/g and ecdysterones(0.73±0.02) mg/g could be obtained when the extraction time was 50 min, the extraction temperature was 60 ℃, and the ratio of sample to 70%(v/v) ethanol was 1:20(w/w). The antioxidant property of A. nipponensis was correlated to the concentration of its extracts. At 5 mg/m L, A. nipponensisextract scavenged 84.8% of DPPH radical and had absorbance values of 2.43±0.04 reducing power. Upon CCl_4-induced liver injury, glutamic oxaloacetic transaminase and glutamic pyruvic transaminase decreased significantly after the mice were treated with A. nipponensis. Histological researches also explained that A. nipponensis reduced the extent of liver lesions induced by CCl_4. Conclusions: A. nipponensis exhibited potent antioxidant activity in chemical experimental models and hepatoprotective effect against CCl_4-induced liver damage.
基金Supported by SEDENA Budgetary Program,No.A022-2021.
文摘The process of selecting an artificial intelligence(AI)model to assist clinical diagnosis of a particular pathology and its validation tests is relevant since the values of accuracy,sensitivity and specificity may not reflect the behavior of the method in a real environment.Here,we provide helpful considerations to increase the success of using an AI model in clinical practice.
基金Supported by Grant of the Korea Healthcare Technology R and D Project, Ministry of Health and Welfare, South Korea, No.A100054
文摘AIM: To determine the efficacy of a cap-assisted endoscopy (CAE) to completely visualize the ampulla of Vater (AV) in patients failed by conventional endoscopy. METHODS: A prospective study was conducted on 120 patients > 20 years of ages who visited the Health Promotion Center of Chungbuk National University Hospital for conscious sedation esophagogastroduodenoscopy (EGD) as a screening test from July to October, 2011. First, forward-viewing endoscopy was performed with reasonable effort using a push and pull method. We considered complete visualization of the AV when we could observe the entire AV including the orifice clearly, and reported the observation as complete or incomplete (partial or not found at all). Second, in cases of complete failure of the observation, an additional AV examination was conducted by attaching a short cap (D-201-10704, Olympus Medical Systems, Tokyo, Japan) to the tip of a forward-viewing endoscope. Third, if the second method failed, we replaced the short cap with a long cap (MH-593, Olympus Medical Systems) and performed a re-examination of the AV. RESULTS: Conventional endoscopy achieved complete visualization of the AV in 97 of the 120 patients (80.8%) but was not achieved in 23 patients (19.2%). Age (mean ± SD) and gender [male (%)] were not significantly different between the complete observation and the incomplete observation groups. Additional short CAE was performed in patients in whom we could not completely visualize the AV. This group included 13 patients (10.9%) with partial observation of the AV and 10 (8.3%) in which the AV was not found. Short CAE permitted a complete observation of the AV in 21 of the 23 patients (91.3%). Patients in whom visualization of the AV failed with short CAE had satisfactory outcomes by replacing the short cap with a long cap. The additional time for CAE took an average of 141 ± 88 s. There were no complications and no significant mucosal trauma. CONCLUSION: CAE is safe to use as a salvage method to achieve complete visualization of the AV when a regular EGD examination fails.
