Multipass plain strain compression test of 7055 alloy was carried out on Gleeble 1500D thermomechanical simulator to study the effect of interval time on static softening behavior between two passes. Microstructural f...Multipass plain strain compression test of 7055 alloy was carried out on Gleeble 1500D thermomechanical simulator to study the effect of interval time on static softening behavior between two passes. Microstructural features of the alloy deformed with delay times varying from 0 to 180 s after achieving a reduction of ,-~52 % in the 13 stages was investigated through TEM and EBSD observations. The 14th pass of peak stresses after different delay times were gained. The peak stress decreases with the interstage delay time increasing, but the decreasing trend is gradually slower. Static recovery, metadynamic recrystallization, and/or static recrystallization can be found in the alloy during two passes. The recovery and recrystallization degree increases with longer interstage delay time. The static recovery is the main softening mechanism. Subgrain coalescence and subgrain growth together with particle-stimulated nucleation are the main nucleation mechanisms for static recrystallization.展开更多
The aims of this study were to explore whether laparoscopic surgical resections of gastric gastrointestinal stromal tumors （GISTs） would produce better perioperative and similar oncologic outcomes compared with open...The aims of this study were to explore whether laparoscopic surgical resections of gastric gastrointestinal stromal tumors （GISTs） would produce better perioperative and similar oncologic outcomes compared with open surgical resection in Chinese patients. Thirty-six gastric GISTs cases were divided into a minimally invasive laparoscopic group and open resection group, depending on the surgical approach that was used. The general preoperative information, operative time, incision length, intraoperative blood loss, postoperative time to first flatulence, postoperative complications, postoperative hospital stay, total hospitalization costs, and such follow-up data as recurrence, metastasis, and mortality rates were compared between two groups. Among the 36 gastric GISTs, 15 received laparoscopic surgical treatment （laparoscopy group, n=15）, and 21 received routine open resection treatment （open resection group, n=21）. The laparoscopy group and the open resection group showed statistically significant differences （P〈0.05） in incision length （7.8±2.3 vs. 16.9±3.8 cm）, postoperative time to first flatulence （3.8±1.3 vs. 5.1±2.1 d）, postoperative hospitalization time （7.6±2.5 vs. 11.3±3.7 d）, and total cost of hospitalization （RMB 28,239±5,521 vs. RMB 23,761±5,362）. There were no statistically significant differences （P〉0.05） between the laparoscopy group and the open resection group in operative time （147.8±59.3 vs. 139.2±62.1 min） and intraoperative blood loss （149.8±98.9 VS. 154.2±99.3 mL）. Both groups had no postoperative complications, no recurrence and metastasis, and no postoperative mortality. There were no statistically significant differences between the two groups in postoperative complications, postoperative recurrence and metastasis, and postoperative mortality. In conclusion, compared with open resection, the laparoscopic resection of gastric GISTs offers the advantages of less trauma, faster recovery, and shorter hospital stay.展开更多
Objective:To investigate the neuroprotective effect of Phyllanthus urinaria on ischemic stroke and its primary mechanism.Methods:Adult SD rats were selected as the research object,and the right middle cerebral artery ...Objective:To investigate the neuroprotective effect of Phyllanthus urinaria on ischemic stroke and its primary mechanism.Methods:Adult SD rats were selected as the research object,and the right middle cerebral artery infarction rat model was established by the modified suture method(MCAO).Observe the neurological deficit score at 24h,48h and 72h after the model is successfully prepared,then TTC staining method to detect the area of cerebral infarction,the content of superoxide dismutase(SOD),nitric oxide(NO)and endothelial NOS(eNOS)in brain tissue;Immunofluorescence method was used to detect the expression of Caspase-3 positive cells in brain tissue;Western blot method was used to detect the expression of PI3K and AKT protein in brain tissue.72 experimental animals were randomly divided into 4 groups,sham operation group,model group(MCAO),extract of Phyllanthus urinaria low dose group(PuL5 g/kg),high dose group(PuL10 g/kg),and make MCAO model after 7 days of continuous administration,and continue to infuse the medicine once/d until the material is obtained.Results:No neurological deficits in the sham operation group,The 24h,48h and 72h of the modelling showed that the neurological impairment of the two doses of extract of Phyllanthus urinaria and the MCAO group was more severe than that of the sham operation group(P<0.01),however,with the prolongation of the modeling time,the neurological function scores of the two doses of extract of Phyllanthus urinaria were lower than those of the MCAO group,the most significant at 72h(P<0.01);The infarct size of the rats in the two dose groups of extract of Phyllanthus urinaria was lower than that of the MCAO group(P<0.01),and there was no dose dependence between the two groups,the content of SOD in the MCAO group was reduced,and the content of NO and eNOS was increased than the sham operation group(P<0.05),Compared with the MCAO group,the two administration groups significantly increased the content of SOD,decreased the content of NO and eNOS(P<0.05);Although the expression of Caspase-3 positive cells in the two administration groups was higher than that in the sham operation group,it was significantly lower than that in the MCAO group(Plow<0.05,Phigh<0.01);The expression of PI3K and AKT protein in the brain tissue of the MCAO group was significantly lower than that of the sham operation group(P<0.05),but the expression of PI3K and AKT protein in brain tissue of extract of Phyllanthus urinaria in high and low dose groups was significantly higher than that in MCAO group(P<0.05).Conclusion:Extract of Phyllanthus urinaria can improve neurological damage and cerebral infarction area in rats,and reduce the expression of Caspase-3 positive cells in MCAO rats,and then increase the expression levels of PI3K and AKT proteins to protect ischemic brain injury.展开更多
Bridging the gap between the computation of mechanical properties and the chemical structure of elastomers is a long-standing challenge.To fill the gap,we create a raw dataset and build predictive models for Young’s ...Bridging the gap between the computation of mechanical properties and the chemical structure of elastomers is a long-standing challenge.To fill the gap,we create a raw dataset and build predictive models for Young’s modulus,tensile strength,and elongation at break of polyurethane elastomers(PUEs).We then construct a benchmark dataset with 50.4%samples remained from the raw dataset which suffers from the intrinsic diversity problem,through a newly proposed recursive data elimination protocol.The coefficients of determination(R^(2)s)from predictions are improved from 0.73-0.78 to 0.85-0.91 based on the raw and the benchmark datasets.The fitting of stress-strain curves using the machine learning model shows a slightly better performance than that for one of the well-performed constitutive models(e.g.,the Khiêm-Itskov model).It confirmed that the black-box machine learning models are feasible to bridge the gap between the mechanical properties of PUEs and multiple factors for their chemical structures,composition,processing,and measurement settings.While accurate prediction for these curves is still a challenge.We release the raw dataset and the most representative benchmark dataset so far to call for more attention to tackle the longstanding gap problem.展开更多
基金financially supported by the Natural Science Foundation of Inner Mongolia (No. 2011bs0802)Research Fund for the Higher Education of Inner Mongolia (No. NJZY11075)
文摘Multipass plain strain compression test of 7055 alloy was carried out on Gleeble 1500D thermomechanical simulator to study the effect of interval time on static softening behavior between two passes. Microstructural features of the alloy deformed with delay times varying from 0 to 180 s after achieving a reduction of ,-~52 % in the 13 stages was investigated through TEM and EBSD observations. The 14th pass of peak stresses after different delay times were gained. The peak stress decreases with the interstage delay time increasing, but the decreasing trend is gradually slower. Static recovery, metadynamic recrystallization, and/or static recrystallization can be found in the alloy during two passes. The recovery and recrystallization degree increases with longer interstage delay time. The static recovery is the main softening mechanism. Subgrain coalescence and subgrain growth together with particle-stimulated nucleation are the main nucleation mechanisms for static recrystallization.
文摘The aims of this study were to explore whether laparoscopic surgical resections of gastric gastrointestinal stromal tumors （GISTs） would produce better perioperative and similar oncologic outcomes compared with open surgical resection in Chinese patients. Thirty-six gastric GISTs cases were divided into a minimally invasive laparoscopic group and open resection group, depending on the surgical approach that was used. The general preoperative information, operative time, incision length, intraoperative blood loss, postoperative time to first flatulence, postoperative complications, postoperative hospital stay, total hospitalization costs, and such follow-up data as recurrence, metastasis, and mortality rates were compared between two groups. Among the 36 gastric GISTs, 15 received laparoscopic surgical treatment （laparoscopy group, n=15）, and 21 received routine open resection treatment （open resection group, n=21）. The laparoscopy group and the open resection group showed statistically significant differences （P〈0.05） in incision length （7.8±2.3 vs. 16.9±3.8 cm）, postoperative time to first flatulence （3.8±1.3 vs. 5.1±2.1 d）, postoperative hospitalization time （7.6±2.5 vs. 11.3±3.7 d）, and total cost of hospitalization （RMB 28,239±5,521 vs. RMB 23,761±5,362）. There were no statistically significant differences （P〉0.05） between the laparoscopy group and the open resection group in operative time （147.8±59.3 vs. 139.2±62.1 min） and intraoperative blood loss （149.8±98.9 VS. 154.2±99.3 mL）. Both groups had no postoperative complications, no recurrence and metastasis, and no postoperative mortality. There were no statistically significant differences between the two groups in postoperative complications, postoperative recurrence and metastasis, and postoperative mortality. In conclusion, compared with open resection, the laparoscopic resection of gastric GISTs offers the advantages of less trauma, faster recovery, and shorter hospital stay.
基金Natural Science Foundation of Hainan Province(No.817132)。
文摘Objective:To investigate the neuroprotective effect of Phyllanthus urinaria on ischemic stroke and its primary mechanism.Methods:Adult SD rats were selected as the research object,and the right middle cerebral artery infarction rat model was established by the modified suture method(MCAO).Observe the neurological deficit score at 24h,48h and 72h after the model is successfully prepared,then TTC staining method to detect the area of cerebral infarction,the content of superoxide dismutase(SOD),nitric oxide(NO)and endothelial NOS(eNOS)in brain tissue;Immunofluorescence method was used to detect the expression of Caspase-3 positive cells in brain tissue;Western blot method was used to detect the expression of PI3K and AKT protein in brain tissue.72 experimental animals were randomly divided into 4 groups,sham operation group,model group(MCAO),extract of Phyllanthus urinaria low dose group(PuL5 g/kg),high dose group(PuL10 g/kg),and make MCAO model after 7 days of continuous administration,and continue to infuse the medicine once/d until the material is obtained.Results:No neurological deficits in the sham operation group,The 24h,48h and 72h of the modelling showed that the neurological impairment of the two doses of extract of Phyllanthus urinaria and the MCAO group was more severe than that of the sham operation group(P<0.01),however,with the prolongation of the modeling time,the neurological function scores of the two doses of extract of Phyllanthus urinaria were lower than those of the MCAO group,the most significant at 72h(P<0.01);The infarct size of the rats in the two dose groups of extract of Phyllanthus urinaria was lower than that of the MCAO group(P<0.01),and there was no dose dependence between the two groups,the content of SOD in the MCAO group was reduced,and the content of NO and eNOS was increased than the sham operation group(P<0.05),Compared with the MCAO group,the two administration groups significantly increased the content of SOD,decreased the content of NO and eNOS(P<0.05);Although the expression of Caspase-3 positive cells in the two administration groups was higher than that in the sham operation group,it was significantly lower than that in the MCAO group(Plow<0.05,Phigh<0.01);The expression of PI3K and AKT protein in the brain tissue of the MCAO group was significantly lower than that of the sham operation group(P<0.05),but the expression of PI3K and AKT protein in brain tissue of extract of Phyllanthus urinaria in high and low dose groups was significantly higher than that in MCAO group(P<0.05).Conclusion:Extract of Phyllanthus urinaria can improve neurological damage and cerebral infarction area in rats,and reduce the expression of Caspase-3 positive cells in MCAO rats,and then increase the expression levels of PI3K and AKT proteins to protect ischemic brain injury.
基金financially supported by the National Natural Science Foundation of China(Nos.51988102 and 22173094)CAS Key Research Program of Frontier Sciences(No.QYZDYSSW-SLH027)+1 种基金Network and Computing Center,Changchun Institute of Applied Chemistry for essential supportthe financial support of Major Science and Technology Project in Yunnan Province(No.202002AB080001-1)。
文摘Bridging the gap between the computation of mechanical properties and the chemical structure of elastomers is a long-standing challenge.To fill the gap,we create a raw dataset and build predictive models for Young’s modulus,tensile strength,and elongation at break of polyurethane elastomers(PUEs).We then construct a benchmark dataset with 50.4%samples remained from the raw dataset which suffers from the intrinsic diversity problem,through a newly proposed recursive data elimination protocol.The coefficients of determination(R^(2)s)from predictions are improved from 0.73-0.78 to 0.85-0.91 based on the raw and the benchmark datasets.The fitting of stress-strain curves using the machine learning model shows a slightly better performance than that for one of the well-performed constitutive models(e.g.,the Khiêm-Itskov model).It confirmed that the black-box machine learning models are feasible to bridge the gap between the mechanical properties of PUEs and multiple factors for their chemical structures,composition,processing,and measurement settings.While accurate prediction for these curves is still a challenge.We release the raw dataset and the most representative benchmark dataset so far to call for more attention to tackle the longstanding gap problem.
