In this work,we report observations of three comets:38P/Stephan-Oterma,64P/Swift-Gehrels,and C/2017 M4(ATLAS),conducted with the Nanshan one-meter wide-field telescope in 2018 August and November,and 2019January.We ex...In this work,we report observations of three comets:38P/Stephan-Oterma,64P/Swift-Gehrels,and C/2017 M4(ATLAS),conducted with the Nanshan one-meter wide-field telescope in 2018 August and November,and 2019January.We extracted morphological features through image enhancement techniques and calculated the dust activity parameter,Afρ,along with dust mass loss rates and coma color indices using broadband photometric data.Our morphological analysis uncovered a spectrum of dust characteristics among the observed comets,ranging from a significant twisted structure in comet 38P/Stephan-Oterma’s coma to the regular coma envelope surrounding comet 64P/Swift-Gehrels.The Afρvalues varied between 148.8±0.3 cm for 64P/Swift-Gehrels and1118.5±6.2 cm for C/2017 M4(ATLAS)(measured within a reference aperture radius ofρ=6″),indicating a range from moderate to high activity levels.Dust mass loss rates were estimated from 328.1 kg s^(-1)for comet 64P/Swift-Gehrels to 1395.5 kg s^(-1)for comet C/2017 M4(ATLAS).The color indices of comets 38P/Stephan-Oterma and C/2017 M4(ATLAS)closely resemble the average colors of active short-period comets and active longperiod comets,respectively.In contrast,64P/Swift-Gehrels exhibits a significantly bluer hue than typical Jupiter family comets.展开更多
目的探讨氟康唑、伊曲康唑、伏立康唑、酮康唑、特比萘芬、两性霉素B、咪康唑、5-氟胞嘧啶对36株足癣致病菌的体外抑菌特征。方法对55例临床疑似足癣患者行真菌镜检、培养和鉴定。分别应用美国临床实验室标准化委员会(Clinical and Labo...目的探讨氟康唑、伊曲康唑、伏立康唑、酮康唑、特比萘芬、两性霉素B、咪康唑、5-氟胞嘧啶对36株足癣致病菌的体外抑菌特征。方法对55例临床疑似足癣患者行真菌镜检、培养和鉴定。分别应用美国临床实验室标准化委员会(Clinical and Laboratory Standards Institute,CLSI)M38-A2和M27-A3方案针对其中的皮肤癣菌和念珠菌,检测8种药物对不同真菌的最低抑菌浓度(Minimum inhibitory concentration,MIC)。结果镜检及培养均为阳性的真菌36株,计8个菌种:红色毛癣菌、须癣毛癣菌、石膏样小孢子菌、絮状毛癣菌、羊毛状小孢子菌、白念珠菌、光滑念珠菌、克柔念珠菌;属2大类:皮肤癣菌、念珠菌。8种药物对8种真菌的MIC值比较,抑菌效果存在显著差异(P<0.05)。皮肤癣菌和念珠菌2大类比较,除伊曲康唑外(P>0.05),其余7种药物的抑菌效果存在显著差异(P<0.05)。其中,特比萘芬对皮肤癣菌的平均秩次最小。5-氟胞嘧啶对念珠菌的平均秩次最小。结论上述8种药物的体外药敏实验提示,8种药物对8种真菌的抑菌效果存在显著差异。除伊曲康唑外,其余7种药物对皮肤癣菌和念珠菌的抑菌效果存在显著差异。相对而言,特比萘芬对皮肤癣菌抑菌效果更好,5-氟胞嘧啶对念珠菌抑菌效果更好。展开更多
AIM: To determine the role of p38 MAP kinase signal transduction pathways in diallyl disulfide (DADS)-induced G2/M arrest in human gastric cancer MGC803 cells.METHODS: MGC803 cell growth inhibition was measured by MTT...AIM: To determine the role of p38 MAP kinase signal transduction pathways in diallyl disulfide (DADS)-induced G2/M arrest in human gastric cancer MGC803 cells.METHODS: MGC803 cell growth inhibition was measured by MTT assay. Phase distribution of cell cyde was analyzed by flow cytometry. Expression of Cdc25C, p38, phosphorylation of p38 (pp38) were determined by Western blotting.RESULTS: MT1- assay showed that SB203580, a specific p38 MAPK inhibitor blocked DADS-induced growth inhibition.Flow cytometry analysis revealed that treatment of MGC803 cells with 30 mg/L DADS increased the percentage of cells in the G2/M phase from 9.3% to 39.4% (P<0.05), whereas inhibition of p38 activity by SB203580 abolished induction of G2/M arrest by DADS. Western blotting showed that phosphorylation of p38 was increased 3.52-fold following treatment of MGC803 cells with 30 mg/L DADS for 20 min(P<0.05), whereas Cdc25C was decreased 68% following treatment of MGCS03 cells with 30 mg/L DADS for 24 h(P<0.05). Decreased Cdc25C protein expression by DADS was attenuated by SB203580 (P<0.05).CONCLUSION: DADS-induced G2/M arrest of MGC803 cells involves activation of p38 MAP kinase pathways.Decreased Cdc25C protein expression by p38 MAPK played a crucial role in G2/M arrest after treatment with DADS.展开更多
High temperature corrosion properties of M38 alloy with and without 0.04 wt-%Y and 0.05 wt-%Ce additions were studied in equilibrated S0_(2)+0_(2)gas mixtures at 850℃and 900℃.It was found that adding Y or Ce decreas...High temperature corrosion properties of M38 alloy with and without 0.04 wt-%Y and 0.05 wt-%Ce additions were studied in equilibrated S0_(2)+0_(2)gas mixtures at 850℃and 900℃.It was found that adding Y or Ce decreased the corrosion rate of M38 and changed considerably the surface morphologies and composition of corrosion products on M38.The effectiveness of Y and Ce were also discussed.展开更多
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region of China(grant No.2021D01B112)Tianshan Talent Training Program through the grant 2023TSYCCX0101。
文摘In this work,we report observations of three comets:38P/Stephan-Oterma,64P/Swift-Gehrels,and C/2017 M4(ATLAS),conducted with the Nanshan one-meter wide-field telescope in 2018 August and November,and 2019January.We extracted morphological features through image enhancement techniques and calculated the dust activity parameter,Afρ,along with dust mass loss rates and coma color indices using broadband photometric data.Our morphological analysis uncovered a spectrum of dust characteristics among the observed comets,ranging from a significant twisted structure in comet 38P/Stephan-Oterma’s coma to the regular coma envelope surrounding comet 64P/Swift-Gehrels.The Afρvalues varied between 148.8±0.3 cm for 64P/Swift-Gehrels and1118.5±6.2 cm for C/2017 M4(ATLAS)(measured within a reference aperture radius ofρ=6″),indicating a range from moderate to high activity levels.Dust mass loss rates were estimated from 328.1 kg s^(-1)for comet 64P/Swift-Gehrels to 1395.5 kg s^(-1)for comet C/2017 M4(ATLAS).The color indices of comets 38P/Stephan-Oterma and C/2017 M4(ATLAS)closely resemble the average colors of active short-period comets and active longperiod comets,respectively.In contrast,64P/Swift-Gehrels exhibits a significantly bluer hue than typical Jupiter family comets.
基金Supported by the Natural Science Foundation of Hunan Province,No.02JJY2026,01JJY2146 and the Foundation of Hunan ProvinceEducation Department,No.01A016
文摘AIM: To determine the role of p38 MAP kinase signal transduction pathways in diallyl disulfide (DADS)-induced G2/M arrest in human gastric cancer MGC803 cells.METHODS: MGC803 cell growth inhibition was measured by MTT assay. Phase distribution of cell cyde was analyzed by flow cytometry. Expression of Cdc25C, p38, phosphorylation of p38 (pp38) were determined by Western blotting.RESULTS: MT1- assay showed that SB203580, a specific p38 MAPK inhibitor blocked DADS-induced growth inhibition.Flow cytometry analysis revealed that treatment of MGC803 cells with 30 mg/L DADS increased the percentage of cells in the G2/M phase from 9.3% to 39.4% (P<0.05), whereas inhibition of p38 activity by SB203580 abolished induction of G2/M arrest by DADS. Western blotting showed that phosphorylation of p38 was increased 3.52-fold following treatment of MGC803 cells with 30 mg/L DADS for 20 min(P<0.05), whereas Cdc25C was decreased 68% following treatment of MGCS03 cells with 30 mg/L DADS for 24 h(P<0.05). Decreased Cdc25C protein expression by DADS was attenuated by SB203580 (P<0.05).CONCLUSION: DADS-induced G2/M arrest of MGC803 cells involves activation of p38 MAP kinase pathways.Decreased Cdc25C protein expression by p38 MAPK played a crucial role in G2/M arrest after treatment with DADS.
基金supported by the Natural Science Foundation of China。
文摘High temperature corrosion properties of M38 alloy with and without 0.04 wt-%Y and 0.05 wt-%Ce additions were studied in equilibrated S0_(2)+0_(2)gas mixtures at 850℃and 900℃.It was found that adding Y or Ce decreased the corrosion rate of M38 and changed considerably the surface morphologies and composition of corrosion products on M38.The effectiveness of Y and Ce were also discussed.
