The events of cell death and the expression of nuclear matrix protein (NMP) have been investigated in a promyelocytic leukemic cell line HL-60 induced with etoposide. By means of TUNEL assay, the nuclei displayed a ch...The events of cell death and the expression of nuclear matrix protein (NMP) have been investigated in a promyelocytic leukemic cell line HL-60 induced with etoposide. By means of TUNEL assay, the nuclei displayed a characteristic morphology change, and the amount of apoptotic cells increased early and reached maximun about 39% after treatment with etoposide for 2 h. Nucleosomal DNA fragmentation was observed after treatment for 4 h. The morphological change of HL-60 cells, thus, occurred earlier than the appearance of DNA ladder. Total nuclear matrix proteins were analyzed by 2-dimensional gel electrophoresis. Differential expression of 59 nuclear matrix proteins was found in 4 h etoposide treated cells. Western blotting was then performed on three nuclear matrix acssociated proteins, PML, HSC70 and NuMA. The expression of the suppressor PML protein and heat shock protein HSC70 were significantly upregulated after etoposide treatment, while NuMA, a nuclear mitotic apparatus protein, was down regulated. These results demonstrate that significant biochemical alterations in nuclear matrix proteins take place during the apoptotic process.展开更多
In order to study the effect of continuous casting process parameters on the shape of slab solidification end under non-uniform cooling,a solidification model of a continuous-cast slab with non-uniform cooling conditi...In order to study the effect of continuous casting process parameters on the shape of slab solidification end under non-uniform cooling,a solidification model of a continuous-cast slab with non-uniform cooling condition was established with ProCAST software.The model was verified by the results of nail shooting tests and the infrared temperature measurement equipment.Four characteristic parameters were defined to evaluate the uniformity of the shape of slab solidification end.The results showed that the nonuniformity at the beginning and end of solidification,the solidification end length,and the solidification unevenness increased with the rise of casting speed.For each 10°C increase of superheat,the solidification unevenness increased by about 0.022.However,the effect of superheat on the solidification end length can be ignored.The secondary cooling strength showed minimal effect on the nonuniformity at the beginning and end of solidification.With the increase in secondary cooling intensity,the solidification end length decreased,but the solidification unevenness increased.In addition,the central segregation of the slab produced with and without the mechanical soft reduction(MSR)process was investigated.The transverse flow of molten steel with low solid fraction influenced the central segregation morphology under MSR.展开更多
文摘The events of cell death and the expression of nuclear matrix protein (NMP) have been investigated in a promyelocytic leukemic cell line HL-60 induced with etoposide. By means of TUNEL assay, the nuclei displayed a characteristic morphology change, and the amount of apoptotic cells increased early and reached maximun about 39% after treatment with etoposide for 2 h. Nucleosomal DNA fragmentation was observed after treatment for 4 h. The morphological change of HL-60 cells, thus, occurred earlier than the appearance of DNA ladder. Total nuclear matrix proteins were analyzed by 2-dimensional gel electrophoresis. Differential expression of 59 nuclear matrix proteins was found in 4 h etoposide treated cells. Western blotting was then performed on three nuclear matrix acssociated proteins, PML, HSC70 and NuMA. The expression of the suppressor PML protein and heat shock protein HSC70 were significantly upregulated after etoposide treatment, while NuMA, a nuclear mitotic apparatus protein, was down regulated. These results demonstrate that significant biochemical alterations in nuclear matrix proteins take place during the apoptotic process.
基金financially supported by the National Natural Science Foundation of China(Nos.51774030 and U1860104)the Fundamental Research Funds for the Central Universities,China(No.N2025019).
文摘In order to study the effect of continuous casting process parameters on the shape of slab solidification end under non-uniform cooling,a solidification model of a continuous-cast slab with non-uniform cooling condition was established with ProCAST software.The model was verified by the results of nail shooting tests and the infrared temperature measurement equipment.Four characteristic parameters were defined to evaluate the uniformity of the shape of slab solidification end.The results showed that the nonuniformity at the beginning and end of solidification,the solidification end length,and the solidification unevenness increased with the rise of casting speed.For each 10°C increase of superheat,the solidification unevenness increased by about 0.022.However,the effect of superheat on the solidification end length can be ignored.The secondary cooling strength showed minimal effect on the nonuniformity at the beginning and end of solidification.With the increase in secondary cooling intensity,the solidification end length decreased,but the solidification unevenness increased.In addition,the central segregation of the slab produced with and without the mechanical soft reduction(MSR)process was investigated.The transverse flow of molten steel with low solid fraction influenced the central segregation morphology under MSR.
