The exploration and development of oil and gas resources have shifted from shallow to deep and ultradeep.The difficulty of rock breaking has also increased,introducing new challenges to traditional rock-breaking techn...The exploration and development of oil and gas resources have shifted from shallow to deep and ultradeep.The difficulty of rock breaking has also increased,introducing new challenges to traditional rock-breaking technology.Hence,there is an urgent need to develop new rock-breaking technologies to improve the development efficiency of deep oil and gas resources.Therefore,this study focused on the new microwave rock-breaking technology and conducted experimental and numerical simulation research on typical deep,hard rock granite.The research results showed that granite in the microwave field exhibited high-temperature melting and fracture,and the highest temperature could reach 550°C.Under the irradiation of circulating microwaves,a minimum irradiation time threshold of 3 min was needed to cause irreversible damage to the rock.The numerical simulation results showed that the interaction of thermal stress and in situ stress would cause the inside of the rock stratum to separate into a disturbed deterioration area,disturbed unloading area and initial stress area.These results are expected to provide the necessary technical guidance and theoretical support for the research and development of high-efficiency rock-breaking drilling for deep hard rock.展开更多
AIM： To study the expression of vascular endothelial growth factor A （VEGF-A） and VEGF-C and to determine whether the presence of VEGF-A and VEGF-C was associated with the clinicopathologic characteristics of pancr...AIM： To study the expression of vascular endothelial growth factor A （VEGF-A） and VEGF-C and to determine whether the presence of VEGF-A and VEGF-C was associated with the clinicopathologic characteristics of pancreatic cancer. METHODS： VEGF-A and VEGF-C mRNA transcripts were examined by Northern blot in 6 human pancreatic cancer cell lines and 8 normal pancreatic tissues and 8 pancreatic carcinoma specimens. The expression of VEGF-A and VEGF-C proteins was examined by Western blot in the tested cell lines and by immunohistochemical stain in 50 pancreatic carcinoma samples. RESULTS： VEGF-A and VEGF-C mRNA transcripts were present in all the 6 human pancreatic cancer cell lines. Immunoblotting revealed the presence of VEGF-A and VEGF-C proteins in all the cell lines. Northern blot analysis of total RNA revealed 3.0-fold and 3.6-fold increase in VEGF-A and VEGF-C mRNA transcript in the cancer samples, respectively. Immunohistochemical analysis confirmed the expression of VEGF-A and VEGF-C in cancer cells within the tumor mass. Immunohistochemical analysis of 50 pancreatic cancer tissue samples revealed the presence of VEGF-A and VEGF-C immunoreactivity in 50% and 80% of the cancer tissue samples, respectively. The presence of VEGF-A in these cells was associated with larger tumor size and enhanced local spread （x^2= 6.690, P= 0.035〈0.05） but was not associated with decreased patient survival. However, the presence of VEGF-C in the cancer cells was associated with increased lymph node metastasis （x^2= 5.710, P= 0.017〈0.05）,but was not associated with decreased patient survival. There was no correlation between the expression of VEGF-A and VEGF-C in the same cancer cells. CONCLUSION： VEGF-A and VEGF-C are commonly overexpressed in human pancreatic cancer and may contribute to tumor growth and lymph node metastasis, There is no relationship between the expression of VEGF-A and VEGF-C in pancreatic cancer.展开更多
Vascular endothelial growth factor (VEGF, namely VEGF-A) is an angiogenic polypeptide and VEGF-C is a lymphangiogenic polypeptide that has been implicated in cancer growth, invasion and metastasis. Several cytokines a...Vascular endothelial growth factor (VEGF, namely VEGF-A) is an angiogenic polypeptide and VEGF-C is a lymphangiogenic polypeptide that has been implicated in cancer growth, invasion and metastasis. Several cytokines and growth factors play an important part in cancer progression. These cytokines and growth factors are the principal mediators of cancer cells-stromal cell interaction , which is critical for invasion of cancer cells to the surrounding tissues and metastatic dissemination to distant organs. In this study, we studied VEGF-A, C expression in cultured human pancreatic cancer cell lines and whether the presence of VEGF-A, C in the cell lines is regulated by cytokines interleukin-lct (EL-1α), and interleukin-6 (IL-6). METHODS: We used Northern blot and Western blot methods to analyze expression of the gene and protein of VEGF-A, C in all 6 tested cell lines (ASPC-1, CAPAN-1, MIA-PaCa-2, PANC-1, COLO-357 and T3M4) respectively. To analyze what is the regulator for this VEGF-A, C expression in pancreatic cancer,we used the reverse transcription -polymerase chain reaction (RT-PCR) method to analyze VEGF-A, C expression in cultured human pancreatic cancer cell lines (CAPAN-1 and COLO-357) under the stimulation with IL-1α (10μg/L) or IL-6 (100 μg/L). RESULTS:Northern blot analysis revealed the presence of the 4.1-kb VEGF-A mRNA transcript and 2.4-kb VEGF-C mRNA transcript in all 6 tested cell lines. Immunoblotting with highly specific anti-VEGF-A, anti-VEGF-C antibody revealed the presence of a molecular weight of 43-kDa VEGF-A protein and 55-kDa VEGF-C protein in all the cell lines. RT-PCR analysis revealed the levels of the VEGF-A and VEGF-C gene were 1-2 fold and a 1-fold increase in the COLO-357 cell line by stimulation with IL-la, however, no effect was found in the CAPAN-1 cell line. The levels of the VEGF-A and VEGF-C gene were 2-5 fold and a 1-fold increase in the CAPAN-1 cell line by stimulation with IL-6, but, no effect was found in the COLO-357 cell line. CONCLUSION:These findings suggested that the expression of VEGF-A, C and their regulation by IL-1α, IL-6 in pancreatic cancer contributes to the lymphatic and distant metastasis and the disease progression.展开更多
基金financially supported by National Natural Science Foundation of China(U2013603,52004167)Program for Guangdong Introducing Innovative and Enterpreneurial Teams(No.2019ZT08G315)China Postdoctoral Science Foundation(2021T140485)
文摘The exploration and development of oil and gas resources have shifted from shallow to deep and ultradeep.The difficulty of rock breaking has also increased,introducing new challenges to traditional rock-breaking technology.Hence,there is an urgent need to develop new rock-breaking technologies to improve the development efficiency of deep oil and gas resources.Therefore,this study focused on the new microwave rock-breaking technology and conducted experimental and numerical simulation research on typical deep,hard rock granite.The research results showed that granite in the microwave field exhibited high-temperature melting and fracture,and the highest temperature could reach 550°C.Under the irradiation of circulating microwaves,a minimum irradiation time threshold of 3 min was needed to cause irreversible damage to the rock.The numerical simulation results showed that the interaction of thermal stress and in situ stress would cause the inside of the rock stratum to separate into a disturbed deterioration area,disturbed unloading area and initial stress area.These results are expected to provide the necessary technical guidance and theoretical support for the research and development of high-efficiency rock-breaking drilling for deep hard rock.
基金Supported by grant from Ministry of Education of China, No. 2002247
文摘AIM： To study the expression of vascular endothelial growth factor A （VEGF-A） and VEGF-C and to determine whether the presence of VEGF-A and VEGF-C was associated with the clinicopathologic characteristics of pancreatic cancer. METHODS： VEGF-A and VEGF-C mRNA transcripts were examined by Northern blot in 6 human pancreatic cancer cell lines and 8 normal pancreatic tissues and 8 pancreatic carcinoma specimens. The expression of VEGF-A and VEGF-C proteins was examined by Western blot in the tested cell lines and by immunohistochemical stain in 50 pancreatic carcinoma samples. RESULTS： VEGF-A and VEGF-C mRNA transcripts were present in all the 6 human pancreatic cancer cell lines. Immunoblotting revealed the presence of VEGF-A and VEGF-C proteins in all the cell lines. Northern blot analysis of total RNA revealed 3.0-fold and 3.6-fold increase in VEGF-A and VEGF-C mRNA transcript in the cancer samples, respectively. Immunohistochemical analysis confirmed the expression of VEGF-A and VEGF-C in cancer cells within the tumor mass. Immunohistochemical analysis of 50 pancreatic cancer tissue samples revealed the presence of VEGF-A and VEGF-C immunoreactivity in 50% and 80% of the cancer tissue samples, respectively. The presence of VEGF-A in these cells was associated with larger tumor size and enhanced local spread （x^2= 6.690, P= 0.035〈0.05） but was not associated with decreased patient survival. However, the presence of VEGF-C in the cancer cells was associated with increased lymph node metastasis （x^2= 5.710, P= 0.017〈0.05）,but was not associated with decreased patient survival. There was no correlation between the expression of VEGF-A and VEGF-C in the same cancer cells. CONCLUSION： VEGF-A and VEGF-C are commonly overexpressed in human pancreatic cancer and may contribute to tumor growth and lymph node metastasis, There is no relationship between the expression of VEGF-A and VEGF-C in pancreatic cancer.
基金This work was supported by a grant from the Chinese Ministry of Education,China(JWSL 2002247).
文摘Vascular endothelial growth factor (VEGF, namely VEGF-A) is an angiogenic polypeptide and VEGF-C is a lymphangiogenic polypeptide that has been implicated in cancer growth, invasion and metastasis. Several cytokines and growth factors play an important part in cancer progression. These cytokines and growth factors are the principal mediators of cancer cells-stromal cell interaction , which is critical for invasion of cancer cells to the surrounding tissues and metastatic dissemination to distant organs. In this study, we studied VEGF-A, C expression in cultured human pancreatic cancer cell lines and whether the presence of VEGF-A, C in the cell lines is regulated by cytokines interleukin-lct (EL-1α), and interleukin-6 (IL-6). METHODS: We used Northern blot and Western blot methods to analyze expression of the gene and protein of VEGF-A, C in all 6 tested cell lines (ASPC-1, CAPAN-1, MIA-PaCa-2, PANC-1, COLO-357 and T3M4) respectively. To analyze what is the regulator for this VEGF-A, C expression in pancreatic cancer,we used the reverse transcription -polymerase chain reaction (RT-PCR) method to analyze VEGF-A, C expression in cultured human pancreatic cancer cell lines (CAPAN-1 and COLO-357) under the stimulation with IL-1α (10μg/L) or IL-6 (100 μg/L). RESULTS:Northern blot analysis revealed the presence of the 4.1-kb VEGF-A mRNA transcript and 2.4-kb VEGF-C mRNA transcript in all 6 tested cell lines. Immunoblotting with highly specific anti-VEGF-A, anti-VEGF-C antibody revealed the presence of a molecular weight of 43-kDa VEGF-A protein and 55-kDa VEGF-C protein in all the cell lines. RT-PCR analysis revealed the levels of the VEGF-A and VEGF-C gene were 1-2 fold and a 1-fold increase in the COLO-357 cell line by stimulation with IL-la, however, no effect was found in the CAPAN-1 cell line. The levels of the VEGF-A and VEGF-C gene were 2-5 fold and a 1-fold increase in the CAPAN-1 cell line by stimulation with IL-6, but, no effect was found in the COLO-357 cell line. CONCLUSION:These findings suggested that the expression of VEGF-A, C and their regulation by IL-1α, IL-6 in pancreatic cancer contributes to the lymphatic and distant metastasis and the disease progression.
