Laser ignition of lean fuels offers a promising route for green combustion with high combustion efficiency and low exhaust emissions. The fundamental limitations which apply to femtosecond laser ignition(fs-LI) of lea...Laser ignition of lean fuels offers a promising route for green combustion with high combustion efficiency and low exhaust emissions. The fundamental limitations which apply to femtosecond laser ignition(fs-LI) of lean fuels are the inferior energy deposition and low thermodynamic temperature. However, it was discovered recently that the fs laser filamentation can induce 100% success rate of fs-LI with ultralow sub-m J minimum ignition energy, exhibiting distinct contrast to the general understanding that it is hard to achieve fs-LI. The present contribution examines the extent to which the minimum ignition energies depend on filamentation formation, and explores the key factors for the success of fs-LI. We perform fs-LI of a lean-fuel CH;/air mixture using a femtosecond near-infrared(~40 fs, 800 nm) pulse at different external focal conditions, and find a Goldilocks focal zone to facilitate fs-LI. In this special zone, a crucial balance between the length of igniting “line” kernel and the plasma density of the fs laser filament is achieved, which determines not only the total amount of resultant OH radicals, but also their distribution along the plasma filament. Our finding provides a viable strategy with clear guidelines for fs-LI, and also opens up an avenue of exploring unprecedented ultrafast ignition dynamics after fs-laser-fuel interactions towards gaining deeper insights into reaction intermediates and combustion processes.展开更多
Postoperative hepatic insulin-like growth factor-1(IGF-1)production may be severely disturbed in patients with liver cirrhosis.Complex alterations in the GH/IGF-1 axis are thought to play an important role in the prot...Postoperative hepatic insulin-like growth factor-1(IGF-1)production may be severely disturbed in patients with liver cirrhosis.Complex alterations in the GH/IGF-1 axis are thought to play an important role in the protein catabolism that complicates major surgical procedures.The aim of this study was to explore the effects of parenteral nutrition(PN)with and without growth hormone(GH)on the GH/IGF-1 axis after hepatectomy for hepatocellular carcinoma(HCC)with cirrhosis and evaluate the potential roles of recombinant human GH(rhGH)therapy.Twenty-four patients with HCC with cirrhosis who underwent hepatectomy were randomly divided into two groups:a PN group(n=12)and an rhGH+PN group(n=12).Liver function,serum GH,IGF-1 and IGFBP-3 were measured before the operation and at postoperative days(POD)1 and 6.Insulin-like growth factor-1 and IGFBP-3 mRNA in the liver tissue was detected by RT-PCR.The liver Ki67 immunohistochemistry staining was studied.At the same time,12 patients with cholelithiasis or liver hemangioma who underwent operation served as normal control group.On POD 6,serum prealbumin,GH,IGF-1,IGFBP-3,hepatic IGF-1 mRNA,IGFBP-3 mRNA and liver Ki67 LI were higher in the rhGH+PN group than in the PN group.There was no significant difference in the 6-and 12-month tumor-free survival rate and the median tumor-free survival time between the PN group and the rhGH+PN group(P>0.05).These data indicate that rhGH+PN could ameliorate the changes in the GH/IGF-1 axis after hepatectomy for HCC in the setting of cirrhosis.展开更多
The fragile histidine triad(FHIT)gene,a candidate tumor suppressor gene located at 3p14.2,has been shown to be involved in the carcinogenesis of many human tissues,including digestive tract tissues.However,the express...The fragile histidine triad(FHIT)gene,a candidate tumor suppressor gene located at 3p14.2,has been shown to be involved in the carcinogenesis of many human tissues,including digestive tract tissues.However,the expression and the role of the FHIT in the initiation and the development of the colorectal cancer(CRC)are poorly understood.We have shown that the FHIT gene exhibits significantly decreased expression in human CRC compared to colorectal adenoma and normal colorectal tissue by tissue microarray(TMA).The positive rate of FHIT gene expression in normal colorectal tissue,adenoma and adenocarcinoma were 93.75%,68.75%and 46.25%,respectively.We show this decreased expression to be significantly correlated with the progression of colorectal carcinoma(P<0.05)as well as with differentiation and lymph node metastasis(P<0.05).We detected two somatic alterations in the FHIT gene in human CRC.The presence of this mutation correlated significantly with decreased FHIT expression in the human CRC.In our present study we tested the hypothesis that the decreased FHIT expression resulted in apoptosis inhibition associated with abnormal expression of apoptosis related proteins.To test this hypothesis we did a series of experiments.In the first test,we assessed apoptosis status using a standard TUNEL(terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling)assay by comparing FHIT-positive CRC vs.FHIT-negative CRC.In the second experiment,the protein expression of the FHIT and other apoptosis related proteins(Bax,Bcl-2 and Survivin)were measured in human CRC by TMA.Our combined results demonstrate the mutation in the FHIT gene significantly reduced FHIT expression in human CRC.Both TUNEL and TMA experiments demonstrated significantly inhibited apoptosis by down-regulation of Bax and the up-regulation of Survivin and Bcl-2.Collectively,these studies identify the mechanism by which an important tumor suppressor gene,FHIT is inactivated specifically in human CRC contributing to our understanding of the mechanism of colorectal carcinogenesis.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 62027822 and 11904121)。
文摘Laser ignition of lean fuels offers a promising route for green combustion with high combustion efficiency and low exhaust emissions. The fundamental limitations which apply to femtosecond laser ignition(fs-LI) of lean fuels are the inferior energy deposition and low thermodynamic temperature. However, it was discovered recently that the fs laser filamentation can induce 100% success rate of fs-LI with ultralow sub-m J minimum ignition energy, exhibiting distinct contrast to the general understanding that it is hard to achieve fs-LI. The present contribution examines the extent to which the minimum ignition energies depend on filamentation formation, and explores the key factors for the success of fs-LI. We perform fs-LI of a lean-fuel CH;/air mixture using a femtosecond near-infrared(~40 fs, 800 nm) pulse at different external focal conditions, and find a Goldilocks focal zone to facilitate fs-LI. In this special zone, a crucial balance between the length of igniting “line” kernel and the plasma density of the fs laser filament is achieved, which determines not only the total amount of resultant OH radicals, but also their distribution along the plasma filament. Our finding provides a viable strategy with clear guidelines for fs-LI, and also opens up an avenue of exploring unprecedented ultrafast ignition dynamics after fs-laser-fuel interactions towards gaining deeper insights into reaction intermediates and combustion processes.
文摘Postoperative hepatic insulin-like growth factor-1(IGF-1)production may be severely disturbed in patients with liver cirrhosis.Complex alterations in the GH/IGF-1 axis are thought to play an important role in the protein catabolism that complicates major surgical procedures.The aim of this study was to explore the effects of parenteral nutrition(PN)with and without growth hormone(GH)on the GH/IGF-1 axis after hepatectomy for hepatocellular carcinoma(HCC)with cirrhosis and evaluate the potential roles of recombinant human GH(rhGH)therapy.Twenty-four patients with HCC with cirrhosis who underwent hepatectomy were randomly divided into two groups:a PN group(n=12)and an rhGH+PN group(n=12).Liver function,serum GH,IGF-1 and IGFBP-3 were measured before the operation and at postoperative days(POD)1 and 6.Insulin-like growth factor-1 and IGFBP-3 mRNA in the liver tissue was detected by RT-PCR.The liver Ki67 immunohistochemistry staining was studied.At the same time,12 patients with cholelithiasis or liver hemangioma who underwent operation served as normal control group.On POD 6,serum prealbumin,GH,IGF-1,IGFBP-3,hepatic IGF-1 mRNA,IGFBP-3 mRNA and liver Ki67 LI were higher in the rhGH+PN group than in the PN group.There was no significant difference in the 6-and 12-month tumor-free survival rate and the median tumor-free survival time between the PN group and the rhGH+PN group(P>0.05).These data indicate that rhGH+PN could ameliorate the changes in the GH/IGF-1 axis after hepatectomy for HCC in the setting of cirrhosis.
基金This work was supported by Natural Science Foundation of Guangdong Province(No.06020005)。
文摘The fragile histidine triad(FHIT)gene,a candidate tumor suppressor gene located at 3p14.2,has been shown to be involved in the carcinogenesis of many human tissues,including digestive tract tissues.However,the expression and the role of the FHIT in the initiation and the development of the colorectal cancer(CRC)are poorly understood.We have shown that the FHIT gene exhibits significantly decreased expression in human CRC compared to colorectal adenoma and normal colorectal tissue by tissue microarray(TMA).The positive rate of FHIT gene expression in normal colorectal tissue,adenoma and adenocarcinoma were 93.75%,68.75%and 46.25%,respectively.We show this decreased expression to be significantly correlated with the progression of colorectal carcinoma(P<0.05)as well as with differentiation and lymph node metastasis(P<0.05).We detected two somatic alterations in the FHIT gene in human CRC.The presence of this mutation correlated significantly with decreased FHIT expression in the human CRC.In our present study we tested the hypothesis that the decreased FHIT expression resulted in apoptosis inhibition associated with abnormal expression of apoptosis related proteins.To test this hypothesis we did a series of experiments.In the first test,we assessed apoptosis status using a standard TUNEL(terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling)assay by comparing FHIT-positive CRC vs.FHIT-negative CRC.In the second experiment,the protein expression of the FHIT and other apoptosis related proteins(Bax,Bcl-2 and Survivin)were measured in human CRC by TMA.Our combined results demonstrate the mutation in the FHIT gene significantly reduced FHIT expression in human CRC.Both TUNEL and TMA experiments demonstrated significantly inhibited apoptosis by down-regulation of Bax and the up-regulation of Survivin and Bcl-2.Collectively,these studies identify the mechanism by which an important tumor suppressor gene,FHIT is inactivated specifically in human CRC contributing to our understanding of the mechanism of colorectal carcinogenesis.
