Sound velocity profile(SVP)data is indispensable in the multi-beam data processing.The sampling density is of great importance for SVP to represent the vertical variation of sound velocity accurately and guarantee the...Sound velocity profile(SVP)data is indispensable in the multi-beam data processing.The sampling density is of great importance for SVP to represent the vertical variation of sound velocity accurately and guarantee the accuracy of sound ray tracing(SRT).However,the SVP also affects the SRT efficiency significantly,especially in deep-sea multi-beam sounding data processing.To improve SRT efficiency and ensure SRT accuracy,an adaptive SVP simplification method based on area difference is proposed in this article.Firstly,the relationship between the area difference of the raw SVP and the simplified one and SRT bias is studied,and the relationship model of them is built.Then,by considering the constraint of SRT accuracy,the SVP simplification method and the simplifying SVP procedure SVP are given.Finally,a deep water experiment is conducted to verify the proposed method.Compared to the existing method,the proposed method improves the robustness,feasibility of SVP simplification as well as the accuracy and efficiency of SRT.展开更多
Delayed recovery from ulcerative colitis is mainly due to impaired healing of the intestinal epithelium after inflammation.The circadian rhythmcontrols cell proliferation and energy metabolism.However,the role of circ...Delayed recovery from ulcerative colitis is mainly due to impaired healing of the intestinal epithelium after inflammation.The circadian rhythmcontrols cell proliferation and energy metabolism.However,the role of circadian genes in inflammatory bowel disease is largely unknown.The purpose of this study was to investigate whether disrupting the circadian rhythm in mice can worsen colitis by altering mitochondrial energy metabolism.Mice in the experimental groups were under physiologic stress with an 8-h light shift jet-lag schedule every 3 days,whereas those in the control group were not.Subsequently,half of the mice in the control and jet-lagged groups were given dextran sodium sulfate(DSS)to induce colitis.Mice in each group were euthanized at zeitgeber time(ZT)0,ZT4,ZT8,ZT12,ZT16,and ZT20.To investigate the effects of jet lag on the mice,colon specimens were subjected to hematoxylin and eosin staining to analyse mRNA and protein expression of core circadian clock genes(Bmal1,Clock,Per1,Per2,Cry1,Cry2,and Nr1d1).We analysed the mitochondrial morphology,adenosine triphosphate(ATP)levels,and the expression of dynamin-related protein 1(Drp1)and ser637-phosphorylated(p)-Drp1,which are closely related to ATP production.We further investigated the effect of PER2 knockdown in the colon epithelial cells(CCD 841 CoN)by measuring ATP and cell proliferation levels.Disrupting the circadian rhythm changed the oscillation of clock genes in the colon of mice,altered the mitochondrial morphology of the colon specimens,decreased the expression of p-Drp1,reduced ATP production,and exacerbated inflammatory responses in mice with DSS-induced colitis.Additionally,silencing of PER2 in the colon epithelial cells reduced ATP production and cell proliferation.Disrupting the circadian rhythm in mice decreases mitochondrial energy metabolism in the colon and exacerbates symptoms of colitis.展开更多
文摘Sound velocity profile(SVP)data is indispensable in the multi-beam data processing.The sampling density is of great importance for SVP to represent the vertical variation of sound velocity accurately and guarantee the accuracy of sound ray tracing(SRT).However,the SVP also affects the SRT efficiency significantly,especially in deep-sea multi-beam sounding data processing.To improve SRT efficiency and ensure SRT accuracy,an adaptive SVP simplification method based on area difference is proposed in this article.Firstly,the relationship between the area difference of the raw SVP and the simplified one and SRT bias is studied,and the relationship model of them is built.Then,by considering the constraint of SRT accuracy,the SVP simplification method and the simplifying SVP procedure SVP are given.Finally,a deep water experiment is conducted to verify the proposed method.Compared to the existing method,the proposed method improves the robustness,feasibility of SVP simplification as well as the accuracy and efficiency of SRT.
基金supported by National Key R&D Program of China[No.2018YFC0114600]National Natural Science Foundation of China[No.82170547,No.81873558].
文摘Delayed recovery from ulcerative colitis is mainly due to impaired healing of the intestinal epithelium after inflammation.The circadian rhythmcontrols cell proliferation and energy metabolism.However,the role of circadian genes in inflammatory bowel disease is largely unknown.The purpose of this study was to investigate whether disrupting the circadian rhythm in mice can worsen colitis by altering mitochondrial energy metabolism.Mice in the experimental groups were under physiologic stress with an 8-h light shift jet-lag schedule every 3 days,whereas those in the control group were not.Subsequently,half of the mice in the control and jet-lagged groups were given dextran sodium sulfate(DSS)to induce colitis.Mice in each group were euthanized at zeitgeber time(ZT)0,ZT4,ZT8,ZT12,ZT16,and ZT20.To investigate the effects of jet lag on the mice,colon specimens were subjected to hematoxylin and eosin staining to analyse mRNA and protein expression of core circadian clock genes(Bmal1,Clock,Per1,Per2,Cry1,Cry2,and Nr1d1).We analysed the mitochondrial morphology,adenosine triphosphate(ATP)levels,and the expression of dynamin-related protein 1(Drp1)and ser637-phosphorylated(p)-Drp1,which are closely related to ATP production.We further investigated the effect of PER2 knockdown in the colon epithelial cells(CCD 841 CoN)by measuring ATP and cell proliferation levels.Disrupting the circadian rhythm changed the oscillation of clock genes in the colon of mice,altered the mitochondrial morphology of the colon specimens,decreased the expression of p-Drp1,reduced ATP production,and exacerbated inflammatory responses in mice with DSS-induced colitis.Additionally,silencing of PER2 in the colon epithelial cells reduced ATP production and cell proliferation.Disrupting the circadian rhythm in mice decreases mitochondrial energy metabolism in the colon and exacerbates symptoms of colitis.
