Natural gas hydrate(NGH)is generally produced and accumulated together with the underlying conventional gas.Therefore,optimizing the production technology of these two gases should be seen as a relevant way to effecti...Natural gas hydrate(NGH)is generally produced and accumulated together with the underlying conventional gas.Therefore,optimizing the production technology of these two gases should be seen as a relevant way to effectively reduce the exploitation cost of the gas hydrate.In this study,three types of models accounting for the coexistence of these gases are considered.Type A considers the upper hydrate-bearing layer(HBL)adjacent to the lower conventional gas layer(CGL);with the Type B a permeable interlayer exists between the upper HBL and the lower CGL;with the type C there is an impermeable interlayer between the upper HBL and the lower CGL.The production performances associated with the above three models are calculated under different conditions,including only a depressurized HBL(only HBL DP);only a depressurized CGL(only CGL DP);and both the HBL and the CGL being depressurized(HBL+CGL DP).The results show that for Type A and Type B coexistence accumulation models,when only HBL or CGL is depressurized,the gas from the other layer will flow into the production layer due to the pressure difference between the two layers.In the coexistence accumulation model of type C,the cumulative gas production is much lower than that of Type A and Type B,regardless of whether only HBL DP,only CGL DP,or HBL+CGL DP are considered.This indicates that the impermeable interlayer restricts the cross-flow of gas between HBL and CGL.For three different coexistence accumulation models,CGL DP has the largest gas-to-water ratio.展开更多
XML data can be represented by a tree or graph and the query processing for XML data requires the structural information among nodes. Designing an efficient labeling scheme for the nodes of Order-Sensitive XML trees i...XML data can be represented by a tree or graph and the query processing for XML data requires the structural information among nodes. Designing an efficient labeling scheme for the nodes of Order-Sensitive XML trees is one of the important methods to obtain the excellent management of XML data. Previous labeling schemes such as region and prefix often sacrifice updating performance and suffer increasing labeling space when inserting new nodes. To overcome these limitations, in this paper we propose a new labeling idea of separating structure from order. According to the proposed idea, a novel Prime-based Middle Fraction Labeling Scheme(PMFLS) is designed accordingly, in which a series of algorithms are proposed to obtain the structural relationships among nodes and to support updates. PMFLS combines the advantages of both prefix and region schemes in which the structural information and sequential information are separately expressed. PMFLS also supports Order-Sensitive updates without relabeling or recalculation, and its labeling space is stable. Experiments and analysis on several benchmarks are conducted and the results show that PMFLS is efficient in handling updates and also significantly improves the performance of the query processing with good scalability.展开更多
The shortage of donor livers has led to an increased use of organs from expanded criteria donors. Included are livers with steatosis, a metabolic abnormality that increases the likelihood of graft complications posttr...The shortage of donor livers has led to an increased use of organs from expanded criteria donors. Included are livers with steatosis, a metabolic abnormality that increases the likelihood of graft complications posttransplantation. After a brief introduction on the etiology, pathophysiology, categories and experimental models of hepatic steatosis, we herein review the methods to rescue steatotic donor livers before transplantation applied in clinical and experimental studies. The methods span the spectrum of encouraging donor weight loss, employing drug therapy, heat shock preconditioning, ischemia preconditioning and selective anesthesia on donors, and the treatment on isolated grafts during preservation. These methods work at different stages of transplantation process, although share similar molecular mechanisms including lipid metabolism stimulation through enzymes or nuclear receptor e.g. , peroxisomal proliferator-activated receptor, or anti-inflammation through suppressing cytokines e.g. , tumor necrosis factor-α, or antioxidant therapies to alleviate oxidative stress. This similarity of molecular mechanisms implies possible future attempts to reinforce each approach by repeating the same treatment approach at several stages of procurement and preservation, as well as utilizing these alternative approaches in tandem.展开更多
Background:Recent studies highlight pseudogene derived long non-coding RNAs(lncRNAs)as key regulators of cancer biology.However,few of them have been well characterized in pancreatic cancer.Here,we aimed to identify t...Background:Recent studies highlight pseudogene derived long non-coding RNAs(lncRNAs)as key regulators of cancer biology.However,few of them have been well characterized in pancreatic cancer.Here,we aimed to identify the association between pseudogene derived lncRNA DUXAP8 and growth of pancreatic cancer cells.Methods:We screened for pseudogene derived lncRNAs associated with human pancreatic cancer by compara-tive analysis of three independent datasets from GEO.Quantitative real-time reverse transcription polymerase chain reaction was used to assess the relative expression of DUXAP8 in pancreatic cancer tissues and cells.Loss-of-function approaches were used to investigate the potential functional roles of DUXAP8 in pancreatic cancer cell proliferation and apoptosis in vitro and in vivo.RNA immunoprecipitation,chromosome immunoprecipitation assay and rescue experiments were performed to analyze the association of DUXAP8 with target proteins and genes in pancreatic cancer cells.Results:Pancreatic cancer tissues had significantly higher DUXAP8 levels than paired adjacent normal tissues.High DUXAP8 expression was associated with a larger tumor size,advanced pathological stage and shorter overall survival of pancreatic cancer patients.Moreover,silencing DUXAP8 expression by siRNA or shRNA inhibited pancreatic cancer cell proliferation and promoted apoptosis in vitro and in vivo.Mechanistic analyses indicated that DUXAP8 regulates PC cell proliferation partly through downregulation of tumor suppressor CDKN1A and KLF2 expression.Conclusion:Our results suggest that tumor expression of pseudogene derived lncRNA DUXAP8 plays an important role in pancreatic cancer progression.DUXAP8 may serve as a candidate biomarker and represent a novel therapeutic target of pancreatic cancer.展开更多
Dear Editor,Early diagnosis is critical for successful treatment of gastric adenocarcinoma(GA).However,the sensitivities of tumor markers carcinoembryonic antigen(CEA),cancer antigen 19-9(CA19-9)and CA72-4 for GA dete...Dear Editor,Early diagnosis is critical for successful treatment of gastric adenocarcinoma(GA).However,the sensitivities of tumor markers carcinoembryonic antigen(CEA),cancer antigen 19-9(CA19-9)and CA72-4 for GA detection are approximately 20%[1],and the sensitivities of all markers combined for early gastric cancer detection is still very low[2].DNA methylation plays a major role in tumorigenesis and therefore has obvious potential as a non-invasive biomarker for cancer detection[3].Through genome-wide methylation analysis and histological verification,we previously identified ring finger protein 180(RNF180)as a novel preferentially methylated gene in GA[4,5].展开更多
基金supported by the National Natural Science Foundation of China (Nos.52074334,51991365)the National Key R&D Program of China (2021YFC2800903),which are gratefully acknowledged.
文摘Natural gas hydrate(NGH)is generally produced and accumulated together with the underlying conventional gas.Therefore,optimizing the production technology of these two gases should be seen as a relevant way to effectively reduce the exploitation cost of the gas hydrate.In this study,three types of models accounting for the coexistence of these gases are considered.Type A considers the upper hydrate-bearing layer(HBL)adjacent to the lower conventional gas layer(CGL);with the Type B a permeable interlayer exists between the upper HBL and the lower CGL;with the type C there is an impermeable interlayer between the upper HBL and the lower CGL.The production performances associated with the above three models are calculated under different conditions,including only a depressurized HBL(only HBL DP);only a depressurized CGL(only CGL DP);and both the HBL and the CGL being depressurized(HBL+CGL DP).The results show that for Type A and Type B coexistence accumulation models,when only HBL or CGL is depressurized,the gas from the other layer will flow into the production layer due to the pressure difference between the two layers.In the coexistence accumulation model of type C,the cumulative gas production is much lower than that of Type A and Type B,regardless of whether only HBL DP,only CGL DP,or HBL+CGL DP are considered.This indicates that the impermeable interlayer restricts the cross-flow of gas between HBL and CGL.For three different coexistence accumulation models,CGL DP has the largest gas-to-water ratio.
基金supported by the National Science Foundation of China(Grant No.61272067,61370229)the National Key Technology R&D Program of China(Grant No.2012BAH27F05,2013BAH72B01)+1 种基金the National High Technology R&D Program of China(Grant No.2013AA01A212)the S&T Projects of Guangdong Province(Grant No.2016B010109008,2014B010117007,2015A030401087,2015B010109003,2015B010110002)
文摘XML data can be represented by a tree or graph and the query processing for XML data requires the structural information among nodes. Designing an efficient labeling scheme for the nodes of Order-Sensitive XML trees is one of the important methods to obtain the excellent management of XML data. Previous labeling schemes such as region and prefix often sacrifice updating performance and suffer increasing labeling space when inserting new nodes. To overcome these limitations, in this paper we propose a new labeling idea of separating structure from order. According to the proposed idea, a novel Prime-based Middle Fraction Labeling Scheme(PMFLS) is designed accordingly, in which a series of algorithms are proposed to obtain the structural relationships among nodes and to support updates. PMFLS combines the advantages of both prefix and region schemes in which the structural information and sequential information are separately expressed. PMFLS also supports Order-Sensitive updates without relabeling or recalculation, and its labeling space is stable. Experiments and analysis on several benchmarks are conducted and the results show that PMFLS is efficient in handling updates and also significantly improves the performance of the query processing with good scalability.
基金Supported by Grants from the United States National Institutes of Health, R01DK59766 to Yarmush M R00DK080942 and R01DK096075 to Uygun K
文摘The shortage of donor livers has led to an increased use of organs from expanded criteria donors. Included are livers with steatosis, a metabolic abnormality that increases the likelihood of graft complications posttransplantation. After a brief introduction on the etiology, pathophysiology, categories and experimental models of hepatic steatosis, we herein review the methods to rescue steatotic donor livers before transplantation applied in clinical and experimental studies. The methods span the spectrum of encouraging donor weight loss, employing drug therapy, heat shock preconditioning, ischemia preconditioning and selective anesthesia on donors, and the treatment on isolated grafts during preservation. These methods work at different stages of transplantation process, although share similar molecular mechanisms including lipid metabolism stimulation through enzymes or nuclear receptor e.g. , peroxisomal proliferator-activated receptor, or anti-inflammation through suppressing cytokines e.g. , tumor necrosis factor-α, or antioxidant therapies to alleviate oxidative stress. This similarity of molecular mechanisms implies possible future attempts to reinforce each approach by repeating the same treatment approach at several stages of procurement and preservation, as well as utilizing these alternative approaches in tandem.
基金supported by grants from the National Natural Science Foundation of China(Nos.81602052,8160100460,and 8157040399).
文摘Background:Recent studies highlight pseudogene derived long non-coding RNAs(lncRNAs)as key regulators of cancer biology.However,few of them have been well characterized in pancreatic cancer.Here,we aimed to identify the association between pseudogene derived lncRNA DUXAP8 and growth of pancreatic cancer cells.Methods:We screened for pseudogene derived lncRNAs associated with human pancreatic cancer by compara-tive analysis of three independent datasets from GEO.Quantitative real-time reverse transcription polymerase chain reaction was used to assess the relative expression of DUXAP8 in pancreatic cancer tissues and cells.Loss-of-function approaches were used to investigate the potential functional roles of DUXAP8 in pancreatic cancer cell proliferation and apoptosis in vitro and in vivo.RNA immunoprecipitation,chromosome immunoprecipitation assay and rescue experiments were performed to analyze the association of DUXAP8 with target proteins and genes in pancreatic cancer cells.Results:Pancreatic cancer tissues had significantly higher DUXAP8 levels than paired adjacent normal tissues.High DUXAP8 expression was associated with a larger tumor size,advanced pathological stage and shorter overall survival of pancreatic cancer patients.Moreover,silencing DUXAP8 expression by siRNA or shRNA inhibited pancreatic cancer cell proliferation and promoted apoptosis in vitro and in vivo.Mechanistic analyses indicated that DUXAP8 regulates PC cell proliferation partly through downregulation of tumor suppressor CDKN1A and KLF2 expression.Conclusion:Our results suggest that tumor expression of pseudogene derived lncRNA DUXAP8 plays an important role in pancreatic cancer progression.DUXAP8 may serve as a candidate biomarker and represent a novel therapeutic target of pancreatic cancer.
基金supported by the National Key R&D Program of China(Grant no.2016YFC1303200,2022YFC2505100,2017YFC0908300,and 2018YFC1313101)Tianjin Key Medical Discipline(Specialty)Construction Project(Grant no.TJYXZDXK-009A)Beijing Munic-ipal Science&Technology Commission,Administrative Commission of Zhongguancun Science Park(Grant no.Z201100005420007).
文摘Dear Editor,Early diagnosis is critical for successful treatment of gastric adenocarcinoma(GA).However,the sensitivities of tumor markers carcinoembryonic antigen(CEA),cancer antigen 19-9(CA19-9)and CA72-4 for GA detection are approximately 20%[1],and the sensitivities of all markers combined for early gastric cancer detection is still very low[2].DNA methylation plays a major role in tumorigenesis and therefore has obvious potential as a non-invasive biomarker for cancer detection[3].Through genome-wide methylation analysis and histological verification,we previously identified ring finger protein 180(RNF180)as a novel preferentially methylated gene in GA[4,5].
