BACKGROUND Acute lung injury(ALI)is a common and life-threatening complication of severe acute pancreatitis(SAP).There are currently limited effective treatment options for SAP and associated ALI.Calycosin(Cal),a bioa...BACKGROUND Acute lung injury(ALI)is a common and life-threatening complication of severe acute pancreatitis(SAP).There are currently limited effective treatment options for SAP and associated ALI.Calycosin(Cal),a bioactive constituent extracted from the medicinal herb Radix Astragali exhibits potent anti-inflammatory properties,but its effect on SAP and associated ALI has yet to be determined.AIM To identify the roles of Cal in SAP-ALI and the underlying mechanism.METHODS SAP was induced via two intraperitoneal injections of L-arg(4 g/kg)and Cal(25 or 50 mg/kg)were injected 1 h prior to the first L-arg challenge.Mice were sacrificed 72 h after the induction of SAP and associated ALI was examined histologically and biochemically.An in vitro model of lipopolysaccharide(LPS)-induced ALI was established using A549 cells.Immunofluorescence analysis and western blot were evaluated in cells.Molecular docking analyses were conducted to examine the interaction of Cal with HMGB1.RESULTS Cal treatment substantially reduced the serum amylase levels and alleviated histopathological injury associated with SAP and ALI.Neutrophil infiltration and lung tissue levels of neutrophil mediator myeloperoxidase were reduced in line with protective effects of Cal against ALI in SAP.Cal treatment also attenuated the serum levels and mRNA expression of pro-inflammatory cytokines tumor necrosis factor-α,interleukin-6,IL-1β,HMGB1 and chemokine(CXC motif)ligand 1 in lung tissue.Immunofluorescence and western blot analyses showed that Cal treatment markedly suppressed the expression of HMGB1 and phosphorylated nuclear factor-kappa B(NF-κB)p65 in lung tissues and an in vitro model of LPSinduced ALI in A549 cells suggesting a role for HGMB1 in the pathogenesis of ALI.Furthermore,molecular docking analysis provided evidence for the direct interaction of Cal with HGMB1.CONCLUSION Cal protects mice against L-arg-induced SAP and associated ALI by attenuating local and systemic neutrophil infiltration and inflammatory response via inhibition of HGMB1 and the NF-κB signaling pathway.展开更多
The migration mode transition of cancer cell enhances its invasive capability and the drug resistance,where physical confinement of cell microenvironment has been revealed to induce the mesenchymal-amoeboid transition...The migration mode transition of cancer cell enhances its invasive capability and the drug resistance,where physical confinement of cell microenvironment has been revealed to induce the mesenchymal-amoeboid transition(MAT).However,most existing studies are performed in PDMS microchannels,of which the stiffness is much higher than that of most mammalian tissues.Therefore,the amoeboid migration transition observed in these studies is actually induced by the synergistic effect of matrix stiffness and confinement.Since the stiffness of cell microenvironment has been reported to influence the cell migration in 2D substrate,the decoupling of stiffness and confinement effects is thus in need for elucidating the underlying mechanism of MAT.However,it is technically challenging to construct microchannels with physiologically relevant stiffness and channel size,where existing microchannel platforms with physiological relevance stiffness are all with>10μm channel width.Such size is too wide to mimic the physical confinement that migrating cancer cells confront in vivo,and also larger than the width of PDMS channel,in which the MAT of cancer cell was observed.Therefore,an in vitro cell migration platform,which could mimic both stiffness and confinement of the native physical microenvironment during cancer metastasis,could profoundly contribute to researches on cancer cell migration and cellular mechanotransduction.In this paper,we overcome the limitations of engineering soft materials in microscale by combining the collagen-alginate hydrogel with photolithography.This enables us to improve the accuracy of molded microchannel,and thus successfully construct a 3D microchannel platform,which matches the stiffness and width ranges of native environmental confinement that migrating cancer cells confront in vivo.The stiffness(0.3~20 kPa),confinement(channel width:3.5~14μm)and the adhesion ligand density of the microchannel can be tuned independently.Interestingly,using this platform,we observed that the migration speed of cancer cell is influenced by the synergistic effect of channel stiffness and width,and the increasing stiffness reverses the effect of channel width on the migration speed of cancer cells.In addition,MAT has a strong correlation with the channel stiffness.These findings make us reconsider the widely accepted hypothesis:physical confinement can induce MAT.Actually,this transition can only occur in stiff confined microenvironment not in soft one.For soft microchannels,the compliance of the channel walls could cause little cell/nucleus deformation,and the MAT could not be induced.To further investigate the mechanism of MAT,we developed a computational model to simulate the effect of nucleus deformation on MAT.With the model,we found that deforming the cell nuclear by decreasing the nucleus stiffness will reduce the cellmigration speed.This implies that nuclear stiffness plays an important role in the regulation of cancer migration speed and thus MAT in microchannels.The effect of channel stiffness on MAT and migration speed as observed in our experiment could partially explain previous findings reported in the literature,where the increasing matrix stiffness of tumor microenvironment promotes cancer metastasis.Our observations thus highlight the critical role of cell nuclear deformation not only in MAT,but also in regulating cellular mechanotransduction and cell-ECM interactions.This developed platform is capable of mimicking the native physical microenvironment during metastasis,providing a powerful tool for high-throughput screening applications and investigating the interaction between cancer migration and biophysical microenvironment.展开更多
Recommendation system can greatly alleviate the "information overload" in the big data era. Existing recommendation methods, however, typically focus on predicting missing rating values via analyzing user-it...Recommendation system can greatly alleviate the "information overload" in the big data era. Existing recommendation methods, however, typically focus on predicting missing rating values via analyzing user-item dualistic relationship, which neglect an important fact that the latent interests of users can influence their rating behaviors. Moreover, traditional recommendation methods easily suffer from the high dimensional problem and cold-start problem. To address these challenges, in this paper, we propose a PBUED(PLSA-Based Uniform Euclidean Distance) scheme, which utilizes topic model and uniform Euclidean distance to recommend the suitable items for users. The solution first employs probabilistic latent semantic analysis(PLSA) to extract users' interests, users with different interests are divided into different subgroups. Then, the uniform Euclidean distance is adopted to compute the users' similarity in the same interest subset; finally, the missing rating values of data are predicted via aggregating similar neighbors' ratings. We evaluate PBUED on two datasets and experimental results show PBUED can lead to better predicting performance and ranking performance than other approaches.展开更多
The single-chain elasticity of a completely unfolded protein （027）8, modules of human cardiac titin） is studied in different liquid environments by the atomic force microscopy （AFM）-based single molecule force sp...The single-chain elasticity of a completely unfolded protein （027）8, modules of human cardiac titin） is studied in different liquid environments by the atomic force microscopy （AFM）-based single molecule force spectroscopy （SMFS）. The experimental results show that there is a clear deviation between the force curves obtained in the aqueous and nonaqueous environments. Such a deviation can be attributed to the additional energy consumed by the rearrangement of the bound water molecules around the chain of the completely unfolded （I27）s chain upon stretching in aqueous solution, which is very similar to the partial dehydration process from a denatured/unfolded to a native/folded protein. Through the analysis of the free energy changes involved in protein folding, we conclude that it is due to the weak disturbance of water molecules and the special backbone structures of proteins that the self-assembly of proteins can be achieved in physiological conditions. We speculate that water is likely to be an important criterion for the selection of self-assembling macromolecules in the prebiotic chemical evolution.展开更多
针对工程实践中影像数据坐标系转换以及线上裁切的需求,基于对坐标系转换模型的理论研究和影像数据线上裁切方法的深入探索,采用平面四参数模型对影像数据进行平面坐标系转换,采用ArcGIS Server SOE技术对影像服务进行扩展开发的方法满...针对工程实践中影像数据坐标系转换以及线上裁切的需求,基于对坐标系转换模型的理论研究和影像数据线上裁切方法的深入探索,采用平面四参数模型对影像数据进行平面坐标系转换,采用ArcGIS Server SOE技术对影像服务进行扩展开发的方法满足影像数据线上裁切需求,利用Arc Map 10.1作为数据处理平台,成功对沈阳市2013、2015和2017年的影像数据实现平面坐标系向CGCS2000的转换,利用Visual Studio 2010和ArcGIS10.1作为开发平台,扩展开发影像服务的功能接口,实现了影像数据的在线裁切。展开更多
针对工程实践中不同坐标系下DWG数据相互变换的实际需要,通过对DWG数据存储组织结构以及AutoCAD.NET API的深入研究,采用平面四参数转换方法,基于Visual Studio 2010和AutoCAD 2008开发平台,成功开发了DWG数据坐标变换程序。以沈阳市1∶...针对工程实践中不同坐标系下DWG数据相互变换的实际需要,通过对DWG数据存储组织结构以及AutoCAD.NET API的深入研究,采用平面四参数转换方法,基于Visual Studio 2010和AutoCAD 2008开发平台,成功开发了DWG数据坐标变换程序。以沈阳市1∶500比例尺、1954北京坐标系的DWG数据为例,实现了不同坐标系下DWG数据的互相变换,并对变换后的数据进行了要素检查和精度分析。结果证明,采用基于AutoCAD.NET API二次开发的技术能够很好地满足DWG数据在不同坐标系下互相变换的应用需求,大大地节省了工作时间,提高了工作效率。展开更多
Polycomb group （PCG） complexes are epigenetic regulatory complexes that conduct transcriptional repression of target genes via modifying the chromatin. The two best characterized forms of PCG complexes, polycomb rep...Polycomb group （PCG） complexes are epigenetic regulatory complexes that conduct transcriptional repression of target genes via modifying the chromatin. The two best characterized forms of PCG complexes, polycomb repressive complexes 1 and 2 （PRC1 and PRC2）, are required for maintaining the sternness of embryonic stem cells and many types of adult stem cells. The spectra of target genes for PRCs are dynamically changing with cell differentiation, which is essential for proper decisions on cell fate during developmental processes, Chromobox （CBX） family proteins are canonical components in PRC1, responsible for targeting PRC1 to the chromatin. Recent studies highlight the function specifications among CBX family members in undifferentiated and differentiated stem cells, which reveal the interplay between compositional diversity and functional specificity of PRCI. In this review, we summarize the current knowledge about targeting and functional mechanisms of PRCs, emphasizing the recent breakthroughs related to CBX proteins under a number of physiological and pathological conditions.展开更多
Lung cancer is associated with a heavy cancer-related burden in terms of patients’physical and mental health worldwide.Two randomized controlled trials,the US-National Lung Screening Trial(NLST)and Nederlands-Leuvens...Lung cancer is associated with a heavy cancer-related burden in terms of patients’physical and mental health worldwide.Two randomized controlled trials,the US-National Lung Screening Trial(NLST)and Nederlands-Leuvens Longkanker Screenings Onderzoek(NELSON),indicated that low-dose CT(LDCT)screening results in a statistically significant decrease in mortality in patients with lung cancer,LDCT has become the standard approach for lung cancer screening.However,many issues in lung cancer screening remain unresolved,such as the screening criteria,high false-positive rate,and radiation exposure.This review first summarizes recent studies on lung cancer screening from the US,Europe,and Asia,and discusses risk-based selection for screening and the related issues.Second,an overview of novel techniques for the differential diagnosis of pulmonary nodules,including artificial intelligence and molecular biomarker-based screening,is presented.Third,current explorations of strategies for suspected malignancy are summarized.Overall,this review aims to help clinicians understand recent progress in lung cancer screening and alleviate the burden of lung cancer.展开更多
AIM： To investigate the selective tropism of liver stem cells to hepatocellular carcinoma （HCC） in an animal model and its feasibility as a vector to deliver therapeutic genes for targeted therapy of HCC.METHODS： ...AIM： To investigate the selective tropism of liver stem cells to hepatocellular carcinoma （HCC） in an animal model and its feasibility as a vector to deliver therapeutic genes for targeted therapy of HCC.METHODS： WB-F344, a kind of rat liver stem cell, was infected with recombinant virus to establish a cell line with stable, high-level expressing enhanced green fluorescent protein （EGFP）. An animal model of HCC in Wistar rats was established by implanting HCC cells （CBRH7919） combined with an immunosuppressive drug. EGFP labeled liver stern cells were injected into caudal veins of the animals and distribution was observed at different time points after injection. SDF-1 and c-kit expression in non-tumor liver and tumor tissue were analysed by immunohistochemistry for the relationshiop between the expression and migration of liver stem cells. Furthermore, hepatic stern cells were injected via the portal vein, hepatic artery, caudal vein, or directly into the pericancerous liver tissue, respectively, and effects on migration, localization, and proliferation of the hepatic stern cells within the tumor tissue were observed and analyzed.RESULTS： Recombinant adenovirus could deliver the EGFP gene to hepatic stem cells. A new stem cell line, named WB-EGFP, was established that stably expressed EGFP. WB-EGFP cells still showed selective tropism towards HCC and EGFP expression was stable in vivo. According to immunohistochemistry results, SDF-1 may not be related to the mechanisms of tropism of hepatic stem cells. Different application sites affected the distribution of liver stem cells. Injection via the portal vein was superior with regard to selective migration, localization, and proliferation of the hepatic stem cells within the tumor tissue.CONCLUSION： Liver stem cells have the biological behavior of selective migration to HCC in vivo and they could localize and proliferate within HCC tissue stably expressing the target gene. Liver stem cells are a potential tool for a targeted gene therapy of HCC.展开更多
BACKGROUND Acute pancreatitis(AP)is an inflammatory disease in which the regulatory pathway is complex and not well understood.Soluble suppression of tumorigenicity 2(sST2)protein receptor functions as a decoy recepto...BACKGROUND Acute pancreatitis(AP)is an inflammatory disease in which the regulatory pathway is complex and not well understood.Soluble suppression of tumorigenicity 2(sST2)protein receptor functions as a decoy receptor for interleukin(IL)-33 to prevent IL-33/suppression of tumorigenicity 2L(ST2L)-pathwaymediated T helper(Th)2 immune responses.AIM To investigate the role of sST2 in AP.METHODS We assessed the association between sST2 and severity of AP in 123 patients enrolled in this study.The serum levels of sST2,C-reactive protein(CRP)and Th1-and Th2-related cytokines,including interferon(IFN)-γ,tumor necrosis factor(TNF)-α,IL-2,IL-4,IL-5 and IL-13,were measured by highly sensitive ELISA,and the severity of AP in patients was evaluated by the 2012 Atlanta Classification Criteria.RESULTS Serum sST2 levels were significantly increased in AP patients,and further,these levels were significantly elevated in severe AP(SAP)patients compared to moderately severe AP(MSAP)and mild AP(MAP)patients.Logistic regression showed sST2 was a predictor of SAP[odds ratio(OR):1.003(1.001–1.006),P=0.000].sST2 cutoff point was 1190 pg/mL,and sST2 above this cutoff was associated with SAP.sST2 was also a predictor of any organ failure and mortality during AP[OR:1.006(1.003–1.009),P=0.000,OR:1.002(1.001–1.004),P=0.012,respectively].Additionally,the Th1-related cytokines IFN-γand TNF-αin the SAP group were higher and the Th2-related cytokine IL-4 in the SAP group was significantly lower than those in MSAP and MAP groups.CONCLUSION sST2 may be used as a novel inflammatory marker in predicting AP severity and may regulate the function and differentiation of IL-33/ST2-mediated Th1 and Th2 Lymphocytes in AP homeostasis.展开更多
To clarify the transformation mechanism of secondary phase and the mechanism of intergranular corrosion in laser welding Ni-based alloy (Hastelloy C-276)/304 stainless steel with filler wire,the secondary phase was an...To clarify the transformation mechanism of secondary phase and the mechanism of intergranular corrosion in laser welding Ni-based alloy (Hastelloy C-276)/304 stainless steel with filler wire,the secondary phase was analyzed by electron probe micro-analysis (EPMA) and transmission electron microscopy (TEM).The evaluation of intergranular corrosion resistance of the welded joints was conducted by double-loop electrochemical potentiokinetic reactivation(DL-EPR) method,and at the same time the chemical compositions of the corrosion surface were analyzed by energy-dispersive spectrometry (EDS).The results show that p phase has complete coherence relationship withμphase,and the coherent relationship is described as[001]p//■and[430]p//[0001]μ.Theμphase is rapidly transformed from p phase,which is the inhomogeneous phase transformation.The transformation of secondary phase will increase the susceptibility to intergranular corrosion.Therefore,the transformation of secondary phase should be avoided in the welding process.展开更多
Large-strain deformation by single electroplastic rolling （EPR） was imposed on AZ31 magnesium alloy strips. During EPR at low temperature （150-250℃）, numerous twins formed in the alloy. After EPR at a high temper...Large-strain deformation by single electroplastic rolling （EPR） was imposed on AZ31 magnesium alloy strips. During EPR at low temperature （150-250℃）, numerous twins formed in the alloy. After EPR at a high temperature （350℃）, the number of twins reduced and some dynamic recrystallization （DRX） grains formed at grain boundaries and twinned regions. The synergic thermal and athermal effects generated by electropulsing, which promoted dislocation motion, induced a few small DRX grains, and ductile bandings were mainly re- sponsible for large-strain deformation during EPR. The inclination angle of the basal pole stemmed from the counterbalance of the inclina- tion direction of the basal pole between the DRX grains and deformed coarse grains.展开更多
文摘BACKGROUND Acute lung injury(ALI)is a common and life-threatening complication of severe acute pancreatitis(SAP).There are currently limited effective treatment options for SAP and associated ALI.Calycosin(Cal),a bioactive constituent extracted from the medicinal herb Radix Astragali exhibits potent anti-inflammatory properties,but its effect on SAP and associated ALI has yet to be determined.AIM To identify the roles of Cal in SAP-ALI and the underlying mechanism.METHODS SAP was induced via two intraperitoneal injections of L-arg(4 g/kg)and Cal(25 or 50 mg/kg)were injected 1 h prior to the first L-arg challenge.Mice were sacrificed 72 h after the induction of SAP and associated ALI was examined histologically and biochemically.An in vitro model of lipopolysaccharide(LPS)-induced ALI was established using A549 cells.Immunofluorescence analysis and western blot were evaluated in cells.Molecular docking analyses were conducted to examine the interaction of Cal with HMGB1.RESULTS Cal treatment substantially reduced the serum amylase levels and alleviated histopathological injury associated with SAP and ALI.Neutrophil infiltration and lung tissue levels of neutrophil mediator myeloperoxidase were reduced in line with protective effects of Cal against ALI in SAP.Cal treatment also attenuated the serum levels and mRNA expression of pro-inflammatory cytokines tumor necrosis factor-α,interleukin-6,IL-1β,HMGB1 and chemokine(CXC motif)ligand 1 in lung tissue.Immunofluorescence and western blot analyses showed that Cal treatment markedly suppressed the expression of HMGB1 and phosphorylated nuclear factor-kappa B(NF-κB)p65 in lung tissues and an in vitro model of LPSinduced ALI in A549 cells suggesting a role for HGMB1 in the pathogenesis of ALI.Furthermore,molecular docking analysis provided evidence for the direct interaction of Cal with HGMB1.CONCLUSION Cal protects mice against L-arg-induced SAP and associated ALI by attenuating local and systemic neutrophil infiltration and inflammatory response via inhibition of HGMB1 and the NF-κB signaling pathway.
基金financially supported by the National Natural Science Foundation of China ( 11532009, 11602191,21775117)the General Financial Grant from the China Postdoctoral Science Foundation ( 2016M592773)the High Level Returned Overseas Students Foundation ( [2018]642)
文摘The migration mode transition of cancer cell enhances its invasive capability and the drug resistance,where physical confinement of cell microenvironment has been revealed to induce the mesenchymal-amoeboid transition(MAT).However,most existing studies are performed in PDMS microchannels,of which the stiffness is much higher than that of most mammalian tissues.Therefore,the amoeboid migration transition observed in these studies is actually induced by the synergistic effect of matrix stiffness and confinement.Since the stiffness of cell microenvironment has been reported to influence the cell migration in 2D substrate,the decoupling of stiffness and confinement effects is thus in need for elucidating the underlying mechanism of MAT.However,it is technically challenging to construct microchannels with physiologically relevant stiffness and channel size,where existing microchannel platforms with physiological relevance stiffness are all with>10μm channel width.Such size is too wide to mimic the physical confinement that migrating cancer cells confront in vivo,and also larger than the width of PDMS channel,in which the MAT of cancer cell was observed.Therefore,an in vitro cell migration platform,which could mimic both stiffness and confinement of the native physical microenvironment during cancer metastasis,could profoundly contribute to researches on cancer cell migration and cellular mechanotransduction.In this paper,we overcome the limitations of engineering soft materials in microscale by combining the collagen-alginate hydrogel with photolithography.This enables us to improve the accuracy of molded microchannel,and thus successfully construct a 3D microchannel platform,which matches the stiffness and width ranges of native environmental confinement that migrating cancer cells confront in vivo.The stiffness(0.3~20 kPa),confinement(channel width:3.5~14μm)and the adhesion ligand density of the microchannel can be tuned independently.Interestingly,using this platform,we observed that the migration speed of cancer cell is influenced by the synergistic effect of channel stiffness and width,and the increasing stiffness reverses the effect of channel width on the migration speed of cancer cells.In addition,MAT has a strong correlation with the channel stiffness.These findings make us reconsider the widely accepted hypothesis:physical confinement can induce MAT.Actually,this transition can only occur in stiff confined microenvironment not in soft one.For soft microchannels,the compliance of the channel walls could cause little cell/nucleus deformation,and the MAT could not be induced.To further investigate the mechanism of MAT,we developed a computational model to simulate the effect of nucleus deformation on MAT.With the model,we found that deforming the cell nuclear by decreasing the nucleus stiffness will reduce the cellmigration speed.This implies that nuclear stiffness plays an important role in the regulation of cancer migration speed and thus MAT in microchannels.The effect of channel stiffness on MAT and migration speed as observed in our experiment could partially explain previous findings reported in the literature,where the increasing matrix stiffness of tumor microenvironment promotes cancer metastasis.Our observations thus highlight the critical role of cell nuclear deformation not only in MAT,but also in regulating cellular mechanotransduction and cell-ECM interactions.This developed platform is capable of mimicking the native physical microenvironment during metastasis,providing a powerful tool for high-throughput screening applications and investigating the interaction between cancer migration and biophysical microenvironment.
基金supported in part by the National High‐tech R&D Program of China (863 Program) under Grant No. 2013AA102301technological project of Henan province (162102210214)
文摘Recommendation system can greatly alleviate the "information overload" in the big data era. Existing recommendation methods, however, typically focus on predicting missing rating values via analyzing user-item dualistic relationship, which neglect an important fact that the latent interests of users can influence their rating behaviors. Moreover, traditional recommendation methods easily suffer from the high dimensional problem and cold-start problem. To address these challenges, in this paper, we propose a PBUED(PLSA-Based Uniform Euclidean Distance) scheme, which utilizes topic model and uniform Euclidean distance to recommend the suitable items for users. The solution first employs probabilistic latent semantic analysis(PLSA) to extract users' interests, users with different interests are divided into different subgroups. Then, the uniform Euclidean distance is adopted to compute the users' similarity in the same interest subset; finally, the missing rating values of data are predicted via aggregating similar neighbors' ratings. We evaluate PBUED on two datasets and experimental results show PBUED can lead to better predicting performance and ranking performance than other approaches.
基金financially supported by the National Natural Science Foundation of China(Nos.21574106 and 21604074)the Sichuan Province Youth Science and Technology Innovation Team(Nos.2016TD0026 and 2017JQ0009)
文摘The single-chain elasticity of a completely unfolded protein （027）8, modules of human cardiac titin） is studied in different liquid environments by the atomic force microscopy （AFM）-based single molecule force spectroscopy （SMFS）. The experimental results show that there is a clear deviation between the force curves obtained in the aqueous and nonaqueous environments. Such a deviation can be attributed to the additional energy consumed by the rearrangement of the bound water molecules around the chain of the completely unfolded （I27）s chain upon stretching in aqueous solution, which is very similar to the partial dehydration process from a denatured/unfolded to a native/folded protein. Through the analysis of the free energy changes involved in protein folding, we conclude that it is due to the weak disturbance of water molecules and the special backbone structures of proteins that the self-assembly of proteins can be achieved in physiological conditions. We speculate that water is likely to be an important criterion for the selection of self-assembling macromolecules in the prebiotic chemical evolution.
基金supported by Major Special Projects of Gansu Province,China(No.21ZD4WA017)University Industry Transformation Promotion Project of Gansu Province,China(No.2020C-11)+1 种基金the Program of“Science and Technology International Cooperation Demonstrative Base of Metal Surface Engineering along the Silk Road”,China(No.2017D01003)the National Natural Science Foundation of China(No.51901093)。
文摘针对工程实践中影像数据坐标系转换以及线上裁切的需求,基于对坐标系转换模型的理论研究和影像数据线上裁切方法的深入探索,采用平面四参数模型对影像数据进行平面坐标系转换,采用ArcGIS Server SOE技术对影像服务进行扩展开发的方法满足影像数据线上裁切需求,利用Arc Map 10.1作为数据处理平台,成功对沈阳市2013、2015和2017年的影像数据实现平面坐标系向CGCS2000的转换,利用Visual Studio 2010和ArcGIS10.1作为开发平台,扩展开发影像服务的功能接口,实现了影像数据的在线裁切。
基金Project supported by the Fundamental Research Funds for the Central Universities from Lanzhou University (No.lzujbky-2014-87),China
文摘Polycomb group （PCG） complexes are epigenetic regulatory complexes that conduct transcriptional repression of target genes via modifying the chromatin. The two best characterized forms of PCG complexes, polycomb repressive complexes 1 and 2 （PRC1 and PRC2）, are required for maintaining the sternness of embryonic stem cells and many types of adult stem cells. The spectra of target genes for PRCs are dynamically changing with cell differentiation, which is essential for proper decisions on cell fate during developmental processes, Chromobox （CBX） family proteins are canonical components in PRC1, responsible for targeting PRC1 to the chromatin. Recent studies highlight the function specifications among CBX family members in undifferentiated and differentiated stem cells, which reveal the interplay between compositional diversity and functional specificity of PRCI. In this review, we summarize the current knowledge about targeting and functional mechanisms of PRCs, emphasizing the recent breakthroughs related to CBX proteins under a number of physiological and pathological conditions.
基金This study was supported by the China National Science Foundation(Grant Nos.82022048 and 81871893)the Key Project of Guangzhou Scientific Research Project(Grant No.201804020030).
文摘Lung cancer is associated with a heavy cancer-related burden in terms of patients’physical and mental health worldwide.Two randomized controlled trials,the US-National Lung Screening Trial(NLST)and Nederlands-Leuvens Longkanker Screenings Onderzoek(NELSON),indicated that low-dose CT(LDCT)screening results in a statistically significant decrease in mortality in patients with lung cancer,LDCT has become the standard approach for lung cancer screening.However,many issues in lung cancer screening remain unresolved,such as the screening criteria,high false-positive rate,and radiation exposure.This review first summarizes recent studies on lung cancer screening from the US,Europe,and Asia,and discusses risk-based selection for screening and the related issues.Second,an overview of novel techniques for the differential diagnosis of pulmonary nodules,including artificial intelligence and molecular biomarker-based screening,is presented.Third,current explorations of strategies for suspected malignancy are summarized.Overall,this review aims to help clinicians understand recent progress in lung cancer screening and alleviate the burden of lung cancer.
文摘AIM： To investigate the selective tropism of liver stem cells to hepatocellular carcinoma （HCC） in an animal model and its feasibility as a vector to deliver therapeutic genes for targeted therapy of HCC.METHODS： WB-F344, a kind of rat liver stem cell, was infected with recombinant virus to establish a cell line with stable, high-level expressing enhanced green fluorescent protein （EGFP）. An animal model of HCC in Wistar rats was established by implanting HCC cells （CBRH7919） combined with an immunosuppressive drug. EGFP labeled liver stern cells were injected into caudal veins of the animals and distribution was observed at different time points after injection. SDF-1 and c-kit expression in non-tumor liver and tumor tissue were analysed by immunohistochemistry for the relationshiop between the expression and migration of liver stem cells. Furthermore, hepatic stern cells were injected via the portal vein, hepatic artery, caudal vein, or directly into the pericancerous liver tissue, respectively, and effects on migration, localization, and proliferation of the hepatic stern cells within the tumor tissue were observed and analyzed.RESULTS： Recombinant adenovirus could deliver the EGFP gene to hepatic stem cells. A new stem cell line, named WB-EGFP, was established that stably expressed EGFP. WB-EGFP cells still showed selective tropism towards HCC and EGFP expression was stable in vivo. According to immunohistochemistry results, SDF-1 may not be related to the mechanisms of tropism of hepatic stem cells. Different application sites affected the distribution of liver stem cells. Injection via the portal vein was superior with regard to selective migration, localization, and proliferation of the hepatic stem cells within the tumor tissue.CONCLUSION： Liver stem cells have the biological behavior of selective migration to HCC in vivo and they could localize and proliferate within HCC tissue stably expressing the target gene. Liver stem cells are a potential tool for a targeted gene therapy of HCC.
基金Supported by Henan Province Education Department for Henan Province University Key Scientific Research Project,No.20A320018 and No.20A320064。
文摘BACKGROUND Acute pancreatitis(AP)is an inflammatory disease in which the regulatory pathway is complex and not well understood.Soluble suppression of tumorigenicity 2(sST2)protein receptor functions as a decoy receptor for interleukin(IL)-33 to prevent IL-33/suppression of tumorigenicity 2L(ST2L)-pathwaymediated T helper(Th)2 immune responses.AIM To investigate the role of sST2 in AP.METHODS We assessed the association between sST2 and severity of AP in 123 patients enrolled in this study.The serum levels of sST2,C-reactive protein(CRP)and Th1-and Th2-related cytokines,including interferon(IFN)-γ,tumor necrosis factor(TNF)-α,IL-2,IL-4,IL-5 and IL-13,were measured by highly sensitive ELISA,and the severity of AP in patients was evaluated by the 2012 Atlanta Classification Criteria.RESULTS Serum sST2 levels were significantly increased in AP patients,and further,these levels were significantly elevated in severe AP(SAP)patients compared to moderately severe AP(MSAP)and mild AP(MAP)patients.Logistic regression showed sST2 was a predictor of SAP[odds ratio(OR):1.003(1.001–1.006),P=0.000].sST2 cutoff point was 1190 pg/mL,and sST2 above this cutoff was associated with SAP.sST2 was also a predictor of any organ failure and mortality during AP[OR:1.006(1.003–1.009),P=0.000,OR:1.002(1.001–1.004),P=0.012,respectively].Additionally,the Th1-related cytokines IFN-γand TNF-αin the SAP group were higher and the Th2-related cytokine IL-4 in the SAP group was significantly lower than those in MSAP and MAP groups.CONCLUSION sST2 may be used as a novel inflammatory marker in predicting AP severity and may regulate the function and differentiation of IL-33/ST2-mediated Th1 and Th2 Lymphocytes in AP homeostasis.
基金The authors would like to acknowledge the financial support from National Key Research and Development Program of China(2018YFB1107801 and 2018YFB1107802)Science Fund for Creative Research Groups of NSFC(51621064)+1 种基金National Natural Science Foundation of China(51790172)Fundamental Research Funds for the Central University(DUT19LAB06).
文摘To clarify the transformation mechanism of secondary phase and the mechanism of intergranular corrosion in laser welding Ni-based alloy (Hastelloy C-276)/304 stainless steel with filler wire,the secondary phase was analyzed by electron probe micro-analysis (EPMA) and transmission electron microscopy (TEM).The evaluation of intergranular corrosion resistance of the welded joints was conducted by double-loop electrochemical potentiokinetic reactivation(DL-EPR) method,and at the same time the chemical compositions of the corrosion surface were analyzed by energy-dispersive spectrometry (EDS).The results show that p phase has complete coherence relationship withμphase,and the coherent relationship is described as[001]p//■and[430]p//[0001]μ.Theμphase is rapidly transformed from p phase,which is the inhomogeneous phase transformation.The transformation of secondary phase will increase the susceptibility to intergranular corrosion.Therefore,the transformation of secondary phase should be avoided in the welding process.
基金support from the National Natural Science Foundation of China (Nos. 51104016 and 50571048)the National High Technology Research and Development Program of China (No. 2013AA031301)the fund of the State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals (No. SKL-SPM-201204)
文摘Large-strain deformation by single electroplastic rolling （EPR） was imposed on AZ31 magnesium alloy strips. During EPR at low temperature （150-250℃）, numerous twins formed in the alloy. After EPR at a high temperature （350℃）, the number of twins reduced and some dynamic recrystallization （DRX） grains formed at grain boundaries and twinned regions. The synergic thermal and athermal effects generated by electropulsing, which promoted dislocation motion, induced a few small DRX grains, and ductile bandings were mainly re- sponsible for large-strain deformation during EPR. The inclination angle of the basal pole stemmed from the counterbalance of the inclina- tion direction of the basal pole between the DRX grains and deformed coarse grains.
