[Objectives]This study was conducted to establish a liquid chromatography-tandem mass spectrometry method for the determination of coumoxystrobin residue in milk.[Methods]A sample was ultrasonically extracted with ace...[Objectives]This study was conducted to establish a liquid chromatography-tandem mass spectrometry method for the determination of coumoxystrobin residue in milk.[Methods]A sample was ultrasonically extracted with acetonitrile,purified by a solid phase extraction column,concentrated by nitrogen blowing,and tested on a machine.[Results]In the range of 0.01-10.00 mg/kg,the linear relationship of coumoxystrobin was good.The linear equation was y=5045.96x+935.332,r^(2)=0.999.The detection limit was 0.002 mg/kg,and the quantitation limit was 0.006 mg/kg.The method has good stability,high precision,and the detection limit can meet the limit requirement of coumoxystrobin in GB 2763-2019.[Conclusions]This study can provide technical support for the supervision and monitoring of coumoxystrobin.展开更多
Imidaclothiz residue in tea was determined by high performance liquid chromatography（ HPLC）,using different extractants including hexane,acetonitrile,acetone,hexane-acetonitrile（ 1∶ 1）,acetonitrile-acetone（ 1∶ ...Imidaclothiz residue in tea was determined by high performance liquid chromatography（ HPLC）,using different extractants including hexane,acetonitrile,acetone,hexane-acetonitrile（ 1∶ 1）,acetonitrile-acetone（ 1∶ 1） and hexane-ethyl acetate（ 1∶ 1）. The results indicated that all the extractants displayed excellent extraction capacities of imidaclothiz residue in tea and insignificant interference on the accuracy. Under the optimized extraction volume（ 20 ml）,the recovery values were in the ranges of 82. 3%-100. 7%,85. 8%-101. 1%,85. 9%-95. 2%,82. 3%-101. 3%,82. 4%-100. 5% and 88. 6%-102. 3%,respectively,with the relative standard deviations smaller than 10%. Moreover,mixed solvent showed improved extraction capacity,and the highest extraction capacity and promoted stability were approached by using hexane-ethyl acetate（ 1∶ 1） as coextractants.展开更多
In December 2019,a novel coronavirus was first reported in Wuhan,China.1 It was named by the World Health Organization as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and is responsible for coronavirus d...In December 2019,a novel coronavirus was first reported in Wuhan,China.1 It was named by the World Health Organization as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and is responsible for coronavirus disease 2019(COVID-19).Up to 28 February 2020,79,394 cases have been confirmed according to China’s National Health Commission.Outside China,the virus has spread rapidly to over 36 countries and territories.展开更多
The liver has been characterized as a frontline lymphoid organ with complex immunological features such as liver immunity and liver tolerance. Liver tolerance plays an important role in liver diseases including acute ...The liver has been characterized as a frontline lymphoid organ with complex immunological features such as liver immunity and liver tolerance. Liver tolerance plays an important role in liver diseases including acute inflammation, chronic infection, autoimmune disease, and tumors. The liver contains a large proportion of natural killer （NK） cells, which exhibit heterogeneity in phenotypic and functional characteristics. NK cell activation, well known for its role in the immune surveillance against tumor and pathogen-infected cells, depends on the balance between numerous activating and inhibitory signals. In addition to the innate direct ＂killer＂ functions, NK cell activity contributes to regulate innate and adaptive immunity （helper or regulator）. Under the setting of liver diseases, NK cells are of great importance for stimulating or inhibiting immune responses, leading to either immune activation or immune tolerance. Here, we focus on the relationship between NK cell biology, such as their phenotypic features and functional diversity, and liver diseases.展开更多
Gut-derived bacterial products contribute to liver inflammation and injury during chronic hepatitis B virus infection;however,the underlying mechanisms remain obscure.In this study,hepatitis B surface antigen transgen...Gut-derived bacterial products contribute to liver inflammation and injury during chronic hepatitis B virus infection;however,the underlying mechanisms remain obscure.In this study,hepatitis B surface antigen transgenic(HBs-Tg)mice and their wild-type(WT)control C57BL/6 mice were injected with CpG-oligodeoxynucleotides(ODNs)to mimic the translocation of gut microbial products into the systemic circulation.We found that,compared with the WT mice,the HBs-Tg mice were oversensitive to CpG-ODN-induced liver injury,which was dependent on natural killer T(NKT)cells.CpG-ODN injection enhanced the expression of Fas ligand(FasL)on NKT cells.In addition,hepatocytes from the HBs-Tg mice expressed higher levels of Fas than did those from the WT mice,which was further augmented by CpG-ODN.Interaction of Fas and FasL was involved in the cytotoxicity of NKT cells against hepatocytes in the HBs-Tg mice.Moreover,Kupffer cells in the HBs-Tg mice expressed higher levels of CD205 and produced greater amounts of interleukin(IL)-12 than did those in the WT mice.Finally,the depletion of Kupffer cells,neutralization of IL-12 or specific silencing of CD205 on Kupffer cells significantly inhibited CpG-ODN-induced liver injury and NKT activation in the HBs-Tg mice.Our data suggest that CD205-expressing Kupffer cells respond to CpG-ODNs and subsequently release IL-12 to promote NKT cell activation.Activated NKT cells induce liver damage through the Fas signaling pathway in HBs-Tg mice.展开更多
The lymphatic system is important in mounting an immune response to foreign antigens and tumors in humans and animal models. The liver produces a large amount of lymph, and its lymphatic system is divided into three m...The lymphatic system is important in mounting an immune response to foreign antigens and tumors in humans and animal models. The liver produces a large amount of lymph, and its lymphatic system is divided into three major components： the portal, sublobular and superficial lymphatic vessels. Despite the fact that mice are the most commonly used laboratory animals, detailed descriptions of the anatomical location and function of the lymph nodes （LNs） that drain the liver are surprisingly absent. In this study, we found that the portal and celiac LNs adjacent to mouse liver were stained with Evans blue within 5-8 min. Enhanced green fluorescence protein （EGFP）-positive cells from the liver also drained into the two aforementioned LNs. These data indicate that the portal and celiac LNs drain the mouse liver. Lymphadenectomy of the identified liver-draining LNs resulted in hepatitis B virus （HBV） persistence in immunocompetent mice compared with the sham group. In addition, the frequencies of CD8＋ T cells and dendritic cells （DCs） increased significantly in the liver-draining LNs after hydrodynamic injection of HBV plasmid. Liver-draining LN cells in HBV plasmid-injected mice also showed significant antigen-specific proliferation in response to stimulation with recombinant hepatitis B core antigen in vitro. Adoptive transfer of these cells into Rag1-/- mice induced a reduction in the serum concentration of hepatitis B surface antigen （HBsAg） compared to liver-draining LN cells in uninjected mice. Altogether our data characterize the liver-draining LNs and provide evidence that the liver-draining LNs induce an anti-HBV-specific immune response responsible for HBV clearance.展开更多
基金Special Fund for Innovation Capacity Building of Scientific Research Institutions(QKHFQ[2019]4001)Science and Technology Program of Guizhou Province(QKHZC[2019]2451-8-3).
文摘[Objectives]This study was conducted to establish a liquid chromatography-tandem mass spectrometry method for the determination of coumoxystrobin residue in milk.[Methods]A sample was ultrasonically extracted with acetonitrile,purified by a solid phase extraction column,concentrated by nitrogen blowing,and tested on a machine.[Results]In the range of 0.01-10.00 mg/kg,the linear relationship of coumoxystrobin was good.The linear equation was y=5045.96x+935.332,r^(2)=0.999.The detection limit was 0.002 mg/kg,and the quantitation limit was 0.006 mg/kg.The method has good stability,high precision,and the detection limit can meet the limit requirement of coumoxystrobin in GB 2763-2019.[Conclusions]This study can provide technical support for the supervision and monitoring of coumoxystrobin.
基金Supported by Special Fund for International S&T Cooperation Project of China(2015DFA41280)Guizhou Science and Technology Program(QKHWGZ[2015]7001)
文摘Imidaclothiz residue in tea was determined by high performance liquid chromatography（ HPLC）,using different extractants including hexane,acetonitrile,acetone,hexane-acetonitrile（ 1∶ 1）,acetonitrile-acetone（ 1∶ 1） and hexane-ethyl acetate（ 1∶ 1）. The results indicated that all the extractants displayed excellent extraction capacities of imidaclothiz residue in tea and insignificant interference on the accuracy. Under the optimized extraction volume（ 20 ml）,the recovery values were in the ranges of 82. 3%-100. 7%,85. 8%-101. 1%,85. 9%-95. 2%,82. 3%-101. 3%,82. 4%-100. 5% and 88. 6%-102. 3%,respectively,with the relative standard deviations smaller than 10%. Moreover,mixed solvent showed improved extraction capacity,and the highest extraction capacity and promoted stability were approached by using hexane-ethyl acetate（ 1∶ 1） as coextractants.
基金from the National Natural Science Foundation of China(#81788101 and#81771685)Chinese Academy of Sciences(XDB29030000)the Emergency Project of Anhui Medical University of Science and Technology(YJGG202002).
文摘In December 2019,a novel coronavirus was first reported in Wuhan,China.1 It was named by the World Health Organization as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and is responsible for coronavirus disease 2019(COVID-19).Up to 28 February 2020,79,394 cases have been confirmed according to China’s National Health Commission.Outside China,the virus has spread rapidly to over 36 countries and territories.
基金This work was supported by grants from the National Natural Science Foundation of China （Nos. 81771685, 91429303, 31390433, 81761128013, and 91542000） and Ministry of Science and Technology of China （973 Basic Science Project, No. 2013CB944902）.
文摘The liver has been characterized as a frontline lymphoid organ with complex immunological features such as liver immunity and liver tolerance. Liver tolerance plays an important role in liver diseases including acute inflammation, chronic infection, autoimmune disease, and tumors. The liver contains a large proportion of natural killer （NK） cells, which exhibit heterogeneity in phenotypic and functional characteristics. NK cell activation, well known for its role in the immune surveillance against tumor and pathogen-infected cells, depends on the balance between numerous activating and inhibitory signals. In addition to the innate direct ＂killer＂ functions, NK cell activity contributes to regulate innate and adaptive immunity （helper or regulator）. Under the setting of liver diseases, NK cells are of great importance for stimulating or inhibiting immune responses, leading to either immune activation or immune tolerance. Here, we focus on the relationship between NK cell biology, such as their phenotypic features and functional diversity, and liver diseases.
基金supported by the Natural Science Foundation of China(81571540,91429303,81361120388,31390433 and 81302525)the National Science&Technology Major Projects(2013ZX10002002-002)the open project of the CAS Key Laboratory of Innate Immunity and Chronic Disease(KLIICD-201509).
文摘Gut-derived bacterial products contribute to liver inflammation and injury during chronic hepatitis B virus infection;however,the underlying mechanisms remain obscure.In this study,hepatitis B surface antigen transgenic(HBs-Tg)mice and their wild-type(WT)control C57BL/6 mice were injected with CpG-oligodeoxynucleotides(ODNs)to mimic the translocation of gut microbial products into the systemic circulation.We found that,compared with the WT mice,the HBs-Tg mice were oversensitive to CpG-ODN-induced liver injury,which was dependent on natural killer T(NKT)cells.CpG-ODN injection enhanced the expression of Fas ligand(FasL)on NKT cells.In addition,hepatocytes from the HBs-Tg mice expressed higher levels of Fas than did those from the WT mice,which was further augmented by CpG-ODN.Interaction of Fas and FasL was involved in the cytotoxicity of NKT cells against hepatocytes in the HBs-Tg mice.Moreover,Kupffer cells in the HBs-Tg mice expressed higher levels of CD205 and produced greater amounts of interleukin(IL)-12 than did those in the WT mice.Finally,the depletion of Kupffer cells,neutralization of IL-12 or specific silencing of CD205 on Kupffer cells significantly inhibited CpG-ODN-induced liver injury and NKT activation in the HBs-Tg mice.Our data suggest that CD205-expressing Kupffer cells respond to CpG-ODNs and subsequently release IL-12 to promote NKT cell activation.Activated NKT cells induce liver damage through the Fas signaling pathway in HBs-Tg mice.
基金This work was supported by the Ministry of Science and Technology of China （973 Basic Science Project 2013CB944902）, the Natural Science Foundation of China （Nos. 91029303, 31021061） and the National Science and Technology Major Projects （2013ZX10002002-002）. We thank Professor Pei-Jer Chen for providing the pAAV-HBV plasmid.
文摘The lymphatic system is important in mounting an immune response to foreign antigens and tumors in humans and animal models. The liver produces a large amount of lymph, and its lymphatic system is divided into three major components： the portal, sublobular and superficial lymphatic vessels. Despite the fact that mice are the most commonly used laboratory animals, detailed descriptions of the anatomical location and function of the lymph nodes （LNs） that drain the liver are surprisingly absent. In this study, we found that the portal and celiac LNs adjacent to mouse liver were stained with Evans blue within 5-8 min. Enhanced green fluorescence protein （EGFP）-positive cells from the liver also drained into the two aforementioned LNs. These data indicate that the portal and celiac LNs drain the mouse liver. Lymphadenectomy of the identified liver-draining LNs resulted in hepatitis B virus （HBV） persistence in immunocompetent mice compared with the sham group. In addition, the frequencies of CD8＋ T cells and dendritic cells （DCs） increased significantly in the liver-draining LNs after hydrodynamic injection of HBV plasmid. Liver-draining LN cells in HBV plasmid-injected mice also showed significant antigen-specific proliferation in response to stimulation with recombinant hepatitis B core antigen in vitro. Adoptive transfer of these cells into Rag1-/- mice induced a reduction in the serum concentration of hepatitis B surface antigen （HBsAg） compared to liver-draining LN cells in uninjected mice. Altogether our data characterize the liver-draining LNs and provide evidence that the liver-draining LNs induce an anti-HBV-specific immune response responsible for HBV clearance.
