Background：Pyroptosis is the term for caspase-l-dependent cell death associated with pro-inflammatory cytokines.The role of alveolar macrophage （AM） pyroptosis in the pathogenesis of the acute lung injury and acute...Background：Pyroptosis is the term for caspase-l-dependent cell death associated with pro-inflammatory cytokines.The role of alveolar macrophage （AM） pyroptosis in the pathogenesis of the acute lung injury and acute respiratory distress syndrome （ALI/ARDS） remains unclear.Methods：C57BL/6 wild-type mice were assigned to sham,lipopolysaccharide （LPS） ＋ vehicle,LPS ＋ acetyl-tyrosyl-valyl-alanyl-aspartyl-chloromethylketone （Ac-YVAD-CMK） and LPS ＋ Z-Asp-Glu-Val-Asp-fluoromethylketone groups.Mice were given intraperitoneal （IP） injections of LPS.Drugs were IP injected 1 h before LPS administration.Mice were sacrificed 16 h after LPS administration,and AMs were isolated.Western blot analysis for active caspase-1 and cleaved caspase-3,evaluation of lung injury and a cytokine release analysis were performed.AMs were treated with LPS and adenosine triphosphate （ATP）;caspase-l-dependent cell death was evaluated using flow cytometry;the apoptosis-associated speck-like protein containing a caspase recruitment domain （ASC） pyroptosomes were examined by immunofluorescence.Results：The expression of activated caspase-1 in AMs was enhanced following LPS challenge compared with the sham group.In the ex vivo study,the caspase-1/propidium iodide-positive cells,caspase-1 specks and ASC pyroptosomes were up-regulated in AMs following LPS/ATP stimulation.The specific caspase-1 inhibitor Ac-YVAD-CMK inhibited the activation of caspase-1 and pyroptotic cell death.Ac-YVAD-CMK also reduced the lung injury,pulmonary edema and total protein in bronchoalveolar lavage fluid （BALF）.In addition,Ac-YVAD-CMK significantly inhibited interleukin-β （IL-lβ） release both in serum and BALF and reduced the levels of IL-18,tumor necrosis factor-α （TNF-α）,High Mobility Group Box 1 （HMGB1） in BALF during LPS-induced ALI/ARDS.Conclusions：This study reported AM pyroptosis during LPS-induced ALI/ARDS in mice and has demonstrated that Ac-YVAD-CMK can prevent AM-induced pyroptosis and lung injury.These 展开更多
Objective： To test the influence of homocysteine on the production and activation of matrix metalloproteinase-2 （MMP-2） and tissue inhibitors of matrix metalloproteinase-2 （TIMP-2） and on cell migration of cultur...Objective： To test the influence of homocysteine on the production and activation of matrix metalloproteinase-2 （MMP-2） and tissue inhibitors of matrix metalloproteinase-2 （TIMP-2） and on cell migration of cultured rat vascular smooth muscle cells （VSMCs）. Also, to explore whether rosuvastatin can alter the abnormal secretion and activation of MMP-2 and TIMP-2 and migration of VSMCs induced by homocysteine. Methods： Rat VSMCs were incubated with different concentrations of homocysteine （50-5000 μmol/L）. Western blotting and gelatin zymography were used to investigate the expressions and activities of MMP-2 and TIMP-2 in VSMCs in culture medium when induced with homocysteine for 24, 48, and 72 h. Transwell chambers were employed to test the migratory ability of VSMCs when incubated with homocysteine for 48 h. Different concentrations of rosuvastatin （10^-9-10^-5 mol/L） were added when VSMCs were induced with 1 000 pmol/L homocysteine. The expressions and activities of MMP-2 and TIMP-2 were examined after incubating for 24, 48, and 72 h, and the migration of VSMCs was also examined after incubating for 48 h. Results： Homocysteine （50-1000 μmol/L） increased the production and activation of MMP-2 and expression of TIMP-2 in a dose-dependent manner. However, when incubated with 5000 pmol/L homocysteine, the expression of MMP-2 was up-regulated, but its activity was down-regulated. Increased homocysteine-induced production and ac- tivation of MMP-2 were reduced by rosuvastatin in a dose-dependent manner whereas secretion of TIMP-2 was not significantly altered by rosuvastatin. Homocysteine （50-5000 μmol/L） stimulated the migration of VSMCs in a dose-dependent manner, but this effect was eliminated by rosuvastatin. Conclusions： Homocysteine （50-1000 μmol/L） significantly increased the production and activation of MMP-2, the expression of TIMP-2, and the migration of VSMCs in a dose-dependent manner. Additional extracellular rosuvastatin can decrease the excessive expression an展开更多
Objective： The present study was designed to use an in vivo rabbit ear scar model to investigate the efficacy of systemic administration of endostatin in inhibiting scar formation. Methods： Eight male New Zealand wh...Objective： The present study was designed to use an in vivo rabbit ear scar model to investigate the efficacy of systemic administration of endostatin in inhibiting scar formation. Methods： Eight male New Zealand white rabbits were randomly assigned to two groups. Scar model was established by making six full skin defect wounds in each ear. For the intervention group, intraperitoneal injection of endostatin was performed each day after the wound healed （about 15 d post wounding）. For the control group, equal volume of saline was injected. Thickness of scars in each group was measured by sliding caliper and the scar microcirculatory perfusion was assessed by laser Doppler flowmetry on Days 15, 21, 28, and 35 post wounding. Rabbits were euthanatized and their scars were harvested for histological and proteomic analyses on Day 35 post wounding. Results： Macroscopically, scars of the control group were thicker than those of the intervention group. Significant differences between the two groups were observed on Days 21 and 35 （p〈0.05）. Scar thickness, measured by scar elevation index （SEI） at Day 35 post wounding, was significantly reduced in the intervention group （1.09±0.19） compared with the controls （1.36±0.28）. Microvessel density （MVD） observed in the intervention group （1.73±0.94） was significantly lower than that of the control group （5.63±1.78） on Day 35. The distribution of collagen fibers in scars treated with endostatin was relatively regular, while collagen fibers in untreated controls were thicker and showed disordered alignment. Western blot analysis showed that the expressions of type I collagen and Bcl-2 were depressed by injection of endostatin. Conclusions： Our results from the rabbit ear hypertrophic scar model indicate that systemic application of endostatin could inhibit local hypertrophic scar formation, possibly through reducing scar vascularization and angiogenesis. Our results indicated that endostatin may promote the apoptosis of endothelial cell展开更多
BACKGROUND: Marked hemodynamic alteration, commonly referred to as postreperfusion syndrome (PRS), often occurs after revascularization of the donor organ during orthotopic liver transplantation (OLT) and is associate...BACKGROUND: Marked hemodynamic alteration, commonly referred to as postreperfusion syndrome (PRS), often occurs after revascularization of the donor organ during orthotopic liver transplantation (OLT) and is associated with poor outcomes. This study aimed to investigate the incidence, predictive factors and clinical outcomes of PRS in Chinese patients following OLT at a liver transplantation center in China. METHODS: Over a 5-year period, 330 consecutive patients who had undergone OLT for hepatocellular carcinoma or cirrhosis were included in this retrospective study. PRS was defined as a >30% decrease in the mean arterial pressure compared with that before revascularization for more than 1 minute during the first 5 minutes of graft reperfusion. The patients were divided into 2 groups according to the development of PRS: group 1 (patients with PRS, n=56) and group 2 (patients without PRS, n=274). The demographic characteristics, operative and postoperative courses, and outcomes of the patients were analyzed using SPSS version 18.0. RESULTS: Multivariate regression analysis showed that left ventricular diastolic dysfunction determined by echocardiography and prolonged cold ischemia time were the independent risk factors for PRS. More patients in group 1 showed postoperative renal dysfunction than those in group 2 (19.23% vs 8.4%). Moreover, patients in group 1 also had higher intraoperative (7.14% vs 0%) and postoperative mortalities (26.92% vs 12.04%).CONCLUSION: Left ventricular diastolic dysfunction and prolonged cold ischemia time contribute to a high incidence of PRS, which is associated with adverse outcomes in Chinese patients following OLT.展开更多
氮素穗肥用量和结实期遮光可通过影响叶片光合和植株氮营养状况对水稻籽粒碳氮代谢能力产生调节作用,从而形成不同特征的稻米品质。为探明氮素穗肥用量与结实期遮光复合作用对常规粳稻品质的影响,于2019—2020年以生育期相近的常规粳稻...氮素穗肥用量和结实期遮光可通过影响叶片光合和植株氮营养状况对水稻籽粒碳氮代谢能力产生调节作用,从而形成不同特征的稻米品质。为探明氮素穗肥用量与结实期遮光复合作用对常规粳稻品质的影响,于2019—2020年以生育期相近的常规粳稻淮稻5号、南粳9108和扬农香28为材料,设置40.5 kg hm^(-2)(N1)、81.0 kg hm^(-2)(N2)、121.5 kg hm^(-2)(N3)3个氮素穗肥用量处理,并于抽穗至成熟期采用人工遮阴方式控制水稻冠层光照,包括100%自然光照(S0)和50%自然光照(S50)处理,研究了结实期不同光氮处理组合对稻米品质的影响效应。结果表明:糙米率、精米率、整精米率在S0条件下随氮素穗肥用量的增加呈先升后降趋势,在S50条件下呈下降趋势,其中S0N2处理的整精米率最高,加工品质较好;垩白粒率和垩白度均呈S50N3>S50N2>S50N1>S0N3>S0N2>S0N1的趋势,且穗肥氮素用量的增加和结实期遮光对稻米提高垩白粒率和垩白度具有累加作用。穗肥氮素用量增加和结实期遮光均降低直链淀粉含量和胶稠度,提高蛋白质含量,其中谷蛋白的变异系数高于其他蛋白组分。穗肥氮素用量增加和结实期遮光不利于稻米食味值评分,不同品种的食味特征值对食味值评分的直接影响有差异。水稻淀粉的峰值黏度、崩解值随穗肥氮素用量增加和结实期光照强度下降而降低,消减值则上升,光氮复合作用增加了上述指标的差异。在穗肥氮素用量与结实期遮光复合作用下从直链淀粉含量和蛋白质含量比值趋势性变化来分析,结实期植株碳氮代谢能力强弱发生了变化。直链淀粉含量和蛋白质含量均与稻米食味值评分呈极显著的负相关关系,其中蛋白质的相关系数更大。因此,适量减施氮素穗肥有利于水稻结实期遭遇寡照后的稻米加工品质、外观品质及蒸煮食味品质提升,并且降低直链淀粉含量特别是蛋白质含量可能是展开更多
目的:研究不同分子量猪皮胶原肽的抗氧化特性,筛选出抗氧化活性较强的组分。方法:采用仿生酶解技术酶解新鲜猪皮得到酶解原液,酶解原液经超滤得到M<1 k Da、1 k Da<M<3 k Da、M>3 k Da 3个不同分子量肽段,猪皮经水提取得到...目的:研究不同分子量猪皮胶原肽的抗氧化特性,筛选出抗氧化活性较强的组分。方法:采用仿生酶解技术酶解新鲜猪皮得到酶解原液,酶解原液经超滤得到M<1 k Da、1 k Da<M<3 k Da、M>3 k Da 3个不同分子量肽段,猪皮经水提取得到猪皮水提液,上述5组分分别冻干,得到冻干粉。对不同分子量范围的猪皮胶原肽5组分进行肽含量测定和抗氧化性研究,包括对DPPH·自由基、O2-·自由基及·OH自由基的清除实验。结果:各组分的肽含量分别为酶解原液组分64.62%、1~3 k Da组分62.63%、大于3 k Da组分62.13%、水提液组分60.57%、小于1 k Da组分59.75%。各组分清除DPPH·自由基能力顺序为:小于1 k Da组分>1~3k Da组分>酶解原液组分>水提液组分>大于3 k Da组分;各组分清除O2-·自由基能力顺序为:小于1 k Da组分>酶解原液组分>1~3 k Da组分>大于3 k Da组分>水提液组分;各组分清除·OH自由基能力顺序为:小于1 k Da组分>1~3 k Da组分>酶解原液组分>大于3 k Da组分>水提液组分。结论:不同分子量的猪皮胶原肽组分均有一定的抗氧化活性,其中M<1 k Da组分具有较强的自由基清除能力。展开更多
We operated a p-type point contact high purity germanium(PPCGe)detector(CDEX-1B,1.008 kg)in the China Jinping Underground Laboratory(CJPL)for 500.3 days to search for neutrinoless double beta(0νββ)decay of ^(76)Ge....We operated a p-type point contact high purity germanium(PPCGe)detector(CDEX-1B,1.008 kg)in the China Jinping Underground Laboratory(CJPL)for 500.3 days to search for neutrinoless double beta(0νββ)decay of ^(76)Ge.A total of 504.3 kg⋅day effective exposure data was accumulated.The anti-coincidence and the multi/single-site event(MSE/SSE)discrimination methods were used to suppress the background in the energy region of interest(ROI,1989–2089 keV for this work)with a factor of 23.A background level of 0.33 counts/(keV⋅kg⋅yr)was realized.The lower limit on the half life of^(76)Ge 0νββdecay was constrained as T_(1/2)^(0ν)>1.0×10^(23)yr(90%C.L.),corresponding to the upper limits on the effective Majorana neutrino mass:<mββ><3.2–7.5 eV.展开更多
基金The author thanks the National Natural Science Foundation of China （No. 81470266）.
文摘Background：Pyroptosis is the term for caspase-l-dependent cell death associated with pro-inflammatory cytokines.The role of alveolar macrophage （AM） pyroptosis in the pathogenesis of the acute lung injury and acute respiratory distress syndrome （ALI/ARDS） remains unclear.Methods：C57BL/6 wild-type mice were assigned to sham,lipopolysaccharide （LPS） ＋ vehicle,LPS ＋ acetyl-tyrosyl-valyl-alanyl-aspartyl-chloromethylketone （Ac-YVAD-CMK） and LPS ＋ Z-Asp-Glu-Val-Asp-fluoromethylketone groups.Mice were given intraperitoneal （IP） injections of LPS.Drugs were IP injected 1 h before LPS administration.Mice were sacrificed 16 h after LPS administration,and AMs were isolated.Western blot analysis for active caspase-1 and cleaved caspase-3,evaluation of lung injury and a cytokine release analysis were performed.AMs were treated with LPS and adenosine triphosphate （ATP）;caspase-l-dependent cell death was evaluated using flow cytometry;the apoptosis-associated speck-like protein containing a caspase recruitment domain （ASC） pyroptosomes were examined by immunofluorescence.Results：The expression of activated caspase-1 in AMs was enhanced following LPS challenge compared with the sham group.In the ex vivo study,the caspase-1/propidium iodide-positive cells,caspase-1 specks and ASC pyroptosomes were up-regulated in AMs following LPS/ATP stimulation.The specific caspase-1 inhibitor Ac-YVAD-CMK inhibited the activation of caspase-1 and pyroptotic cell death.Ac-YVAD-CMK also reduced the lung injury,pulmonary edema and total protein in bronchoalveolar lavage fluid （BALF）.In addition,Ac-YVAD-CMK significantly inhibited interleukin-β （IL-lβ） release both in serum and BALF and reduced the levels of IL-18,tumor necrosis factor-α （TNF-α）,High Mobility Group Box 1 （HMGB1） in BALF during LPS-induced ALI/ARDS.Conclusions：This study reported AM pyroptosis during LPS-induced ALI/ARDS in mice and has demonstrated that Ac-YVAD-CMK can prevent AM-induced pyroptosis and lung injury.These
基金Project supported by the Health Ministry Scientific Research Fund of China (No. WKJ2011-2-018)the Zhejiang Provincial Natural Science Foundation of China (No. Y2100535)+3 种基金the Key Social Development Project of Zhejiang Province (No. 2010A23010)the Science and Technology Projects of Shaoxing (No. 2011A23011)the Science and Technology Plan Project of Zhejiang Province (No. 2012C33040)the Zhejiang Provincial Program for the Cultivation of High-Level Innovative Health Talents, China
文摘Objective： To test the influence of homocysteine on the production and activation of matrix metalloproteinase-2 （MMP-2） and tissue inhibitors of matrix metalloproteinase-2 （TIMP-2） and on cell migration of cultured rat vascular smooth muscle cells （VSMCs）. Also, to explore whether rosuvastatin can alter the abnormal secretion and activation of MMP-2 and TIMP-2 and migration of VSMCs induced by homocysteine. Methods： Rat VSMCs were incubated with different concentrations of homocysteine （50-5000 μmol/L）. Western blotting and gelatin zymography were used to investigate the expressions and activities of MMP-2 and TIMP-2 in VSMCs in culture medium when induced with homocysteine for 24, 48, and 72 h. Transwell chambers were employed to test the migratory ability of VSMCs when incubated with homocysteine for 48 h. Different concentrations of rosuvastatin （10^-9-10^-5 mol/L） were added when VSMCs were induced with 1 000 pmol/L homocysteine. The expressions and activities of MMP-2 and TIMP-2 were examined after incubating for 24, 48, and 72 h, and the migration of VSMCs was also examined after incubating for 48 h. Results： Homocysteine （50-1000 μmol/L） increased the production and activation of MMP-2 and expression of TIMP-2 in a dose-dependent manner. However, when incubated with 5000 pmol/L homocysteine, the expression of MMP-2 was up-regulated, but its activity was down-regulated. Increased homocysteine-induced production and ac- tivation of MMP-2 were reduced by rosuvastatin in a dose-dependent manner whereas secretion of TIMP-2 was not significantly altered by rosuvastatin. Homocysteine （50-5000 μmol/L） stimulated the migration of VSMCs in a dose-dependent manner, but this effect was eliminated by rosuvastatin. Conclusions： Homocysteine （50-1000 μmol/L） significantly increased the production and activation of MMP-2, the expression of TIMP-2, and the migration of VSMCs in a dose-dependent manner. Additional extracellular rosuvastatin can decrease the excessive expression an
基金supported by the National Natural Science Foundation of China (No.81272120)the Health Department of the Zhejiang Province (No.2007B086),China
文摘Objective： The present study was designed to use an in vivo rabbit ear scar model to investigate the efficacy of systemic administration of endostatin in inhibiting scar formation. Methods： Eight male New Zealand white rabbits were randomly assigned to two groups. Scar model was established by making six full skin defect wounds in each ear. For the intervention group, intraperitoneal injection of endostatin was performed each day after the wound healed （about 15 d post wounding）. For the control group, equal volume of saline was injected. Thickness of scars in each group was measured by sliding caliper and the scar microcirculatory perfusion was assessed by laser Doppler flowmetry on Days 15, 21, 28, and 35 post wounding. Rabbits were euthanatized and their scars were harvested for histological and proteomic analyses on Day 35 post wounding. Results： Macroscopically, scars of the control group were thicker than those of the intervention group. Significant differences between the two groups were observed on Days 21 and 35 （p〈0.05）. Scar thickness, measured by scar elevation index （SEI） at Day 35 post wounding, was significantly reduced in the intervention group （1.09±0.19） compared with the controls （1.36±0.28）. Microvessel density （MVD） observed in the intervention group （1.73±0.94） was significantly lower than that of the control group （5.63±1.78） on Day 35. The distribution of collagen fibers in scars treated with endostatin was relatively regular, while collagen fibers in untreated controls were thicker and showed disordered alignment. Western blot analysis showed that the expressions of type I collagen and Bcl-2 were depressed by injection of endostatin. Conclusions： Our results from the rabbit ear hypertrophic scar model indicate that systemic application of endostatin could inhibit local hypertrophic scar formation, possibly through reducing scar vascularization and angiogenesis. Our results indicated that endostatin may promote the apoptosis of endothelial cell
基金supported by a grant from the Key Programs of STCSM (No. 10411951300)
文摘BACKGROUND: Marked hemodynamic alteration, commonly referred to as postreperfusion syndrome (PRS), often occurs after revascularization of the donor organ during orthotopic liver transplantation (OLT) and is associated with poor outcomes. This study aimed to investigate the incidence, predictive factors and clinical outcomes of PRS in Chinese patients following OLT at a liver transplantation center in China. METHODS: Over a 5-year period, 330 consecutive patients who had undergone OLT for hepatocellular carcinoma or cirrhosis were included in this retrospective study. PRS was defined as a >30% decrease in the mean arterial pressure compared with that before revascularization for more than 1 minute during the first 5 minutes of graft reperfusion. The patients were divided into 2 groups according to the development of PRS: group 1 (patients with PRS, n=56) and group 2 (patients without PRS, n=274). The demographic characteristics, operative and postoperative courses, and outcomes of the patients were analyzed using SPSS version 18.0. RESULTS: Multivariate regression analysis showed that left ventricular diastolic dysfunction determined by echocardiography and prolonged cold ischemia time were the independent risk factors for PRS. More patients in group 1 showed postoperative renal dysfunction than those in group 2 (19.23% vs 8.4%). Moreover, patients in group 1 also had higher intraoperative (7.14% vs 0%) and postoperative mortalities (26.92% vs 12.04%).CONCLUSION: Left ventricular diastolic dysfunction and prolonged cold ischemia time contribute to a high incidence of PRS, which is associated with adverse outcomes in Chinese patients following OLT.
文摘氮素穗肥用量和结实期遮光可通过影响叶片光合和植株氮营养状况对水稻籽粒碳氮代谢能力产生调节作用,从而形成不同特征的稻米品质。为探明氮素穗肥用量与结实期遮光复合作用对常规粳稻品质的影响,于2019—2020年以生育期相近的常规粳稻淮稻5号、南粳9108和扬农香28为材料,设置40.5 kg hm^(-2)(N1)、81.0 kg hm^(-2)(N2)、121.5 kg hm^(-2)(N3)3个氮素穗肥用量处理,并于抽穗至成熟期采用人工遮阴方式控制水稻冠层光照,包括100%自然光照(S0)和50%自然光照(S50)处理,研究了结实期不同光氮处理组合对稻米品质的影响效应。结果表明:糙米率、精米率、整精米率在S0条件下随氮素穗肥用量的增加呈先升后降趋势,在S50条件下呈下降趋势,其中S0N2处理的整精米率最高,加工品质较好;垩白粒率和垩白度均呈S50N3>S50N2>S50N1>S0N3>S0N2>S0N1的趋势,且穗肥氮素用量的增加和结实期遮光对稻米提高垩白粒率和垩白度具有累加作用。穗肥氮素用量增加和结实期遮光均降低直链淀粉含量和胶稠度,提高蛋白质含量,其中谷蛋白的变异系数高于其他蛋白组分。穗肥氮素用量增加和结实期遮光不利于稻米食味值评分,不同品种的食味特征值对食味值评分的直接影响有差异。水稻淀粉的峰值黏度、崩解值随穗肥氮素用量增加和结实期光照强度下降而降低,消减值则上升,光氮复合作用增加了上述指标的差异。在穗肥氮素用量与结实期遮光复合作用下从直链淀粉含量和蛋白质含量比值趋势性变化来分析,结实期植株碳氮代谢能力强弱发生了变化。直链淀粉含量和蛋白质含量均与稻米食味值评分呈极显著的负相关关系,其中蛋白质的相关系数更大。因此,适量减施氮素穗肥有利于水稻结实期遭遇寡照后的稻米加工品质、外观品质及蒸煮食味品质提升,并且降低直链淀粉含量特别是蛋白质含量可能是
文摘目的:研究不同分子量猪皮胶原肽的抗氧化特性,筛选出抗氧化活性较强的组分。方法:采用仿生酶解技术酶解新鲜猪皮得到酶解原液,酶解原液经超滤得到M<1 k Da、1 k Da<M<3 k Da、M>3 k Da 3个不同分子量肽段,猪皮经水提取得到猪皮水提液,上述5组分分别冻干,得到冻干粉。对不同分子量范围的猪皮胶原肽5组分进行肽含量测定和抗氧化性研究,包括对DPPH·自由基、O2-·自由基及·OH自由基的清除实验。结果:各组分的肽含量分别为酶解原液组分64.62%、1~3 k Da组分62.63%、大于3 k Da组分62.13%、水提液组分60.57%、小于1 k Da组分59.75%。各组分清除DPPH·自由基能力顺序为:小于1 k Da组分>1~3k Da组分>酶解原液组分>水提液组分>大于3 k Da组分;各组分清除O2-·自由基能力顺序为:小于1 k Da组分>酶解原液组分>1~3 k Da组分>大于3 k Da组分>水提液组分;各组分清除·OH自由基能力顺序为:小于1 k Da组分>1~3 k Da组分>酶解原液组分>大于3 k Da组分>水提液组分。结论:不同分子量的猪皮胶原肽组分均有一定的抗氧化活性,其中M<1 k Da组分具有较强的自由基清除能力。
基金Supported by the National Key Research and Development Program of China(2017YFA0402201,2022YFA1604701,2022YFA1605000)the National Natural Science Foundation of China(12322511,12175112,12005111,11725522)。
文摘We operated a p-type point contact high purity germanium(PPCGe)detector(CDEX-1B,1.008 kg)in the China Jinping Underground Laboratory(CJPL)for 500.3 days to search for neutrinoless double beta(0νββ)decay of ^(76)Ge.A total of 504.3 kg⋅day effective exposure data was accumulated.The anti-coincidence and the multi/single-site event(MSE/SSE)discrimination methods were used to suppress the background in the energy region of interest(ROI,1989–2089 keV for this work)with a factor of 23.A background level of 0.33 counts/(keV⋅kg⋅yr)was realized.The lower limit on the half life of^(76)Ge 0νββdecay was constrained as T_(1/2)^(0ν)>1.0×10^(23)yr(90%C.L.),corresponding to the upper limits on the effective Majorana neutrino mass:<mββ><3.2–7.5 eV.
