Preparation,identification and application of monoclonal antibody against urease subuint B of Helicobacter pylori

目的制备抗幽门螺杆菌(HP)的单克隆抗体(MAb),并对该HP MAb进行分析鉴定,建立一种检测患者由于HP感染而在血清中产生HP抗体的竞争ElISA检测方法。方法用灭活的HP免疫bAlb/C小鼠,通过杂交瘤技术制备HP MAb。我们采用HP混合蛋白包括毒素相关蛋白A(CAgA)、空泡毒素A(VACA)和尿素酶以及灭活的HP菌体筛选阳性杂交瘤细胞株,用ElISA和WESTErn blOT等技术对所获得的HP MAb进行鉴定。利用辣根过氧化物酶(HrP)标记所筛选的HP MAb来建立一个可检测患者血清中HP抗体的竞争ElISA。结果通过大规模的杂交瘤筛选,我们选择了1株将其命名为C3 HP MAb,其抗体亚型为Igg2A,腹水效价可达1x107。WESTErn blOT法、ElISA和质谱检测结果显示,该C3 HP MAb能特异地识别HP的尿素酶b亚单位。用这个C3 HP MAb,我们建立了一种可检测患者血清中HP抗体的竞争ElISA。结论成功获得一种可以特异识别HP尿素酶b亚单位的MAb,建立了一种可检测患者血清中HP抗体的竞争ElISA。Objective To prepare and characterize the monoclonal antibody(mAb) against Helicobacter pylori(Hp)and establish a competitive ELISA used for detection of Hp antibodies in the sera of Hp-infected patients.Methods BALB /c mice were immunized with inactivated Hp to generate Hp mAb using the hybridoma technology.Hp mixed proteins including cytotoxin-associated gene A(CagA),vacuolating cytotoxin A(VacA) and urease,as well as inactivated Hp were applied to screen positive hybridoma.Selected Hp mAb was analyzed and characterized with ELISA and Western blotting,and then labeled with horseradish peroxidase( HRP) for establishing a competitive ELISA to detect Hp antibodies in the sera of Hp-infected patients.Results One Hp mAb named as C3 was selected after screening large amount of hybridoma,and the C3 Hp mAb was special for IgG2 a subtype with the affinity titer of 1 × 107.Western blotting,ELISA and mass spectrum analysis indicated that the C3 Hp mAb could recognize Hp urease subunit B specifically.Using the C3 Hp mAb,we developed a competitive ELISA which could be used to detect Hp antibodies in the sera of Hp-infected patients.Conclusion We successfully obtained one mAb that could specifically recognize Hp urease subunit B and developed a competitive ELISA using the Hp mAb.福建省科技重点项目(2011Y0050); 厦门市科技计划项目(3502Z20123009); 国家基础科学人才培养基金(J1310027

2000–2010年中国典型陆地生态系统实际蒸散量和水分利用效率数据集

蒸散是陆地生态系统水分循环和能量平衡的关键过程,水分利用效率是反映生态系统碳水循环间耦合关系的重要指标,二者在生态学、农学、水文学、气候学等多个学科中均具有重要的应用价值。涡度相关法被认为是现今唯一能直接测量生物圈与大气间物质与能量交换通量的标准方法,已成为生态系统尺度碳水交换通量观测的主要方法。本文通过整合中国陆地生态系统通量观测联盟(China FLUX)的长期观测数据和中国区域其他观测站点基于涡度相关法发表的文献数据,构建了一套中国典型陆地生态系统实际蒸散量和水分利用效率数据集。本数据集共有实际蒸散量数据记录143条、水分利用效率数据记录96条,涉及5种生态系统类型45个生态系统,时间跨度为2000–2010年。本数据集可以为陆地生态系统碳水循环、生态系统管理和评估、全球变化等相关领域的研究提供数据支持

艾比湖周边灌丛沙堆风沙沉积记录的气候环境演化/Record for Climate Revolution in Aeolian Deposit of Nabkhas around the Ebinur Lake[J]

选择位于西风区的新疆艾比湖周边灌丛沙堆为研究对象,利用光释光测年初步建立风沙沉积的时间序列,分析了风沙沉积粒度和地球化学元素两个环境代用指标的古气候意义,并通过区域对比和综合分析,初步建立区域风沙气候环境演变序列.结果表明:研究区灌丛沙堆主要发育于晚全新世,缺失早中全新世的风沙沉积.晚冰期以来,艾比湖地区的风沙气候环境演变经历了一系列冷湿(凉湿)— 暖干(温干)的变化过程,其中暖干(温干)时期气候干旱,风力强劲,湖滨阶地主要发生风蚀过程,不利于灌丛沙堆的发育.晚全新世以来,艾比湖周边灌丛沙堆发育较普遍,风沙沉积至少记录了3次相对干旱期和3次相对湿润期.灌丛沙堆记录的风沙气候环境演化序列与北疆其他全新世沉积记录有较好的一致性,基本遵循晚次冰期以来气候变化的西风模式,同时也受到局地风沙地貌环境的影响

Prediction of Energy Resolution in the JUNO Experiment

International audienceThis paper presents the energy resolution study in the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The study reveals an energy resolution of 2.95% at 1 MeV. Furthermore, the study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data taking. Moreover, it provides a guideline in comprehending the energy resolution characteristics of liquid scintillator-based detectors

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel