大连蛇岛蝮蛇类凝血酶基因克隆与表达研究

根据同源性设计引物，通过RT－PCR方法从大连蛇岛蝮蛇毒腺总RNA中合成扩增出类凝血酶基因，并由此推测出其相应的氨基酸序列。将该基因克隆到表达载体pPIC9K中，经电激转化后整合至毕氏酵母细胞中获得表达。该表达产物经两步柱层析后，进行聚丙烯酰胺凝胶电泳，获得单一条带，并表现较强的生色底物活性

大连蛇岛蝮蛇类凝血酶基因克隆与表达研究

根据同源性设计引物,通过RT-PCR方法从大连蛇岛蝮蛇毒腺总RNA中合成扩增出类凝血酶基因,并由此推测出其相应的氨基酸序列.将该基因克隆到表达载体pPIC9K中,经电激转化后整合至毕氏酵母细胞中获得表达.该表达产物经两步柱层析后,进行聚丙烯酰胺凝胶电泳,获得单一条带,并表现较强的生色底物活性

广西巴马地区长寿老人ApoE基因多态性与认知功能的关系

目的：研究广西巴马地区长寿老人载脂蛋白E(ApoE)基因多态性的分布及其与认知功能改变的关系。方法：采用简易精神状态量表(MMSE)对112例90岁以上广西巴马地区长寿老人进行认知功能检查．并用限制性酶切片段长度多态性分析(PCR—RFLP)方法进行ApoE基因分型。根据MMSE得分将研究对象分为认知功能正常组和认知功能障碍组．比较两组人群的基因型、基因频率的分布特征。结果：巴马长寿老人中发生认知功能障碍者占14．29％。长寿老人中ApoEε3／3基因型分布的百分比最大．其次是ε2／3。而ε4／4最少。ApoE各基因型和等位基因频率认知功能正常组和认知功能障碍组相比较．84等位基因频率认知障碍组明显高于认知正常组（P<0．01)，ε4基因携带者认知功能障碍发生率明显高于其他基因携带者。结论：巴马地区长寿人群中，ApoEε3／3为最常见的基因型。而ε4／4最少；ApoE基因多态性与巴马长寿老人认知功能改变有关联：ApoEε4基因仍然是长寿老人认知功能障碍发病的危险因子．较低的ApoEε4等位基因频率可能是巴马地区长寿老人认知功能保存较好的原因之一

广西巴马地区长寿老人 ApoE 基因多态性与认知功能的关系

目的:研究广西巴马地区长寿老人载脂蛋白E（ApoE）基因多态性的分布及其与认知功能改变的关系。方法:采用简易精神状态量表（MMSE）对112例90岁以上广西巴马地区长寿老人进行认知功能检查,并用限制性酶切片段长度多态性分析（PCR-RFLP）方法进行ApoE 基因分型。根据MMSE 得分将研究对象分为认知功能正常组和认知功能障碍组.比较两组人群的基因型、基因频率的分布特征。结果:巴马长寿老人中发生认知功能障碍者占14.29%。长寿老人中ApoEε3/3基因型分布的百分比最大,其次是ε2/3,而ε4/4最少。ApoE 各基因型和等位基因频率认知功能正常组和认知功能障碍组相比较,ε4等位基因频率认知障碍组明显高于认知正常组（P<0.01）,ε4基因携带者认知功能障碍发生率明显高于其他基因携带者。结论:巴马地区长寿人群中,ApoEε3/ 3为最常见的基因型,而ε4/4最少;ApoE 基因多态性与巴马长寿老人认知功能改变有关联;ApoEε4基因仍然是长寿老人认知功能障碍发病的危险因子,较低的ApoEε4等位基因频率可能是巴马地区长寿老人认知功能保存较好的原因之一

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

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ 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 suppression of 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% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies