PT109改善链脲佐菌素诱导的散发性阿尔茨海默病小鼠认知功能障碍的作用及机制

目的观察PT109能否改善侧脑室注射链脲佐菌素（icv-STZ）诱导的散发性AD小鼠模型的认知功能障碍并对其机制进行初步探讨。方法32只7周龄雄性C57BL/6小鼠分为正常组（7只）、模型组（7只）、PT109低剂量组（9只）、PT109高剂量组（9只）。将STZ于第1和3天注射入小鼠侧脑室建立散发性阿尔茨海默病小鼠模型；（3mg/kg，每个注射位点5μL）造模后，分别腹腔注射PT109（30、100 mg·kg-1·d-1），2周后通过Morris水迷宫和避暗实验评价小鼠学习记忆能力；随后通过免疫荧光、免疫组化、免疫印迹、高尔基染色等方法检测小胶质细胞、神经元、树突棘、磷酸化Tau蛋白等AD相关指标。结果行为学实验结果显示：PT109可改善icv-STZ小鼠的学习记忆障碍；免疫荧光及组化结果显示：与模型组相比，PT109减少海马区域Iba1阳性细胞数量（低剂量：P <0.001， 高剂量：P <0.001），高剂量PT109增加海马和皮层区域MAP2和Tuj1阳性细胞总数量（P <0.05， P <0.01），差异具有统计学意义。高尔基染色结果显示：与模型组相比，PT109增加树突棘密度（低剂量：P <0.001， 高剂量：P <0.001），差异具有统计学意义。免疫印迹实验结果表明：与模型组相比，PT109降低NLRP3（高剂量：P <0.05）、磷酸化Tau蛋白的表达水平（低剂量：P <0.05， 高剂量：P <0.01），高剂量PT109提高PSD95（P <0.05）、磷酸化GSK3β（P <0.05）的表达水平，差异具有统计学差异。结论PT109可改善icv-STZ诱导的小鼠学习记忆障碍，可能与调节GSK3β/Tau相关通路有关

丙烯醛体内外诱导神经元铁死亡的初步研究

目的探究丙烯醛是否能够诱发体内外发生铁死亡现象。方法体外：给予小鼠海马神经元细胞系HT22细胞丙烯醛进行造模，采用铁死亡抑制剂铁抑素-1（Fer-1）与去铁胺（DFO）进行保护。MTT法检测细胞存活率；自由基探针二氢乙啶（DHE）与亚铁探针FerroOrange检测细胞内自由基与亚铁离子含量；透射电镜观察正常与模型组的线粒体超微形态与结构；Western blot法检测铁死亡相关蛋白表达的情况。体内：雄性C57BL/6小鼠，7~8周龄每日给予3 mg/kg的丙烯醛分别进行造模1、2、4周，并对海马区域进行Western blot法检测铁死亡相关蛋白表达的情况。结果丙烯醛显著降低HT22细胞的存活率，并诱导线粒体皱缩和嵴数目减少。同时丙烯醛可显著增加细胞内自由基与亚铁离子。此外，在细胞水平丙烯醛促进环氧化酶2（COX-2）、铁蛋白重链1（FTH1）表达上升，谷胱甘肽过氧化物酶4（GPX4）表达减少；在动物水平丙烯醛促进COX-2表达上升，GPX4、FTH1表达减少。结论丙烯醛可在体内外诱导神经元发生铁死亡现象，提示铁死亡抑制剂可以用来缓解与丙烯醛有关的中枢神经系统疾病，如阿尔兹海默病

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^

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

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