学龄儿童眼球后极部脉络膜厚度及相关因素分析

【目的】探讨岭南地区学龄儿童黄斑中心凹及周围3mm范围内脉络膜厚度的变化以及相关影响因素。【方法】招募2017年1月1日至2018年6月1日就诊于海南省眼科医院的健康学龄儿童195人，测量眼轴（AXL）、黄斑中心凹下脉络膜厚度（SFCT）以及黄斑中心凹上方、下方、鼻侧、颞侧1mm及3mm脉络膜厚度。根据等效球镜度（SE）分为远视组、正视组及低中高度近视组，比较各组黄斑区不同位点脉络膜厚度分布。跟踪观察香港特区新界东华三院马锦灿纪念小学二年级同学45人，根据儿童屈光状态分为近视组（基础SE<-0.25D或者1年后SE<-0.25D）和正视远视组（基础SE和1年后SE均≥-0.25D），比较1年前后黄斑区不同位点脉络膜厚度变化，并研究其变化与SE、眼轴改变的相关性。【结果】7~16岁学龄儿童脉络膜厚度在黄斑中心凹下为（SF）250（204~314）μm，以黄斑中心凹为中心向鼻侧和下方变薄，向颞侧和上方变厚，最薄点位于鼻侧3mm处，最厚位于颞侧1mm处，随近视度数增加，黄斑区各测量点脉络膜厚度均有不同程度变薄，且黄斑中心凹及周围1mm处脉络膜变薄较周边更加显著（成组秩和检验，P<0.05）。45名香港小学生随访1年后观察结果显示被检儿童各测量点脉络膜厚度与一年前比较均有不同程度的减少（配对t检验，P<0.05）。近视组与正视远视组比较AXL增长、SE减少明显，SFCT和周围各点脉络膜厚度减少均大于正视远视组，差异有统计学意义（成组秩和检验，P<0.05）。【结论】学龄儿童的后极部黄斑区的脉络膜厚度呈现不均匀分布，黄斑中心凹下脉络膜厚度较周边脉络膜厚度对近视的发展更为敏感

基于<italic>COI</italic>基因的浙江省内黄缘闭壳龟遗传多样性研究

为了解浙江省内不同黄缘闭壳龟（Cuora flavomarginata）群体的种质资源现状，基于线粒体DNA COI序列对来自浙江省内野外和养殖场的8个黄缘闭壳龟群体的遗传多样性和遗传结构进行比较分析。结果表明：黄缘闭壳龟线粒体COI基因序列长度为1 040 bp，A=27.4%、T=30.5%、C=24.6%、G=17.5%，有较强的AT偏好性；共定义9个单倍型，单倍型多样性（Hd）为（0.799 00±0.210 00），核苷酸多样性（Pi）为 （0.002 09±0.001 47），呈“高Hd低Pi”遗传分布；不同黄缘闭壳龟群体间的遗传距离为0~0.003，群体内部的遗传距离为0~0.004，其中磐安后阁村（YS）群体内部的遗传距离最大，为0.004；单倍型系统发育树并未呈现明显的谱系结构；群体间遗传分化指数（FST）为-0.347 52~0.822 22，8个群体的遗传分化不显著（p&gt;0.05）；中性检验（Tajima’s D=-0.366 27，Fu’s FS=-0.605）与核苷酸错配分布均表明，浙江省内黄缘闭壳龟群体并未经历种群扩张事件，同时，由Mantel检验可知，遗传距离与地理距离没有显著的相关性（R=0.293 8，p&gt;0.05）；AMOVA分子方差结果显示，群体内的遗传变异高于群体间（85.06%&gt;14.94%）。研究表明，浙江省内黄缘闭壳龟群体之间为高单倍型多样性和低核苷酸多样性的遗传特征，并且存在一定水平的遗传分化，群体内存在明显的基因交流，根据COI基因分析显示，在磐安县获得的野生黄缘闭壳龟个体确定为黄缘闭壳龟浙江种，同时也发现存在浙江种与安徽种的杂交种，建议将分化程度不同的黄缘闭壳龟群体划分为不同单元保护。研究结果为浙江省内黄缘闭壳龟种质资源开发利用和合理制定保护措施提供了基础依据

135MeV／u~（12）C和铁相互作用中靶余核的质量分布

用核化学技术测定了１３５ＭｅＶ／ｕ１２Ｃ和铁相互作用中的靶余核的生成截面，通过高斯电荷分布函数得到了靶余核的质量分布．与４６ＭｅＶ／ｕ１２Ｃ＋Ｃｕ相比，发现Ａ＜３０质量区的产额明显增加，且产物有偏向丰中子一侧的趋势．实验测定的质量分布与熔合碎裂模型和级联两体模型的计算结果进行了比较，结果似乎表明在很高入射能情况下多重碎裂衰变是Ａ＜３０靶余核生成的主要反应机制．The formation cross sections of target residues have been measured from the interaction of iron with 135MeV/u12C ions.With the help of assumption of Gaussian charge distribution,the mass yield distribution was obtained.We found that the yield in mass region of A<30 were notably increased and the products got away to neutron-excessive.The experimental results were compared with calculations based on the statistical fusion fragmentation model and on the sequential binary decay model,respectively. It seems国家自然科学基

聚集诱导发光

聚集诱导发光(AIE)是唐本忠院士于2001年提出的一个科学概念,是指一类在溶液中不发光或者发光微弱的分子聚集后发光显著增强的现象。高效固态发光的AIE材料有望从根本上解决有机发光材料面临的聚集导致发光猝灭难题,具有重大的实际应用价值。从分子内旋转受限到分子内运动受限,从聚集诱导发光到聚集体科学,AIE领域已经取得了许多原创性的成果。在本综述中,我们从AIE材料的分类、机理、概念衍生、性能、应用和挑战等方面讨论了AIE领域最近取得的显著进展。希望本综述能激发更多关于分子聚集体的研究,并推动材料、化学和生物医学等学科的进一步交叉融合和更大发展。 Aggregation-induced emission (AIE), conceptually coined by Prof. Ben Zhong Tang in 2001, refers to a unique photophysical phenomenon non- or weakly emissive luminogens in dilute solutions emit intensely upon aggregation. AIE can solve the aggregation-caused quenching problem that traditional fluorophores are suffering from and hold great technological values for practical applications. The past 20 years have witnessed the rapid development of AIE research, from the restriction of intramolecular rotations to restriction of intramolecular motions, and from AIE to aggregate science, and many original results have been achieved. In this review, we summarize the advances in the field of AIE and its related areas. We specifically discuss the recent progress in AIE area, including material classification, mechanism, concept derivation, property, applications, and challenges. It is hoped that this review will inspire more research into the molecular aggregate level and make significant advances in materials, chemistry and biological sciences

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^

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