广州、湛江、茂名、江门四市部份十七万人口中支气管哮喘流行病学情况的初步调查

目前,支气管哮喘(以下简称哮喘)在广东地区的流行病学情况尚无完整的数据。哮喘的患病率可因调查地区,人数,对象,方法和环境因素等不同而相差悬殊。我们于一九八三年四月至一九八四年七月对广州、湛江、茂名、江门四市的部份工厂,学校,街道居民点共172,162人进行了哮喘患病情况的初步调查

早期宫颈癌部分子宫照射的物理剂量学研究

目的探索宫颈癌根治性同期放化疗中部分子宫照射对减少盆腔正常脏器剂量的意义。方法选取2014年10月至2016年10月在汕头大学医学院附属肿瘤医院接受根治性放化疗的20例宫颈癌患者,为每个患者设计2套放疗计划:(1)全子宫照射:临床靶区(CTV)包括完整子宫;(2)部分子宫照射:CTV包括肿瘤靶区(GTV)以外10mm的子宫组织。比较每个患者2组放疗计划的参数和盆腔正常器官受照射剂量。结果部分子宫照射和全子宫照射适形度和均匀度差异无统计学意义;部分子宫照射的计划靶区(PTV)体积为(1 065±134)cm~3,小于全子宫照射的PTV体积(1 141±133)cm~3(P=0.00);部分子宫照射能减少部分盆腔脏器受照剂量:部分子宫照射膀胱V45=(27±9)%,全子宫照射V45=(32±11)%(P=0.01);部分子宫照射直肠V40=(84±9)%,全子宫照射直肠V40=(86±9)%(P=0.01);部分子宫照射小肠V45=(76±53)cm~3,全子宫照射小肠V45=(79±56)cm~3(P=0.03)。结论部分子宫照射能减少PTV体积,并减少部分盆腔正常器官受照射剂量,但所减少的绝对体积较小,临床意义不大。广东省科技厅科技计划项目(2016A020215188);;汕头市医疗科技计划项目(汕府科[2015]123号

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

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 → 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