Discussion of screening strategy of retinopathy of prematurity

目的:根据早产儿出生体重和出生胎龄为指标,探讨早产儿视网膜病变的临床筛查标准和初次筛查时间。方法:收集2008年2月~2011年2月厦门市妇幼保健院nICu病区1 148例早产儿,使用双目间接眼底镜进行眼底检查,收集相关临床资料进行统计分析。结果:出生体重≤1 000 g、1 001~1 250 g、1 251~1 500 g、1 501~1 750 g、1 751~2 000 g、>2 000 g各组间阈值rOP发生率比较有统计学差异(χ2=201.54,P32周时阈值rOP发病率明显降低;rOC曲线显示在出生胎龄32.07周面积最大;出现阈值rOP时的矫正胎龄﹤35周的8例早产儿,出生后周龄均在4~6周。结论:出生体重≤1 500 g和出生胎龄≤32周是rOP筛查指标;初次筛查时间在矫正胎龄≥35W或出生后4~6周。Objective:To explore the clinical screening criteria and screening time for the first time according to birth weight and birth gestational age of premature infants.Methods:A total of 1 148 premature infants from NICU of the hospital from February 2008 to February 2011 were collected,bilateral indirect ophthalmoscope was used for fundus examination,related clinical data were collected for statistical analysis.Results:There was statistically significant difference in the incidence of threshold retinopathy of prematurity(ROP) among the infants with birth weight ≤1 000 g,1 001-1 250 g,1 251-1 500 g,1 501-1 750 g,1 751-2 000 g,and >2 000 g(χ2=201.54,P1 500 g decreased significantly.The area under ROC curve was the largest in the infants with birth weight=1 532.5 g;there was statistically significant difference in the incidence of threshold ROP among the infants with birth gestational age32 weeks decreased significantly ROC curve showed that the area was the largest in the infants with birth gestational age=32.07 weeks;the gestational weeks of 8 premature infants with threshold ROP whose correct gestational weeks was less than 35 weeks were 4-6 weeks.Conclusion:Birth weight≤1 500 g and birth gestational weeks≤32 weeks are screening indexes of ROP;the screening time for the first time was correct gestational weeks≥35 weeks or at 4-6 weeks after birth.厦门市科技计划项目〔350Z20114027

平行轴线齿轮的啮合特性研究

研究了平行轴线齿轮的啮合特性,包括滑动率、啮合模型和啮合频率;并与渐开线齿轮固有的节点冲击、动态传动误差和啮合冲击等特性进行比较。理论分析结果表明,平行轴线齿轮可以从根本上消除节点冲击、时变刚度对齿轮传动振动和噪声的影响;同时,平行轴线齿轮受到的啮合冲击频率较低。仿真实验结果表明,平行轴线齿轮滑动率为0,且具有稳态啮合的特性。为平行轴线齿轮的振动和噪声研究提供了理论基础,为其在齿轮变速器减振降噪领域的应用提供了依据

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