| 2 | Influence of ground effect on flow field structure and aerodynamic noise of high-speed trains显示文摘The simulation of the ground effect has always been a technical difficulty in wind tunnel tests of high-speed trains.In this paper,large eddy simulation and the curl acoustic integral equation were used to simulate the flow-acoustic field results of high-speed trains under four ground simulation systems(GSSs):“moving ground+rotating wheel”,“stationary ground+rotating wheel”,“moving ground+stationary wheel”,and“stationary ground+stationary wheel”.By comparing the fluid-acoustic field results of the four GSSs,the influence laws of different GSSs on the flow field structure,aero-acoustic source,and far-field radiation noise characteristics were investigated,providing guidance for the acoustic wind tunnel testing of high-speed trains.The calculation results of the aerodynamic noise of a 350 km/h high-speed train show that the moving ground and rotating wheel affect mainly the aero-acoustic performance under the train bottom.The influence of the rotating wheel on the equivalent sound source power of the whole vehicle was not more than 5%,but that of the moving ground slip was more than 15%.The average influence of the rotating wheel on the sound pressure level radiated by the whole vehicle was 0.3 dBA,while that of the moving ground was 1.8 dBA. | Xiaoming TAN Linli GONG Xiaohong ZHANG Zhigang YANG | 2024 | Journal of Zhejiang University-Science A(Applied Physics & Engineering)2024，25，2： | 0 |
| 3 | Existing tests vs. novel non-invasive assays for detection of invasive aspergillosis in patients with respiratory diseases显示文摘Background: Although existing mycological tests (bronchoalveolar lavage [BAL] galactomannan [GM], serum GM, serum (1,3)-β-D-glucan [BDG], and fungal culture) are widely used for diagnosing invasive pulmonary aspergillosis (IPA) in non-hematological patients with respiratory diseases, their clinical utility in this large population is actually unclear. We aimed to resolve this clinical uncertainty by evaluating the diagnostic accuracy and utility of existing tests and explore the efficacy of novel sputum-basedAspergillus assays.Methods: Existing tests were assessed in a prospective and consecutive cohort of patients with respiratory diseases in West China Hospital between 2016 and 2019 while novel sputum assays (especially sputum GM andAspergillus-specific lateral-flow device [LFD]) in a case-controlled subcohort. IPA was defined according to the modified European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria. Sensitivity and specificity were computed for each test and receiver operating characteristic (ROC) curve analysis was performed.Results: The entire cohort included 3530 admissions (proven/probable IPA=66, no IPA=3464) and the subcohort included 127 admissions (proven/probable IPA=38, no IPA=89). Sensitivity of BAL GM (≥1.0 optical density index [ODI]: 86% [24/28]) was substantially higher than that of serum GM (≥0.5 ODI: 38% [39/102]) (χ^(2)=19.83,P<0.001), serum BDG (≥70 pg/mL: 33% [31/95]) (χ^(2)=24.65,P<0.001), and fungal culture (33% [84/253]) (χ^(2)=29.38,P<0.001). Specificity varied between BAL GM (≥1.0 ODI: 94% [377/402]), serum GM (≥0.5 ODI: 95% [2130/2248]), BDG (89% [1878/2106]), and culture (98% [4936/5055]). Sputum GM (≥2.0 ODI) had similar sensitivity (84% [32/38]) (Fisher’s exactP=1.000) to and slightly lower specificity (87% [77/89]) (χ^(2)=5.52,P=0.019) than BAL GM (≥1.0 ODI). Area under the ROC curve values were comparable between sputum GM (0.883 [0.812-0.953]) and BAL GM (0.901 [0.824-0.977]) (P=0.734). Sputum LFD had similar specificity (91% [81/89]) (χ^(2)=0.89,P=0.345) to and lower sensitivity (63% [24/38]) (χ^(2)=4.14,P=0.042) than BAL GM (≥1.0 ODI), but significantly higher sensitivity than serum GM (≥0.5 ODI) (χ^(2)=6.95,P=0.008), BDG (χ^(2)=10.43,P=0.001), and fungal culture (χ^(2)=12.70,P<0.001).Conclusions: Serum GM, serum BDG, and fungal culture lack sufficient sensitivity for diagnosing IPA in respiratory patients. Sputum GM and LFD assays hold promise as rapid, sensitive, and non-invasive alternatives to the BAL GM test. | Wei Xiao Longyi Du Linli Cai Tiwei Miao Bing Mao Fuqiang Wen Peter Gerard Gibso Deying Gong Yan Zeng Mei Kang Xinmiao Du Junyan Qu Yan Wang Xuemei Liu Ruizhi Feng Juanjuan Fu | 2022 | Chinese Medical Journal2022，，13： | 0 |
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