Finite Element Analysis of the Distribution Parameters of a Metal Dot Array in a SAW Gyroscope

A surface acoustic wave (SAW) gyroscope has many unique advantages, but a low detection sensitivity limits its development. Previous studies have shown that adding a metal dot array to the acoustic wave propagation path of the SAW delay line can enhance the Coriolis force and further improve sensitivity. Therefore, in order to optimize the detection sensitivity performance of the sensor, 128°YX-LiNbO3, ST-X Quartz and X112°Y-LiTaO3 piezoelectric substrates were selected by finite element method to analyze the influence of the metal dot array size on the SAW gyroscopic effect in this paper. The most suitable metal dot size for 128°YX-LiNbO3 and X112°Y-LiTaO3 obtained by simulation are 5/16λ and 1/16λ, respectively; for example, when the normalized angular velocity is 1 × 10−3, the SAW gyroscopic effect factor g of the two piezoelectric substrates distributing the optimum size metal dots can reach 22.4 kHz and 5.2 kHz. For ST-X quartz, there is a threshold between the rotation speed of the substrate and the optimum size of the metal dot. When the rotating speed is lower than the threshold, the SAW gyroscopic effect is strongest when the metal dot size is 3/16λ; otherwise, the SAW gyroscopic effect is strongest when the size is 11/16λ. These research results provide new ideas for improvement of the SAW gyroscope

Isolates of Cryptococcus Neoformans from Non-HIV and Non-Transplant Hospitalized Patients

A retrospective cross-sectional study for patients with confirmed Cryptococcus neoformans meningitis (CM) in non-HIV-infected and non-transplant hosts in two class-A tertiary hospitals in Guangzhou, China is reported. 181 CM patients were enrolled during the study period, 48% (87/181) of which died. Underlying diseases were risk factor associated with higher mortality, among which diabetes mellitus ranked first for the incidence of CM. The mortality was not related to antifungal drug susceptibility. All strains were considered susceptible to amphotericin B, although interpretative breakpoints for amphotericin B have not yet been established. According to the CLSI guidelines, most of the strains in our study were susceptible to voriconazole, fluconazole, fluorocytosine and dose-dependently susceptible to itraconazle

Photodynamic therapy combined with antifungal drugs against chromoblastomycosis and the effect of ALA-PDT on Fonsecaea in vitro.

BACKGROUND:Chromoblastomycosis is a chronic skin and subcutaneous fungal infection caused by dematiaceous fungi and is associated with low cure and high relapse rates. In southern China, Fonsecaea monophora and Fonsecaea pedrosoi are the main causative agents. PRINCIPAL FINDINGS:We treated 5 refractory and complex cases of chromoblastomycosis with 5-aminolevulinic acid photodynamic therapy (ALA-PDT) combined with oral antifungal drugs. The lesions improved after 4 to 9 sessions of ALA-PDT treatment at an interval of one or two weeks, and in some cases, mycological testing results became negative. The isolates were assayed for susceptibility to antifungal drugs and ALA-PDT in vitro, revealing sensitivity to terbinafine, itraconazole and voriconazole, with ALA-PDT altering the cell wall and increasing reactive oxygen species production. CONCLUSIONS:These results provide the basis for the development of a new therapeutic approach, and ALA-PDT combined with oral antifungal drugs constitutes a promising alternative method for the treatment of refractory and complex cases of chromoblastomycosis