Background:Urolithiasis or renal stone formation occurs with three times higher frequency in males and decreases with age in parallel with the serum testosterone levels, suggesting a role played by male sex hormones. Androgens appear a promotion action and estrogens an inhibitory action on kidney stone formation in several animal models suggesting a study to be carried out to deduce the role played by serum testosterone in the formation of renal stones.Aim:The aim of this study is to define the involvement of serum total testosterone, free testosterone, and dihydrotestosterone in the pathogenesis of urolithiasis in males by comparing the results with healthy males with no present or past history of urolithiasis as controls.Materials and Methods:A case–control study was undertaken with 108 participants: 78 males diagnosed with urolithiasis and 30 age-matched healthy males.Results:The difference between mean age and body mass index of patients and controls were found to be nonsignificant. The total serum testosterone levels, serum dihydrotestosterone levels, were found to be higher in patients when compared to controls, and the difference was found to be significant. The levels of free testosterone and serum estradiol were also found to be higher in urolithiatic patients.Conclusion:The study demonstrates that elevated levels of serum testosterone and serum dihydrotestosterone might be involved in increased incidences of stone formation. The higher levels of estradiol do not seem to be a protective factor in males with urolithiasis with higher serum testosterone levels.

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Background:Gallstones have become a major health problem because of their silent manifestation and unclear pathogenesis. Although the association between the disturbed lipid metabolism and formation of gallstones has been elucidated in many studies, the effect of cholecystectomy on lipid profile has not been studied in detail.Aim:The aim of the present study was to study the effect of cholecystectomy on lipid levels in patients with gallstones.Materials and Methods:The study was conducted on 50 patients with gallstones and 30 healthy volunteers for comparison of lipid levels. Subsequently, cholecystectomy was conducted on patients with gallstones and pre- and post-operative lipid levels were compared.Results:There was a significant decrease in total cholesterol, and triglycerides levels and increase in high-density lipoprotein levels after 1 month of surgery, while low-density lipoprotein levels and very low-density lipoprotein were not statistically changed.Conclusion:Cholecystectomy can significantly improve lipid levels in patients with gallstones.

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Evolving from past black‐and‐white images, through present red‐green‐blue spectral colors, future remote imaging systems promise spectroscopic functionalities extending well beyond the visible wavelengths. This allows real‐time spectral information to be gathered from multiple wavelength bands that is applicable to numerous remote sensing spectroscopy/imaging applications and aids target recognition. This paper reviews the wavelength tunable microelectromechanical systems (MEMS) optical filter technologies developed for the important infrared and the emerging terahertz wavelength bands of the electromagnetic spectrum with the fabrication effort being enabled by the Western Australian Node of the Australian National Fabrication Facility. A low size, weight and power (SWaP) platform solution is demonstrated delivering mechanically robust, field‐portable, spectroscopic, chem/bio sensing suitable for deployment in remote sensing and imaging applications.

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High performance distributed Bragg reflectors (DBRs) are key elements to achieving high finesse MEMS-based Fabry-Pérot interferometers (FPIs). Suitable mechanical parameters combined with high contrast between the refractive indices of the constituent optical materials are the main requirements. In this paper, Germanium (Ge) and barium fluoride (BaF 2 ) optical thin-films have been investigated for mid-wave infrared (MWIR) and long-wave infrared (LWIR) filter applications. Thin-film deposition and fabrication processes were optimised to achieve mechanical and optical properties that provide flat suspended structures with uniform thickness and maximum reflectivity. Ge-BaF 2 -Ge 3-layer solid-material DBRs have been fabricated that matched the predicted simulation performance, although a degradation in performance was observed for wavelengths beyond 10 μm that is associated with optical absorption in the BaF 2 material. Ge-Air-Ge 3-layer air-gap DBRs, in which air rather than BaF 2 served as the low refractive index layer, were realized to exhibit layer flatness at the level of 10 to 20 nm across lateral DBR dimensions of several hundred micrometers. Measured DBR reflectance was found to be ≳90% over the entire wavelength range of the MWIR band and for the LWIR band up to a wavelength of 11 μm. Simulations based on the measured DBR reflectance indicates that MEMS-based FPIs are able to achieve a peak transmission of ≳90% over the entire MWIR band and up to 10 μm in the LWIR band, with a corresponding spectral passband of ≲50 nm in the MWIR and <80 nm in the LWIR.

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