A highly stable monolithic enhancement cavity for second harmonic generation in the ultraviolet

We present a highly stable bow-tie power enhancement cavity for critical second harmonic generation (SHG) into the UV using a Brewster-cut β-BaB2O4 (BBO) nonlinear crystal. The cavity geometry is suitable for all UV wavelengths reachable with BBO and can be modified to accommodate anti-reflection coated crystals, extending its applicability to the entire wavelength range accessible with non-linear frequency conversion. The cavity is length-stabilized using a fast general purpose digital PI controller based on the open source STEMlab 125-14 (formerly Red Pitaya) system acting on a mirror mounted on a fast piezo actuator. We observe 130 h uninterrupted operation without decay in output power at 313 nm. The robustness of the system has been confirmed by exposing it to accelerations of up to 1 g with less than 10% in-lock output power variations. Furthermore, the cavity can withstand 30 min of acceleration exposure at a level of 3 grms without substantial change in the SHG output power, demonstrating that the design is suitable for transportable setups. © 2018 Author(s)

Hematobiochemical, immunological, antioxidant status, and residues of flumethrin following weekly dermal application in goats

Flumethrin is used extensively in livestock periodically, which may cause adverse effect in goats and subsequently to human being through food chain. Flumethrin at 1.0% solution was applied weekly dermally for 84 days and hematobiochemical as well as immunological parameters, anti-oxidant status, liver enzymes, and tissue residues in goats were estimated. Flumethrin did not produce changes in hemogram except decreased total leukocyte count. Serum protein level was decreased, but serum AST and ALT activities were increased at the end of the study period. IgG level was decreased from the last 2 weeks. But flumethrin did not produce any effect on antioxidant status, as evident from nonsignificant changes in catalase, lipid peroxidation, superoxide dismutase, and reduced glutathione level in liver. Liver AST and ALT activities increased and cytochrome P450 content decreased on day 85. Histopathological study revealed mild changes in liver. Low level of residues of flumethrin was detected in vital tissues following high-performance liquid chromatographic (HPLC) analysis. Flumethrin could not be detected in tissues after 21 days withdrawal period. It may be concluded that flumethrin produces mild changes in various biochemical and immunological parameters from the last 2 weeks of study period and did not have a tendency to accumulate in the different tissues following weekly dermal application for 3 months.</p