Solid-state laser system for laser cooling of Sodium

We demonstrate a frequency-stabilized, all-solid laser source at 589 nm with up to 800 mW output power. The laser relies on sum-frequency generation from two laser sources at 1064 nm and 1319 nm through a PPKTP crystal in a doubly-resonant cavity. We obtain conversion efficiency as high as 2 W/W^2 after optimization of the cavity parameters. The output wavelength is tunable over 60 GHz, which is sufficient to lock on the Sodium D2 line. The robustness, beam quality, spectral narrowness and tunability of our source make it an alternative to dye lasers for atomic physics experiments with Sodium atoms

An all-solid-state laser source at 671 nm for cold atom experiments with lithium

We present an all solid-state narrow line-width laser source emitting $670\,\mathrm{mW}$ output power at $671\,\mathrm{nm}$ delivered in a diffraction-limited beam. The \linebreak source is based on a fre-quency-doubled diode-end-linebreak pumped ring laser operating on the ${^4F}_{3/2} \rightarrow {^4I}_{13/2}$ transition in Nd:YVO$_4$. By using periodically-poled po-tassium titanyl phosphate (ppKTP) in an external build-up cavity, doubling efficiencies of up to 86% are obtained. Tunability of the source over $100\,\rm GHz$ is accomplished. We demonstrate the suitability of this robust frequency-stabilized light source for laser cooling of lithium atoms. Finally a simplified design based on intra-cavity doubling is described and first results are presented

Tetanus neurotoxin HCC protein commits T cell to IFN-γ producing cells

A protective response against tetanus toxin and toxoid demands efficient specific T cell and B cell responses. Tetanus neurotoxin (TeNT), a 150 kDa polypeptide, is the main cause of tetanus disease. TeNT consists of two structurally distinct chains, a 50 kDa N-terminal light (L) and a 100 kDa C-terminal heavy (H) chain. C-terminal heavy (H) chain (fragment C) has two sub-domains named as proximal HCN and carboxy sub-domain or HCC. Beside neural binding property, HCC has been recently found as an immunodominant module of TeNT. In the present study, we investigated the effects of recombinant HCC (rHCC) on the expression of lineage specific transcription factors and secretion of a panel of functional cytokines including IFN-γ, IL-4, and IL-17 from purified human T cells. Our results revealed that T-bet transcript level, as TH1 specific transcription factor, was significantly increased in the cells treated with 10 and 20 μg/ml of rHCC following 48 h treatment(p < 0.05). Treated purified human T cells with rHCC showed significant increase in IFN-γ mRNA level and cytokine secretion, but not IL-4 and IL-17, following 48 h treatment. In conclusion, our results showed that treatment of T cells with r HCC resulted in development of Th1 lineage phenotype, which might lead to a specific and protective antibody mediated response against tetanus toxin. © 2016 by the C.M.B. Association. All rights reserved