Photochemical Properties of the Red-shifted Channelrhodopsin Chrimson

Color‐tuned variants of channelrhodopsins allow for selective optogenetic manipulation of different host cell populations. Chrimson is the channelrhodopsin with the longest wavelength absorbance maximum. We characterize its photochemical properties at different pH values corresponding to two protonation states of the counterion for the protonated Schiff base. Both states will lead to a functional channel opening, but the route is different as reflected in the photochemical states observed spectroscopically. The light‐induced isomerization kinetics change with the local electrostatic environment, becoming faster with the presence of an anionic counterion. The spectral effect is stronger on the ground‐state energy surface. From the excited state, a bifurcated pathway leads to the electronic ground state resulting in a pronounced excitation wavelength dependence. The subsequent steps in the photocycles at pH 6 and pH 9.5 differ in the accumulation of states with a protonated and deprotonated Schiff base, respectively, that can be correlated with the open channel. Therefore, different protonation states are preserved in the open and the initial states. Chrimson's photocycle at alkaline pH shows features observed in other rhodopsins without an internal proton donor to the Schiff base, but it accumulates an intermediate with an even longer lifetime reflecting slow recovery of the initial state

Activation of immune cell proteasomes in peripheral blood of smokers and COPD patients - implications for therapy.

Immune cells contain a specialised type of proteasome, i.e. the immunoproteasome, which is required for intracellular protein degradation. Immunoproteasomes are key regulators of immune cell differentiation, inflammatory activation and autoimmunity. Immunoproteasome function in peripheral immune cells might be altered by smoking and in COPD thereby affecting immune cell responses.We here analysed the expression and activity of proteasome complexes in peripheral blood mononuclear cells (PBMC) isolated from healthy male young smokers as well as from patients with severe COPD and compared them to matching controls. Proteasome expression was upregulated in COPD patients as assessed by RT-qPCR and mass spectrometry-based proteomics analysis. Proteasome activity was quantified using activity-based probes and native gel analysis. We observed distinct activation of immunoproteasomes in the peripheral blood cells of young male smokers and severely ill COPD patients. Native gel analysis and linear regression modeling confirmed robust activation and elevated assembly of 20S proteasomes, which correlated significantly with reduced lung function parameters in COPD patients. The immunoproteasome was distinctly activated in COPD patients upon inflammatory cytokine stimulation of PBMCs in vitro Inhibition of the immunoproteasome reduced proinflammatory cytokine expression in COPD-derived blood immune cells.Given the crucial role of chronic inflammatory signalling and the emerging involvement of autoimmune responses in COPD, therapeutic targeting of the immunoproteasome might represent a novel therapeutic concept for COPD

THE LUNA II 400KV ACCELERATOR

A second high current accelerator of 400 kV has been installed at the underground laboratory of Gran Sasso, called LUNA II. We describe this new facility as well as measurements of the proton beam characteristics: absolute energy, energy spread, and long-term energy stability. The absolute energy was determined to a precision of 7300 eV at Ep ¼ 130–400 keV using the energy of the capture g-ray transition of 12Cðp; gÞ13N as well as resonance energies at Ep ¼ 309–389 keV of 23Naðp; gÞ24Mg; 26Mgðp; gÞ27Al; and 25Mgðp; gÞ26Al: The resonance studies led to a proton energy spread of better than 100 eV and a long-term energy stability of 5 eV per hou

The LUNA II 400 kV accelerator

Abstract A second high current accelerator of 400 kV has been installed at the underground laboratory of Gran Sasso, called LUNA II. We describe this new facility as well as measurements of the proton beam characteristics: absolute energy, energy spread, and long-term energy stability. The absolute energy was determined to a precision of 7300 eV at E p ¼ 130-400 keV using the energy of the capture g-ray transition of 12 Cðp; gÞ 13 N as well as resonance energies at E p ¼ 309-389 keV of 23 Naðp; gÞ 24 Mg; 26 Mgðp; gÞ 27 Al; and 25 Mgðp; gÞ 26 Al: The resonance studies led to a proton energy spread of better than 100 eV and a long-term energy stability of 5 eV per hour.

A TOF-E detector for ERNA recoil separator

For improved cross-section measurements of the reaction 4He(3He,gamma )7Be in inverse kinematics, the recoil mass separator ERNA (European Recoil separator for Nuclear Astrophysics) is used to detect directly the 7Be recoils with high efficiency. The 7Be recoils are produced by the 4He projectiles in a windowless 3He gas target. ERNA fulfils the requirement to study the reaction over the center of mass energy range Ecm= 0.7-3 MeV. In the energy range Ecm=1.1-3 MeV ions identification is performed with Delta E-ERest telescope detector, while in the energy range Ecm= 0.7-1.1 MeV a TOF-E detector is needed. The commissioning of the TOF-E (Time of Flight-Energy) detector set up and the first observation of the 7Be recoils are reported