SS Ari: a shallow-contact close binary system

Two CCD epochs of light minimum and a complete R light curve of SS Ari are presented. The light curve obtained in 2007 was analyzed with the 2003 version of the W-D code. It is shown that SS Ari is a shallow contact binary system with a mass ratio $q=3.25$ and a degree of contact factor f=9.4(\pm0.8%). A period investigation based on all available data shows that there may exist two distinct solutions about the assumed third body. One, assuming eccentric orbit of the third body and constant orbital period of the eclipsing pair results in a massive third body with $M_3=1.73M_{\odot}$ and P_3=87.0$yr. On the contrary, assuming continuous period changes of the eclipsing pair the orbital period of tertiary is 37.75yr and its mass is about$0.278M_{\odot}$. Both of the cases suggest the presence of an unseen third component in the system.Comment: 28 pages, 9 figures and 5 table

Unbound states of 32Cl and the 31S(p,\gamma)32Cl reaction rate

The 31S(p,\gamma)32Cl reaction is expected to provide the dominant break-out path from the SiP cycle in novae and is important for understanding enrichments of sulfur observed in some nova ejecta. We studied the 32S(3He,t)32Cl charge-exchange reaction to determine properties of proton-unbound levels in 32Cl that have previously contributed significant uncertainties to the 31S(p,\gamma)32Cl reaction rate. Measured triton magnetic rigidities were used to determine excitation energies in 32Cl. Proton-branching ratios were obtained by detecting decay protons from unbound 32Cl states in coincidence with tritons. An improved 31S(p,\gamma)32Cl reaction rate was calculated including robust statistical and systematic uncertainties

Rates for the reactions antiproton-proton --> pi phi and gamma phi

We study antiproton-proton annihilation at rest into $\pi\phi$ and $\gamma\phi$. Rescattering by $\overline{K^*}K+K^*\overline{K}$ and $\rho^{+}\rho^{-}$ for $\overline{p}p\rightarrow\pi\phi$ states is sizable, of order $(0.90\, {\rm to}\,2.6)\times 10^{-4}$ in the branching ratio, but smaller than experiment. For $\overline{p}p\rightarrow\gamma\phi$ the rescattering contributions are negligible, but the $\gamma\phi$ channel is well explained by a $\rho\phi$ intermediate state combined with vector meson dominance.Comment: 12 pages, plain latex, 2 postscript figures available upon request, PSI-PR-93-2

Involvement of GPR17 in neuronal fibre outgrowth

Characterization of new pharmacological targets is a promising approach in research of neurorepair mechanisms. The G protein-coupled receptor 17 (GPR17) has recently been proposed as an interesting pharmacological target, e.g., in neuroregenerative processes. Using the well-established ex vivo model of organotypic slice co-cultures of the mesocortical dopaminergic system (prefrontal cortex (PFC) and substantia nigra/ventral tegmental area (SN/VTA) complex), the influence of GPR17 ligands on neurite outgrowth from SN/VTA to the PFC was investigated. The growth-promoting effects of Montelukast (MTK; GPR17- and cysteinyl-leukotriene receptor antagonist), the glial cell line-derived neurotrophic factor (GDNF) and of two potent, selective GPR17 agonists (PSB-16484 and PSB-16282) were characterized. Treatment with MTK resulted in a significant increase in mean neurite density, comparable with the effects of GDNF. The combination of MTK and GPR17 agonist PSB-16484 significantly inhibited neuronal growth. qPCR studies revealed an MTK-induced elevated mRNA-expression of genes relevant for neuronal growth. Immunofluorescence labelling showed a marked expression of GPR17 on NG2-positive glia. Western blot and RT-qPCR analysis of untreated cultures suggest a time-dependent, injury-induced stimulation of GPR17. In conclusion, MTK was identified as a stimulator of neurite fibre outgrowth, mediating its effects through GPR17, highlighting GPR17 as an interesting therapeutic target in neuronal regeneration

Design of an Activity-Based Probe for Human Neutrophil Elastase: Implementation of the Lossen Rearrangement To Induce Förster Resonance Energy Transfers.

Human neutrophil elastase is an important regulator of the immune response and plays a role in host defense mechanisms and further physiological processes. The uncontrolled activity of this serine protease may cause severe tissue alterations and impair inflammatory states. The design of an activity-based probe for human neutrophil elastase reported herein relies on a sulfonyloxyphthalimide moiety as a new type of warhead that is linker-connected to a coumarin fluorophore. The inhibitory potency of the activity-based probe was assessed against several serine and cysteine proteases, and the selectivity for human neutrophil elastase (Ki = 6.85 nM) was determined. The adequate fluorescent tag of the probe allowed for the in-gel fluorescence detection of human neutrophil elastase in the low nanomolar range. The coumarin moiety and the anthranilic acid function of the probe, produced in the course of a Lossen rearrangement, were part of two different Förster resonance energy transfers

Distribution and consequences of VKORC1 polymorphisms in Germany

Runge, M., Von Keyserlingk, M., Braune, S., Freise, J., Eiler, T., Plenge-Bönig, A., Becker, D., Pelz, H.-J., Esther, A., Rost, S., Müller, C.R

Microwave stray radiation losses in vacuum windows

Vacuum windows are required in magnetically confined fusion experiments to provide possibilities to observe the plasma in a wide range of electromagnetic wavelengths. The window disk consists of a dielectric, e.g. Fused Silica (SiO$_2$), Sapphire or Chemically Vapourised Diamond (CVD). As electromagnetic waves pass through the disk, a fraction of the beam power is dissipated resulting in a temperature increase of the disk. In Electron Cyclotron Waves (ECW) heated plasmas the dissipation in the window disk can be very high. The computation of dielectric losses for a collimated beam with known incidence angle, polarisation and loss tangent (measure for the intrinsic dielectric loss) is well established. However, the dielectric losses in diagnostic windows mostly result from microwave stray radiation, which results from a modest, but inevitable, fraction of non-absorbed ECW. This fraction diffuses in the vessel by many reflections into rays with random k-vector and with random polarisation. In this work the thermal load on the window disk by microwave stray radiation is assessed. The load by a collimated beam is studied as a function of incidence angle and polarisation allowing to average over a distribution of incident rays. An experiment was commissioned measuring the loss tangent of a number of commercially available SiO$_2$ disks at low power in an open resonator, and subsequently measuring the dielectric heating of these disks at high power stray radiation using the facility ’MISTRAL’ at Wendelstein-7X. The experimental results are compared to modelling and it is demonstrated that, in the parameter range considered, single-pass fractional absorption may be applied while taking a safety margin that arises from the minima and maxima due to multiple reflections