Enhancing the axial resolution of quantum optical coherence tomography by chirped quasi-phase matching

We show theoretically that a chirped quasi-phase-matching nonlinear crystal structure can significantly enhance the axial resolution in quantum optical coherence tomography by increasing the spectral width of the generated entangled photon pairs. For pulsed pumps we show how the pump-pulse duration affects the maximum resolution attainable.     

Analyse der Luft

Ohne Zusammenfassung     

Photocounting statistics of radiation propagating through passive and active random media

The photocounting statistics of radiation propagating through active, quadratic random media and through passive media are considered on the basis of a recently developed quantum dynamic theory. We show that the counting statistics for lossless random active media and those for passive weakly-inhomogeneous random media are similar, although there are some differences. The peak of the photocounting distribution shifts to lower count numbern and is found to broaden with increasing turbulence level, as in the case of passive media. In lossy active media, the shift of the peak to lowern is more pronounced, in pumped active media below threshold it is less so, and in pumped active media above threshold, there is a shift of the peak to highern as a consequence of self-radiation. Severe broadening occurs in this latter case. Photocounting statistics for special states of the incident field are also discussed.     

gR and gK factors in deformed nuclei

The static and dynamic magnetic dipole moments of odd-mass and even-mass nuclei with 150R and intrinsic g-factors g_K.     

Heterodyne detection of random Gaussian signals in the optical and infrared: optimization of pulse duration

The performance of a heterodyne system in estimating the mean intensity of a gaussian random signal depends on the mean number of photocarriers released by the signal radiation in its coherence volume (degeneracy parameter). In a pulsed radar, this parameter can be manipulated by varying the pulse duration while keeping the mean number of signal photocarriers constant. Furthermore, in a number of situations of practical interest, an optimal pulse duration exists, corresponding to a degeneracy parameter of unity. Heterodyne and direct detection are compared for this case, and direct detection is found to be superior in the strong-signal limit.     

Kurze Originalmitteilungen Herstellung von [9,10-3II]-Stearinsäure

Katalytische Hydrierung von Oktadeken-(9)-säure (Ölsäure; I) mit H₂; in Gegenwart von Palladiummohr führt quantitativ zur Oktadekansäure (Stearinsäure; Ha). Beide Säuren unterscheiden sich bei Anwendung herkömmlicher ehromatographischer Hilfsmittel nicht. Beispielsweise laufen sowohl I als auch IIa     

Antisense-mediated isoform switching of steroid receptor coactivator-1 in the central nucleus of the amygdala of the mouse brain

Background

Antisense oligonucleotide (AON)-mediated exon skipping is a powerful tool to manipulate gene expression. In the present study we investigated the potential of exon skipping by local injection in the central nucleus of the amygdala (CeA) of the mouse brain. As proof of principle we targeted the splicing of steroid receptor coactivator-1 (SRC-1), a protein involved in nuclear receptor function. This nuclear receptor coregulator exists in two splice variants (SRC-1a and SRC-1e) which display differential distribution and opposing activities in the brain, and whose mRNAs differ in a single SRC-1e specific exon.

Methods

For proof of principle of feasibility, we used immunofluorescent stainings to study uptake by different cell types, translocation to the nucleus and potential immunostimulatory effects at different time points after a local injection in the CeA of the mouse brain of a control AON targeting human dystrophin with no targets in the murine brain. To evaluate efficacy we designed an AON targeting the SRC-1e-specific exon and with qPCR analysis we measured the expression ratio of the two splice variants.

Results

We found that AONs were taken up by corticotropin releasing hormone expressing neurons and other cells in the CeA, and translocated into the cell nucleus. Immune responses after AON injection were comparable to those after sterile saline injection. A successful shift of the naturally occurring SRC-1a:SRC-1e expression ratio in favor of SRC-1a was observed, without changes in total SRC-1 expression.

Conclusions

We provide a proof of concept for local neuropharmacological use of exon skipping by manipulating the expression ratio of the two splice variants of SRC-1, which may be used to study nuclear receptor function in specific brain circuits. We established that exon skipping after local injection in the brain is a versatile and useful tool for the manipulation of splice variants for numerous genes that are relevant for brain function.     

Transfer measurements for the Ti+Ni systems at near barrier energies

Large enhancements have been observed in the sub-barrier fusion cross sections for Ti+Ni systems in our previous studies. Coupled channel calculations incorporating couplings to 2⁺ and 3⁻ states failed to explain these enhancements completely. A possibilty of transfer channels contributing to the residual enhancements had been suggested. In order to investigate the role of relevant transfer channels, measurements of one- and two-nucleon transfer were carried out for ^46,48Ti+⁶¹Ni systems. The present paper gives the results of these studies.     

Announcement

We discuss the generation of stationary sub-Poisson light by selective deletion from cascaded atomic emissions. As a particular example we show that, under appropriate conditions, the green/violet cascade from an atomic beam of Ca can be made to produce low-flux violet light that is weakly sub-Poisson. In principle, the technique can be applied to other two-photon processes such as positron annihilation radiation.