Both systemic and local application of Granulocyte-colony stimulating factor (G-CSF) is neuroprotective after retinal ganglion cell axotomy

Background  

The hematopoietic Granulocyte-Colony Stimulating Factor (G-CSF) plays a crucial role in controlling the number of neutrophil progenitor cells. Its function is mediated via the G-CSF receptor, which was recently found to be expressed also in the central nervous system. In addition, G-CSF provided neuroprotection in models of neuronal cell death. Here we used the retinal ganglion cell (RGC) axotomy model to compare effects of local and systemic application of neuroprotective molecules.     

Pion-nucleon vertex function with an off-shell nucleon

We present a model calculation for the π-N vertex function in the case in which there is a single off-mass-shell nucleon and a (nearly) on-mass-shell pion. We find very strong effects due to the P₁₁ resonance at 1470 MeV. We provide a simple parametrization of the vertex function in the case that at least one nucleon is on its mass shell.     

Luminescence of silicon films on sapphire irradiated with high-energy particles

Using low-temperature (4.2–78 K) photoluminescence, we study the processes of defect formation in silicon films on sapphire irradiated with high-energy particles (electrons, γ-quanta of⁶⁰Co). It is established that carbon atoms, as a residual process impurity, participate in the formation of luminescence centers stable up to annealing temperatures of about 550 K. For carbon-containing centers we reveal a shift in the spectral lines relative to their position in spectra of single-crystal silicon. It is proposed that this spectral shift is associated with the presence of internal stresses of about 5·10⁸ N/m² in the silicon films. Institute of Solid-State Physics and Semiconductors, National Academy of Sciences of Belarus, 17, P. Brovka Str., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskefii, Vol. 66, No. 3, pp. 383–386, May–June, 1999.     

CVT法生长GaP多晶

阐述了CVT(化学气相输运)法生长GaP的基本反应和输运速度,采用CVT法生长出了GaP多晶.设计了石英管的结构以制造出一个局部的低温区域,防止了GaP在管壁的生长.生长出的GaP多晶相对密度为98;,红外透过率达到30;,努普硬度为611kg/mm2.散射颗粒测试表明主要的光散射颗粒为多晶中存在的孔隙.     

Acoustooptical system for imaging TV information by using a copper vapor laser

A laser acoustooptical system for projecting TV images onto a large-area screen is developed and produced. A copper-vapor laser with an average power of 20 W is used in it as a radiation source. Images are formed by using green and orange spectral lines. The exposure of a whole TV line on a screen in a time corresponding to the laser pulse duration is the principle governing the operation of the system. A TV line is formed by an acoustooptical modulator (AOM) designed on the basis of a paratellurite (TeO₂) crystal. Frame scanning of an image is performed by using an electromagnetic galvanometer. A high line and frame resolution of about 2000×1000 pixels in the TV standard is obtained. The system makes it possible to form a TV image of size greater than 20 m² with brightness of about 50 cd/m² at a distance of 20 to 100 m. Operating principles of the system and requirements imposed on the laser, the AOM, and other elements are considered.