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Arrays of vertically aligned Si-nanopillars, with average diameters of 100 nm and 5 μm length, have been prepared by wet chemical etching of crystalline silicon in a special manner. Samples with smooth- and porous-walled nanopillars have been studied. In the case of the latter, Si-nanocrystals, passivated with SiO(x), decorating the surface of the nanopillars are identified by the means of TEM and FTIR. When excited by UV-blue light, the porous-walled Si-nanopillars are found to have a strong broad visible emission band around 1.8 eV with a nearly perfect Gaussian shape, μs luminescence lifetimes, minor emission polarization and a non-monotonic temperature dependence of luminescence. The Si-nanocrystal surface is found to be responsible for the luminescence. The red-shift of the emission maximum and the luminescence quenching induced by oxidation in UV-ozone confirm this assumption. A model of luminescence involving UV photon absorption by Si-nanocrystals with subsequent exciton radiative recombination on defect sites in SiO(x) covering Si-nanocrystals has been proposed. Possible applications of the nanopillar arrays are discussed.

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The outer geomagnetic field comprises the outer radiation belt, consisting of electrons with energies of 10•-10 • ev, and the unstable radiation zone. The outer radiation belt is bounded on its inner side by a gap, which is at various times located at a distance of 22-3.5 RB and in which a considerable precipitation ooe electrons from radiation belts occurs, possibly owing to a high intensity of electromagnetic waves. The boundary separating the outer radiation belt from the unstable radiation zone is at X • 71 ø and ~9 RB in the equatorial plane on the sunlit side, and at 7-8 R• in the equatorial plane on the nightside. Beyond this, the unstable radiation zone extend s• out to the magnetosphere boundary and up to X • 77 ø on the sunlit side, and out to 14-15 Rz on the nightside. The relatively rapid electron intensity variations with periods of 1-7 days are essentially absent at distances less than that of the outer belt but are distinctly seen in the outer belt. In the unstable radiation zone the intensity of electrons with energies of the order of 105 ev changes by several times, and good correlation is observed with the increase in K•. Analysis of the outer belt data shows that this belt is formed partly by electron diffusion into the magnetosphere (like the belt of protons with energies of 10•-10 • ev) and partly by the simultaneous acceleration of electrons at various distances from the earth. A comparison of electron intensity changes with the solar activity cycle shows little or no correlation for electrons with E6 > 40 key. The intensity of electrons with E6 > 500 key has changed significantly; in 1964 it was 30 times lower than in 1959. The absence of significant dependence of the diffusion coefficients for electrons with E ~ 10•--10 • ev on the. phase of the solar activity cycle shows that the relatively weak magnetic disturbances that do not change with the phase of the cycle are of major importance in diffusion. This suggests that these magnetic disturbances appear at great distances from the sun because of the instabilities of plasma itself and, 257 258 ¾ERNO¾ ET AL. boundary, and on the dark side the outer belt electrons were observed up to the boundary of stable trapping. It appeared that the outer belt electron fluxes were subject to considerable fluctuations, whereas the protons fluxes were much more stable.At present the protons of the outer and inner belt have been fairly well explained as due to neutron decay and betatron acceleration during diffusion from the ou•r magnetospheric regions. These mechanisms have also been used to explain the formation of the radiation belt electron component. This report presents experimental data which show that it is necessary t• consider additional mechanisms of particle acceleration and transfer.

BackgroundPrimary hyperparathyroidism (PHPT) is a relatively rare disorder among children, adolescents and young adults. Its development at an early age is suspicious for hereditary causes, though the need for routine genetic testing remains controversial.ObjectiveTo identify and describe hereditary forms of PHPT in patients with manifestation of the disease under 40 years of age.DesignWe enrolled 65 patients with PHPT diagnosed before 40 years of age. Ten of them had MEN1 mutation, and PHPT in them was the first manifestation of multiple endocrine neoplasia type 1 syndrome.MethodsThe other fifty-five patients underwent next-generation sequencing (NGS) of a custom-designed panel of genes, associated with PHPT (MEN1, CASR, CDC73, CDKN1A, CDKN1B, CDKN1C, CDKN2A, CDKN2C, CDKN2D). In cases suspicious for gross CDC73 deletions multiplex ligation-dependent probe amplification was performed.ResultsNGS revealed six pathogenic or likely pathogenic germline sequence variants: four in CDC73 c.271C>T (p.Arg91*), c.496C>T (p.Gln166*), c.685A>T (p.Arg229*) and c.787C>T (p.Arg263Cys); one in CASR c.3145G>T (p.Glu1049*) and one in MEN1 c.784-9G>A. In two patients, MLPA confirmed gross CDC73 deletions. In total, 44 sporadic and 21 hereditary PHPT cases were identified. Parathyroid carcinomas and atypical parathyroid adenomas were present in 8/65 of young patients, in whom CDC73 mutations were found in 5/8.ConclusionsHereditary forms of PHPT can be identified in up to 1/3 of young patients with manifestation of the disease at <40 years of age. Parathyroid carcinomas or atypical parathyroid adenomas in young patients are frequently associated with CDC73 mutations.

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