Site-controlled growth of InP/GaInP quantum dots on GaAs substrates.

A technology platform for the epitaxial growth of site-controlled InP quantum dots (QDs) on GaAs substrates is presented. Nanoholes are patterned in a GaInP layer on a GaAs substrate by electron beam lithography and dry chemical etching, serving as QD nucleation centers. The effects of a thermal treatment on the structured surfaces for deoxidation are investigated in detail. By regrowth on these surfaces, accurate QD positioning is obtained for square array arrangements with lattice periods of 1.25 µm along with a high suppression of interstitial island formation. The optical properties of these red-emitting QDs (λ ~ 670 nm) are investigated by means of ensemble- and micro-photoluminescence spectroscopy at cryogenic temperatures.

The structural and optical characterization of high areal density Ga(x)In(1-x)P quantum dots on GaP.

We present a study of the growth, morphology and optical properties of Ga(x)In(1-x)P quantum dots (QDs) grown by molecular beam epitaxy (MBE) for various Ga concentrations x. QD areal densities up to 10(11) cm(-2) have been achieved showing strong dependence on the amount of gallium supplied. Structural properties are evaluated using scanning electron microscopy (SEM) and atomic force microscopy (AFM) and are related to photoluminescence properties of the QDs. Both structural and optical properties are promising for future applications of the herein reported QDs in visible wavelength optoelectronic devices.

[Hypophosphatemia after successful transplantation of the kidney. Clinico-experimental study]. / Hypophosphatämie nach erfolgter Transplantation der Niere. Klinisch-experimentelle Untersuchung.

The dynamic of indices changes of phosphorus treatment with nefrons in 16 patients after kidney transplantation was studied. The transitory hypophosphatemia accompanied with urine was typical in the majority of patients. The decrease of reabsorption and elevation of phosphorus clearance were noted. In a number of cases the phosphatemia level was increased due to reduction of prednisolone doses. It was experimentally revealed that prednisolone reduces the phosphorus absorption in intestine at 25% and the treatment by 1,25-dihydroxy-vitamin D3 and 1 alpha-hydroxyvitamin D3 promotes the normalization of this process.

[State of order, properties and dynamics of structure in shear-crystallized ointments (author's transl)]. / Ordnungszustand, Eigenschaften und Strukturdynamik in scherkristallisierten salben.

Using polyethylene-ointments the influence of different stirring rates upon the course of melt-congealing and upon the forming of rheological properties was investigated. Shearing disturbs the process of ordering in the solid phase and causes a higher strength of the ointment. During storage the viscosity increases in the nonsheared ointments and it decreases in the sheared ones. Both systems tend to form a dynamic equilibrium of order characterized by relative intensive lattive defects in the solid phase of the gel matrix.

[Preoperative phase of colonic surgery (author's transl)]. / Die präoperative Phase in der Kolonchirurgie.

The existing possibilities to prepare colon and rectum for surgery are discussed, optimal nutrition just before operation is particularly stressed. The efficiency of oral and parenteral antimicrobial prophylaxis ist pointed out. Apart from contra-indications, orthograde lavage of the bowel is the method of choice.