Three-dimensionally confined excitons and biexcitons in submonolayer-CdSe/ZnSe superlattices

We report on structural and optical investigations of submonolayer-CdSe/ZnSe superlattices with varying thicknesses of the ZnSe spacer layers. High-resolution electron microscopy images demonstrate the formation of two-dimensional nanoscale CdSe islands for submonolayer-CdSe depositions. The vertical island arrangement is anti-correlated for spacer layer thicknesses exceeding 30Å, while predominantly vertically correlated growth occurs for thinner spacers. The different vertical ordering of the CdSe islands results in two clearly distinguishable lines in photoluminescence and optical reflectance spectra, which are attributed to excitons localized in quantum dots (QDs) formed by vertically coupled and uncoupled (Cd,Zn)Se islands, respectively. δ-like emission of single QDs is demonstrated and the different carrier localization in uncoupled and coupled QDs is reflected in the polarization of the edge emission. Stimulated emission and resonant waveguiding effects are observed for both states. At the highest excitation densities, we observe saturation of the stimulated emission in edge geometry attributed to saturation of localized states.     

The effect of nitrate and nitrite on the respiration and cytochrome system of Rhizobium lupini]

Chromosome replication has been analysed in four species of Chilocorus. In C. ORBUS Csy., C. tricyclus Smith, and C. hexacyclus Smith, centric regions of all chromosomes are last to replicate, preceded in order by heterochromatic arms and euchromatic arms. In C. stigma Say, very late replication of centric regions can be detected only in otherwise wholly euchromatic chromosomes (= monophasics); in chromosomes with one arm heterochromatic ( = disphasics), these arms are last to replicate. Based on pachytene bivalent morphology and chromosome banding patterns, and supported by autoradiographic data, models are presented for the general organisation of Chilocorus chromosomes. All chromosomes in the first three species are subdivided into euchromatic arm, centric heterochromatin, and either a second euchromatic are (monophasics) or a heterochromatic arm (diphasics). Chilocorus stigma diphasics apparently lack distinct centric organisation, and are therefore divided into euchromatic and heterochromatic arms only.     

Changes of peripheral blood flow in patients with cancer of the lungs, esophagus and cardia under the effect of anesthesia and surgery

The authors report the data on changes in peripheral circulation, depending on the kind of anesthesia, the amount of operative blood loss, alterations in circulating blood volume and localization of tumor in patients with cancer of the lung, esophagus and cardia. Totally, 35 patients (15--lung cancer, 10--esophageal cancer, 10--cancer of the cardia) were explored. In 25 cases fluothane was used as the main anesthetic, in 10--neuroleptanalgesia. The state of peripheral circulation was estimated by the period semielimination of radioactive xenon-133 from the muscle depot. It was found that alterations in peripheral circulation were not dependent on tumor localization, the use of fluothane and neuroleptanalgesia is associated with similar changes in peripheral blood flow and, finely, an increased loss of blood results in more pronounced alterations in peripheral circulation.     

Protein reabsorption by cells of the proximal kidney tubules in chronic diffuse glomerulonephritis depending on the degree of proteinuria

In a study of 80 cases of lymphogranuloma venereum (LGV), minocycline hydrochloride (Minocin) was found to be an effective drug in the treatment of all stages of LGV, including complicated ones. In late cases adjuvant treatment was used in addition to the antibiotic. Healing time in uncomplicated cases was less than 10 days. In complicated cases, both early and late, healing took about 2 to 3 weeks. Reactions to the drug were not significant.     

Morphological effects in rats following a 22-day space flight

A morphological examination of 27 rats flown onboard the biosatellite and sacrificed on the 1st-2nd and 26-27th postflight days demonstrated no significant changes in the structural organization of the vital organs and systems of the animal body. It was, however, found that the space exposure induced morphologically detectable changes in the musculo-skeletal system, hemo- and lymphopoiesis, hypothalamic-pituitary-adrenal system and the juxtaglomerular apparatus of the kidneys. The changes were reversible and nonspecific, and could be seen in animals exposed to ground-based hypokinetic and other stress experiments. Postflight the animals developed some reactions that were similar to those in humans. This helps to identify the morphological substrate of certain changes in the human body and to investigate their pathogenesis.     

Preoperative care and anesthesia in surgical treatment of thyrotoxicosis

Light microscopy was used to study the structure and cellular organization of the osphradial organ of the pulmonary mollusque L. stagnalis. The osphradium unites the epithelial canal and the ganglion consisting of two cell populations. On the internal surface of the V-shaped osphradial canal there are three zones of cells: secretory, villous and epithelial. The villous zone of the canal is related with sensory bipolar and multipolar neurons of the ganglion. The irritation percepted by these cells seems to be transferred through numerous zones of neuropile to large unipolar neurons of the ganglion cortical layer.