Slow passage through thresholds in quantum dot lasers.

A turn on of a quantum dot (QD) semiconductor laser simultaneously operating at the ground state (GS) and excited state (ES) is investigated both experimentally and theoretically. We find experimentally that the slow passage through the two successive laser thresholds may lead to significant delays in the GS and ES turn ons. The difference between the turn-on times is measured as a function of the pump rate of change ɛ and reveals no clear power law. This has motivated a detailed analysis of rate equations appropriate for two-state lasing QD lasers. We find that the effective time of the GS turn on follows an ɛ^{-1/2} power law provided that the rate of change is not too small. The effective time of the ES transition follows an ɛ^{-1} power law, but its first order correction in ln(ɛ) is numerically significant. The two turn ons result from different physical mechanisms. The delay of the GS transition strongly depends on the slow growth of the dot population, whereas the ES transition only depends on the time needed to leave a repellent steady state.

[The microcirculatory bed of the cerebral dura mater in normal infants during the 1st year of life and in elevated intracranial pressure]. / Mikrotsirkuliatornoe ruslo tverdoi obolochki golovnogo mozga detei 1-go goda zhizhni v norme i pri povyshenii vnutricherepnogo davleniia.

Microcirculatory vascular bed was sampled from dura mater of children under 1 year (healthy and with intracranial hypertension due to innate hydrocephalus) and stained with hematoxylin-eosin. Micro- and macroscopy of the modular organization of microvasculature showed that the rise in intracranial pressure resulted in restructuring of the arteriolar bed, appearance of unusual vascular forms, volume expansion and changes in other parameters, especially in the inner layer of dura mater. Capillary network was also distorted.

[Variability of the gyri and sulci of the temporal lobe of human brain]. / K variabel'nosti izvilin i borozd visochnoi doli mozga cheloveka.

A study was made of the relief of the temporal lobes from 204 hemispheres of human brain. The authors examined and compared the typological features of the structure of these lobes gyrus. Established the regularities of the construction of temporal gyrus in both hemispheres together with their complexity and diversity, interhemispheric and intertypic asymmetry. Showed variability and complexity of the typological signs to be most pronounced in the areas of the temporal lobe connected with the acoustic center of speech.

[Clinico-morphologic aspects of the active skin points of the upper extremities and their importance in reflexotherapy]. / Kliniko-morfologicheskie aspekty aktivnykh tochek kozhi verkhnei konechnosti cheloveka i znachenie ikh dlia refleksoterapii.

Using an acoustic apparatus designed by G. N. Novinsky the authors studied the morphological structure of the skin in the area of active points on the arm. The authors also used micro-macroscopic preparation after V. P. Vorobiev with the subsequent histological investigation of the sites where these points were distributed. There was a considerable amount of friable connective tissue in the area of the active points which was distributed in the form of meshwork in some areas. The data obtained make it possible to specify the topography of the distribution of active points which is of great practical value for improving the efficacy of acupuncture.

[Morphofunctional characteristics of the ovaries, thyroid gland and adrenal glands in experimental lead acetate poisoning]. / Morfofunktsional'naia kharakteristika iaichnikov, shchitovidnoi zhelezy i nadpochechnikov pri éksperimental'nom otravlenii uksusnokislym svintsom.

Daily doses of 50 mg/kg of lead acetate injected into the laboratory animals induce morphologic changes in the parenchyma of ovaries, thyroid gland, adrenals and compromises neural mediating processes in paraventricular and supraoptic nuclei of hypothalamus. The observed morphologic changes are similar to those characteristic for intensive functioning. Prolonged exposure to lead acetate (daily dose 10 mg/kg) results in adaptation and compensation, which preserves the functional potential of the organs. The morphologic changes in the endocrine organs do not lead to significant hormonal changes.

Development of reflexogenic zone innervation of the human cardiovascular system.

The development of the innervation of the human branchial aortic arches and the heart has been investigated. The early growth of nerve fibres to the 1st, 2nd, 3rd, 4th and 6th aortic arches has been established. Evidence of the transformation of the 1st and 2nd aortic arches and the 4th right one into highly sensitive zones is presented. The order in which nerve connections of the arch regions which develop into reflexogenic zones in a definitive organism are formed is demonstrated. The cranial nerve fibres grow first, and are followed by the sympathetic trunk fibers. Investigations carried out on the extensive material corroborate Koch's hypothesis (1931) that all aortic arches of the embryo develop into reflexogenic zones.

[Blood aggregation and the system of microcirculation in experimental atherosclerosis, its spontaneous regression and hemosorption]. / Agregatnoe sostoianie krovi i sistema mikrotsirkuliatsii pri éksperimental'nom ateroskleroze, ego spontannoi regressii i gemosorbtsii.

Blood aggregate state and microcirculation were studied during development and spontaneous regression of experimental atherosclerosis and following hemosorption. It has been shown that experimental atherosclerosis is not only accompanied by changes in blood lipid composition, but also by disturbances in the structure and function of microcirculatory bed. Normalization of blood lipid composition and recovery of blood aggregate state and microcirculatory bed structure and function were not observed during spontaneous regression. Repeated hemosorption enhances atherosclerosis regression, normalizes lipid composition of blood and biological membranes and promotes the recovery of microcirculation.

[Reinnervation of internal organs and vessels by the neuropexy technic]. / Reinnervatsiia vnutrennikh organov i sosudov metodom neiropeksii.

Some new data on reinnervation of organs and vessels by means of transplantation of vegetative ganglia and sewing of neural branches are presented. When transplanting the cranial cervical ganglion to a muscle, and the caudal mesenteric ganglion to the urinary bladder wall, some neurocytes in the periphery of the ganglia are preserved; simultaneously, massive outgrowth of neural fibres occurs in the area of transplantation. These facts are considered as formation of a new local innervation center of the organ "recipient". The central part of the dog hypogastric nerve is sewed to the renal artery, in other experiments it is sewed into the rectum wall. A massive regeration of neural fibres along the course of the renal artery and the appearance of a neural ganglion in the rectum wall are stated. The sewed hypogastric nerve grows thicker, especially under the conditions of increased functioning of the organ "recipient". In a number of experiments, the large otic nerve is sewed to the common carotid artery. The development of a young connective tissue growing into the adventitia of the vessel is noted. Numerous regenerating neural fibres surrounding the vessel are noted in this tissue. Thus, a possibility of creating new or supplementary innervating connections of internal organs and vessels by means of sewing to them sensitive nerves or vegetative ganglia is morphologically substantiated.

[Functional morphology of neural elements in interorganic adhesions and in coalesced organs]. / Funktsional'naia morfologiia nervnykh élementov mezhorgannykh srashchenii i srashchennykh organov.

The results of investigations concerning the problem on reinnervation of organs and vessels are summarized. Under the conditions of organo- and neuropexy, regenerating neural fibers pass through two stages of development. The first stage--formation and growth of neural fibers, the second--a more prolonged period of successive quantitative and qualitative morpho-functional transformations of these elements into mature structures. Judging from the histochemical characteristics, the latter become functionally competent by the 5th month after implantation of neural trunks into the arterial walls (the common, carotid and femoral arteries). The organopexies affect the neural cells structure in the denervated urinary organs. The reparative processes occurring, to some extent, protect them from destruction and stimulate their partial restoration. When the vegetative ganglia (the cranial cervical, caudal mesenteric ganglia) are transposed on the organs, some neurocytes are preserved. Their composition and histochemical structure correspond to an intact ganglion. A suggestion is made that the partly preserved ganglion could be used to form a new center of local regulation. An observation has been made according to which under the inductive effect of the donor-organ in the organ-recipient numerous newly formed neural fibers appear. They are capable to participate in reinnervation of the injured organ and, hence, in restoration of its function.