Transplantation of fetal tissues in otorhinolaryngology: current status and prospects for the future

The Welfare of Sick Children in Hospital' was the formal title of a report published in Britain in 1959 which came to be known as the Platt Report, after Sir Harry Platt, the chairman of the parliamentary committee which investigated the care of children in hospital. The committee found the hospitals were miserable places for children, where they were expected to conform to ward routines, not allowed to play; where to lie quietly was the accepted norm, and where, under no circumstances, were the parents allowed to visit outside the declared visiting hours. Subsequent to the publication of the Platt Report a revolution occurred in children's hospitals in Britain and other western countries, including Australia. This paper explores these changes, and discusses implications for paediatric care in hospitals and paediatric nursing education today.     

Automation of on-site observations of chemical suffosion in the foundations of hydraulic structures

Conclusions 1. A method for the real-time determination of water mineralization by means of ion-selective electrodes has been implemented in practical laboratory investigations of chemical suffosion. 2. An analysis of the results of investigations has demonstrated the conceptual feasibility of using calcium ionselective electrodes to significant advantage in automated on-site observations of chemical suffosion in the foundations of head structures situated on gypsiferous and carbonate soils. Translated from Gidroteknicheskoe Stroitel’stvo, No. 7, pp. 26–28, July, 2000.     

The variation of thermoelastic properties under conditions of variation of isotopic composition of diamond

The parameters of interatomic interaction in diamonds of ¹²C and ¹³C isotopes are determined. The parameters are determined by two methods, namely, from the elastic modulus (potential no. 1) and from the sublimation energy at T = 0 K (potential no. 2). Based on these parameters, the Debye model is used to calculate the isobaric temperature dependences of the thermoelastic properties for isotopically different diamonds, namely, the coefficient of thermal expansion (CTE), the density, the elastic modulus B _T , and the specific heat capacity. It is demonstrated that the best agreement with the experimentally obtained dependences of the foregoing parameters is obtained when potential no. 1 is used in calculations. The values of CTE, density, and heat capacity increase in the case of transition from ¹²C diamond to ¹³C diamond. It is demonstrated that the inequality B _T (¹²C) < B _T (¹³C) is valid at T = 0 K, which is associated with the reduction of interatomic spacing in the case of transition from ¹²C diamond to ¹³C diamond. However, as the temperature increases, the volumetric isotopic effect in diamond decreases. It is found that the B _T (T) dependences for ¹²C and ¹³C diamonds intersect at a temperature below the Debye temperature. Therefore, at high temperatures, the elastic modulus for light-isotope diamond comes to exceed that for heavy-isotope diamond, B _T (¹²C) > B _T (¹³C). Experimental results are given which confirm this effect. The variation of the properties of isotopically different diamonds with increasing pressure is discussed.     

Parameters of vacancies’ formation in the carbon-subgroup crystals

The parameters of formation of vacancies in crystals of elements of the carbon subgroup (C_diam, Si, Ge, α-Sn, Pb) are calculated. The method used takes into account both quantum effects at low temperatures and delocalization of atoms at higher temperatures. It is shown that consideration of atom delocalization brings about an increase in the values of enthalpy and entropy and the volume of the vacancy formation. At low temperatures, the parameters of vacancy formation depend heavily on temperature, with the entropy of vacancy formation becoming negative. In the region of high temperatures, good agreement was obtained with both experimental data and theoretical estimates reported in other publications. The dependence of vacancy-related parameters on temperature in the course of isobaric heating of diamond in the range from 100 to 4500 K is studied. The limits of applicability of the Arrhenius equation with temperature-independent energy of activation process are discussed. It is shown that there is validity of the “compensation rule” (correlation between the entropy and enthalpy of vacancy formation) and of the correlation between the volume and entropy of the vacancy formation within the entire studied temperature range.     

On self-diffusion in iron at very strong compression of crystal

The dependences of the parameters of the formation of vacancies and self-diffusion have been calculated as functions of the degree of compression of iron crystals along isotherms of 300 and 3000 K. It has been shown that, in the range of 1 > V/V ₀ > (V/V ₀)_min, the suppression of the activation processes occurs upon isothermal compression and, upon isochoric heating, they are strengthened. Here, V/V ₀ is the ratio of the molar volume of the crystal at a pressure P and temperature T to that at P = 0 and T = 0. However, at V/V ₀ = (V/V ₀)_min = 0.0548, the probability of the formation of vacancies and the self-diffusion coefficient become minimum and, in the course of the further isothermal compression, the strengthening of activation processes occurs, and the activation parameters cease to depend on temperature. It is indicated that this is due to the quantum subbarrier tunneling of atoms over the volume of the crystal. It has been shown that, at V/V ₀ < (V/V ₀)_fr, the surface energy is negative, which should stimulate the process of the fragmentation of the crystal and that (V/V ₀)_fr > (V/V ₀)_min. The isothermal dependence of pressure in bcc iron has been estimated upon its compression to V/V ₀ = 0.001. Based on the calculated isotherms, the magnitudes of pressure at characteristic points of pressure dependences of the parameters of self-diffusion and surface energy have been estimated.     

Analysis of the Thermal Conductivity of Hydrocarbons and Their Derivatives at High Pressures and Temperatures

Calculated values of the thermal conductivity of liquid hydrocarbons at high temperatures and pressures up to 500 MPa are given. The calculated values of thermal conductivity are compared with the experimental data of various authors. It is demonstrated that, at pressures up to 500 MPa, the calculated values of the thermal conductivity agree with the experimental data within 3%.     

On a change in the sign of the entropy of vacancy formation in a crystal

The entropy of vacancy formation (s _v) in a crystal increases with the temperature and, at a certain critical temperature, changes its sign from negative to positive. Physical reasons for this change are considered and a condition under which s _v is positive is established. During the melting of metals, s _v is positive and the appearance of vacancies leads to disordering of the crystal, rendering it less stable and facilitating the formation of new vacancies.     

Electrical properties of semiconductor CdS studied by adsorption spectroscopy

The electrical conductivity of semiconductor CdS films (d ≤ 1 μm) having (0001)S and (0001)Cd polar faces has been measured as a function of temperature at different degrees of adsorption of O₂, NO₂, and N₂O molecules. Adsorption spectroscopy has been used to identify bulk and surface electronic centers in a series of states with a wide range of ionization energies: E _t = 0.14–2.21 eV. In contrast to the bulk centers, which have a quasi-continuous energy spectrum characteristic of CdS, the surface adsorption electronic centers have a discrete energy spectrum. The ionization energy of the electronic centers of adsorption origin in CdS + O₂, CdS + NO₂, and CdS + N₂O structures has been measured for the first time at both polarities of the CdS faces and has been shown to depend on the chemistry of the adsorbate and the polarity of the film face.     

Architectonics of the superficial lymphatic net of the lungs of humans and several representatives of artiodactyl animals

The superficial lymphatic vessels of the lungs were studied in man and some artiodactyl animals by the method of interstitial injection followed by dissection and clearing of the preparations. The superficial lymphatic network of the lungs was established to reside under the visceral pleura and to consist of one layer of capillaries. The lymphatic network consisting of large loops was found in sites with the increased respiratory function and with large pulmonary lobules i.e. on the costal and diaphragm surface of the lungs. In the sites of connection of lymph capillaries there are dilatations--lacunas.