Psychosocial characteristics of pregnant and nonpregnant HIV-seropositive women

Thirty-three HIV-positive women, 12 of whom were pregnant, participated in semistructured interviews to define areas of psychosocial need. Eighty-eight percent of the subjects reported current unemployment. A history of substance abuse was reported by 82 percent, suicide attempts by 52 percent, and sexual problems by 43 percent. Approximately 30 percent reported elevated levels of depressive symptoms on standardized symptom inventories. The pregnant women appeared psychologically healthier than the nonpregnant group. HIV-positive women face multiple psychosocial stressors and may experience significant psychological distress.     

Assessing obesity: classification and epidemiology

Obesity is generally defined as a body mass index (BMI) of 30 kg/m2 and higher. Overweight is defined as a BMI between 25 and 30 kg/m2. The prevalence varies considerably between countries, and between regions within countries. It is estimated that more than half of adults aged 35-65 living in Europe are either overweight or obese. Overweight is more common among men than among women but obesity is more common among women. The prevalence of obesity in Europe is probably in the order of 10-20% in men and 15-25% in adult women. In most European countries who have reliable data on time-trends the prevalence of obesity seems to be increasing. In most European countries, obesity is usually inversely associated with socio-economic status, particularly among women. New classifications of overweight may be based on cut-off points for simple anthropometric measures which reflects both total adiposity as well as abdominal fatness.     

Carbonization and liquid-crystal (mesophase) development. 12. Mechanisms of the co-carbonization of coals with organic additives

In industrial situations, coals interact with solvents or additives to produce liquid fuels, solvent-refined coal, coal extract and metallurgical coke. In these processes there occurs a wide variation in effects or modifications of the coal by these additives. This paper describes the modifications which can occur, using a wide range of rank of coal, when these coals interact and are co-carbonized with a wide range of additives of different chemical properties. The optical texture of the resultant cokes is given special attention. The objective of the paper is to summarize the current state of knowledge of the mechanisms of these interactions. Possible mechanisms of interactions are summarized, kinetic and chemical structural aspects of reactions are outlined, the importance is mentioned of the formation of liquid phases enabling anisotropic optical textures in modified cokes to be created, and the industrial relevance of its possible development is discussed.     

Carbonization and liquid-crystal (mesophase) development. 8. The co-carbonization of coals with acenaphthylene and decacyclene

Several coals of different rank have been carbonized singly and also co-carbonized with acenaphthylene and decacyclene. The resultant cokes were mounted in resin and polished surfaces were examined for optical texture using a polarized-light optical microscope fitted with a half-wave retarder plate. The optical texture can be assessed qualitatively (visually) or quantitatively by a point-counting technique in terms of size and shape of constituent isochromatic anisotropic units. Some cokes from coals were Isotropic. Acenaphthylene was only able to exert a smaller influence than decacyclene on the optical texture of the resultant cokes from co-carbonizations. Decacyclene was able to modify the optical texture for both the low-rank non-fusible and the caking coals. The effects of changing the proportions of coal to additive were examined. Results are interpreted in terms of ‘depolymerization’ of the coal by the action of the additive (as solvent) and also by the action of the additive in modifying the processes of formation of semi-coke via nematic liquid crystals.     

Carbonization and liquid-crystal (mesophase) development. 7. Optical textures of cokes from acenaphthylene and decacyclene

Optical textures of cokes prepared by carbonizing acenaphthylene, decacyclene and mixtures thereof at selected values of heat-treatment temperatures and soak time have been compared. Optical textures are assessed using polished surfaces and reflected-polarized-light microscopy in conjunction with a half-wave plate. The acenaphthylene is chemically more reactive than the decacyclene which is itself formed during the carbonization of acenaphthylene. Products of carbonization of acenaphthylene can influence rates of carbonization of the decacyclene. Similar optical textures in cokes cannot be formed by compensating low heat-treatment temperatures with long soak periods. In addition to chemical rate-controlling processes, the physical properties of the system must be acknowledged, in particular the viscosity. Very large non-coalesced growth units of mesophase (800 μm diameter) have been observed. Pre-alignment of growth units of mesophase may occur prior to coalescence.     

Hepatectomy with hypothermic perfusion of the liver

Whereas most liver resections can be performed within 60 min, the period of vascular clamping and resulting ischemia may prove too short to allow complex major liver resections (MLR) especially on diseased livers. To overcome this problem, cooling of the liver with 4 degrees C preservations solution routinely used in liver transplantation may be used in three different approaches to MLR: I "In situ": the liver remains in the abdomen and integrity of afferent and efferent vessels is conserved. II "Ex situ-in vivo": the liver exteriorized from the abdomen by transecting all hepatic veins, remains connected to the porta hepatis. III "Ex vivo": the liver being removed from the abdomen, the MLR is performed extracorporeally. Of 15 MLR reported here, 11 were performed "in situ" and 4 "ex situ-in vivo"/Nowadays, the liver surgeon's "toolbox" must contain hypothermic liver perfusion. In carefully selected cases, these techniques allow MLR on diseases livers or mandating complex vascular procedures.     

Structural components in needle-cokes as studied by etching with chromic acid

Structures within commercial calcined needle-cokes are characterized by optical microscopy to reveal optical texture and by scanning electron microscopy before and after etching with chromic acid solution at 400 to 423 K. The needle-cokes exhibit an optical texture of medium and coarse-grained mosaics, acicular flow domains and flow domains. The etching studies indicate that the acicular flow domains are made up of rolled and convoluted lamellae which etch to form laths (needle-like) 3 m across. The mosaics appear when the rolled structures are viewed microscopically sectioned perpendicular to the lamellae. The acicular flow domains appear in longitudinal section. The etching of the flow domains shows that they have a sedimentary structure, 1 to 2 m layer thickness, suggesting that mesophase coalesces within a layer but not between layers. A model is proposed to explain the origin and separation of structures in needle-cokes as created in the delayed coker.     

Transduction properties of tracheal stretch receptors

1. Using single fibre vagal afferent recording, we have studied the behavior of slowly adapting stretch receptors located in an isolated, in situ, segment of the trachea in dogs. Responses to positive and negative steady and oscillating transmural pressures were investigated. 2. Seventy-eight per cent of the receptors studied were tonically active at resting tracheal volume. Ninety per cent showed a more pronounced response to positive than to negative transmural pressures. 3. During pressure oscillations the majority of the receptors had a higher discharge frequency at any given pressure during the ascending phase of the pressure wave than at the same pressure under static conditions. During most of the ensuing descent of pressure toward zero the discharge frequency led transmural pressure. 4. With increasing frequency of oscillation the differences from the static responses increased (dP/dt sensitivity), especially during the ascending limb of the pressure oscillation (rectifying behavior). 5. In a small number of receptors, discharge frequency lagged behind transmural pressure or was in phase with it ("no loop" pattern). 6. In three cases the same receptor exhibited dP/dt sensitivity during positive pressure oscillations, whereas discharge frequency lagged behind pressure during negative pressure oscillations. This indicates that the lack of dP/dt sensitivity exhibited under negative pressure conditions does not represent an intrinsic property of these receptors, but reflects some aspect of their mechanical arrangement within the airway wall. 7. THESE PATTERNS OF RESPONSE ARE DISCUSSed in terms of intrinsic and extrinsic characteristics of the receptors. 8. The physiological implications of stretch receptor behaviour are also considered.     

Broad-area InAs/GaAs quantum dot lasers incorporating intermixed passive waveguide

InAs/GaAs quantum dot lasers incorporating passive waveguide created by post-growth intermixing processing have been studied. Emission wavelength of the passive section shows relative blueshift as high as 135 nm with respect to the emission wavelength of the active section. Intrinsic losses in the section formed by the intermixing are very small. Broad-area lasers with 100 mum stripe width incorporating intermixed section have demonstrated improvements in far-field pattern under both pulsed and continuous wave pumping current