Tentative reference values for some elements in broncho-alveolar lavage fluid.

The concentrations of Fe, Mn, Pb and Cr have been determined in broncho-alveolar lavage (BAL) fluid of 25 subjects without occupational or abnormal environmental exposure to metals, using the AAS method. The numerous factors which can interfere with the results in pre-analytical and in analytical phases are stressed. Metals concentrations in BAL are expressed in micrograms/l. They were not correlated with the volume of fluid recovered, the total cells, alveolar macrophages and erythrocytes. The results were not modified by stratification considering age and sex. Iron concentrations were higher than others, probably due to higher environmental exposure and partly to its essential role in humans. The diagnostic significance of element determination in BAL fluid and the relationship with exposure and lung load is discussed.     

Asymmetries in the preparation and control of manual aiming movements.

Conducted 2 experiments with 20 undergraduates to determine if typical right hand target aiming advantages could be reduced or eliminated by increasing the spatial demands of the aiming task. In Exp 1, right hand advantages were found for both movement time and error regardless of spatial characteristics of the task. When a greater degree of spatial uncertainty was introduced in Exp 2, Ss exhibited a left hand reaction time advantage. Taken together, results suggest that the right cerebral hemisphere may have a special role to play in preparing the spatial aspects of an aiming movement, while the left hemisphere is more important for movement execution. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the complexity of digraph packings

Let be a fixed collection of digraphs. Given a digraph H, a -packing of H is a collection of vertex disjoint subgraphs of H, each isomorphic to a member of . For undirected graphs, Loebl and Poljak have completely characterized the complexity of deciding the existence of a perfect -packing, in the case that consists of two graphs one of which is a single edge on two vertices. We characterize -packing where consists of two digraphs one of which is a single arc on two vertices.     

Photonic devices based on preferential etching

We introduce a design concept of optical waveguides characterized by a practical and reproducible process based on preferential etching of crystalline silicon substrates. Low-loss waveguides, spot-size converters, and power dividers have been obtained with polymers. We have also aligned liquid crystals in the waveguides and demonstrated guided propagation. Therefore this technology is a suitable platform for soft-matter photonics and heterogeneous integration.     

An adaptive friction compensator for global tracking in robot manipulators

A novel adaptive friction compensator based on a dynamic model recently proposed in the literature is presented in this paper. The compensator ensures global position tracking when applied to an n degree of freedom robot manipulator perturbed by friction forces with only measurements of position and velocity, and all the system parameters (robot and friction model) unknown. Instrumental for the solution of the problem is the observation that friction compensation can be recasted as a disturbance rejection problem. The control signal is then designed in two steps, first a classical adaptive robot controller that (strictly) passifies the system, and then a relay-based outer-loop that rejects the disturbance.     

Sternal cleft. Surgical treatment in the newborn

The lack of total sternal fusion without other anomalies of the chest wall is extremely rare. We present the case of one 24 h. old female, clinically asymptomatic with complete sternal cleft without other symptoms. She was operated on within the first week of life, a sternal primary suture with costal condrotomy and alternate costal suture were performed. Good thoracic stability was obtained. We agree with other authors about the need for surgical correction during the neonatal period.     

Preparation and properties of ZnIn2S4 thin films

ZnIn₂S₄ thin films prepared by flash evaporation are polycrystalline and exhibit the structure of ZnIn₂S₄ on X-ray analysis. The films are photoconducting with a dark resistivity of about 10³ ω cm. At low temperatures, when illuminated by gap energy light and subsequently measured in the dark, the films exhibit a residual conductivity which can be removed by heating the samples to room temperature.     

Metabolic perturbation of the inflammatory cells

An activation of the oxidative metabolism of phagocytes is a regular concomitant of phagocytosis as well as of other functions of these cells such as exocytosis, chemotactic locomotion, and immune-adherence. Several other substances, some of which may be found in the inflammatory site, are also able to stimulate the oxidative metabolism of phagocytes, for example phospholipases, antileucocyte antibodies, endotoxins, fatty acids, surfactants and fragments of complement. This paper deals with, (1) the molecular events occurring within the plasma membrane that trigger the stimulation of the oxidative metabolism. An experimental model is presented that involves redistribution of ions across the plasma membrane of leucocytes as the trigger of the stimulated respiration and exocytosis; (2) the intracellular localization of the enzymatic system that is the effector of the metabolic response. A scheme is proposed for the mechanism of this enzymatic system which accounts for the production of highly reactive compounds such as hydrogen peroxide, superoxide anion radical and hydroxyl radical during the metabolic activation of phagocytes.     

Effects of transient carbon deposition on the sodium sulfate-induced corrosion of nickel-base alloys

The role of solid carbon in accelerating the Na₂SO₄-induced corrosion of nickel-base alloys at high temperature has been investigated. Corrosion rates of salt-coated IN 738 alloy in an oxidizing atmosphere containing 0.1 pct SO₂ were much increased when the alloy was initially exposed to a low concentration of methane for a short time at 1273 K (1000°C). Crucible tests carried out with Ni-5 Al, Ni-30 Al, Ni-20Cr-15 Al and IN 738 specimens immersed in Na₂SO₄-carbon mixtures showed that corrosion of these alloys was dramatically enhanced if the carbon persisted long enough to form a Na₂S phase by reaction with the Na₂SO₄. In an oxidizing environment a graphitic carbon had a more pernicious effect on alloy corrosion resistance than a finely dispersed carbon black which burnt away more readily. Corrosion rates in air were also accelerated in the presence of carbonized crude oil residue such as might be formed as a result of incomplete fuel combustion in a gas turbine.