Irritancy testing in occupational dermatology: comparison between two quick tests and the acute irritation induced by sodium lauryl sulphate

OBJECTIVE: To evaluate the efficacy of exploratory vitrectomy for certain traumatized eyes with no light perception (NLP) and dense vitreous hemorrhage. METHOD: We performed vitrectomy on 10 patients with NLP eyes after ocular trauma. Of them, eight had open globe injuries and two had closed blunt ocular trauma. RESULTS: Postoperatively, six had visual acuities of light perception to 0.25 and four remained NLP. In most eyes, a potentially functional posterior retina and optic disc were observed during surgery. CONCLUSION: Dense vitreous hemorrhage could be the most important factor for NLP after severe ocular trauma. Therefore, NLP does not always mean permanent loss of vision. Proper primary repair of the wound and timely vitrectomy may give a chance of visual recovery in selected traumatized eyes.     

Atmospheric and low pressure shadow masked MOVPE growth of InGaAs(P)/InP and (In)GaAs/(Al)GaAs heterostructures and quantum wells

The shadow masked growth technique is presented as a tool to achieve thickness and bandgap variations laterally over the substrate during metalorganic vapor phase epitaxy. Lateral thickness and bandgap variations are very important for the fabrication of photonic integrated circuits, where several passive and active optical components need to be integrated on the same substrate. Several aspects of the shadow masked growth are characterized for InP based materials as well as for GaAs based materials. Thickness reductions are studied as a function of the mask dimensions, the reactor pressure, the orientation of the masked channels and the undercutting of the mask. The thickness reduction is strongly influenced by the mask dimensions and the reactor pressure, while the influence of the orientation of the channels and the amount of undercutting is only significant for narrow mask windows. During shadow masked growth, there are not only thickness variations but also compositional variations. Therefore, we studied the changes in In/Ga and As/P ratios for InGaAs and InGaAsP layers. It appears that mainly the In/Ga-ratio is responsible for compositional changes and that the As/P-ratio remains unchanged during shadow masked growth.     

Whole-body 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) for accurate staging of Hodgkin's disease

BACKGROUND: Staging of Hodgkin's disease (HD) is accomplished by a variety of invasive and non-invasive modalities. This prospective study was undertaken to investigate the value of whole-body positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) in defining regions involved by lymphoma compared with conventional staging methods in patients with HD. PATIENTS AND METHODS: Fourty-four newly diagnosed patients with HD underwent FDG-PET as part of their initial staging work-up. PET findings were correlated with findings of conventional staging including computed tomography, ultrasound, bone scanning, bone marrow biopsy, liver biopsy and laparotomy. When results of FDG-PET differed to those obtained by conventional methods reevaluation was performed by biopsy, if possible, or magnetic resonance imaging. RESULTS: The results of FDG-PET were compared with three hundred twenty-one conventional staging procedures performed in 44 patients. FDG-PET was positive in 38 of 44 (86%) patients at sites of documented disease. PET detected additional lesions in five cases previously not identified by conventional staging methods. In another case a nodal lesion suspect on CT was negative at FDG-PET and was settled as true negative by biopsy. As a consequence of PET findings five patients had to be upstaged and one patient had to be downstaged, resulting in changes in treatment strategy in all six cases (14%). FDG-PET failed to visualize sites of HD in four patients. In two of our patients a false positive PET result was obtained. CONCLUSIONS: Our data indicate that FDG-PET provides an imaging technique that appears to visualize involved lesions in most patients with HD and is useful in the management of these patients.     

Synthesis,Characterization and Application of Sucrose Carboxylic Acid Polyesters — A Prototype of Non-Caloric or Surface Active Compounds

Sucrose carboxylic acid polyesters are in dependence of the degree of acylation and fatty acid composition more or less undigestible or emulsifying fat substitutes and functional additives for foods. In this connection the relationships between their molecular parameters and functional properties are discussed. New procedures of the solvent-free synthesis are presented. Furthermore, open biochemical and toxicological problems of pinocytosis and accumulation of intact polyesters in organs and tissue being still under investigations are considered.     

172 nm excimer VUV-triggered photodegradation and micropatterning of aminosilane films

Emission from Xe₂* excimers exhibiting photon energies between 7 and 10 eV can be used to induce strong surface modification effects on polymeric materials in the top 100 nm layer. In order to identify suitable monomers for this VUV-based process, the photodegradation mechanism of different organosilanes of the general structure R-CH₂-Si(OCH₃)₃ was elucidated by quantum chemical calculations. Herein, the photodegradation of 3-aminopropyltrimethoxysilane films by the use of a 172 nm excimer lamp under different irradiation conditions is described and completed by micropatterning experiments. The presence of 1000-5000 ppm oxygen was found to promote the transformation process to an inorganic-like surface. The films obtained were analyzed by X-ray photoelectron spectroscopy, contact angle measurements and fluorescence microscopy after covalent attachment of a fluorescent dye to the remaining amino groups. Complementary, silver staining was used to visualize photopatterning.     

Morphology and corrosion resistance of Cr(III)-based conversion treatments for electrogalvanized steel

The effectiveness of Cr(VI)-based passivation treatments is well accepted but there are many problems with regard to their environmental suitability. Because these compounds are carcinogenic and toxic, eco-friendly systems capable of replacing them are being evaluated. In this work, the corrosion behavior in 0.5 M NaCl solution of zinc coatings deposited from a free-cyanide alkaline bath and treated with Cr³⁺ based passivation coatings were characterized through DC and EIS techniques. The salt spray test as well as studies of the surface structure and chemical composition were also performed. From these analyses it was inferred that (1) the green-colored Cr³⁺ passivated coatings provide better corrosion resistance than the yellow- and blue-colored coatings, and (2) together with an adequate painting system, they could be a less polluting and less toxic alternative to traditional chromate coatings.     

Die Berechnung der Zündschwingung eines vielstufigen Marxschen Stoßgenerators

Zusammenfassung Unter der Voraussetzung gleichmäßig über den Generator verteilter elektrischer Größen wird der Einschwingvorgang des Generators bei gleichzeitigem Zünden aller Zwischenfunkenstrecken berechnet. Es zeigt sich, daß der idealisierte Generator außer in der Grundwelle mit =4l in einer unendlichen Anzahl von ungeradzahligen höheren Harmonischen schwingt, deren Amplituden jedoch mit wachsender Ordnungszahl sehr rasch abnehmen. Der wirkliche Schwingungsverlauf an einem ausgeführten 15stufigen Stoßgenerator zeigt allerdings gegenüber dem theoretischen Verlauf außer der Grundschwingung eine weitere Oberschwingung, die von zwei räumlich weit ausgedehnten Querrahmen an der 6. und 11. Stufe herrührt, sehr stark ausgeprägt. Vermutlich spielt dabei auch die verspätete Zündung der oberen Zwischenfunkenstrecken eine wesentliche Rolle.Zur restlosen Dämpfung der Oberschwingung ist ein wesentlich größerer Reihenwiderstand im Generator erforderlich, als für die Dämpfung der Grundschwingung ausreichend wäre. Dadurch wird die Stirn der entstehenden Stoßspannungswelle bei großen Generatoren stark verflacht und der Wirkungsfaktor der Anlage bei kurzen Stoßwellen in unerwünschter Weise durch den Spannungsverlust im Dämpfungswiderstand herabgesetzt.     

Skin problems in sugar artists

The antipsoriatic effects of two topical antipsoriatic agents, betamethasone valerate (Betnovate) and calcipotriol (Daivonex), and a pure nanocolloid gel were assessed in 10 patients with chronic plaque-type psoriasis in a modified psoriasis plaque test. Three noninvasive bioengineering methods were applied to measure antipsoriatic effects: chromametry for objective evaluation of erythema; visiometry, a method for profilometry, and 20-MHz skin ultrasound for the measurement of skin thickness as a parameter of inflammatory infiltration and psoriatic hyperproliferation of the epidermis. Regarding inflammation parameters such as skin thickness (infiltration) and erythema (dilatation of vessels and hyperperfusion), the steroid preparation Betnovate proved to be significantly most effective in our study. Daivonex showed significant decreases in the skin roughness parameters, underlining its antiproliferative effect. The nanocolloid carrier was significantly effective in thickness reduction, this effect being most probably due to occlusion. 20-MHz ultrasound, chromametry and visiometry proved to provide multiparameter assessment of treated and untreated psoriatic skin and can be recommended as objective and reproducible measurements for further studies.     

Effects of irrelevant stimulus orientation on visually guided grasping movements.

The present study investigated the effects of irrelevant stimulus orientation on visually guided grasping movements. Participants had to grasp a rectangular object at either the ends or the sides, depending on the color of a visual stimulus. In this task, correspondence between stimulus orientation and object orientation (stimulus-object congruency) and correspondence between stimulus orientation and hand orientation (stimulus-hand congruency) varied independently. Two experiments, with different sets of object orientations, revealed a consistent pattern of results. In particular, there were significant effects of stimulus-hand congruency, suggesting that perceiving an object activates congruently oriented hand movements. However, stimulus-object congruency had no effects, indicating that participants did not benefit from a preactivation of object orientation in the present task. The pattern of congruency effects implies that the cognitive representation, which is affected by irrelevant visual information, entails only those object or response features that are needed to select and control a response. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Essential functional role of the polysaccharide intercellular adhesin of Staphylococcus epidermidis in hemagglutination

Hemagglutination of erythrocytes is a common property of Staphylococcus epidermidis strains, which is related to adherence and biofilm formation and may be essential for the pathogenesis of biomaterial-associated infections caused by S. epidermidis. In three independent biofilm-producing, hemagglutination-positive S. epidermidis isolates, interruption of the icaADBC operon essential for polysaccharide intercellular adhesin (PIA) synthesis by Tn917 insertions led to a hemagglutination-negative phenotype. An immunoglobulin G fraction of antiserum to PIA greatly reduced hemagglutination. Purified PIA led to a 64-fold decrease of hemagglutination titers of these strains; however, it did not mediate hemagglutination by itself. These observations define PIA as the hemagglutinin of S. epidermidis or at least as its major functional component.