Optical Properties of GaAs Quantum Dots Fabricated by Filling of Self-Assembled Nanoholes.

Experimental results of the local droplet etching technique for the self-assembled formation of nanoholes and quantum rings on semiconductor surfaces are discussed. Dependent on the sample design and the process parameters, filling of nanoholes in AlGaAs generates strain-free GaAs quantum dots with either broadband optical emission or sharp photoluminescence (PL) lines. Broadband emission is found for samples with completely filled flat holes, which have a very broad depth distribution. On the other hand, partly filling of deep holes yield highly uniform quantum dots with very sharp PL lines.

Cobertura de exposição de tela de marlex® pós reconstrução de parede abdominal: relato de três casos e revisão de literatura / Coverage of marlex® mesh extrusion after post-abdominal wall reconstruction: 03 case reports and review of the literatura

O uso de telas de material aloplástico na cirurgia de reconstrução da parede abdominal é freqüente em casos de trauma, infecção, ressecção de tumores ou até mesmo em necroses por radioterapia2,3,4,5,10,11. Apesar dessa técnica de cobertura ser de uso comum e rotineiro, em alguns casos, uma complicação é a sua exposição 2,5,6,7,8. Os retalhos são utilizados para proporcionar uma cobertura estável da tela exposta 2,3,5,8,9,11,14. Objetivos: esse trabalho descreve 03 casos de cobertura com retalho a ascio cutâneo de exposição de tela de polipropileno(Marlex ®), utilizada em situação da reconstrução de parede abdominal. Métodos: três pacientes foram submetidos à cirurgia parare construção da parede abdominal, em 20006, utilizando-se tela de polipropileno (Marlex ®). Todos evoluíram com exposição da tela. Dois eram do sexo masculino e um, do sexo feminino. No grupo masculino, um dos pacientes havia sido submetido à apendicectomia e evoluiu com fasceíte necrotizante. O outro paciente masculino teve reconstrução de parede abdominal decorrente de complicação de cirurgia para resolução de quadro de oclusão intestinal. A paciente do sexo feminino foi submetida à reconstrução da parede abdominal após peritoneostomia secundária à perfuração iatrogênica de intestino, decorrente de cirurgia ginecológica. Resultados: Os dois pacientes masculinos foram submetidos à cobertura da tela de Marlex® exposta, utilizando-seretalho inguinal, sendo que, em um dos casos, houve realização de retalho em um único tempo cirúrgico. No outro, houve reconstrução cirúrgica em dois tempos. A paciente feminina foi submetida à cirurgia com realização de retalho fasciocutâneo tipo abdominoplastia, em tempo cirúrgico único. Todos os três casos evoluíram bem, sem complicações pós-operatórias, tais como infecção ou necrose.

Background: posthetic mesh are used in abdominal wall reconstruction1,11 due to trauma, infection, tumor resection or even radiation necrosis2,3,4,5,10,11. Although this kind of coverage is widely used, exposure of the material used is a complication that is unlikely to happen2,5,6,7,8. Fasciouscutaneous flaps are used to provide a stable coverage of the exposed mesh2,3,5,8,9,11,14. Objective: thisworkdescribestree 3 casesofmes hexposure after abdominal wall reconstruction treated coverage using fasciouscutaneous flap and reviews the literature. Methods: Three patients undergone abdominal wall reconstruction in 2006 using polypropylene mesh (Marlex ®).All of them developed mesh exposure. Two were men and one was a woman. One of the men was submitted to appendicectomy and evoluated with necrotizing fasciitis; the second male patient suffered from bowel occlusion and the female pacient, was submitted to reconstruction after peritoneostomy due to iatrogenic bowel perforation duing a gynecologic procedure. Results: the two male patientsweresubmittedtomeshexposurecoverageusing inguinal flap. One of them was submitted to a one-step surgical act. The second male patient needed a two-step surgical act. The female patient was submitted to reconstruction using a one-step abdominoplasty flap. All of them evoluated well, with no post-surgical complications as infection or flap necrosis. Conclusions: although there are no statistical significancies in the three cases, we can say that fasciocutaneous flaps2,12,14 are a securemethodforcoverageofmeshexposureinprevious abdominal wall reconstruction.

Relative bioavailability of imipramine (Tofranil) coated tablets in healthy volunteers.

OBJECTIVES: Imipramine is a tricyclic antidepressant drug with a considerable hepatic first-pass metabolism resulting in highly variable pharmacokinetic characteristics and desipramine as active major metabolite. This study describes the bioavailability of 3 formulations of imipramine. METHODS: In a randomized, three-period crossover study, 18 healthy male Caucasian subjects received single oral doses of Tofranil 25, Tofranil mite (10 mg) and an aqueous solution containing 25 mg imipramine-HCl. Serum concentrations of imipramine-HCl and its main metabolite desipramine were measured. The pharmacokinetic characteristics, Cmax, AUC, t1/2 and tmax were determined and the relative bioavailability of the two coated tablet formulations was calculated with the aqueous solution as reference. Safety and tolerability were assessed using vital signs, ECG, clinical laboratory and adverse event recording. RESULTS: The relative bioavailabilities of Tofranil 25 and Tofranil mite were 97% and 81%, respectively. The study medication was well tolerated. CONCLUSIONS: A sufficiently high extent of absorption was found for the test formulations ensuring therapeutic efficacy.

Treatment of acute ischemic stroke with the low-molecular-weight heparin certoparin: results of the TOPAS trial. Therapy of Patients With Acute Stroke (TOPAS) Investigators.

BACKGROUND AND PURPOSE: To study the safety and efficacy of the low-molecular-weight heparin certoparin, we performed a randomized, double-blind, dose-finding multicenter trial in patients with acute ischemic stroke (Therapy of Patients With Acute Stroke [TOPAS]). METHODS: We randomized 404 patients to 4 treatment groups within 12 hours of stroke onset: 3000 U anti-factor Xa (aXa) certoparin once daily (treatment group 1); 3000 U aXa twice daily (group 2); 5000 U aXa twice daily (group 3); and 8000 U aXa twice daily (group 4). The primary efficacy variable was the proportion of patients reaching a favorable functional outcome (Barthel Index >/=90 points) at 3 months. CT was performed at trial entry, after 7 days, and on clinical deterioration. RESULTS: The proportion of patients with Barthel Index >/=90 was not different between treatment arms (61.5%, 60.8%, 63.3%, and 56.3% in the 4 groups, respectively; intent-to-treat population). European Stroke Scale scores improved in all treatment groups within the first 14 days to a similar extent. During the follow-up of 6 months, percentages of patients with recurrent stroke/transient ischemic attack were 11.0%, 5.9%, 9.7%, and 13.0% in the 4 groups, respectively. Overall mortality was only 7.4%. Two parenchymal cerebral hematomas and 1 extracranial bleeding episode occurred in treatment group 1 versus 1 and 0 in group 2, 2 and 0 in group 3, and 4 and 5 in group 4, respectively. During certoparin treatment, 1 deep vein thrombosis but no pulmonary embolism was observed. CONCLUSIONS: Dose increase of certoparin up to 8000 U aXa twice daily did not improve the functional outcome of patients with ischemic stroke. Severe bleeding tended to be more frequent in the highest dose group only.

Interface-mediated death of unconditioned Tetrahymena cells: effect of the medium composition.

We have previously shown that the cell death of Tetrahymena thermophila in low inocula cultures in a chemically-defined medium is not apoptotic. The death is caused by a cell lysis occurring at the medium-air interface and can be prevented by the addition of insulin or Pluronic F-68. Here, we report that cell death can also be caused by the medium. The specific effects of several medium constituents were tested in the presence and absence of an interface. Four of the 19 amino acids (arginine, aspartic acid, glutamic acid, and histidine in millimolar concentration) as well as Ca2+ (68 microM) and Mg2+ (2 mM) and trace metal ions (micromolar concentrations) are all sufficient to induce the interface-mediated death. The effect of the amino acids and the salt ions Ca2+ and Mg2+ can be abolished by the addition of insulin (10(-6) M) or Pluronic F-68 (0.01% w/v), whereas insulin/Pluronic F-68 only postpones the death induced by trace metal ions. On the basis of our findings, a new recipe for a chemically-defined medium has been formulated. Single cells can grow in this medium in the presence of medium-air interface without any supplements.

Placebo-controlled comparison of the efficacy and tolerability of once-daily moxonidine and enalapril in mild-to-moderate essential hypertension.

OBJECTIVES: To compare the antihypertensive efficacy and tolerability of the imidazoline I1 receptor agonist moxonidine, a centrally acting antihypertensive, with the angiotensin converting enzyme inhibitor enalapril. DESIGN: An 8-week, double-blind, randomized, placebo-controlled study involving 140 outpatients with mild-to-moderate essential hypertension. METHODS: Outpatients with WHO stage I or II hypertension were enrolled in the study. After a 4-week placebo-controlled stabilization phase patients were allocated randomly to placebo, 0.2 mg moxonidine once a day or 5 mg enalapril once a day for 2 weeks. Dosages were then doubled to 0.4 mg moxonidine once a day or 10 mg enalapril once a day for a further 6 weeks. Blood pressure responses to therapy were measured by conventional office techniques and by 24 h ambulatory blood pressure monitoring. RESULTS: The mean reduction in sitting blood pressure with moxonidine was similar to that with enalapril (19.5 +/- 16.0/12.3 +/- 8.7 versus 18.9 +/- 13.7/11.8 +/- 8.0 mmHg) and significantly superior to that with placebo (-4.6 +/- 12.3/-4.7 +/- 6.8 mmHg, P< 0.001). In addition to reducing blood pressure during conventional measurements, moxonidine administration reduced blood pressure throughout 24 h ambulatory measurements. The trough:peak ratio for moxonidine was 0.7. Both moxonidine and enalapril were tolerated well. CONCLUSIONS: Moxonidine is an effective and well-tolerated antihypertensive, at least as good as other established forms of antihypertensive medication. The trough:peak ratio of 0.7 indicates that the drug will be effective administered once a day.

Surface mediated death of unconditioned Tetrahymena cells: effect of physical parameters, growth factors, hormones, and surfactants.

A new form of cell death has been observed. The death occurs at liquid-air interfaces when Tetrahymena cells are grown in a chemically defined medium (CDM) at low inocula. The cells die by lysis at the liquid-air interface (medium surface), which they reach due to negative gravitaxis as well as positive aerotaxis. When the cells are grown in a closed compartment, with no liquid-air interface, the death is not observed, and the cells proliferate. Cloning of cells in CDM is thus possible. The addition of effectors such as NGF (10(-11) M), EGF (10(-10) M), PDGF (10(-10) M), and insulin (10(-7) M) to cells in CDM prevents the surface mediated death. Since detergents/surfactants like SDS (7 x 10(-5) M), NP-40 (2 x 10(-5) M), Tween 80 (10(-4))% w/v), Pluronic F-68 (10(-7) M), and the biosurfactant surfactin (10(-6) M) have the same effect, we suggest that the effectors act by stimulating the cells to exudate surfactant(s) of their own. Furthermore, lyzed cells and exudates from living cells (pre-conditioned medium) prevent the death. In conditions with liquid-air interfaces, certain physical parameters are of great importance for the survival of cells at low inocula. The parameters are the distance to the surface, the temperature, and the inoculum. By increasing the height of the medium, lowering the temperature, and increasing the inoculum of the culture, the survival can be greatly enhanced. There is no evidence for programmed cell death (PCD) or apoptosis.