422 research outputs found
Transurethral resection and surveillance of bladder cancer supported by 5-aminolevulinic acid-induced fluorescence endoscopy
Purpose: We determined whether neoplastic disease, which was missed under white light can be found during transurethral resection of bladder cancer by 5-aminolevulinic acid-induced porphyrin fluorescence. Materials and Methods: 5-Aminolevulinic acid-induced fluorescence endoscopy was carried out in 328 cases. A 3% 5-aminolevulinic acid solution was instilled intravesically in a mean time of 2.8 h before endoscopy, The fluorescence was excited by a special incoherent light source which provided blue light in addition to white light. Results: In 82 (25%) cases additional neoplastic lesions were found only because of their red porphyrin fluorescence which was induced by 5-aminolevulinic acid. 31% of these neoplastic foci which were found in normal and nonspecific inflamed mucosa had a poorly differentiated histology. Conclusions: 5-Aminolevulinjc acid facilitates detection of neoplastic disease during transurethral resection of bladder cancer and increases the accuracy of diagnosis
Espace(s) public(s), une esquisse
NĂ©gligĂ© pendant plusieurs dĂ©cennies, lâespace public se retrouve aujourdâhui au centre des dĂ©bats. Touchant des acteurs de plus en plus nombreux, il suscite les attentes les plus diverses. Souvent idĂ©alisĂ© dans son archĂ©type historique, lâespace public peine Ă trouver sa place dans lâexpansion difficilement maĂźtrisable de lâenvironnement urbain contemporain. Comment cerner la notion dâespace public pĂ©riurbain dans les agglomĂ©rations contemporaines ? Dans quelle mesure les politiques publiques peuvent-elles conditionner la production urbaine ? De quelle maniĂšre la problĂ©matique des espaces publics sâinscrit-elle dans la logique du dĂ©veloppement urbain durable ? Lâespace public prend des sens diffĂ©rents selon les approches possibles : que lâon y pĂ©nĂštre depuis les domaines de lâurbanisme, de la sociologie, de lâarchitecture, du design, des sciences sociales et politiques, la perception en sera diffĂ©rente. Cependant, cet espace ne se laisse pas aisĂ©ment dissĂ©quer. Ses significations symboliques comme ses usages concrets sâinterpĂ©nĂštrent et se mĂȘlent inextricablement. Mais lâespace public durable est plus vaste : pris sous lâangle du corpus du dĂ©veloppement urbain durable, il intĂšgre ses trois thĂšmes triangulaires, et met en perspective le rĂŽle quâil joue dans les mutations urbaines des pĂ©riphĂ©ries
Photodynamic therapy of prostate cancer by means of 5-aminolevulinic acid-induced protoporphyrin IX - In vivo experiments on the dunning rat tumor model
Objective: In order to expand the use of photodynamic therapy (PDT) in the treatment of prostate carcinoma (PCA), the aim of this study was to evaluate PDT by means of 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX ( PPIX) in an in vivo tumor model. Methods: The model used was the Dunning R3327 tumor. First of all, the pharmacokinetics and the localization of PPIX were obtained using fluorescence measurement techniques. Thereafter, PDT using 150 mg 5-ALA/kg b.w.i.v. was performed by homogenous irradiation of the photosensitized tumor (diode laser lambda = 633 nm). The tumors necrosis was determined histopathologically. Results: The kinetics of PPIX fluorescence revealed a maximum intensity in the tumor tissue within 3 and 4.5 h post-application of 5-ALA. At this time, specific PPIX fluorescence could be localized selectively in the tumor cells. The PDT-induced necrosis (n = 18) was determined to be 94 B 12% (range 60-100%), while the necrosis of the controls ( n = 12) differs significantly (p < 0.01), being less than 10%. Conclusion: These first in vivo results demonstrate the effective potential of 5-ALA-mediated PDT on PCA in an animal model. Copyright (C) 2004 S. Karger AG, Basel
Cuff overinflation and endotracheal tube obstruction: case report and experimental study
Background: Initiated by a clinical case of critical endotracheal tube (ETT) obstruction, we aimed to determine factors that potentially contribute to the development of endotracheal tube obstruction by its inflated cuff. Prehospital climate and storage conditions were simulated. Methods: Five different disposable ETTs (6.0, 7.0, and 8.0 mm inner diameter) were exposed to ambient outside temperature for 13 months. In addition, every second of these tubes was mechanically stressed by clamping its cuffed end between the covers of a metal emergency case for 10 min. Then, all tubes were heated up to normal body temperature, placed within the cock of a syringe, followed by stepwise inflation of their cuffs to pressures of 3 kPa and >=12 kPa, respectively. The inner lumen of the ETT was checked with the naked eye for any obstruction caused by the external cuff pressure. Results: Neither in tubes that were exposed to ambient temperature (range: -12°C to +44°C) nor in those that were also clamped, visible obstruction by inflated cuffs was detected at any of the two cuff pressure levels. Conclusions: We could not demonstrate a critical obstruction of an ETT by its inflated cuff, neither when the cuff was over-inflated to a pressure of 12 kPa or higher, nor in ETTs that had been exposed to unfavorable storage conditions and significant mechanical stress
Compound-specific isotope analysis of benzotriazole and its derivatives
Compound-specific isotope analysis (CSIA) is an important tool for the identification of contaminant sources and transformation pathways, but it is rarely applied to emerging aquatic micropollutants owing to a series of instrumental challenges. Using four different benzotriazole corrosion inhibitors and its derivatives as examples, we obtained evidence that formation of organometallic complexes of benzotriazoles with parts of the instrumentation impedes isotope analysis. Therefore, we propose two strategies for accurate C and N measurements of polar organic micropollutants by gas chromatography isotope ratio mass spectrometry (GC/IRMS). Our first approach avoids metallic components and uses a Ni/Pt reactor for benzotriazole combustion while the second is based on the coupling of online methylation to the established GC/IRMS setup. Method detection limits for on-column injection of benzotriazole, as well as its 1-CH -, 4-CH -, and 5-CH -substituted species were 0.1-0.3mM and 0.1-1.0mM for ÎŽ13C and ÎŽ15N analysis respectively, corresponding to injected masses of 0.7-1.8 nmol C and 0.4-3.0 nmol N, respectively. The Ni/Pt reactor showed good precision and was very long-lived ( 1000 successful measurements). Coupling isotopic analysis to offline solid-phase extraction enabled benzotriazole-CSIA in tap water, wastewater treatment effluent, activated sludge, and in commercial dishwashing products. A comparison of C and N values from different benzotriazoles and benzotriazole derivatives, both from commercial standards and in dishwashing detergents, reveals the potential application of the proposed method for source apportionmen
Analysis of Different Models of Iron Precipitation in Multicrystalline Silicon
Simulation of solar cell processing enables inexpensive and rapid process optimization. Over the last twenty years, several models describing the distribution and behavior of iron point defects and iron-silicide precipitates have been developed and incorporated into process simulations. The goal of this work is to elucidate what physics are needed to accurately describe industry-relevant as-grown impurity and defect distributions and processing conditions by simulating different material-processing combinations with each model. This rigorous comparison helps scientists and engineers choose the appropriate level of model complexity, and consequently simulation run time, based on material characteristics and processing conditions.Peer reviewe
Electric Field Controlled Magnetic Anisotropy in a Single Molecule
We have measured quantum transport through an individual Fe
single-molecule magnet embedded in a three-terminal device geometry. The
characteristic zero-field splittings of adjacent charge states and their
magnetic field evolution are observed in inelastic tunneling spectroscopy. We
demonstrate that the molecule retains its magnetic properties, and moreover,
that the magnetic anisotropy is significantly enhanced by reversible electron
addition / subtraction controlled with the gate voltage. Single-molecule
magnetism can thus be electrically controlled
Keeping up with dynamics of next generation missiles
ABSTRACT In an effort to comply with the increasing quest for higher dynamics and increased inertia of test units modern HWILsystems are employing increasingly larger hydraulic actuators. A new 3-axis flight motion simulator with increased performance is reviewed. Also future trends of the HWIL-systems are discussed both for hydraulic and electric actuators. Some drawbacks of hydraulic systems, including increased acoustic noise levels and extensive service and maintenance requirements from the hydraulic power unit, limited stroke of the actuators for large systems and poor small signal performance are discussed and compared to the performance of electric actuators. Can the electric actuators advantages make up for the power density performance gap
Kondo screening in d-wave superconductors in a Zeeman field and implications for STM spectra of Zn-doped cuprates
We consider the screening of an impurity moment in a d-wave superconductor
under the influence of a Zeeman magnetic field. Using the Numerical
Renormalization Group technique, we investigate the resulting pseudogap Kondo
problem, in particular the field-induced crossover behavior in the vicinity of
the zero-field boundary quantum phase transition. The impurity spectral
function and the resulting changes in the local host density of states are
calculated, giving specific predictions for high-field STM measurements on
impurity-doped cuprates.Comment: 5 pages, 4 figs, (v2) remark on c-axis field added, discussion
extended, (v3) final version as publishe
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