2,675 research outputs found
Kinetics of 5-aminolevulinic acid-induced fluorescence in organ cultures of bronchial epithelium and tumor
Background: 5-Aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PPIX) fluorescence improves the differentiation of tumor and normal tissue in the bladder, skin and brain. Objective: The kinetics of 5-ALA-induced protoporphyrin IX (PPIX) fluorescence in organ cultures of normal human bronchial epithelium and cocultures of bronchial epithelium and tumor have been studied. Methods: Cultured biopsies of bronchial epithelium were exposed for 5 or 15 min, or continuously to 5-ALA. PPIX fluorescence was quantified for up to 300 min by spectroscopy. Cocultures of normal bronchial epithelium and a non-small-cell lung cancer cell line (EPLC-32M1) were incubated with 5-ALA. Space-resolved fluorescence microscopy was used to quantify PPIX fluorescence kinetics in the tumor and normal epithelium. Results: In cultures of normal epithelium, PPIX fluorescence kinetics were shown to depend on the duration of exposure to 5-ALA. There was a trend to higher fluorescence intensities with longer exposure times. In cocultures of bronchial epithelium and tumor, increases of fluorescence intensity were significantly greater in the tumor. Best tumor/normal tissue fluorescence ratios were found between 110 and 160 min after exposure to 5-ALA. Conclusion: Data obtained in this coculture system of bronchial epithelium and tumor is valuable to optimize modalities of fluorescence bronchoscopy for the diagnosis of early bronchial carcinoma. Copyright (C) 2002 S. Karger AG, Basel
Yemen: Cholera outbreak and the ongoing armed conflict
Yemen was affected by a major cholera epidemic in 2016, while a civil war, which has devastated the country since March 2015, has exacerbated the humanitarian situation. Cholera is a disease caused by the bacterium Vibrio cholera, thus this study aims to analyze the epidemiological features of the outbreak and explore the relation of the outbreak to the current armed conflict situation.
The data were obtained from the national surveillance system in Yemen. This contains details of 15,074 cases registered as suspected cholera patients per governorate from week 39 to 52 in 2016. In addition to the data concerning cholera, other data on conflict-related injuries, and population movement (numbers of Internally Displaced Persons – IDPs – and number of displaced returnees) were used to assess the correlation using Spearman's rho analysis.
The data analysis shows the intensity of the conflict as measured by the total casualties per governorate (conflict-related injuries and death) is significantly correlated with the number of cholera cases per governorate (r 0.483, P = 0.026). The analysis also shows a positive, but not significant correlation between cholera cases, and both the number of conflict internal displaced people (IDPs) (r 0.389, P = 0.081), and number of returnees (r = 432, P = 0.050).</jats:p
An Overview on Acute Malnutrition and Food Insecurity among Children during the Conflict in Yemen
Nucleosomes indicate the in vitro radiosensitivity of irradiated bronchoepithelial and lung cancer cells
Nucleosomes, which are typical cell death products, are elevated in the serum of cancer patients and are known to rapidly increase during radiotherapy. As both normal and malignant cells are damaged by irradiation, we investigated to which extent both cell types contribute to the release of nucleosomes. We cultured monolayers of normal bronchoepithelial lung cells (BEAS-2B, n = 18) and epithelial lung cancer cells (EPLC, n = 18), exposed them to various radiation doses (0, 10 and 30 Gy) and observed them for 5 days. Culture medium was changed every 24 h. Subsequently, nucleosomes were determined in the supernatant by the Cell Death Detection-ELISA(plus) ( Roche Diagnostics). Additionally, the cell number was estimated after harvesting the cells in a second preparation. After 5 days, the cell number of BEAS-2B cultures in the irradiated groups (10 Gy: median 0.03 x 10(6) cells/culture, range 0.02-0.08 x 10(6) cells/culture; 30 Gy: median 0.08 x 10(6) cells/culture, range 0.02-0.14 x 10(6) cells/culture) decreased significantly (10 Gy: p = 0.005; 30 Gy p = 0.005; Wilcoxon test) compared to the non-irradiated control group (median 4.81 x 10(6) cells/culture, range 1.50-9.54 x 10(6) cells/culture). Consistently, nucleosomes remained low in the supernatant of nonirradiated BEAS-2B. However, at 10 Gy, BEAS-2B showed a considerably increasing release of nucleosomes, with a maximum at 72 h ( before irradiation: 0.24 x 10(3) arbitrary units, AU, range 0.13-4.09 x 10(3) AU, and after 72 h: 1.94 x 10(3) AU, range 0.11-5.70 x 10(3) AU). At 30 Gy, the release was even stronger, reaching the maximum earlier (at 48 h, 11.09 x 10(3) AU, range 6.89-18.28 x 10(3) AU). In non-irradiated EPLC, nucleosomes constantly increased slightly. At 10 Gy, we observed a considerably higher release of nucleosomes in EPLC, with a maximum at 72 h (before irradiation: 2.79 x 10(3) AU, range 2.42-3.80 x 10(3) AU, and after 72 h: 7.16 x 10(3) AU, range 4.30-16.20 x 10(3) AU), which was more than 3.5 times higher than in BEAS-2B. At 30 Gy, the maximum (6.22 x 10(3) AU, range 5.13-9.71 x 10(3) AU) was observed already after 24 h. These results indicate that normal bronchoepithelial and malignant lung cancer cells contribute to the release of nucleosomes during irradiation in a dose-and time-dependent manner with cancer cells having a stronger impact at low doses. Copyright (C) 2004 S. Karger AG, Basel
Steps Toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. XII. Ground-Based Monitoring of 3C 390.3
Results of a ground-based optical monitoring campaign on 3C 390.3 in 1994-1995 are presented. The broadband fluxes (B, V, R, and I), the spectrophotometric optical continuum flux and the Fλ(5177 Å),integrated emission-line fluxes of Hᵪ Hβ, Hᵧ, He I λ5876 and He II λ4686 all show a nearly monotonic increase with episodes of milder short-term variations superposed. The amplitude of the continuum variations increases with decreasing wavelength (4400-9000 Å). The optical continuum variations follow the variations in the ultraviolet and X-ray with time delays, measured from the centroids of the cross-correlation functions, typically around 5 days, but with uncertainties also typically around 5 days; zero time delay between the high-energy and low-energy continuum variations cannot be ruled out. The strong optical emission lines Hᵪ Hβ, Hᵧ, He I λ5876 respond to the high-energy continuum variations with time delays typically about 20 days, with uncertainties of about 8 days. There is some evidence that He II λ4686 responds somewhat more rapidly, with a time delay of around 10 days, but again, the uncertainties are quite large (~8 days). The mean and rms spectra of the Hᵪ and Hβ line profiles provide indications for the existence of at least three distinct components located at ±4000 and 0 km s-1 relative to the line peak. The emission-line profle variations are largest near line center
Risk factors associated with the recent cholera outbreak in Yemen: a case-control study
OBJECTIVES The cholera outbreak in Yemen has become the largest in the recent history of cholera records, having reached more than 1.4 million cases since it started in late 2016. This study aimed to identify risk factors for cholera in this outbreak. METHODS A case-control study was conducted in Aden in 2018 to investigate risk factors for cholera in this still-ongoing outbreak. In total, 59 cholera cases and 118 community controls were studied. RESULTS The following risk factors were associated with being a cholera case in the bivariate analysis: a history of travelling and having had visitors from outside Aden Province; eating outside the house; not washing fruit, vegetables, and khat (a local herbal stimulant) before consumption; using common-source water; and not using chlorine or soap in the household. In the multivariate analysis, not washing khat and the use of common-source water remained significant risk factors for being a cholera case. CONCLUSIONS Behavioural factors and unsafe water appear to be the major risk factors in the recent cholera outbreak in Yemen. In order to reduce the risk of cholera, hygiene practices for washing khat and vegetables and the use and accessibility of safe drinking water should be promoted at the community level
Supersymmetric Large Extra Dimensions and the Cosmological Constant Problem
This article briefly summarizes and reviews the motivations for - and the
present status of - the proposal that the small size of the observed Dark
Energy density can be understood in terms of the dynamical relaxation of two
large extra dimensions within a supersymmetric higher-dimensional theory.Comment: Talk presented to Theory Canada I, Vancouver, June 2005. References
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Optical excitations of Si by time-dependent density-functional theory based on the exact-exchange Kohn-Sham band structure
We calculate the imaginary part of the frequency-dependent dielectric
function of bulk silicon by applying time-dependent density-functional theory
based on the exact-exchange (EXX) Kohn-Sham (KS) band structure and the
adiabatic local-density approximation (ALDA) kernel. The position of the E2
absorption peak calculated with the EXX band structure at the
independent-particle level is in excellent agreement with experiments, which
demonstrates the good quality of EXX `KS quasiparticles'. The excitonic E1 peak
that is missing at the independent-particle level remains absent if
two-particle interaction effects are taken into account within the
time-dependent LDA, demonstrating the incapability of the ALDA kernel to
describe excitonic effects.Comment: 6 pages, 2 figures; contribution to "DFT 2001", Sep. 10-14, San
Lorenzo de El Escorial, Spain; to be published in Int. J. Quantum. Che
Innovationen im Spezialtiefbau : Fachseminar am 05. Dezember 2013 an der Technischen Universität Berlin
Zugleich gedruckt erschienen im Universitätsverlag der TU Berlin unter der ISBN 978-3-7983-2663-7. - ISSN 1610-5648Ganz in der Tradition gemeinsamer Fachseminare von Wissenschaft und Bauwirtschaft sollen mit dem Thema „Innovationen im Spezialtiefbau“ Erkenntnisse über neue Bauverfahren, technische Herausforderungen und Lösungen vermittelt werden. Am 05.12.2013 wurden auf dem Fachseminar am Institut für Bauingenieurwesen der TU Berlin in Expertenvorträgen mit engem Praxisbezug die neuesten Entwicklungen im Spezialtiefbau, bemerkenswert innovative sowie internationale Projektbeispiele vorgestellt und diskutiert. Die Veranstaltung setzt dabei neue Akzente in der branchenweit wie auch öffentlich diskutierten Nachhaltigkeitsbetrachtung und gibt den Anstoß für weitere jährlich stattfindende Fachseminare an der TU Berlin zusammen mit dem InnovationsZentrum Bau Berlin Brandenburg und ihren Partnern aus Forschung und Praxis
Early maturation processes in coal. Part 1: Pyrolysis mass balances and structural evolution of coalified wood from the Morwell Brown Coal seam
In this work, we develop a theoretical approach to evaluate maturation
process of kerogen-like material, involving molecular dynamic reactive modeling
with a reactive force field to simulate the thermal stress. The Morwell coal
has been selected to study the thermal evolution of terrestrial organic matter.
To achieve this, a structural model is first constructed based on models from
the literature and analytical characterization of our samples by modern 1-and
2-D NMR, FTIR, and elemental analysis. Then, artificial maturation of the
Morwell coal is performed at low conversions in order to obtain, quantitative
and qualitative, detailed evidences of structural evolution of the kerogen upon
maturation. The observed chemical changes are a defunctionalization of the
carboxyl, carbonyl and methoxy functional groups coupling with an increase of
cross linking in the residual mature kerogen. Gaseous and liquids hydrocarbons,
essentially CH4, C4H8 and C14+ liquid hydrocarbons, are generated in low
amount, merely by cleavage of the lignin side chain
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