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Unknown Composition (unknown + composition)
Selected AbstractsThe widespread use of skin lightening creams in Senegal: a persistent public health problem in West AfricaINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 2 2002Pascal Del Giudice MD Background The use of skin lightening creams is common in the female population of some African countries. The long-term use of certain products for several months to years may cause cutaneous adverse effects. Methods From 1992 to 1993, we conducted an epidemiologic and clinical study in Dakar, Senegal. Women were questioned about the use of skin lightening creams and examined for potential adverse skin reactions. Six hundred and eighty-five Senegalese women participated in the study. Results Twenty-six per cent of women were using skin lightening creams at the time and 36% had used them at some time. The most common products used were hydroquinone and corticosteroids, but 25% of women had used products of unknown composition. Seventy-five per cent of women using such creams showed cutaneous adverse effects. Facial acne was the most common adverse effect. Conclusions A major part of the female adult population of Senegal used skin lightening creams. The long-term use of these creams is responsible for a high rate of cutaneous adverse effects. This practice has also been reported in other countries from sub-Saharan Africa and suggests a widespread use in the African population. [source] Fluorescence and Raman spectra on painting materials: reconstruction of spectra with mathematical methodsJOURNAL OF RAMAN SPECTROSCOPY, Issue 10 2006Iacopo Osticioli Abstract SERDS (shift excitation difference spectroscopy) and SSRS (subtracted shifted Raman spectroscopy) methods were applied for fluorescence-background rejection in the Raman spectra of colored materials. These techniques are based on the assumption that the fluorescence contribution can be completely eliminated by subtracting two Raman spectra acquired at two shifted laser excitation frequencies. For the SERDS method a micro-Raman experimental apparatus coupled with a tunable diode laser (central emission at 684 nm) was set up. SSRS measurements were made on a commercial micro-Raman instrument; in this case the shifted spectrum was obtained by moving the spectrometer grating. Raman spectra were then reconstructed by applying the difference deconvolution method that automatically converts the difference signals in Raman peaks through a deconvolution operation. These techniques were tested on two reference colors (ultramarine and 6,6,-dibromoindigotine) and two colored samples of unknown composition (a Pompeian pink powder and a blue paint from a XVII century painting). Fluorescence-background subtraction and the following operation of spectra reconstruction took place successfully with no errors in Raman peaks, width and wavenumber position. In addition, even weak spectral details were revealed favoring the comparison with reference data for a molecular identification. Copyright © 2006 John Wiley & Sons, Ltd. [source] Phosphorus L2,3 -edge XANES: overview of reference compoundsJOURNAL OF SYNCHROTRON RADIATION, Issue 2 2009Jens Kruse Synchrotron-based X-ray absorption near-edge structure (XANES) spectroscopy is becoming an increasingly used tool for the element speciation in complex samples. For phosphorus (P) almost all XANES measurements have been carried out at the K -edge. The small number of distinctive features at the P K -edge makes in some cases the identification of different P forms difficult or impossible. As indicated by a few previous studies, the P L2,3 -edge spectra were richer in spectral features than those of the P K -edge. However, experimentally consistent spectra of a wide range of reference compounds have not been published so far. In this study a library of spectral features is presented for a number of mineral P, organic P and P-bearing minerals for fingerprinting identification. Furthermore, the effect of radiation damage is shown for three compounds and measures are proposed to reduce it. The spectra library provided lays a basis for the identification of individual P forms in samples of unknown composition for a variety of scientific areas. [source] The Preclinical Pharmacology of BIBN4096BS, a CGRP AntagonistCARDIOVASCULAR THERAPEUTICS, Issue 1 2005Debbie L. Hay ABSTRACT CGRP is an important neuropeptide found throughout the cardiovascular system. However, until recently it has been difficult to define its pharmacology or physiological role because of the lack of suitable antagonists. BIBN4096BS is a high-affinity, non-peptide antagonist that shows much greater selectivity for human CGRP1 receptors compared to any other drug. Its pharmacology has been defined with studies on transfected cells or cell lines endogenously expressing receptors of known composition. These have allowed confirmation that in many human blood vessels, CGRP is working via CGRP1 receptors. However, it also interacts with other CGRP-activated receptors, of unknown composition. In vivo, clinical studies have shown that BIBN4096BS is likely to be useful in the treatment of migraine. It has also been used to define the role of CGRP in phenomena such as plasma extravasation and cardioprotection following ischemia. [source] | |||||||||||||