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1.
Accreditation and Quality Assurance - 相似文献
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Roberto D. Galvão Luis Gonzalo Acosta Espejo Brian Boffey 《Annals of Operations Research》2006,143(1):31-44
A study has been carried out aimed at reducing perinatal mortality in the municipality of Rio de Janeiro through a better
distribution of health care facilities. The algorithmic aspects are detailed elsewhere and here the emphasis is on practical
issues and difficulties encountered.
A 3-level hierarchical model was developed. Both uncapacitated and capacitated versions are briefly described together with
some results based on actual data. The project brought to light many contradictions between OR theory and practice in developing
countries and, unfortunately, the models developed were not implemented by the municipality health authorities. Possible reasons
for this outcome are analysed. 相似文献
4.
The incidence of the cutaneous malignant melanoma is increasing rapidly in the world [Ferlay J, Bray F, Pisani P, et al. GLOBOCAN 2000: Cancer incidence, mortality and prevalence worldwide, Version 1.0 IARC Cancer Base no. 5. Lyon: IARC Press, 2001]. The therapeutic address requires a method having high sensitivity and capability to diagnose such disease at an early stage. We introduce a new diagnostic method based on non-linear methodologies. In detail we suggest that fractal as well as noise and chaos dynamics are the most important components responsible for genetic instability of melanocytes. As consequence we introduce the new technique of the variogram and of fractal analysis extended to the whole regions of interest of skin in order to obtain parameters able to identify the malignant lesion. In a preliminary analysis, satisfactory results are reached. 相似文献
5.
Chiesa M Paganini MC Spoto G Giamello E Di Valentin C Del Vitto A Pacchioni G 《The journal of physical chemistry. B》2005,109(15):7314-7322
Paramagnetic centers at the surface of ionic oxides in the form of trapped electrons can be generated by exposure of the material to alkali metal or hydrogen atoms or of molecular hydrogen under UV irradiation. For many years, it has been assumed that the resulting paramagnetic centers consist of oxygen vacancies filled by one electron. High-resolution electron spin resonance spectra and ab initio quantum chemical calculations show that the paramagnetic centers consist of (H(+))(e(-)) electron pairs formed at morphological irregularities of the surface. At least three different kinds of (H(+))(e(-)) centers, [A], [B], and [C], have been identified with abundances of 80%, 10%, and 8%, respectively. In this work, we compare a wide set of measured and computed g-factors and hyperfine coupling constants of the unpaired electron with the surrounding (25)Mg, (17)O, and (1)H nuclei and we propose a general assignment of the centers. (H(+))(e(-)) pairs formed at Mg(4c) ions at steps and edges account for species [A], centers formed at Mg(4c) ions at reverse corners correspond to species [B], and species [C] originates from (H(+))(e(-)) pairs formed at Mg(3c) ions at corners and kinks. 相似文献
6.
Amino acids devoid of «leaving groups» on their β carbon atom (neither ? OH: serine, nor ? SH: cysteine) react with o-methoxycarbonyl-phenyl isothiocyanate (I) in the presence of one equivalent of NaOH, in water-dioxane or in ethanol, to yield the corresponding hydroquinazolinone derivatives II which were isolated as free acids. When treated with CH3COOH + conc. HCl the hydroquinazolinone resulting from the reaction of L -serine with I undergoes a nucleophilic attack of the carbon bearing the leaving group ? OH by a lone pair of electrons of S; this attack produces the formation of an additional thiazolidine ring, yielding the thiazoloquinazolinone derivative (?)-III. In an analogous reaction DL -serine phosphoric acid treated with I at pH 8–9 yields the corresponding substituted hydroquinazolinone which, boiled in 1N hydrochloric acid, undergoes ring closure to (±)-III by the same mechanism as the serine derivative (leaving group: ? OPO3H2). L -Cysteine reacted with 2 equiv. of I and then treated with CH3COOH + conc. HCl gives two products: (?)-III produced by the same mechanism as for serine (leaving group: ? SH), and the quinazolinone derivative IV where the ? SH group is also thiocarbamoylated. 相似文献
7.
3,3-Dimethylbutanol treated with polyphosphoric acid or with an equimolecular amount of POCl3 gives rise to 3,3-dimethylbutyl phosphoric acid, isolated as baryum salt (yield 20 to 30%) or as sodium salt (yield 15%). Stable in NaOH 1N at 100°C, this monoester is split at pH 4.5 and in HCl 1N much slower than choline phosphate. 相似文献
8.
Mercury-mercurous acetate indicator electrode for potentiometric titrations in anhydrous acetic acid
The authors describe a metallic mercury electrode covered with a mercurous acetate coating, its preparation, its use as an indicator electrode in anhydrous acetic acid neutralization titrations and its properties as compared with other electrodes used for the same purpose. 相似文献
9.
Mario Chiesa Maria Cristina Paganini Elio Giamello Cristiana Di Valentin Gianfranco Pacchioni 《Chemphyschem》2006,7(3):728-734
(H+)(e-) pairs generated at the surface of polycrystalline CaO are analyzed for the first time in terms of the interaction of the unpaired electron spin with the nuclear spin of the 17O anions of the surface. CaO crystals enriched in the 17O isotope are prepared and the corresponding hyperfine coupling constants are measured in electron paramagentic resonance (EPR) spectra. The results are analyzed on the basis of cluster model density functional theory calculations. The computed hyperfine coupling constants for (H+)(e-) pairs formed on the edge, corner, and reverse corner sites of the CaO surface allow a tentative assignment of two observed spectral features to specific morphological surface sites. 相似文献
10.
In research laboratories ultraviolet radiation is widely used, particularly in photochemistry and photobiology, as a sterilizing agent and for the characterization of samples. The results of a survey conducted near several university laboratories are presented with the aim of quantifying exposure levels to UV-incoherent radiation and to assess individual risk for researchers and students. It has been shown that exposure is not negligible, especially if safety procedures are neglected and personal protective equipments, described in this study, are not used. 相似文献