291 research outputs found

    FLOW ANALYSIS AND MODELING OF THE LAKE ÁGUA PRETA: WATER SOURCE OF THE BELÉM METROPOLITAN AREA

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    The natural conditions of water resources can be modified with the unsustainable use of them. For example, in Belém, capital of Pará State, Água Preta Lake has a history of degradation jeopardize the drinking water supply in Belém. Thus, the main contribution of this work is to develop a study on modeling hydrodynamic study of Água Preta Lake. Such study is carried through the bathymetric of 2009 performed with an ADCP. The bathymetry and substrate data that composes the Lake and its boundary. The bathymetry data are used to construct the digital elevation model, with the coordinates x, y and z in UTM; while the composition of the substrate is used for the determination of the Manning coefficient. The coordinates x, y, z and Manning coefficient are used in the hydrodynamic model. This one is the classic model of Saint-Venant. In this case, a vertical integration is applied to the three-dimensional equations of Navier-Stokes for incompressible flow with outline conditions, of bottom and of liquid and solid surface, included. Thus, the problem becomes two-dimensional (2D) and the values obtained for velocities are medium in the vertical direction. The velocities are the input data for the many models, such as pollutant dispersion sediment transport and aquatic fauna and flora habitats. Thus, besides of hydrodynamic model explains the patterns of flow in the lake, it can be employed for the others models of the Lake Água Preta

    Enhancement of gene targeting in human cells by intranuclear permeation of the Saccharomyces cerevisiae Rad52 protein

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    The introduction of exogenous DNA in human somatic cells results in a frequency of random integration at least 100-fold higher than gene targeting (GT), posing a seemingly insurmountable limitation for gene therapy applications. We previously reported that, in human cells, the stable over-expression of the Saccharomyces cerevisiae Rad52 gene (yRAD52), which plays the major role in yeast homologous recombination (HR), caused an up to 37-fold increase in the frequency of GT, indicating that yRAD52 interacts with the double-strand break repair pathway(s) of human cells favoring homologous integration. In the present study, we tested the effect of the yRad52 protein by delivering it directly to the human cells. To this purpose, we fused the yRAD52 cDNA to the arginine-rich domain of the TAT protein of HIV (tat11) that is known to permeate the cell membranes. We observed that a recombinant yRad52tat11 fusion protein produced in Escherichia coli, which maintains its ability to bind single-stranded DNA (ssDNA), enters the cells and the nuclei, where it is able to increase both intrachromosomal recombination and GT up to 63- and 50-fold, respectively. Moreover, the non-homologous plasmid DNA integration decreased by 4-fold. yRAD52tat11 proteins carrying point mutations in the ssDNA binding domain caused a lower or nil increase in recombination proficiency. Thus, the yRad52tat11 could be instrumental to increase GT in human cells and a ‘protein delivery approach’ offers a new tool for developing novel strategies for genome modification and gene therapy applications

    Systematic review of 3D mammography for breast cancer screening.

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    AbstractThis review investigated the relative performance of digital breast tomosynthesis (DBT) (alone or with full field digital mammography (FFDM) or synthetic digital mammography) compared with FFDM alone for detecting breast cancer lesions in asymptomatic women. A systematic review was carried out according to systematic reviewing principles provided in the Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy. A protocol was developed a priori. The review was registered with PROSPERO (number CRD42014013949). Searches were undertaken in October 2014. Following selection, five studies were eligible. Higher cancer detection rates were observed when comparing DBT + FFDM with FFDM in two European studies: the summary difference per 1000 screens was 2.43 (95% CI: 1.8 to 3.1). Both European studies found lower false positive rates for individual readers. One found a lower recall rate based on conditional recall. The second study was not designed to compare post-arbitration recall rates between FFDM and DBT + FFDM. One European study presented data on interval cancer rates; sensitivity and specificity for DBT + FFDM were both higher compared to FFDM. One large multicentre US study showed a higher cancer detection rate for DBT + FFDM, while two smaller US studies did not find statistically significant differences. Reductions in recall and false positive rates were observed in the US studies in favour of DBT + FFDM. In comparison to FFDM, DBT, as an adjunct to FFDM, has a higher cancer detection rate, increasing the effectiveness of breast cancer screening. Additional benefits of DBT may also include reduced recalls and, consequently, reduced costs and distress caused to women who would have been recalled

    The IARC perspective on cervical cancer screening

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    In May 2018, the World Health Organization (WHO) called for a global initiative to eliminate cervical cancer as a public health problem. To achieve this goal, global scale-up of effective vaccination against the human papillomavirus (HPV) as well as screening for and treatment of cervical cancer are required. Cervical cancer screening was evaluated in 2005 by the International Agency for Research on Cancer (IARC) Handbooks program,1 and a reevaluation was deemed to be timely given the major advances in the field since then. The new handbook provides updated evaluations of the effectiveness of screening methods, which were used as a basis for the update of the WHO Guideline for Screening and Treatment of Cervical Pre-cancer Lesions for Cervical Cancer Prevention.2 We convened an IARC Working Group of 27 scientists from 20 countries to assess the evidence on the current approaches to and technologies used in cervical cancer screening with the use of the newly updated Handbooks Preamble3 (Fig. 1) and Table 1).Fil: Bouvard, Véronique. International Agency For Research On Cancer; FranciaFil: Wentzensen, Nicolas. National Cancer Institute; Estados UnidosFil: Mackie, Anne. Public Health England; Reino UnidoFil: Berkhof, Johannes. University of Amsterdam; Países BajosFil: Brotherton, Julia. VCS Foundation; Australia. University of Melbourne; AustraliaFil: Giorgi Rossi, Paolo. Azienda Unità Sanitaria Locale Di Reggio Emilia; ItaliaFil: Kupets, Rachel. University of Toronto; CanadáFil: Smith, Robert. American Cancer Society; Estados UnidosFil: Arrossi, Silvina. Centro de Estudios de Estado y Sociedad; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bendahhou, Karima. Casablanca Cancer Registry; MarruecosFil: Canfell, Karen. The University Of Sydney; AustraliaFil: Chirenje, Z. Mike. University Of Zimbabwe; ZimbabueFil: Chung, Michael H.. University of Emory; Estados UnidosFil: del Pino, Marta. Hospital Clinico de Barcelona; EspañaFil: de Sanjosé, Silvia. Program for Appropriate Technology in Health; Estados UnidosFil: Elfström, Miriam. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Franco, Eduardo L.. McGill University; CanadáFil: Hamashima, Chisato. Teikyo University; JapónFil: Hamers, Françoise F.. French National Public Health Agency; FranciaFil: Herrington, C. Simon. University of Edinburgh; Reino UnidoFil: Murillo, Raúl. Hospital Universitario San Ignacio; ColombiaFil: Sangrajrang, Suleeporn. National Cancer Institute; TailandiaFil: Sankaranarayanan, Rengaswamy. Research Triangle Institute; Estados UnidosFil: Saraiya, Mona. Centers for Disease Control and Prevention; Estados UnidosFil: Schiffman, Mark. National Cancer Institute; Estados UnidosFil: Zhao, Fanghui. Chinese Academy of Medical Sciences & Peking Union Medical College; ChinaFil: Arbyn, Marc. Sciensano; BélgicaFil: Prendiville, Walter. International Agency For Research On Cancer; FranciaFil: Indave Ruiz, Blanca I.. International Agency For Research On Cancer; FranciaFil: Mosquera Metcalfe, Isabel. International Agency For Research On Cancer; FranciaFil: Lauby Secretan, Béatrice. International Agency For Research On Cancer; Franci

    An efficient strategy for evaluating new non-invasive screening tests for colorectal cancer: the guiding principles.

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    New screening tests for colorectal cancer (CRC) are rapidly emerging. Conducting trials with mortality reduction as the end point supporting their adoption is challenging. We re-examined the principles underlying evaluation of new non-invasive tests in view of technological developments and identification of new biomarkers. A formal consensus approach involving a multidisciplinary expert panel revised eight previously established principles. Twelve newly stated principles emerged. Effectiveness of a new test can be evaluated by comparison with a proven comparator non-invasive test. The faecal immunochemical test is now considered the appropriate comparator, while colonoscopy remains the diagnostic standard. For a new test to be able to meet differing screening goals and regulatory requirements, flexibility to adjust its positivity threshold is desirable. A rigorous and efficient four-phased approach is proposed, commencing with small studies assessing the test's ability to discriminate between CRC and non-cancer states (phase I), followed by prospective estimation of accuracy across the continuum of neoplastic lesions in neoplasia-enriched populations (phase II). If these show promise, a provisional test positivity threshold is set before evaluation in typical screening populations. Phase III prospective studies determine single round intention-to-screen programme outcomes and confirm the test positivity threshold. Phase IV studies involve evaluation over repeated screening rounds with monitoring for missed lesions. Phases III and IV findings will provide the real-world data required to model test impact on CRC mortality and incidence. New non-invasive tests can be efficiently evaluated by a rigorous phased comparative approach, generating data from unbiased populations that inform predictions of their health impact

    Unrecorded alcohol consumption in Russia: toxic denaturants and disinfectants pose additional risks

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    In 2005, 30% of all alcohol consumption in Russia was unrecorded. This paper describes the chemical composition of unrecorded and low cost alcohol, including a toxicological evaluation. Alcohol products (n=22) from both recorded and unrecorded sources were obtained from three Russian cities (Saratov, Lipetsk and Irkutsk) and were chemically analyzed. Unrecorded alcohols included homemade samogons, medicinal alcohols and surrogate alcohols. Analysis included alcoholic strength, levels of volatile compounds (methanol, acetaldehyde, higher alcohols), ethyl carbamate, diethyl phthalate (DEP) and polyhexamethyleneguanidine hydrochloride (PHMG). Single samples showed contamination with DEP (275–1269 mg/l) and PHMG (515 mg/l) above levels of toxicological concern. Our detailed chemical analysis of Russian alcohols showed that the composition of vodka, samogon and medicinal alcohols generally did not raise major public health concerns other than for ethanol. It was shown, however, that concentration levels of DEP and PHMG in some surrogate alcohols make these samples unfit for human consumption as even moderate drinking would exceed acceptable daily intakes
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