524 research outputs found

    Brazilian gamma detection device for sentinel lymph node biopsy

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    OBJECTIVE: To test the effectiveness of an intra-operative gamma detection Brazilian device (IPEN) on sentinel lymph node biopsy (SLNB) procedures. METHODS: Forty melanoma or breast cancer patients with indication for undergoing SLNB were studied. Lymphoscintigraphy was done 2 to 24 hours prior to surgery. Lymphatic mapping with vital dye and gamma detection were performed intraoperatively. For gamma detection Neoprobe ® 1500 was used followed by IPEN (equipment under test) in the first 20 patients and for the remaining half IPEN was used first to verify its ability to locate the sentinel node (SN). Measurements were taken from the radiopharmaceutical product injection site, from SN (in vivo and ex vivo) and from background. It was recorded if the SN was stained or not and if it was found easily by surgeon. RESULTS: There were 33 (82.5%) breast cancer and 7 (17.5%) melanoma patients. Ages varied from 21 to 68 year-old (median age of 46). Sex distribution was 35 (87.5%) women and 5 (12.5%) men. Sentinel node was found in all but one patient. There was no statistical difference between the reasons ex vivo/ background obtained with the measures of both equipments (p=0, 2583-ns). The SN was easily found by the surgeon with both devices. CONCLUSION: The SLNB was successfully performed using either equipment. It was possible to do SLNB with the Brazilian device developed by IPEN without prejudice for the patient.OBJETIVO: Testar a eficácia de equipamento de detecção gama intra-operatória (DGI) desenvolvido pelo IPEN (Brasil), em procedimentos de biópsia de linfonodo sentinela (BLS) no melanoma e no câncer de mama. MÉTODOS: Foram estudados 40 pacientes portadores de melanoma ou câncer de mama com indicação para realização de BLS.Todos pacientes foram submetidos à linfocintilografia e a BLS ocorreu entre 2 a 24 horas após a mesma. Concomitantemente à DGI, realizou-se o mapeamento linfático com corante vital. Foram feitas leituras com o equipamento convencional Neoprobe® 1500 e com o equipamento em teste (IPEN) dos valores de captação do sítio de injeção do radiofármaco, do LS in vivo e ex vivo e da captação de fundo. Foi registrado se o LS estava corado e se o cirurgião teve facilidade para encontrá-lo. Nos primeiros 20 pacientes utilizou-se o equipamento convencional e depois o de teste; nos outros 20, utilizou-se primeiro o equipamento em teste, com objetivo de verificar se o mesmo identificava primariamente o LS. RESULTADOS: Dos quarenta pacientes, 33 eram portadores de tumor de mama e sete de melanoma cutâneo; variação da idade: 21 a 68 anos (mediana= 46 anos); 35 mulheres e 5 homens. Em apenas um paciente o LS não foi encontrado, nem pela DGI nem pelo corante vital. Não houve diferença estatística entre as razões ex vivo/fundo obtidas com os dois equipamentos (p=0, 2583-ns). CONCLUSÃO: É possível realizar o procedimento de BLS com o equipamento brasileiro desenvolvido pelo IPEN, com facilidade e sem prejuízo para o paciente.Hospital Israelita Albert EinsteinIPENUniversidade Federal de São Paulo (UNIFESP)Faculdade de Medicina Anhembi-MorumbiUNIFESPSciEL

    Growing at the limit: Reef growth sensitivity to climate and oceanographic changes in the South Western Atlantic

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordWhilst the impacts of climatic and oceanographic change on lower latitude reefs are increasingly well documented, our understanding of how reef-building has fluctuated in higher latitude settings remains limited. Here, we explore the timing and longevity of reef-building through the mid- to late Holocene in the most southerly known reef (24°S) in the Western Atlantic. Reef core data show that reef growth was driven by a single coral species, Madracis decactis, and occurred over two phases since ~6000 calibrated (cal.) yr B.P.. These records further indicate that there was a clear growth hiatus from ~5500 to 2500 cal. yr B.P., and that there is no evidence of reef accretion on the Queimada Grande Reef (QGR) over the past 2000 yrs. It thus presently exists as a submerged senescent structure colonized largely by non-reef building organisms. Integration of these growth data with those from sites further north (18°S and 21°S) suggests that Intertropical Convergence Zone (ITCZ), South Westerlies Winds (SWW) and El Niño-Southern Oscillation (ENSO) variability and shifts during the Holocene drove changes in the position of the Brazil-Falklands/Malvinas Confluence (BFMC), and that this has had a strong regional influence on the timing and longevity of reef growth. Our results add new evidence to the idea that reef growth in marginal settings can rapidly turn-on or -off according to regional environmental changes, and thus are of relevance for predicting high latitude reef growth potential under climate change.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)razilian Research Council (CNPq

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

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    The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

    Search for pair-produced long-lived neutral particles decaying to jets in the ATLAS hadronic calorimeter in ppcollisions at √s=8TeV

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    The ATLAS detector at the Large Hadron Collider at CERN is used to search for the decay of a scalar boson to a pair of long-lived particles, neutral under the Standard Model gauge group, in 20.3fb−1of data collected in proton–proton collisions at √s=8TeV. This search is sensitive to long-lived particles that decay to Standard Model particles producing jets at the outer edge of the ATLAS electromagnetic calorimeter or inside the hadronic calorimeter. No significant excess of events is observed. Limits are reported on the product of the scalar boson production cross section times branching ratio into long-lived neutral particles as a function of the proper lifetime of the particles. Limits are reported for boson masses from 100 GeVto 900 GeV, and a long-lived neutral particle mass from 10 GeVto 150 GeV

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at root s = 8 TeV with the ATLAS detector (vol 75, 299, 2015)

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √s=8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT>120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between EmissT>150 GeV and EmissT>700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presented

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at root s = 8 TeV with the ATLAS detector (vol 75, 299, 2015)

    Get PDF
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