Transfer reactions and the dispersive optical-model

The dispersive optical-model is applied to transfer reactions. A systematic study of $(d,p)$ reactions on closed-shell nuclei using the finite-range adiabatic reaction model is performed at several beam energies and results are compared to data as well as to predictions using a standard global optical-potential. Overall, we find that the dispersive optical-model is able to describe the angular distributions as well as or better than the global parameterization. In addition, it also constrains the overlap function. Spectroscopic factors extracted using the dispersive optical-model are generally lower than those using standard parameters, exhibit a reduced dependence on beam energy, and are more in line with results obtained from $(e,e'p)$ measurements.Comment: Phys. Rev. C 84, 044611 (2011

Patient-controlled analgesia com morfina endovenosa no tratamento da dor aguda

INTRODUÇÃO: O manuseio da dor aguda (DA) é um desafio na Anestesiologia. PCA (patient-controlled analgesia) com opióide endovenoso (ev) permite administração de opióide on-demand, de forma intermitente, controlada pelo doente. No nosso serviço é usada PCA de morfina ev (protocolo mais usado: bólus 1mg, lockout 7 minutos, sem perfusão contínua). O conhecimento da forma como é utilizada permite-nos melhorar protocolos. OBJETIVOS: Avaliar o uso de PCA com morfina ev no nosso hospital e caraterizar a população de doentes considerando três grupos no que respeita ao consumo total de morfina. MATERIAL E MÉTODOS: Avaliação retrospetiva do processo clínico eletrónico dos doentes referenciados à Unidade de Dor Aguda (UDA) do nosso hospital nos últimos 2 anos. Consulta dos registos da UDA e fichas anestésicas de todos os doentes com analgesia com morfina ev por PCA. Registo de sexo, idade, estado físico ASA, tipo de dor, intervenção cirúrgica, perfusão contínua e total de morfina considerando grupos: 1 (40mg). Excluídos doentes com registos incompletos. Aplicados teste Qui quadrado e índice de correlação de Pearson. Resultados apresentados em percentagem (%) e média ± desvio padrão. Significância estatística P<0.05. RESULTADOS E DISCUSSÃO: Excluídos 3 doentes por registos incompletos. Analisados 930. Masculino (M) 51.1%, Idade - 50.7± 19.6 anos, maioritariamente ASA II - 46.1%. Tempo com PCA 2.7 ± 2.5 dias. Dor pós-operatória (DPO) - 95.5%, dor isquémica (DI) - 1.8%, dor traumática (DT) - 1.2%, outra (O) - 1.6%. Ratio bólus pedidos/administrados (P/A) 2.08 ± 3 (50%), encontrando-se relação com a idade: R=0.128 (P<0.01). Perfusão contínua - 4.2% dos casos sendo GRUPO 1- 2.7%; GRUPO 2 - 5.4% e GRUPO 3 - 91.9%. Consumo de morfina - GRUPO 1: DPO - 31.2%, mais frequente cirurgia membro superior - 67.4%; DI - 6.3%; DT - 9.1%; O - 8.3%. GRUPO 2: DPO - 25.4%, mais frequente cirurgia cabeça e pescoço - 40.0%; DI - 6.3%; DT - 18.2%; O - 16.7%. GRUPO 3: DPO - 43.4%, mais frequente cirurgia vascular membro inferior - 82.1% e cirurgia de escoliose - 74.2%; DI - 87.5%; DT - 72.7%; O - 75%. As diferenças de consumos são estatisticamente significativas entre o tipo de dor, intervenção cirúrgica, presença ou não perfusão contínua e classificação ASA (P<0.001). Não existe diferença entre sexo. Dias com PCA, perfusão contínua e intervenção cirúrgica têm importância preditiva no consumo total de morfina (aplicação do modelo linear). CONCLUSÃO: Os resultados mostram maior utilização da PCA na DPO. DI e DT surgem associadas a maior consumo total de morfina. Na DPO, o maior consumo de morfina verifica-se na cirurgia vascular do membro inferior e cirurgia de escoliose; cirurgias de cabeça e pescoço e membro superior estão associadas a menor consumo. O aumento do ratio P/A com a idad

Are spectroscopic factors from transfer reactions consistent with asymptotic normalisation coefficients?

It is extremely important to devise a reliable method to extract spectroscopic factors from transfer cross sections. We analyse the standard DWBA procedure and combine it with the asymptotic normalisation coefficient, extracted from an independent data set. We find that the single particle parameters used in the past generate inconsistent asymptotic normalization coefficients. In order to obtain a consistent spectroscopic factor, non-standard parameters for the single particle overlap functions can be used but, as a consequence, often reduced spectroscopic strengths emerge. Different choices of optical potentials and higher order effects in the reaction model are also studied. Our test cases consist of: $^{14}$C(d,p)$^{15}$C(g.s.) at $E_d^{lab}=14$ MeV, $^{16}$O(d,p)$^{17}$O(g.s.) at $E_d^{lab}=15$ MeV and $^{40}$Ca(d,p)$^{41}$Ca(g.s.) at $E_d^{lab}=11$ MeV. We underline the importance of performing experiments specifically designed to extract ANCs for these systems.Comment: 15 pages, 12 figures, Phys. Rev. C (in press

Stability of antiphase line defects in nanometer-sized boron-nitride cones

We investigate the stability of boron nitride conical sheets of nanometer size, using first-principles calculations. Our results indicate that cones with an antiphase boundary (a line defect that contains either B-B or N-N bonds) can be more stable than those without one. We also find that doping the antiphase boundaries with carbon can enhance their stability, leading also to the appearance of localized states in the bandgap. Among the structures we considered, the one with the smallest formation energy is a cone with a carbon-modified antiphase boundary that presents a spin splitting of about 0.5 eV at the Fermi level.Comment: 5 two-column pages with 2 figures Accepted for publication in Physical Review B (vol 70, 15 Nov.

Evaluation of the toxicity of the mixture of diflubenzuron and p-chloroaniline in tilapia fish in the presence and absence of soil.

aBSTRACT: Several chemicals occur together in the environment as a result of different sources. However, in the great majority of risk assessments only a single chemical is considered. Diflubenzuron (DFB), the most used compound to combat parasites in aquaculture, can be toxic for non-target species. When degraded, it generates p-chloroaniline (PCA), a potentially carcinogenic and mutagenic compound. This study analyzed the activity of the enzymes: Catalase (CAT), acid and alkaline Phosphatase (ACP/ALP) of the gills of the Tilapia fish (Oreochromis niloticus) exposed to different concentrations of the mixture of DFB and PCA in the presence and absence of soil

New sources of resistance to Myrothecium roridum and Podosphaeria xanthii in yellow melon.

The aim of this study was to identify sources of resistance to Myrothecium roridum and Podosphaeria xanthii. Initially, 86 inbred lines of the crossing AM-04 x Goldex, 91 inbred lines of the crossing AM-12 x Rochedo, and 75 inbred lines of the crossing ACP x AF-646 were evaluated. The trials were carried out in a greenhouse in a randomized block design with five replications. Seventeen inbred lines were identified as resistant to M. roridum. These inbred lines, as well as the parents and seven differential cultivars (checks) were evaluated for the reaction to P. xanthii. Ten inbred lines were selected as moderately resistant to M. roridumand resistant to P. xanthii