1,028 research outputs found
Spin and pseudospin symmetries in the antinucleon spectrum of nuclei
Spin and pseudospin symmetries in the spectra of nucleons and antinucleons
are studied in a relativistic mean-field theory with scalar and vector
Woods-Saxon potentials, in which the strength of the latter is allowed to
change. We observe that, for nucleons and antinucleons, the spin symmetry is of
perturbative nature and it is almost an exact symmetry in the physical region
for antinucleons. The opposite situation is found in the pseudospin symmetry
case, which is better realized for nucleons than for antinucleons, but is of
dynamical nature and cannot be viewed in a perturbative way both for nucleons
and antinucleons. This is shown by computing the spin-orbit and
pseudospin-orbit couplings for selected spin and pseudospin partners in both
spectra.Comment: 8 figures, uses revtex 4.1 macro
Production of Melanin Pigment by Fungi and Its Biotechnological Applications
Production of the microbial pigments is one of the emerging fields of research due to a growing interest of the industry for safer products, easily degradable and eco-friendly. Fungi constitute a valuable source of pigments because they are capable of producing high yields of the substance in the cheap culture medium, making the bioprocess economically viable on the industrial scale. Some fungal species produce a dark-brown pigment, known as melanin, by oxidative polymerization of phenolic compounds, such as glutaminyl-3,4-dihydroxybenzene (GDHB) or catechol or 1,8-dihydroxynaphthalene (DHN) or 3,4-dihydroxyphenylalanine (DOPA). This pigment has been reported to act as “fungal armor” due to its ability to protect fungi from adverse conditions, neutralizing oxidants generated in response to stress. Apart from the scavenging activity, melanin exhibits other biological activities, including thermoregulatory, radio- and photoprotective, antimicrobial, antiviral, cytotoxic, anti-inflammatory, and immunomodulatory. Studies have shown that the media composition and cultivation conditions affect the pigment production in fungi and the manipulation of these parameters can result in an increase in pigment yield for large-scale pigment production. This chapter presents a comprehensive discussion of the research on fungal melanin, including the recently discovered biological activities and the potential use of this pigment for various biotechnological applications in the fields of biomedicine, dermocosmetics, materials science, and nanotechnology
Relating pseudospin and spin symmetries through charge conjugation and chiral transformations: the case of the relativistic harmonic oscillator
We solve the generalized relativistic harmonic oscillator in 1+1 dimensions,
i.e., including a linear pseudoscalar potential and quadratic scalar and vector
potentials which have equal or opposite signs. We consider positive and
negative quadratic potentials and discuss in detail their bound-state solutions
for fermions and antifermions. The main features of these bound states are the
same as the ones of the generalized three-dimensional relativistic harmonic
oscillator bound states. The solutions found for zero pseudoscalar potential
are related to the spin and pseudospin symmetry of the Dirac equation in 3+1
dimensions. We show how the charge conjugation and chiral
transformations relate the several spectra obtained and find that for massless
particles the spin and pseudospin symmetry related problems have the same
spectrum, but different spinor solutions. Finally, we establish a relation of
the solutions found with single-particle states of nuclei described by
relativistic mean-field theories with scalar, vector and isoscalar tensor
interactions and discuss the conditions in which one may have both nucleon and
antinucleon bound states.Comment: 33 pages, 10 figures, uses revtex macro
Detecção de ovino sororreagente para Maedi-Visna no estado de Sergipe.
Resumo - O vírus da Maedi-Visna pertence à família Retroviridae, gênero Lentivírus e afeta ovinos criados especialmente de forma intensiva. Apesar de variável patogenicidade, é responsável por manifestação clínica crônica e debilitante. Amplamente distribuído pelo mundo, é relacionado a subestimado impacto econômico na ovinocultura, porém com dados imprecisos no Brasil. O presente trabalho objetivou a obtenção da prevalência da Maedi-Visna no município de Lagarto/Sergipe. Foram analisadas 151 amostras séricas de ovinos Santa Inês, oriundas de nove propriedades rurais, identificadas quanto ao sexo e idade dos animais. Utilizou-se o teste de Imunodifusão em Gel de Ágar através da técnica de microaglutinação. A prevalência obtida foi de 0,66%, o que representa o primeiro relato da Maedi-Visna em Sergipe e que pode estar correlacionado ao íntimo contato entre ovinos e caprinos ou a submissão dos animais às exposições agropecuárias, inclusive extra-estaduais, onde há a aproximação de animais infectados e sadios promovida de forma inconsciente pelos produtores, ou ainda à transmissão a partir de animais exóticos inseridos em rebanho para melhoramento genético. Devido ao sistema de criação ao qual os animais são mantidos, confinamento de reprodutores e regime semi-intensivo aos demais, a doença pode não ter conseguido condições propicias para disseminar-se. O resultado indica riscos à ovinocultura desenvolvida no estado e as relações comerciais com os demais, e sugere a necessidade de estudos mais amplos para melhor caracterizar o perfil do estado em relação à ocorrência de Lentiviroses de Pequenos Ruminantes e implantação de medidas de controle e prevenção da disseminação desta enfermidade. Detection of sheep sororeaction for maedi-visna in State of Sergipe. Abstract - The virus of Maedi Visna belongs to Retroviridae family, gender Lentivirus affects raise of sheep especially at intensive way. Despite variable pathogenicity, is responsible for chronic and debilitating clinical. Widely distributed throughout the world, is linked underestimated the economic impact in raise of sheep, but with inaccurate data in Brazil. This study aimed to obtain the prevalence of Maedi Visna in the municipality of Lagarto / Sergipe. It were analyzed 151 samples of serum taken from sheep of Santa Ines breed, from nine farms, identified as to sex and age of animals. It was used in the test of Imunodifusion in Agar Gel whith microaglutination technique. The prevalence obtained was 0.66%, which represents the first report of Maedi Visna in Sergipe and can be correlated to the close contact between sheep and goats or the submission of animals for agricultural exhibitions where there is the nearest of infected and healthy animals unconscious promoted by producers or the transmission from exotic animals entered in farms for breeding herd. Because the system of creation which animals are kept, confinement of males and semi-intensive system to the others, the disease may not have achieved favorable conditions to spread itself. The results indicates the risk in raised of sheep developed in the state and trade relations with the others, and suggests the need for more extensive studies to better characterize the profile of the state in relation to the occurrence of Lentiviroses of Small Ruminants and implementation of measures for control and prevention spread of this disease
Neutrophil to lymphocyte count ratio as an early indicator of blood stream infection in the emergency department
Objectives Early identification of patients with blood stream infection (BSI), especially bacteraemia, is important as prompt treatment improves outcome. The initial stages of severe infection may be characterised by increased numbers of neutrophils in the peripheral blood and depression of the lymphocyte count (LC). The neutrophil to LC ratio (NLCR) has previously been compared with conventional tests, such as C-reactive protein (CRP) and white cell count (WCC), and has been proposed as a useful marker in the timely diagnosis of bacteraemia.
Methods Data on consecutive adult patients presenting to the emergency department with pyrexial illness during the study period, November 2009 to October 2010, were analysed. The main outcome measure was positive blood cultures (bacteraemia). Sensitivity, specificity, positive and negative predictive values and likelihood ratios were determined for NLCR, CRP, WCC, neutrophil count and LC.
Results 1954 patients met the inclusion criteria. Blood cultures were positive in 270 patients, hence the prevalence of bacteraemia was 13.8%. With the exception of WCC, there were significant differences in the mean value for each marker between bacteraemic and non-bacteraemic patients (p<0.001). The area under the receiver operating characteristic curve was highest for NLCR (0.72; 95% CI 0.69 to 0.75) and LC (0.71; 0.68 to 0.74) and lowest for WCC (0.54; 0.40 to 0.57). The sensitivity and specificity of NLCR for predicting bacteraemia were 70% (64% to 75%) and 57% (55% to 60%), respectively. Positive and negative predictive values for NLCR were 0.20 (0.18 to 0.23) and 0.92 (0.91 to 0.94), respectively. The positive likelihood ratio was 1.63 (1.48 to 1.79) and the negative likelihood ratio was 0.53 (0.44 to 0.64).
Conclusions Although NLCR outperforms conventional markers of infection, it is insufficient in itself to guide clinical management of patients with suspected BSI, and it offers no advantage over LC. However, it may offer some diagnostic utility when taken into account as part of the overall assessment
Reunião anual conjunta dos projetos Robin e Amazalert: excursão técnica.
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