192 research outputs found
Vacinação obrigatória contra a influenza dos profissionais da saúde na América Latina: suporte ético e bioético
Os profissionais da saúde representam possíveis fontes de infecção e, ao mesmo tempo, são as fontes de informação mais confiáveis para recomendar a vacinação a seus pacientes. Porém, as políticas de imunização voluntária desses profissionais apresentam índices tragicamente inexpressivos em todo o mundo. Isto exige revisão profunda dessas práticas substituindo-as por medidas mais incisivas como sua vacinação obrigatória anual contra a influenza, como é adotada nos Estados Unidos, sendo discutida na Europa e recomendada no Brasil. Método: Revisão bibliográfica para suporte à reflexão sobre os aspectos éticos e bioéticos da vacinação compulsória anual contra a influenza dos profissionais da saúde
Comitês Nacionais de Bioética na União Europeia: contribuição para a discussão na América Latina
Estimulados e apoiados pela Unesco muitos países criaram órgãos consultivos denominados de Conselho/Comitê Nacional de Bioética. Suas competências maiores são: estudar e promover reflexões éticas sobre o valor e a importância das novas tecnologias, os procedimentos em evolução na medicina e sua aplicação na saúde humana e nas ciências da vida visando recomendar possíveis soluções à s autoridades, com primordial papel na educação bioética ao público em geral. Alguns países da América Latina e Caribe possuem CNB em funcionamento, enquanto outros apenas aprovaram leis de criação e alguns nada projetam. No Brasil, ocorreram tentativas frustradas. O presente estudo objetivou estimular e subsidiar estes países a discutirem a perspectiva de seu aprimoramento ou implantação
Oxygen impurities in NiAl: Relaxation effects
We have used a full-potential linear muffin-tin orbital method to calculate
the effects of oxygen impurities on the electronic structure of NiAl. Using the
supercell method with a 16-atom supercell we have investigated the cases where
an oxygen atom is substitutionally placed at either a nickel or an aluminum
site. Full relaxation of the atoms within the supercell was allowed. We found
that oxygen prefers to occupy a nickel site over an aluminum site with a site
selection energy of 138 mRy (21,370 K). An oxygen atom placed at an aluminum
site is found to cause a substantial relaxation of its nickel neighbors away
from it. In contrast, this steric repulsion is hardly present when the oxygen
atom occupies the nickel site and is surrounded by aluminum neighbors. We
comment on the possible relation of this effect to the pesting degradation
phenomenon (essentially spontaneous disintegration in air) in nickel
aluminides.Comment: To appear in Phys. Rev. B (Aug. 15, 2001
A MATEMÁTICA DO PLANETA É A MATEMATINETA
Não se aplica
Active MR k-space Sampling with Reinforcement Learning
Deep learning approaches have recently shown great promise in accelerating
magnetic resonance image (MRI) acquisition. The majority of existing work have
focused on designing better reconstruction models given a pre-determined
acquisition trajectory, ignoring the question of trajectory optimization. In
this paper, we focus on learning acquisition trajectories given a fixed image
reconstruction model. We formulate the problem as a sequential decision process
and propose the use of reinforcement learning to solve it. Experiments on a
large scale public MRI dataset of knees show that our proposed models
significantly outperform the state-of-the-art in active MRI acquisition, over a
large range of acceleration factors.Comment: Presented at the 23rd International Conference on Medical Image
Computing and Computer Assisted Intervention, MICCAI 202
Cutoff value determines the performance of a semi-quantitative immunochemical faecal occult blood test in a colorectal cancer screening programme
BACKGROUND: The cutoff of semi-quantitative immunochemical faecal occult blood tests (iFOBTs) influences colonoscopy referrals and detection rates. We studied the performance of an iFOBT (OC-Sensor) in colorectal cancer (CRC) screening at different cutoffs. METHODS: Dutch screening participants, 50-75 years of age, with average CRC risk and an iFOBT value >or=50 ng ml(-1) were offered colonoscopy. The detection rate was the percentage of participants with CRC or advanced adenomas (>or=10 mm, >or=20% villous, high-grade dysplasia). The number needed to scope (NNTScope) was the number of colonoscopies to be carried out to find one person with CRC or advanced adenomas. RESULTS: iFOBT values >or=50 ng ml(-1) were detected in 526 of 6157 participants (8.5%) and 428 (81%) underwent colonoscopy. The detection rate for advanced lesions (28 CRC and 161 with advanced adenomas) was 3.1% (95% confidence interval: 2.6-3.5%) and the NNTScope was 2.3. At 75 ng ml(-1), the detection rate was 2.7%, the NNTScope was 2.0 and the CRC miss rate compared with 50 ng ml(-1) was <5% (N=1). At 100 ng ml(-1), the detection rate was 2.4% and the NNTScope was <2. Compared with 50 ng ml(-1), up to 200 ng ml(-1) CRC miss rates remained at 16% (N=4). CONCLUSIONS: Cutoffs below the standard 100 ng ml(-1) resulted in not only higher detection rates of advanced lesions but also more colonoscopies. With sufficient capacity, 75 ng ml(-1) might be advised; if not, up to 200 ng ml(-1) CRC miss rates are acceptable compared with the decrease in performed colonoscopies
CT colonography with minimal bowel preparation: evaluation of tagging quality, patient acceptance and diagnostic accuracy in two iodine-based preparation schemes
PURPOSE: The aim of this study was to compare a 1-day with a 2-day iodine bowel preparation for CT colonography in a positive faecal occult blood test (FOBT) screening population. MATERIALS AND METHODS: One hundred consecutive patients underwent CT colonography and colonoscopy with segmental unblinding. The first 50 patients (group 1) ingested 7 50 ml iodinated contrast starting 2 days before CT colonography. The latter 50 patients (group 2) ingested 4 50 ml iodinated contrast starting 1 day before CT colonography. Per colonic segment measurements of residual stool attenuation and homogeneity were performed, and a subjective evaluation of tagging quality (grade 1-5) was done. Independently, two reviewers performed polyp and carcinoma detection. RESULTS: The tagging density was 638 and 618 HU (p = 0.458) and homogeneity 91 and 86 HU for groups 1 and 2, respectively (p = 0.145). The tagging quality was graded 5 (excellent) in 90% of all segments in group 1 and 91% in group 2 (p = 0.749). Mean per-polyp sensitivity for lesions >or=10 mm was 86% in group 1 and 97% in group 2 (p = 0.355). Patient burden from diarrhoea significantly decreased for patients in group 2. CONCLUSIONS: One-day preparation with meglumine ioxithalamate results in an improved patient acceptability compared with 2-day preparation and has a comparable, excellent image quality and good diagnostic performanc
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