4,979 research outputs found
Physical mechanisms of interface-mediated intervalley coupling in Si
The conduction band degeneracy in Si is detrimental to quantum computing
based on spin qubits, for which a nondegenerate ground orbital state is
desirable. This degeneracy is lifted at an interface with an insulator as the
spatially abrupt change in the conduction band minimum leads to intervalley
scattering. We present a theoretical study of the interface-induced valley
splitting in Si that provides simple criteria for optimal fabrication
parameters to maximize this splitting. Our work emphasizes the relevance of
different interface-related properties to the valley splitting.Comment: 4 pages, revised versio
Estratégias de controle de podridões em pós-colheita de melão: uma revisão
Aspectos gerais; Patologia pós-colheita de melão; Aspectos ecológicos e epidemiológicos das doenças em pós-colheita; Maturação de frutos x patologia pós-colheita de frutos; Considerações finais.bitstream/CNPAT-2010/10923/1/Dc-112.pd
Estratégias de controle de podridões em pós-colheita de melão: uma revisão.
Aspectos gerais; patologia pós-colheita de melão; aspectos ecológicos e epidemiológicos das doenças em pós-colheita; maturação de frutos x patologia pós-colheita; manejo integrado de doenças em pós-colheita de frutos.bitstream/CPATSA-2009-09/39310/1/OPB1947.pd
Evaluation of Bone Remodeling in Hemodialysis Patients: Serum Biochemistry, Circulating Cytokines and Bone Histomorphometry
BACKGROUND: To optimize the noninvasive evaluation of bone remodeling, we evaluated, besides routine serum markers, serum levels of several cytokines involved in bone turnover.
METHODS: A transiliac bone biopsy was performed in 47 hemodialysis patients. Serum levels of intact parathyroid hormone (iPTH; 1-84), total alkaline phosphatases (tAP), calcium, phosphate and aluminum (Al) were measured. Circulating levels of interleukin-6 (IL-6), IL-1 receptor antagonist (IL-1Ra) and soluble IL-6 receptor (sIL-6r) were determined using ELISA. Circulating IL-1beta, IL-6, IL-8, IL-10, IL-12p70 and tumor necrosis factor-alpha (TNF-alpha) were simultaneously quantified by flow cytometric immunoassay.
RESULTS: Patients with low/normal bone formation rate (L/N-BFR) had significantly lower serum iPTH (p300 pg/mL in association with tAP >120 U/L showed low sensitivity (58.8%) and low negative predictive value (44.0%) for the diagnosis of high BFR disease. An iPTH <300 pg/mL in association with normal or low tAP, <120 U/L, was associated with low sensitivity (66.7%) but high specificity (97.1%) for the diagnosis of L/N-BFR. Serum IL-1, IL-6, IL-12p70 and TNF-alpha were positively correlated with BFR, serum IL1-Ra and IL-10 with bone area, and by multiple regression analysis, tAP and IL-6 were independently predictive of BFR.
CONCLUSIONS: Significant associations were found between several circulating cytokines and bone histomorphometry in dialysis patients. The usefulness of these determinations in the noninvasive evaluation of bone remodeling needs to be confirmed in larger dialysis populations
Pré-termos abaixo das 27 semanas de idade gestacional: desfechos num hospital terciário.
Introduction: Over the last decades, survival of extremely preterm infants improved but there´s still significant morbidity among this group. We pretend to evaluate if specific attitudes/characteristics are associated with higher survival or survival without severe disabilities and elaborate predicting outcome models.
Material and Methods: Observational descriptive study, including the 205 liveborn/stillborn infants -gestational age 22w0d-26w6d- born at an Obstetrics Unit or transferred to a Neonatology Unit of a Level III Hospital, from January-2000 to December-2009. We collected variables related to management in the prenatal/neonatal period, neonate performances and psychomotor development (18-24 months). Significant associations between variables/outcomes were identified by chi-square test or t-test; multivariate logistic regression models were used to describe and predict mortality/morbidity.
Results: Advanced Gestational Age (GA) (p=0.001), antenatal corticotherapy(p=0.001), cesarean section(p=0.001), inborn delivery(p=0.021) and increased weight(p=0.001) were associated with survival. Absence of Intraventricular Hemorrhage (IVH) grade 3-4(p=0.001) and absence of Periventricular Leukomalacia (PVL) (p=0.005) were associated with survival without severe neurossensorial deficit. According to multivariable models, advanced GA (OR=0.353,CI95% 0.208-0.599), increased weight (OR=0.996,CI95% 0.993-0.999) and antenatal corticotherapy (OR=0.150,CI95% 0.044-0.510) were associated with lower mortality risk. Rupture of membranes less than 12 h duration was associated with higher mortality risk (OR=3.88,CI95% 1.406-10.680). IVH grades 3-4 was associated with higher morbidity risk (OR=16.931,CI95% 2.744-104.452). Mortality and severe morbidity models predicted correctly the outcome in 78.1% and 85.7% of the cases, respectively.
Conclusions: Mortality/morbidity models might be valuable tools providing insight in the prediction of the outcome of these neonates and helping parental counseling
Optimization of raw ewes’ milk high-pressure pre-treatment for improved production of raw milk cheese
Serra da Estrela protected designation of origin (PDO) cheese is manufactured with raw milk from Bordaleira and/or Churra Mondegueira da Serra da Estrela sheep breeds. Several socioenvironmental shortcomings have reduced production capacity; hence, treatments that may contribute to its efficient transformation into cheese are welcome. High-pressure processing (HPP) milk pre-treatment may contribute to a cheese yield increment, yet optimization of processing conditions is warranted. An initial wide-scope screening experiment allowed for pinpointing pressure intensity, holding time under pressure and time after HPP as the most important factors influencing curd yield. Based on this, a more targeted screening experiment allowed for selecting the range of experimental conditions to be used for an experimental design study that revealed an HPP treatment at 121 MPa for 30 min as the optimum for milk processing to improve curd yield (>9%) and effectively maintain the beneficial cheese microbiota; the optimum was validated in a final experimental framework.info:eu-repo/semantics/publishedVersio
Aclimatização de mudas micropropagadas de Bastão do Imperador em diferentes volumes de recipientes.
Aluminization of Scintillating Fibers for the Luminosity Detector of ATLAS
We report on tests on 25 cm long squared, 5mmx5mm SCF-3HF optical scintillating fibers, which have been aluminized by the magnetron sputtering technique in Lisbon during 2005. Two groups of fibers were used: 9 isolated fibers (Set I) and 20 stacked inside an acrylic piece (Set II). Fibers in Set I were used to measure the attenuation length of the fibers and were processed in Lisbon but not aluminized. Fibers in Set II were polished in a milling machine with a diamond blade and aluminium coated at one end. The other end was polished at CERN. From this set 10 were cut and polished at 90º with the axis of the fiber and the other 10 the end to be aluminized has been cut at 45º. The reflectivity of the aluminium mirror has been measured in a dedicated test bench. Preliminary results give a value of reflectivity of 51% for the fibers with a 90º cut
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