534 research outputs found
High Dimensional Classification with combined Adaptive Sparse PLS and Logistic Regression
Motivation: The high dimensionality of genomic data calls for the development
of specific classification methodologies, especially to prevent over-optimistic
predictions. This challenge can be tackled by compression and variable
selection, which combined constitute a powerful framework for classification,
as well as data visualization and interpretation. However, current proposed
combinations lead to instable and non convergent methods due to inappropriate
computational frameworks. We hereby propose a stable and convergent approach
for classification in high dimensional based on sparse Partial Least Squares
(sparse PLS). Results: We start by proposing a new solution for the sparse PLS
problem that is based on proximal operators for the case of univariate
responses. Then we develop an adaptive version of the sparse PLS for
classification, which combines iterative optimization of logistic regression
and sparse PLS to ensure convergence and stability. Our results are confirmed
on synthetic and experimental data. In particular we show how crucial
convergence and stability can be when cross-validation is involved for
calibration purposes. Using gene expression data we explore the prediction of
breast cancer relapse. We also propose a multicategorial version of our method
on the prediction of cell-types based on single-cell expression data.
Availability: Our approach is implemented in the plsgenomics R-package.Comment: 9 pages, 3 figures, 4 tables + Supplementary Materials 8 pages, 3
figures, 10 table
Influence of the solar EUV flux on the Martian plasma environment
The interaction of the solar wind with the Martian atmosphere and ionosphere is investigated by using three-dimensional, global and multi-species hybrid simulations. In the present work we focus on the influence of the solar EUV flux on the Martian plasma environment by comparing simulations done for conditions representative of the extrema of the solar cycle. The dynamics of four ionic species (H<sup>+</sup>, He<sup>++</sup>, O<sup>+</sup>, O<sub>2</sub><sup>+</sup>), originating either from the solar wind or from the planetary plasma, is treated fully kinetically in the simulation model in order to characterize the distribution of each component of the plasma, both at solar maximum and at solar minimum. The solar EUV flux controls the ionization frequencies of the exospheric species, atomic hydrogen and oxygen, as well as the density, the temperature, and thus the extension of the exosphere. Ionization by photons and by electron impacts, and the main charge exchange reactions are self-consistently included in the simulation model. Simulation results are in reasonable agreement with the observations made by Phobos-2 and Mars Global Surveyor (MGS) spacecraft: 1) the interaction creates a cavity, void of solar wind ions (H<sup>+</sup>, He<sup>++</sup>), which depends weakly upon the phase of the solar cycle, 2) the motional electric field of the solar wind flow creates strong asymmetries in the Martian environment, 3) the spatial distribution of the different components of the planetary plasma depends strongly upon the phase of the solar cycle. The fluxes of the escaping planetary ions are computed from the simulated data and results for solar maximum are compared with estimates based on the measurements made by experiments ASPERA and TAUS on board Phobos-2
Avaliação da Influência de Implementos de Plantio Direto do Milho com Tomografia de Raios Gama.
bitstream/CNPDIA/10463/1/BPD10_2005.pd
Comparative bioavailability study of a test formulation (Lipless [ciprofibrate] - tablet - 100 mg; Biolab Sanus Pharmacy Ltda.) versus a reference formulation (Oroxadin [ciprofibrate] tablet - 100 mg, Sanofi-Aventis) in healthy volunteers of both sexes
Orientador: Gilberto de NucciTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: Método rápido, sensível e específico foi desenvolvido para quantificar ciprofibrato no plasma humano, utilizando bezafibrato como padrão interno (SI). O analito e o padrão interno foram extraídos do plasma, por extração líquido-líquido, usando um solvente orgânico (éter etílico/diclorometano 70/30 (v/v)). Os extratos foram analisados por cromatografia líquida de alta eficiência acoplada à espectrometria de massa (HPLC-MS/MS), do tipo eletrospray. A cromatografia foi realizada com coluna Gênesis C18 4?m analítica (4,6 x 150mm id) em fase móvel composta de acetonitrila/água (70/30, v/v) e 1 mM de ácido acético. O método teve um tempo de corrida cromatográfica de 2,7min e curva de calibração linear no intervalo de 0,1 - 60 ?g/mL (R2> 0,99). O limite de quantificação foi de 0,1?g/mL. Os valores de acurácia e precisão intra-corrida e inter-corrida foram inferiores a 13,5%. Os testes de estabilidade não indicaram degradação significativa. A recuperação do ciprofibrato foi de 81,2%, 73,3% e 76,2% para as concentrações de 0,3, 5,0 e 48,0 ?g/mL, respectivamente. Para o ciprofibrato, os parâmetros otimizados da energia declustering, energia de colisão e energia de saída foram -51 (V), -16 (eV) e -5 (V), respectivamente. O método também foi validado sem o uso do padrão interno. Este procedimento HPLC-MS/MS foi usado para avaliar a bioequivalência de duas formulações de comprimidos ciprofibrato 100mg, em voluntários sadios de ambos os sexos. Os seguintes parâmetros farmacocinéticos foram obtidos das curvas de concentração plasmática de cipofibrato versus tempo: ASCULTIMO, ASC0-168h, CMAX e TMAX. A média geométrica com intervalo de confiança correspondente a 90% (CI) para a razão de Teste / Referência foram: 93,80% (IC 90%= 88,16 - 99,79%) para CMAX, 98,31% (90% CI = 94,91-101,83%) para ASCULTIMO e 97,67% (90% CI = 94,45-101,01%) para ASC0-168h. Uma vez que o intervalo de confiança de 90% para a razão geométrica de CMAX , ASCÚLTIMO e ASC 0 -168h estavam dentro do intervalo de 80% -125% proposto pelo FDA dos EUA, concluiu-se que ciprofibrato (Lipless® 100mg comprimido) formulação fabricado pela Biolab Sanus Farmacêutica Ltda. é bioequivalente à formulação Oroxadin® (100mg comprimido) para a velocidade e a extensão da absorçãoAbstract: A rapid, sensitive and specific method for quantifying ciprofibrate in human plasma, using bezafibrate as the internal standard (IS) is described. The analyte and the IS were extracted from plasma, by liquid-liquid extraction using an organic solvent (diethyl ether / dichloromethane 70/30 (v/v)). The extracts were analyzed by high performance liquid chromatography coupled with electrospray tandem mass spectrometry (HPLC-MS/MS). Chromatography was performed using Genesis C18 4?m analytical column (4.6mm x 150mm i.d.) and a mobile phase consisting of acetonitrile/water (70/30, v/v) and 1mM acetic acid. The method had a chromatographic run time of 2.7 min and a linear calibration curve over the range 0.1-60 ?g/ml (R2>0.99). The limit of quantification was 0.1?g/ml. The intra and interday accuracy and precision values of the assay were less than 13.5%. The stability tests indicated no significant degradation. The recovery of ciprofibrate was 81.2%, 73.3% and 76.2% for the 0.3, 5.0 and 48.0?g/mL standard concentrations, respectively. For ciprofibrate, the optimized parameters of the declustering potential, collision energy and collision exit potential were -51 (V), -16 (eV) and -5 (V), respectively. The method was also validated without the use of the internal standard. This HPLC-MS/MS procedure was used to assess the bioequivalence of two ciprofibrate 100mg tablet formulations, in healthy volunteers of both sexes. The following pharmacokinetic parameters were obtained from the ciprofibrate plasma concentration vs. time curves: AUCLAST, AUC0-168h, CMAX and TMAX. The geometric mean with corresponding 90% confidence interval (CI) for Test/Reference percent ratios were 93.80% (90% CI= 88.16 - 99.79%) for CMAX, 98.31% (90% CI= 94.91 - 101.83%) for AUCLAST and 97.67% (90% CI= 94.45 - 101.01%) for AUC0-168h. Since the 90% CI for AUCLAST, AUC0-168h and CMAX ratios were within the 80-125% interval proposed by the US FDA, it was concluded that ciprofibrate (Lipless® 100 mg tablet) formulation manufactured by Biolab Sanus Farmacêutica Ltda. is bioequivalent to the Oroxadin® (100mg tablet) formulation for both the rate and the extent of absorptionDoutoradoClinica MedicaDoutora em Clínica Médic
Determinants of surgeon choice in cases of suspected implant rupture following mastectomy or aesthetic breast surgery: Clinical implications
Implant ruptures may be diagnosed by physical examination, ultrasound (US), and magnetic resonance imaging (MRI). The absence of standard guidelines to approach to implant ruptures may cause unnecessary surgical revisions in the absence of radiological confirmation of prosthetic damages.The purpose of this study was to analyze the diagnostic procedures applied to patients with suspected prosthetic rupture and surgeon choices to perform a revision or to plan a clinical and radiological follow-up.We conducted a retrospective study on 62 women submitted to revision surgery due to radiological diagnosis of suspected implant rupture, following mastectomy or aesthetic reconstruction, and admitted to a Plastic Surgery Department between 2008 and 2018.Seventy-three implants, believed to be ruptured, were explanted. One-third of these were intact and unnecessarily explanted. US associated with MRI evaluation resulted in the most helpful diagnostical method.A standardized clinical and radiological approach is essential to manage breast implant ruptures successfully. An innovative protocol is proposed in order to: ensure the appropriate management of implant ruptures and prevent unnecessary surgical revisions; reduce the risk of claims for medical malpractice in cases of unsatisfactory final aesthetic results or worse than before
Suppression of nitric oxide production in mouse macrophages by soybean flavonoids accumulated in response to nitroprusside and fungal elicitation
BACKGROUND: The anti-inflammatory properties of some flavonoids have been attributed to their ability to inhibit the production of NO by activated macrophages. Soybean cotyledons accumulate certain flavonoids following elicitation with an extract of the fungal pathogen Diaporthe phaseolorum f. sp. meridionalis (Dpm). Sodium nitroprusside (SNP), a nitric oxide donor, can substitute for Dpm in inducing flavonoid production. In this study, we investigated the effect of flavonoid-containing diffusates obtained from Dpm- and SNP-elicited soybean cotyledons on NO production by lipopolysaccharide (LPS)- and LPS plus interferon-γ (IFNγ)-activated murine macrophages. RESULTS: Significant inhibition of NO production, measured as nitrite formation, was observed when macrophages were activated in the presence of soybean diffusates from Dpm- or SNP-elicited cotyledons. This inhibition was dependent on the duration of exposure to the elicitor. Daidzein, genistein, luteolin and apigenin, the main flavonoids present in diffusates of elicited cotyledons, suppressed the NO production by LPS + IFNγ activated macrophages in a concentration-dependent manner, with IC(50 )values of 81.4 μM, 34.5 μM, 38.6 μM and 10.4 μM respectively. For macrophages activated with LPS alone, the IC(50 )values were 40.0 μM, 16.6 μM, 10.4 μM and 2.8 μM, respectively. Western blot analysis showed that iNOS expression was not affected by daidzein, was reduced by genistein, and was abolished by apigenin, luteolin and Dpm- and SNP-soybean diffusates at concentrations that significantly inhibited NO production by activated macrophages. CONCLUSIONS: These results suggest that the suppressive effect of flavonoids on iNOS expression could account for the potent inhibitory effect of Dpm- and SNP-diffusates on NO production by activated macrophages. Since the physiological concentration of flavonoids in plants is normally low, the treatment of soybean tissues with SNP may provide a simple method for substantially increasing the concentration of metabolites that are beneficial for the treatment of chronic inflammatory diseases associated with NO production
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