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1.
J Digit Imaging ; 35(3): 623-637, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35199257

RESUMO

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer worldwide, and it is characterized by the production of immature malignant cells in the bone marrow. Computer vision techniques provide automated analysis that can help specialists diagnose this disease. Microscopy image analysis is the most economical method for the initial screening of patients with ALL, but this task is subjective and time-consuming. In this study, we propose a hybrid model using a genetic algorithm (GA) and a residual convolutional neural network (CNN), ResNet-50V2, to predict ALL using microscopy images available in ALL-IDB dataset. However, accurate prediction requires suitable hyperparameters setup, and tuning these values manually still poses challenges. Hence, this paper uses GA to find the best hyperparameters that lead to the highest accuracy rate in the models. Also, we compare the performance of GA hyperparameter optimization with Random Search and Bayesian optimization methods. The results show that GA optimization improves the accuracy of the classifier, obtaining 98.46% in terms of accuracy. Additionally, our approach sheds new perspectives on identifying leukemia based on computer vision strategies, which could be an alternative for applications in a real-world scenario.


Assuntos
Redes Neurais de Computação , Leucemia-Linfoma Linfoblástico de Células Precursoras , Teorema de Bayes , Criança , Progressão da Doença , Humanos , Processamento de Imagem Assistida por Computador/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico
2.
J Crit Care ; 64: 165-172, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33906106

RESUMO

PURPOSE: To assess whether the combination of intra-abdominal hypertension (IAH, intra-abdominal pressure ≥ 12 mmHg) and hypoxic respiratory failure (HRF, PaO2/FiO2 ratio < 300 mmHg) in patients receiving invasive ventilation is an independent risk factor for 90- and 28-day mortality as well as ICU- and ventilation-free days. METHODS: Mechanically ventilated patients who had blood gas analyses performed and intra-abdominal pressure measured, were included from a prospective cohort. Subgroups were defined by the absence (Group 1) or the presence of either IAH (Group 2) or HRF (Group 3) or both (Group 4). Mixed-effects regression analysis was performed. RESULTS: Ninety-day mortality increased from 16% (Group 1, n = 50) to 30% (Group 2, n = 20) and 27% (Group 3, n = 100) to 49% (Group 4, n = 142), log-rank test p < 0.001. The combination of IAH and HRF was associated with increased 90- and 28-day mortality as well as with fewer ICU- and ventilation-free days. The association with 90-day mortality was no longer present after adjustment for independent variables. However, the association with 28-day mortality, ICU- and ventilation-free days persisted after adjusting for independent variables. CONCLUSIONS: In our sub-analysis, the combination of IAH and HRF was not independently associated with 90-day mortality but independently increased the odds of 28-day mortality, and reduced the number of ICU- and ventilation-free days.


Assuntos
Hipertensão Intra-Abdominal , Insuficiência Respiratória , Gasometria , Humanos , Hipertensão Intra-Abdominal/epidemiologia , Estudos Prospectivos , Fatores de Risco
3.
Gait Posture ; 24(2): 211-8, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16260141

RESUMO

This study compared the effects of a unilateral solid ankle-foot orthosis (AFO), hinged AFO and no AFO (shoe) worn by healthy adults on pelvic angles, lower extremity joint angles, moments and powers, and temporal-spatial gait characteristics during stair locomotion. A convenience sample of 19 healthy adults participated in this repeated measures design with subjects serving as their own controls. Subjects ambulated on stairs wearing a left shoe and either a right solid AFO, hinged AFO or shoe. Kinematic and kinetic data were collected with motion analysis equipment and a force plate for the three conditions. Pelvic angles and right hip, knee and ankle angles, moments and powers during stance were compared to determine differences among the conditions. Subjects wearing either orthosis walked slower during stair locomotion and with a shorter right single limb support time during descent. Sagittal knee and ankle angles, moments and powers were similar in individuals wearing a hinged AFO or shoe during pull-up (PU) in ascent and controlled lowering (CL) in descent. Decreased ankle dorsiflexion angle, plantar flexion power, knee flexion angle and extensor moment were seen in subjects wearing a solid AFO as compared to a hinged AFO during PU in ascent and CL in descent. Findings contributed to understanding how biomechanical changes imposed at the ankle by a unilateral solid AFO resulted in more kinetic and kinematic compensations than the hinged AFO in healthy adults without the confounding effects of neuromuscular impairments.


Assuntos
Locomoção/fisiologia , Aparelhos Ortopédicos , Adulto , Tornozelo , Fenômenos Biomecânicos , Desenho de Equipamento , Feminino , , Marcha/fisiologia , Humanos , Articulações/fisiologia , Extremidade Inferior/fisiologia , Masculino , Pelve/fisiologia
4.
Genet Mol Res ; 4(2): 390-408, 2005 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-16110453

RESUMO

In the struggle for life, the capacity of microorganisms to synthesize and secrete toxic compounds (inhibiting competitors) plays an important role in successful survival of these species. This ability must come together with the capability of being unaffected by these same compounds. Several mechanisms are thought to avoid the toxic effects. One of them is toxin extrusion from the intracellular environment to the outside vicinity, using special transmembrane proteins, referred to as transporters. These proteins are also important for other reasons, since most of them are involved in nutrient uptake and cellular excretion. In cancer cells and in pathogens, and particularly in fungi, some of these proteins have been pointed out as responsible for an important phenotype known as multidrug resistance (MDR). In the present study, we tried to identify in the Paracoccidioides brasiliensis transcriptome, transporter-ortholog genes from the two major classes: ATP binding cassette and major facilitator superfamily transporter. We found 22 groups with good similarity with other fungal ATP binding cassette transporters, and four Paracoccidioides brasilienses assembled expressed sequence tags that probably code for major facilitator superfamily proteins. We also focused on fungicide resistance orthologs already characterized in other pathogenic fungi. We were able to find homologs to C. albicans CDR1, CDR2, and MDR1, Saccharomyces cerevisiae PDR5 and Aspergillus AtrF genes, all of them related to azole resistance. As current treatment for paracoccidioidomycosis mainly uses azole derivatives, the presence of these genes can be postulated to play a similar role in P. brasiliensis, warning us for the possibility of resistant isolate emergence.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Antifúngicos/farmacologia , Farmacorresistência Fúngica Múltipla/genética , Etiquetas de Sequências Expressas/metabolismo , Paracoccidioides/efeitos dos fármacos , Transcrição Gênica , Transportadores de Cassetes de Ligação de ATP/efeitos dos fármacos , Transportadores de Cassetes de Ligação de ATP/metabolismo , Farmacorresistência Fúngica Múltipla/fisiologia , Humanos , Proteínas de Membrana Transportadoras/efeitos dos fármacos , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/fisiologia , Paracoccidioides/genética , Paracoccidioides/metabolismo
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