RESUMO
CNN-based salient object detection (SOD) methods achieve impressive performance. However, the way semantic information is encoded in them and whether they are category-agnostic is less explored. One major obstacle in studying these questions is the fact that SOD models are built on top of the ImageNet pre-trained backbones which may cause information leakage and feature redundancy. To remedy this, here we first propose an extremely light-weight holistic model tied to the SOD task that can be freed from classification backbones and trained from scratch, and then employ it to study the semantics of SOD models. With the holistic network and representation redundancy reduction by a novel dynamic weight decay scheme, our model has only 100K parameters, â¼ 0.2% of parameters of large models, and performs on par with SOTA on popular SOD benchmarks. Using CSNet, we find that a) SOD and classification methods use different mechanisms, b) SOD models are category insensitive, c) ImageNet pre-training is not necessary for SOD training, and d) SOD models require far fewer parameters than the classification models. The source code is publicly available at https://mmcheng.net/sod100k/.
Assuntos
Redes Neurais de Computação , Semântica , AlgoritmosRESUMO
BACKGROUND: Gender differences in valvular heart disease are increasingly recognised. A prior study has suggested better surgical outcomes in women with symptomatic aortic stenosis (AS). We investigate gender differences in medically managed severe AS. METHOD: We studied 347 patients with severe AS (aortic valve area index <0.6 cm2/m2) in terms of baseline clinical background, echocardiographic characteristics, and clinical outcomes. Appropriate univariate and multivariate models were employed, while Kaplan-Meier curves were constructed to compare mortality outcomes. RESULTS: In total, 205 (59%) patients were women. Despite higher incidences of hypertension (75.6% vs 47.3%) and diabetes mellitus (46.5% vs 29.5%) in women, women had improved survival (Kaplan-Meier log-rank = 6.24, p = 0.012). After adjusting for age (hazard ratio [HR], 1.034; 95% confidence interval [CI], 1.014-1.054), hypertension (HR, 1.469; 95% CI, 0.807-2.673), diabetes (HR, 1.219; 95% CI, 0.693-2.145), and indexed aortic valve area (HR 0.145, 95% CI 0.031-0.684) on multivariate analyses, female gender remained independently associated with lower mortality (HR, 0.561; 95%, CI 0.332-0.947). Women tended to have smaller body surface area (BSA), left ventricular (LV) internal diastolic diameter, and smaller LV outflow tract diameter but were similar to men in terms of LV ejection fraction, AS severity, and patterns of LV remodelling. CONCLUSIONS: Women appeared to have better outcomes compared to men in medically managed severe AS. These gender differences warrant further study and may affect prognosis, follow-up, and timing of valve surgery.
Assuntos
Estenose da Valva Aórtica/terapia , Valva Aórtica/cirurgia , Gerenciamento Clínico , Função Ventricular Esquerda/fisiologia , Idoso , Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/diagnóstico , Estenose da Valva Aórtica/epidemiologia , Diástole , Ecocardiografia , Feminino , Seguimentos , Humanos , Incidência , Masculino , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Fatores Sexuais , Singapura/epidemiologia , Volume Sistólico/fisiologia , Taxa de Sobrevida/tendênciasRESUMO
BACKGROUND/OBJECTIVES: Paradoxical low-flow aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) has only been described in severe AS. Controversy surrounds prognosis and management but no studies have reported this phenomenon in mild or moderate AS. We investigated the prevalence of flow and gradient patterns in this population, characterising their clinical and echocardiographic profile. METHODS: Consecutive subjects (n=1362) with isolated AS: mild (n=462, aortic valve area≥1.5cm(2), 2.5m/sAssuntos
Estenose da Valva Aórtica
, Valva Aórtica/fisiopatologia
, Hemodinâmica/fisiologia
, Volume Sistólico/fisiologia
, Remodelação Ventricular/fisiologia
, Fatores Etários
, Idoso
, Idoso de 80 Anos ou mais
, Estenose da Valva Aórtica/diagnóstico
, Estenose da Valva Aórtica/epidemiologia
, Estenose da Valva Aórtica/fisiopatologia
, Ecocardiografia Doppler em Cores/métodos
, Ecocardiografia Doppler em Cores/estatística & dados numéricos
, Feminino
, Humanos
, Masculino
, Prevalência
, Prognóstico
, Estudos Retrospectivos
, Índice de Gravidade de Doença
, Singapura/epidemiologia
Assuntos
Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/mortalidade , Índice de Gravidade de Doença , Idoso , Estudos de Coortes , Endocardite/diagnóstico , Endocardite/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Valor Preditivo dos Testes , Fatores de Risco , Fatores de TempoRESUMO
The present study examined the effects of anatase nanometer TiO2 on photochemical degradation of chlorothalonil in aqueous solution and on the plant surface. Results showed that nanometer TiO2 exhibited a strong photosensitizing effect on the degradation of chlorothalonil both in aqueous solution and on the surface of green pepper. The photosensitization rate was the highest in the sunlight compared to illumination under high-pressure mercury and UV lamps. Use of distinct hydroxyl radical scavengers indicated that nanometer TiO2 acted by producing hydroxyl radicals with strong oxidizing capacity. Notably, nanometer TiO2 facilitated complete photodegradation of chlorothalonil with no detectable accumulation of the intermediate chlorothalonil-4-hydroxy. Nanometer TiO2 was also active on the surface of green pepper under natural sunlight both inside and outside of plastic greenhouse. These results together suggest that nanometer TiO2 can be used as a photosensitizer to accelerate degradation of the pesticides under greenhouse conditions.
Assuntos
Capsicum/efeitos dos fármacos , Nanopartículas/química , Nitrilas/química , Praguicidas/química , Fármacos Fotossensibilizantes/química , Titânio/química , Poluentes Químicos da Água/química , Capsicum/química , Capsicum/normas , Luz , Nanopartículas/efeitos da radiação , Fotólise/efeitos da radiaçãoRESUMO
This paper introduces the development of the Free-MPR module, based on VC++6.0 environment and VTK5.0, and on Windows XP platform. The Free-MPR module can adjust freely the display plane according to the change of the visual angle, and implement the free multi-planar reformation.
Assuntos
Imageamento Tridimensional , Software , Tomografia Computadorizada por Raios X/métodos , Imagem EcoplanarRESUMO
OBJECTIVE: To investigate the morphological features of benign and malignant solitary pulmonary nodules (SPNs) and explore the radiological evidences for the differentiation of SPNs. METHODS: With SPN Dicom View software, we analyzed and compared images obtained from 23 patients with malignant SPNs and 22 patients with benign SPNs who received CT scanning with or without contrast medium injection. RESULTS: The enhancement in malignant SPNs group was significantly higher than in the benign SPNs group (P < 0.0001). The irregular enhancement in malignant SPNs group was significantly higher than in the benign SPNs group (P = 0. 0084). The mean range of enhancement was (45.04 +/- 26.76) HU in malignant SPNs group, which was significantly higher than that in the benign SPNs group [(15.70 +/- 17.84) HU, P = 0.033]. The mean peak enhancement value was (136.09 +/- 41.72) HU in malignant SPNs group, which was significantly higher than in benign SPNs group [ (60.60 +/- 60.27) HU, P = 0.007]. The mean enhancement area was (21.69 +/- 21.01)% in malignant SPNs group and (8.61 +/- 10.83)% in benign SPNs group (P = 0.203). CONCLUSION: The enhancement range and peak enhancement value as well as the morphologically irregular enhancement of SPNs may provide useful information in the clinical radiological diagnosis of SPNs.