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1.
Comput Med Imaging Graph ; 116: 102408, 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38908295

RESUMEN

Prostate Cancer is one of the most frequently occurring cancers in men, with a low survival rate if not early diagnosed. PI-RADS reading has a high false positive rate, thus increasing the diagnostic incurred costs and patient discomfort. Deep learning (DL) models achieve a high segmentation performance, although require a large model size and complexity. Also, DL models lack of feature interpretability and are perceived as "black-boxes" in the medical field. PCa-RadHop pipeline is proposed in this work, aiming to provide a more transparent feature extraction process using a linear model. It adopts the recently introduced Green Learning (GL) paradigm, which offers a small model size and low complexity. PCa-RadHop consists of two stages: Stage-1 extracts data-driven radiomics features from the bi-parametric Magnetic Resonance Imaging (bp-MRI) input and predicts an initial heatmap. To reduce the false positive rate, a subsequent stage-2 is introduced to refine the predictions by including more contextual information and radiomics features from each already detected Region of Interest (ROI). Experiments on the largest publicly available dataset, PI-CAI, show a competitive performance standing of the proposed method among other deep DL models, achieving an area under the curve (AUC) of 0.807 among a cohort of 1,000 patients. Moreover, PCa-RadHop maintains orders of magnitude smaller model size and complexity.

2.
RSC Adv ; 12(52): 33501-33509, 2022 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-36505724

RESUMEN

A family of microporous and robust Ln(iii)-based metal-organic frameworks (1-Ln, Ln = Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb) have been obtained using 4,4',4''-nitrilotribenzoic acid (H3NTB) in NMP-HCl solvent. Both single-crystal and powder X-ray diffraction analyses demonstrate that 1-Ln are isostructural and possess 3D frameworks with permanent porosity for Ar and CO2 adsorption. Strikingly, the incorporation of both Lewis acidic lanthanide ions and the basic triphenylamine group into 1-Ln makes them efficient acid-base catalysts for both cycloaddition of epoxides with CO2 and one-pot cascade deacetalization-Knoevenagel reactions. The systematic catalytic studies show that 1-Tb and 1-Yb possess the best catalytic activities for both reactions, indicating the catalytic activities of these Ln-MOFs are strongly dependent on metal Lewis acid sites embedded in the frameworks.

3.
Dalton Trans ; 50(47): 17785-17791, 2021 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-34821237

RESUMEN

A series of microporous Ln(III)-based metal-organic frameworks (1-Ln) have been hydrothermally synthesized using 4,4',4''-nitrilotribenzoic acid (H3NTB). Single crystal X-ray diffraction analyses show that 1-Ln are isostructural and have 3D porous frameworks with remarkable stability and permanent porosity for Ar and CO2 adsorption. In addition, 1-Ln exhibit diverse photoluminescence emissions depending on the nature of lanthanide ions. More importantly, 1-Ln are further studied in the Knoevenagel reactions of benzaldehyde derivatives and malononitrile under solvent-free conditions, and it is found that 1-Tb shows the best catalytic activities (yields up to 99%), providing a unique example to differentiate the roles of Ln ions within the frameworks in catalyzing Knoevenagel reactions.

4.
J Neurosci ; 22(3): 1098-107, 2002 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-11826138

RESUMEN

We investigated the effects of the central histaminergic system on afferent sensory signals in the retinogeniculocortical pathway in the intact brain. Extracellular physiological recordings in vivo were obtained from neurons in the cat dorsal lateral geniculate nucleus (LGN) in conjunction with electrical activation of the histamine-containing cells in the tuberomammillary nucleus of the hypothalamus. Tuberomammillary activation resulted in a rapid and significant increase in the amplitude of baseline activity and visual responses in LGN neurons. Geniculate X- and Y-cells were affected similarly. LGN cells that exhibited a burst pattern of activity in the control condition switched to a tonic firing pattern during tuberomammillary activation. Effects on visual response properties were assessed using drifting sinusoidal gratings of varied spatial frequency. The resultant spatial tuning curves were elevated by tuberomammillary activation, but there was no change in tuning curve shape. Rather, the effect was proportionate to the control response, with the greatest tuberomammillary effects at spatial frequencies already optimal for the cell. Tuberomammillary activation caused a small phase lag in the visual response that was similar at all spatial frequencies, consistent with the induced shift from burst to tonic firing mode. These results indicate a significant histaminergic effect on LGN thalamocortical cells, with no clear effect on thalamic inhibitory neurons. The histaminergic system appears to strengthen central transmission of afferent information, intensifying but not transforming the retinally derived signals. Promoting sensory input may be one way in which the histaminergic system plays a role in arousal.


Asunto(s)
Cuerpos Geniculados/fisiología , Histamina/metabolismo , Área Hipotalámica Lateral/metabolismo , Neuronas/fisiología , Vías Visuales/fisiología , Potenciales de Acción/fisiología , Animales , Nivel de Alerta/fisiología , Gatos , Estimulación Eléctrica , Femenino , Cuerpos Geniculados/citología , Masculino , Modelos Neurológicos , Inhibición Neural/fisiología , Distribución Normal , Estimulación Luminosa , Tiempo de Reacción/fisiología
5.
J Neurophysiol ; 95(1): 428-52, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16177177

RESUMEN

Synaptic activity was recorded with sharp microelectrodes during rest and during 0.3-Hz sinusoidal stimulation from bouton afferents identified by their efferent-mediated inhibitory responses. A glutamate antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) decreased quantal size (qsize) while lowering external Ca(2+) decreased quantal rate (qrate). Miniature excitatory postsynaptic potentials (mEPSPs) had effective durations (qdur) of 3.5-5 ms. Their timing was consistent with Poisson statistics. Mean qsizes ranged in different units from 0.25 to 0.73 mV and mean qrates from 200 to 1,500/s; there was an inverse relation across the afferent population between qrate and qsize. qsize distributions were consistent with the independent release of variable-sized quanta. Channel noise, measured during AMPA-induced depolarizations, was small compared with quantal noise. Excitatory responses were larger than inhibitory responses. Peak qrates, which could approach 3,000/s, led peak excitatory mechanical stimulation by 40 degrees . Quantal parameters varied with stimulation phase with qdur and qsize being maximal during inhibitory stimulation. Voltage modulation (vmod) was in phase with qrate and had a peak depolarization of 1.5-3 mV. On average, 80% of vmod was accounted for by quantal activity; the remaining 20% was a nonquantal component that persisted in the absence of quantal activity. The extracellular accumulation of glutamate and K(+) are potential sources of nonquantal transmission and may provide a basis for the inverse relation between qrate and qsize. Comparison of the phases of synaptic and spike activity suggests that both presynaptic and postsynaptic mechanisms contribute to variations across afferents in the timing of spikes during sinusoidal stimulation.


Asunto(s)
Vías Aferentes/fisiología , Células Ciliadas Vestibulares/fisiología , Neuronas Aferentes/fisiología , Terminales Presinápticos/fisiología , Transmisión Sináptica/fisiología , Tortugas/fisiología , Vestíbulo del Laberinto/fisiología , Potenciales de Acción/fisiología , Animales , Potenciales Postsinápticos Excitadores/fisiología
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