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1.
Comput Biol Med ; 168: 107758, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38042102

RESUMO

Convolutional neural network (CNN) has promoted the development of diagnosis technology of medical images. However, the performance of CNN is limited by insufficient feature information and inaccurate attention weight. Previous works have improved the accuracy and speed of CNN but ignored the uncertainty of the prediction, that is to say, uncertainty of CNN has not received enough attention. Therefore, it is still a great challenge for extracting effective features and uncertainty quantification of medical deep learning models In order to solve the above problems, this paper proposes a novel convolutional neural network model named DM-CNN, which mainly contains the four proposed sub-modules : dynamic multi-scale feature fusion module (DMFF), hierarchical dynamic uncertainty quantifies attention (HDUQ-Attention) and multi-scale fusion pooling method (MF Pooling) and multi-objective loss (MO loss). DMFF select different convolution kernels according to the feature maps at different levels, extract different-scale feature information, and make the feature information of each layer have stronger representation ability for information fusion HDUQ-Attention includes a tuning block that adjust the attention weight according to the different information of each layer, and a Monte-Carlo (MC) dropout structure for quantifying uncertainty MF Pooling is a pooling method designed for multi-scale models, which can speed up the calculation and prevent overfitting while retaining the main important information Because the number of parameters in the backbone part of DM-CNN is different from other modules, MO loss is proposed, which has a fast optimization speed and good classification effect DM-CNN conducts experiments on publicly available datasets in four areas of medicine (Dermatology, Histopathology, Respirology, Ophthalmology), achieving state-of-the-art classification performance on all datasets. DM-CNN can not only maintain excellent performance, but also solve the problem of quantification of uncertainty, which is a very important task for the medical field. The code is available: https://github.com/QIANXIN22/DM-CNN.


Assuntos
Medicina , Redes Neurais de Computação , Incerteza , Algoritmos , Método de Monte Carlo
2.
J Healthc Eng ; 2023: 4959130, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37342761

RESUMO

MRI is often influenced by many factors, and single image super-resolution (SISR) based on a neural network is an effective and cost-effective alternative technique for the high-resolution restoration of low-resolution images. However, deep neural networks can easily lead to overfitting and make the test results worse. The network with a shallow training network is difficult to fit quickly and cannot completely learn training samples. To solve the above problems, a new end-to-end super-resolution (SR) method is proposed for magnetic resonance (MR) images. Firstly, in order to better fuse features, a parameter-free chunking fusion block (PCFB) is proposed, which can divide the feature map into n branches by splitting channels to obtain parameter-free attention. Secondly, the proposed training strategy including perceptual loss, gradient loss, and L1 loss has significantly improved the accuracy of model fitting and prediction. Finally, the proposed model and training strategy take the super-resolution IXISR dataset (PD, T1, and T2) as an example to compare with the existing excellent methods and obtain advanced performance. A large number of experiments have proved that the proposed method performs better than the advanced methods in highly reliable measurement.


Assuntos
Aprendizagem , Memória , Humanos , Imageamento por Ressonância Magnética , Redes Neurais de Computação , Processamento de Imagem Assistida por Computador
3.
Comput Biol Med ; 152: 106353, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36473339

RESUMO

With the development of modern medical technology, medical image classification has played an important role in medical diagnosis and clinical practice. Medical image classification algorithms based on deep learning emerge in endlessly, and have achieved amazing results. However, most of these methods ignore the feature representation based on frequency domain, and only focus on spatial features. To solve this problem, we propose a hybrid domain feature learning (HDFL) module based on windowed fast Fourier convolution pyramid, which combines the global features with a wide range of receptive fields in frequency domain and the local features with multiple scales in spatial domain. In order to prevent frequency leakage, we construct a Windowed Fast Fourier Convolution (WFFC) structure based on Fast Fourier Convolution (FFC). In order to learn hybrid domain features, we combine ResNet, FPN, and attention mechanism to construct a hybrid domain feature learning module. In addition, a super-parametric optimization algorithm is constructed based on genetic algorithm for our classification model, so as to realize the automation of our super-parametric optimization. We evaluated the newly published medical image classification dataset MedMNIST, and the experimental results show that our method can effectively learning the hybrid domain feature information of frequency domain and spatial domain.


Assuntos
Algoritmos , Automação
4.
Food Chem Toxicol ; 129: 281-290, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31054997

RESUMO

(+)-Conocarpan (CNCP), a neolignan frequently found in many medicinal and edible plants displays a broad spectrum of bioactivity. Here, we demonstrated that CNCP induced apoptotic cell death in human kidney-2 (HK-2) cells in a concentration-dependent manner (IC50 = 19.3 µM) and led to the sustained elevation of intracellular Ca2+ ([Ca2+]i). Lower extracellular Ca2+ concentrations from 2.3 mM to 0 mM significantly suppressed the CNCP-induced Ca2+ response by 69.1%. Moreover, the depletion of intracellular Ca2+ stores using thapsigargin normalized CNCP-induced Ca2+ release from intracellular Ca2+ stores, suggesting that the CNCP-induced Ca2+ response involved both extracellular Ca2+ influx and Ca2+ release from intracellular Ca2+ stores. SAR7334, a TRPC3/6/7 channel inhibitor, but neither Pyr3, a selective TRPC3 channel inhibitor, nor Pico145, a TRPC1/4/5 inhibitor, suppressed the CNCP-induced Ca2+ response by 57.2% and decreased CNCP-induced cell death by 53.4%, suggesting a critical role for TRPC6 channels in CNCP-induced Ca2+ influx and apoptotic cell death. Further electrophysiological recording demonstrated that CNCP directly activated TRPC6 channels by increasing channel open probability with an EC50 value of 6.01 µM. Considered together, these data demonstrate that the direct activation of TRPC6 channels contributes to CNCP-induced apoptotic cell death in HK-2 cells. Our data point out the potential risk of renal toxicity from CNCP if used as a therapeutic agent.


Assuntos
Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Benzofuranos/toxicidade , Canal de Cátion TRPC6/fisiologia , Cálcio/metabolismo , Linhagem Celular , Humanos , Transporte de Íons
6.
Phytochemistry ; 150: 85-92, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29571149

RESUMO

Eight previously undescribed alkaloids, named corydemine, dihydrocorydemine, corydedine, 8,13-dioxo-14-hydroxytetrahydropalmatine, egenine-α-N-oxide, egenine-ß-N-oxide, 7'-O-ethylegenine-α-N-oxide, and 7'-O-ethylegenine-ß-N-oxide, together with three known ones, muramine, l-tetrahydropalmatine, and (+)-egenine, were isolated from the bulbs of Corydalis decumbens. Their structures were elucidated by comprehensive spectroscopic analysis and chemical correlation. The isolated compounds were tested for their ability to modulate neuronal excitability in primary cultured neocortical neurons. Four of the compounds, corydemine, dihydrocorydemine, muramine, and l-tetrahydropalmatine, inhibited neuronal excitability with IC50 values of 3.6, 16.7, 13.5 and 14.0 µM, respectively.


Assuntos
Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Corydalis/química , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Neurônios/química , Alcaloides/química , Animais , Alcaloides de Berberina , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/química , Camundongos , Estrutura Molecular , Neocórtex/citologia
7.
J Nat Prod ; 81(4): 913-917, 2018 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-29469570

RESUMO

Two new acylated ß-hydroxynitrile glycosides, ribemansides A (1) and B (2), were isolated from the aerial parts of Ribes manshuricum. Their structures were elucidated by comprehensive spectroscopic analysis. Ribemansides A and B inhibited transforming growth factor ß1 (TGF-ß1)-induced expression of α-smooth muscle actin, fibronectin release, and changes in cell morphology in the human proximal tubular epithelial cell line (human kidney-2, HK-2). Further biological evaluation demonstrated that both 1 and 2 inhibit the activity of canonical transient receptor potential cation channel 6 (TRPC6), with IC50 values of 24.5 and 25.6 µM, respectively. The antifibrogenic effect of these compounds appears to be mediated through TRPC6 inhibition, since the TRPC6 inhibitor, SAR7334, also suppressed TGF-ß1-induced fibrogenesis in HK-2 cells.


Assuntos
Glicosídeos/farmacologia , Extratos Vegetais/farmacologia , Ribes/química , Canal de Cátion TRPC6/antagonistas & inibidores , Fator de Crescimento Transformador beta1/metabolismo , Actinas/metabolismo , Células Cultivadas , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Fibronectinas/metabolismo , Glicosídeos/química , Humanos , Extratos Vegetais/química
8.
J Ethnopharmacol ; 178: 297-306, 2016 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-26481606

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Ribes diacanthum Pall. (Saxifragaceae), a Mongolian folk medicinal plant, was used to treat urinary system diseases. The present work aims to investigate the protective effects of Ribes diacanthum Pall (RDP) against cisplatin-induced nephrotoxicity. METHODS: The renal injury was modeled by intraperitoneal injection of cisplatin for 5 consecutive days (5 mg/kg). Nephroprotection of RDP was investigated by oral administration of RDP aqueous extract at a daily dose of 40 mg/kg for 14 consecutive days, starting 7 days prior to cisplatin administration. RESULTS: We demonstrated that pretreatment with RDP aqueous extract protected the mice from death induced by cisplatin administration. RDP treatment also significantly reduced blood urea nitrogen (BUN) and serum creatinine (Cr) levels observed in cisplatin-administrated mice. Histopathological analysis demonstrated that RDP administration protected cisplatin-induced renal tubular cell apoptosis. Further western blotting analysis revealed that RDP significantly reversed cisplatin-increased expression levels of cleaved-Caspase-3, Bax and cisplatin-decreased expression level of Bcl-2 in renal tissue. Finally, RDP markedly enhanced enzyme activities of reduced superoxide dismutase (SOD), Heme oxygenase 1 (HO-1) and catalase (CAT), suppressed lipid peroxidation as well as reactive oxygen species (ROS) production. CONCLUSION: We concluded that RDP displayed nephroprotective effects against cisplatin-induced renal tubular cell apoptosis, possibly associated with both enhanced antioxidase activity and suppressed ROS generation. Given the major nephrotoxicity of cisplatin cancer chemotherapy, RDP might be a potential candidate for neoadjuvant chemotherapy.


Assuntos
Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/tratamento farmacológico , Cisplatino/efeitos adversos , Rim/efeitos dos fármacos , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , Ribes/química , Injúria Renal Aguda/metabolismo , Animais , Apoptose/efeitos dos fármacos , Nitrogênio da Ureia Sanguínea , Caspase 3/metabolismo , Creatinina/sangue , Heme Oxigenase-1/metabolismo , Rim/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Extratos Vegetais/química , Plantas Medicinais/química , Substâncias Protetoras/química , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Proteína X Associada a bcl-2/metabolismo
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