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1.
J Comput Assist Tomogr ; 48(3): 449-458, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38271541

RESUMO

OBJECTIVE: The aim of this study was to evaluate transfer learning combined with various convolutional neural networks (TL-CNNs) in predicting isocitrate dehydrogenase 1 ( IDH1 ) status of grade II/III gliomas. METHODS: Grade II/III glioma patients diagnosed at the Tangdu Hospital (August 2009 to May 2017) were retrospectively enrolled, including 54 patients with IDH1 mutant and 56 patients with wild-type IDH1 . Convolutional neural networks, AlexNet, GoogLeNet, ResNet, and VGGNet were fine-tuned with T2-weighted imaging (T2WI), fluid attenuation inversion recovery (FLAIR), and contrast-enhanced T1-weighted imaging (T1CE) images. The single-modal networks were integrated with averaged sigmoid probabilities, logistic regression, and support vector machine. FLAIR-T1CE-fusion (FC-fusion), T2WI-T1CE-fusion (TC-fusion), and FLAIR-T2WI-T1CE-fusion (FTC-fusion) were used for fine-tuning TL-CNNs. RESULTS: IDH1 -mutant prediction accuracies using AlexNet, GoogLeNet, ResNet, and VGGNet achieved 70.0% (AUC = 0.660), 65.0% (AUC = 0.600), 70.0% (AUC = 0.700), and 80.0% (AUC = 0.730) for T2WI images, 70.0% (AUC = 0.660), 70.0% (AUC = 0.620), 70.0% (AUC = 0.710), and 80.0% (AUC = 0.720) for FLAIR images, and 73.7% (AUC = 0.744), 73.7% (AUC = 0.656), 73.7% (AUC = 0.633), and 73.7% (AUC = 0.700) for T1CE images, respectively. The highest AUC (0.800) was achieved using VGGNet and FC-fusion images. CONCLUSIONS: TL-CNNs (especially VGGNet) had a potential predictive value for IDH1 -mutant status of grade II/III gliomas.


Assuntos
Neoplasias Encefálicas , Glioma , Isocitrato Desidrogenase , Imageamento por Ressonância Magnética , Gradação de Tumores , Humanos , Isocitrato Desidrogenase/genética , Glioma/diagnóstico por imagem , Glioma/genética , Feminino , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Masculino , Pessoa de Meia-Idade , Imageamento por Ressonância Magnética/métodos , Estudos Retrospectivos , Adulto , Idoso , Valor Preditivo dos Testes , Redes Neurais de Computação
2.
Front Neurosci ; 17: 1301778, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38125399

RESUMO

Background: Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM) are aging related diseases with high incidence. Because of the correlation of incidence rate and some possible mechanisms of comorbidity, the two diseases have been studied in combination by many researchers, and even some scholars call AD type 3 diabetes. But the relationship between the two is still controversial. Methods: This study used seed-based d mapping software to conduct a meta-analysis of the whole brain resting state functional magnetic resonance imaging (rs-fMRI) study, exploring the differences in amplitude low-frequency fluctuation (ALFF) and cerebral blood flow (CBF) between patients (AD or T2DM) and healthy controls (HCs), and searching for neuroimaging evidence that can explain the relationship between the two diseases. Results: The final study included 22 datasets of ALFF and 22 datasets of CBF. The results of T2DM group showed that ALFF increased in both cerebellum and left inferior temporal gyrus regions, but decreased in left middle occipital gyrus, right inferior occipital gyrus, and left anterior central gyrus regions. In the T2DM group, CBF increased in the right supplementary motor area, while decreased in the middle occipital gyrus and inferior parietal gyrus. The results of the AD group showed that the ALFF increased in the right cerebellum, right hippocampus, and right striatum, while decreased in the precuneus gyrus and right superior temporal gyrus. In the AD group, CBF in the anterior precuneus gyrus and inferior parietal gyrus decreased. Multimodal analysis within a disease showed that ALFF and CBF both decreased in the occipital lobe of the T2DM group and in the precuneus and parietal lobe of the AD group. In addition, there was a common decrease of CBF in the right middle occipital gyrus in both groups. Conclusion: Based on neuroimaging evidence, we believe that T2DM and AD are two diseases with their respective characteristics of central nervous activity and cerebral perfusion. The changes in CBF between the two diseases partially overlap, which is consistent with their respective clinical characteristics and also indicates a close relationship between them. Systematic review registration: PROSPERO [CRD42022370014].

3.
Carbohydr Polym ; 260: 117815, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33712159

RESUMO

Chitosan is a versatile polysaccharide in different domains due to facile modification and good biodegradability. In this paper, taking advantage of such functional properties, we have developed a stabilizer agent [OCMCS-SB] produced from chitosan, and palladium was successfully immobilized on this designed stabilizer [OCMCS-SB-Pd(II)]. The obtained complex was illuminated by 13C CP-MAS NMR, FT-IR, TGA, XRD, XPS, SEM, TEM and ICP-OES analyses. Due to the interactions of primary hydroxyl groups on chitosan, Schiff base and carboxy groups, the Pd complex showed excellent reactivity (up to 99 %) and stability towards Suzuki reactions in eco-friendly medium. Subsequently, the reusability experiments for OCMCS-SB-Pd(II) formed from chitosan were examined in five consecutive cycles, which showed no appreciable decrease in activity. Furthermore, a reasonably trifunctional complex structure was proposed. The present bio-based system offers a promising approach in utilizing such biopolymers in organic transformations.


Assuntos
Quitosana/química , Paládio/química , Catálise , Bases de Schiff/química , Espectroscopia de Infravermelho com Transformada de Fourier
4.
J Hazard Mater ; 414: 125543, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33677322

RESUMO

Cu-based SAPO-18, SAPO-18/34 intergrowth and SAPO-34 zeolites were applied for the selective catalytic reduction of NOx by ammonia (NH3-SCR) catalysts. Comprehensive characterization results revealed that the SAPO-18/34 with higher amount and strength of acid sites could facilitate the generation of more isolated copper ions (Cu2+ and Cu+) and suppress the formation of CuOx, which might account for the fact that intergrowth crystal structure of Cu-SAPO-18/34 exhibited higher fresh NH3-SCR activity, more robust hydrothermal durability and better SO2-resistance ability than that Cu-SAPO-18 and Cu-SAPO-34. In situ DRIFTS results provided the formation of reaction intermediates, such as -NH2, NH4+, NO3-, NO2-, etc. Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) reaction mechanisms were both involved in Cu-based SAPO-18 and SAPO-18/34 intergrowth zeolites, but the L-H mechanism dominated the NH3-SCR reaction, in addition, Cu-SAPO-34 only followed "L-H" mechanism.

5.
Chem Commun (Camb) ; 56(19): 2889-2892, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32037434

RESUMO

In this work, we report the first use of a salen-based hypercrosslinked polymer-supported Pd catalyst to carry out C-H halogenation. This catalyst can effectively catalyze C-H bromination and chlorination even better than its homogeneous counterpart Pd(OAc)2. It also showed excellent reusability without loss of catalytic activity for ten cycles. A broad substrate scope was explored and moderate to excellent yields were obtained.

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