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1.
IEEE Trans Med Imaging ; 43(1): 542-557, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37713220

RESUMO

The early detection of glaucoma is essential in preventing visual impairment. Artificial intelligence (AI) can be used to analyze color fundus photographs (CFPs) in a cost-effective manner, making glaucoma screening more accessible. While AI models for glaucoma screening from CFPs have shown promising results in laboratory settings, their performance decreases significantly in real-world scenarios due to the presence of out-of-distribution and low-quality images. To address this issue, we propose the Artificial Intelligence for Robust Glaucoma Screening (AIROGS) challenge. This challenge includes a large dataset of around 113,000 images from about 60,000 patients and 500 different screening centers, and encourages the development of algorithms that are robust to ungradable and unexpected input data. We evaluated solutions from 14 teams in this paper and found that the best teams performed similarly to a set of 20 expert ophthalmologists and optometrists. The highest-scoring team achieved an area under the receiver operating characteristic curve of 0.99 (95% CI: 0.98-0.99) for detecting ungradable images on-the-fly. Additionally, many of the algorithms showed robust performance when tested on three other publicly available datasets. These results demonstrate the feasibility of robust AI-enabled glaucoma screening.


Assuntos
Inteligência Artificial , Glaucoma , Humanos , Glaucoma/diagnóstico por imagem , Fundo de Olho , Técnicas de Diagnóstico Oftalmológico , Algoritmos
2.
Nat Prod Res ; : 1-8, 2023 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-37574817

RESUMO

A new spiroterpenoid, namely tinctorin (1), along with one known compound, norreticulatin (2), were isolated from the lichen Parmotrema tinctorum (Despr. ex Nyl.) Hale. Their structures were elucidated by extensive spectroscopic analyses and electronic circular dichroism (ECD) calculations. The absolute configuration of 2 was established for the first time. Compound 1 was evaluated for its inhibitory activity against α-glucosidase and found to be inactive.

3.
MethodsX ; 9: 101655, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35330849

RESUMO

Modeling of diffusion/enzymatic reaction in porous electrodes operating in direct electron transfer mode is developed. The solution at the pore-scale is extremely cumbersome due to the complex geometry of the porous material. The upscaled model is much easier to solve, while keeping the essential of the physico-chemical behavior. The method to carry out the solution can be described as follows•The effective diffusion coefficient involved in the macroscopic equations is accurately computed by solving a closure problem in a representative elementary volume.•Electrochemical parameters are identified by a direct resolution of the macroscopic model solved with a COMSOL Multiphysics code coupled to a curve fit procedure carried out on voltammetry experimental results using a Matlab code. Electrodes with different thicknesses may be considered in the fitting procedure to improve accuracy. An alternative use of the COMSOL Multiphysics code is to predict the electrode behavior and further optimize its design, if all the electrochemical parameters are identified.•To validate the upscaled model, the pore scale model may be solved with direct numerical simulations carried out in a 3D microstructure using another COMSOL Multiphysics code to compare with the solution of the upscaled model in the 1D-reduced geometry.

4.
Heliyon ; 8(2): e08933, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35243058

RESUMO

For a long time, ethnic minorities in Ninh Thuan province have combined "Day Khai" (Coptosapelta flavescens Korth) with many other medicinal herbs, creating an esoteric remedy called "Cao Khai"-an aqueous extract from Day Khai. This study tested an aqueous extract from "Day Khai" for total phenolics, total flavonoids, antioxidant, and anti-inflammatory activity in an in vivo mice model. The aqueous extracts of raw materials C. flavescens collected in different regions were found to have phenolics, flavonoids, and antioxidant capacity in vitro according to DPPH, ABTS, RP, TAC, and FRAP methods. This study evaluated the effect of C. flavescens on arthritis of Complete Freund's adjuvant (CFA) induced-mice by observing changes in the degree of edema in the leg joints blood index and histology. The findings indicated that the "Cao Khai" had anti-inflammatory benefits and lowered the inflammatory symptoms in mice equivalent to Mobic medications (p < 0.05) while also limiting cartilage tissue damage after 14 days of usage. As a result, it is clear that "Cao Khai" can be considered a medicinal herb with tremendous potential for usage as an addition to illness therapy that should be protected and cultivated.

5.
Nat Prod Res ; 36(15): 3865-3871, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33656403

RESUMO

Two new phenolic compounds, cristiferides A-B (1-2) together with six known compounds, 2,4-dihydroxyphthalide (3), lecanoric acid (4), orsellinic acid (5), 5-chloroorsellinic acid (6), methyl haematommate (7), and methyl ß-orsellinate (8) were isolated from the lichen Parmotrema cristiferum (Taylor) Hale (Parmeliaceae). The structures of isolated compounds were identified from its spectroscopic data and by comparison with the literatures. Compounds 1-3 and 6-8 were evaluated for alpha-glucosidase inhibition. Compounds 2 and 7 revealed potent activity with IC50 values of 72.66 µM and 48.73 µM, respectively.


Assuntos
Líquens , Parmeliaceae , Líquens/química , Fenóis/química , Fenóis/farmacologia , Vietnã
6.
Nat Prod Res ; 35(7): 1167-1171, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31339381

RESUMO

Chemical investigation of the lichen Dirinaria applanata led to isolate nine compounds including a new hopane derivative, 1ß-acetoxy-21α-hopane-3ß,22-diol (1) together with six phenolic compounds naming divaricatinic acid (2), methyl divaricatinate (3), methyl-ß-orcinolcarboxylate (4), methyl haematommate (5), divarinol (6), ramalinic acid A (7), and two xanthones namely lichenxanthone (8), 4,5-dichlorolichenxanthone (9). Their structures were elucidated by spectroscopic data in combination with published literature. Except compound 2, all compounds were isolated from this species for the first time.


Assuntos
Ascomicetos/química , Triterpenos/isolamento & purificação , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Espectroscopia de Prótons por Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier , Estereoisomerismo , Triterpenos/química
7.
Polymers (Basel) ; 11(1)2019 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-30960161

RESUMO

In this study, chitosan nanoparticles were used as a carrier for Protocatechuic acid (PCA) to resist Pyricularia oryzae against rice blast. The final compound was characterized using zeta potentials for its surface electricity, Fourier transform infrared (FT-IR) analysis and transmission electron microscopy (TEM) were conducted for functional groups and for particle sizes and shape, respectively. The zeta potential results showed that loading PCA causes chitosan nanoparticle (CSNP) to decrease in surface electrons. The TEM images revealed that the particle size of chitosan (CS), although increasing in size when carrying PCA molecules, showed sufficient size for reasonable penetration into fungal cells. The FT-IR analysis showed that all functional group in CSNP carried PCA matched with previous studies. The antifungal test showed that diameters of inhibition zone of CS increases significantly after loading PCA, exhibiting the strongest antimicrobial effect on the Pyricularia oryzae fungus compared with weaker effects exhibited by CSNP alone or PCA. Our results suggested that CSNP loaded with PCA could be a potential compound for eradication of Pyricularia oryzae and that further testing on in vitro rice plants is recommended to reaffirm this possibility.

8.
BMJ Open ; 8(9): e020800, 2018 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-30181182

RESUMO

INTRODUCTION: Atrial fibrillation (AF) developing after cardiac surgery is the most common postoperative complication with an incidence up to 50%. The presence of postoperative AF is associated with significant morbidity, mortality and economic burden. However, in Vietnam, data on AF postcardiac surgery are limited, in part due to a shortage of screening equipment. This project aims to identify the incidence, risk factors and postoperative complications of new-onset postoperative AF after cardiac surgery, and the feasibility of introducing a novel screening strategy using the combination of two portable devices to detect AF. METHODS AND ANALYSIS: This is a feasibility study examining patients who are (1) ≥18 years old; (2) undergoing coronary artery bypass graft and/or valve surgery and (3) in normal sinus rhythm prior to their operation. Patients with congenital heart disease, a prior history of AF or those who require a pacemaker after surgery will be excluded. All patients will be followed up for the duration of their hospitalisation. The screening strategy will include monitoring the continuous ECG tracing in the intensive care unit, and if AF is suspected, a 30 s lead-1 ECG will be recorded using the smartphone-based AliveCor Kardia Mobile. On the postoperative wards, blood pressure will be measured three times daily using a modified blood pressure device (Microlife BP200 Afib): and if AF is suspected a 30 s ECG will be recorded using the AliveCor Kardia Mobile. A 12-lead ECG may be ordered subsequently if clinically indicated. The primary outcome is the incidence of postoperative AF. Secondary outcomes include establishing the risk factors and complications associated with postoperative AF; and the barriers and facilitators of the screening strategy. ETHICS AND DISSEMINATION: Ethics approval was granted by Scientific Board of Cardiovascular Centre, E Hospital on 28 September, 2017. Study results will be disseminated through local and international conferences and peer-reviewed publications.


Assuntos
Fibrilação Atrial/diagnóstico , Fibrilação Atrial/epidemiologia , Procedimentos Cirúrgicos Cardiovasculares/efeitos adversos , Países em Desenvolvimento , Programas de Rastreamento/métodos , Fibrilação Atrial/etiologia , Estudos de Viabilidade , Humanos , Incidência , Programas de Rastreamento/instrumentação , Projetos de Pesquisa , Vietnã/epidemiologia
9.
Nat Prod Res ; 31(19): 2281-2285, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28326853

RESUMO

For first time, the chemical constituents of the rhizomes of Luvunga scandens (Roxb.) Buch. Ham. were investigated and led to the isolation of one new limonoid named Luvunga A (1), together with seven known compounds, including one limonoid (2) and six coumarins (3-8) were isolated for the first time from the species L. scandens by various chromatography methods. Their chemical structures were elucidated by IR, UV, HR-ESI-MS, NMR 1D and 2D experiments and compared with literatures.


Assuntos
Limoninas/isolamento & purificação , Rizoma/química , Rutaceae/química , Cromatografia/métodos , Cumarínicos/isolamento & purificação , Limoninas/química , Análise Espectral
10.
Nat Prod Res ; 31(22): 2587-2592, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28135851

RESUMO

One new flavonol glycoside named visconoside C (1), together with seven known flavonol glycosides, quercetin 3-O-ß-d-glucopyranoside 7-O-α-l-rhamnopyranoside (2), quercetin 7-O-α-l-rhamnopyranoside (3), astragalin (4), kaempferol 3-O-(4-O-acetyl)-α-l-rhamnopyranoside (5), kaempferol 7-O-α-l-rhamnopyranoside (6), kaempferitrin (7) and kaempferol 3-O-ß-d-glucopyranoside 7-O-α-l-rhamnopyranoside (8) were isolated by various chromatography methods from the leaves of Cleome viscosa L. Their structures were elucidated by IR, UV, HR-ESI-MS and NMR (1D & 2D) experiments. The cytotoxicity and hepatoprotective activities using HepG2 human hepatoma cell line of 1 were measured by MTT assay. At the concentration of 25 µM and 50 µM, 1 showed cytotoxic activity against HepG2 cells (cell viability was decreased to 22.2 and 23.0%, respectively, compared with doxorubicin control), while at the concentration of 100 µM, 1 showed hepatoprotective activity against CCl4-induced hepatotoxicity on HepG2 cells (34.3%, compared with quercetin control).


Assuntos
Cleome/química , Flavonoides/farmacologia , Substâncias Protetoras/química , Substâncias Protetoras/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Flavonoides/química , Glicosídeos/química , Glicosídeos/farmacologia , Células Hep G2 , Humanos , Quempferóis/química , Quempferóis/isolamento & purificação , Quempferóis/farmacologia , Fígado/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Folhas de Planta/química , Espectrometria de Massas por Ionização por Electrospray , Vietnã
11.
Nat Prod Res ; 30(21): 2389-95, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27228410

RESUMO

From the fruit of Pandanus tectorius Parkinson ex Du Roi, one new dihydrofurocoumarin, named pandanusin A (1) and 15 known compounds, including one furanocoumarin (2), two coumarins (3, 4), four lignans (5-8), one neolignan (9), two flavonoids (10, 11), three phenolics (12-14), one monoglyceride (15) and one monosaccharide (16) were isolated by various chromatography methods. Among them, compounds (3-5) were obtained from the Pandanus genus for the first time and compounds (9-14, 16) were reported from this species for the first time. Their structures were elucidated by HR-ESI-MS, NMR 1D and 2D experiments and comparison with previous reported data. The α-glucosidase inhibitory activity of all compounds was measured. The isolated compounds (1-12, 14) showed better α-glucosidase inhibitory activity (IC50 = 42.2, 36.5, 84.7, 73.2, 40.8, 26.7, 76.5, 33.8, 68.1, 14.4, 22.1, 81.5, 43.8 µM, respectively) than the standard drug acarbose (IC50 = 214.5 µM).


Assuntos
Cumarínicos/isolamento & purificação , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Pandanaceae/química , Cumarínicos/química , Cumarínicos/farmacologia , Frutas/química , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia
12.
J Asian Nat Prod Res ; 18(6): 542-9, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26690849

RESUMO

From the leaves of Schefflera sessiliflora De P. V., two new triterpene saponins including one oleanane-type saponin, named scheffleraside C (1) and one lupane-type saponin scheffleraside D (2), together with six known triterpene saponins (3-8), were isolated by various chromatography methods. Among them, 3 was found for the first time from natural sources, while 6-8 were isolated for the first time from the genus Schefflera. Their structures were elucidated by IR, UV, HR-ESI-MS, NMR 1D and 2D experiments, and comparison of their NMR data with previously reported data. Their α-glucosidase inhibition and cytotoxic activity against MCF-7 human breast cancer cell lines were evaluated. The isolates (1, 3-5, 8) showed stronger α-glucosidase inhibitory activity (IC50 = 5.99-76.58 µM) than the standard drug acarbose (IC50 = 214.50 µM). At the concentration of 100 µg/ml, the isolates (1, 2) showed appreciable cytotoxic activity (67.92, 63.83%, respectively).


Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Araliaceae/química , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Inibidores de Glicosídeo Hidrolases/farmacologia , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/farmacologia , Saponinas/isolamento & purificação , Saponinas/farmacologia , Triterpenos/isolamento & purificação , Triterpenos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores de Glicosídeo Hidrolases/química , Humanos , Hipoglicemiantes/química , Concentração Inibidora 50 , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/química , Ácido Oleanólico/isolamento & purificação , Ácido Oleanólico/farmacologia , Folhas de Planta/química , Saponinas/química , Triterpenos/química
13.
Nat Prod Res ; 29(15): 1432-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25649464

RESUMO

From the leaves of Schefflera sessiliflora De P. V., one new C20-gibberellin diterpene 2ß,12ß-dihydroxygibberellin (12ß-hydroxy-GA110 or 2ß-hydroxy-GA112) (1), together with three known compounds, trans-tiliroside (2), kaempferol 3-O-ß-D-glucuronopyranoside (3), 5-p-trans-coumaroylquinic acid (4), was isolated for the first time from the genus Schefflera by various chromatography methods. Their structures were elucidated by IR, UV, HR-ESI-MS, NMR 1D and 2D experiments and comparison with previous reported data. The α-glucosidase inhibitory activity of all compounds was measured. The isolates (2, 3) showed better α-glucosidase inhibitory activity (IC50 = 134.60, 147.10 µM, respectively) than the standard drug acarbose (IC50 = 214.50 µM).


Assuntos
Araliaceae/química , Diterpenos/química , Giberelinas/química , Diterpenos/isolamento & purificação , Giberelinas/isolamento & purificação , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Estrutura Molecular , Folhas de Planta/química , Vietnã
14.
Nat Prod Res ; 29(15): 1437-41, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25674660

RESUMO

From the fruit of Pandanus tectorius Parkinson ex Du Roi, one new (1) and six known aldehyde compounds (2-7) were isolated by various chromatography methods. Based on their spectroscopic data, these compounds were identified as (Z)-4-hydroxy-3-(4-hydroxy-3-methylbut-2-en-1-yl) benzaldehyde (1), p-hydroxybenzaldehyde (2), syringaldehyde (3), (E)-ferulaldehyde (4), (E)-sinapinaldehyde (5), vanillin (6) and 5-hydroxymethylfurfual (7). The α-glucosidase inhibitory activity of all compounds was measured. The isolated compounds (1-6) showed better α-glucosidase inhibitory activity (IC50 values ranging from 36.5 to 192.4 µM) than the standard drug acarbose (IC50 = 214.5 µM).


Assuntos
Aldeídos/química , Benzaldeídos/química , Frutas/química , Pandanaceae/química , Aldeídos/isolamento & purificação , Benzaldeídos/isolamento & purificação , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Estrutura Molecular , Vietnã
15.
Nat Prod Res ; 29(2): 137-40, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25299239

RESUMO

Drynaria bonii H. Christ, a Vietnam traditional medicinal plant, is used for the treatment of osteoporosis, bone fractures, tinnitus, etc. (Ho PH. 2002. Vietnamese plants. Hanoi: Publisher of Young; Loi DT. 2004. Medicinal plants and remedy of Vietnam. Hanoi: Publisher of Medicine). Based on column chromatography, a new glucoside named drybonioside (5) and four known compounds α-tocopherol (1), 24-methylencycloartan-3ß-ol (2), triphyllol (3) and ethyl ß-D-fructopyranoside (4) were isolated and identified from hexane and methanol extracts of D. bonii. The structures of new compound were elucidated on the basis of NMR and MS spectroscopic analysis.


Assuntos
Glucosídeos/química , Polypodiaceae/química , Glucosídeos/isolamento & purificação , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Extratos Vegetais/química , Plantas Medicinais/química , Rizoma/química , Vietnã
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