Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nanotechnology ; 35(15)2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38176077

RESUMO

Aluminum-doped Ga2O3(AGO) thin films were prepared by plasma-enhanced atomic layer deposition (PE-ALD). The growth mechanism, surface morphology, chemical composition, and optical properties of AGO films were systematically investigated. The bandgap of AGO films can be theoretically set between 4.65 and 6.8 eV. Based on typical AGO films, metal-semiconductor-metal photodetectors (PDs) were created, and their photoelectric response was examined. The preliminary results show that PE-ALD grown AGO films have high quality and tunable bandgap, and AGO PDs possess superior characterizations to undoped films. The AGO realized using PE-ALD is expected to be an important route for the development of a new generation of gallium oxide-based photodetectors into the deep-ultraviolet.

2.
Nanotechnology ; 35(22)2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38387089

RESUMO

Low-cost, small-sized, and easy integrated high-performance photodetectors for photonics are still the bottleneck of photonic integrated circuits applications and have attracted increasing attention. The tunable narrow bandgap of two-dimensional (2D) layered molybdenum ditelluride (MoTe2) from ∼0.83 to ∼1.1 eV makes it one of the ideal candidates for near-infrared (NIR) photodetectors. Herein, we demonstrate an excellent waveguide-integrated NIR photodetector by transferring mechanically exfoliated 2D MoTe2onto a silicon nitride (Si3N4) waveguide. The photoconductive photodetector exhibits excellent responsivity (R), detectivity (D*), and external quantum efficiency at 1550 nm and 50 mV, which are 41.9 A W-1, 16.2 × 1010Jones, and 3360%, respectively. These optoelectronic performances are 10.2 times higher than those of the free-space device, revealing that the photoresponse of photodetectors can be enhanced due to the presence of waveguide. Moreover, the photodetector also exhibits competitive performances over a broad wavelength range from 800 to 1000 nm with a highRof 15.4 A W-1and a largeD* of 59.6 × 109Jones. Overall, these results provide an alternative and prospective strategy for high-performance on-chip broadband NIR photodetectors.

3.
Molecules ; 28(7)2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-37049664

RESUMO

Three new triterpenoids-spergulagenin B (1), spergulagenin C (2), and spergulagenin D (3)-were isolated from the aerial part of Glinus oppositifolius, along with 17 known compounds (4-20). The structures of these new compounds were identified by spectroscopic and MS analyses. Compounds 3, 5, 19, and 20 were evaluated for inhibition of nitric oxide production in LPS-stimulated RAW 264.7 cells with IC50 values of 17.03, 18.21, 16.30, and 12.64 µM, respectively. Compounds 3, 5, and 20 exhibited inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 cells with IC50 values of 18.35 ± 1.34, 17.56 ± 1.41, and 14.27 ± 1.29 µM, respectively.


Assuntos
Molluginaceae , Triterpenos , Animais , Camundongos , Molluginaceae/química , Triterpenos/farmacologia , Triterpenos/química , Óxido Nítrico , Lipopolissacarídeos/farmacologia , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Células RAW 264.7 , Estrutura Molecular
4.
BMC Med Inform Decis Mak ; 18(1): 135, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30563500

RESUMO

BACKGROUND: Hospitals have increasingly realized that wholesale adoption of electronic medical records (EMR) may introduce differential tangible/intangible benefits to them, including improved quality-of-care, reduced medical errors, reduced costs, and allowable instant access to relevant patient information by healthcare professionals without the limitations of time/space. However, an increased reliance on EMR has also led to a corresponding increase in the negative impact exerted via EMR breaches possibly leading to unexpected damage for both hospitals and patients. This study investigated the possible antecedents that will influence hospital employees' continuance compliance with privacy policy of Electronic Medical Records (EMR). This is done from both motivational and habitual perspectives; specifically, we investigated the mediating role of habit between motivation and continuance compliance intention with EMR privacy policy. METHODS: Data was collected from a large Taiwanese medical center by means of survey methodology. A total of 312 responses comprised of various groups of healthcare professionals was collected and analyzed via structural equation modeling. RESULTS: The results demonstrated that self-efficacy, perceived usefulness, and facilitating conditions may significantly predict hospital employees' compliance habit formation, whereas habit may significantly predict hospital employees' intention to continuance adherence to EMR privacy policy. Further, habit partially mediates the relationships between self-efficacy, perceived usefulness, facilitating conditions and continuance adherence intention. CONCLUSIONS: Based on our findings, the study suggests that healthcare facilities should take measures to promote their employees' habitualization with continuous efforts to protect EMR privacy parameters. Plausible strategies include improving employees' levels of self-efficacy, publicizing the effectiveness of on-going privacy policy, and creating a positive habit-conducive environment leading to continued compliance behaviors.


Assuntos
Atitude do Pessoal de Saúde , Registros Eletrônicos de Saúde , Fidelidade a Diretrizes , Recursos Humanos em Hospital , Privacidade , Adulto , Estudos Transversais , Feminino , Hábitos , Humanos , Masculino , Pessoa de Meia-Idade , Motivação , Autoeficácia , Taiwan
5.
Int J Mol Sci ; 19(7)2018 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-30037134

RESUMO

Non-alcoholic fatty liver disease (NAFLD) has become the most common liver disease in the recent decades in both developed and developing countries, and is predicted to be the major etiology for liver transplantation in the next decade. Thus, pharmacological strategies to treat NAFLD are urgently needed. Natural products are considered an excellent source for drug discovery. By utilizing an image-based high-throughput screening with a library containing 3000 Taiwanese indigenous plant extracts, we discovered that the extract of Syzygium simile leaves (SSLE) has an anti-lipid droplet (LD) accumulation effect in hepatic cell lines. Analyses of the expression profile of genes involved in lipid metabolism revealed that SSLE suppressed the mRNA expression of CD36, fatty acid translocase. In agreement with this observation, we showed that SSLE inhibited CD36 protein expression and fatty acid uptake and has only limited effects on pre-formed LDs. Moreover, SSLE reduced LD accumulation and CD36 expression in enterocyte and macrophage cell lines. In conclusion, our findings suggest that SSLE could serve as a potential source for the discovery of novel therapeutic modalities for NAFLD and that the suppression of CD36 expression and fatty acid uptake could contribute to the lipid-lowering effect of SSLE.


Assuntos
Ácidos Graxos/metabolismo , Extratos Vegetais/farmacologia , Folhas de Planta/química , Syzygium/química , Linhagem Celular Tumoral , Células Hep G2 , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos
6.
Molecules ; 22(3)2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-28294989

RESUMO

Myoporum bontioides is a traditional medicinal plant in Asia with various biological activities, including anti-inflammatory and anti-bacterial characteristics. To identify the bioactive constituents from M. bontioides, a newly-identified flavone, 3,4'-dimethoxy-3',5,7-trihydroxyflavone (compound 1), along with eight known compounds, were investigated in human MCF-7 breast cancer, SCC4 oral cancer, and THP-1 monocytic leukemia cells. Among these compounds, compound 1 exhibited the strongest antiproliferative activity with half-maximal inhibitory concentration (IC50) values ranging from 3.3 µM (MCF-7) to 8.6 µM (SCC4). Flow cytometric analysis indicated that compound 1 induced G2/M cell cycle arrest in MCF-7 cells. Mechanistic evidence suggests that the G2/M arrest could be attributable to compound 1's modulatory effects on the phosphorylation and expression of numerous key signaling effectors, including cell division cycle 2 (CDC2), CDC25C, and p53. Notably, compound 1 downregulated the expression of histone deacetylase 2 (HDAC2) and HDAC4, leading to increased histone H3 acetylation and p21 upregulation. Together, these findings suggest the translational potential of compound 1 as a breast cancer treatment.


Assuntos
Neoplasias da Mama/metabolismo , Flavonas/farmacologia , Pontos de Checagem da Fase M do Ciclo Celular , Myoporum/química , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Flavonas/química , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Transdução de Sinais/efeitos dos fármacos
7.
Nano Lett ; 14(2): 1026-31, 2014 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-24456092

RESUMO

DNA is a nanowire in nature which chelates Ni ions and forms a conducting chain in its base-pairs (Ni-DNA). Each Ni ion in Ni-DNA exhibits low (Ni(2+)) or high (Ni(3+)) oxidation state and can be switched sequentially by applying bias voltage with different polarities and writing times. The ratio of low and high oxidation states of Ni ions in Ni-DNA represents a programmable multistate memory system with an added capacitive component, in which multistate information can be written, read, and erased. This study also indicates that the biomolecule-based self-organized nanostructure can be used as a template for nanodevice fabrication.


Assuntos
DNA/química , Eletrodos , Nanopartículas Metálicas/química , Nanofios/química , Níquel/química , DNA/ultraestrutura , Condutividade Elétrica , Impedância Elétrica , Íons , Nanopartículas Metálicas/ultraestrutura , Nanofios/ultraestrutura , Oxirredução , Oxigênio/química
8.
J Ocul Pharmacol Ther ; 40(1): 100-107, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37851489

RESUMO

Background/Aims: The current standard of care to perform an anterior chamber paracentesis involves the use of a multipurpose market needle and syringe. The use of standard needles for this purpose may result in injury to the patient due to increased force with insertion and increased globe displacement during the procedure. This research investigates the current market needle characteristics and the impact of each needle characteristic on force. Methods: Several comparative trials were conducted to evaluate the needles. Needle characteristics of interest were gauge, primary bevel angle, number of bevels in the lancet, and needle hub geometry. Measurements of corneal insertion forces were made using a synthetic thermoplastic polyurethane medium, and bovine and porcine models. Needle safety was investigated with corneal abrasion experiments. Results: Reduced insertion force was observed with lower lancet primary angle. There was no difference based on the number of bevels in the lancet. Rounded hub geometry had minimal distribution to the corneal epithelium. Conclusions: Needle characteristics impact the force needed for needle insertion into the tissue. Since higher force can lead to increased risk and less efficiency during the procedure, reducing this force may improve the outcomes of the procedure. Needle entry can be reduced by designing an improved needle that includes a lower gauge and reduced primary angle of the lancet.


Assuntos
Agulhas , Paracentese , Animais , Bovinos , Humanos , Suínos , Paracentese/efeitos adversos , Modelos Animais , Câmara Anterior/cirurgia
9.
J Nat Prod ; 76(4): 489-94, 2013 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-23517145

RESUMO

Four new lanostanoids, ethyl lucidenate A (1), ethyl lucidenate F (2), 15-O-acetylganolucidate A (3), and 3,11,15,23-tetraoxo-27ξ-lanosta-8,16-dien-26-oic acid (4), and two new lactone derivatives, 5-hydroxy-5-(methoxymethyl)-4-methylfuran-2(5H)-one (5) and 3-(4-methoxy-2-oxo-2H-pyran-6-yl)propanoic acid (6), together with four known compounds, 11α-hydroxy-3,7-dioxolanost-8,24(E)-dien-26- oic acid (7), 3,7,11-trioxo-5α-lanosta-8,24(E)-dien-26-oic acid (8), methyl 3,7,11,12,15,23-hexaoxo-5α-lanost-8-en-26-oate (9), and ethyl 3,7,11,12,15,23-hexaoxo-5α-lanost-8-en-26-oate (10), were characterized from Antrodia camphorata. The structures of these new compounds were determined by analysis of their spectroscopic data, including 1D and 2D NMR experiments. Ten components were evaluated for anti-inflammatory activity by examining their effect on LPS-iNOS-dependent NO production in murine macrophage (RAW 264.7) cells. Among them, compounds 1, 3, 7, 8, 9, and 10 significantly suppressed the NO concentration in LPS-treated RAW 264.7 cells with IC50 values ≤ 10 µM.


Assuntos
Anti-Inflamatórios , Antrodia/química , Lanosterol , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Lanosterol/análogos & derivados , Lanosterol/química , Lanosterol/isolamento & purificação , Lanosterol/farmacologia , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Camundongos , Óxido Nítrico/biossíntese , Ressonância Magnética Nuclear Biomolecular , Estereoisomerismo , Taiwan
10.
Int J Mol Sci ; 14(3): 4629-39, 2013 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-23443162

RESUMO

Three new benzenoids, 3-isopropenyl-2-methoxy-6-methyl-4,5-methylenedioxy- phenol (1), 2-hydroxy-4,4'-dimethoxy-3,3'-dimethyl-5,6,5',6'-bimethylenedioxybiphenyl (2), 4,4'-dihydroxy-3,3'-dimethoxy-2,2'-dimethyl-5,6,5',6'-bimethylenedioxybiphenyl (3), together with two known benzenoids, 2,3,6-trimethoxy-5-methylphenol (4) and 2,3-methylenedioxy- 4-methoxy-5-methylphenol (5), were isolated from Antrodia camphorata. Our results support that compounds 1-5 potently inhibited LPS (lipopolysaccharide)-induced nitric oxide (NO) production in a dose-dependent manner. The IC(50) values of compounds 1, 3 and 5 were 1.8 ± 0.2, 18.8 ± 0.6 and 0.8 ± 0.3 µg/mL, respectively.

11.
Int J Mol Sci ; 14(6): 12581-92, 2013 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-23771024

RESUMO

Two new norsesquiterpenoids, solanerianones A and B (1-2), together with nine known compounds, including four sesquiterpenoids, (-)-solavetivone (3), (+)-anhydro-ß-rotunol (4), solafuranone (5), lycifuranone A (6); one alkaloid, N-trans-feruloyltyramine (7); one fatty acid, palmitic acid (8); one phenylalkanoid, acetovanillone (9), and two steroids, ß-sitosterol (10) and stigmasterol (11) were isolated from the n-hexane-soluble part of the roots of Solanum erianthum. Their structures were elucidated on the basis of physical and spectroscopic data analyses. The anti-inflammatory activity of these isolates was monitored by nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine macrophage RAW264.7 cells. The cytotoxicity towards human lung squamous carcinoma (CH27), human hepatocellular carcinoma (Hep 3B), human oral squamous carcinoma (HSC-3) and human melanoma (M21) cell lines was also screened by using an MTT assay. Of the compounds tested, 3 exhibited the strongest NO inhibition with the average maximum inhibition (Emax) at 100 µM and median inhibitory concentration (IC50) values of 98.23% ± 0.08% and 65.54 ± 0.18 µM, respectively. None of compounds (1-9) was found to possess cytotoxic activity against human cancer cell lines at concentrations up to 30 µM.


Assuntos
Anti-Inflamatórios/farmacologia , Raízes de Plantas/química , Solanum/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Concentração Inibidora 50 , Lipopolissacarídeos/farmacologia , Camundongos , Espectroscopia de Prótons por Ressonância Magnética
12.
Int J Mol Sci ; 14(5): 9168-81, 2013 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-23624606

RESUMO

Four new secondary metabolites, 3α-((E)-Dodec-1-enyl)-4ß-hydroxy-5ß-methyldihydrofuran-2-one (1), linderinol (6), 4'-O-methylkaempferol 3-O-α-L-(4''-E-p-coumaroyl)rhamnoside (11) and kaempferol 3-O-α-L-(4''-Z-p-coumaroyl)rhamnoside (12) with eleven known compounds-3-epilistenolide D1 (2), 3-epilistenolide D2 (3), (3Z,4α,5ß)-3-(dodec-11-ynylidene)-4-hydroxy-5-methylbutanolide (4), (3E,4ß,5ß)-3-(dodec-11-ynylidene)-4-hydroxy-5-methylbutanolide (5), matairesinol (7), syringaresinol (8), (+)-pinoresinol (9), salicifoliol (10), 4''-p-coumaroylafzelin (13), catechin (14) and epicatechin (15)-were first isolated from the aerial part of Lindera akoensis. Their structures were determined by detailed analysis of 1D- and 2D-NMR spectroscopic data. All of the compounds isolated from Lindera akoensis showed that in vitro anti-inflammatory activity decreases the LPS-stimulated production of nitric oxide (NO) in RAW 264.7 cell, with IC50 values of 4.1-413.8 µM.


Assuntos
Lindera/química , Lipopolissacarídeos/farmacologia , Macrófagos/metabolismo , Óxido Nítrico/biossíntese , Componentes Aéreos da Planta/química , Extratos Vegetais/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Macrófagos/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Camundongos , Extratos Vegetais/química
13.
Molecules ; 18(1): 682-9, 2013 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-23292330

RESUMO

Two new diterpenoids, konishone (1) and 3b-hydroxy-5,6-dehydrosugiol (2), along with three known diterpenoids--hinokiol (3), sugiol (4), and 12-hydroxy-6,7-secoabieta-8,11,13-triene-6,7-dial (5)--were isolated from the wood of Cunninghamia konishii. Compound 1 is a novel skeleton of the 7,20-dinorabietane-type diterpene. In addition, when RAW264.7 macrophages were treated with different concentrations of compounds 1, 3, and 5 together with LPS, a significant concentration-dependent inhibition of NO production was detected. The IC50 values for inhibition of nitrite production of compounds 1, 3, and 5 were about 9.8 ± 0.7, 7.9 ± 0.9, and 9.3 ± 1.3 µg/mL, respectively. This study presents the potential utilization of compounds 1, 3, and 5, as lead compounds for the development of anti-inflammatory drugs.


Assuntos
Anti-Inflamatórios/farmacologia , Cunninghamia/química , Diterpenos/farmacologia , Madeira/química , Animais , Anti-Inflamatórios/isolamento & purificação , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Diterpenos/isolamento & purificação , Avaliação Pré-Clínica de Medicamentos , Concentração Inibidora 50 , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Óxido Nítrico/metabolismo
14.
Research (Wash D C) ; 6: 0047, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37223466

RESUMO

Inorganic micro light-emitting diodes (micro-LEDs) based on III-V compound semiconductors have been widely studied for self-emissive displays. From chips to applications, integration technology plays an indispensable role in micro-LED displays. For example, large-scale display relies on the integration of discrete device dies to achieve extended micro-LED array, and full color display requires integration of red, green, and blue micro-LED units on the same substrate. Moreover, the integration with transistors or complementary metal-oxide-semiconductor circuits are necessary to control and drive the micro-LED display system. In this review article, we summarized the 3 main integration technologies for micro-LED displays, which are called transfer integration, bonding integration, and growth integration. An overview of the characteristics of these 3 integration technologies is presented, while various strategies and challenges of integrated micro-LED display system are discussed.

15.
Eur Rev Aging Phys Act ; 20(1): 22, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-38030985

RESUMO

BACKGROUND: Resistance training (RT) and nutritional supplementation are recommended for the management of sarcopenia in older adults. However, optimal RT intensity for the treatment of sarcopenia has not been well investigated. METHODS: This network meta-analysis aims to determine the comparative effectiveness of interventions for sarcopenia, taking RT intensity into consideration. RT intensity was classified into light-to-moderate intensity RT(LMRT), moderate intensity RT(MRT), and moderate-to-vigorous intensity RT(MVRT) based on percentage of one repetition maximum (%1RM) and/or rating of perceived exertion. RESULTS: A total of 50 RCTs (N = 4,085) were included after screening 3,485 articles. The results confirmed that RT with or without nutrition was positively associated with improved measures of muscle strength and physical performance. Regarding RT intensity, LMRT only demonstrated positive effects on hand grip (aerobic training + LMRT + nutrition: mean difference [MD] = 2.88; 95% credential intervals [CrI] = 0.43,5.32). MRT provided benefits on improvement in the 30-s chair stand test (repetitions) (MRT: MD = 2.98, 95% CrI = 0.35,5.59), timed up and go test (MRT: MD = -1.74, 95% CrI: = -3.34,-0.56), hand grip (MRT: MD = 2.44; 95% CrI = 0.03,5.70), and leg press (MRT: MD = 8.36; 95% CrI = 1.87,13.4). MVRT also improved chair stand test repetitions (MVRT: MD = 5.64, 95% CrI = 0.14,11.4), gait speed (MVRT + nutrition: MD = 0.21, 95% CrI = 0.003,0.48), appendicular skeletal muscle index (MVRT + nutrition: MD = 0.25, 95% CrI = 0.01,0.5), and leg press (MVRT: MD = 14.7, 95% CrI: 5.96,22.4; MVRT + nutrition: MD = 17.8, 95% CrI: 7.55,28.6). CONCLUSION: MVRT had greater benefits on muscle mass, lower extremity strength, and physical performance compared to MRT. Increasing RT intensity may be recommended for sarcopenic older adults.

16.
Nanotechnology ; 23(27): 275401, 2012 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-22706566

RESUMO

From first-principles approaches, we investigate the thermoelectric efficiency of a molecular junction where a benzene molecule is connected directly to the platinum electrodes. We calculate the thermoelectric figure of merit ZT in the presence of electron-vibration interactions with and without local heating under two scenarios: linear response and finite bias regimes. In the linear response regime, ZT saturates around the electrode temperature T(e) = 25 K in the elastic case, while in the inelastic case we observe a non-saturated and a much larger ZT beyond T(e) = 25 K attributed to the tail of the Fermi-Dirac distribution. In the finite bias regime, the inelastic effects reveal the signatures of the molecular vibrations in the low-temperature regime. The normal modes exhibiting structures in the inelastic profile are characterized by large components of atomic vibrations along the current density direction on top of each individual atom. In all cases, the inclusion of local heating leads to a higher wire temperature T(w) and thus magnifies further the influence of the electron-vibration interactions due to the increased number of local phonons.


Assuntos
Benzeno/efeitos da radiação , Microeletrodos , Modelos Químicos , Nanopartículas/química , Nanopartículas/efeitos da radiação , Simulação por Computador , Transporte de Elétrons , Elétrons , Temperatura Alta , Nanopartículas/ultraestrutura , Vibração
17.
Molecules ; 17(6): 6585-92, 2012 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-22728355

RESUMO

A new butanolide, 3ß-((E)-dodec-1-enyl)-4ß-hydroxy-5ß-methyldihydrofuran-2-one (1) and four known butanolides: Akolactone A (2), (3Z,4α,5ß)-3-(dodec-11-enylidene)-4-hydroxy-5-methylbutalactone (3), (3E,4α,5ß)-3-(dodec-11-enylidene)-4-hydroxy-5-methylbutalactone (4) and dihydroisoobtusilactone (5), were isolated from the aerial parts of Lindera akoensis. These butanolides showed in vitro anti-inflammatory activity decrease the LPS-stimulated production of nitrite in RAW264.7 cell, with IC50 values of 1.4-179.9 µM.


Assuntos
Anti-Inflamatórios/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Furanos/farmacologia , Lindera/química , Componentes Aéreos da Planta/química , Animais , Anti-Inflamatórios/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Medicamentos de Ervas Chinesas/química , Furanos/química , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Ressonância Magnética Nuclear Biomolecular
18.
ACS Appl Mater Interfaces ; 14(14): 16846-16855, 2022 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-35363489

RESUMO

The superior optical and electronic characteristics of quasi-two-dimensional ß-Ga2O3 make it suitable for solar-blind (200-280 nm) photodetectors (PDs). The metal-semiconductor-metal (MSM) PDs commonly suffer from low photoresponsivity, slow response speed, and a narrow detection wavelength range despite their simple fabrication process. Herein, we report a high-performance MSM PD by integrating exfoliated ß-Ga2O3 flakes with zero-dimensional graphene quantum dots (GQDs), which exhibits the advantages of enhancing the photoresponsivity, shortening the photoresponse time, and stimulating a broad range of photon detection. The hybrid GQDs/ß-Ga2O3 heterostructure PD is sensitive to deep-ultraviolet (DUV) light (250 nm) with an ultrahigh responsivity (R of ∼2.4 × 105 A/W), a large detectivity (D* of ∼4.3 × 1013 Jones), an excellent external quantum efficiency (EQE of ∼1.2 × 108%), and a fast photoresponse (150 ms), which is superior to the bare ß-Ga2O3 PD. These improvements result from effective charge transfer due to the introduction of GQDs, which enhance the light absorption and the generation of electron-hole pairs. In addition, the hybrid GQDs/ß-Ga2O3 PD also exhibits better photoelectric performance than the bare ß-Ga2O3 PD at a 1000 nm wavelength. As a conclusion, the hybrid GQDs/ß-Ga2O3 DUV photodetector shows potential applications in commercial optoelectronic products and provides an alternative solution for the design and preparation of high-performance photodetectors.

19.
Plants (Basel) ; 11(16)2022 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-36015447

RESUMO

Dianella ensifolia is a perennial herb with thickened rhizome and is widely distributed in tropical and subtropical regions of Asia, Australia, and the Pacific islands. This plant has the potential to be used as a source of herbal medicine. This study investigated further phytochemistry and tyrosinase inhibitory effect of some constituents isolated from D. ensifolia. Four new flavans, (2S)-4'-hydroxy-6,7-dimethoxyflavan (1), (2S)-3',4'-dihydroxy-7-methoxy-8-methylflavan (2), (2S)-2'-hydroxy-7-methoxyflavan (3), and (2S,1'S)-4-hydroxy-4-(7-methoxy-8-methylchroman-2-yl)-cyclohex-2-enone (4), together with 67 known compounds, including 10 flavans (5−14), 5 flavanones (15−19), 3 flavone (20−22), 5 chalcones (23−27), 3 chromones (28−30), 15 aromatics (31−45), 7 phenylpropanoids (46−52), one lignan (53), 7 steroids (54−60), one monoterpene (61), one diterpene (62), 4 triterpenes (63−66), a carotenoid (67), 2 alkaloids (68 and 69), and 2 fatty acids (70 and 71) were isolated from D. ensifolia. Their structures were elucidated on the basis of physical and spectroscopic data analyses. Moreover, compounds 1−4, 8, 10−15, 20, 21, and 41 were evaluated for their mushroom tyrosinase inhibitory effect. Compounds 11 and 14 strongly inhibited mushroom tyrosinase activity with IC50 values of 8.6 and 14.5 µM, respectively.

20.
Phytochemistry ; 204: 113347, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36027968

RESUMO

One undescribed C40 terpenoid, calomacroquinoic acid; four undescribed diterpenes, 5α,6α-epoxy-7α-hydroxyferruginol, 15-ethoxysugiol, 7-methoxy-6,7-secoabieta-8,11,13-triene-6,12-diol, and ethyl 7,8-secoabieta-11,14-dioxo-7-ate; two compounds isolated from Nature for the first time, 6ß,7α-dihydroxyferruginol and 12-O-methyltaxochinon; and six known compounds were successfully identified from the bark of Taiwan incense cedar Calocedrus formosana. Structures of all isolates were elucidated by physical data (appearance, ultraviolet, infrared, specific rotation, and X-ray) and spectroscopic data (1D and 2D nuclear magnetic resonance, and high-resolution electron ionization mass spectrometry). The biosynthetic pathway of calomacroquinoic acid is also described in the current study. Nitric oxide production in lipopolysaccharide (LPS)-stimulated BV-2 microglia cells was inhibited by 6,7-dehydroferruginol, 7α,11-dihydroxy-12-methoxy-8,11,13-abietriene, and trans-communic acid. Altogether, the bark of C. formosana possessed several potential natural therapeutics against inflammation-related neuronal diseases.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA