Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros

Base de dados
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Plant Physiol ; 193(4): 2442-2458, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37590971

RESUMO

Volatile esters in apple (Malus domestica) fruit are the critical aroma components determining apple flavor quality. While the exact molecular regulatory mechanism remains unknown, jasmonic acid (JA) plays a crucial role in stimulating the synthesis of ester aromas in apples. In our study, we investigated the effects of methyl jasmonate (MeJA) on the production of ester aroma in apples. MeJA treatment significantly increased ester aroma synthesis, accompanied by the upregulation of several genes involved in the jasmonate pathway transduction. Specifically, expression of the gene MdMYC2, which encodes a transcription factor associated with the jasmonate pathway, and the R2R3-MYB transcription factor gene MdMYB85 increased upon MeJA treatment. Furthermore, the essential gene ALCOHOL ACYLTRANSFERASE 1 (MdAAT1), encoding an enzyme responsible for ester aroma synthesis, showed increased expression levels as well. Our investigation revealed that MdMYC2 and MdMYB85 directly interacted with the promoter region of MdAAT1, thereby enhancing its transcriptional activity. In addition, MdMYC2 and MdMYB85 directly bind their promoters and activate transcription. Notably, the interaction between MdMYC2 and MdMYB85 proteins further amplified the regulatory effect of MdMYB85 on MdMYC2 and MdAAT1, as well as that of MdMYC2 on MdMYB85 and MdAAT1. Collectively, our findings elucidate the role of the gene module consisting of MdMYC2, MdMYB85, and MdAAT1 in mediating the effects of JA and promoting ester aroma synthesis in apples.


Assuntos
Malus , Malus/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Odorantes , Proteínas de Plantas/metabolismo , Ésteres/metabolismo , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas
2.
Opt Lett ; 49(14): 3974-3977, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39008754

RESUMO

Optofluidic techniques have evolved as a prospering strategy for microparticle manipulation via fluid. Unfortunately, there is still a lack of manipulation with simple preparation, easy operation, and multifunctional integration. In this Letter, we present an optofluidic device based on a graphite oxide (GO)-coated dual-fiber structure for multifunctional particle manipulation. By changing the optical power and the relative distance of the fibers, the system can excite thermal fluidic vortices with three inter-coupled states, namely uncoupled, partially coupled and completely coupled states, and therefore can realize capture, sorting, and transportation of the target particles. We conduct a numerical analysis of the whole system, and the results are consistent with the experimental phenomena. This versatile device can be utilized to manipulate target particles in complex microscopic material populations with the advantages of flexible operation, user-friendly control, and low cost.

3.
Opt Express ; 30(6): 9336-9347, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35299364

RESUMO

We investigate the propagation dynamics of elliptic Gaussian breathers without and with orbital angular momentum (OAM) in thermal nonlocal nonlinear media with both linear and nonlinear isotropy. The beamwidths and intensity of the elliptic breather without OAM, and the beamwidths and rotation angle of the elliptic breather with the critical OAM are analytically discussed in details. In experiment, the OAM-free elliptic beam is observed to oscillate and cannot form an elliptic soliton for any input power. By contrast, the elliptic beam carrying the critical OAM can keep its ellipticity changeless during the propagation and evolve into a spiralling elliptic soliton at the critical power. Specifically, in the vicinity of the critical power, the rotation angle of the spiralling elliptic beam can be controlled linearly by the input power and exceed π/2, while its beamwidths and ellipticity remain unchanged. Such a power-controllable, profile-preserving spiralling elliptic beam may provide potential applications in all-optical manipulation.

4.
Opt Express ; 30(25): 44864-44877, 2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36522900

RESUMO

To compensate for the inability for polarization imaging by conventional methods, metasurface optics with compactness and multi-function emerge as an approach to provide images with different linear and circular polarizations. Here, we propose a liquid crystal (LC) geometric phase-based chiral imaging lens (CIL) that simultaneously forms images of objects with opposite helicity. The CIL (Diameter 2.3 cm) was optimized by a spatial multiplexing algorithm and realized using the digital holography technique, where the LC domains were regulated by pixelated nanogratings with varied orientation. We investigated the potential of the patterning technique toward high order LC alignment by balancing the periodicity and depth of the nanogratings. The CIL exhibited a wide field of view of ±20°, which is attributed to the self- assembling effects of LC molecules. The compactness, lightness, and ability to produce chiral images of the LC CIL even at large angles have significant potential for practical polarization imaging.

5.
Opt Lett ; 47(11): 2674-2677, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35648902

RESUMO

Fluorescent sensors are resistant to electromagnetic interference and are electrically insulated, allowing for highly accurate measurements. Quantum dots (QDs) serve as outstanding sensing materials owing to the unique optical properties such as tunable photoluminescence (PL), excellent visible light activity, and high chemical and physical stability. In this paper, we develop an optical humidity sensor based on a QDs nanocomposite film. The film is made of polyvinyl alcohol (PVA), SiO2 microsphere (SM), and QDs through the layer-by-layer self-assembly method. The mechanism of humidity detection is moisture-induced quenching of the QDs fluorescence intensity. The results reveal that our sensor shows a good linear response to relative humidity in the range of 5% to 97%, a fast response-recovery time of 25 s and 20 s, and good repeatability for more than 50 cycles as well as high stability for over 180 days. Possessing the remarkable property, optical humidity sensors are envisaged for great potential applications in environmental monitoring.

6.
Opt Lett ; 47(8): 2028-2031, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35427328

RESUMO

Surface-enhanced Raman scattering (SERS) spectroscopy has attracted tremendous interest as a highly sensitive label-free tool to detect pollutants in aqueous environments. However, the high cost and poor reusability of conventional SERS substrates restrict their further applications in rapid and reproducible pollutant detection. Here, we report a reliable optical manipulation method to achieve rapid photothermal self-assembly of Au nanoparticles (AuNPs) in water within 30 s by a tapered optical fiber, which is utilized for highly sensitive SERS substrate preparation. The results show that the SERS substrate achieves low detection limits of 10-9 mol/L with an enhancement factor (EF) of 106 for chemical pollutants solutions, including thiram, pyrene, and rhodamine 6G. The SERS enhancement effect based on assembled AuNPs was more than 20 times that based on a gold colloid solution. As a result, the smart reversible assembly of AuNPs exhibits switchable plasmonic coupling for tuning SERS activity, which is promising for the application of SERS-based sensors and environmental pollutant detection.


Assuntos
Poluentes Ambientais , Nanopartículas Metálicas , Ouro/química , Nanopartículas Metálicas/química , Análise Espectral Raman/métodos
7.
Int J Mol Sci ; 23(7)2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35409122

RESUMO

Coloring in apple fruit due to anthocyanin accumulation is inhibited by high temperature; however, the underlying mechanism remains unclear. In the present study, total anthocyanin and cyanidin 3-galactoside contents were determined and compared between cv. 'Redchief Delicious' apple fruits at 25 °C and 35 °C treatments. The high temperature (35 °C) treatment substantially decreased total anthocyanin and cyanidin 3-galactoside contents. The transcriptomes of 25 °C- and 35 °C-treated apples were analyzed by high-throughput RNA sequencing. A total of 8354 differentially expressed genes (DEGs) were detected at four time points corresponding to the two temperature treatments. The up-regulated DEGs were annotated using GO as well as KEGG databases. A network module of 528 genes (including 21 transcription factors) most associated with the total anthocyanin and cyanidin 3-galactoside contents was constructed by weighted correlation network analysis (WGCNA). In the WGCNA module, we unearthed a LOB domain-containing gene designated as MdLBD37. The expression of MdLBD37 was sharply up-regulated by high temperature and negatively correlated with the total anthocyanin and cyanidin 3-galactoside contents. Overexpression of MdLBD37 in apple fruit and calli decreased the expression of anthocyanin biosynthetic genes, such as MdCHI, MdCHS, MdF3H, MdANS, MdDFR, and MdUFGT, along with anthocyanin accumulation. Our results suggested that MdLBD37 significantly influenced the high-temperature inhibition of anthocyanin accumulation in apples. The findings shed more light on the mechanism of anthocyanin inhibition during high-temperature stress in apples.


Assuntos
Malus , Antocianinas/metabolismo , Frutas/genética , Frutas/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Malus/genética , Malus/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Temperatura , Transcriptoma
8.
Opt Lett ; 46(12): 2807-2810, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34129545

RESUMO

We report the experimental observation of cylindrical-vector vortex solitons (CVVSs) in lead glass with strongly thermal nonlocal nonlinearity. The formations of radially and angularly polarized solitons with topological charge of $l = 1$ were observed. We show that the ring profiles and the polarization distributions of the two first-order CVVSs can be preserved. We numerically prove that the first-order CVVS is stable, and the higher-order CVVSs with $l \ge 2$ are unstable based on the linear stability analysis method.

9.
Opt Lett ; 46(15): 3629-3632, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34329242

RESUMO

Microfluidic techniques have emerged as promising strategies for a wide variety of synthetic or biological sorting. Unfortunately, there is still a lack of sorting with automatic and handy operation. In contrast to passively generated vortices, the thermocapillary vortices produced by temperature gradient have the advantages of flexible manipulation, stable strength, and simple integration. In this Letter, we present a device used for the pump-free separation of particles through vortices interaction without external fluidic control systems required for the majority of existing devices. Specifically, the device induces a different flow type upon the actuation of optical power, and the flow functions, such as simultaneous pumping and sorting, agree with stimulation results very well. More importantly, our developed sorting device can achieve separations by means of tunable cutoff diameter size. Therefore, this versatile device can be utilized to sort complex samples with the advantages of portability, user-friendly control, and automation.

10.
BMC Surg ; 21(1): 65, 2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33514359

RESUMO

BACKGROUND: Percutaneous vertebroplasty (PVP) and kyphoplasty (PKP) have been widely used to treat neurologically intact osteoporotic Kümmell's disease (KD), but it is still unclear which treatment is more advantageous. Our study aimed to compare and investigate the safety and clinical efficacy of PVP and PKP in the treatment of KD. METHODS: The relevant data that 64 patients of neurologically intact osteoporotic KD receiving PVP (30 patients) or PKP (34 patients) were analyzed. Surgical time, operation costs, intraoperative blood loss, volume of bone cement injection, and fluoroscopy times were compared. Occurrence of cement leakage, transient fever and re-fracture were recorded. Universal indicators of visual analogue scale (VAS) and Oswestry disability index (ODI) were evaluated separately before surgery and at 1 day, 6 months, 1 year, 2 years and the final follow-up after operation. The height of anterior edge of the affected vertebra and the Cobb's angle were assessed by imaging. RESULTS: All patients were followed up for at least 24 months. The volume of bone cement injection, intraoperative blood loss, occurrence of bone cement leakage, transient fever and re-fracture between two groups showed no significant difference. The surgical time, the operation cost and fluoroscopy times of the PKP group was significantly higher than that of the PVP group. The post-operative VAS, ODI scores, the height of the anterior edge of the injured vertebrae and kyphosis deformity were significantly improved in both groups compared with the pre-operation. The improvement of vertebral height and kyphosis deformity in PKP group was significantly better than that in the PVP group at every same time point during the follow-up periods, but the VAS and ODI scores between the two groups showed no significant difference. CONCLUSION: PVP and PKP can both significantly alleviate the pain of patients with KD and obtain good clinical efficacy and safety. By contrast, PKP can achieve better imaging height and kyphosis correction, while PVP has the advantages of shorter operation time, less radiation volume and operation cost.


Assuntos
Fraturas por Compressão/cirurgia , Cifoplastia/métodos , Fraturas por Osteoporose/cirurgia , Vertebroplastia/métodos , Idoso , Idoso de 80 Anos ou mais , Cimentos Ósseos , Feminino , Humanos , Masculino , Procedimentos Cirúrgicos Minimamente Invasivos , Estudos Retrospectivos , Fraturas da Coluna Vertebral/cirurgia , Resultado do Tratamento
11.
Opt Lett ; 44(12): 3098-3101, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31199390

RESUMO

We report, to the best of our knowledge, the first experimental observation of higher-charge vortex solitons and vector vortex solitons in lead glass with strongly thermal nonlocal nonlinearity. A higher-charge vortex soliton with a topological charge of l=4 and a vector vortex soliton consisting of two orthogonally polarized vortex components, with charges l1=1 and l2=4, were observed at several times of diffraction length. We show that the ring profiles and the carried topological charges of the two incoherently coupled vortex components can be preserved. We also numerically find that the stability of the higher-charge vortex can be enhanced by co-propagating a stable, single-charge vortex.

13.
J Asian Nat Prod Res ; 17(7): 717-23, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25559121

RESUMO

Two new capsaicin analogs, N-(3-methoxy-4-hydroxyphenethyl)-tetracosanamide (1) and N-(3,4-dihydroxyphenethyl)-tetracosanamide (2), along with one new flavonoidal glycoside pinnatifin E (3) were isolated from the ethanolic extract of the seeds of Vaccaria segetalis. Their structures were elucidated on the basis of spectroscopic methods including 1D, 2D NMR, MS, and other spectroscopic techniques, as well as by comparison with the relevant literatures. All compounds were evaluated for their coagulation Factor Xa inhibition activities.


Assuntos
Capsaicina/análogos & derivados , Capsaicina/isolamento & purificação , Medicamentos de Ervas Chinesas/isolamento & purificação , Flavonoides/isolamento & purificação , Glicosídeos/isolamento & purificação , Vaccaria/química , Capsaicina/química , Capsaicina/farmacologia , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Fator Xa/efeitos dos fármacos , Flavonoides/química , Flavonoides/farmacologia , Glicosídeos/análise , Glicosídeos/química , Glicosídeos/farmacologia , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Sementes/química
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 319: 124570, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38843616

RESUMO

Short-wave infrared emitting phosphors have extensive applications for spectroscopy technology. The near-infrared phosphor NaScP2O7:Cr3+ that we present in this work has a full width at half maximum (FWHM) of approximately 196 nm, which ranges from 700 to 1200 nm. To achieve efficient short-wave infrared, Yb3+ ions were co-doped. The NaScP2O7:Cr3+,Yb3+ material emitted infrared bands with peaks at 970 and 1003 nm upon excitation at450 nm. Benefitting from energy transfer (ET), the light in the 900-1200 nm from Yb3+ is effectively enhanced. Photoluminescence spectra, thermal quenching, and decay curves of Cr3+/Yb3+ single and codoped NaScP2O7 were investigated. An internal quantum yield of 29.6 % wasdemonstrated by the optimized phosphor NaScP2O7:Cr3+,Yb3+. Furthermore, The final fabrication of the short-wave infrared pc-LED was done through the combination of a blue-emitting chip and NaScP2O7:Cr3+,Yb3+ phosphor, thereby showing great promise for real implementations.

15.
Chemosphere ; 343: 140237, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37734501

RESUMO

Spinosad is a highly effective macrolide insecticide with a wide range of applications. However, few studies have been reported on the effects of Spinosad on immune cells. The immune system is an important line of defense in the human body and plays an important role in maintaining the normal functioning of the organism. Meanwhile, macrophages, neutrophils and Thymic T cells are an important component of the immune system. We studied the immunotoxicity of Spinosad using zebrafish and THP-1 cells. In vivo, Spinosad (0-20 µM) did not cause developmental toxicity in zebrafish, but induced damage to immune cells. In vitro, Spinosad (0-20 µM) inhibited THP-1 cells viability and induced mitochondrial damage and oxidative stress production. In further studies, it impaired phagocytosis of THP-1 cells and interfered with lipid metabolism. In addition, we found that Spinosad can promote the formation of the inflammatory body NLRP3 (NLR family, pyrin domain-containing 3) and activate the NF-kappa B (NF-κB) signaling pathway. These results suggest that Spinosad has a potential risk for inducing immunotoxicity. This study has drawn attention to Spinosad-induced immunotoxicity.

16.
Yao Xue Xue Bao ; 47(5): 630-3, 2012 May.
Artigo em Zh | MEDLINE | ID: mdl-22812008

RESUMO

The chemical shift of fluoxetine hydrochloride appears at delta 14.15 in 19F NMR analysis. The delta moved upfield slightly from 14.158 to 14.145 when the concentration of solution became diluted from 2.00 to 0.05 mmol x L(-1). Spiking test was suggested to confirm the existence of the compound for qualitative analysis. 19F NMR detection sensitivity test illustrated that a concentration of 17 mg in 1 L water could be detected while the sample was scanned 500 times with optimum parameters. In quantitative analysis, standard curve of concentration versus fluorine signal intensity was proposed to determine the amount of fluoxetine. Long capillary tube containing trifluoroacetic acid was used as internal standard for the integration measurements and straight line was obtained with good fitting. Direct additions of trifluoroethanol to fluoxetine solutions gave a poorer standard curve.


Assuntos
Fluoxetina/análise , Fluoxetina/química , Espectroscopia de Ressonância Magnética , Flúor/química , Estrutura Molecular , Ácido Trifluoracético/análise
17.
Hortic Res ; 9: uhac142, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36072842

RESUMO

Ethylene and jasmonic acid (JA) are crucial hormones that promote anthocyanin synthesis in apple (Malus × domestica). However, the mechanism by which these hormones cooperate to modulate anthocyanin production in apple is unclear. According to our results, MdERF1B expression was strongly induced by ethylene and JA. Physiological phenotypes and the results of molecular biological analyses indicated that MdERF1B encodes a positive regulator of anthocyanin synthesis. Specifically, MdERF1B was capable of combining directly with the MdMYC2 promoter to promote gene expression. Additionally, MdERF1B interacted with two JA signaling pathway inhibitors, namely MdJAZ5 and MdJAZ10. The MdERF1B-MdJAZ5/10 protein complex decreased the ability of MdERF1B to activate the MdMYC2 promoter. Furthermore, MdEIL1, which is a crucial protein for ethylene signal transduction, was observed to bind directly to the MdERF1B promoter, thereby upregulating gene expression. These results suggest that MdERF1B is a core gene responsive to JA and ethylene signals. The encoded protein, together with MdMYC2, MdJAZ5/10, and MdEIL1, modulates anthocyanin synthesis in apple. This study clarifies the synergistic mechanism by which JA and ethylene regulate anthocyanin production in apple.

18.
Hortic Res ; 2022 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-35184186

RESUMO

Ethylene regulates anthocyanin synthesis in ripening apple fruit via the antagonistic activities of the R2R3-MYB repressors and activators. However, the molecular mechanism underlying this process remains unknown. In this study, ethylene significantly induced the expression of the R2R3-MYB gene MdMYB17 in apple fruit. Moreover, MdMYB17 was revealed to be an important repressor of anthocyanin synthesis. Specifically, MdMYB17 binds directly to the promoters of the ethylene-induced genes MdMYB1 and MdEIL1, which encode positive regulators of anthocyanin synthesis, and represses their expression. Additionally, MdMYB1 and MdEIL1 bind to the MdMYB17 promoter to activate its expression. Thus, MdMYB17, MdMYB1, and MdEIL1 form a regulatory module that controls the expression of the corresponding genes. MdMYB17 interacts with MdEIL1. The interaction between MdMYB17 and MdEIL1 attenuates the regulatory effects of MdMYB17 on MdMYB1 and MdEIL1 as well as the regulatory effects of MdEIL1 on MdMYB17. Overall, our results reveal the molecular mechanisms by which MdMYB17, MdMYB1, and MdEIL1 finely mediate ethylene-regulated anthocyanin synthesis in apple fruit.

19.
Front Pharmacol ; 13: 794277, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35355711

RESUMO

Zanthoxylum nitidum (Roxb.) DC. (ZN), with strong effects of anti-inflammation and antioxidant activities is treated as a core herb in traditional Chinese medicine (TCM) preparation for treating stomachache, toothache, and rheumatoid arthritis. However, the active ingredients of ZN are not fully clarified due to its chemical complexity. In the present study, a double spectrum-effect analysis strategy was developed and applied to explore the bioactive components in herbs, and ZN was used as an example. Here, the chemical components in ZN were rapidly and comprehensively profiled based on the mass defect filtering-based structure classification (MDFSC) and diagnostic fragment-ion-based extension approaches. Furthermore, the fingerprints of 20 batches of ZN samples were analyzed by high-performance liquid chromatography, and the anti-inflammatory and antioxidant activities of the 20 batches of ZN samples were studied. Finally, the partial least squares regression (PLSR), gray relational analysis models, and Spearman's rank correlation coefficient (SRCC) were applied to discover the bioactive compounds in ZN. As a result, a total of 48 compounds were identified or tentatively characterized in ZN, including 35 alkaloids, seven coumarins, three phenolic acids, two flavonoids, and one lignan. The results achieved by three prediction models indicated that peaks 4, 12, and 17 were the potential anti-inflammatory compounds in ZN, whereas peaks 3, 5, 7, 12, and 13 were involved in the antioxidant activity. Among them, peaks 4, 5, 7, and 12 were identified as nitidine, chelerythrine, hesperidin, and oxynitidine by comparison with the standards and other references. The data in the current study achieved by double spectrum-effect analysis strategy had great importance to improve the quality standardization of ZN, and the method might be an efficiency tool for the discovery of active components in a complex system, such as TCMs.

20.
Opt Lett ; 36(21): 4194-6, 2011 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-22048362

RESUMO

A large phase shift of the strongly nonlocal spatial optical soliton (SNSOS) was predicted by Guo et al. [Phys. Rev. E69, 016602 (2004)]. We investigate the phase shift of the SNSOS in lead glass. It is found that the phase shift rate along the propagating direction of such a soliton is one order larger than that of the local soliton. The theory agrees quantitatively with the experiment on the dependence of the phase shift on the degree of nonlocality. We realize a π-phase shift by changing the optical power by about 10 mW around the critical soliton power, which agrees qualitatively with our theoretical result.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA