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1.
Plant Dis ; 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38386300

RESUMO

The genus Passiflora, commonly known as passion fruit, originated in South America, is an economically important horticulture crop and widely distributed in the tropics and subtropics. Yellow passion fruit (Passiflora edulis f. flavicarpa) and purple passion fruit (Passiflora edulis f. edulis) are the two most planted species (Santos-Jiménez et al., 2022), which have been largely cultivated in southern China. The average annual production reaches 600,000 tons, of which yellow fruit accounts for more than 70% (Zhou et al., 2022). In 2022 to 2023, a disease caused flower rot severely in passion fruit plantations. The incidence rate was generally 10% in purple passion fruit, with an incidence up to 60% in yellow passion fruit 'Qinmi No. 9'. Flower rot occurs mainly in the rainy season, especially during periods of prolonged rain. Infected flowers had black patches that were water-soaked on the interior of the flower bud. The patches covered the entire flower bud, and fluffy mycelium and sporangia developed, which caused the flower bud rotten and abscised easily. Five symptomatic flowers from Wuhua, Guangdong (23°23'N, 115°18'E) and 8 symptomatic flowers from Shangsi, Guangxi (21°15'N, 107°98'E) of 'Qinmi No. 9' were collected during flowering period in 2022 and 2023. Diseased flower pieces were surface-sterilized with 70% ethanol for 2 to 3 min, rinsed with sterile distilled water 3 times, and placed on PDA medium at 25℃ in darkness. Four and 6 fungal isolates with similar morphology were isolated from the infected samples of Wuhua and Shangsi, respectively. Two isolates, PRFJ01 from Wuhua and PRGX02 from Shangsi, were randomly selected for further study. Purified fungal colonies at the age of 3 days accompany with diffuse cottony mycelia, turned white to gray later. The mycelia were hyaline and aseptate. Sporangiophores with 0.56 (0.22~1.10) mm in length and 6.1 (3.18~10.87) µm in width (n=100) were erect, light brown, and had rhizoids and stolons at their bases. Sporangia with 48.0 (23.45~92.85) µm in diameter (n=100) were dark-colored, near spherical and having dark ovoid sporangiospores with 3.56 (2.34~6.39) µm × 2.82 (1.73~4.70) µm (n=100). The morphology of the fungus were identical to Rhizopus stolonifer (Ehrenb.) Vuill (Haque et al. 2023). The two isolates were molecularly identified using genomic regions of 28S large ribosomal subunit (LSU) with NL1 and LR3 primers (Cruz-Lachica et al., 2018). The phylogenetic trees revealed the sequences of PRFJ01 (OR801560.1) and PRGX02 (OR801561.1) were 100% and 99% identical to R. stolonifer (MK705761.1 and KC412868.1), respectively. Pathogenicity tests were conducted on healthy flowers and leaves of 5-month-old grafted 'Qinmi No. 9' plants. Mycelial plugs with 5-mm diameter were placed on the flowers and leaves. Three plants were performed for each of the isolates, and the test was repeated twice. The inoculated plants were moisturized with plastic bags. Healthy flowers and leaves inoculated with sterile PDA plugs were used as control. Typical symptoms were observed on inoculated plants after 2 days. The dark grey mycelia and sporangia covered the entire flower after 4 days inoculation. The flower bud became putrid and the flower stalk split off. Lesions on leaves expanded accompany with numerous aerial mycelium. However, the controls were symptomless. R. stolonifer was reisolated from inoculated tissues. Previously, flower rot on passion fruit caused by R. stolonifer has only been recorded in Brazil (Ploetz, 2003). To our knowledge, this is the first report of R. stolonifer causing flower rot on passion fruit in China.

2.
Angew Chem Int Ed Engl ; 63(24): e202405310, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38606567

RESUMO

Chiral hybrid metal halides hold great potential as circularly polarized luminescence light sources. Herein, we have obtained two enantiomeric pairs of one-dimensional hybrid chiral manganese(II) chloride single crystals, R/S-(3-methyl piperidine)MnCl3 (R/S-1) and R/S-(3-hydroxy piperidine)MnCl3 (R/S-2), crystallizing in the non-centrosymmetric space group P212121. In comparison to R/S-1, R/S-2 single crystals not only show red emission with near-unity photoluminescence quantum yield (PLQY) and high resistance to thermal quenching but also exhibit circularly polarized luminescence with an asymmetry factor (glum) of 2.5×10-3, which can be attributed to the enhanced crystal rigidity resulting from the hydrogen bonding networks between R/S-(3-hydroxy piperidine) cations and [MnCl6]4- chains. The circularly polarized luminescence activities originate from the asymmetric [MnCl6]4- luminophores induced by N-H⋅⋅⋅Cl hydrogen bonding with R/S-(3-hydroxy piperidine). Moreover, these samples demonstrate great application potential in circularly polarized light-emitting diodes and X-ray scintillators. This work shows a highly efficient photoluminescent Mn-based halide and offers a strategy for designing multifunctional chiral metal halides.

3.
BMC Cancer ; 21(1): 1196, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34758762

RESUMO

Aurora A kinase is a cell cycle regulator that is dysregulated in several different malignancies. Nevertheless, its regulatory mechanisms are still not fully understood. Here, we report that ubiquitin specific peptidase 3 (USP3) promotes proliferation and metastasis of esophageal squamous cell carcinoma (ESCC) cells by mediating deubiquitination of Aurora A. Analysis of human clinical samples indicated that USP3 and Aurora A are highly expressed in ESCC. Cellular experiments confirmed that high expression of USP3 and Aurora A in ESCC cells promoted malignant cell proliferation and invasion. In this mechanism, USP3 leads to suppression of Aurora A ubiquitination, resulting less proteasome degradation. We constructed the deubiquitinated mimetic K143R of Aurora A and found that K143R significantly promoted the proliferation and invasion of ESCC cells and was not regulated by the deubiquitination of USP3. Moreover, Aurora A K143R potentiated the kinase activity of Aurora A in ESCC cells. Thus, our findings demonstrate that the tumorigenic feature of ESCC is in part mediated by USP3-facilitated deubiquitination of Aurora A.


Assuntos
Aurora Quinase A/metabolismo , Neoplasias Esofágicas/genética , Carcinoma de Células Escamosas do Esôfago/genética , Regulação Neoplásica da Expressão Gênica , Proteases Específicas de Ubiquitina/metabolismo , Carcinogênese/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/patologia , Humanos , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Ubiquitinação
4.
J Chem Phys ; 155(23): 234701, 2021 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-34937354

RESUMO

In this work, we demonstrated an in situ approach for doping CsPbBr3 nanocrystals (NCs) with In3+ and Cl- with a ligand-assisted precipitation method at room temperature. The In3+ and Cl- co-doped NCs are characterized by the powder x-ray diffraction patterns, ultraviolet-visible, photoluminescence (PL) spectroscopy, time-resolved PL (TRPL), ultraviolet photoelectron spectroscopy, x-ray photoelectron spectroscopy, and transmission electron microscopy. Based on PL and TRPL results, the non-radiative nature of In3+-doping induced localized impurity states is revealed. Furthermore, the impact of In3+ and Cl- doping on charge transfer (CT) from the NCs to molecular acceptors was investigated and the results indicate that the CT at the interface of NCs can be tuned and promoted by In3+ and Cl- co-doping. This enhanced CT is attributed to the enlarged energy difference between relevant states of the molecular acceptor and the NCs by In3+ and Cl- upon co-doping. This work provides insight into how to control interfacial CT in perovskite NCs, which is important for optoelectronic applications.

5.
J Chem Phys ; 152(3): 034701, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31968978

RESUMO

Methylammonium lead bromide (MAPbBr3) perovskite quantum dots (PQDs) passivated with capping ligands with different chain length, including butylamine-valeric acid (BUTY-VA), octylamine-caprylic acid (OCTY-CA), and dodecylamine-lauric acid (DODE-LA), are investigated to determine an optimized capping layer thickness for maximizing both electronic and antimoisture properties of perovskite materials in optoelectronic devices. The photoluminescence quantum yield (PLQY) is observed to be chain length dependent, where the PLQY of BUTY-VA, OCTY-CA, and DODE-LA MAPbBr3 PQDs is 82% ± 4%, 68% ± 7%, and 18% ± 2%, respectively. Electrochemical impedance spectroscopy (EIS) measurements of each PQD film reveal that there is a slight increase in conductivity from reducing the capping ligand chain length from 8 carbon atoms (OCTY-CA) to 4 carbon atoms (BUTY-VA). Using the Butler-Volmer equation, the charge transfer factor ß for BUTY-VA and OCTY-CA MAPbBr3 PQD films in a tetrabutylammonium hexafluorophosphate-dichloromethane electrolyte solution was calculated to be 0.36 and 0.31, respectively. From an Arrhenius analysis, the activation energy (Ea) for charge transport between the PQD film and the electrolyte was calculated to be 77 and 90 meV for BUTY-VA and OCTY-CA MAPbBr3 PQD films, respectively. Moreover, passivating PQDs with capping ligands with 12 carbon atoms (DODE-LA) almost completely insulates the PQDs and diminishes charge transport. This is also observed in transient photocurrent density measurements. The results suggest that the inter-PQD distance in this solid film is too long for effective tunneling to occur. However, using BUTY-VA capping ligands to improve electronic properties of PQD solid film comes with a cost of stability.

6.
Chemistry ; 25(19): 5014-5021, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30682220

RESUMO

CH3 NH3 PbBr3 perovskite quantum dots (PQDs) are synthesized by using four different linear alkyl phosphonic acids (PAs) in conjunction with (3-aminopropyl)triethoxysilane (APTES) as capping ligands. The resultant PQDs are characterized by means of XRD, TEM, Raman spectroscopy, FTIR spectroscopy, UV/Vis, photoluminescence (PL), time-resolved PL, and X-ray photoelectron spectroscopy (XPS). PA chain length is shown to control the PQD size (ca. 2.9-4.2 nm) and excitonic absorption band positions (λ=488-525 nm), with shorter chain lengths corresponding to smaller sizes and bluer absorptions. All samples show a high PL quantum yield (ca. 46-83 %) and high PL stability; this is indicative of a low density of band gap trap states and effective surface passivation. Stability is higher for smaller PQDs; this is attributed to better passivation due to better solubility and less steric hindrance of the shorter PA ligands. Based on the FTIR, Raman, and XPS results, it is proposed that Pb2+ and CH3 NH3 + surface defects are passivated by R-PO3 2- or R-PO2 (OH)- , whereas Br- surface defects are passivated by R-NH3 + moieties. This study establishes the combination of PA and APTES ligands as a highly effective dual passivation system for the synergistic passivation of multiple surface defects of PQDs through primarily ionic bonding.

7.
Phys Chem Chem Phys ; 21(3): 1336-1343, 2019 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-30574959

RESUMO

The development of new antioxidants with quick absorbance of free radicals and excellent biocompatibility has drawn intensive attention in recent years. Graphene quantum dots (GQDs) seemed to be one of the most promising antioxidants because of their appropriate antioxidant activity, unique structure, excellent biocompatibility, and low toxicity. However, the relatively low antioxidant activity in comparison with inorganic semiconductor materials and unclear antioxidant mechanism limited their application in cells. In this paper, we further explored their antioxidant mechanism by focusing on the relationship between antioxidant activity and surface oxygen functional groups. The total oxygen fraction was controlled by post-preparation reduction using NaBH4 and the type of oxygen functional groups was adjusted by free radicals during the preparation of GQDs. The degree of reduction and content of surface oxygen groups were determined by X-ray photoelectron spectroscopy (XPS), and the antioxidant activity was obtained by scavenging of 1,1-diphenyl-2-picryl-hydrazyl (DPPH˙) and hydroxyl (˙OH) free radicals. Based on the analysis of XPS, Raman, and Fourier-transform infrared (FT-IR) spectra, the relationship between antioxidant activity and the surface oxygen groups of GQDs was obtained, and the antioxidant mechanism of GQDs was revealed with a particular specification of each oxygen group in the antioxidant activity of GQDs, meanwhile, the biocompatibility of GQDs has been demonstrated by cytotoxicity tests. We hope that our results will provide a new insight into a complete antioxidant mechanism of GQDs.


Assuntos
Sequestradores de Radicais Livres/química , Grafite/química , Oxigênio/química , Pontos Quânticos/química , Compostos de Bifenilo/química , Radical Hidroxila/química , Oxirredução , Espectroscopia Fotoeletrônica , Picratos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman
8.
Chem Soc Rev ; 47(16): 6101-6127, 2018 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-30022215

RESUMO

As a two-dimensional (2D) material, molybdenum disulfide (MoS2) exhibits unique electronic and optical properties useful for a variety of optoelectronic applications including light harvesting. In this article, we review recent progress in the synthesis, properties and applications of MoS2 and related heterostructures. Heterostructured materials are developed to add more functionality or flexibility compared to single component materials. Our focus is on their novel properties and functionalities as well as emerging applications, especially in the areas of light energy harvesting or conversion. We highlight the correlation between structural properties and other properties including electronic, optical, and dynamic. Whenever appropriate, we also try to provide fundamental insight gained from experimental as well as theoretical studies. Finally, we discuss some current challenges and opportunities in technological applications of MoS2.

9.
Anal Chem ; 88(3): 1617-24, 2016 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-26745577

RESUMO

By electrodeposition and galvanic replacement reaction, we developed a facile, time-saving, cost-effective, and environmentally friendly, two-step synthesis route to obtain a controllable cobalt oxide/Au hierarchically nanostructured electrode for glucose sensing. The nanomaterials were characterized by transmission electron microscopy, scanning electron microscopy, Raman spectroscopy, energy-dispersive spectrometry, and X-ray photoelectron spectroscopy, meanwhile, the sensing performance was investigated by cyclic voltammetry and amperometric response. The results revealed that this novel electrode exhibited excellent electrocatalytic performance toward glucose oxidation, with a wide double-linear range from 0.2 µM to 20 mM and a low detection limit of 0.1 µM based on a signal-to-noise ratio of 3, which was mainly attributed to the ability of loading a small amount of Au with good electron conductivity on the surface of cobalt oxide nanosheets with large active surface area and synergistic electrocatalytic activity of Au and cobalt oxide toward glucose electrooxidation. This facile, sensitive, and selective glucose sensor is also proven to be suitable for the detection of glucose in human serum.


Assuntos
Cobalto/química , Glucose/análise , Ouro/química , Nanoestruturas/química , Óxidos/química , Técnicas Eletroquímicas , Eletrodos , Humanos , Tamanho da Partícula , Propriedades de Superfície
10.
Exp Eye Res ; 127: 290-8, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25245083

RESUMO

Selective glucocorticoid receptor agonists (SEGRAs) are a new class of compounds under clinical evaluation for treatment of ocular inflammation. Widely prescribed therapeutics, such as glucocorticoids, are effective at reducing ocular inflammation, but their long term use predisposes to undesirable side effects. The purpose of this study was to investigate a novel SEGRA, mapracorat (BOL-303242-X), and the differences in mapracorat's mechanism of action compared with traditional steroids (i.e. dexamethasone). Keratocytes from three different humans were cultured and treated with mapracorat or dexamethasone, with and without a strong provoking agent, interleukin (IL)-1ß. The effects of mapracorat compared to dexamethasone were determined by measuring protein levels (Western blotting) and DNA binding (ELISA) for two nuclear factor-kappaB (NF-κB) family members, RelA and RelB. Cytokine production (i.e. IL-6, IL-8, prostaglandin E2 (PGE2)) was characterized by immunoassay. Our findings reveal mechanistic differences between mapracorat and traditional steroid therapies. Mapracorat showed partial attenuation of the classical NF-κB pathway, consistent with traditional steroids. However, mapracorat uniquely potentiated a novel anti-inflammatory mechanism through rapid upregulation of RelB, an anti-inflammatory member of the NF-κB alternative pathway. Mapracorat potently inhibits ocular inflammation in vitro and is a promising new treatment for ocular inflammatory disease. Mapracorat acts, in part, by a novel mechanism via upregulation of RelB in the NF-κB alternative pathway.


Assuntos
Anti-Inflamatórios/farmacologia , Benzofuranos/farmacologia , Ceratócitos da Córnea/efeitos dos fármacos , NF-kappa B/metabolismo , Pentanóis/farmacologia , Quinolinas/farmacologia , Receptores de Glucocorticoides/agonistas , Fator de Transcrição RelB/metabolismo , Western Blotting , Células Cultivadas , Ceratócitos da Córnea/metabolismo , Citocinas/metabolismo , Dexametasona/farmacologia , Ensaio de Imunoadsorção Enzimática , Glucocorticoides/farmacologia , Humanos , Fator de Transcrição RelA/metabolismo , Regulação para Cima
11.
Water Res ; 258: 121774, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38772316

RESUMO

Sustainable and rapid production of high-valent cobalt-oxo (Co(IV)=O) species for efficiently removing organic pollutants is challenging in permoxymonosulfate (PMS) based advanced-oxidation-processes (AOPs) due to the limitation of the high 3d-orbital electronic occupancy of Co and slow conversion from Co(III) to Co(II). Herein, S-scheme BiOCl-OV/CoAl-LDH heterojunction were constructed by ultrathin BiOCl with the oxygen-vacancy (OV) self-assembled with ultrathin CoAl-LDH. OV promoted the formation of charge transfer channel (Bi-O-Co bonds) at the interface of the heterojunction and reduced electron occupation of the Co 3d-orbital to facilitate the generation of Co(IV)=O in the BiOCl-OV/CoAl-LDH/PMS/Visible-light system. S-scheme heterojunction accelerated the photogenerated electrons to allow rapid conversion of Co(III) to Co(II), promoting the fast two-electron transfer from Co(II) to Co(IV)=O. Consequently, the developed BiOCl-OV/CoAl-LDH/PMS/Visible-light system showed excellent degradation efficiency for most of organic pollutions, and exhibited very high removal capability for the actual industrial wastewater. This study provides a new insight into the evolution of Co(IV)=O and the coordinative mechanism for photocatalysis and PMS activation.


Assuntos
Cobalto , Cobalto/química , Catálise , Peróxidos/química , Oxirredução , Poluentes Químicos da Água/química
12.
J Biol Chem ; 287(42): 35212-35221, 2012 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-22898817

RESUMO

Mapracorat is a novel selective glucocorticoid receptor agonist (SEGRA), structurally distinct from corticosteroids. In preclinical studies, mapracorat potently inhibits the production of a variety of inflammatory mediators including cytokines and prostaglandin E2 (PGE(2)), with limited side effects associated with traditional corticosteroids. The objective of this study was to delineate the mechanisms underlying the anti-inflammatory properties of mapracorat. We found that mapracorat potently inhibited the production of GM-CSF and TNF-α in LPS-stimulated Raw 264.7 macrophages. Mapracorat also substantially attenuated the expression of COX-2 and the production of PGE(2). The inhibition of mapracorat on the inflammatory response was dose-dependent, and substantially inhibitory effects were observed at concentrations in the 10-100 nm range. Examination of the activation kinetics of p38 and its downstream target MAPK-activated protein kinase-2 (MK-2) revealed a shortened activation course after LPS stimulation in cells pretreated with mapracorat. Supporting the notion that mapracorat augments a feedback control mechanism restraining the p38 pathway, we found that mapracorat enhanced the expression of MAPK phosphatase-1 (MKP-1), a critical negative regulator of MAPKs that drive the production of cytokines and other inflammatory mediators. While mapracorat alone did not stimulate MKP-1 expression, it markedly enhanced the expression of MKP-1 in cells stimulated by LPS, in a similar manner and potency to the augmenting effect of dexamethasone. Blocking MKP-1 expression by triptolide also abolished the accelerating effects of mapracorat on p38 and MK-2 deactivation, further supporting a role of MKP-1 in the anti-inflammatory mechanism of mapracorat. Taken together, these results indicate that mapracorat exerts its anti-inflammatory effects, at least in part, by augmenting MKP-1 expression.


Assuntos
Anti-Inflamatórios/farmacologia , Benzofuranos/farmacologia , Fosfatase 1 de Especificidade Dupla/biossíntese , Fosfatase 1 de Especificidade Dupla/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Macrófagos/enzimologia , Pentanóis/farmacologia , Quinolinas/farmacologia , Receptores de Glucocorticoides/antagonistas & inibidores , Animais , Antineoplásicos Alquilantes/farmacologia , Linhagem Celular , Dexametasona/farmacologia , Diterpenos/farmacologia , Relação Dose-Resposta a Droga , Fosfatase 1 de Especificidade Dupla/genética , Compostos de Epóxi/farmacologia , Regulação Enzimológica da Expressão Gênica/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/biossíntese , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos/citologia , Camundongos , Fenantrenos/farmacologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Fator de Necrose Tumoral alfa/biossíntese , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
13.
Mol Vis ; 19: 1515-25, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23878502

RESUMO

PURPOSE: To determine the ocular anti-allergic effects of mapracorat, a novel selective glucocorticoid receptor agonist (SEGRA) in primary human conjunctival fibroblasts and epithelial cells. METHODS: Two primary human conjunctival cell types, human conjunctival epithelial cells (HConEpiC) and human conjunctival fibroblasts (HConF), were challenged with interleukin-4 (IL-4) or IL-13 plus tumor necrosis factor-alpha (TNF-α). Luminex technology was used to profile the resulting inflammatory response. The effects of mapracorat on the release of eotaxin and regulated on activation, normal T cell expressed and secreted (RANTES), two allergy-related chemokines, as well as proinflammatory cytokines and intercellular adhesion molecule 1 (ICAM-1) were then determined. Small interfering RNA was used to determine whether the effects of mapracorat were mediated via the glucocorticoid receptor (GR). Dexamethasone was used as the control. RESULTS: IL-13 or IL-4 plus TNF-α in the HConF or HConEpiC significantly increased eotaxin-1 (HConF only), eotaxin-3, RANTES, multiple proinflammatory cytokines, and ICAM-1. Synergistic effects of IL-13 or IL-4 plus TNF-α were observed in the HConEpiC for RANTES and monocyte chemoattractant protein-1, and in the HConF for eotaxin-1, eotaxin-3, and RANTES. Mapracorat significantly reduced IL-4 or IL-13 plus TNF-α-induced cytokine release and ICAM-1 protein in a dose-dependent manner in both cell types, with comparable efficacy to dexamethasone. These effects were mediated through the glucocorticoid receptor (GR), as demonstrated by the reversal of inhibitory effects after silencing of glucocorticoid receptor expression. CONCLUSIONS: Data from these in vitro models indicate that mapracorat is efficacious and potent in reducing IL-4 or IL-13 plus TNF-α-induced release of allergy-related and proinflammatory cytokines from the HConF and the HConEpiC, supporting clinical evaluation of the compound in reducing allergic and inflammatory reactions in allergic conjunctivitis.


Assuntos
Antialérgicos/farmacologia , Benzofuranos/farmacologia , Túnica Conjuntiva/patologia , Células Epiteliais/metabolismo , Fibroblastos/metabolismo , Pentanóis/farmacologia , Quinolinas/farmacologia , Receptores de Glucocorticoides/agonistas , Animais , Anti-Inflamatórios/farmacologia , Bovinos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Inativação Gênica/efeitos dos fármacos , Humanos , Hipersensibilidade/metabolismo , Hipersensibilidade/patologia , Molécula 1 de Adesão Intercelular/metabolismo , Interleucina-13/farmacologia , Interleucina-4/farmacologia , Receptores de Glucocorticoides/metabolismo , Fator de Necrose Tumoral alfa/farmacologia
14.
J Phys Chem Lett ; 14(24): 5489-5496, 2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37289830

RESUMO

Using ligand exchange on FAPbI3 perovskite nanocrystals (PNCs) surface with chiral tridentate l-cysteine (l-cys) ligand, we successfully prepared chiral FAPbI3 PNCs that show circularly polarized luminescence (CPL) (dissymmetry factor; glum = 2.1 × 10-3) in the near-infrared (NIR) region from 700 to 850 nm and a photoluminescence quantum yield (PLQY) of 81%. The chiral characteristics of FAPbI3 PNCs are ascribed to induction by chiral l/d-cys, and the high PLQY is attributed to the passivation of the PNCs defects with l-cys. Also, effective passivation of defects on the surface of FAPbI3 PNCs by l-cys results in excellent stability toward atmospheric water and oxygen. The conductivity of the l-cys treated FAPbI3 NC films is improved, which is attributed to the partial substitution of l-cys for the insulating long oleyl ligand. The CPL of the l-cys ligand treated FAPbI3 PNCs film retains a glum of -2.7 × 10-4. This study demonstrates a facile yet effective approach to generating chiral PNCs with CPL for NIR photonics applications.

15.
Cell Rep ; 42(2): 112075, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36774551

RESUMO

Booster immunizations and breakthrough infections can elicit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron subvariant neutralizing activity. However, the durability of the neutralization response is unknown. We characterize the sensitivity of BA.1, BA.2, BA.2.75, BA.4/BA.5, BF.7, BQ.1.1, and XBB against neutralizing antibodies from vaccination, hybrid immunity, and breakthrough infections 4-6 months after vaccination and infection. We show that a two-dose CoronaVac or a third-dose ZF2001 booster elicits limited neutralization against Omicron subvariants 6 months after vaccination. Hybrid immunity as well as Delta, BA.1, and BA.2 breakthrough infections induce long-term persistence of the antibody response, and over 70% of sera neutralize BA.1, BA.2, BA.4/BA.5, and BF.7. However, BQ.1.1 and XBB, followed by BA.2.75, are more resistant to neutralization, with neutralizing titer reductions of ∼9- to 41-fold, ∼16- to 63-fold, and ∼4- to 25-fold, respectively. These data highlight additional vaccination in CoronaVac- or ZF2001-vaccinated individuals and provide insight into the durability of neutralization against Omicron subvariants.


Assuntos
Infecções Irruptivas , COVID-19 , Humanos , COVID-19/prevenção & controle , SARS-CoV-2 , Anticorpos Neutralizantes , Anticorpos Antivirais
16.
J Phys Chem Lett ; 13(45): 10543-10549, 2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36342415

RESUMO

Nanosized molecular clusters (MCs) composed of PbBr2 and neutral ligand butylamine (BTYA) with unique optical properties in solution and solid states have been synthesized using ligand-assisted reprecipitation and spin-coating, separately. The studies of their optical properties using ultraviolet-visible (UV-vis) absorption and photoluminescence (PL) show the first electronic absorption and PL band of the MCs at 401 and 411 nm, respectively, for the solution and solid state samples that exhibit good stability under ambient conditions. Low-temperature PL spectra below 30 K show vibronic peaks indicative of a single size or a very narrow size distribution of the MCs. On the basis of Raman, X-ray diffraction, and transmission electron microscopy measurements, a layered structural model is proposed for the MCs with a BTYA ligand capping on the surface of the corner-shared tilted [PbBr6]4- octahedral framework. The stable and retained structure of MCs in the solid state is promising for photonics applications.


Assuntos
Ligantes , Difração de Raios X , Microscopia Eletrônica de Transmissão
17.
ACS Appl Mater Interfaces ; 14(40): 45725-45733, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36190450

RESUMO

Two-dimensional (2D) hybrid layered perovskites (HLPs) have attracted extensive attention due to their excellent optoelectronic properties. Herein, we successfully prepared high-quality Mn-doped BDACdBr4 (BDA = NH2(CH2)4NH2, butylene diammonium) HLP single crystals (SCs). The incorporation of Mn2+ ions modulates the electronic band structure of BDACdBr4 perovskites and tailors the energy transfer process of excited states. A near-unity photoluminescence (PL) quantum yield of 96% from the Mn2+ emission at 608 nm is achieved. Excitation wavelength-dependent spectroscopic characterizations help to clarify the energy transfer mechanism of Mn-doped BDACdBr4, in which competing PL from the 3Eg → 1A1g transition of Cd2+ and the 4T1(G) → 6A1(S) transition of Mn2+ dopants is observed. Temperature-dependent PL spectroscopic characterizations indicate that the efficient energy transfer from BDACdBr4 perovskite host to Mn2+ dopants requires thermal activation to overcome a potential barrier. This work provides new insight into the photophysics and optical properties of 2D HLPs, especially the influence of Mn2+ doping on competing energy transfer in hybrid luminescent materials.

18.
J Phys Chem Lett ; 13(36): 8529-8536, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36067065

RESUMO

A2BIBIIIX6 double perovskites are promising materials due to their outstanding photoelectronic properties and excellent stability in the environment. Herein, we synthesized Mn2+:Cs2NaTbCl6 with dual emission through a solvothermal method for the first time. Mn2+:Cs2NaTbCl6 double perovskites exhibit excellent environmental stability and high photoluminescence quantum yields (PLQYs). The Cs2NaTbCl6 was successfully doped with Mn2+ in two modes: at Mn-feeding concentrations below 1%, Mn2+ first tend to insert into the interstitial void, but if the Mn-feeding concentration exceeds 1%, Mn2+ will further substitute Na+ site of the Cs2NaTbCl6 lattice and thus both two doping modes coexist. After Mn2+ doping, efficient energy transfer from the 5D4 level of Tb3+ ions to the 4T1 level of Mn2+ ions occurs, resulting in tunable dual emission from the Tb3+5D4 → 7FJ=6,5,4,3 transition and Mn2+4T1 → 6A1 transition. Further, LED based on the Mn2+:Cs2NaTbCl6 double perovskites exhibits excellent performance and stability. This work demonstrates a strategy to achieve novel lanthanide-based double perovskites with potential applications in photonics.

19.
Mol Vis ; 17: 533-42, 2011 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-21364905

RESUMO

PURPOSE: To determine the anti-inflammatory and anti-oxidant effects of epigallocatechin gallate (EGCG), the major polyphenol component of green tea, in human corneal epithelial cells (HCEpiC). METHODS: HCEpiC were challenged with interleukin-1ß (IL-1ß) for 18 h or hyperosmolarity (440 mOsm) for 24 h. Luminex technology was used to determine the effects of EGCG (0.3-30 µM) on IL-1ß- or hyperosmolar-induced cytokine release into the medium. Cell metabolic activity was measured using the alamarBlue assay. Effects of EGCG on mitogen-activated protein kinase (MAPK) phosphorylation were determined by cell-based enzyme-linked immunosorbent assay (ELISA) and western blotting. Effects of EGCG on nuclear factor kappa B (NFκB) and activator protein-1 (AP-1) transcriptional activity were assessed by reporter gene assay. The effects of EGCG on glucose oxidase (GO)-induced reactive oxygen species (ROS) production was determined using the ROS probe CM-H2DCFDA. RESULTS: Treatment of HCEpiC with 1 ng/ml IL-1ß for 18 h significantly increased release of the cytokines/chemokines granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-6 (IL-6), interleukin-8 (IL-8), and monocyte chemotactic protein-1 (MCP-1), while hyperosmolarity-induced release of IL-6 and MCP-1. When cells were treated with IL-1ß and EGCG or hyperosmolarity and EGCG there was a dose-dependent reduction in release of these cytokines/chemokines, with significant inhibition observed at 3-30 µM. There was no effect of EGCG on cell metabolic activity at any of the doses tested (0.3-30 µM). EGCG significantly inhibited phosphorylation of the MAPKs p38 and c-Jun N-terminal kinase (JNK), and NFκB and AP-1 transcriptional activities. There was a significant dose-dependent decrease in GO-induced ROS levels after treatment of HCEpiC with EGCG. CONCLUSIONS: EGCG acts as an anti-inflammatory and anti-oxidant agent in HCEpiC and therefore may have therapeutic potential for ocular inflammatory conditions such as dry eye.


Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Catequina/análogos & derivados , Células Epiteliais/efeitos dos fármacos , Epitélio Corneano/citologia , Flavonoides/farmacologia , Fenóis/farmacologia , Chá/química , Catequina/farmacologia , Citocinas/metabolismo , Ativação Enzimática/efeitos dos fármacos , Células Epiteliais/enzimologia , Glucose Oxidase/metabolismo , Humanos , Interleucina-1beta/farmacologia , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Pressão Osmótica/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Polifenóis , Espécies Reativas de Oxigênio/metabolismo , Fator de Transcrição AP-1/metabolismo , Ativação Transcricional/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
20.
Mol Vis ; 17: 1056-63, 2011 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-21552500

RESUMO

PURPOSE: The Schirmer's test is commonly used in the clinic for the diagnosis of dry eye disease by measuring tear volume. This report describes a procedure which can be used to recover tears from the Schirmer strip for the measurement of multiple tear cytokines as well as matrix metalloproteinases (MMPs) by Luminex technology. METHODS: Cytokine and MMP recovery was determined by using spiked Schirmer strips presoaked with known cytokines or MMPs prepared in PBS with 1% BSA. In a clinical study, tears were collected from 5 subjects using Schirmer strips. Strips were stored on ice immediately after removal from the subject and stored dry at -20 °C for 16-24 h. Cytokines were extracted from the Schirmer strip in 0.5 M NaCl with 0.5% Tween-20. Concentrations of cytokines and MMPs in collected tear samples were analyzed by Luminex using both a 10-cytokine and a 5-MMP kit. RESULTS: The standard curves for the assay in both the kit assay buffer and extraction buffer were identical for 9 of the 10 cytokines and all 5 MMPs. In the clinical sample all the cytokines (interleukin 1α [IL-1α], IL-1ß, IL-1ra, IL-4, IL-6, IL-8, IL-10, IL-13, monocyte chemotactic protein-1 [MCP-1], and tumor necrosis factor-α [TNF-α]) and 5 MMPs (MMP-1, MMP-2, MMP-7, MMP-9, and MMP-10) tested were detected in at least 50% of the 10 subject samples. Recoveries from extracted Schirmer strips were >60% for 8 of the 10 cytokines and all MMPs. CONCLUSIONS: Numerous cytokines and MMPs were detected in the tear samples collected using the Schirmer strip, including many that have been implicated in ocular surface disease. This procedure may be used to evaluate the cytokine and MMP content in tear samples in clinical studies, especially for the evaluation of dry eye therapeutics. Because the Schirmer test is routine in the assessment of dry eye, this method offers the opportunity to evaluate both the quantity and quality of the tears.


Assuntos
Bioensaio , Citocinas/análise , Metaloproteinases da Matriz/análise , Lágrimas/química , Xeroftalmia/metabolismo , Adulto , Automação Laboratorial , Citocinas/biossíntese , Olho/metabolismo , Olho/patologia , Feminino , Humanos , Luminescência , Medições Luminescentes , Masculino , Metaloproteinases da Matriz/biossíntese , Pessoa de Meia-Idade , Polissorbatos/química , Fitas Reagentes/análise , Padrões de Referência , Cloreto de Sódio/química , Xeroftalmia/patologia
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