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1.
Neurogenetics ; 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38958838

RESUMO

Glioma, a type of brain tumor, poses significant challenges due to its heterogeneous nature and limited treatment options. Interferon-related genes (IRGs) have emerged as potential players in glioma pathogenesis, yet their expression patterns and clinical implications remain to be fully elucidated. We conducted a comprehensive analysis to investigate the expression patterns and functional enrichment of IRGs in glioma. This involved constructing protein-protein interaction networks, heatmap analysis, survival curve plotting, diagnostic and prognostic assessments, differential expression analysis across glioma subgroups, GSVA, immune infiltration analysis, and drug sensitivity analysis. Our analysis revealed distinct expression patterns and functional enrichment of IRGs in glioma. Notably, IFNW1 and IFNA21 were markedly downregulated in glioma tissues compared to normal tissues, and higher expression levels were associated with improved overall survival and disease-specific survival. Furthermore, these genes showed diagnostic capabilities in distinguishing glioma tissues from normal tissues and were significantly downregulated in higher-grade and more aggressive gliomas. Differential expression analysis across glioma subgroups highlighted the association of IFNW1 and IFNA21 expression with key pathways and biological processes, including metabolic reprogramming and immune regulation. Immune infiltration analysis revealed their influence on immune cell composition in the tumor microenvironment. Additionally, elevated expression levels were associated with increased resistance to chemotherapeutic agents. Our findings underscore the potential of IFNW1 and IFNA21 as diagnostic biomarkers and prognostic indicators in glioma. Their roles in modulating glioma progression, immune response, and drug sensitivity highlight their significance as potential therapeutic targets. These results contribute to a deeper understanding of glioma biology and may inform the development of personalized treatment strategies for glioma patients.

2.
Biomacromolecules ; 25(7): 4014-4029, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38832927

RESUMO

This study presents a comprehensive characterization of the viscoelastic and structural properties of bovine submaxillary mucin (BSM), which is widely used as a commercial source to conduct mucus-related research. We conducted concentration studies of BSM and examined the effects of various additives, NaCl, CaCl2, MgCl2, lysozyme, and DNA, on its rheological behavior. A notable connection between BSM concentration and viscoelastic properties was observed, particularly under varying ionic conditions. The rheological spectra could be well described by a fractional Kelvin-Voigt model with a minimum of model parameters. A detailed proteomics analysis provided insight into the protein, especially mucin composition within BSM, showing MUC19 as the main component. Cryo-scanning electron microscopy enabled the visualization of the porous BSM network structure. These investigations give us a more profound comprehension of the BSM properties, especially those pertaining to viscoelasticity, and how they are influenced by concentration and environmental conditions, aspects relevant to the field of mucus research.


Assuntos
Hidrogéis , Mucinas , Animais , Bovinos , Mucinas/química , Hidrogéis/química , Viscosidade , Elasticidade , Reologia , Glândula Submandibular/química , Glândula Submandibular/metabolismo
3.
BMC Cardiovasc Disord ; 24(1): 166, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38504170

RESUMO

BACKGROUND: Cardiovascular disease (CVD) is one among the major causes of mortality all round the globe. Several anti-platelet regimens have been proposed following percutaneous coronary intervention (PCI). In this analysis, we aimed to show the adverse clinical outcomes associated with ticagrelor monotherapy after a short course of dual antiplatelet therapy (DAPT) with ticagrelor and aspirin following PCI in patients with versus without diabetes mellitus (DM). METHODS: Electronic databases were searched by four authors from September to November 2023. Cardiovascular outcomes and bleeding events were the endpoints of this analysis. Revman 5.4 software was used to conduct this meta-analysis. Risk ratio (RR) and 95% confidence intervals (CI) were used to represent the results which were generated. RESULTS: Three studies with a total number of 22,574 participants enrolled from years 2013 to 2019 were included in this analysis. Results of this analysis showed that DM was associated with significantly higher risks of major adverse cardiovascular events (RR: 1.73, 95% CI: 1.49 - 2.00; P = 0.00001), all-cause mortality (RR: 2.15, 95% CI: 1.73 - 2.66; P = 0.00001), cardiac death (RR: 2.82, 95% CI: 1.42 - 5.60; P = 0.003), stroke (RR: 1.78, 95% CI: 1.16 - 2.74; P = 0.009), myocardial infarction (RR: 1.63, 95% CI: 1.17 - 2.26; P = 0.004) and stent thrombosis (RR: 1.74, 95% CI: 1.03 - 2.94; P = 0.04) when compared to patients without DM. However, thrombolysis in myocardial infarction (TIMI) defined minor and major bleedings, bleeding defined according to the academic research consortium (BARC) type 3c (RR: 1.31, 95% CI: 0.14 - 11.90; P = 0.81) and BARC type 2, 3 or 5 (RR: 1.17, 95% CI: 0.85 - 1.62; P = 0.34) were not significantly different. CONCLUSION: In patients who were treated with ticagrelor monotherapy after a short course of DAPT with ticagrelor and aspirin, DM was an independent risk factor for the significantly increased adverse cardiovascular outcomes. However, TIMI and BARC defined bleeding events were not significantly different in patients with versus without DM.


Assuntos
Diabetes Mellitus , Infarto do Miocárdio , Intervenção Coronária Percutânea , Humanos , Ticagrelor , Aspirina/efeitos adversos , Inibidores da Agregação Plaquetária/uso terapêutico , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Hemorragia/induzido quimicamente , Diabetes Mellitus/tratamento farmacológico , Resultado do Tratamento
4.
Mikrochim Acta ; 191(6): 307, 2024 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-38713296

RESUMO

An assay that integrates histidine-rich peptides (HisRPs) with high-affinity aptamers was developed enabling the specific and sensitive determination of the target lysozyme. The enzyme-like activity of HisRP is inhibited by its interaction with a target recognized by an aptamer. In the presence of the target, lysozyme molecules progressively assemble on the surface of HisRP in a concentration-dependent manner, resulting in the gradual suppression of enzyme-like activity. This inhibition of HisRP's enzyme-like activity can be visually observed through color changes in the reaction product or quantified using UV-visible absorption spectroscopy. Under optimal conditions, the proposed colorimetric assay for lysozyme had a detection limit as low as 1 nM and exhibited excellent selectivity against other nonspecific interferents. Furthermore, subsequent research validated the practical applicability of the developed colorimetric approach to saliva samples, indicating that the assay holds significant potential for the detection of lysozymes in samples derived from humans.


Assuntos
Colorimetria , Muramidase , Saliva , Muramidase/análise , Muramidase/química , Muramidase/metabolismo , Colorimetria/métodos , Humanos , Saliva/química , Saliva/enzimologia , Limite de Detecção , Peptídeos/química , Aptâmeros de Nucleotídeos/química , Proteínas/análise , Técnicas Biossensoriais/métodos , Histidina/análise , Histidina/química
5.
Int J Mol Sci ; 25(8)2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38673941

RESUMO

Abdominal aortic aneurysm (AAA) is a serious vascular disease which is associated with vascular remodeling. CD38 is a main NAD+-consuming enzyme in mammals, and our previous results showed that CD38 plays the important roles in many cardiovascular diseases. However, the role of CD38 in AAA has not been explored. Here, we report that smooth-muscle-cell-specific deletion of CD38 (CD38SKO) significantly reduced the morbidity of AngII-induced AAA in CD38SKOApoe-/- mice, which was accompanied with a increases in the aortic diameter, medial thickness, collagen deposition, and elastin degradation of aortas. In addition, CD38SKO significantly suppressed the AngII-induced decreases in α-SMA, SM22α, and MYH11 expression; the increase in Vimentin expression in VSMCs; and the increase in VCAM-1 expression in smooth muscle cells and macrophage infiltration. Furthermore, we demonstrated that the role of CD38SKO in attenuating AAA was associated with the activation of sirtuin signaling pathways. Therefore, we concluded that CD38 plays a pivotal role in AngII-induced AAA through promoting vascular remodeling, suggesting that CD38 may serve as a potential therapeutic target for the prevention of AAA.


Assuntos
ADP-Ribosil Ciclase 1 , Angiotensina II , Aneurisma da Aorta Abdominal , Camundongos Knockout , Miócitos de Músculo Liso , Remodelação Vascular , Animais , Masculino , Camundongos , ADP-Ribosil Ciclase 1/metabolismo , ADP-Ribosil Ciclase 1/genética , Aneurisma da Aorta Abdominal/induzido quimicamente , Aneurisma da Aorta Abdominal/genética , Aneurisma da Aorta Abdominal/patologia , Modelos Animais de Doenças , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Camundongos Endogâmicos C57BL , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Cadeias Pesadas de Miosina/metabolismo , Cadeias Pesadas de Miosina/genética , Transdução de Sinais , Remodelação Vascular/genética
6.
Plant Physiol ; 190(4): 2122-2136, 2022 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-35947689

RESUMO

Linarin (acacetin-7-O-rutinoside), isorhoifolin (apigenin-7-O-rutinoside), and diosmin (diosmetin-7-O-rutinoside) are chemically and structurally similar flavone rutinoside (FR) compounds found in Chrysanthemum L. (Anthemideae, Asteraceae) plants. However, their biosynthetic pathways remain largely unknown. In this study, we cloned and compared FRs and genes encoding rhamnosyltransferases (RhaTs) among eight accessions of Chrysanthemum polyploids. We also biochemically characterized RhaTs of Chrysanthemum plants and Citrus (Citrus sinensis and Citrus maxima). RhaTs from these two genera are substrate-promiscuous enzymes catalyzing the rhamnosylation of flavones, flavanones, and flavonols. Substrate specificity analysis revealed that Chrysanthemum 1,6RhaTs preferred flavone glucosides (e.g. acacetin-7-O-glucoside), whereas Cs1,6RhaT preferred flavanone glucosides. The nonsynonymous substitutions of RhaTs found in some cytotypes of diploids resulted in the loss of catalytic function. Phylogenetic analysis and specialized pathways responsible for the biosynthesis of major flavonoids in Chrysanthemum and Citrus revealed that rhamnosylation activity might share a common evolutionary origin. Overexpression of RhaT in hairy roots resulted in 13-, 2-, and 5-fold increases in linarin, isorhoifolin, and diosmin contents, respectively, indicating that RhaT is mainly involved in the biosynthesis of linarin. Our findings not only suggest that the substrate promiscuity of RhaTs contributes to the diversity of FRs in Chrysanthemum species but also shed light on the evolution of flavone and flavanone rutinosides in distant taxa.


Assuntos
Chrysanthemum , Citrus , Diosmina , Flavonas , Chrysanthemum/genética , Chrysanthemum/química , Filogenia , Flavonoides , Flavonas/química , Glucosídeos/química
7.
Opt Lett ; 48(21): 5591-5594, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37910710

RESUMO

Broadband and efficient terahertz (THz) absorbers are crucial for various applications in sensing, imaging, detecting, and modulation. Although recent studies have reported a series of THz metamaterials for enhanced absorption, achieving high absorption across the entire ultrabroad terahertz band remains challenging. We propose a novel, to the best of our knowledge, method to design ultra-wideband terahertz absorbers using a water-filled Fabry-Perot cavity with continuously varying cavity length. Our design achieves over 90% absorption across an ultrabroad terahertz band ranging from 0.26 to 30 THz. Furthermore, the design method can be extended to the visible, infrared, and microwave regimes. We believe that our method will inspire further studies and applications of ultra-wideband absorbers.

8.
Can J Physiol Pharmacol ; 101(7): 369-381, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37192549

RESUMO

Obesity is a metabolic syndrome characterized by abnormal lipid deposition and energy imbalance. CD38 is a single-chain transmembrane glycoprotein widely expressed in a variety of cell types. The roles of skeletal muscle and brown fat in CD38 deficiency under HFD-induced obesity remain unknown. In this study, we established obesity model with HFD and examined the changes in metabolites with metabonomics. Our results showed that CD38 expression was increased in muscle and brown fat after HFD treatment. Moreover, the results of metabonomics showed that CD38 deficiency significantly altered the metabolites in energy metabolism, cofactor generation, and redox homeostasis. Furthermore, CD38 deficiency reduced the expressions of NADPH oxidase 2 and FASN in mRNA level. We found that the expressions of Sirt1, Sirt3, and PGC1α were upregulated in CD38-deficient muscle tissue. In brown fat, the Sirt1-3, cell death inducing DFFA-like effector A, ELOVL3, and Dio2 expressions were increased in CD38-deficient mice. Our results showed the uncoupling protein 1 expression was upregulated. And NAD+ supplementation increased the expression of Sirt1 and PGC1α after palmitic acid treatment. Taken together, our results demonstrated that the protection of CD38 deficiency on HFD-induced obesity was related to the inhibition of oxidative stress and increasing energy expenditure via activating NAD+/Sirtuins signaling pathways in muscle and brown fat.


Assuntos
Tecido Adiposo Marrom , NAD , Animais , Camundongos , Tecido Adiposo Marrom/metabolismo , Dieta Hiperlipídica , Metabolismo Energético , Camundongos Endogâmicos C57BL , Músculo Esquelético/metabolismo , NAD/metabolismo , Obesidade/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Transdução de Sinais , Sirtuína 1/metabolismo
9.
Int J Mol Sci ; 24(21)2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-37958991

RESUMO

Diabetic cardiomyopathy is one of the diabetes mellitus-induced cardiovascular complications that can result in heart failure in severe cases, which is characterized by cardiomyocyte apoptosis, local inflammation, oxidative stress, and myocardial fibrosis. CD38, a main hydrolase of NAD+ in mammals, plays an important role in various cardiovascular diseases, according to our previous studies. However, the role of CD38 in diabetes-induced cardiomyopathy is still unknown. Here, we report that global deletion of the CD38 gene significantly prevented diabetic cardiomyopathy induced by high-fat diet plus streptozotocin (STZ) injection in CD38 knockout (CD38-KO) mice. We observed that CD38 expression was up-regulated, whereas the expression of Sirt3 was down-regulated in the hearts of diabetic mice. CD38 deficiency significantly promoted glucose metabolism and improved cardiac functions, exemplified by increased left ventricular ejection fraction and fractional shortening. In addition, we observed that CD38 deficiency markedly decreased diabetes or high glucose and palmitic acid (HG + PA)-induced pyroptosis and apoptosis in CD38 knockout hearts or cardiomyocytes, respectively. Furthermore, we found that the expression levels of Sirt3, mainly located in mitochondria, and its target gene FOXO3a were increased in CD38-deficient hearts and cardiomyocytes with CD38 knockdown under diabetic induction conditions. In conclusion, we demonstrated that CD38 deficiency protected mice from diabetes-induced diabetic cardiomyopathy by reducing pyroptosis and apoptosis via activating NAD+/Sirt3/FOXO3a signaling pathways.


Assuntos
Diabetes Mellitus Experimental , Cardiomiopatias Diabéticas , Sirtuína 3 , Animais , Camundongos , Apoptose , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Cardiomiopatias Diabéticas/genética , Cardiomiopatias Diabéticas/metabolismo , Mamíferos/metabolismo , Miócitos Cardíacos/metabolismo , NAD/metabolismo , Estresse Oxidativo , Piroptose , Sirtuína 3/metabolismo , Volume Sistólico , Função Ventricular Esquerda
10.
Biochem Biophys Res Commun ; 603: 63-68, 2022 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-35278881

RESUMO

Endometrial epithelial cells play a significant role in the "dialogue" between the embryo and the mother, but in vitro studies to clarify this are hampered by the limited lifespan of primary cells. As such, it is necessary to develop an in vitro model to study endometrial function. Morphological analysis showed that the pEECs were homogeneous, formed characteristic cobblestone monolayers, and expressed the epithelial cell-specific marker, cytokeratin 18. The isolated and purified cells were transfected with a plasmid encoding human telomerase reverse transcriptase (TERT) gene, pCI-neo-TERT, to establish an immortal endometrial epithelial cell line (iEECs). The transfected cells were cultured with G418 and monoclonal cells were selected for expanded culture. Expression of TERT mRNA was detected by RT-qPCR and protein was quantitated by Western blot. TERT expression was stable and continued to be active with no signs of aging. Assays for cell proliferation and apoptosis indicated higher proliferation and cellular activity in iEECs than pEECs. After stimulated by interferon tau (IFN-τ), both iEECs and pEECs showed similar upregulation levels in all the underlying genes. Taken together, these findings demonstrate that iEECs retained the basic morphology and function of pEECs, providing a robust in vitro model for study of the function of ovine endometrial epithelial cells.


Assuntos
Endométrio , Telomerase , Animais , Apoptose , Linhagem Celular , Proliferação de Células , Endométrio/metabolismo , Células Epiteliais/metabolismo , Feminino , Ovinos , Telomerase/genética , Telomerase/metabolismo
11.
Planta ; 255(6): 122, 2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35554686

RESUMO

MAIN CONCLUSION: AaZFP1, a C2H2-type transcription factor, was found to bind the AGT-N1-10-AGT box of AaIPPI1pro and activate the expression of AaIPPI1 involved in artemisinin biosynthesis. Artemisinin, an endoperoxide sesquiterpene lactone, is a widely used antimalarial drug isolated from Artemisia annua L. Isopentenyl pyrophosphate isomerase (AaIPPI1) catalyzes the interconversion of isopentenyl diphosphate and dimethylallyl diphosphate and is the key gene involved in the biosynthesis of artemisinin. However, the AaIPPI1 gene regulation network remains largely unknown. Here, we isolated the AaIPPI1 promoter (AaIPPI1pro) and predicted that it contains cis-elements involved in stress responses, including the TGACG motif (a methyl jasmonate-responsive element), GARE motif (a gibberellin-responsive element), ABRE (an abscisic acid-responsive element), TC-rich repeats (a stress-responsive element), and the AGT-N1-10-AGT box, which is the binding site of Cys/His2 zinc finger protein (C2H2 ZFP). The C2H2 ZFP gene AaZFP1 was discovered by screening a cDNA library using AaIPPI1pro as bait in yeast. AaZFP1 contains two conserved C2H2 regions, a nuclear localization domain (B box), a Leu-rich domain (L box), and a conserved DLN sequence (DLN box) close to its C terminus. A subcellular localization assay indicated that AaZFP1 protein is localized in the nucleus and cytoplasm. An electrophoretic mobility shift assay demonstrated that AaZFP1 binds to the AGT-N1-10-AGT box of AaIPPI1pro. A dual-luciferase assay indicated that AaZFP1 enhanced the promoter activity of AaIPPI1 in vivo. Transient overexpression of AaZFP1 in A. annua increased the expression of AaIPPI1 and the content of artemisinin. Our data demonstrated that AaZFP1 functions as a transcriptional activator that regulates the expression of AaIPPI1 by directly binding to its promoter. The present study provides insights into the transcriptional regulation of genes involved in artemisinin biosynthesis in A. annua.


Assuntos
Artemisia annua , Artemisininas , Dedos de Zinco CYS2-HIS2 , Ácido Abscísico/metabolismo , Artemisia annua/genética , Artemisia annua/metabolismo , Artemisininas/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
12.
Opt Express ; 30(7): 10229-10238, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35472995

RESUMO

Photonic crystal lasers with a high-Q factor and small mode volume are ideal light sources for on-chip nano-photonic integration. Due to the submicron size of their active region, it is usually difficult to achieve high output power and single-mode lasing at the same time. In this work, we demonstrate well-selected single-mode lasing in a line-defect photonic crystal cavity by coupling it to the high-Q modes of a short double-heterostructure photonic crystal cavity. One of the FP-like modes of the line-defect cavity can be selected to lase by thermo-optically tuning the high-Q mode of the short cavity into resonance. Six FP-like modes are successively tuned into lasing with side mode suppression ratios all exceeding 15 dB. Furthermore, we show a continuous wavelength tunability of about 10 nm from all the selected modes. The coupled cavity system provides a remarkable platform to explore the rich laser physics through the spatial modulation of vacuum electromagnetic field at submicron scale.

13.
BMC Geriatr ; 22(1): 936, 2022 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-36471251

RESUMO

BACKGROUND: Although frailty is a common geriatric syndrome in old adults, a simple method to assess the degree of frailty in a person has not yet been established. In this study we have tried to establish the association between calf circumference (CC) and frailty among older Chinese people. METHODS: We used the data obtained from the 2014 edition of the Chinese Longitudinal Healthy Longevity Survey; 1216 participants aged ≥60 years were included for the study. Body mass index, CC and waist circumference measurement data, and laboratory test results were collected. Frailty status was measured using the frailty index (FI). Participants were then classified into non-frail (FI < 0.25) and frail (FI ≥ 0.25) groups. RESULTS: There were 874 participants (71.9%) in the non-frail group and 342 (28.1%) in the frail group. The CC was significantly different between the two groups (31.54 ± 4.16 versus 28.04 ± 4.53, P < 0.001). Logistic regression analysis revealed that CC (odds ratio = 0.947, 95% confidence interval: 0.904-0.993, P = 0.023) was an independent impact factor associated with frailty. The CC value of 28.5 cm was considered the best cut-off value in women with area under the curve (AUC) was 0.732 (P < 0.001) and 29.5 cm in men with AUC was 0.592 (P = 0.004);We created a simple prediction model for frailty that included age,sex and CC:[Formula: see text]P = elogit(P) /1 + elogit(P), and AUC is 0.849 (P < 0.001). CONCLUSIONS: CC is a convenient and predictable marker of frailty in older adults.


Assuntos
Fragilidade , Idoso , Masculino , Feminino , Humanos , Fragilidade/diagnóstico , Fragilidade/epidemiologia , Idoso Fragilizado , Avaliação Geriátrica/métodos , Longevidade , China/epidemiologia
14.
Phys Rev Lett ; 127(7): 077204, 2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34459630

RESUMO

An insulating ferromagnetic (FM) phase exists in the quasi-one-dimensional iron oxychalcogenide Ce_{2}O_{2}FeSe_{2}, but its origin is unknown. To understand the FM mechanism, here a systematic investigation of this material is provided, analyzing the competition between ferromagnetic and antiferromagnetic tendencies and the interplay of hoppings, Coulomb interactions, Hund's coupling, and crystal-field splittings. Our intuitive analysis based on second-order perturbation theory shows that large entanglements between doubly occupied and half filled orbitals play a key role in stabilizing the FM order in Ce_{2}O_{2}FeSe_{2}. In addition, via many-body computational techniques applied to a multiorbital Hubbard model, the phase diagram confirms the proposed FM mechanism.

15.
Langmuir ; 37(2): 949-956, 2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33405936

RESUMO

The use of metal ions to bridge the fluorescent materials to target analytes has been demonstrated to be a promising way to sensor design. Herein, the effect of rare-earth ions on the fluorescence of l-methionine-stabilized gold nanoclusters (Met-AuNCs) was investigated. It was found that europium (Eu3+) can significantly suppress the emission of Met-AuNCs, while other rare-earth ions showed a negligible impact. The mechanism on the observed fluorescence quenching of Met-AuNCs triggered by Eu3+ was systematically explored, with results revealing the dominant role of photoinduced electron transfer (PET). Eu3+ can bind to the surface of Met-AuNCs by the coordination effect and accepts the electron from the excited Met-AuNCs, which results in Met-AuNC fluorescence suppression. After introducing dipicolinic acid (DPA), an excellent biomarker for spore-forming pathogens, Eu3+ was removed from the surface of Met-AuNCs owing to the higher binding affinity between Eu3+ and DPA. Consequently, an immediate fluorescence recovery occurred when DPA was present in the system. Based on the Met-AuNC/Eu3+ ensemble, we then established a simple and sensitive fluorescence strategy for turn-on determination of biomarker DPA, with a linear range of 0.2-4 µM and a low limit of detection of 110 nM. The feasibility of the proposed method was further validated by the quantitative detection of DPA in the soil samples. We believe that this study would significantly facilitate the construction of metal-ion-mediated PET sensors for the measurement of various interested analytes by applying fluorescent AuNCs as detection probes.

16.
Can J Physiol Pharmacol ; 99(8): 803-811, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33356884

RESUMO

Inflammation-induced activation and dysfunction of endothelial cells play an important role in the pathology of multiple vascular diseases. Nicaraven, a potent hydroxyl radical scavenger, has recently been found to have anti-inflammatory roles; however, the mechanism of its action is not fully understood. Here we investigated the effects of Nicaraven on tumor necrosis factor α (TNFα) - induced inflammatory response in human umbilical vein endothelial cells and we explore the underlying mechanisms related to the nuclear factor-κB (NF-κB) signaling pathway. Our results showed that Nicaraven significantly reduced the reactive oxygen species production after TNFα stimulation. Nicaraven suppressed TNFα-induced mRNA expression of multiple adhesion molecules and pro-inflammatory cytokines, including vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), E-selectin, MCP-1, TNFα, interleukin-1ß (IL-1ß), IL-6, and IL-8. In addition, Nicaraven inhibited monocyte adhesion and reduced the protein levels of VCAM-1 and ICAM-1. Mechanistically, Nicaraven prevented TNFα-induced activation of NF-κB signaling pathway by suppressing the phosphorylation of NF-κB p65, IκBα, and IκB kinase (IKK)α/ß, stabilizing IκBα, and inhibiting the translocation of p65 from cytosol to nucleus. Finally, we showed that Nicaraven improved the functions of endothelial cells, seen as the upregulation of endothelial nitric oxide synthase and increased nitric oxide levels. Our findings indicated that Nicaraven effectively inhibits TNFα-induced endothelial activation and inflammatory response at least partly through inhibiting NF-κB signaling pathway.


Assuntos
NF-kappa B , Células Endoteliais da Veia Umbilical Humana , Humanos , Transdução de Sinais
17.
Appl Opt ; 60(16): 4835-4840, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34143037

RESUMO

A tunable broadband terahertz (THz) absorber based on vanadium dioxide (${{\rm VO}_2}$) and graphene is proposed. The absorber, consisting of the ${{\rm VO}_2}$ square loop, polymethacrylimide (PMI) dielectric layer, and a layer of unpatterned graphene, can achieve absorption over 90% from 1.04 THz to 5.51 THz and relative bandwidth of up to 136.5% under normal incidence. Its absorption bandwidth and absorption peak can be adjusted by changing the conductivity of ${{\rm VO}_2}$ or the chemical potential of graphene. The physical mechanism of the absorber is analyzed in detail by the use of the impedance matching theory and the electric field distributions of the ${{\rm VO}_2}$ layer and graphene layer. The proposed absorber, with polarization insensitivity and incidence angle of 30° for both TE and TM polarizations, may have potential applications in tunable sensors, modulators, and imaging.

18.
Opt Express ; 28(24): 36316-36326, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33379728

RESUMO

Metasurfaces provide an extraordinary way to control electromagnetic waves by abrupt change of optical properties within an optically thin interface. In this paper, by introducing vanadium dioxide (VO2) into the metasurface, efficient tunable terahertz phase modulation is designed to realize independent control of linearly and circularly polarized terahertz waves. The working resonator of the metasurface can be adjustable by controlling the temperature of VO2, resulting in the tunable function between resonant phase for linearly polarized waves and Pancharatnam-Berry phase for circularly polarized waves. As a proof of concept, two metasurfaces are designed for integrating two distinct functionalities in one structure, i.e. 1-bit metasurface switched between the abnormal THz deflector and the THz scatter and 3-bit metasurface switched between the vortex THz transmitter and the THz focusing mirror. The proposed tunable resonator structure provides a flexible way for extending the functionality of metadevice, which has a great potential value in integrated optics and wearable optics.

19.
Opt Express ; 28(11): 16486-16496, 2020 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-32549470

RESUMO

The effective manipulation of mode oscillation and competition is of fundamental importance for controlling light emission in semiconductor lasers. Here we develop a rate equation model which considers the spatially modulated gain and spontaneous emission, which are inherently governed by the ripple of the vacuum electromagnetic field in a Fabry-Pérot (FP) microcavity. By manipulating the interplay between the spatial oscillation of the vacuum field and external optical injection via dual-beam laser interference, single longitudinal mode operation is observed in a FP-type microcavity with a side mode suppression ratio exceeding 40 dB. An exploration of this extended rate equation model bridges the gap between the classical model of multimode competition in semiconductor lasers and a quantum-optics understanding of radiative processes in microcavities.

20.
FASEB J ; 33(12): 14118-14128, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31647884

RESUMO

The mitochondrial complexes are prone to sirtuin (Sirt)3-mediated deacetylation modification, which may determine cellular response to stimuli, such as oxidative stress. In this study, we show that the cytochrome c oxidase (COX)-1, a core catalytic subunit of mitochondrial complex IV, was acetylated and deactivated both in 2,2'-azobis(2-amidinopropane) dihydrochloride-treated NIH/3T3 cells and hydrogen peroxide-treated primary neuronal cells, correlating with apoptotic cell death induction by oxidative stress. Inhibition of Sirt3 by small interfering RNA or the inhibitor nicotinamide induced accumulation of acetylation of COX-1, reduced mitochondrial membrane potential, and increased cell apoptosis. In contrast, overexpression of Sirt3 enhanced deacetylation of COX-1 and inhibited oxidative stress-induced apoptotic cell death. Significantly, rats treated with ischemia/reperfusion injury, a typical oxidative stress-related disease, presented an inhibition of Sirt3-induced hyperacetylation of COX-1 in the brain tissues. Furthermore, K13, K264, K319, and K481 were identified as the acetylation sits of COX-1 in response to oxidative stress. In conclusion, COX-1 was discovered as a new deacetylation target of Sirt3, indicating that the Sirt3/COX-1 axis is a promising therapy target of stress-related diseases.-Tu, L.-F., Cao, L.-F., Zhang, Y.-H., Guo, Y.-L., Zhou, Y.-F., Lu, W.-Q., Zhang, T.-Z., Zhang, T., Zhang, G.-X., Kurihara, H., Li, Y.-F., He, R.-R. Sirt3-dependent deacetylation of COX-1 counteracts oxidative stress-induced cell apoptosis.


Assuntos
Isquemia Encefálica , Ciclo-Oxigenase 1/metabolismo , Proteínas de Membrana/metabolismo , Traumatismo por Reperfusão , Sirtuína 3/metabolismo , Sirtuínas/metabolismo , Amidinas/farmacologia , Animais , Ciclo-Oxigenase 1/genética , Regulação da Expressão Gênica , Peróxido de Hidrogênio , Proteínas de Membrana/genética , Camundongos , Células NIH 3T3 , Neurônios/metabolismo , Ratos , Ratos Sprague-Dawley , Sirtuína 3/genética , Sirtuínas/genética , Organismos Livres de Patógenos Específicos
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