Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
ACS Appl Mater Interfaces ; 15(47): 54766-54772, 2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-37963334

RESUMEN

Millimeter-wave and short-range wireless communication is an important part of the Internet of Things due to its advantages of high transmission speed and large data capacity. In this paper, two antenna arrays operating at typical millimeter-wave bands (45 and 60 GHz) based on graphene-assembled films (GAF) are proposed for short-range wireless communication application. The 45 GHz graphene-assembled film antenna array is in the form of a magnetoelectric dipole antenna with a strip slot coupling to achieve bidirectional radiation, which offers an operating bandwidth of 40-49.5 GHz with a realized gain of 11.8 dBi. The 60 GHz graphene-assembled film antenna utilizes a microstrip discontinuous radiation array to achieve radiation with an operating bandwidth of 59-64 GHz, reaching the peak realized gain of 14.92 dBi over the working frequency. Finally, we proposed an experimental validation to verify the transmission performance of both antenna arrays in an actual conference room. The results show that the signal drops slowly in the room with drop rates of 0.064 dB/cm (at 45 GHz) and 0.071 dB/cm (at 60 GHz), while it steeply dropped through the wall with the drop rates of 2.3 and 3.13 dB/cm, more than 35-fold difference in signal drop rates in the room and through the wall. It has been confirmed that the proposed antenna arrays can successfully realize fast indoor short-range wireless communication while also preventing signal leakage through walls, thereby enhancing the security of information. In summary, this is the first time that we have applied graphene-based materials to millimeter-wave and short-range wireless communications, revealing the significant potential of carbon-based materials in high-frequency communication systems.

3.
Materials (Basel) ; 14(17)2021 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-34501177

RESUMEN

Flexible electronic devices are widely used in the Internet of Things, smart home and wearable devices, especially in carriers with irregular curved surfaces. Light weight, flexible and corrosion-resistant carbon-based materials have been extensively investigated in RF electronics. However, the insufficient electrical conductivity limits their further application. In this work, a flexible and low-profile dual-band Vivaldi antenna based on highly conductive graphene-assembled films (GAF) is proposed for 5G Wi-Fi applications. The proposed GAF antenna with the profile of 0.548 mm comprises a split ring resonator and open circuit half wavelength resonator to implement the dual band-notched characteristic. The operating frequency of the flexible GAF antenna covers the Wi-Fi 6e band, 2.4-2.45 GHz and 5.15-7.1 GHz. Different conformal applications are simulated by attaching the antenna to the surface of cylinders with different radii. The measured results show that the working frequency bands and the radiation patterns of the GAF antenna are relatively stable, with a bending angle of 180°. For demonstration of practical application, the GAF antennas are conformed to a commercial router. The spectral power of the GAF antenna router is greater than the copper antenna router, which means a higher signal-to-noise ratio and a longer transmission range can be achieved. All results indicate that the proposed GAF antenna has broad application prospects in next generation Wi-Fi.

4.
FEBS Open Bio ; 11(11): 2933-2942, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34110111

RESUMEN

Choroidal neovascularization (CNV) is a key characteristic of wet age-related macular degeneration (AMD) that can lead to severe vision loss in the elderly. Anti-VEGF therapy is currently the premier strategy for wet AMD, but it has limited efficacy. Previous studies have shown that chitinase-3-like-1 (YKL-40) can promote microangiogenesis and inflammation, but its effect on CNV formation has not yet been studied. Here, we investigated the potential role of YKL-40 in wet AMD and the underlying mechanism(s). We report that the serum expression of YKL-40 in wet AMD patients was significantly higher than that in control patients and was positively correlated with VEGF expression, indicating that YKL-40 may participate in the development of wet AMD. In addition, YKL-40 and VEGF expression levels were observed to be increased and the ERK1/2 pathway activated in the neuroretinal (NR) and RPE/choroid tissues of mice with laser-induced CNV. The YKL-40 and phosphorylated protein levels of the ERK1/2 pathway were decreased after intravitreal injection with an anti-YKL-40 antibody, suggesting that anti-YKL-40 could inhibit the activation of the ERK1/2 pathway. These results indicate that YKL-40 may serve as a novel target for the diagnosis and treatment of wet AMD.


Asunto(s)
Proteína 1 Similar a Quitinasa-3/metabolismo , Sistema de Señalización de MAP Quinasas/fisiología , Degeneración Macular Húmeda/genética , Anciano , Inhibidores de la Angiogénesis/uso terapéutico , Animales , China , Proteína 1 Similar a Quitinasa-3/sangre , Proteína 1 Similar a Quitinasa-3/genética , Neovascularización Coroidal/tratamiento farmacológico , Neovascularización Coroidal/metabolismo , Femenino , Humanos , Inflamación , Sistema de Señalización de MAP Quinasas/genética , Degeneración Macular/genética , Degeneración Macular/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Neovascularización Patológica/tratamiento farmacológico , Neovascularización Patológica/genética , Neovascularización Patológica/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Factores de Crecimiento Endotelial Vascular/metabolismo , Degeneración Macular Húmeda/metabolismo
5.
Exp Neurol ; 334: 113462, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32916173

RESUMEN

Traumatic brain injury (TBI) has been regarded as one of the leading cause of injury-related death and disability. White matter injury after TBI is characterized by axon damage and demyelination, resulting in neural network impairment and neurological deficit. Brain-derived neurotrophic factor (BDNF) can promote white matter repair. The activation of peroxisome proliferator-activated receptor gamma (PPARγ) has been reported to promote microglia/macrophages towards anti-inflammatory state and therefore to promote axon regeneration. Bexarotene, an agonist of retinoid X receptor (RXR), can activate RXR/PPARγ heterodimers. The aim of the present study was to identify the effect of bexarotene on BDNF in microglia/macrophages and axon sprouting after TBI in mice. Bexarotene was administered intraperitoneally in C57BL/6 mice undergoing controlled cortical impact (CCI). PPARγ dependency was determined by intraperitoneal administration of a PPARγ antagonist T0070907. We found that bexarotene promoted axon regeneration indicated by increased growth associated protein 43 (GAP43) expression, myelin basic protein (MBP) expression, and biotinylated dextran amine (BDA)+ axon sprouting. Bexarotene also increased microglia/macrophages-specific brain derived neurotrophic factor (BDNF) expression after TBI. In addition, bexarotene reduced the number of pro-inflammatory microglia/macrophages while increased the number of anti-inflammatory microglia/macrophages after TBI. Moreover, bexaortene inhibited pro-inflammatory cytokine secretion. In addition, bexarotene treatment improved neurological scores and cognitive function of CCI-injured mice. These effects of bexarotene were partially abolished by T0070907. In conclusion, bexarotene promotes axon sprouting, increases microglia/macrophages-specific BDNF expression, and induces microglia/macrophages from a pro-inflammatory state towards an anti-inflammatory one after TBI at least partially in a PPARγ-dependent manner.


Asunto(s)
Axones/efectos de los fármacos , Bexaroteno/uso terapéutico , Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Factor Neurotrófico Derivado del Encéfalo/biosíntesis , Macrófagos/efectos de los fármacos , Microglía/efectos de los fármacos , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Axones/metabolismo , Bexaroteno/farmacología , Lesiones Traumáticas del Encéfalo/metabolismo , Lesiones Traumáticas del Encéfalo/patología , Factor Neurotrófico Derivado del Encéfalo/genética , Expresión Génica , Macrófagos/metabolismo , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Aprendizaje por Laberinto/fisiología , Ratones , Ratones Endogámicos C57BL , Microglía/metabolismo , Regeneración Nerviosa/efectos de los fármacos , Regeneración Nerviosa/fisiología
6.
ACS Appl Mater Interfaces ; 12(5): 5642-5657, 2020 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-31940169

RESUMEN

Retinoblastoma (RB) is prone to delayed diagnosis or treatment and has an increased likelihood of metastasizing. Thus, it is crucial to perform an effective imaging examination and provide optimal treatment of RB to prevent metastasis. Nanoparticles that support diagnostic imaging and targeted therapy are expected to noninvasively integrate tumor diagnosis and treatment. Herein, we report a multifunctional nanoparticle for multimodal imaging-guided low-intensity focused ultrasound (LIFU)/immunosynergistic RB therapy. Magnetic hollow mesoporous gold nanocages (AuNCs) conjugated with Fe3O4 nanoparticles (AuNCs-Fe3O4) were prepared to encapsulate muramyl dipeptide (MDP) and perfluoropentane (PFP). The multimodal imaging capabilities, antitumor effects, and dendritic cell (DC) activation capacity of these nanoparticles combined with LIFU were explored in vitro and in vivo. The biosafety of AuNCs-Fe3O4/MDP/PFP was also evaluated systematically. The multifunctional magnetic nanoparticles enhanced photoacoustic (PA), ultrasound (US), and magnetic resonance (MR) imaging in vivo and in vitro, which was helpful for diagnosis and efficacy evaluation. Upon accumulation in tumors via a magnetic field, the nanoparticles underwent phase transition under LIFU irradiation and MDP was released. A combined effect of AuNCs-Fe3O4/MDP/PFP and LIFU was recorded and verified. AuNCs-Fe3O4/MDP/PFP enhanced the therapeutic effect of LIFU and led to direct apoptosis/necrosis of tumors, while MDP promoted DC maturation and activation and activated the ability of DCs to recognize and clear tumor cells. By enhancing PA/US/MR imaging and inhibiting tumor growth, the multifunctional AuNC-Fe3O4/MDP/PFP nanoparticles show great potential for multimodal imaging-guided LIFU/immunosynergistic therapy of RB. The proposed nanoplatform facilitates cancer theranostics with high biosafety.


Asunto(s)
Nanopartículas Multifuncionales , Imagen Multimodal/métodos , Retinoblastoma , Terapia por Ultrasonido/métodos , Acetilmuramil-Alanil-Isoglutamina/química , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Femenino , Fluorocarburos/química , Humanos , Nanopartículas de Magnetita/química , Ratones , Ratones Desnudos , Nanopartículas Multifuncionales/química , Nanopartículas Multifuncionales/metabolismo , Nanopartículas Multifuncionales/toxicidad , Retinoblastoma/diagnóstico por imagen , Retinoblastoma/metabolismo , Nanomedicina Teranóstica/métodos
7.
Cell Cycle ; 18(11): 1241-1253, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31081721

RESUMEN

Researches have been focusing on the role of Slit2 in angiogenesis, specifically in cell migration and vessel permeability. Nevertheless, the role of Slit2-N, the bioactive fragment of Slit2, in the proliferation of vascular endothelia in choroidal neovascularization and some related mechanisms have not been studied yet. Thus, our study aimed to explore the role of Slit2-N in proliferation of vascular endothelia and the related mechanisms in choroidal neovascularization. Fluorescein isothiocyanate perfusion and HE staining were performed to evaluate volumes of choroidal neovascularization lesions. The effect of Slit2-N on VEGF165-induced cell proliferation and some related mechanisms were detected by CCK8 assay, flow cytometry, siRNA transfection, and western blotting. We found that Slit2-N reduced volumes of laser-induced choroidal neovascularization networks in vivo. Results of the in vitro study showed Slit2-N reduced VEGF165-induced cell proliferation of both human umbilical vascular endothelial cells and human microvascular endothelial cells possibly via activation of AKT rather than that of ERK1/2. Additionally, Robo4, one of the receptors binding to Slit2-N, was involved in the inhibitory effect of Slit2-N. Generally, our findings revealed the inhibitory role of Slit2-N in proliferation of vascular endothelia and some related mechanisms, and presented some potential targets, molecules along Slit2-N-Robo4-AKT axis, to choroidal neovascularization therapy.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Neovascularización Coroidal/patología , Endotelio Vascular/efectos de los fármacos , Péptidos y Proteínas de Señalización Intercelular/farmacología , Proteínas del Tejido Nervioso/farmacología , Factor A de Crecimiento Endotelial Vascular/farmacología , Animales , Células Cultivadas , Neovascularización Coroidal/tratamiento farmacológico , Neovascularización Coroidal/metabolismo , Endotelio Vascular/patología , Endotelio Vascular/fisiología , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/fisiología , Humanos , Péptidos y Proteínas de Señalización Intercelular/química , Péptidos y Proteínas de Señalización Intercelular/fisiología , Péptidos y Proteínas de Señalización Intercelular/uso terapéutico , Masculino , Neovascularización Patológica/inducido químicamente , Neovascularización Patológica/metabolismo , Neovascularización Patológica/patología , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/fisiología , Proteínas del Tejido Nervioso/uso terapéutico , Fragmentos de Péptidos/farmacología , Fragmentos de Péptidos/uso terapéutico , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Endogámicas BN , Receptores de Superficie Celular/metabolismo , Transducción de Señal/efectos de los fármacos , Factor A de Crecimiento Endotelial Vascular/química
8.
Mol Vis ; 24: 509-517, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30090014

RESUMEN

Purpose: The aim of this study was to investigate the roles of chitosan in inflammation and adipogenesis of primary cultured orbital fibroblasts in Graves ophthalmopathy (GO). Methods: Cell viability, apoptosis, and cell cycle were determined with the Cell Counting Kit-8 (CCK-8), the Annexin V-FITC/PI kit, and flow cytometry, respectively. Inflammation of orbital fibroblasts was stimulated by interleukin-1 beta (IL-1ß). The levels of IL-6 and prostaglandin E-2 (PGE-2) were measured using an enzyme-linked immunosorbent assay (ELISA). The expression of cyclooxygenase-2 (COX-2) was measured with real-time PCR and western blot assay. Phosphorylation of c-Jun N-terminal kinase (JNK) was evaluated with western blot assay. An inhibitor of JNK was used to investigate the signal transduction pathway of cytokine production. Orbital fibroblasts differentiated to adipose cells in differentiation medium. Adipose cells were dyed with Oil Red O. FABP4, adiponectin, C/EBPα, PPAR-γ, and phosphorylation of AKT were evaluated with western blot assay. Results: The results showed that IL-1ß statistically significantly increased the expression of IL-6, PGE-2, and COX-2 in orbital fibroblasts. Phosphorylation of JNK was promoted by IL-1ß. IL-6 and PGE-2 were modulated by the JNK signaling pathway as determined with the inhibition experiments. Chitosan downregulated expression of IL-1ß-stimulated IL-6, COX-2, and PGE-2 and downregulated phosphorylation of JNK. Chitosan inhibited the production of adipose cells dyed by Oil Red O. Chitosan statistically significantly decreased the protein levels of FABP4, adiponectin, C/EBPα, and PPAR-γ with downregulation of AKT phosphorylation during adipocyte differentiation. Conclusions: Chitosan statistically significantly inhibits inflammation and adipogenesis, as well as related signaling pathways, of orbital fibroblasts in GO. This indicates a possible therapeutic effect of chitosan on Graves ophthalmopathy.


Asunto(s)
Adipocitos/efectos de los fármacos , Antiinflamatorios no Esteroideos/farmacología , Quitosano/farmacología , Fibroblastos/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Oftalmopatía de Graves/genética , Adipocitos/metabolismo , Adipocitos/patología , Adiponectina/genética , Adiponectina/metabolismo , Apoptosis/efectos de los fármacos , Proteínas Potenciadoras de Unión a CCAAT/genética , Proteínas Potenciadoras de Unión a CCAAT/metabolismo , Ciclo Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Ciclooxigenasa 2/genética , Ciclooxigenasa 2/metabolismo , Dinoprostona/biosíntesis , Dinoprostona/metabolismo , Proteínas de Unión a Ácidos Grasos/genética , Proteínas de Unión a Ácidos Grasos/metabolismo , Femenino , Fibroblastos/metabolismo , Fibroblastos/patología , Oftalmopatía de Graves/metabolismo , Oftalmopatía de Graves/patología , Humanos , Interleucina-1beta/antagonistas & inhibidores , Interleucina-1beta/farmacología , Interleucina-6/genética , Interleucina-6/metabolismo , MAP Quinasa Quinasa 4/genética , MAP Quinasa Quinasa 4/metabolismo , Masculino , Persona de Mediana Edad , Órbita/efectos de los fármacos , Órbita/metabolismo , Órbita/patología , PPAR gamma/genética , PPAR gamma/metabolismo , Cultivo Primario de Células , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal
9.
Front Immunol ; 9: 1713, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30090104

RESUMEN

Uveitis is characterized as a common cause of blindness worldwide. Aryl hydrocarbon receptor (AhR), a ligand-activated nuclear receptor, has been implicated to play a role in human uveitis, although the exact mechanisms remain poorly understood. The purpose of this study was to enhance our knowledge concerning the role of AhR during intraocular inflammation. We immunized wild-type and AhR-knockout C57BL/6J mice with IRBP651-670 to induce experimental autoimmune uveitis (EAU). Disease severity was evaluated with both clinical and histopathological grading. Blood-retinal barrier (BRB) integrity was tested by Evans blue and tight junction proteins qualifications. Apoptosis was measured using TdT-mediated dUTP nick end labeling staining. Macrophage/microglia activation and polarization were studied by immunofluorescence and Western blot. Following EAU induction, AhR-/- mice had more severe clinical and histopathological manifestations of uveitis than AhR+/+ mice. Increased vascular permeability and apoptotic cells were observed in AhR-/- EAU mice when compared with AhR+/+ EAU mice. In addition, AhR-/- EAU mice showed evidence of a significantly increased macrophage/microglia cells and a stronger polarization from the M2 to the M1 phenotype as compared to AhR+/+ EAU mice. The levels of pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-1ß were increased in AhR-/- EAU mice, which was associated with the activation of NF-κB and signal transducers and activators of transcription (STAT) pathways. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), an agonist of AhR, caused a significant decrease in the clinical and histopathological manifestations, preserved BRB integrity, reduced apoptotic cells, inhibited macrophage/microglia activation, and shifted their polarization from M1 toward M2. Moreover, decreased expression of pro-inflammatory cytokines including TNF-α, IL-6, and IL-1ß and inhibition of NF-κB and STAT pathways were found in EAU mice following TCDD treatment. In conclusion, AhR activation with TCDD exhibits an immunomodulatory effect by reducing BRB breakdown, inhibiting retinal cell apoptosis, and reducing pro-inflammatory cytokine expression during EAU. The underlying mechanism may involve the modulation of macrophages/microglia polarization and the downregulation of NF-κB and STAT pathways.

10.
Mol Vis ; 23: 538-547, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28761327

RESUMEN

PURPOSE: Vogt-Koyanagi-Harada (VKH) disease is a systemic autoimmune disease that can lead to blindness. This study was designed to investigate whether interleukin (IL)-9 plays a role in the development of VKH disease. METHODS: IL-9, IL-17, and interferon (IFN)-γ levels, present in the supernatants of cultured peripheral blood mononuclear cells (PBMCs) and CD4+T cells, were assessed with enzyme-linked immunosorbent assay. IL-9 mRNA expression in PBMCs was measured with real-time quantitative PCR. The proliferation of PBMCs in response to different doses of recombinant human IL-9 (rIL-9) was measured using the Cell Counting Kit-8 assay. RESULTS: IL-9 mRNA levels in PBMCs were statistically significantly elevated in patients with active VKH disease compared to those in patients with inactive VKH disease (p<0.05) and normal controls (p<0.05). Statistically significantly higher expression of IL-9 was observed in the supernatants of stimulated PBMCs (p<0.01) and CD4+ T cells (p<0.01) from patients with active VKH disease compared to that in cells from patients with inactive VKH disease and normal controls. rIL-9 at a concentration of 100 ng/ml did not induce proliferation of PBMCs (p>0.05). After the PBMCs and CD4+ T cells were stimulated with rIL-9 (100 ng/ml), the secretion of IL-17 was increased statistically significantly (p<0.05), whereas the level of IFN-γ was not statistically significantly altered (p>0.05). CONCLUSIONS: These findings suggest that IL-9 is involved in the pathogenesis of VKH disease, and that IL-9 might also enhance the inflammatory response by increasing the secretion of IL-17, an established proinflammatory cytokine in VKH disease. Manipulation of IL-9 could represent a novel option for the treatment of VKH disease.


Asunto(s)
Regulación de la Expresión Génica/fisiología , Interleucina-9/genética , Síndrome Uveomeningoencefálico/genética , Adulto , Linfocitos T CD4-Positivos/metabolismo , Recuento de Células , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Interferón gamma/genética , Interleucina-17/genética , Leucocitos Mononucleares/metabolismo , Masculino , Persona de Mediana Edad , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...