Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Exp Cell Res ; 393(2): 112108, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32445748

RESUMO

Fibroblast growth factor 21(FGF21) is an endocrine cytokine that targets inflammation and atherosclerosis (AS). However, the underlying molecular mechanisms of the FGF21 anti-AS effect remain to be explored. Pyroptosis induced by hyperlipidemia or oxidized low-density lipoprotein (oxLDL) in vascular endothelial cells (VECs) is a significant step in the advancement of AS. This work aimed to evaluate the mechanisms and functioning of FGF21 against AS using an atherosclerotic animal model and oxLDL mimic in vitro. We found that exogenous treatments with FGF21 significantly reduced the aortic sinus plaque area and ameliorated dyslipidemia in apoE-/- mice. FGF21 attenuated the expression of pyroptosis-related proteins both in vivo and in vitro. Possibly, FGF21 improves mitochondrial function, inhibits mitochondrial division, and reduces ROS production by maintaining mitochondrial dynamics and function to reduce NLRP3 related pyroptosis and inhibits VECs endoplasmic reticulum stress, thereby exerting an anti-atherosclerotic effect.


Assuntos
Células Endoteliais/efeitos dos fármacos , Fatores de Crescimento de Fibroblastos/farmacologia , Inflamassomos/efeitos dos fármacos , Piroptose/efeitos dos fármacos , Animais , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Células Endoteliais/metabolismo , Humanos , Inflamassomos/metabolismo , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Espécies Reativas de Oxigênio/metabolismo
2.
J Nanosci Nanotechnol ; 16(6): 6148-54, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27427684

RESUMO

We demonstrate that moderate hydrogen annealing is a simple and effective approach to substantially improve the photocatalytic activity of TiO2 nanorods via increasing oxygen vacancies in outer layer. Hydrogenated TiO2 nanorods are obtained by annealing in hydrogen atmosphere at various temperatures ranging from 200 degrees C to 350 degrees C. TEM images directly illustrate the disordered layer on the surface of nanorods induced by hydrogen annealing. The photoelectrochemical measurements reveal that the photocurrent is improved first as the temperature increases and reaches to the maximum value at an appropriate temperature (250 degrees C), corresponding to about 50% enhancement compared to the pristine TiO2. Incident photon-to-electron conversion efficiency spectra reveal that the photocurrent improvement is mainly attributed to the enhanced photocatalytic activity of TiO2 in ultraviolet region. Mott-Schottky plots further betray that hydrogen annealing can significantly enhance the electric conductivity, via increasing the oxygen vacancies density in the outer layer. In addition, time-dependent measurements indicate the hydrogenated TiO2 nanorods possess excellent chemical stability. Thus, we believe the hydrogenated TiO2 nanorods would be a promising candidate for photoanode in solar water splitting.


Assuntos
Hidrogênio/química , Nanotubos/química , Oxigênio/química , Luz Solar , Titânio/química , Água/química , Catálise , Eletroquímica , Processos Fotoquímicos
3.
J Nanosci Nanotechnol ; 15(8): 5918-23, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26369172

RESUMO

In this paper, we developed a top-down method to fabricate complex three dimensional silicon structure, which was inspired by the hierarchical micro/nanostructure of the Morpho butterfly scales. The fabrication procedure includes photolithography, metal masking, and both dry and wet etching techniques. First, microscale photoresist grating pattern was formed on the silicon (111) wafer. Trenches with controllable rippled structures on the sidewalls were etched by inductively coupled plasma reactive ion etching Bosch process. Then, Cr film was angled deposited on the bottom of the ripples by electron beam evaporation, followed by anisotropic wet etching of the silicon. The simple fabrication method results in large scale hierarchical structure on a silicon wafer. The fabricated Si structure has multiple layers with uniform thickness of hundreds nanometers. We conducted both light reflection and heat transfer experiments on this structure. They exhibited excellent antireflection performance for polarized ultraviolet, visible and near infrared wavelengths. And the heat flux of the structure was significantly enhanced. As such, we believe that these bio-inspired hierarchical silicon structure will have promising applications in photovoltaics, sensor technology and photonic crystal devices.


Assuntos
Materiais Biomiméticos/síntese química , Borboletas/ultraestrutura , Nanopartículas/ultraestrutura , Impressão Tridimensional , Silício/química , Asas de Animais/ultraestrutura , Animais , Borboletas/química , Luz , Teste de Materiais , Nanopartículas/química , Tamanho da Partícula , Espalhamento de Radiação , Propriedades de Superfície , Condutividade Térmica , Molhabilidade , Asas de Animais/química
4.
J Nanosci Nanotechnol ; 14(6): 4469-74, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24738414

RESUMO

We have developed a novel method to fabricate micro/nano structure based on the coherent diffraction lithography, and acquired periodic silicon tubular gratings with deep nano-scale tapered profiles at the top part. The optical properties of these tubular gratings were similar to an effective gradient-index antireflective surface, resulting in a broadband antireflective combining super-hydrophobic behavior. The mechanism of the method was simulated by rigorous coupled wave analysis algorithms. Then coherent diffraction lithography by use of suitable mask, in which periodic micro-scale circular opaque patters were distributed, was realized on the traditional aligner. Due to coherent diffraction, we obtained enough light intensity for photoresist exposure under the center of the opaque area in the mask together with transparent areas. The tapered line profiles and hollow photoresist gratings over large areas could be fabricated on the silicon wafer after development. The dry etching process was carried out, and high aspect ratio silicon tubular gratings with deep tapered profiles at the top were fabricated. The optical property and wettability of the structure were verified, proving that the proposed method and obtained micro/nano structure provide application potential in the future.


Assuntos
Cristalização/métodos , Lentes , Nanotubos/química , Nanotubos/ultraestrutura , Refratometria/instrumentação , Silício/química , Desenho de Equipamento , Análise de Falha de Equipamento , Interações Hidrofóbicas e Hidrofílicas , Teste de Materiais , Tamanho da Partícula , Propriedades de Superfície
5.
Materials (Basel) ; 16(19)2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37834549

RESUMO

High-temperature forming behaviors of a 7046-aluminum alloy were investigated by hot compression experiments. The microstructural evolution features with the changes in deformation parameters were dissected. Results indicated the formation of massive dislocation clusters/cells and subgrains through the intense DRV mechanism at low compression temperature. With an increase in deformation temperature, the annihilation of dislocations and the coarsening of subgrains/DRX grains became prominent, due to the collaborative effects of the DRV and DRX mechanisms. However, the growth of subgrains and DRX grains displayed the weakening trend at high strain rates. Moreover, two constitutive models involving a physically based (PB) model and a gate recurrent unit (GRU) model were proposed for predicting the hot compression features. By validation analysis, the predicted values of true stress perfectly fit with the experimental data, indicating that both the proposed PB model and the GRU model can accurately predict the hot compression behaviors of 7046-aluminum alloys.

6.
ACS Appl Mater Interfaces ; 15(36): 43135-43144, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37590916

RESUMO

The emerging type II Weyl semimetal 1T' MoTe2 as a promising material in polarization-sensitive photodetectors has aroused much attention due to its narrow bandgap and intrinsic in-plane anisotropic crystal structure. However, the semimetal properties lead to a large dark current and a low response. Herein, we demonstrate for the first time an all-2D semimetal MoTe2/MoS2 van der Waals (vdWs) heterojunction to improve the performance of the photodetectors and realize polarization-sensitive, self-powered, and broadband photodetection and imaging. Owing to the built-in electric field of the heterojunction, the device achieves a self-powered photoresponse ranging from 520 to 1550 nm. Under 915 nm light illumination, the device demonstrates outstanding performance, including a high responsivity of 79 mA/W, a specific detectivity of 1.2 × 1010 Jones, a fast rise/decay time of 180/202 µs, and a high on/off ratio of 1.3 × 10.3 Wavelength-dependent photocurrent anisotropic ratio is revealed to vary from 1.10 at 638 nm to 2.24 at 1550 nm. Furthermore, we demonstrate the polarization imaging capabilities of the device in scattering surroundings, and the DoLP and AoLP images achieve 78% and 112% contrast enhancement, respectively, compared to the S0. This work opens up new avenues to develop anisotropic semimetals heterojunction photodetectors for high-performance polarization-sensitive photodetection and next-generation polarized imaging.

7.
J Thorac Dis ; 13(9): 5383-5394, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34659805

RESUMO

BACKGROUND: Patients with consistent lung pure ground-glass nodules (pGGNs) have a high incidence of lung adenocarcinoma that can be classified as adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), or invasive adenocarcinoma (IAC). Regular follow-up is recommended for AIS and MIA, while surgical resection should be considered for IAC. This study sought to develop a multi-parameter prediction model to increase the diagnostic accuracy in discriminating between IAC and AIS or MIA. METHODS: The training data set comprised consecutive patients with lung pGGNs who underwent resection from January to December 2017 at the Zhongshan Hospital. Of the 370 resected pGGNs, 344 were pathologically confirmed to be AIS, MIA, or IAC and were included in the study. The 26 benign pGGNs were excluded. We compared differences in the clinical features (e.g., age and gender), the content of serum tumor biomarkers, the computed tomography (CT) parameters (e.g., nodule size and the maximal CT value), and the morphologic characteristics of nodules (e.g., lobulation, spiculation, pleura indentation, vacuole sign, and normal vessel penetration or abnormal vessel) between the pathological subtypes of AIS, MIA, and IAC. An abnormal vessel was defined as "vessel curve" or "vessel enlargement". Statistical analyses were performed using the chi-square test, analysis of variance (ANOVA), and rank test. The IAC prediction model was constructed via a multivariate logistical regression. Our prediction model for lung pGGNs was further validated in a data set comprising consecutive patients from multiple medical centers in China from July to December 2018. In total, 345 resected pGGNs were pathologically diagnosed as lung adenocarcinoma in the validation data set. RESULTS: In the training data set, patients with pGGNs ≥10 mm in size had a high incidence (74.5%) of IAC. The maximal CT value of IAC [-416.1±121.2 Hounsfield unit (HU)] was much higher than that of MIA (-507.7±138.0 HU) and AIS (-602.6±93.3 HU) (P<0.001). IAC was more common in pGGNs that displayed any of the following CT manifestations: lobulation, spiculation, pleura indentation, vacuole sign, and vessel abnormality. The IAC prediction model was constructed using the parameters that were assessed as risk factors (i.e., the nodule size, maximal CT value, and CT signs). The receiver operating characteristic (ROC) analysis showed that the area under the curve (AUC) of this model for diagnosing IAC was 0.910, which was higher than that of the AUC for nodule size alone (0.891) or the AUC for the maximal CT value alone (0.807) (P<0.05, respectively). A multicenter validation data set was used to validate the performance of our prediction model in diagnosing IAC, and our model was found to have an AUC of 0.883, which was higher than that of the AUC of 0.827 for the module size alone model or the AUC of 0.791 for the maximal CT value alone model (P<0.05, respectively). CONCLUSIONS: Our multi-parameter prediction model was more accurate at diagnosing IAC than models that used only nodule size or the maximal CT value alone. Thus, it is an efficient tool for identifying the IAC of malignant pGGNs and deciding if surgery is needed.

8.
ACS Appl Mater Interfaces ; 11(49): 46368-46378, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31714054

RESUMO

Humidity sensors have attracted intense interest in various fields because of the importance of humidity detection. Different methods have been adopted to enhance sensing performances of humidity sensors, while it is challenging for researchers to avoid the invalidation of the sensors after being wet. Here, we, for the first time, introduce self-assembly MoS2/Cu(OH)2 nanowires fabricated by liquid self-spreading-coating-evaporating as sensing materials and present MoS2/Cu(OH)2 nanowire-based quartz crystal microbalance gamut humidity sensors with superior sensitivity and self-recovery ability. The sensors deliver a remarkable sensitivity (60.8 Hz/% RH) under a wide range (0-97% RH) with fast response (1.9 s)/recovery time (3.8 s) and upgrade self-recovery ability that can maintain their original performances even after being wet, frozen, and heated or immersed in water. The sensors are also employed to monitor water counting, dew alarming, and human breathing (within 4 s), further showing their ultrahigh sensitivity for water molecules. The underlying humidity-sensing mechanism is interpreted by density functional theory calculations and in-situ Fourier transform infrared spectra experiments adequately, revealing that the high sensing performances are attributed to abundant adsorption sites and physisorption of water molecules. Our work proposes a strategy for transferring materials to arbitrary nanostructures swiftly and demonstrates new perspectives for highly sensitive humidity detection as well as self-recovery ability.

9.
Nanoscale Res Lett ; 13(1): 394, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30519820

RESUMO

We propose a novel one-step exposure method for fabricating three-dimensional (3D) suspended structures, utilizing the diffraction of mask patterns with small line width. An optical model of the exposure process is built, and the 3D light intensity distribution in the photoresist is calculated based on Fresnel-Kirchhoff diffraction formulation. Several 3D suspended photoresist structures have been achieved, such as beams, meshes, word patterns, and multilayer structures. After the pyrolysis of SU-8 structures, suspended and free-standing 3D carbon structures are further obtained, which show great potential in the application of transparent electrode, semitransparent solar cells, and energy storage devices.

10.
ACS Appl Mater Interfaces ; 10(51): 44815-44824, 2018 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-30461260

RESUMO

Water collection has been extensively researched due to its potential for mitigating the water scarcity in arid and semiarid regions. Numerous structures mimicking the fog-harvesting strategy of organisms have been fabricated for improving water-collecting efficiency. In this contribution, we demonstrate four-level wedge-shaped tracks inspired by leaf vein for enhancing directional water collection. Superhydrophilic Cu(OH)2 nanowires are introduced and prepared on flexible hydrophobic polyethylene terephthalate (PET) substrates by alkali-assisted surface oxidation at room temperature. They provide abundant capillary paths for promoting droplet absorption and forming water film tracks. Then, the hierarchical wedge-shaped tracks enable the water to be transported to a certain accumulation region spontaneously owing to the continuous Young-Laplace pressure difference. As a result, the four-level wedge-shaped tracks on PET substrate achieve the highest water-collecting efficiency, increasing by nearly 1150 and 510% compared to the bare PET and Cu(OH)2 nanowires on PET, respectively. After being bent for 105 cycles at a radius of 10 mm, the samples can still preserve high efficiency, indicating that the synthetic structures possess outstanding durability. Our approach provides a novel strategy for water collection and paves ways for directional liquid transportation and microfluidic devices.

11.
ACS Nano ; 8(7): 7163-9, 2014 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-24941287

RESUMO

We report the fabrication of quantum dot-sensitized hierarchical structure and the application of the structure as a photoanode for photoelectrochemical water splitting. The structure is synthesized by hydrothermally growing ZnO nanowires on silicon microwires grown with the vapor-liquid-solid method. Then the hierarchical structure is further sensitized with CdS and CdSe quantum dots and modified with IrOx quantum dots. As a result, the silicon microwires, ZnO nanowires, and the quantum dot/ZnO core/shell structure form a multiple-level hierarchical heterostructure, which is remarkably beneficial for light absorption and charge carrier separation. Our experimental results reveal that the photocurrent density of our multiple-level hierarchical structure achieves a surprising 171 times enhancement compared to that from simple ZnO nanowires on a planar substrate. In addition, the photoanode shows high stability during the water-splitting experiment. These results prove that the quantum dot-sensitized hierarchical structure is an ideal candidate for a photoanode in solar water splitting applications. Importantly, the modular design approach we take to produce the photoanode allows for the integration of future discoveries for further improvement of its performance.

12.
Cancer Epidemiol ; 37(3): 207-18, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23352629

RESUMO

PURPOSE: To assess the effect of metformin intake on cancer incidence and mortality. METHODS: Original articles in English published until June 15, 2012 were searched for in electronic databases (MEDLINE, ISI Web of Science and EMBASE databases) and relevant reviews were examined. Meta-analysis was applied to calculate the summary relative risk (SRR) and their 95% confidence intervals (95% CI). Sensitivity analysis was conducted to assess the robustness of the pooled estimator. The risk of publication bias was assessed by the Egger regression asymmetry test. RESULTS: According to the eligibility criteria, 37 studies comprising 1,535,636 participants, were selected in terms of intervention and data of cancer incidence or mortality. Among metformin users compared with non-users, the SRR for overall-cancer incidence was 0.73 (95% CI, 0.64-0.83) and that for mortality was 0.82 (95% CI, 0.76-0.89). The risk reductions for liver, pancreatic, colorectal and breast cancer incidence were 78%, 46%, 23% and 6%, respectively. Also, metformin can reduce the mortality of liver cancer (SRR, 0.23; 95% CI, 0.09-0.60) and breast cancer (SRR, 0.63; 95% CI, 0.40-0.99). No statistically significant association between metformin and prostate cancer incidence was found. CONCLUSIONS: Metformin can reduce the incidence of overall cancer, liver cancer, pancreatic cancer, colorectal cancer and breast cancer as well as the mortality of overall cancer, liver cancer and breast cancer. No beneficial effect on prostate cancer incidence was found for meformin intake in the meta-analysis.


Assuntos
Hipoglicemiantes/administração & dosagem , Metformina/administração & dosagem , Neoplasias/epidemiologia , Humanos , Incidência , Neoplasias/mortalidade , Taxa de Sobrevida
13.
Zhonghua Liu Xing Bing Xue Za Zhi ; 25(6): 527-30, 2004 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-15231138

RESUMO

OBJECTIVE: To explore the risk factors of Parkinson disease (PD), interaction between family history of PD and other risk factors, as well as the relative strength of genetic factors over the vulnerability of PD. METHODS: One 1:1 matched case-control study including 157 pairs of cases and controls was conducted in Qilu Hospital of Shandong University. RESULTS: Conditional logistic regression analysis showed that family history of PD, mental labor, insecticide, alcohol drinking and history of depression all had positive relationship, while smoking had a negative relationship with PD. The AP (AB)s of family history of PD and insecticide, alcohol drinking, history of depression were 55.2%, 34.0%, 41.4% and the RERIs were 8.96, 3.31, 7.85 respectively. The heritability of PD patients' first degree relatives was 36.86% +/- 5.76%, and second degree relatives was 20.66% +/- 6.81%. CONCLUSION: Family history of PD had an additive model synergism on PD, coexisting with other risk factors. Genetic factors had a smaller action on PD than environmental factors.


Assuntos
Doença de Parkinson/etiologia , Doença de Parkinson/genética , Adulto , Consumo de Bebidas Alcoólicas/efeitos adversos , Estudos de Casos e Controles , Intervalos de Confiança , Saúde da Família , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Linhagem , Praguicidas/efeitos adversos , Modelos de Riscos Proporcionais , Fatores de Risco , Fumar/efeitos adversos , Inquéritos e Questionários
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA