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1.
Clin Immunol ; 266: 110309, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-39002795

RESUMO

Psoriasis is a common inflammatory systemic disease characterized by pro-inflammatory macrophages activation (M1 macrophage) infiltrated in the dermal layer. How M1 macrophage contributes to psoriasis remains unknown. In this study, we found that adenosine A2A receptor (A2AR) agonist CGS 21680 HCl alleviated the imiquimod (IMQ) and mouse IL-23 Protein (rmIL-23)-induced psoriasis inflammation through reducing infiltration of M1. Conversely, Adora2a deletion in mice exacerbated psoriasis-like phenotype. Mechanistically, A2AR activation inhibited M1 macrophage activation via the NF-κB-KRT16 pathway to reduce the secretion of CXCL10/11 and inhibit Th1/17 differentiation. Notably, the KRT16 expression was first found in M1 macrophage in our study, not only in keratinocytes (KCs). CXCL10/11 are first identified as primarily derived from macrophages and dendritic cells (DCs) rather than KCs in psoriasis using single cell RNA sequencing (scRNA-Seq). In total, the study emphasizes the importance of M1 as an innate immune cell in pathogenesis of psoriasis.

2.
Sensors (Basel) ; 24(7)2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38610490

RESUMO

On-orbit assembling space telescope (OAST) is one of the most feasible methods to implement a large-scale space telescope. Unlike a monolithic space telescope (such as Hubble Space Telescope, HST) or a deployable space telescope (such as James Webb Space Telescope, JWST), OAST can be assembled in the spatial environment. To ensure proper telescope performance, OAST must be equipped with a large deployable sunshade. In order to verify the technology of the OAST, the authors propose a modular space telescope on the China Space Station (CSS) and design a deployable sunshade. The deployable mechanism of the sunshade is made up of a radial deployable mechanism and an axial deployable mechanism. The paper describes the overall design approach, the key component technologies, and the design and preliminary testing of a part of the deployable sunshade assembly.

3.
Inorg Chem ; 62(27): 10805-10821, 2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37364168

RESUMO

Agile and efficient upconversion luminescence (UCL) fine-tuning strategies are the most demanded for in the frontier applications of highly doped upconversion nanoparticles (UCNPs). By doping Zn2+ ions into NaHoF4 and NaGdF4:Yb3+ shells using the oleate method, the separate influences of Zn2+ on Ho3+ and Yb3+ ions in UCL-related processes were analyzed in detail, revealing relevant UCL changes and underlying energy mechanisms from a novel but explicit perspective. Different behaviors of green and red UCL before and after Zn2+-ion doping were attributed to the disparities in the energy pathways and features of the sample structures. Herein, the populations of 5S2/5F4 and 5F5 states, not the usually mentioned decay time, decided the UCL intensities of the NaHoF4@NaYbF4-structured highly doped UCNPs. The advantageous small sizes and intense single-band red UCL of these UCNPs were further developed by combining our previous strategies with introducing Zn2+ ions into the NaHoF4 matrix. Overcoming energy loss by surface quenchers and Zn2+-triggered inner defects is the key factor in maximizing 4f-4f transitions. To the best of our knowledge, the current study is the first attempt to date to experimentally reveal separate impacts of the heteroions on activators and sensitizers in UCL-related processes and can deepen the theoretical investigation of Ho-based UCL for the broadened applications of NaHoF4 UCNPs.

4.
Gen Physiol Biophys ; 42(4): 361-372, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37449320

RESUMO

Hypertrophic cardiomyopathy (HCM) is a primary cardiomyopathy characterized by hypertrophic cardiomyocytes. It is one of the leading causes of sudden death in adolescents. However, the molecular mechanism of HCM is not clear. In our study, ribonucleic acid (RNA) sequence data of myocardial tissue in HCM patients were extracted from the Gene Expression Omnibus (GEO) database (GSE130036) and analyzed by weighted gene coexpression network analysis (WGCNA). A total of 31 coexpression modules were identified. The coexpression black module significantly correlated with maximum left ventricular wall thickness (Maxi LVWT). We screened the differentially expressed mRNAs between normal tissues and HCM tissues using the dplyr and tidyr packages in R3.6.2. The genes in the black module and differentially expressed genes were further intersected. We found that the expression of carboxylesterase 1 (CES1) and cathepsin C (CTSC) was downregulated in HCM tissues and negatively correlated with Maxi LVWT. We further verified the expression of CES1 and CTSC was downregulated in HCM clinical blood and negatively correlated with Maxi LVWT. Finally, we demonstrated that overexpression of CTSC and CES1 could alleviate HCM in an HCM cell model. In summary, the study suggests that CES1 and CTSC negatively regulate the development of HCM and have potential as therapeutic and diagnostic targets for HCM.


Assuntos
Cardiomiopatia Hipertrófica , Catepsina C , Adolescente , Humanos , Catepsina C/genética , Cardiomiopatia Hipertrófica/genética , Miocárdio , Redes Reguladoras de Genes/genética , Hidrolases de Éster Carboxílico/genética
5.
J Environ Sci (China) ; 132: 83-97, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37336612

RESUMO

Daytime HONO photolysis is an important source of atmospheric hydroxyl radicals (OH). Knowledge of HONO formation chemistry under typical haze conditions, however, is still limited. In the Multiphase chemistry experiment in Fogs and Aerosols in the North China Plain in 2018, we investigated the wintertime HONO formation and its atmospheric implications at a rural site Gucheng. Three different episodes based on atmospheric aerosol loading levels were classified: clean periods (CPs), moderately polluted periods (MPPs) and severely polluted periods (SPPs). Correlation analysis revealed that HONO formation via heterogeneous conversion of NO2 was more efficient on aerosol surfaces than on ground, highlighting the important role of aerosols in promoting HONO formation. Daytime HONO budget analysis indicated a large missing source (with an average production rate of 0.66 ± 0.26, 0.97 ± 0.47 and 1.45 ± 0.55 ppbV/hr for CPs, MPPs and SPPs, respectively), which strongly correlated with photo-enhanced reactions (NO2 heterogeneous reaction and particulate nitrate photolysis). Average OH formation derived from HONO photolysis reached up to (0.92 ± 0.71), (1.75 ± 1.26) and (1.82 ± 1.47) ppbV/hr in CPs, MPPs and SPPs respectively, much higher than that from O3 photolysis (i.e., (0.004 ± 0.004), (0.006 ± 0.007) and (0.0035 ± 0.0034) ppbV/hr). Such high OH production rates could markedly regulate the atmospheric oxidation capacity and hence promote the formation of secondary aerosols and pollutants.


Assuntos
Poluentes Ambientais , Ácido Nitroso , Ácido Nitroso/análise , Poluentes Ambientais/análise , Dióxido de Nitrogênio/análise , China , Aerossóis/análise
6.
Appl Environ Microbiol ; 88(13): e0043722, 2022 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-35736228

RESUMO

The amino sugar N-acetyl-d-glucosamine (GlcNAc) is the key constituent of cell wall components and plays an important role in pathogenesis in a wide range of fungi. However, catabolism of GlcNAc has not been studied in basidiomycete fungi. In this study, we identified and characterized a gene cluster essential for GlcNAc utilization in Cryptococcus deneoformans, an environmental human fungal pathogen. The C. deneoformans genome contains a GlcNAc transporter (Ngt1), a GlcNAc kinase (Hxk3), a GlcNAc-6-phosphate deacetylase (Dac1), and a glucosamine-6-phosphate deaminase (Nag1). Their expression levels were highly induced in cultures containing GlcNAc as the sole carbon source, and the corresponding mutants showed severe growth defects in the presence of GlcNAc. Functional and biochemical analyses revealed that HXK3 encodes a novel GlcNAc kinase. Site-directed mutations of conserved residues of Hxk3 indicated that ATP binding and GlcNAc binding are essential for GlcNAc kinase activities. Taken together, the results from this study provide crucial insights into basidiomycete GlcNAc catabolism. IMPORTANCEN-Acetylglucosamine (GlcNAc) is recognized as not only the building block of chitin but also an important signaling molecule in fungi. The catabolic pathway of GlcNAc also plays an important role in vital biological processes in fungi. However, the utilization pathway of GlcNAc in the phylum Basidiomycota, which contains more than 41,000 species, remains unknown. Cryptococcus deneoformans is a representative basidiomycetous pathogen that causes life-threatening meningitis. In this study, we characterized a gene cluster essential for GlcNAc utilization in C. deneoformans and identified a novel GlcNAc kinase. The results of this study provide important insights into basidiomycete GlcNAc catabolism and offer a starting point for revealing its role in pathogenesis.


Assuntos
Candida albicans , Cryptococcus , Acetilglucosamina/metabolismo , Parede Celular/metabolismo , Quitina/metabolismo , Humanos
7.
Faraday Discuss ; 226: 207-222, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33284304

RESUMO

Fine-particle pollution associated with winter haze threatens the health of more than 400 million people in the North China Plain. The Multiphase chemistry experiment in Fogs and Aerosols in the North China Plain (McFAN) investigated the physicochemical mechanisms leading to haze formation with a focus on the contributions of multiphase processes in aerosols and fogs. We integrated observations on multiple platforms with regional and box model simulations to identify and characterize the key oxidation processes producing sulfate, nitrate and secondary organic aerosols. An outdoor twin-chamber system was deployed to conduct kinetic experiments under real atmospheric conditions in comparison to literature kinetic data from laboratory studies. The experiments were spanning multiple years since 2017 and an intensive field campaign was performed in the winter of 2018. The location of the site minimizes fast transition between clean and polluted air masses, and regimes representative for the North China Plain were observed at the measurement location in Gucheng near Beijing. The consecutive multi-year experiments document recent trends of PM2.5 pollution and corresponding changes of aerosol physical and chemical properties, enabling in-depth investigations of established and newly proposed chemical mechanisms of haze formation. This study is mainly focusing on the data obtained from the winter campaign 2018. To investigate multiphase chemistry, the results are presented and discussed by means of three characteristic cases: low humidity, high humidity and fog. We find a strong relative humidity dependence of aerosol chemical compositions, suggesting an important role of multiphase chemistry. Compared with the low humidity period, both PM1 and PM2.5 show higher mass fraction of secondary inorganic aerosols (SIA, mainly as nitrate, sulfate and ammonium) and secondary organic aerosols (SOA) during high humidity and fog episodes. The changes in aerosol composition further influence aerosol physical properties, e.g., with higher aerosol hygroscopicity parameter κ and single scattering albedo SSA under high humidity and fog cases. The campaign-averaged aerosol pH is 5.1 ± 0.9, of which the variation is mainly driven by the aerosol water content (AWC) concentrations. Overall, the McFAN experiment provides new evidence of the key role of multiphase reactions in regulating aerosol chemical composition and physical properties in polluted regions.

8.
Environ Sci Technol ; 55(6): 3568-3581, 2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33656863

RESUMO

Peroxyacetyl nitrate (PAN) is an important indicator for photochemical pollution, formed similar to ozone in the photochemistry of certain volatile organic compounds (VOCs) in the presence of nitrogen oxides, and has displayed surprisingly high concentrations during wintertime that were better correlated to particulate rather than ozone concentrations, for which the reasons remained unknown. In this study, wintertime observations of PAN, VOCs, PM2.5, HONO, and various trace gases were investigated to find the relationship between aerosols and wintertime PAN formation. Wintertime photochemical pollution was affirmed by the high PAN concentrations (average: 1.2 ± 1.1 ppb, maximum: 7.1 ppb), despite low ozone concentrations. PAN concentrations were determined by its oxygenated VOC (OVOC) precursor concentrations and the NO/NO2 ratios and can be well parameterized based on the understanding of their chemical relationship. Data analysis and box modeling results suggest that PAN formation was mostly contributed by VOC aging processes involving OH oxidation or photolysis rather than ozonolysis pathways. Heterogeneous reactions on aerosols have supplied key photochemical oxidants such as HONO, which produced OH radicals upon photolysis, promoting OVOC formation and thereby enhancing PAN production, explaining the observed PM2.5-OVOC-PAN intercorrelation. In turn, parts of these OVOCs might participate in the formation of secondary organic aerosol, further aggravating haze pollution as a feedback. Low wintertime temperatures enable the long-range transport of PAN to downwind regions, and how that will impact their oxidation capacity and photochemical pollution requires further assessment in future studies.


Assuntos
Poluentes Atmosféricos , Ozônio , Aerossóis , Poluentes Atmosféricos/análise , China , Monitoramento Ambiental , Ozônio/análise , Ácido Peracético/análogos & derivados
9.
Anal Chem ; 92(1): 1635-1642, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31834785

RESUMO

A visual assay for the detection of heparinase was developed on the basis of a ternary system of Hg2+-heparin-osmium nanoparticles (OsNPs). First, heparin-capped OsNPs (heparin-OsNPs) were synthesized by a facile reduction method using heparin as the protecting/stabilizing agent. The oxidase-like activity of heparin-OsNPs, however, turned out to be low, which somewhat limits their application. We discovered that Hg2+ can significantly/specifically boost the oxidase-like activity of heparin-OsNPs via electrostatic interaction. The oxidase-like activity of heparin-OsNPs toward the oxidation of the substrate, 3,3',5,5'-tetramethylbenzidine, by dissolved O2 was found to increase by 76-fold in the presence of Hg2+. More significantly, heparin in heparin-OsNPs could be specifically hydrolyzed into small fragments in the presence of heparinase, which resulted in the weakening of the oxidase-like activity of Hg2+/heparin-OsNPs. On the basis of these findings, a linear response of the sensor for heparinase was obtained in the range 20-1000 µg/L with a low detection limit (15 µg/L), which is comparable to those of other reported sensors. Further, the colorimetric sensor was employed for the detection of heparinase in human serum samples with satisfactory results. We speculate that combining such surface modification of the osmium nanozyme with a sensing element could be an interesting direction for promoting nanozyme research in medical diagnosis.


Assuntos
Heparina Liase/análise , Heparina/química , Mercúrio/química , Nanopartículas Metálicas/química , Osmio/química , Técnicas Biossensoriais , Heparina Liase/metabolismo , Humanos , Estrutura Molecular
10.
Small ; 16(43): e2003799, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33006248

RESUMO

It is absolutely imperative for development of material science to adjust upconversion luminescence (UCL) properties of highly doped upconversion nanoparticles (UCNPs) with special optical properties and prominent application prospects. In this work, featuring NaHoF4 @NaYbF4 (Ho@Yb) structures, sub-30 nm core-multishell UCNPs are synthesized with a small NaHoF4 core and varied Gd3+ /Yb3+ coexisting shells. X-ray diffraction, transmission electron microscopy, UCL spectrum, UCL lifetime, and pump power dependence are adhibited for characterization. Compared with the former work, except for a smaller total size, tunable emission in color from red to yellow to green, and intensity from low to stronger than that of traditional UCNPs is achieved for ≈10 nm NaHoF4 core size by means of changing number of layers and Gd3+ /Yb3+ concentration ratios in different layers. Besides, simultaneously doping Ho3+ into the shells will result in lowered UCL intensity and lifted green/red ratio. Surface energy loss and sensitizing energy supply, which can be modulated with inert shielding of Gd3+ and sensitization of Yb3+ , are proved to be the essential determinant. More UCL properties of these peculiar Ho@Yb UCNPs are uncovered and detailedly summarized, and the findings can help to expand the application scope of NaHoF4 into photoinduced therapy.

11.
Opt Express ; 28(1): 130-145, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-32118945

RESUMO

Potential advantages offered by multichannel luminaires with regards to spectral tuning are frequently overshadowed by its design challenges, a major one being the non-uniformity in illuminance and color distribution. In this paper, we present a formulation using genetic algorithm (GA) to optimize the Light Emitting Diode (LED) placement, yielding 40% superior uniformity in illuminance and color distributions compared to existing analytical formulations, substantially reducing the reliance on optical design for this purpose. It is specifically shown that our approach is employable for circadian tuning applications, even when heavily constrained by industry specifications on panel size and minimum LED separation.

12.
Environ Sci Technol ; 54(24): 15710-15721, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33237756

RESUMO

Secondary aerosol (SA) frequently drives severe haze formation on the North China Plain. However, previous studies mostly focused on submicron SA formation, thus our understanding of SA formation on supermicron particles remains poor. In this study, PM2.5 chemical composition and PM10 number size distribution measurements revealed that the SA formation occurred in very distinct size ranges. In particular, SA formation on dust-dominated supermicron particles was surprisingly high and increased with relative humidity (RH). SA formed on supermicron aerosols reached comparable levels with that on submicron particles during evolutionary stages of haze episodes. These results suggested that dust particles served as a medium for rapid secondary organic and inorganic aerosol formation under favorable photochemical and RH conditions in a highly polluted environment. Further analysis indicated that SA formation pathways differed among distinct size ranges. Overall, our study highlights the importance of dust in SA formation during non-dust storm periods and the urgent need to perform size-resolved aerosol chemical and physical property measurements in future SA formation investigations that are extended to the coarse mode because the large amount of SA formed thereon might have significant impacts on ice nucleation, radiative forcing, and human health.


Assuntos
Poluentes Atmosféricos , Poeira , Aerossóis/análise , Poluentes Atmosféricos/análise , China , Poeira/análise , Monitoramento Ambiental , Humanos , Tamanho da Partícula , Material Particulado/análise , Estações do Ano
13.
Environ Sci Technol ; 54(7): 3849-3860, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32131584

RESUMO

Secondary organic aerosol (SOA) constitutes a large fraction of organic aerosol worldwide, however, the formation mechanisms in polluted environments remain poorly understood. Here we observed fast daytime growth of oxygenated organic aerosol (OOA) (with formation rates up to 10 µg m-3 h-1) during low relative humidity (RH, daytime average 38 ± 19%), high RH (53 ± 19%), and fog periods (77 ± 13%, fog occurring during nighttime with RH reaching 100%). Evidence showed that photochemical aqueous-phase SOA (aqSOA) formation dominantly contributed to daytime OOA formation during the periods with nighttime fog, while both photochemical aqSOA and gas-phase SOA (gasSOA) formation were important during other periods with the former contributing more under high RH and the latter under low RH conditions, respectively. Compared to daytime photochemical aqSOA production, dark aqSOA formation was only observed during the fog period and contributed negligibly to the increase in OOA concentrations due to fog scavenging processes. The rapid daytime aging, as indicated by the rapid decrease in m,p-xylene/ethylbenzene ratios, promoted the daytime formation of precursors for aqSOA formation, e.g., carbonyls such as methylglyoxal. Photooxidants related to aqSOA formation such as OH radical and H2O2 also bear fast daytime growth features even under low solar radiative conditions. The simultaneous increases in ultraviolet radiation, photooxidant, and aqSOA precursor levels worked together to promote the daytime photochemical aqSOA formation. We also found that biomass burning emissions can promote photochemical aqSOA formation by adding to the levels of aqueous-phase photooxidants and aqSOA precursors. Therefore, future mitigation of air pollution in a polluted environment would benefit from stricter control on biomass burning especially under high RH conditions.


Assuntos
Poluentes Atmosféricos , Aerossóis , China , Peróxido de Hidrogênio , Raios Ultravioleta
14.
Environ Sci Technol ; 54(19): 11818-11826, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32876440

RESUMO

Isocyanic acid (HNCO) is a potentially toxic atmospheric pollutant, whose atmospheric concentrations are hypothesized to be linked to adverse health effects. An earlier model study estimated that concentrations of isocyanic acid in China are highest around the world. However, measurements of isocyanic acid in ambient air have not been available in China. Two field campaigns were conducted to measure isocyanic acid in ambient air using a high-resolution time-of-flight chemical ionization mass spectrometer (ToF-CIMS) in two different environments in China. The ranges of mixing ratios of isocyanic acid are from below the detection limit (18 pptv) to 2.8 ppbv (5 min average) with the average value of 0.46 ppbv at an urban site of Guangzhou in the Pearl River Delta (PRD) region in fall and from 0.02 to 2.2 ppbv with the average value of 0.37 ppbv at a rural site in the North China Plain (NCP) during wintertime, respectively. These concentrations are significantly higher than previous measurements in North America. The diurnal variations of isocyanic acid are very similar to secondary pollutants (e.g., ozone, formic acid, and nitric acid) in PRD, indicating that isocyanic acid is mainly produced by secondary formation. Both primary emissions and secondary formation account for isocyanic acid in the NCP. The lifetime of isocyanic acid in a lower atmosphere was estimated to be less than 1 day due to the high apparent loss rate caused by deposition at night in PRD. Based on the steady state analysis of isocyanic acid during the daytime, we show that amides are unlikely enough to explain the formation of isocyanic acid in Guangzhou, calling for additional precursors for isocyanic acid. Our measurements of isocyanic acid in two environments of China provide important constraints on the concentrations, sources, and sinks of this pollutant in the atmosphere.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , China , Cianatos/análise , Monitoramento Ambiental , América do Norte
15.
Biomacromolecules ; 20(6): 2207-2217, 2019 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-31042021

RESUMO

A quadruplex-integrated assembly method is proposed for the organization and regulation of various nanoscale architectures. In this method, two types of one-dimensional DNA nanostructures formed by two well-designed GC-rich single strands assemble into two-dimensional (2D) DNA nanostructures based on the self-assembly of dimeric G-quadruplex and I-motif structures. Subsequently, a C-rich strand and two biotin-modified G-rich strands primordially form a notched double helix in LiCl solution (pH 8). However, a linear "DNA-protein" nanostructure linked by I-motif structures and biotin-streptavidin interaction can be formed when hydrogen ions and streptavidin are sequentially titrated. Furthermore, the linear "DNA-protein" nanostructure is assembled into 2D nanomaterials connected by K+-stabilized G-quadruplexes formed from terminal G-rich repeats of the two G-rich strands. Interestingly, the 2D nanohybrids form two-lined "DNA-protein" nanostructures if the terminal G-rich repeats in one of the biotin-modified G-rich strands are removed. Our results indicate that quadruplex DNAs are promising building blocks in the fabrication of nanomaterials and that the assembly of quadruplex DNAs has potential applications in the directional arrangement of macromolecules.


Assuntos
DNA/química , Quadruplex G , Nanoestruturas/química
16.
J Nanosci Nanotechnol ; 18(6): 3759-3774, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442708

RESUMO

Magnetic resonance imaging is a powerful diagnostic technology with high spatial resolution and non-invasion. The contrast agents have significant effect on the resolution of the MR imaging. However, the commercial contrast agents (CAs) usually consist of individual Gd3+ chelated with a low molecular weight acyclic or cyclic ligand, and these small-molecule CAs are usually subjected to nonspecificity, thus leading to rapid renal clearance and modest contrast enhancement for tumor imaging. In recent years, the nanostructured materials conjugated with aptamers were widely used and opened a new door in biomedical imaging due to excellent specificity, non-immunogenicity, easily synthesis and chemical modification of aptamers. This review summarizes all kinds of aptamertargeted MRI CAs and their applications.


Assuntos
Meios de Contraste , Imageamento por Ressonância Magnética , Oligonucleotídeos , Nanoestruturas , Neoplasias
17.
Int J Mol Sci ; 19(6)2018 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-29857490

RESUMO

Chemical injury is partly due to free radical lipid peroxidation, which can induce oxidative stress and produce a large number of reactive oxygen species (ROS). Oxaloacetic acid is an important intermediary in the tricarboxylic acid cycle (TCA cycle) and participates in metabolism and energy production. In our study, we found that oxaloacetate (OA) effectively alleviated liver injury which was induced by hydrogen peroxide (H2O2) in vitro and carbon tetrachloride (CCl4) in vivo. OA scavenged ROS, prevented oxidative damage and maintained the normal structure of mitochondria. We further confirmed that OA increased adenosine triphosphate (ATP) by promoting the TCA production cycle and oxidative phosphorylation (OXPHOS). Finally, OA inhibited the mitogen-activated protein kinase (MAPK) and apoptotic pathways by suppressing tumor necrosis factor-α (TNF-α). Our findings reveal a mechanism for OA ameliorating chemical liver injury and suggest a possible implementation for preventing the chemical liver injury.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Metabolismo Energético/efeitos dos fármacos , Ácido Oxaloacético/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Tetracloreto de Carbono/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Ciclo do Ácido Cítrico/efeitos dos fármacos , Modelos Animais de Doenças , Glicólise , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Camundongos , Mitocôndrias/metabolismo , Modelos Biológicos , Fosforilação Oxidativa/efeitos dos fármacos , Substâncias Protetoras/farmacologia
18.
Opt Lett ; 42(22): 4607-4610, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-29140324

RESUMO

Aerosol optical depth (AOD) is a crucial parameter in describing the atmospheric pollution and analyzing the influences of aerosol on the radiative equilibrium. Currently, no method can precisely and continuously measure the nocturnal AOD. In this study, a novel method was developed to retrieve the nocturnal AOD based on a remote sensing instrument called the charge-coupled device-laser aerosol detective system (CCD-LADS). CCD-LADS consists of a CCD camera, a continuous laser, a fisheye lens, and related filters. The AOD can be calculated by integrating the aerosol extinction coefficient profile retrieved from CCD-LADS measurements. The retrieved AOD was validated with AERONET and MODIS data sets. The comparison shows good agreement.

19.
Biomacromolecules ; 18(1): 150-158, 2017 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-28064499

RESUMO

There was much interest in the development of nanoscale delivery vehicles based on polymeric micelles to realize the diagnostic and therapeutic applications in biomedicine. Here, with the purpose of constructing a micellar magnetic resonance imaging (MRI) contrast agent (CA) with well biocompatibility and targeting specificity, two types of amphiphilic diblock polymers, mPEG-PG(DOTA(Gd))-b-PCL and FA-PEG-b-PCL, were synthesized to form mixed micelles by coassembly. The nanostructure of the resulting micellar system consisted of poly(caprolactone) (PCL) as core and poly(glycerol) (PG) and poly(ethylene glycol) (PEG) as shell, simultaneously modified with DOTA(Gd) chelates and folic acid (FA), which afforded functions of MRI contrast enhancement and tumor targeting. The mixed micelles in aqueous solution presented a hydrodynamic diameter of about 85 nm. Additionally, this mixed micelles exhibited higher r1 relaxivity (14.01 mM-1 S1-) compared with commercial Magnevist (3.95 mM-1 S1-) and showed negligible cytotoxicity estimated by WST assay. In vitro and in vivo MRI experiments revealed excellent targeting specificity to tumor cells and tissue. Furthermore, considerably enhanced signal intensity and prominent positive contrast effect were achieved at tumor region after tumor-bearing mice were intravenously injected with the mixed micelles. These preliminary results indicated the potential of the mixed micelle as T1 MRI CA for tumor-targeted imaging.


Assuntos
Meios de Contraste/metabolismo , Glicerol/química , Imageamento por Ressonância Magnética/métodos , Micelas , Neoplasias Bucais/diagnóstico por imagem , Polímeros/administração & dosagem , Animais , Sobrevivência Celular/efeitos dos fármacos , Feminino , Ácido Fólico/metabolismo , Humanos , Células KB , Camundongos , Camundongos Nus , Neoplasias Bucais/metabolismo , Neoplasias Bucais/patologia , Polímeros/química , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Sensors (Basel) ; 17(9)2017 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-28885555

RESUMO

Inertial sensors are widely used in various applications, such as human motion monitoring and pedestrian positioning. However, inertial sensors cannot accurately define the process of human movement, a limitation that causes data drift in the process of human body positioning, thus seriously affecting positioning accuracy and stability. The traditional pedestrian dead-reckoning algorithm, which is based on a single inertial measurement unit, can suppress the data drift, but fails to accurately calculate the number of walking steps and heading value, thus it cannot meet the application requirements. This study proposes an indoor dynamic positioning method with an error self-correcting function based on the symmetrical characteristics of human motion to obtain the definition basis of human motion process quickly and to solve the abovementioned problems. On the basis of this proposed method, an ultra-wide band (UWB) method is introduced. An unscented Kalman filter is applied to fuse inertial sensors and UWB data, inertial positioning is applied to compensation for the defects of susceptibility to UWB signal obstacles, and UWB positioning is used to overcome the error accumulation of inertial positioning. The above method can improve both the positioning accuracy and the response of the positioning results. Finally, this study designs an indoor positioning test system to test the static and dynamic performances of the proposed indoor positioning method. Results show that the positioning system both has high accuracy and good real-time performance.


Assuntos
Algoritmos , Movimento (Física) , Pedestres , Humanos , Caminhada
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