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1.
Small ; : e2401204, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38801305

RESUMO

The demand for state-of-the-art high-energy-density lithium-ion batteries is increasing. However, the low specific capacity of electrode materials in conventional full-cell systems cannot meet the requirements. Ni-rich layered oxide cathodes such as Li(Ni0.8Co0.1Mn0.1)O2 (NCM811) have a high theoretical specific capacity of 200 mAh g-1, but it is always accompanied by side reactions on the electrode/electrolyte interface. Phosphorus anode possesses a high theoretical specific capacity of 2596 mAh g-1, but it has a huge volume expansion (≈300%). Herein, a highly compatible and secure electrolyte is reported via introducing an additive with a narrow electrochemical window, Lithium difluoro(oxalato)borate (LiDFOB), into 1 m LiPF6 EC/DMC with tris (2,2,2-trifluoroethyl) phosphate (TFEP) as a cosolvent. LiDFOB participates in the formation of organic/inorganic hybrid electrode/electrolyte interface layers at both the cathode and anode sides. The side reactions on the surface of the NCM811 cathode and the volume expansion of the phosphorus anode are effectively alleviated. The NCM811//RP full cell in this electrolyte shows high capacity retention of 82% after 150 cycles at a 0.5C rate. Meanwhile, the electrolyte shows non-flammability. This work highlights the importance of manipulating the electrode/electrolyte interface layers for the design of lithium-ion batteries with high energy density.

2.
Microb Cell Fact ; 23(1): 153, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38796416

RESUMO

BACKGROUND: Dihydroxyacetone (DHA) stands as a crucial chemical material extensively utilized in the cosmetics industry. DHA production through the dephosphorylation of dihydroxyacetone phosphate, an intermediate product of the glycolysis pathway in Escherichia coli, presents a prospective alternative for industrial production. However, insights into the pivotal enzyme, dihydroxyacetone phosphate dephosphorylase (HdpA), remain limited for informed engineering. Consequently, the development of an efficient tool for high-throughput screening of HdpA hypermutants becomes imperative. RESULTS: This study introduces a methylglyoxal biosensor, based on the formaldehyde-responding regulator FrmR, for the selection of HdpA. Initial modifications involved the insertion of the FrmR binding site upstream of the -35 region and into the spacer region between the -10 and -35 regions of the constitutive promoter J23110. Although the hybrid promoter retained constitutive expression, expression of FrmR led to complete repression. The addition of 350 µM methylglyoxal promptly alleviated FrmR inhibition, enhancing promoter activity by more than 40-fold. The methylglyoxal biosensor system exhibited a gradual increase in fluorescence intensity with methylglyoxal concentrations ranging from 10 to 500 µM. Notably, the biosensor system responded to methylglyoxal spontaneously converted from added DHA, facilitating the separation of DHA producing and non-producing strains through flow cytometry sorting. Subsequently, the methylglyoxal biosensor was successfully applied to screen a library of HdpA mutants, identifying two strains harboring specific mutants 267G > T and D110G/G151C that showed improved DHA production by 68% and 114%, respectively. Expressing of these two HdpA mutants directly in a DHA-producing strain also increased DHA production from 1.45 to 1.92 and 2.29 g/L, respectively, demonstrating the enhanced enzyme properties of the HdpA mutants. CONCLUSIONS: The methylglyoxal biosensor offers a novel strategy for constructing genetically encoded biosensors and serves as a robust platform for indirectly determining DHA levels by responding to methylglyoxal. This property enables efficiently screening of HdpA hypermutants to enhance DHA production.


Assuntos
Técnicas Biossensoriais , Di-Hidroxiacetona , Escherichia coli , Aldeído Pirúvico , Aldeído Pirúvico/metabolismo , Técnicas Biossensoriais/métodos , Di-Hidroxiacetona/metabolismo , Escherichia coli/metabolismo , Escherichia coli/genética , Regiões Promotoras Genéticas , Engenharia Metabólica/métodos , Proteínas de Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética
3.
BMC Musculoskelet Disord ; 25(1): 478, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890605

RESUMO

BACKGROUND: The aim of the study was to investigate the muscle differences in children with osteogenesis imperfecta (OI) using opportunistic low-dose chest CT and to compare different methods for the segmentation of muscle in children. METHODS: This single center retrospective study enrolled children with OI and controls undergoing opportunistic low-dose chest CT obtained during the COVID pandemic. From the CT images, muscle size (cross-sectional area) and density (mean Hounsfield Units [HU]) of the trunk muscles were measured at the mid-T4 and the mid-T10 level using two methods, the fixed thresholds and the Gaussian mixture model. The Bland-Altman method was also used to compute the strength of agreement between two methods. Comparison of muscle results between OI and controls were analyzed with Student t tests. RESULTS: 20 children with OI (mean age, 9.1 ± 3.3 years, 15 males) and 40 age- and sex-matched controls were enrolled. Mean differences between two methods were good. Children with OI had lower T4 and T10 muscle density than controls measured by the fixed thresholds (41.2 HU vs. 48.0 HU, p < 0.01; 37.3 HU vs. 45.9 HU, p < 0.01). However, children with OI had lower T4 muscle size, T4 muscle density, T10 muscle size and T10 muscle density than controls measured by the Gaussian mixture model (110.9 vs. 127.2 cm2, p = 0.03; 44.6 HU vs. 51.3 HU, p < 0.01; 72.6 vs. 88.0 cm2, p = 0.01; 41.6 HU vs. 50.3 HU, p < 0.01, respectively). CONCLUSIONS: Children with OI had lower trunk muscle density indicating that OI might also impair muscle quality. Moreover, the fixed thresholds may not be suitable for segmentation of muscle in children.


Assuntos
Músculo Esquelético , Osteogênese Imperfeita , Tomografia Computadorizada por Raios X , Humanos , Osteogênese Imperfeita/diagnóstico por imagem , Masculino , Feminino , Criança , Estudos Retrospectivos , Estudos de Casos e Controles , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/patologia , Adolescente , COVID-19/diagnóstico por imagem , Doses de Radiação , Pré-Escolar
4.
Microb Ecol ; 85(3): 904-915, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35650293

RESUMO

Thermokarst lakes have long been recognized as biogeochemical hotspots, especially as sources of greenhouse gases. On the Qinghai-Tibet Plateau, thermokarst lakes are experiencing extensive changes due to faster warming. For a deep understanding of internal lake biogeochemical processes, we applied metagenomic analyses to investigate the microbial diversity and their biogeochemical roles in sediment and water of thermokarst lakes in the Yellow River Source Area (YRSA). Sediment microbial communities (SMCs) had lower species and gene richness than water microbial communities (WMCs). Bacteria were the most abundant component in both SMCs and WMCs with significantly different abundant genera. The functional analyses showed that both SMCs and WMCs had low potential in methanogenesis but strong in aerobic respiration, nitrogen assimilation, exopolyphosphatase, glycerophosphodiester phosphodiesterases, and polyphosphate kinase. Moreover, SMCs were enriched in genes involved in anaerobic carbon fixation, aerobic carbon fixation, fermentation, most nitrogen metabolism pathways, dissimilatory sulfate reduction, sulfide oxidation, polysulfide reduction, 2-phosphonopropionate transporter, and phosphate regulation. WMCs were enriched in genes involved in assimilatory sulfate reduction, sulfur mineralization, phosphonoacetate hydrolase, and phosphonate transport. Functional potentials suggest the differences of greenhouse gas emission, nutrient cycling, and living strategies between SMCs and WMCs. This study provides insight into the main biogeochemical processes and their properties in thermokarst lakes in YRSA, improving our understanding of the roles and fates of these lakes in a warming world.


Assuntos
Lagos , Metagenômica , Lagos/microbiologia , Água , Rios , Nitrogênio , Sulfatos
5.
J Environ Manage ; 330: 117105, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36610191

RESUMO

Near-ground ozone in the Yangtze River Delta (YRD) region has become one of the main air pollutants that threaten the health of residents. However, to date, the transport behavior and source areas of ozone in the YRD region have not been systematically analyzed. In this study, by combining the ozone observational record with a HYSPLIT (hybrid single-particle Lagrangian integrated trajectory) model, we tried to reveal the spatiotemporal regularity of the airflow transport trajectory of ozone. Spatially, high ozone concentrations mainly clustered in industrial cities and resource-based cities. Temporally, the center of the ozone pollution shifted westward of Nanjing from 2015 to 2021. With the passage of time, the influence of meteorological elements on the ozone concentration in the YRD region gradually weakened. Marine atmosphere had the most significant impact on the transmission path of ozone in Shanghai, of which the trajectory frequency in 2021 accounted for 64.21% of the total frequency. The transmission trajectory of ozone in summer was different from that in other seasons, and its transmission trajectory was mainly composed of four medium-distance transmission paths: North China-Bohai Sea, East China Sea-West Pacific Ocean, Philippine Sea, and South China Sea-South China. The contribution source areas mainly shifted to the southeast, and the emission of pollutants from the Shandong Peninsula, the Korean Peninsula-Japan, and the Philippine Sea-Taiwan area increased the impact of ozone pollution in the Shanghai area from 2019 to 2021. This study identified the regional transport path of ozone in the YRD region and provided a scientific reference for the joint prevention and control of ozone pollution in this area.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Ozônio , China , Monitoramento Ambiental , Poluentes Atmosféricos/análise , Estações do Ano , Material Particulado/análise
6.
Molecules ; 28(17)2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37687073

RESUMO

Vinyl acetate is a restricted substance in food products. The quantification of the organic impurities in vinyl acetate is a major problem due to its activity, instability, and volatility. In this paper, while using the mass balance method to determine the purity of vinyl acetate, an improved method was established for the determination of the content of three impurities in vinyl acetate reference material, and the GC-FID peak area normalization for vinyl acetate was calibrated. The three trace organic impurities were identified by gas chromatography tandem high-resolution mass spectrometry to be methyl acetate, ethyl acetate, and vinyl propionate. The content and relative correction factors for the three organic impurities were measured. The purity of vinyl acetate determined by the mass balance method was 99.90% with an expanded uncertainty of 0.30%, and the total content of organic impurities was 0.08% with a relative correction factor of 1.23%. The vinyl acetate reference material has been approved as a national certified reference material in China as GBW (E) 062710.

7.
J Am Chem Soc ; 144(19): 8789-8796, 2022 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-35503747

RESUMO

Desilylative coupling involving C-Si bond cleavage has emerged as one of the most important synthetic strategies for carbon-carbon/heteroatom bond formation in solution chemistry. However, in on-surface chemistry, C-Si bond cleavage remains a synthetic challenge. Here, we report the implementation of C(sp2)-Si bond cleavage and subsequent C-C bond formation on metal surfaces. The combination of scanning tunneling microscopy and density functional theory calculation successfully reveals that the incorporation of the C-Br group on the arylsilanes is critical to the success of this desilylative coupling reaction on metal surfaces. Our study represents a promising approach for the removal of protecting silyl groups in on-surface chemistry.


Assuntos
Carbono , Microscopia de Tunelamento , Carbono/química , Metais
8.
Anal Chem ; 94(11): 4686-4694, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35271257

RESUMO

Insertions/deletions (indels) variations have been recognized as a promising marker for the development of various diseases. However, methods used for the genotyping of indels in studies were tedious, complicated, and required sophisticated or expensive instruments, as well as complex data analysis, which makes it difficult to meet the demand of point of care testing. Herein, we presented a fast and accurate biosensor (T-ARMS-PCR-LFA) by the combination of tetra-primer amplification refractory mutation system polymerase chain reaction (T-ARMS-PCR) and GoldMag lateral flow assay (LFA) for visual genotyping of ACE I/D polymorphism. ACE I/D can be distinguished by employing four primers in one PCR reaction, and genotyping results were presented by the visual inspection of colors on the nitrocellulose membrane of LFA strips within 5 min. And 50 of the human genomic DNA samples were used for the detection of ACE I/D to further validate the accuracy of the T-ARMS-PCR-LFA system. As a demonstration, we showed that ACE I/D could be genotyped using a low amount of DNA sample (25 ng) with an accuracy of 100%, without complicated operation steps and data analysis, which is better than that of the conventional method (agarose gel electrophoresis analysis after common PCR). In conclusion, the biosensor is highly applicable for genotyping specific large indel variants in clinical practices, which enables rapid clinical decision-making, improves the management of disease diagnosis, and facilitates personalized medicine.


Assuntos
Técnicas de Genotipagem , Peptidil Dipeptidase A , Polimorfismo de Nucleotídeo Único , DNA/genética , Genótipo , Humanos , Mutação , Peptidil Dipeptidase A/genética , Reação em Cadeia da Polimerase/métodos
9.
Small ; 18(47): e2204271, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36228104

RESUMO

The surface properties of organic-inorganic hybrid perovskites can strongly affect the efficiency and stability of corresponding devices. Even though different surface passivation methods are developed, the microscopic structures of solution-processed perovskite film surfaces are not systematically studied. This study uses low-temperature scanning tunneling microscopy to study the organic-inorganic hybrid perovskite thin films, MA0.4 FA0.6 PbI3 and MAPbI3 , synthesized by the spin-coating method. Flat surface structures, atomic steps, and crystal grain boundaries are resolved at an atomic resolution. The surface imperfections are also characterized, as well as the dominant defects. Simulations on different types of iodine vacancy configurations are performed by density functional theory calculations. In addition, it is observed that the surface iodine lattice structure is unstable during scanning. Tip scanning can also cause the vertical migration of surface iodine ions. The measurements provide the direct visualizations of the surface imperfections of the solution-processed perovskite films. They are essential for understanding the surface-related optoelectronic effects and rationally designing more efficient surface passivation methods.

10.
Phys Chem Chem Phys ; 24(42): 25885-25894, 2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36259743

RESUMO

A neural network potential (NNP) is developed to investigate the complex reaction dynamics of 1,3,5-trinitro-1,3,5-triazine (RDX) thermal decomposition. Our NNP model is proven to possess good computational efficiency and retain the ab initio accuracy, which allows the investigation of the entire decomposition process of bulk RDX crystals from an atomic perspective. A series of molecular dynamics (MD) simulations are performed on the NNP to calculate the physical and chemical properties of the RDX crystal. The results show that the NNP can accurately describe the physical properties of RDX crystals, such as the cell parameters and the equation of state. The simulations of RDX thermal decomposition reveal that the NNP could capture the evolution of species at ab initio accuracy. The complex reaction network was established, and a reaction mechanism of RDX decomposition was provided. The N-N homolysis is the dominant channel, which cannot be observed in previous DFT studies of isolated RDX molecule. In addition, the H abstraction reaction by NO2 is found to be the critical pathway for NO and H2O formation, while the HONO elimination is relatively weak. The NNP gives an atomic insight into the complex reaction dynamics of RDX and can be extended to investigate the reaction mechanism of novel energetic materials.


Assuntos
Simulação de Dinâmica Molecular , Triazinas , Triazinas/química , Redes Neurais de Computação
11.
Molecules ; 27(21)2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36364109

RESUMO

The purpose of the present study aims to develop a satisfactory model for predicting pro-social and pro-cognitive effects on azinesulfonamides of cyclic amine derivatives as potential antipsychotics. The three dimensional-quantitative structure affinity relationship (3D-QSAR) study was performed on a series of azinesulfonamides of cyclic amine derivative using comparative molecular similarity indices analysis (CoMSIA). The best statistical model of CoMSIA q2, r2, SEE and F values are 0.664, 0.973, 0.087, and 82.344, respectively. Based on the model contour maps and the highest activity structure of the 43rd compound, serial new structures were designed and the 43k1 compound was selected as the best structure. The dock results showed a good binding of 43k1 with the protein (PDB ID: 6A93). The QSAR model analysis of the contour maps can help us to provide guidelines for finding novel potential antipsychotics.


Assuntos
Antipsicóticos , Transtorno Autístico , Humanos , Simulação de Acoplamento Molecular , Relação Quantitativa Estrutura-Atividade , Chumbo , Antipsicóticos/farmacologia , Aminas
12.
Angew Chem Int Ed Engl ; 61(19): e202115489, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35076991

RESUMO

Lowly expressed analyte in complex cytoplasmic milieu necessitates the development of non-enzymatic autocatalytic DNA circuits with high amplification and anti-interference performance. Herein, we engineered a versatile and robust stimuli-responsive autocatalytic hybridization assembly (AHA) circuit for high-performance in vivo bioanalysis. Under a moderately confined condition, the initiator motivated the autonomous and cooperative cross-activation of cascade hybridization reaction and catalytic DNA assembly for generating an exponentially amplified readout without the parasite steric hindrance and random diffusion side effects. The AHA circuit was systematically investigated by a series of experimental studies and theoretical simulations. The successively guaranteed target recognition and synergistically accelerated signal-amplification enabled the sensitive and selective detection of analyte, and realized the robust miRNA imaging in living cells and mice. This autocatalytic DNA circuit could substantially expand the toolbox for accurate diagnosis and programmable therapeutics.


Assuntos
Técnicas Biossensoriais , DNA Catalítico , MicroRNAs , Animais , Técnicas Biossensoriais/métodos , DNA/genética , DNA Catalítico/metabolismo , Camundongos , MicroRNAs/análise , Técnicas de Amplificação de Ácido Nucleico/métodos , Hibridização de Ácido Nucleico
13.
Nutr Cancer ; 73(8): 1459-1470, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32762372

RESUMO

Cervical cancer (CC) is a common gynecological malignancy and represents a major global health challenge. Chemotherapeutic agents are commonly applied in treatment of CC, while along various adverse effects and chemotherapy resistance. As an iridoid glycoside compound, gentiopicroside (GPS) possesses the characteristic of the better availability and lower toxicity effect on cancer treatment. In the present study, we investigated that GPS exhibited the anticancer effect on HeLa cells through the inhibition of cell growth, induced apoptosis, cycle arrest, and suppressed migration. Furthermore, the possible mechanism or the targets of GPS was also clarified. The results revealed that GPS exerted an anti-proliferation effect in a dose- and time-dependent manner in HeLa cells, in contrast, with the less inhibiting proliferation effects on normal cell line (HUVEC). Moreover, GPS arrested cells at G2/M phase and induced apoptosis through mitochondrial apoptotic pathway. More significantly, GPS dramatically inhibited the migration of HeLa cells and regulated the matrix metalloproteinase expression through the MAPK and Akt signaling pathways, of which MAPK1 was an underlying target in GPS against HeLa cells.


Assuntos
Glucosídeos Iridoides/farmacologia , Sistema de Sinalização das MAP Quinases , Proteínas Proto-Oncogênicas c-akt , Neoplasias do Colo do Útero , Apoptose , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Células HeLa , Humanos , Proteínas Proto-Oncogênicas c-akt/genética , Neoplasias do Colo do Útero/tratamento farmacológico
14.
Anticancer Drugs ; 32(9): 930-938, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34016833

RESUMO

Hesperetin is an abundant flavonoid in citrus fruits, and be confirmed to possess a chemo-preventive effect on cancer. Migration and invasion are the main causes of death of cervical cancer patients, in which epithelial-mesenchymal transition (EMT) can directly contribute to malignant phenotypes of tumor cells. The present study aims to investigate the inhibitory effect of hesperetin on EMT-mediated invasion and migration in cervical cancer cells through transforming growth factor-ß1 (TGF-ß1)/Smads pathway. Cell viability, cell migration and invasion ability, and cell morphology were evaluated and monitored using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assays, Transwell assays and optical microscope, respectively. The change of EMT marker protein E-cadherin and N-cadherin was assessed by immunofluorescence assay, whereas the protein expression of EMT bio-marker and TGF-ß1/Smads pathway were detected through western blot analysis. In conclusion, hesperetin can suppress EMT-mediated invasion and migration of cervical cancer cells by inhibiting abnormal activation of TGF-ß1/Smads pathway. The study provides an experimental basis for the prevention of the invasion and migration of cervical cancer.


Assuntos
Transição Epitelial-Mesenquimal/efeitos dos fármacos , Hesperidina/farmacologia , Proteínas Smad/efeitos dos fármacos , Fator de Crescimento Transformador beta1/efeitos dos fármacos , Neoplasias do Colo do Útero/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células/efeitos dos fármacos , Feminino , Células HeLa , Humanos , Transdução de Sinais/efeitos dos fármacos
15.
Analyst ; 146(12): 4080-4086, 2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34052846

RESUMO

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) has been widely applied for the analysis of large biomolecules. The emergence of inorganic material substrates and new organic matrices extends the use of MALDI MS for small molecule analyses. However, there are usually preferred matrices for different types of analytes. Here, an organic compound, 4-hydroxy-3-nitrobenzonitrile, was found to be a general purpose matrix for the analyses of small organic, peptide and protein molecules. In particular, 4-hydroxy-3-nitrobenzonitrile has a strong UV absorption property, and it provides a clean background in the low mass range. Its analytical performances as a UV-laser matrix were demonstrated for different types of analytes, including organic drugs, peptides, proteins, mouse brain tissue and bacteria. Compared with commercial matrices, this new matrix has better performances when analyzing small molecules, such as drugs, peptides and lipids, while it has similar performances when analyzing proteins.


Assuntos
Peptídeos , Proteínas , Animais , Lipídeos , Camundongos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
16.
Analyst ; 146(7): 2248-2254, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33599220

RESUMO

Tumorigenesis driven by abnormal DNA methylation has highlighted the need to develop a portable, rapid and sensitive strategy for accurate methylation detection with a specific cancer-prognostic gene, which caters to the popularization of precision medicine. In this study, a site-specific biosensor for both visual and magnetic DNA methylation determination has been established based on lateral flow assay. By introducing digoxin- and biotin-labeled primers into PCR, the amplicons can be recognized and captured by gold magnetic nanoparticles (GMNPs) in this biosensor. Working as a signal probe, the optical property of GMNPs allows the amplicons to be interpreted with naked eyes avoiding any complex equipment and cumbersome operation after PCR. Moreover, by virtue of the magnetic property of GMNP, the signal can be explained and recorded by a magnetometer in clinical practice. The introduction of tailor-made primer sets makes it possible to accurately distinguish 0.1% methylated variants in the presence of numerous unmethylated variants as strong interferential background and vice versa at target cytosine-guanine dinucleotide. A distinct signal can be observed with as low as 0.01 pg variants for both visual and magnetic analyses. As a significant tumor suppressor gene, the promoter methylation status of miR-34a is accurately determined with not only cell lines but also with clinical samples, which demonstrates the great potential of this biosensor for cancer diagnosis and prognosis.


Assuntos
Técnicas Biossensoriais , Metilação de DNA , Ouro , Fenômenos Magnéticos , Reação em Cadeia da Polimerase
17.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 50(1): 106-112, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-34117854

RESUMO

:To investigate the effect of transient receptor potential melastatin 2 (TRPM2) inhibitor A10 on oxygen glucose deprivation/reperfusion (OGD/R) injury in SH-SY5Y cells.:Human neuroblastoma SH-SY5Y cells were subject to OGD/R injury,and then were divided into blank control group,model control group and A10 group randomly. The cell survival rate was detected by cell counting kit 8 (CCK-8); the level of cellular reactive oxygen species (ROS) was detected by reactive oxygen detection kit; the mitochondrial membrane potential was detected by tetramethylrhodamine (TMRM) method; the number of apoptotic cells was detected by TUNEL apoptosis assay kit; the protein expression level of cleaved caspase 3 was detected by Western blot.:Compared with 3,20,30,50, has lower cytotoxicity and better inhibition effect on channel activity. Compared with the model control group,ROS level was reduced,the mitochondrial membrane potential was improved,the number of apoptosis cells was reduced ,and the expression of cleaved caspase 3 was significantly reduced in the A10 group(all <0.05). : A10 can alleviate cell damage after OGD/R by inhibiting TRPM2 channel function,reducing extracellular calcium influx,reducing cell ROS levels,stabilizing mitochondrial membrane potential levels,and reducing apoptosis.


Assuntos
Glucose , Canais de Cátion TRPM , Apoptose , Benzenoacetamidas , Sobrevivência Celular , Humanos , Oxigênio/metabolismo , Piperidonas , Espécies Reativas de Oxigênio/metabolismo , Reperfusão
18.
Educ Inf Technol (Dordr) ; 26(6): 6675-6697, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33723481

RESUMO

Online teaching transition during COVID-19 school lockdown elicited challenges for teachers and schools across the globe. The existing literature on the impact of COVID-19 in the education sector is predominantly descriptive and focused on the difficulties faced by teachers during the process of transferring into online teaching, mainly in the higher education sector. This study adopted a mixed-method design to examine online teaching self-efficacy (TSE) during COVID-19, its associated factors and moderators. A sample of 351 Chinese school teachers retrospectively reported their online TSE at the beginning and end of COVID-19 school lockdown, out of which six were followed up for an in-depth interview. TSE for online instruction did not significantly increase (ß = .014, p > 0.05) whereas that for technology application increased significantly (ß = .231, p < 0.01). Lack of experience in online teaching, separation of teachers from students, school administrative process and unsatisfactory student academic performance were identified as the major associated factors. A moderation effect of adaptability and teacher burnout on the change in online TSE were examined, of which passion burnout was the only significant moderator toward the change in online TSE. The study thus concluded that teachers' online TSE for technology application increased among Chinese teachers during COVID-19 school lockdown. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10639-021-10486-3.

19.
J Cell Physiol ; 235(3): 2171-2182, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31468534

RESUMO

Curcumin (CUR) shows a remarkable antitumor activity against a wide range of cancers such as glioma, but its underlying mechanism remains elusive. In this study, we aimed to explore the potential role of H19/miR-675/vitamin D receptor (VDR) in the effect of CUR against glioma. Real-time polymerase chain reaction and western-blot analysis were used to study the effect of CUR or 1,25-dihydroxyvitamin D (1,25(OH)2 D3 ) on the expression of H19, miR-675, and VDR. In addition, the effect of H19 on VDR expression was also studied. Furthermore, the expression of H19, miR-675, and VDR between CUR-loaded nanoparticles (NPs) and NP groups was compared, and the interaction among H19, miR-675, and VDR was analyzed by in-silicon and luciferase assays. In a dose-dependent manner, CUR and 1,25(OH)2 D3 both downregulated the expression of H19 and miR-675 but increased the expression of VDR. In addition, H19 evidently reduced the mRNA and protein levels of VDR. Furthermore, VDR was confirmed as a target gene of miR-675, which significantly reduced the expression of VDR. Finally, the administration of CUR evidently decreased tumor volume. CUR-loaded NP group exhibited lower levels of H19 and miR-675, while the NP group showed higher levels of VDR mRNA and protein. In summary, it is the first time that the involvement of a negative feedback loop of H19/miR-675/VDR has been demonstrated in the development of glioma. Therefore, H19 might serve as a new biomarker for the diagnosis and treatment of glioma.


Assuntos
Curcumina/farmacologia , Glioma/tratamento farmacológico , Glioma/genética , MicroRNAs/genética , RNA Longo não Codificante/genética , Receptores de Calcitriol/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Retroalimentação , Feminino , Humanos , RNA Mensageiro/genética , Ratos , Ratos Wistar
20.
Small ; 16(41): e2002348, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32939990

RESUMO

Nanozyme has emerged as a versatile nanocatalyst yet is constrained with limited catalytic efficiency and specificity for various biomedical applications. Herein, by elaborately integrating the recognition/transduction carbon dots (CDs) with platinum nanoparticles (PtNPs), an exquisite CDs@PtNPs (CPP) nanoflare is engineered as an efficient and substrate-specific peroxidase-mimicking nanozyme for high-performance biosensing and antibacterial applications. The intelligent CPP-catalyzed hydrogen peroxide (H2 O2 )-generated reactive oxygen species realize the sensitive diagnosis-guided enhanced disinfection of pathogens. Significantly, the CPP nanozyme shows the prominent biofilm eradication and wound healing in vivo by virtue of endogenous H2 O2 in acidic infection tissues, which can substantially preclude the annoying antibiotics resistance. A fundamental understanding on the present CPP nanoflare would not only facilitate the advancement of various prospective biocatalysts, but also establish a multifunctional means for versatile biosensing and smart diagnostic applications.


Assuntos
Nanopartículas Metálicas , Platina , Biofilmes , Catálise , Estudos Prospectivos
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