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1.
Proc Natl Acad Sci U S A ; 120(52): e2310916120, 2023 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-38117856

RESUMEN

The kinetics and pathway of most catalyzed reactions depend on the existence of interface, which makes the precise construction of highly active single-atom sites at the reaction interface a desirable goal. Herein, we propose a thermal printing strategy that not only arranges metal atoms at the silica and carbon layer interface but also stabilizes them by strong coordination. Just like the typesetting of Chinese characters on paper, this method relies on the controlled migration of movable nanoparticles between two contact substrates and the simultaneous emission of atoms from the nanoparticle surface at high temperatures. Observed by in situ transmission electron microscopy, a single Fe3O4 nanoparticle migrates from the core of a SiO2 sphere to the surface like a droplet at high temperatures, moves along the interface of SiO2 and the coated carbon layer, and releases metal atoms until it disappears completely. These detached atoms are then in situ trapped by nitrogen and sulfur defects in the carbon layer to generate Fe single-atom sites, exhibiting excellent activity for oxygen reduction reaction. Also, sites' densities can be regulated by controlling the size of Fe3O4 nanoparticle between the two surfaces. More importantly, this strategy is applicable to synthesize Mn, Co, Pt, Pd, Au single-atom sites, which provide a general route to arrange single-atom sites at the interface of different supports for various applications.

2.
Crit Rev Immunol ; 44(6): 75-85, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38848295

RESUMEN

Laryngeal cancer (LC) is a prevailing tumor with a high mortality rate. The pivotal role of mitophagy in LC is acknowledged; however, a comprehensive analysis of the corresponding genes has not been conducted. In the present study, we proposed a prognostic model consisting of mitophagy-related genes in LC. Clinical information and transcriptome profiling of patients with LC and mitophagy-related genes were retrieved from open-source databases. Gene set variation analysis (GSVA) and Weighted Gene Co-expression Network Analysis (WGCNA) were used to identify core mitophagy-related genes and construct gene co-expression networks. Functional enrichment analysis was employed to analyze the enriched regulatory pathways of the mitophagy-related genes. Kaplan-Meier curves (KM), Cox, and LASSO regression were applied to explore their prognostic effects. Finally, quantitative real-time PCR (RT-qPCR) further verified the bioinformatics prediction. A total of 45 genes related to mitochondrial pathways was collected. GSVA analysis demonstrated that these genes in tumor samples mainly referred to the mitochondrial pathway. Among these genes, five mitophagy-related-gene signatures (CERCAM, CHPF, EPHX3, EXT2, and MED15) were further identified to construct the prognostic model. KM and Cox regression analyses indicated that this model had an accurate prognostic prediction for LC. RT-qPCR showed that CERCAM, CHPF, EXT2, and MED15 expression were upregulated, and EPHX3 level was decreased in LC cells. The present study established a five-mitophagy-related-gene model that can predict the prognosis of LC patients, thus laying the foundation for a better understanding and potential advancements in clinical treatments for LC.


Asunto(s)
Biomarcadores de Tumor , Biología Computacional , Regulación Neoplásica de la Expresión Génica , Neoplasias Laríngeas , Mitofagia , Humanos , Mitofagia/genética , Neoplasias Laríngeas/genética , Neoplasias Laríngeas/diagnóstico , Neoplasias Laríngeas/mortalidad , Biología Computacional/métodos , Pronóstico , Biomarcadores de Tumor/genética , Perfilación de la Expresión Génica , Redes Reguladoras de Genes , Transcriptoma
3.
Angew Chem Int Ed Engl ; 63(29): e202404568, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38696242

RESUMEN

Few-atom metal clusters (FAMCs) exhibit superior performance in catalyzing complex molecular transformations due to their special spatial environments and electronic states, compared to single-atom catalysts (SACs). However, achieving the efficient and accurate synthesis of FAMCs while avoiding the formation of other species, such as nanoparticles and SACs, still remains challenges. Herein, we report a two-step strategy for synthesis of few-atom platinum (Pt) clusters by predeposition of zinc single-atom-glue (Zn1) on MgO nanosheets (Ptn-Zn1/MgO), where FAMCs can be obtained over a wide range of Pt contents (0.09 to 1.45 wt %). Zn atoms can act as Lewis acidic sites to allow electron transfer between Zn and Pt through bridging O atoms, which play a crucial role in the formation and stabilization of few-atom Pt clusters. Ptn-Zn1/MgO exhibited a high selectivity of 93 % for anti-Markovnikov alkene hydrosilylation. Moreover, an excellent activity with a turnover frequency of up to 1.6×104 h-1 can be achieved, exceeding most of the reported Pt SACs. Further theoretical studies revealed that the Pt atoms in Ptn-Zn1/MgO possess moderate steric hindrance, which enables high selectivity and activity for hydrosilylation. This work presents some guidelines for utilizing atomic-scale species to increase the synthesis efficiency and precision of FAMCs.

4.
Infect Immun ; 91(5): e0002923, 2023 05 16.
Artículo en Inglés | MEDLINE | ID: mdl-37039643

RESUMEN

Cystic echinococcosis (CE) is a common zoonotic parasitic disease that seriously impacts public health. However, the full spectrum of immune cell changes in Echinococcus granulosus infection, especially the negative immune regulation of subpopulations of regulatory T (Treg) cells, are not yet well understood. In this study, we used single-cell RNA sequencing and immunome repertoire (IR) sequencing to analyze 53,298 cells from the spleens and peripheral blood mononuclear cells (PBMCs) of healthy and E. granulosus-infected mice. We used immunofluorescence combined with RNA fluorescence in situ hybridization and quantitative real-time PCR to verify the sequencing results. Our results showed tissue-specific immune system alterations in mice infected with E. granulosus. E. granulosus-infected mice induced a subpopulation of CD4+ cells with type I interferon production potential. Furthermore, there were six different Treg cell subpopulations in vivo at three stages of differentiation, and Treg subpopulations of different classes and different stages of differentiation showed tissue specificity. After infection, the Lag3hi Treg and Gpr83+Igfbp4+ naive Treg subpopulations were specifically induced in PBMCs and the spleen, respectively. Furthermore, T follicular helper 2 (Tfh2) cells with high expression of Cxxc5 and Spock2 were found in E. granulosus-infected mice. Our data uncovered changes in the full spectrum of immune cells in mice following the late stages of E. granulosus infection, including subpopulations of cells that have not been emphasized in previous studies. These results further enrich the study of the bidirectional immunomodulatory mechanism and offer a different perspective for subsequent studies of infection in E. granulosus.


Asunto(s)
Equinococosis , Echinococcus granulosus , Animales , Ratones , Echinococcus granulosus/genética , Linfocitos T Reguladores , Hibridación Fluorescente in Situ , Leucocitos Mononucleares , Zoonosis , Análisis de Secuencia de ARN , Receptores Acoplados a Proteínas G , Proteínas de Unión al ADN , Factores de Transcripción
5.
J Am Chem Soc ; 145(24): 13462-13468, 2023 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-37293805

RESUMEN

Arranging atoms in an orderly manner at the atomic scale to create stable polyatomic structures is a very challenging task. In this study, we have developed three-dimensional confinement areas on the two-dimensional surface by creating regional defects. These areas are composed of vertically stacked graphene layers, where Ni and Fe atoms are anchored concentrically to form axial dual atomic sites in high yield. These sites can be used to produce tunable syngas through the electroreduction of CO2. Theoretical calculations indicate that the Ni sites vertically regulate the charge distribution of the adjacent Fe sites in the layer below, resulting in a lower d-band center. This, in turn, weakens the adsorption of the *CO intermediate and inhibits the production of H2 at the Fe site. Our research presents a novel approach for concentrated creation of dual atomic sites by building a confinement-selective surface.

6.
Small ; 19(45): e2302328, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37431211

RESUMEN

The design of an efficient catalytic system with low Pt loading and excellent stability for the acidic oxygen reduction reaction is still a challenge for the extensive application of proton-exchange membrane fuel cells. Here, a gas-phase ordered alloying strategy is proposed to construct an effective synergistic catalytic system that blends PtM intermetallic compounds (PtM IMC, M = Fe, Cu, and Ni) and dense isolated transition metal sites (M-N4 ) on nitrogen-doped carbon (NC). This strategy enables Pt nanoparticles and defects on the NC support to timely trap flowing metal salt without partial aggregation, which is attributed to the good diffusivity of gaseous transition metal salts with low boiling points. In particular, the resulting Pt1 Fe1 IMC cooperating with Fe-N4 sites achieves cooperative oxygen reduction with a half-wave potential up to 0.94 V and leads to a high mass activity of 0.51 A  mgPt -1 and only 23.5% decay after 30 k cycles, both of which exceed DOE 2025 targets. This strategy provides a method for reducing Pt loading in fuel cells by integrating Pt-based intermetallics and single transition metal sites to produce an efficient synergistic catalytic system.

7.
Inorg Chem ; 62(46): 19123-19134, 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-37945002

RESUMEN

Electrochemical hydrogeneration (ECH) of biomass-derived platform molecules, which avoids the disadvantages in utilizing fossil fuel and gaseous hydrogen, is a promising route toward value-added chemicals production. Herein, we reported a CoO/Co heterostructure-supported Pt single atoms electrocatalyst (Pt1-CoO/Co) that exhibited an outstanding performance with a high conversion (>99%), a high Faradaic efficiency (87.6%), and robust stability (24 recyclability) at -20 mA/cm2 for electrochemical phenol hydrogenation to high-valued KA oil (a mixture of cyclohexanol and cyclohexanone). Experimental results and the density functional theory calculations demonstrated that Pt1-CoO/Co presented strong adsorption of phenol and hydrogen on the catalyst surface simultaneously, which was conducive to the transfer of the adsorbed hydrogen generated on the single atom Pt sites to activated phenol, and then, ECH of phenol with high performance was achieved instead of the direct hydrogen evolution reaction. This work described that the multicomponent synergistic single atom catalysts could effectively accelerate the ECH of phenol, which could help the achievement of large-scale biomass upgrading.

8.
J Environ Manage ; 348: 119408, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37879180

RESUMEN

Sulfamethoxazole (SMX) has been widely detected in various environments and its potential environmental risks have caused great concerns. However, the impact mechanism of SMX on microbial interactions among anammox consortia remain unknown. A long-term exposure experiments (140 d) was carried out to systematically examine the influence of SMX (0-1000 µg/L) on the anammox system, especially microbial network dynamics and variations of key metabolic genes. Results showed that anammox system could adapt to SMX below 500 µg/L and maintain a high nitrogen removal efficiency (NRE) of 85.35 ± 2.42%, while 1000 µg/L SMX significantly decreased the abundance of functional microbes and deteriorated denitrification performance with NRE dropped to 36.92 ± 15.01%. Co-occurrence network analysis indicated that 1000 µg/L SMX decreased the interactions between Proteobacteria and Chloroflexi and limited AnAOB from playing an important role as central nodes in the subnetwork of Planctomycetes. Metagenomics analysis found that genes associated with nitrogen removal (i.e., hdh, hzs, nirS, and hao) showed lower expression level after addition of SMX, while SMX-related ARGs (sul1 and sul2) increased by 1.22 and 2.68 times. This study provided us a relatively comprehensive perspective in response of microbial interactions and metabolic activity to various SMX concentrations.


Asunto(s)
Oxidación Anaeróbica del Amoníaco , Sulfametoxazol , Sulfametoxazol/farmacología , Nitrógeno , Interacciones Microbianas
9.
Angew Chem Int Ed Engl ; 62(12): e202300879, 2023 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-36721306

RESUMEN

Charge redistribution on surface of Ru nanoparticle can significantly affect electrocatalytic HER activity. Herein, a double atomic-tuned RuBi SAA/Bi@OG nanostructure that features RuBi single-atom alloy nanoparticle supported by Bi-O single-site-doped graphene was successfully developed by one-step pyrolysis method. The alloyed Bi single atom and adjacent Bi-O single site in RuBi SAA/Bi@OG can synergistically manipulate electron transfer on Ru surface leading to optimum charge redistribution. Thus, the resulting RuBi SAA/Bi@OG exhibits superior alkaline HER activity. Its mass activity is up to 65000 mA mg-1 at an overpotential of 150 mV, which is 72.2 times as much as that of commercial Pt/C. DFT calculations reveal that the RuBi SAA/Bi@OG possesses the optimum charge redistribution, which is most beneficial to strengthen adsorption of water and weaken hydrogen-adsorption free energy in HER process. This double atomic-tuned strategy on surface charge redistribution of Ru nanoparticle opens a new way to develop highly efficient electrocatalysts.

10.
J Am Chem Soc ; 144(35): 15999-16005, 2022 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-35998643

RESUMEN

The orderly assembly of single atoms into highly periodic aggregates at the nanoscale is an intriguing but challenging process of high-precision atomic manufacturing. Here, we discover that an in-plane film surface shrinkage can induce molecular self-assembly to arrange single atoms with unconventional distribution, contributing them to periodic one-dimensional segregation on carbon stripes (one-dimensional single-atom arrays (SAA)). This originates from the fact that metal phthalocyanine (MPc) molecules gradually aggregate and melt to form a film under a thermal drive and the help of sodium chloride templates, accompanied by surface shrinkage, self-assembly, and deep carbonization. At the nanoscale, these periodic parallel arrays are formed due to MPc molecular interactions by π-π stacking. At the atomic scale, the single atoms are stabilized by the vertical phthalocyanine-derived multilayer graphene. This can significantly modify the electronic structure of the single-atom sites on the outermost graphene (e.g., Fe-based SAA), thus optimizing the adsorption energy of oxygen intermediates and resulting in a superior oxygen reduction reaction (ORR) performance concerning disordered single atoms. Our findings provide a general route for orderly single-atom manufacturing (e.g., Fe, Co, and Cu) and an understanding of the relationship between orderly allocation and catalytic performance.

11.
Neurourol Urodyn ; 41(3): 756-764, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35132690

RESUMEN

BACKGROUND: To study the influences of posterior tibial nerve stimulation (PTNS) on neurogenic bladder and the expression of transient receptor potential (TRP) channels and P2X receptors in rats with spinal cord injury (SCI) and explore the possible mechanism. METHODS: SCI model was established by modified Allen's method and PTNS was performed. Urodynamic indexes and Haematoxylin and Eosine staining of bladder tissue were used to evaluate the therapeutic effect. The expression of TRP channels and P2X receptors in the bladder and dorsal root ganglia (DRG) was detected by real-time PCR and Western blot. RESULTS: The low compliance of bladder in treatment group was significantly improved compared with SCI group, and the infiltration of inflammatory cells in bladder tissue was significantly reduced. At the same time, the expression of TRP and P2X in bladder and DRG was partially restored after the treatment of PTNS. CONCLUSIONS: PTNS is an effective therapy for SCI-induced neurogenic bladder via the TRP/P2X signaling pathway.


Asunto(s)
Traumatismos de la Médula Espinal , Canales de Potencial de Receptor Transitorio , Vejiga Urinaria Neurogénica , Animales , Femenino , Humanos , Masculino , Ratas , Transducción de Señal , Médula Espinal/metabolismo , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/metabolismo , Traumatismos de la Médula Espinal/terapia , Nervio Tibial , Canales de Potencial de Receptor Transitorio/metabolismo , Vejiga Urinaria/metabolismo , Vejiga Urinaria Neurogénica/etiología , Vejiga Urinaria Neurogénica/terapia
12.
Neurosurg Rev ; 45(2): 1521-1531, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34657975

RESUMEN

Intracranial aneurysms (IAs) remain a major public health concern and endovascular treatment (EVT) has become a major tool for managing IAs. However, the recurrence rate of IAs after EVT is relatively high, which may lead to the risk for aneurysm re-rupture and re-bleed. Thus, we aimed to develop and assess prediction models based on machine learning (ML) algorithms to predict recurrence risk among patients with IAs after EVT in 6 months. Patient population included patients with IAs after EVT between January 2016 and August 2019 in Hunan Provincial People's Hospital, and an adaptive synthetic (ADASYN) sampling approach was applied for the entire imbalanced dataset. We developed five ML models and assessed the models. In addition, we used SHapley Additive exPlanations (SHAP) and local interpretable model-agnostic explanation (LIME) algorithms to determine the importance of the selected features and interpret the ML models. A total of 425 IAs were enrolled into this study, and 66 (15.5%) of which recurred in 6 months. Among the five ML models, gradient boosting decision tree (GBDT) model performed best. The area under curve (AUC) of the GBDT model on the testing set was 0.842 (sensitivity: 81.2%; specificity: 70.4%). Our study firstly demonstrated that ML-based models can serve as a reliable tool for predicting recurrence risk in patients with IAs after EVT in 6 months, and the GBDT model showed the optimal prediction performance.


Asunto(s)
Aneurisma Roto , Aneurisma Intracraneal , Algoritmos , Aneurisma Roto/epidemiología , Aneurisma Roto/cirugía , Área Bajo la Curva , Humanos , Aneurisma Intracraneal/cirugía , Aprendizaje Automático
13.
Angew Chem Int Ed Engl ; 61(47): e202212329, 2022 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-36098059

RESUMEN

Single atom catalysts (SACs) have been widely studied in the field of CO2 electroreduction, but industrial-level current density and near-unity product selectivity are still difficult to achieve. Herein, a diatomic site catalysts (DASCs) consisting of Co-Cu hetero-diatomic pairs is synthesized. The CoCu DASC exhibits excellent selectivity with the maximum CO Faradaic efficiency of 99.1 %. The CO selectivity can maintain above 95 % over a wide current density range from 100 mA cm-2 to 500 mA cm-2 . The maximum CO partial current density can reach to 483 mA cm-2 in flow cell, far exceed industrial-level current density requirements (>200 mA cm-2 ). Theoretical calculation reveals that the synergistic catalysis of the Co-Cu bimetallic sites reduce the activation energy and promote the formation of intermediate *COOH. This work shows that the introduction of another metal atom into SACs can significantly affect the electronic structure and then enhance the catalytic activity of SACs.

14.
J Gene Med ; 23(6): e3325, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33619796

RESUMEN

BACKGROUND: Non-small cell lung cancer (NSCLC) is one of the most fatal malignant tumors. Emerging studies have clarified the crucial roles of circular RNAs (circRNAs) in the tumorigenesis of cancers. CircVAPA was demonstrated to function in some human cancers. The present study aimed to investigate the role of circVAPA in NSCLC. METHODS: A quantitative real-time polymerase chain reaction was used to measure the expression of genes. Actinomycin D and RNase R were employed to examine the stability of circVAPA. Cell-counting kit-8, 5-ethynyl-2'-deoxyuridine, Transwell and sphere formation assays, and well as western blot analysis, were conducted to examine the changes of NSCLC cells in response to circVAPA knockdown. A luciferase reporter assay was conducted for the molecular mechanism. RESULTS: Our findings demonstrated high expression of circVAPA in tissues and cell lines of NSCLC. Knockdown of circVAPA had a suppressive effect on cell proliferation, migration, invasion and stemness, and also inhibited tumor growth in vivo. Mechanistically, circVAPA acted as a competing endogenous RNA to up-regulate WNT5A by sponging miR-876-5p. Moreover, circVAPA activated Wnt/ß-catenin signaling by up-regulation of WNT5A. Rescue assays showed that silencing of miR-876-5p or overexpression of WNT5A reversed the circVAPA knockdown-mediated inhibition on cellular processes in NSCLC. CONCLUSIONS: CircVAPA promotes aggressive phenotypes of NSCLC cells by the miR-876-5p/WNT5A axis activating Wnt/ß-catenin signaling.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/genética , Transformación Celular Neoplásica/genética , Neoplasias Pulmonares/genética , MicroARNs/genética , ARN Circular , Proteínas de Transporte Vesicular/genética , Proteína Wnt-5a/genética , Adulto , Apoptosis/genética , Biomarcadores de Tumor , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular , Transformación Celular Neoplásica/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Interferencia de ARN , Vía de Señalización Wnt , Proteína Wnt-5a/metabolismo
15.
Phys Chem Chem Phys ; 23(7): 4178-4186, 2021 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-33586741

RESUMEN

Designing atomically dispersed metal catalysts for the nitrogen reduction reaction (NRR) is an effective approach to achieve better energy conversion efficiencies. In this study, we designed a series of single molybdenum (Mo) atom-anchored porous two-dimensional Mo porphyrin (2D Mo-Pp) monolayers modified by B, C, O, P and S as efficient NRR catalysts to improve the catalytic performance. We introduced two key parameters, θ (pz orbital filling of heteroatoms) and φ (Bader charge of central Mo atoms). It shows that θ and φ play important roles in nitrogen absorption by analyzing the regression models. In particular, the theoretical results suggested that the 2D Mo-Pp monolayer modified by B has an ultralow limiting potential of 0.35 V and can suppress the hydrogen evolution reaction, making the 2D Mo-Pp monolayer modified by B a promising NRR electrocatalyst with high efficiency and selectivity. This work provides insights into the rational design of the elaborate structure of single-atom catalysts with tunable electrocatalytic activities.

16.
Exp Mol Pathol ; 112: 104356, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31837324

RESUMEN

Our study proposed to investigate the function of potassium voltage-gated channel sub-family Q member 1 opposite strand 1 (KCNQ1OT1) in cerebral ischemia-reperfusion (I/R) injury and the underlying mechanism. We constructed an oxygen-glucose-deprivation/reoxygenation (OGD/R) model using the primary cortical neurons to mimic the cerebral I/R injury in vitro. Small inference RNA (siRNA) was used to silencing KCNQ1OT1. Dual luciferase assay was conducted to verify the interaction between KCNQ1OT1 and miR-9 and interaction between miR-9 and MMP8. CCK8 assay and flow cytometry analysis were applied for determing the viability and apoptosis of neurons, accordingly. QPCR and Western blot were performed to determine the RNA and protein expression. Our outcomes revealed that the expression of KCNQ1OT1 in cultured neurons was notably enhanced after suffered to OGD/R. Knockdown of KCNQ1OT1 weakened OGD/R-induced injury in neurons. Moreover, depletion of KCNQ1OT1 lead to the up-regulation of miR-9 and down-regulation of MMP8. Dual luciferase target validation assays demonstrated that KCNQ1OT1 directly interact with miR-9 and MMP8 is a direct target of miR-9, suggesting that KCNQ1OT1/miR-9/MMP8 might constitute the competing endogenous RNA (ceRNA) mechanism. Knockdown of MMP8 or up-regulation of miR-9 also could weaken OGD/R-induced injury. Furthermore, cells co-transfected with si-KCNQ1OT1, miR-9 mimic and si-MMP8 could significantly abolish the injury on neurons caused by OGD/R. Taken together, our data manifested that KCNQ1OT1 possibly acts as a facilitator in cerebral I/R injury through modulating miR-9/MMP8 axis as a ceRNA.


Asunto(s)
MicroARNs/genética , Neuronas/metabolismo , ARN Largo no Codificante/genética , Daño por Reperfusión/genética , Animales , Apoptosis/genética , Citometría de Flujo , Glucosa/metabolismo , Humanos , Ratones , Neuronas/patología , Oxígeno/metabolismo , ARN Interferente Pequeño/genética , Daño por Reperfusión/patología , Transducción de Señal/efectos de los fármacos
17.
Phys Chem Chem Phys ; 22(4): 2457-2465, 2020 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-31939963

RESUMEN

Lattice strain, either tensile or compressive, can fine-tune the electronic structure of surfaces via altering the distances between surface atoms, thereby modifying the catalytic activity of catalysts. Numerous examples of strain engineering have been applied to various electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), but strain-optimized 2D carbon-based single-atom electrocatalysts for catalyzing the overall water splitting reaction have received little attention. Here, we applied the lattice strain of Co,N co-decorated graphyne (Co@N1-GY) to directly optimize its catalytic activity for the overall water splitting reaction based on first-principles calculations. Our calculations suggest that compressive strain and tensile strain lead to less stability of Co@N1-GY and the distances between C and Co atoms increase linearly with the strain changing from compressive to tensile, thus linearly upshifting the p-band center of C atoms and the d-band center of Co atoms. In addition, biaxial strain has more remarkable effects on these properties than uniaxial strain. From compressive to tensile strain, the chemisorption of electrochemically generated intermediates in both HER and OER becomes weaker and weaker. A tensile strain of 0.5% on Co@N1-GY gives an ideal HER performance, while the OER reaches the minimum overpotential of 0.33 V under the biaxial tensile strain of 3%.

18.
Exp Parasitol ; 215: 107917, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32446699

RESUMEN

Cystic echinococcosis (CE) is a worldwide hazardous zoonotic parasitosis caused by Echinococcus granulosus. CE development involves complex immunological mechanisms, including participation of multiple immune cells and effector molecules. Myeloid-derived suppressor cells (MDSCs) are known to be involved in chronic and acute inflammatory conditions. In this study, we aimed to characterize the immune function of MDSCs in CE to improve the understanding, prevention and treatment of CE. Our results indicated that MDSCs overexpressing Ly6C and Ly6G inhibit the formation and activity of T helper 2 cells in a NO-dependent manner during E. granulosus infection.


Asunto(s)
Equinococosis/inmunología , Echinococcus granulosus/inmunología , Células Supresoras de Origen Mieloide/inmunología , Células Th2/inmunología , Análisis de Varianza , Animales , Anticuerpos Monoclonales , Arginasa/análisis , Médula Ósea/efectos de los fármacos , Médula Ósea/inmunología , Citocinas/análisis , Femenino , Citometría de Flujo , Humanos , Queratolíticos/farmacología , Ratones , Células Supresoras de Origen Mieloide/efectos de los fármacos , Células Supresoras de Origen Mieloide/enzimología , Óxido Nítrico/análisis , Especies Reactivas de Oxígeno/análisis , Organismos Libres de Patógenos Específicos , Bazo/citología , Bazo/efectos de los fármacos , Bazo/inmunología , Tretinoina/farmacología
19.
J Cell Mol Med ; 23(8): 5566-5575, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31187582

RESUMEN

SCL/TAL1 interrupting locus (STIL) regulates the mitotic centrosome to promote the centriolar replication and cell cycling, and is associated with malignancies. However, the role and mechanism of STIL in gastric cancer (GC) remain elusive. STIL expression in GC tissue microarray was detected by immunohistochemistry (IHC). GC cells were transduced with control lentivirus or lentivirus for expression STIL-specific shRNA and the effect of STIL silencing on the malignant behaviors of GC cells was measured in vitro and in vivo. The potential mechanisms underlying the action of STIL were analyzed by transcriptome microarray and bioinformatics. STIL expression was up-regulated in GC tissues both in our cohort and the data from the cancer genome atlas, and positively associated with T stage and poor overall survival of GC patients. Knockdown of STIL significantly inhibited the proliferation and clonogenicity of human GC cells and attenuated the growth of implanted GC in vivo. Furthermore, STIL silencing induced cell cycle arrest in G2/M phase and apoptosis of GC cells. Transcriptome analysis indicated that STIL silencing modulated many gene expression, particularly for down-regulating the IGF-1/PI3K/AKT pathway. In addition, treatment with SC79, an AKT activator, significantly mitigated the effect of STIL-silencing in GC cells. In conclusion, STIL promotes gastric carcinogenesis and progression by enhancing the IGF-1/PI3K/AKT signaling, and STIL may be a novel target for intervention of GC.


Asunto(s)
Progresión de la Enfermedad , Regulación hacia Abajo/genética , Técnicas de Silenciamiento del Gen , Factor I del Crecimiento Similar a la Insulina/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Neoplasias Gástricas/patología , Anciano , Animales , Apoptosis/genética , Puntos de Control del Ciclo Celular/genética , Proliferación Celular/genética , Células Clonales , Análisis por Conglomerados , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Masculino , Ratones Endogámicos BALB C , Ratones Desnudos , Persona de Mediana Edad , Transducción de Señal , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Regulación hacia Arriba/genética
20.
Nanotechnology ; 30(43): 435701, 2019 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-31300627

RESUMEN

It is essentially important to improve the performance of Zn-air batteries by studying bifunctional catalysts for oxygen evolution reactions (OER) and oxygen reduction reactions (ORR) with low-cost, high-efficiency and high-stability properties. Here, CoNi nanoparticles embedded in the bamboo-like N-doped carbon tubes (Co x Ni y @NC) were synthesized, where the optimized catalyst of Co2Ni1@NC exhibits superior bifunctional electrocatalytic activity, showing a low overpotential of 300 mV under the current density of 10 mA cm-2 for OER and a large limiting current density of 3.76 mA cm-2 under 0.40 V for ORR in an alkaline solution. In addition, the Co2Ni1@NC also shows excellent electrocatalytic activity in acidic and neutral solutions. Importantly, primary Zn-air batteries based on Co2Ni1@NC affords an excellent specific capacity of 834 mAh/gZn with a discharge potential of 1.25 V at 5 mA cm-2. A rechargeable Zn-air battery assembled with Co2Ni1@NC shows excellent cycling stability, where the first discharge and charge voltages reach 1.21 and 2.00 V under 1 mA cm-2, respectively. This finding provides a simple synthesis approach, which allows one to construct bifunctional catalysts based on metal@NC for future energy conversion and storage devices.

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