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1.
Cell Tissue Res ; 393(3): 471-487, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37458798

RESUMEN

Hyperlipidemia (HLP) is one of the risk factors for memory impairment and cognitive impairment. However, its pathological molecular mechanism remained unclear. 3ß-hydroxysterol Δ24- reductase (DHCR24) is a key enzyme in cholesterol synthesis and has been reported to decrease in the affected areas in the brain of neurodegenerative disorders. In this study, hyperlipidemic mouse model was established to study the effect of high blood lipid on brain. The data obtained from HPLC analysis demonstrated that the cholesterol level in the brain of mice with hyperlipidemia was significantly elevated compared to the control group. While the pathological damages were observed in both cerebral cortex and hippocampus in the brain of hyperlipidemic mice. Furthermore, the protein level of DHCR24 was downregulated accompanied by elevated ubiquitination level in the hyperlipidemic mice brain. The mouse neuroblastoma cells N2a were exposed to the excess cholesterol loading, the cells underwent apoptosis and the mRNA and protein of DHCR24 in cholesterol-loaded N2a cells were significantly reduced. In addition, the expression level of endoplasmic reticulum stress marker protein (Bip and Chop) was markedly increased in response to the cholesterol loading. More importantly, overexpression of DHCR24 in N2a reversed neuronal apoptosis induced by the cholesterol loading. Conclusively, these findings suggested that hyperlipidemia could cause brain tissue injuries via down-regulating DHCR24, and overexpression of DHCR24 may alleviate hyperlipidemia-induced neuronal cells damage by reversing the endoplasmic reticulum stress-mediated apoptosis.


Asunto(s)
Lesiones Encefálicas , Oxidorreductasas , Ratones , Animales , Oxidorreductasas/metabolismo , Oxidorreductasas/farmacología , Hidroxicolesteroles/farmacología , Estrés Oxidativo , Dieta Alta en Grasa , Apoptosis , Colesterol/metabolismo
2.
Molecules ; 28(6)2023 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-36985615

RESUMEN

Hyperlipidemia is a risk factor for the development of fatty liver and cardiovascular diseases such as atherosclerosis and coronary heart disease, and hence, cholesterol-lowering drugs are considered important and effective in preventing cardiovascular diseases. Thus, researchers in the field of new drug development are endeavoring to identify new types of cholesterol-lowering drugs. 3ß-hydroxysterol-Δ(24)-reductase (DHCR24) catalyzes the conversion of desmosterol to cholesterol, which is the last step in the cholesterol biosynthesis pathway. We speculated that blocking the catalytic activity of DHCR24 could be a novel therapeutic strategy for treating hyperlipidemia. In the present study, by virtually screening the DrugBank database and performing molecular dynamics simulation analysis, we selected four potential DHCR24 inhibitor candidates: irbesartan, risperidone, tolvaptan, and conivaptan. All four candidates showed significant cholesterol-lowering activity in HepG2 cells. The experimental mouse model of hyperlipidemia demonstrated that all four candidates improved high blood lipid levels and fat vacuolation in the livers of mice fed with a high-fat diet. In addition, Western blot analysis results suggested that irbesartan reduced cholesterol levels by downregulating the expression of the low-density lipoprotein receptor. Finally, the immune complex activity assay confirmed the inhibitory effect of irbesartan on the enzymatic activity of DHCR24 with its half-maximal inhibitory concentration (IC50) value of 602 nM. Thus, to the best of our knowledge, this is the first study to report that blocking the enzymatic activity of DHCR24 via competitive inhibition is a potential strategy for developing new cholesterol-lowering drugs against hyperlipidemia or multiple cancers. Furthermore, considering that irbesartan is currently used to treat hypertension combined with type 2 diabetes, we believe that irbesartan should be a suitable choice for patients with both hypertension and hyperlipidemia.


Asunto(s)
Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Hipertensión , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Animales , Ratones , Oxidorreductasas , Irbesartán , Desmosterol , Colesterol/metabolismo , Proteínas del Tejido Nervioso/metabolismo
3.
Molecules ; 28(21)2023 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-37959807

RESUMEN

Mycoplasma gallisepticum (MG) is recognized as a principal causative agent of avian chronic respiratory disease, inflicting substantial economic losses upon the poultry industry. However, the extensive use of conventional antibiotics has resulted in the emergence of drug resistance and various challenges in their clinical application. Consequently, there is an urgent need to identify effective therapeutic agents for the prevention and treatment of mycoplasma-induced respiratory disease in avian species. AMP-activated protein kinase (AMPK) holds significant importance as a regulator of cellular energy metabolism and possesses the capacity to exert an anti-inflammatory effect by virtue of its downstream protein, SIRT1. This pathway has shown promise in counteracting the inflammatory responses triggered by pathogenic infections, thus providing a novel target for studying infectious inflammation. Quercetin possesses anti-inflammatory activity and has garnered attention as a potential alternative to antibiotics. However, there exists a gap in knowledge concerning the impact of this activation on MG-induced inflammatory damage. To address this knowledge gap, we employed AlphaFold2 prediction, molecular docking, and kinetic simulation methods to perform a systematic analysis. As expected, we found that both quercetin and the AMPK activator AICAR activate the chicken AMPKγ1 subunit in a similar manner, which was further validated at the cellular level. Our project aims to unravel the underlying mechanisms of quercetin's action as an agonist of AMPK against the inflammatory damage induced by MG infection. Accordingly, we evaluated the effects of quercetin on the prevention and treatment of air sac injury, lung morphology, immunohistochemistry, AMPK/SIRT1/NF-κB pathway activity, and inflammatory factors in MG-infected chickens. The results confirmed that quercetin effectively inhibits the secretion of pro-inflammatory cytokines such as IL-1ß, TNF-α, and IL-6, leading to improved respiratory inflammation injury. Furthermore, quercetin was shown to enhance the levels of phosphorylated AMPK and SIRT1 while reducing the levels of phosphorylated P65 and pro-inflammatory factors. In conclusion, our study identifies the AMPK cascade signaling pathway as a novel cellular mediator responsible for quercetin's ability to counter MG-induced inflammatory damage. This finding highlights the potential significance of this pathway as an important target for anti-inflammatory drug research in the context of avian respiratory diseases.


Asunto(s)
Mycoplasma gallisepticum , FN-kappa B , Animales , FN-kappa B/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Quercetina/farmacología , Quercetina/uso terapéutico , Mycoplasma gallisepticum/metabolismo , Sirtuina 1/metabolismo , Simulación del Acoplamiento Molecular , Pollos/metabolismo , Inflamación/tratamiento farmacológico , Inflamación/prevención & control , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Antibacterianos/uso terapéutico
4.
Pharm Dev Technol ; 28(5): 414-424, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37067950

RESUMEN

To improve the aqueous solubility and oral bioavailability of paclitaxel (PTX), a biomimetic system for oral administration of PTX was efficiently developed as an outer membrane vesicle (OMVs) of sodium caseinate (CAS) modified zein nanoparticles (OMVs-Zein-CAS-PTX-NPs) by Escherichia coli. To verify their structure and properties, the designed nanostructures were thoroughly characterized using various characterization techniques. The results indicated that hydrogen bonds and van der Waals forces mainly drove the interaction between PTX and Zein, but the complex is unstable. The physicochemical stability of PTX-loaded zein nanoparticles was improved by the addition of CAS. The biological characteristics of biofilms are reproduced by nanoparticles cloaked with outer membrane vesicles. OMVs-Zein-CAS-PTX-NPs delayed the release of PTX under simulated gastric and intestinal fluids due to OMVs protection. OMVs-Zein-CAS-PTX-NPs exhibited remarkable antitumor ability in vitro and improved the bioavailability of oral administration of PTX in vivo. Therefore, OMVs cloaked in nanoparticles may be a suitable delivery vehicle to provide an efficient application prospect for the oral administration of PTX.


Asunto(s)
Nanopartículas , Zeína , Paclitaxel , Zeína/química , Portadores de Fármacos/química , Membrana Externa Bacteriana , Nanopartículas/química
5.
Plant Cell ; 30(2): 466-480, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29352065

RESUMEN

RNA polymerases IV and V (Pol IV and Pol V) are required for the generation of noncoding RNAs in RNA-directed DNA methylation (RdDM). Their subunit compositions resemble that of Pol II. The mechanism and accessory factors involved in their assembly remain largely unknown. In this study, we identified mutant alleles of MINIYO (IYO), QUATRE-QUART2 (QQT2), and NUCLEAR RNA POLYMERASE B11/D11/E11 (NRPB/D/E11) that cause defects in RdDM in Arabidopsis thaliana We found that Pol IV-dependent small interfering RNAs and Pol V-dependent transcripts were greatly reduced in the mutants. NRPE1, the largest subunit of Pol V, failed to associate with other Pol V subunits in the iyo and qqt2 mutants, suggesting the involvement of IYO and QQT2 in Pol V assembly. In addition, we found that IYO and QQT2 were mutually dependent for their association with the NRPE3 subassembly prior to the assembly of Pol V holoenzyme. Finally, we show that IYO and QQT2 are similarly required for the assembly of Pol II and Pol IV. Our findings reveal IYO and QQT2 as cofactors for the assembly of Pol II, Pol IV, and Pol V and provide mechanistic insights into how RNA polymerases are assembled in plants.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , ARN Polimerasas Dirigidas por ADN/metabolismo , GTP Fosfohidrolasas/metabolismo , Factores de Elongación Transcripcional/metabolismo , Alelos , Arabidopsis/enzimología , Arabidopsis/fisiología , Proteínas de Arabidopsis/genética , Metilación de ADN , ARN Polimerasas Dirigidas por ADN/genética , GTP Fosfohidrolasas/genética , Genes Reporteros , Mutación Puntual , ARN Polimerasa II/genética , ARN Polimerasa II/metabolismo , ARN Interferente Pequeño/genética , Factores de Elongación Transcripcional/genética
6.
Angew Chem Int Ed Engl ; 60(30): 16622-16627, 2021 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-34002464

RESUMEN

The catalytic activity of metal clusters is closely related with the support; however, knowledge on the influence of the support on the catalytic activity is scarce. We demonstrate that Pt nanoclusters (NCs) anchored on porous TiO2 nanosheets with rich oxygen vacancies (VO -rich Pt/TiO2 ) and deficient oxygen vacancies (VO -deficient Pt/TiO2 ), display significantly different catalytic activity for the hydrogen evolution reaction (HER), in which VO -rich Pt/TiO2 shows a mass activity of 45.28 A mgPt -1 at -0.1 V vs. RHE, which is 16.7 and 58.8 times higher than those of VO -deficient Pt/TiO2 and commercial Pt/C, respectively. DFT calculations and in situ Raman spectra suggest that porous TiO2 with rich oxygen vacancies can simultaneously achieve reversed charge transfer (electrons transfer from TiO2 to Pt NCs) and enhanced hydrogen spillover from Pt NCs to the TiO2 support, which leads to electron-rich Pt NCs being amenable to proton reduction of absorbed H*, as well as the acceleration of hydrogen desorption at Pt catalytic sites-both promoting the HER. Our work provides a new strategy for rational design of highly efficient HER catalysts.

7.
Angew Chem Int Ed Engl ; 59(5): 1961-1965, 2020 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-31674119

RESUMEN

The reaction of precursors containing both nitrogen and oxygen atoms with NiII under 500 °C can generate a N/O mixing coordinated Ni-N3 O single-atom catalyst (SAC) in which the oxygen atom can be gradually removed under high temperature due to the weaker Ni-O interaction, resulting in a vacancy-defect Ni-N3 -V SAC at Ni site under 800 °C. For the reaction of NiII with the precursor simply containing nitrogen atoms, only a no-vacancy-defect Ni-N4 SAC was obtained. Experimental and DFT calculations reveal that the presence of a vacancy-defect in Ni-N3 -V SAC can dramatically boost the electrocatalytic activity for CO2 reduction, with extremely high CO2 reduction current density of 65 mA cm-2 and high Faradaic efficiency over 90 % at -0.9 V vs. RHE, as well as a record high turnover frequency of 1.35×105  h-1 , much higher than those of Ni-N4 SAC, and being one of the best reported electrocatalysts for CO2 -to-CO conversion to date.

8.
Kidney Blood Press Res ; 44(6): 1392-1403, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31639794

RESUMEN

BACKGROUND AND OBJECTIVES: Vitamin K (VK) plays a major role in modifying the binding of calcium in bones and blood vessels. Understanding the effect of VK on crystal formation in the kidney would contribute to advancing the treatment and prevention of kidney stones. METHODS: Rats were treated with vitamin K1 (VK1) for 8 weeks. VK1 levels were detected and crystal formation were observed. HK2 cells were exposed to calcium oxalate monohydrate crystals. Apoptosis and cell viability were detected. Crystal deposition was analyzed using atomic absorption assay. The adenovirus vectors expressing matrix Gla protein (MGP) and siMGP were constructed to elucidate the effect and mechanism of VK1 on crystal formation. MGP expression in vivo and in vitro was analyzed by Western blot. The mRNA levels of monocyte chemoattractant protein-1 (MCP-1) and collagen I was measured by semiquantitative RT-PCR. RESULTS: The concentrations of VK1 in whole blood and kidney tissues rose under treatment with VK1. Crystal formation was inhibited from the second to the 6th week, the frequency and quality of crystal formation decreased significantly, and the location of crystal formation was limited to a greater extent in the rats treated by VK1 compared to the control group. Warfarin treatment in the crystals-exposed HK2 cells significantly increased the number of crystals adhering to cells and the number of apoptotic cells and reduced cell viability. VK1 treatment reversed warfarin's above influence. VK1 inhibited the upregulations of MCP-1 and collagen I in kidney tissues under crystal load. VK1 treatment increased MGP expression in vivo and in vitro, and MGP is necessary for VK1 to play a role in crystal deposition in cells. CONCLUSIONS: VK1 treatment can inhibit the formation of renal crystals in vivo. VK1 increases MGP expression and functions through MGP to reduce crystal deposition in cells and provide cell protection. Our findings suggest that VK1 treatment could be a potential strategy for the treatment and prevention of nephrolithiasis.


Asunto(s)
Proteínas de Unión al Calcio/metabolismo , Proteínas de la Matriz Extracelular/metabolismo , Cálculos Renales/prevención & control , Riñón/metabolismo , Vitamina K 1/farmacología , Animales , Apoptosis , Proteínas de Unión al Calcio/efectos de los fármacos , Línea Celular , Supervivencia Celular , Proteínas de la Matriz Extracelular/efectos de los fármacos , Humanos , Riñón/patología , Nefrolitiasis/prevención & control , Ratas , Vitamina K 1/uso terapéutico , Warfarina/farmacología , Proteína Gla de la Matriz
9.
Prep Biochem Biotechnol ; 49(5): 453-458, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30896287

RESUMEN

Existing evidence has demonstrated liposomes as the gene transporter induce the cytotoxicity during the transfection process through several known pathways. In the present study, we investigated the possibility of siRNAs targeting 3-ß-hydroxysterol △-24-reductase (DHCR24), which encodes an enzyme catalyzing the last step of cholesterol biosynthesis, to suppress the liposome cytotoxicity induced by lipid-based transfection reagent in the neuroblastoma cell line N2A. We found that the siRNAs targeting DHCR24 mRNA protect cells from the liposome-induced cell death, probably through the effect of siDHCR24s on the reduction of the cellular cholesterol and decrease in the generation of reactive oxygen species (ROS). This suggests that siRNAs targeting DHCR24 or other methods that reduce the intracellular cholesterol levels might be a good strategy for avoiding the cytotoxicity of liposomes, without impairing its efficiency of gene-delivering.


Asunto(s)
Supervivencia Celular/genética , Colesterol/deficiencia , Liposomas/efectos adversos , Proteínas del Tejido Nervioso/genética , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/genética , Interferencia de ARN , Animales , Caveolina 1/genética , Línea Celular Tumoral , Regulación hacia Abajo , Ratones , ARN Mensajero/genética , ARN Interferente Pequeño/genética , Transfección/métodos
10.
J Integr Plant Biol ; 60(6): 448-454, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29424475

RESUMEN

Although it is known that in most angiosperms mitosis in early endosperm development is syncytial and synchronized, it is unclear how the synchronization is regulated. We showed previously that APC11, also named ZYG1, in Arabidopsis activates zygote division by interaction and degradation of cyclin B1. Here, we report that the mutation in APC11/ZYG1 led to unsynchronized mitosis and over-accumulation of cyclin B1-GUS in the endosperm. Mutations in two other APC subunits showed similar defects. Transgenic expression of stable cyclin B1 in the endosperm also caused unsynchronized mitosis. Further, downregulation of APC11 generated multi-nucleate somatic cells with unsynchronized mitotic division. Together, our results suggest that APC/C-mediated cyclin B1 degradation is critical for cell cycle synchronization.


Asunto(s)
Subunidad Apc11 del Ciclosoma-Complejo Promotor de la Anafase/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/citología , Arabidopsis/metabolismo , Ciclo Celular , Ciclina B/metabolismo , Endospermo/citología , Células Gigantes/citología , Proteolisis , Arabidopsis/genética , Endospermo/metabolismo , Células Gigantes/metabolismo , Plantas Modificadas Genéticamente
11.
Angew Chem Int Ed Engl ; 57(30): 9382-9386, 2018 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-29885267

RESUMEN

Two Pt single-atom catalysts (SACs) of Pt-GDY1 and Pt-GDY2 were prepared on graphdiyne (GDY)supports. The isolated Pt atoms are dispersed on GDY through the coordination interactions between Pt atoms and alkynyl C atoms in GDY, with the formation of five-coordinated C1 -Pt-Cl4 species in Pt-GDY1 and four-coordinated C2 -Pt-Cl2 species in Pt-GDY2. Pt-GDY2 shows exceptionally high catalytic activity for the hydrogen evolution reaction (HER), with a mass activity up to 3.3 and 26.9 times more active than Pt-GDY1 and the state-of-the-art commercial Pt/C catalysts, respectively. Pt-GDY2 possesses higher total unoccupied density of states of Pt 5d orbital and close to zero value of Gibbs free energy of the hydrogen adsorption (|ΔGPtH* |) at the Pt active sites, which are responsible for its excellent catalytic performance. This work can help better understand the structure-catalytic activity relationship in Pt SACs.

12.
Plant J ; 86(2): 161-74, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26952278

RESUMEN

As the start of a new life cycle, activation of the first division of the zygote is a critical event in both plants and animals. Because the zygote in plants is difficult to access, our understanding of how this process is achieved remains poor. Here we report genetic and cell biological analyses of the zygote-arrest 1 (zyg1) mutant in Arabidopsis, which showed zygote-lethal and over-accumulation of cyclin B1 D-box-GUS in ovules. Map-based cloning showed that ZYG1 encodes the anaphase-promoting complex/cyclosome (APC/C) subunit 11 (APC11). Live-cell imaging studies showed that APC11 is expressed in both egg and sperm cells, in zygotes and during early embryogenesis. Using a GFP-APC11 fusion construct that fully complements zyg1, we showed that GFP-APC11 expression persisted throughout the mitotic cell cycle, and localized to cell plates during cytokinesis. Expression of non-degradable cyclin B1 in the zygote, or mutations of either APC1 or APC4, also led to a zyg1-like phenotype. Biochemical studies showed that APC11 has self-ubiquitination activity and is able to ubiquitinate cyclin B1 and promote degradation of cyclin B1. These results together suggest that APC/C-mediated degradation of cyclin B1 in Arabidopsis is critical for initiating the first division of the zygote.


Asunto(s)
Ciclosoma-Complejo Promotor de la Anafase/metabolismo , Arabidopsis/citología , Ciclina B1/metabolismo , Semillas/citología , Arabidopsis/metabolismo , División Celular , Citocinesis , Mutación , Proteolisis , Semillas/metabolismo , Ubiquitinación
13.
J Urol ; 196(1): 118-23, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26812303

RESUMEN

PURPOSE: SLC26A6 is a multifunctional anion transporter with a critical physiological role in the transport of oxalate anions. Recognizing a genetic variant of SLC26A6 would advance our understanding of oxalate transport in the formation of calcium oxalate stones. MATERIALS AND METHODS: All nsSNPs (nonsynonymous single nucleotide polymorphisms) reported in human SLC26A6 were investigated using 4 in silico tools, including SIFT (Sorting Intolerant From Tolerant), PROVEAN (Protein Variation Effect Analyzer), PhD-SNP (Predictor of human Deleterious Single Nucleotide Polymorphisms) and MutPred. A total of 426 subjects, including 225 with kidney stones and 201 healthy controls, were included in study to genotype the candidate disease associated nsSNP using allele specific polymerase chain reaction. Furthermore, the structural consequences due to the mutation were assessed using homology modeling and molecular dynamics simulation methods. RESULTS: The nsSNP rs184187143 was identified as a more probable disease associated variant in the SLC26A6 gene by in silico screening. The C allele carrier showed a 6.1-fold increased kidney stone risk compared with G allele carriers in the nsSNP (OR 6.1, 95% CI 1.36-27.38, p = 0.007). We found that the mutation from arginine to glycine leads to the loss of 2 hydrogen bonds and to an unstable structure in the STAS domain of SLC26A6. CONCLUSIONS: Our results indicate that the variant G539R in the SLC26A6 gene is associated with kidney stone risk, providing a clear clue to further achieve insight into oxalate transport in kidney stone formation.


Asunto(s)
Predisposición Genética a la Enfermedad , Cálculos Renales/genética , Proteínas de Transporte de Membrana/genética , Polimorfismo de Nucleótido Simple , Adulto , Anciano , Estudios de Casos y Controles , Bases de Datos Factuales , Femenino , Marcadores Genéticos , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Simulación de Dinámica Molecular , Mutación , Transportadores de Sulfato
14.
Angew Chem Int Ed Engl ; 55(5): 1710-3, 2016 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-26695560

RESUMEN

Inorganic nanowire arrays hold great promise for next-generation energy storage and conversion devices. Understanding the growth mechanism of nanowire arrays is of considerable interest for expanding the range of applications. Herein, we report the solution-liquid-solid (SLS) synthesis of hexagonal nickel selenide nanowires by using a nonmetal molecular crystal (selenium) as catalyst, which successfully brings SLS into the realm of conventional low-temperature solution synthesis. As a proof-of-concept application, the NiSe nanowire array was used as a catalyst for electrochemical water oxidation. This approach offers a new possibility to design arrays of inorganic nanowires.

15.
Angew Chem Int Ed Engl ; 55(7): 2488-92, 2016 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-26757358

RESUMEN

Developing highly active catalysts for the oxygen evolution reaction (OER) is of paramount importance for designing various renewable energy storage and conversion devices. Herein, we report the synthesis of a category of Co-Pi analogue, namely cobalt-based borate (Co-Bi ) ultrathin nanosheets/graphene hybrid by a room-temperature synthesis approach. Benefiting from the high surface active sites exposure yield, enhanced electron transfer capacity, and strong synergetic coupled effect, this Co-Bi NS/G hybrid shows high catalytic activity with current density of 10 mA cm(-2) at overpotential of 290 mV and Tafel slope of 53 mV dec(-1) in alkaline medium. Moreover, Co-Bi NS/G electrocatalysts also exhibit promising performance under neutral conditions, with a low onset potential of 235 mV and high current density of 14.4 mA cm(-2) at 1.8 V, which is the best OER performance among well-developed Co-based OER electrocatalysts to date. Our finding paves a way to develop highly active OER electrocatalysts.

16.
Angew Chem Int Ed Engl ; 54(49): 14710-4, 2015 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26437900

RESUMEN

Designing highly efficient electrocatalysts for oxygen evolution reaction (OER) plays a key role in the development of various renewable energy storage and conversion devices. In this work, we developed metallic Co4N porous nanowire arrays directly grown on flexible substrates as highly active OER electrocatalysts for the first time. Benefiting from the collaborative advantages of metallic character, 1D porous nanowire arrays, and unique 3D electrode configuration, surface oxidation activated Co4N porous nanowire arrays/carbon cloth achieved an extremely small overpotential of 257 mV at a current density of 10 mA cm(-2), and a low Tafel slope of 44 mV dec(-1) in an alkaline medium, which is the best OER performance among reported Co-based electrocatalysts to date. Moreover, in-depth mechanistic investigations demonstrate the active phases are the metallic Co4N core inside with a thin cobalt oxides/hydroxides shell during the OER process. Our finding introduces a new concept to explore the design of high-efficiency OER electrocatalysts.

17.
Pestic Biochem Physiol ; 115: 53-7, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25307466

RESUMEN

Three planthopper species, the brown planthopper (BPH), Nilaparvata lugens Stål, the white-backed planthopper (WBPH), Sogatella furcifera Horvath, and the small brown planthopper (SBPH), Laodelphax striatella Fallén, often co-occur in rice grown regions of China. The present investigation examined effects of two pesticides, triazophos (TZP) and jinggangmycin (JGM) (a fungicide), on reproduction of BPH, WBPH, and SBPH. The results showed that TZP stimulated the fecundity of the three planthopper species. Interestingly, JGM stimulated the fecundity of BPH but suppressed the fecundity of WBPH. In addition, TZP and JGM had a significant effect on the preoviposition period (PVD), the oviposition period (OPD), and the longevity of adult females (LAF) of BPH and WBPH. Based on these findings, to avoid resurgence occurrence of planthoppers, we suggest that the application of TZP should be banned in rice fields, that JGM should be used to control rice sheath blight at the early growth stages of rice (with WBPH occurrence and without BPH occurrence).


Asunto(s)
Hemípteros/efectos de los fármacos , Hemípteros/fisiología , Plaguicidas/farmacología , Animales , China , Femenino , Fertilidad/efectos de los fármacos , Masculino , Oryza/crecimiento & desarrollo , Oryza/parasitología , Enfermedades de las Plantas/parasitología , Reproducción/efectos de los fármacos
18.
Pestic Biochem Physiol ; 114: 97-101, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25175656

RESUMEN

The pesticide-induced stimulation of reproduction in pests is one of the most important mechanisms of pest resurgence. There have been numerous reports on the insecticide-induced stimulation of reproduction. However, the relationship between pesticide application method and pest resurgence (stimulation of reproduction) has received little attention. Here, we studied the effect of two treatment methods, triazophos (TZP) and jinggangmycin (JGM), on the protein content in the ovaries and fat bodies of the brown planthopper (BPH) Nilaparvata lugens Stål. The results showed that pesticide treatment methods significantly affected the protein content in the ovaries and fat bodies of BPH. In addition, grand means (means of main effect) of the protein content at 2 and 3 days after emergence (2 and 3 DAE) for foliar sprays was significantly higher than that observed after topical treatments, which increased by 23.9% (from 1.42 to 1.76) and 8.82% (from 4.42 to 4.81), respectively. No significant differences on the protein content in the ovaries and fat bodies for the JGM topical treatment were observed compared with controls. However, the protein content for JGM foliar sprays was significantly higher than that for the controls. The protein contents in both topical and spray treatments of TZP were significantly higher than those of the controls. Ovarian protein is mainly yolk protein. There is a positive correlation between ovarian protein content and the number of eggs laid. These findings show that foliar spray of the pesticides promotes the resurgence of BPH. Therefore, the foliar spray of some pesticides, such as JGM, should be avoided for the control of pests, which is the sideeffects of the fungicide on non-target insect pests' occurrence.


Asunto(s)
Fungicidas Industriales/farmacología , Hemípteros/efectos de los fármacos , Inositol/análogos & derivados , Proteínas de Insectos/metabolismo , Insecticidas/farmacología , Organotiofosfatos/farmacología , Triazoles/farmacología , Animales , Cuerpo Adiposo/efectos de los fármacos , Cuerpo Adiposo/metabolismo , Femenino , Hemípteros/fisiología , Inositol/farmacología , Ovario/efectos de los fármacos , Ovario/metabolismo
19.
J Matern Fetal Neonatal Med ; 37(1): 2337708, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38735865

RESUMEN

BACKGROUND: Presently, the efficacy of neonatal resuscitation techniques via interventions such as oral, nasal, and endotracheal suction for preventing meconium aspiration syndrome (MAS) after delivery has not been satisfactory. OBJECTIVE: This study aimed to investigate the role of intratracheal instillation of budesonide on oxidative stress in MAS. METHODS: Sixty-two neonates with MAS admitted to Huai'an Maternity and Child Healthcare Hospital from January 2018 to June 2020 were divided into a study group (intratracheal instillation of 2 ml budesonide suspension; n = 31) and a control group (intratracheal instillation of 2 ml normal saline; n = 31). Collect data from two groups of patients and evaluate clinical outcomes, including oxygenation index (OI), as well as serum total oxidant status (TOS), total antioxidant capacity (TAC), oxidative stress index (OSI) and 8-Isoprostane before treatment and 72h after admission. RESULTS: We found no statistical differences in mortality, complication rate, total oxygen inhalation time, OI before treatment and 72h after admission between the two groups of neonates with MAS, while the duration of invasive respiratory support in the study group was significantly shorter than in the control group. Also, serum TAC, TOS, OSI and 8-isoprostane levels were not statistically different before treatment between the two groups. After 72h of admission, OSI and 8-Isoprostane in neonates with MAS in the study group were much lower than those in the control group. TOS, OSI, 8-Isoprostane in the control group and 8-Isoprostane in the study group were significantly higher than those before treatment. As for TAC and TOS, no significant differences were observed between the two groups. CONCLUSION: Intratracheal instillation of budesonide was shown to alleviate oxidative stress and shorten invasive ventilation time in neonates with MAS.


Asunto(s)
Budesonida , Dinoprost/análogos & derivados , Síndrome de Aspiración de Meconio , Estrés Oxidativo , Humanos , Síndrome de Aspiración de Meconio/tratamiento farmacológico , Recién Nacido , Estrés Oxidativo/efectos de los fármacos , Budesonida/administración & dosificación , Femenino , Masculino , Solución Salina/administración & dosificación , Instilación de Medicamentos , Estudios de Casos y Controles
20.
Adv Mater ; : e2411942, 2024 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-39340286

RESUMEN

Alkaline hydrogen evolution reaction (HER) has great potential in practical hydrogen production but is still limited by the lack of active and stable electrocatalysts. Herein, the efficient water dissociation process, fast transfer of adsorbed hydroxyl and optimized hydrogen adsorption are first achieved on a cooperative electrocatalyst, named as Ru-Sn/SnO2 NS, in which the Ru-Sn dual metal sites and SnO2 heterojunction are constructed based on porous Ru nanosheet. The density functional theory (DFT) calculations and in situ infrared spectra suggest that Ru-Sn dual sites can optimize the water dissociation process and hydrogen adsorption, while the existence of SnO2 can induce the unique hydroxyl spillover effect, accelerating the hydroxyl transfer process and avoiding the poison of active sites. As results, Ru-Sn/SnO2 NS display remarkable alkaline HER performance with an extremely low overpotential (12 mV at 10 mA cm-2) and robust stability (650 h), much superior to those of Ru NS (27 mV at 10 mA cm-2 with 90 h stability) and Ru-Sn NS (16 mV at 10 mA cm-2 with 120 h stability). The work sheds new light on designing of efficient alkaline HER electrocatalyst.

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