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1.
Zhongguo Zhong Yao Za Zhi ; 49(5): 1144-1153, 2024 Mar.
Artículo en Chino | MEDLINE | ID: mdl-38621961

RESUMEN

Agaricus blazei is a rare medicinal and edible fungus with a crispy taste and delicious flavor. Both fruiting body and mycelium are rich in polysaccharides, sterols, terpenoids, peptides, lipids, polyphenols, and other active ingredients, which have strong pharmacological activities such as anti-tumor, lipid-lowering, glucose-lowering, immunomodulation, optimization of intestinal flora, and anti-oxidation. Therefore, it is a kind of fungal resource with a great prospect of edible and medicinal development. Among the reported chemical components of A. blazei, blazeispirol is a series of sterol compounds unique to A. blazei, which has a spiral structure and is different from classical steroids. It is an important active ingredient found in the mycelium of A. blazei and has significant hepatoprotective activity. It can be used as a phylogenetic and chemotaxonomic marker of A. blazei strains and is considered an excellent lead compound for drug development. According to the skeleton structure characteristics, the 17 discovered blazeispirol compounds can be divided into two types: blazeispirane and problazeispirane. In order to further explore the resource of blazeispirol compounds of A. blazei, the discovery, isolation, structure, biological activity, and biosynthetic pathways of blazeispirol compounds of A. blazei were systematically reviewed. Besides, the metabolic regulation strategies related to the fermentation synthesis of blazeispirol A by A. blazei were discussed. This review could provide a reference for the efficient synthesis and development of blazeispirol compounds, the research and development of related drugs and functional foods, and the quality improvement of A. blazei and other medicinal and edible fungi resources and derivatives.


Asunto(s)
Agaricus , Neoplasias , Filogenia , Polisacáridos , Esteroides , Agaricus/química , Agaricus/metabolismo
2.
J Adv Res ; 57: 107-117, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37075861

RESUMEN

INTRODUCTION: Viruses are abundant and ecologically significant in marine ecosystems. However, the virome of deep-sea sediments is not extensively investigated. OBJECTIVES: To explore the distribution pattern of deep-sea viruses on a global scale, the viromes of DNA viruses isolated from 138 sediments of 5 deep-sea ecosystems were characterized. METHODS: The viral particles were purified from each sediment sample. Then the viral DNAs were extracted and subjected to viral metagenomic analysis. RESULTS: Here, we constructed a global deep-sea environmental virome dataset by analyzing the viral DNA of 138 sediment samples. A total of 347,737 viral operational taxonomic units (vOTUs) were identified, of which 84.94% were hitherto unknown, indicating that deep sea was a reservoir of novel DNA viruses. Furthermore, circular viral genome analysis revealed 98,581 complete genomes. The classified vOTUs included eukaryotic (44.55%) and prokaryotic (25.75%) viruses, and were taxonomically assigned to 63 viral families. The composition and abundance of the deep-sea sediment viromes were dependent on the deep-sea ecosystem as opposed to geographical region. Further analysis revealed that the viral community differentiation in different deep-sea ecosystems was driven by the virus-mediated energy metabolism. CONCLUSION: Our findings showed that deep-sea ecosystems are a reservoir of novel DNA viruses and the viral community is shaped by the environmental characteristics of deep-sea ecosystems, thus presenting critical information for determining the ecological significance of viruses in global deep-sea ecosystems.


Asunto(s)
Ecosistema , Viroma , Humanos , Virus ADN/genética , ADN Viral/genética , Metabolismo Energético
3.
Biomater Sci ; 11(21): 6977-7002, 2023 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-37695360

RESUMEN

The use of biomaterials in biomedicine and healthcare has increased in recent years. Macrophages are the primary immune cells that induce inflammation and tissue repair after implantation of biomaterials. Given that macrophages exhibit high heterogeneity and plasticity, the influence of biomaterials on macrophage phenotype should be considered a crucial evaluation criterion during the development of novel biomaterials. This review provides a comprehensive summary of the physicochemical, biological, and dynamic characteristics of biomaterials that drive the regulation of immune responses in macrophages. The mechanisms involved in the interaction between macrophages and biomaterials, including endocytosis, receptors, signalling pathways, integrins, inflammasomes and long non-coding RNAs, are summarised in this review. In addition, research prospects of the interaction between macrophages and biomaterials are discussed. An in-depth understanding of mechanisms underlying the spatiotemporal changes in macrophage phenotype induced by biomaterials and their impact on macrophage polarization can facilitate the identification and development of novel biomaterials with superior performance. These biomaterials may be used for tissue repair and regeneration, vaccine or drug delivery and immunotherapy.

4.
ACS Appl Mater Interfaces ; 15(37): 43745-43755, 2023 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-37695646

RESUMEN

TiNb2O7 has attracted extensive attention from lithium-ion battery researchers due to its superior specific capacity and safety. However, its poor ion conductivity and electron conductivity hinder its further development. To improve the ion/electron transport of TiNb2O7, we report that chlorine doping and oxygen vacancy engineering regulate the energy band and crystal structure simultaneously through a simple solid-phase method. NH4Cl was used to realize Cl- doping and oxygen vacancy production. A Rietveld refinement demonstrates an effective substitution of Cl in the O sites of Nb-O octahedra, with an enlarged crystal plane spacing. The oxygen vacancies provide more active sites for lithium intercalation. The diffusion coefficient of Li+ is inceased from 2.39 × 10-14 to 1.50 × 10-13 cm2 s-1, which reveals the positive influence of Cl- doping and oxygen vacancies on the promoted Li+ transport behavior. Charge compensation is introduced by the doping of Cl- and the generation of oxygen vacancies, leading to the formation of Ti3+ and Nb4+ and the adjustment of the electronic structure. DFT calculations reveal that TiNb2O7 with Cl- doping and an O vacancy shows a metallic property with a finite value at the Fermi level, which is conducive to electron transfer in the electrode material. Benefiting from these advantages, the modified TiNb2O7 presents superior rate performance with a commendable capacity of 172.82 mAh g-1 at 50 C. This work provides guidance to design high-performance anode materials for high-rate lithium-ion batteries.

5.
J Clin Transl Res ; 9(3): 160-167, 2023 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-37457545

RESUMEN

Background: Obstructive severe acute biliary pancreatitis (SABP) is a clinical emergency with a high rate of mortality that can be alleviated by endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangial drainage (PTCD) selectively. However, the optimal timing of ERCP and PTCD requires elucidation. Aim: The aim of this study was to evaluate outcome parameters in patients with SABP subjected to ERCP and PTCD compared to SABP patients who were not subjected to any form of invasive intervention. Methods: A total of 62 patients with obstructive SABP who had been treated from July 2013 to July 2019 were included in this retrospective case-control study and stratified into a PTCD group (N = 22), ERCP group (N = 24), and conservative treatment group (N = 16, control). Patients in the PTCD and ERCP groups were substratified into early (≤72 h) and delayed (>72 h) treatment groups based on the timing of the intervention after diagnosis. Clinical chemistry, hospitalization days, liver function, abdominal pain, and complications were determined to assess the treatment efficacy and safety of each modality and to establish the optimal timing for PTCD and ERCP. Results: The average hospitalization time, time to abdominal pain relief, and time to normalization of hematological and clinical chemistry parameters (leukocyte count, amylase, alanine transaminase [ALT], and total bilirubin [TBiL]) were shorter in the PTCD and ERCP groups compared to the conservative treatment group (p < 0.05). The average hospitalization time in the ERCP group (16.7 ± 4.0 d) was shorter compared to the PTCD group (19.6 ± 4.3 d) (p < 0.05). Compared to the conservative treatment group (62.5%), there were more complications in patients treated with ERCP and PTCD (p < 0.05). In the early ERCP group, the average hospitalization time (13.9 ± 3.3 d) and the time to normalization of leukocyte count (6.3 ± 0.9 d) and TBiL (9.1 ± 2.0 d) were lower than in the delayed ERCP group (18.6 ± 4.1 d, 9.9 ± 2.4 d, 11.8 ± 2.9 d, respectively) and early PTCD group (16.4 ± 3.7 d, 8.5 ± 2.1 d, 10.9 ± 3.1 d, respectively) (p < 0.05). In the delayed ERCP group, the average hospitalization time (18.6 ± 4.1 d) and ALT recovery time (12.2 ± 2.6 d) were lower than in the delayed PTCD group (21.9 ± 4.3 d and 14.9 ± 3.9 d, respectively) (p < 0.05). Conclusions: ERCP and PTCD effectively relieve SABP-associated biliary obstruction with comparable overall incidence of complications. It is recommended that ERCP is performed within 72 h after diagnosis; and PTCD drainage may be considered an alternative approach in cases where patients are unable or unwilling to undergo ERCP, or when ERCP is unsuccessful. Relevance for Patients: ERCP and PTCD in patients with obstructive SABP can resolve biliary obstruction and delay progression of the disease. Performing ERCP and PTCD within 72 h (i.e., optimal treatment time window) can be beneficial to patients, especially in terms of post-operative recovery. Visual biliary endoscopy (oral or percutaneous transhepatic) may be used for concomitant therapeutic interventions in the biliary system.

6.
Adv Sci (Weinh) ; 10(3): e2205681, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36446629

RESUMEN

Learning and studying the structure-activity relationship in the bio-enzymes is conducive to the design of nanozymes for energy and environmental application. Herein, Fe single-atom nanozymes (Fe-SANs) with Fe-N5 site, inspired by the structure of cytochromes P450 (CYPs), are developed and characterized. Similar to the CYPs, the hyperoxide can activate the Fe(III) center of Fe-SANs to generate Fe(IV)O intermediately, which can transfer oxygen to the substrate with ultrafast speed. Particularly, using the peroxymonosulfate (PMS)-activated Fe-SANs to oxidize sulfamethoxazole, a typical antibiotic contaminant, as the model hyperoxides activation reaction, the excellent activity within 284 min-1 g-1 (catalyst) mmol-1 (PMS) oxidation rate and 91.6% selectivity to the Fe(IV)O intermediate oxidation are demonstrated. More importantly, instead of promoting PMS adsorption, the axial N ligand modulates the electron structure of FeN5 SANs for the lower reaction energy barrier and promotes electron transfer to PMS to produce Fe(IV)O intermediate with high selectivity. The highlight of the axial N coordination in the nanozymes in this work provides deep insight to guide the design and development of nanozymes nearly to the bio-enzyme with excellent activity and selectivity.


Asunto(s)
Compuestos Férricos , Peróxidos , Ligandos , Oxidación-Reducción
7.
Future Oncol ; 18(30): 3463-3470, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36069254

RESUMEN

Colorectal cancer is one of the most malignant cancers worldwide, and efforts have been made to elucidate the mechanism of colorectal carcinogenesis. Cellular senescence is a physiological process in cell life, but it is also found in cancer initiation and progression. Lines of evidence show that senescence may influence the development and progression of colorectal carcinogenesis. Here, the authors review the characteristics of senescence and the recent findings of a relationship between senescence and colorectal cancer.


Cancer is a leading cause of death worldwide; out of the top ten most common cancers in 2020, the incidence and mortality rate of colorectal cancer (CRC) ranked third and second, respectively. Based on statistics, it was estimated that more than 1.9 million CRC cases occurred in 2020. In terms of CRC, a prominent risk factor is age, and studies suggest that the aging process plays a role in CRC initiation and progression. This review discusses how aging contributes to CRC carcinogenesis and summarizes recent findings on potential therapeutics.


Asunto(s)
Neoplasias Colorrectales , Humanos , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Senescencia Celular , Carcinogénesis
8.
ACS Appl Mater Interfaces ; 14(27): 30724-30734, 2022 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-35766357

RESUMEN

The oxygen reduction reaction (ORR) activity of the Fe/N/Carbon catalysts derived from the pyrolysis of zeolitic-imidazolate-framework-8 (ZIF-8) has been still lower than that of commercial Pt-based catalysts utilized in the proton exchange membrane fuel cells (PEMFCs) due to low density of accessible active sites. In this study, an efficient carbon-supporting strategy is developed to enhance the ORR efficiency of the ZIF-derived Fe/N/Carbon catalysts by increasing the accessible active site density. The enhancement lies in (i) improving the accessibility of active sites via converting dodecahedral particles to graphene-like layered materials and (ii) enhancing the density of FeNx active sites via suppressing the formation of nanoparticles as well as providing extra spaces to host active sites. The optimized and efficient Fe/N/Carbon catalyst shows a half-wave potential (E1/2) of 0.834 V versus reversible hydrogen electrode in acidic media and produces a peak power density of 0.66 W cm-2 in an air-fed PEMFC at 2 bar backpressure, outperforming most previously reported Pt-free ORR catalysts. Finally, the general applicability of the carbon-supporting strategy is confirmed using five different commercial carbon blacks. This work provides an effective route to derive Fe/N/Carbon catalysts exhibiting a higher power density in PEMFCs.

9.
Pharm Biol ; 60(1): 774-784, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35361038

RESUMEN

CONTEXT: Tadehagi triquetrum (Linn.) Ohashi (Fabaceae) (TT), is a traditional herbal medicine used especially in China's ethnic-minority communities, such as the Zhuang, Dai, Li and Wa aeras. As an ethnic medicine, it has long been used to treat various diseases. OBJECTIVE: This review summarised the phytochemical and pharmacological progress on TT from 1979 to October, 2021 by highlighting its chemical classification, structural features, pharmacological applications and folk applications to provide inspirations and suggestions for accelerating further research of this traditional phytomedicine. METHODS: The information on TT in this article has been obtained using these multiple scientific databases including Scifinder, Web of Science, ScienceDirect, Wiley, ACS publications, Springer, PubMed, China Knowledge Resource Integrated Database from the China National Knowledge Infrastructure (CNKI), Google Scholar and Baidu Scholar. Some information was also collected from classic literature on traditional Chinese medicines. RESULTS: More than 70 compounds have been isolated and reported from TT to date by the comprehensive analysis of the current literature. A large number of traditional uses and pharmacological studies have exhibited diversified bioactivities of various TT extracts and its metabolites, including anti-inflammatory, antimicrobial, anti-hepatitis B virus, hepatoprotective, insecticidal, etc. CONCLUSIONS: As a famous traditional medicine with a long history, TT has various medicinal uses and some of them have been supported by modern pharmacological researches. Further detailed studies on the action mechanisms, pharmacodynamics and structure-function relationships of single compounds or active constituents from TT are also required.


Asunto(s)
Fabaceae , Fitoterapia , China , Etnofarmacología , Medicina Tradicional China
10.
Burns ; 48(4): 880-895, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35410697

RESUMEN

BACKGROUND: Tranilast (N-[3',4'-dimethoxycinnamoyl]-anthranilic acid) is an analog of a tryptophan metabolite. It was identified with anti-inflammatory and antifibrotic activities, and used in the treatment of a variety of diseases, such as anti - allergy, bronchial asthma, and hypertrophic scars. As a drug with few adverse reactions, tranilast has attracted great attention, but its application is limited due to the uncertainty of dosages and mechanisms. In this study, the protection effects of different doses of tranilast on smoke inhalation mediated lung injury on rats, and on the damage of three kinds of lung cells in vitro were investigated. METHOD: In vivo, Sprague-Dawley rats were randomly divided into sham group, smoke group (rats were exposed to pine sawdust smoke three times, each time for 5 min), different doses of tranilast treatment group (doses were 100 mg/kg, 200 mg/kg and 300 mg/kg, ip.) and placebo group. After 1, 3 and 7 days, pulmonary function, pathologic injury by HE staining, cytokines and oxidative stress level by kits were determined. At 7days, lung fibrosis was assessed by Masson's trichrome staining and the level of hydroxyproline (HYP). In vitro, three kinds of lung cells from normal rats were isolated: type II alveolar epithelial cells (AT-II), pulmonary microvascular endothelial cells (PMVECs) and pulmonary fibroblasts (PFs). To investigate the potential effects of tranilast on cell proliferation, cell cycle and cytokine production of three kinds of lung cells exposed to smoke. RESULTS: Compared with smoke group and placebo group, tranilast treatment significantly reduced histopathological changes (such as pulmonary hemorrhage, edema and inflammatory cell infiltration, etc.), significantly reduced histopathological score (p < 0.05), increased arterial oxygen partial pressure, and decreased the levels of IL-1ß, TNF-α, TGF-ß1 (p < 0.05), oxidative stress and the expression of nuclear transcription factor κB (NF-κB) smoke exposed rats (p < 0.01). In particular, the effect of 200 mg/kg dose was more prominent. In vitro, smoke induced AT-II and PMVECs apoptosis, improved PFs proliferation (p < 0.01), activity of SOD and decreased the content of MDA (p < 0.01). However, tranilast seems to be turning this trend well. The inflammatory factor IL-11ß, TNF-α and TGF-ß1, and the expression of NF-κB were significantly lower in the tranilast treatment than in the smoke group (p < 0.01). CONCLUSION: This study indicates that tranilast had a protective effect on acute respiratory distress syndrome and early pulmonary fibrosis of rats in vivo. In addition, tranilast promotes proliferation of AT-II and PMVECs but inhibits PFs proliferation, down-regulates secretion of inflammatory cytokines and alleviates oxidative stress of AT-II, PMVECs and PFs after smoke stimuli in vitro.


Asunto(s)
Quemaduras , Fibrosis Pulmonar , Síndrome de Dificultad Respiratoria , Lesión por Inhalación de Humo , Animales , Citocinas/metabolismo , Células Endoteliales/metabolismo , Humanos , Pulmón/metabolismo , FN-kappa B/metabolismo , Fibrosis Pulmonar/tratamiento farmacológico , Fibrosis Pulmonar/metabolismo , Fibrosis Pulmonar/prevención & control , Ratas , Ratas Sprague-Dawley , Factor de Crecimiento Transformador beta1/metabolismo , Factor de Necrosis Tumoral alfa , ortoaminobenzoatos
11.
Anal Chem ; 93(29): 10310-10316, 2021 07 27.
Artículo en Inglés | MEDLINE | ID: mdl-34260216

RESUMEN

DNA methyltransferases may function as important biomarkers of cancers and genetic diseases. Herein, we develop a dye-sensitized and gold plasmon-enhanced cathodic photoelectrochemical (PEC) biosensor on the basis of p-type covalent organic polymers (COPs) for the signal-on measurement of M.SssI methyltransferase (M.SssI MTase). The cathodic PEC biosensor is constructed by the in situ growth of p-type COP films onto a glass coated with indium tin oxide and the subsequent assembly of biotin- and HS-labeled double-stranded DNA (dsDNA) probes onto the COP film via biotin-streptavidin interaction. The dsDNA probe contains the recognition sequence of M.SssI MTase. The COP thin films possess a porous ultrathin nanosheet structure with abundant active sites, facilitating the generation of a high photocurrent compared with the hydrothermally synthesized ones. The presence of DNA methyltransferases can prevent the digestion of restriction endonuclease HpaII, consequently inducing the introduction of gold nanoparticles (AuNPs) to the dsDNA probes via the S-Au bond and the intercalation of rhodamine B (RhB) into the DNA grooves to produce a high photocurrent due to the dye-photosensitized enhancement and AuNP-mediated surface plasmon resonance. However, in the absence of M.SssI MTase, HpaII digests the dsDNA probes, and neither AuNPs nor RhB can be introduced onto the electrode surface, leading to a low photocurrent. This cathodic PEC biosensor possesses high sensitivity and good selectivity, and it can screen the inhibitors and detect M.SssI MTase in serum as well.


Asunto(s)
Técnicas Biosensibles , Nanopartículas del Metal , Técnicas Electroquímicas , Electrodos , Oro , Metiltransferasas
12.
Inorg Chem ; 60(4): 2563-2572, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33494596

RESUMEN

Recently, metal-organic frameworks (MOFs) have been investigated as potential materials for CO2 capture and light hydrocarbon storage/separation due to their high porosity, large surface area, and tunable skeleton structures. In this work, the six cobalt-based MOFs 1-6 were successfully synthesized under solvothermal conditions by a mixed-ligand strategy. 1 and 2 have the same framework structure with a topology of {42·5}2{44·510·67·76·8}, while the structures of the 3-6 frameworks are the same with a topology of {42·5}2{44·510·69·74·8}. The adsorption properties of these MOFs for CO2 and C2 hydrocarbons were then investigated, and the effect of the functional groups was discussed. The results revealed that the introduction of amino and bromo groups could effectively strengthen the adsorption performance.

13.
Org Lett ; 22(24): 9462-9467, 2020 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-33275440

RESUMEN

Through the development of ligands and reaction conditions, the Rh(III)-catalyzed selective annulation of benzamides with internal alkynes has been achieved to the formation of O-cyclized isochromen-imines. Various substituents are well-tolerated under mild reaction conditions. Density functional theory calculations indicate that silver carbonate could act as a Lewis acid to assist the ligand to improve the chemical selectivity of the reaction in a catalytic system.

14.
Dalton Trans ; 49(43): 15473-15480, 2020 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-33141127

RESUMEN

Two series of lanthanide-based metal-organic frameworks, namely {[Ln(BIPA-TC)0.5(DMA)2(NO3)]·DMA·H2O}n (1-Ln, Ln = Eu, Dy, Sm, Nd) and {[Ln2(BIPA-TC)1.5(DMA)3(H2O)2]·2DMA·2H2O}n (2-Ln, Ln = Eu, Dy, Sm, Nd), were successfully constructed via a solvent regulation strategy based on a π-electron rich tetra-carboxylate ligand (H4BIPA-TC). 1-Ln shows a 4-connected lvt topology with the point symbol of {42·84}, but 2-Ln displays a new 4,4,6-connected wxk1 topology with the point symbol of {43·83}4{46·66·83}2{86}. The solid-state luminescence property and the microporous nature of Eu-MOFs (1-Eu and 2-Eu) indicate that they can potentially be used as luminescent sensors. Fluorescence measurements indicate that Fe3+ exhibits the quenching effect for 1-Eu with the quenching efficiency of 93.1%. 2-Eu is the first MOF sensor for Mg2+ with the lowest detection limit of 1.53 × 10-10 mol L-1 and displays good recyclable capability. Simultaneously, in the presence of other metal ions (Ca2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Pd2+, Al3+, Cr3+and Fe3+), 2-Eu can maintain the selective sensing of Mg2+, indicating its potential for Mg2+ turn-on sensing.

15.
Drug Dev Res ; 81(8): 1037-1047, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32754990

RESUMEN

In this study, a series of new flavones (2-phenyl-chromone), 2-naphthyl chromone, 2-anthryl-chromone, or 2-biphenyl-chromone derivatives containing 6 or 7-substituted tertiary amine side chain were designed, synthesized, and evaluated in acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition. The results indicated that the alteration of aromatic ring connecting to chromone scaffold brings about a significant impact on biological activity. Compared with flavones, the inhibitory activity of 2-naphthyl chromone, 2-anthryl-chromone derivatives against AChE significantly decreased, while that of 2-biphenyl chromone derivatives with 7-substituted tertiary amine side chain is better than relative flavones derivatives. For all new synthesized compounds, the position of tertiary amine side chain obviously influenced the activity of inhibiting AChE. The results above provide great worthy information for the further development of new AChE inhibitors. Among the newly synthesized compounds, compound 5a is potent in AChE inhibition (IC50 = 1.29 ± 0.10 µmol/L) with high selectivity for AChE over BChE (selectivity ratio: 27.96). An enzyme kinetic study of compound 5a suggests that it produces a mixed-type inhibitory effect against AChE.

16.
Small ; 16(31): e2002203, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32521114

RESUMEN

The rational design of catalytically active sites in porous materials is essential in electrocatalysis. Herein, atomically dispersed Fe-Nx sites supported by hierarchically porous carbon membranes are designed to electrocatalyze the hydrazine oxidation reaction (HzOR), one of the key techniques in electrochemical nitrogen transformation. The high intrinsic catalytic activity of the Fe-Nx single-atom catalyst together with the uniquely mixed micro-/macroporous membrane support positions such an electrode among the best-known heteroatom-based carbon anodes for hydrazine fuel cells. Combined with advanced characterization techniques, electrochemical probe experiments, and density functional theory calculation, the pyrrole-type FeN4 structure is identified as the real catalytic site in HzOR.

17.
Stem Cell Res Ther ; 10(1): 233, 2019 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-31375149

RESUMEN

BACKGROUND: Cancer stem cells always express high levels of stemness-associated transcription factors to maintain their features. However, the regulatory mechanism of the stemness of cancer stem cells mediated by transcription factors has not been extensively explored. METHODS: The YB-1 gene in cancer stem cells was knocked out by the CRISPR/Cas9 system. The YB-1 knockout cancer stem cells were transfected with a vector expressing YB-1 to rescue YB-1, and then the cell proliferation, cell cycle, apoptosis, and stemness, as well as tumorigenesis in nude mice, were assessed to examine the effect of YB-1 in cancer stem cells. The target genes of YB-1 were confirmed by CHIP-seq. The totipotency or pluripotency of differentiated cancer stem cells were detected by tumorsphere formation assay and quantitative real-time PCR. RESULTS: The deletion of YB-1 gene inhibited the proliferation of breast cancer stem cells and melanoma stem cells, leading to cell cycle arrest and apoptosis, and induced irreversible differentiation of cancer stem cells. The tumorigenicity ability of YB-1-deleted cancer stem cells was significantly reduced in vitro and in vivo. The results of ChIP-seq showed that YB-1 maintained the stemness of cancer stem cells by promoting the expressions of stemness-associated genes (FZD-1, p21, GLP-1, GINS1, and Notch2). Furthermore, simultaneous expressions of YB-1 and the other four (SOX2, POU3F2, OCT-4, and OLIG1) or five (SOX2, SALL2, OCT-4, POU3F2, and Bmi-1) transcription factors in YB-1 knockout cancer stem cells restored the stemness of YB-1 knockout cancer stem cells. CONCLUSIONS: Our study indicated that YB-1 was required for maintaining the stemness of cancer stem cells and reverting the differentiated tumor cells into cancer stem cells.


Asunto(s)
Diferenciación Celular , Células Madre Neoplásicas/metabolismo , Factores de Transcripción/metabolismo , Animales , Apoptosis , Sistemas CRISPR-Cas/genética , Puntos de Control del Ciclo Celular , Línea Celular Tumoral , Proliferación Celular , Femenino , Receptores Frizzled/genética , Receptores Frizzled/metabolismo , Péptido 1 Similar al Glucagón/genética , Péptido 1 Similar al Glucagón/metabolismo , Humanos , Ratones , Ratones Desnudos , Células Madre Neoplásicas/citología , ARN Guía de Kinetoplastida/metabolismo , Factores de Transcripción/deficiencia , Factores de Transcripción/genética
18.
Environ Pollut ; 252(Pt B): 1439-1447, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31265954

RESUMEN

Arsenic (As) and antimony (Sb) are considered as priority environmental pollutants and their accumulation in crop plants particularly in rice has posed a great health risk. This study endeavored to investigate As and Sb contents in paired soil-rice samples obtained from Xikuangshan, the world largest active Sb mining region, situated in China, and to investigate As speciation and location in rice grains. The soil and rice samples were analyzed by coupling the wet chemistry, laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), synchrotron-based micro X-ray fluorescence mapping (µ-XRF) and micro X-ray absorption near-edge structure (µ-XANES) spectroscopy. The results of field survey indicated that the paddy soil in the region was co-polluted by Sb (5.91-322.35 mg kg-1) and As (0.01-57.21 mg kg-1). Despite the higher Sb concentration in the soil, rice accumulated more As than Sb indicating the higher phytoavailability of As. Dimethylarsinic acid (DMA) was the predominant species (>60% on average) in the rice grains while the percentage of inorganic As species was 19%-63%. The µ-XRF mapping of the grain section revealed that the most of As was distributed and concentrated in rice husk, bran and embryo. Sb was distributed similarly to As but was not in the endosperm of rice grain based on LA-ICP-MS. The present results deepened our understanding of the As/Sb co-pollution and their association with the agricultural-product safety in the vicinity of Sb mining area.


Asunto(s)
Antimonio/análisis , Arsénico/análisis , Contaminación Ambiental/análisis , Oryza/química , Contaminantes del Suelo/análisis , China , Minería , Suelo/química , Espectroscopía de Absorción de Rayos X
19.
Aging Cell ; 18(5): e13001, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31287605

RESUMEN

Rho-associated coiled-coil kinase 1 (ROCK1) is proposed to be implicated in Aß suppression; however, the role for ROCK1 in amyloidogenic metabolism of amyloid precursor protein (APP) to produce Aß was unknown. In the present study, we showed that ROCK1 kinase activity and its APP binding were enhanced in AD brain, resulting in increased ß-secretase cleavage of APP. Furthermore, we firstly confirmed that APP served as a substrate for ROCK1 and its major phosphorylation site was located at Ser655. The increased level of APP Ser655 phosphorylation was observed in the brain of APP/PS1 mice and AD patients compared to controls. Moreover, blockade of APP Ser655 phosphorylation, or inhibition of ROCK1 activity with either shRNA knockdown or Y-27632, ameliorated amyloid pathology and improved learning and memory in APP/PS1 mice. These findings suggest that activated ROCK1 targets APP Ser655 phosphorylation, which promotes amyloid processing and pathology. Inhibition of ROCK1 could be a potential therapeutic approach for AD.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/química , Precursor de Proteína beta-Amiloide/metabolismo , Fosfoserina/metabolismo , Quinasas Asociadas a rho/metabolismo , Enfermedad de Alzheimer/tratamiento farmacológico , Amidas/farmacología , Péptidos beta-Amiloides/antagonistas & inhibidores , Animales , Células Cultivadas , Células HEK293 , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Fosforilación/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Piridinas/farmacología , ARN Interferente Pequeño/farmacología , Quinasas Asociadas a rho/antagonistas & inhibidores
20.
Environ Int ; 130: 104932, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31238266

RESUMEN

Birnessite owing to its negative surface charge and defective structure exhibits high sorption affinities for Cd(II). However, Mn(II) can not only compete for the sorption sites with Cd(II), but also react with structural Mn(IV) in birnessite to form Mn(III), and thus, affect Cd(II) immobilization by birnessite. Herein, we investigate effects of Mn(II) on Cd(II) retention and remobilization on two birnessite δ-MnO2 and Mn(III)-rich δ-MnO2 (denoted as HE-MnO2). At pH 5.5, Cd(II) sorption to birnessite was inhibited by Mn(II) addition. Mn(II) addition to δ-MnO2 led to Cd(II) migration from vacant sites to edge sites, forming double-corner sharing (DCS) complexes. Mn(II) introduction to δ-MnO2 led to less stable Cd(II) species formed on birnessite, indicating that Cd(II) was more firmly bound to vacant sites than edge sites of birnessite. Cd(II) formed double-edge sharing (DES) and DCS complexes on HE-MnO2. Mn(II) addition to HE-MnO2 increased the CdMn distance in DES complexes. The stability of adsorbed Cd(II) on HE-MnO2 was slightly elevated due to Mn(II) addition. At pH 7.5, Mn(II) had no effect on Cd(II) sorption and desorption amounts on birnessite. However, low concentration of Mn(II) added to δ-MnO2 induced partial migration of Cd(II) from vacant sites to edge sites while high concentration of Mn(II) added to birnessite led to the formation of amorphous Cd(II)-Mn(III) coprecipitate. These findings imply that aqueous Mn(II) is an important factor in influencing Cd(II) immobilization by birnessite in the environment.


Asunto(s)
Cadmio/química , Compuestos de Manganeso/química , Óxidos/química , Adsorción , Oxidación-Reducción
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