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1.
Int J Biol Macromol ; : 131736, 2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38653433

RESUMO

A novel cationic lipoic acid grafted low molecular weight chitosan (LCNE-LA) conjugate was constructed and further self-assembled into GSH-responsive cationic nanocarrier to achieve better antitumor effect by combining encapsulated chemotherapy and oxidative damage induced by ROS. The resultant LCNE-LA cationic micelle exhibited favorable physicochemical properties (low CMC, small size, positively zeta potential and good stability), excellent biosafety and desired redox sensitivity. Next, doxorubicin (Dox) was embedded into hydrophobic core to form stable Dox/LCNE-LA micelle that had superior loading capacity. The GSH-induced release behavior, cellular uptake ability, ROS generation and GSH consumption capacity and in vitro antitumor activity of Dox/LCNE-LA micelle were systematically evaluated. Consequently, Dox/LCNE-LA cationic micelle with positively charged could efficiently enter into cancer cell and redox-sensitive release Dox via disulfide-thiol exchange reaction, which usually expend abundant GSH and disrupt redox homeostasis. Studies further confirmed that Dox/LCNE-LA micelle could increase ROS and reduced GSH content which might cause oxidative damage to tumor cell. Antitumor activity indicated that Dox/LCNE-LA micelle achieved an excellent cancer-killing effect, which might be attributed to combination treatment of Dox and ROS induce oxidative damage. Overall, this research was expected to provide a platform for antitumor treatment by triggering Dox release and promoting ROS generation.

2.
Org Lett ; 26(15): 3310-3315, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38587335

RESUMO

A catalyst system consisting of a chiral phosphoramidite ligand and Pd2(dba)3·CHCl3 causes the decarboxylation of 5-vinyloxazolidine-2,4-diones to generate amide-containing aza-π-allylpalladium 1,3-dipole intermediates, which are capable of triggering the dearomatization of 3-nitroindoles for diastereo- and enantioselective [3+2] cycloaddition, leading to the formation of a series of highly functionalized pyrroloindolines containing three contiguous stereogenic centers with excellent results (up to 99% yield, 88:12 dr, and 96% ee).

3.
Front Plant Sci ; 15: 1331443, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38533399

RESUMO

Plants interact with complex microbial communities in which microorganisms play different roles in plant development and health. While certain microorganisms may cause disease, others promote nutrient uptake and resistance to stresses through a variety of mechanisms. Developing plant protection measures requires a deeper comprehension of the factors that influence multitrophic interactions and the organization of phyllospheric communities. High-throughput sequencing was used in this work to investigate the effects of climate variables and bacterial wildfire disease on the bacterial community's composition and assembly in the phyllosphere of tobacco (Nicotiana tabacum L.). The samples from June (M1), July (M2), August (M3), and September (M4) formed statistically separate clusters. The assembly of the whole bacterial population was mostly influenced by stochastic processes. PICRUSt2 predictions revealed genes enriched in the M3, a period when the plant wildfire disease index reached climax, were associated with the development of the wildfire disease (secretion of virulence factor), the enhanced metabolic capacity and environmental adaption. The M3 and M4 microbial communities have more intricate molecular ecological networks (MENs), bursting with interconnections within a densely networked bacterial population. The relative abundances of plant-beneficial and antagonistic microbes Clostridiales, Bacillales, Lactobacillales, and Sphingobacteriales, showed significant decrease in severally diseased sample (M3) compared to the pre-diseased samples (M1/M2). Following the results of MENs, we further test if the correlating bacterial pairs within the MEN have the possibility to share functional genes and we have unraveled 139 entries of such horizontal gene transfer (HGT) events, highlighting the significance of HGT in shaping the adaptive traits of plant-associated bacteria across the MENs, particularly in relation to host colonization and pathogenicity.

4.
Org Lett ; 26(13): 2623-2628, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38522081

RESUMO

An efficient dearomative cyclization of 2-nitrobenzofurans via a thiol-triggered tandem Michael addition/intramolecular Henry reaction has been developed. A range of thiochromeno[3,2-b]benzofuran-11-ols and tetrahydrothieno[3,2-b]benzofuran-3-ols could be obtained in up to 99% yield and up to >20:1 dr. The valuable thiochromone fused benzofurans could be prepared with the reaction of 2-nitrobenzofurans and 2-mercaptobenzaldehyde via the tandem dearomative Michael addition/intramolecular Henry reaction/rearomatization/oxidative dehydrogenation process in a one-pot two-step operation. A mechanism for the reaction was tentatively proposed.

5.
ACS Appl Mater Interfaces ; 16(14): 17377-17392, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38551391

RESUMO

Quinolone residues resulting from body metabolism and waste discharge pose a significant threat to the ecological environment and to human health. Therefore, it is essential to monitor quinolone residues in the environment. Herein, an efficient and sensitive matrix-assisted laser desorption/ionization mass spectrometry (MALDI/MS) method was devised by using a novel molecularly imprinted heterojunction (MIP-TNs@GCNs) as the matrix. Molecularly imprinted titanium dioxide nanosheets (MIP-TNs) and graphene-like carbon nitrides (GCNs) were associated at the heterojunction interface, allowing for the specific, rapid, and high-throughput ionization of quinolones. The mechanism of MIP-TNs@GCNs was clarified using their adsorption properties and laser desorption/ionization capability. The prepared oxygen-vacancy-rich MIP-TNs@GCNs heterojunction exhibited higher light absorption and ionization efficiencies than TNs and GCNs. The good linearity (in the quinolone concentration range of 0.5-50 pg/µL, R2 > 0.99), low limit of detection (0.1 pg/µL), good reproducibility (n = 8, relative standard deviation [RSD] < 15%), and high salt and protein resistance for quinolones in groundwater samples were achieved using the established MIP-TNs@GCNs-MALDI/MS method. Moreover, the spatial distributions of endogenous compounds (e.g., amino acids, organic acids, and flavonoids) and xenobiotic quinolones from Rhizoma Phragmitis and Rhizoma Nelumbinis were visualized using the MIP-TNs@GCNs film as the MALDI/MS imaging matrix. Because of its superior advantages, the MIP-TNs@GCNs-MALDI/MS method is promising for the analysis and imaging of quinolones and small molecules.


Assuntos
Quinolonas , Humanos , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Proteínas , Adsorção
6.
Environ Monit Assess ; 196(4): 361, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38472544

RESUMO

In this study, we collected 56 species of fishery organisms (including fish, crustaceans, cephalopods, gastropods, and bivalves) from four seasonal survey cruises at the Dachen fishery grounds. We measured the concentrations of seven heavy metals (Cd, Zn, Cu, Pb, Cr, As, and Hg) in these fisheries organisms. We determined their trophic levels using carbon and nitrogen stable isotope techniques. We analyzed the characteristics of heavy metal transfer in the food chain. The results showed significant differences in heavy metal concentrations among different species. Among all biological groups, bivalves and gastropods exhibited higher levels of heavy metal enrichment than other biological groups, while fish had the lowest levels of heavy metal enrichment. Heavy metals exhibited different patterns of nutritional transfer in the food chain. While Hg showed a biomagnification phenomenon in the food chain, it was not significant. Cd, Zn, Cu, Pb, Cr, and As exhibited a trend of biodilution with increasing nutritional levels, except for As, which showed no significant correlation with δ15N.


Assuntos
Gastrópodes , Mercúrio , Metais Pesados , Poluentes Químicos da Água , Animais , Cádmio , Caça , Chumbo , Monitoramento Ambiental , Poluentes Químicos da Água/análise , Metais Pesados/análise , Cadeia Alimentar , Isótopos de Nitrogênio , China , Músculos/química
7.
Cancer Cell Int ; 24(1): 92, 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38431620

RESUMO

BACKGROUND: Cholangiocarcinoma represents a malignant neoplasm originating from the hepatobiliary tree, with a subset of tumors developing inside the liver. Intrahepatic cholangiocarcinomas (ICC) commonly exhibit an asymptomatic presentation, rendering both diagnosis and treatment challenging. Cuproptosis, an emerging regulated cell death pathway induced by copper ions, has garnered attention recently. As cancer cells show altered copper metabolism and comparatively higher copper needs, cuproptosis may play a role in the development of ICC. However, studies investigating this possibility are currently lacking. METHODS: Single-cell and bulk RNA sequence data were analyzed, and correlations were established between the expression of cuproptosis-related molecules and ICC patient survival. Genes with predicting survival were used to create a CUPT score using Cox and LASSO regression and tumor mutation burden (TMB) analysis. The CIBERSORT software was employed to characterize immune cell infiltration within the tumors. Furthermore, immune infiltration prediction, biological function enrichment, and drug sensitivity analyses were conducted to explore the potential implications of the cuproptosis-related signature. The effects of silencing solute carrier family 39 member 4 gene (SLC39A4) expression using siRNA were investigated using assays measuring cell proliferation, colony formation, and cell migration. Key genes of cuproptosis were detected by western blotting. RESULTS: The developed CUPT score divided patients into high and low CUPT score groups. Those with a low score had significantly better prognosis and longer survival. In contrast, high CUPT scores were associated with worse clinical outcomes and significantly higher TMB. Comparisons of the two groups also indicated differences in the immune infiltrate present in the tumors. Finally, we were able to identify 95 drugs potentially affecting the cuproptosis pathway. Some of these might be effective in the treatment of ICC. The in vitro experiments revealed that suppressing the expression of SLC39A4 in ICC cell lines resulted in reduced cell proliferation, colony formation, and cell migration. It also led to an increase in cell death and the upregulation of key genes associated with cuproptosis, namely ferredoxin 1 (FDX1) and dihydrolipoyl transacetylase (DLAT). These findings strongly suggest that this cuproptosis-associated molecule may play a pivotal role in the development and metastasis of ICC. CONCLUSIONS: Changes in the expression of a cuproptosis-related gene signature can predict the clinical prognosis of ICC with considerable accuracy. This supports the notion that cuproptosis influences the diversity and complexity of the immune microenvironment, mutational landscape, and biological behavior of ICC. Understanding this pathway better may hold promise for the development of innovative strategies in the management of this disease.

8.
Microorganisms ; 12(3)2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38543490

RESUMO

Bacillus subtilis, a probiotic bacterium with engineering potential, is widely used for the expression of exogenous proteins. In this study, we utilized the integrative plasmid pDG364 to integrate the hemagglutinin-neuraminidase (HN) gene from Newcastle disease virus (NDV) into the genome of the B. subtilis 168 model strain. We successfully constructed a recombinant B. subtilis strain (designated B. subtilis RH) that displays a truncated HN antigen fragment on the surface of its spores and further evaluated its immunogenic effects in mice. Using ELISA, we quantified the levels of IgG in serum and secretory IgA (sIgA) in intestinal contents. The results revealed that the recombinant B. subtilis RH elicited robust specific mucosal and humoral immune responses in mice. Furthermore, B. subtilis RH demonstrated potential mucosal immune adjuvant properties by fostering the development of immune organs and augmenting the number of lymphocytes in the small intestinal villi. Additionally, the strain significantly upregulated the relative expression of inflammatory cytokines such as IL-1ß, IL-6, IL-10, TNF-α, and IFN-γ in the small intestinal mucosa. In conclusion, the B. subtilis RH strain developed in this study exhibits promising mucosal immunogenic effects. It holds potential as a candidate for an anti-NDV mucosal subunit vaccine and offers a novel preventive strategy for the poultry industry against this disease.

9.
Front Pharmacol ; 15: 1335785, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38444944

RESUMO

One-carbon metabolism is a universal metabolic process that mediates the transfer of one-carbon units for purine and thymidine synthesis. One-carbon metabolism has been found to be dysregulated in various cancer types due to its role in production of purine and pyrimidine nucleotides, epigenetic program, and redox homeostasis. One-carbon metabolism is composed a network of one-carbon metabolic enzymes. Disturbing the expression and enzymatic activity of these one-carbon metabolic enzymes could lead to fluctuations of metabolites in the tumor microenvironment. Serine hydroxymethyltransferases (SHMTs) and methylenetetrahydrofolate dehydrogenases (MTHFDs) are gradually recognized as important one-carbon metabolic enzymes for regulating tumor initiation and development, representing potential therapeutic targets for anti-tumor strategies. In the review, we primarily focused on the role of SHMTs and MTHFDs in cancer. Several inhibitors targeting MTHFDs and SHMTs have exert its potential to decrease tumor burden and inhibit tumor proliferation, highlighting the potential of targeting one-carbon metabolic enzymes for anti-cancer strategies.

10.
Molecules ; 29(5)2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38474676

RESUMO

An efficient dearomative (3 + 2) cycloaddition of para-quinamines and 2-nitrobenzofurans has been developed. This reaction proceeds smoothly under mild conditions and affords a series of benzofuro[3,2-b]indol-3-one derivatives in good to excellent yields (up to 98%) with perfect diastereoselectivities (all cases > 20:1 dr). The scale-up synthesis and versatile derivatizations demonstrate the potential synthetic application of the protocol. A plausible reaction mechanism is also proposed to account for the observed reaction process. This work represents the first instance of the N-triggered dearomative (3 + 2) cycloaddition of 2-nitrobenzofurans.

11.
FASEB J ; 38(5): e23530, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38466314

RESUMO

Brevibacillus laterosporus is a strain of probiotic bacteria that has been widely used in pest control, cash crop, and other production areas. However, few studies have been conducted on its use as a feed additive in animals. Therefore, the probiotic potential of B. laterosporus PBC01 was evaluated by characterizing hydrophobicity, auto-aggregation activity, bile salt and simulated gastrointestinal fluid tolerance, bienzymatic, and antibacterial activity. Antibiotic susceptibility, hemolysis assays, and supplemental feeding of mice were also performed to evaluate safety features. Our results showed that B. laterosporus PBC01 had moderate hydrophobicity, high auto-agglutination ability. Meanwhile, B. laterosporus PBC01 had good tolerance to bile salt and simulated gastrointestinal fluid. It had the ability to secrete protease, cellulase, and to inhibit various pathogens. In addition, B. laterosporus PBC01 was sensitive to many antibiotics, and did not produce hemolysin. In the safety assessment of mice, it did not cause any deaths, nor did it affect the cell components of blood, antioxidant capacity, and reproductive health. The study indicated the great probiotic characteristics and safety of B. laterosporus PBC01. This may provide a theoretical basis for the clinical application and development of probiotic-based feed additives.


Assuntos
Bacillus , Brevibacillus , Animais , Camundongos , Antibacterianos/farmacologia , Ácidos e Sais Biliares
12.
Mol Neurobiol ; 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38421470

RESUMO

Oxidative stress (OS) is the main cause of secondary damage following intracerebral hemorrhage (ICH). The polarity expression of aquaporin-4 (AQP4) has been shown to be important in maintaining the homeostasis of water transport and preventing post-injury brain edema in various neurological disorders. This study primarily aimed to investigate the effect of the oxygen free radical scavenger, edaravone, on AQP4 polarity expression in an ICH mouse model and determine whether it involves in AQP4 polarity expression via the OS/MMP9/ß-dystroglycan (ß-DG) pathway. The ICH mouse model was established by autologous blood injection into the basal nucleus. Edaravone or the specific inhibitor of matrix metalloproteinase 9 (MMP9), MMP9-IN-1, called MMP9-inh was administered 10 min after ICH via intraperitoneal injection. ELISA detection, neurobehavioral tests, dihydroethidium staining (DHE staining), intracisternal tracer infusion, hematoxylin and eosin (HE) staining, immunofluorescence staining, western blotting, Evans blue (EB) permeability assay, and brain water content test were performed. The results showed that OS was exacerbated, AQP4 polarity was lost, drainage function of brain fluids was damaged, brain injury was aggravated, expression of AQP4, MMP9, and GFAP increased, while the expression of ß-DG decreased after ICH. Edaravone reduced OS, restored brain drainage function, reduced brain injury, and downregulated the expression of AQP4, MMP9. Both edaravone and MMP9-inh alleviated brain edema, maintained blood-brain barrier (BBB) integrity, mitigated the loss of AQP4 polarity, downregulated GFAP expression, and upregulated ß-DG expression. The current study suggests that edaravone can maintain AQP4 polarity expression by inhibiting the OS /MMP9/ß-DG pathway after ICH.

13.
J Nanobiotechnology ; 22(1): 80, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38418972

RESUMO

The advancement of biomaterials with antimicrobial and wound healing properties continues to present challenges. Macrophages are recognized for their significant role in the repair of infection-related wounds. However, the interaction between biomaterials and macrophages remains complex and requires further investigation. In this research, we propose a new sequential immunomodulation method to enhance and expedite wound healing by leveraging the immune properties of bacteria-related wounds, utilizing a novel mixed hydrogel dressing. The hydrogel matrix is derived from porcine acellular dermal matrix (PADM) and is loaded with a new type of bioactive glass nanoparticles (MBG) doped with magnesium (Mg-MBG) and loaded with Curcumin (Cur). This hybrid hydrogel demonstrates controlled release of Cur, effectively eradicating bacterial infection in the early stage of wound infection, and the subsequent release of Mg ions (Mg2+) synergistically inhibits the activation of inflammation-related pathways (such as MAPK pathway, NF-κB pathway, TNF-α pathway, etc.), suppressing the inflammatory response caused by infection. Therefore, this innovative hydrogel can safely and effectively expedite wound healing during infection. Our design strategy explores novel immunomodulatory biomaterials, offering a fresh approach to tackle current clinical challenges associated with wound infection treatment.


Assuntos
Anti-Infecciosos , Curcumina , Infecção dos Ferimentos , Animais , Suínos , Hidrogéis/farmacologia , Cicatrização , Biomimética , Bandagens , Antibacterianos/uso terapêutico , Materiais Biocompatíveis , Imunoterapia , Infecção dos Ferimentos/tratamento farmacológico
14.
RSC Adv ; 14(10): 6642-6655, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38390505

RESUMO

The development of ischemic heart disease (IHD) involves a variety of pathophysiological responses, such as mitochondrial dysfunction. Many compounds with antioxidant activity isolated from natural products have been shown to have significant effects on the prevention and treatment of cardiovascular diseases. However, little is known about the palliative effects of 3-caffeoylquinic acid isomers isolated from Saxifraga tangutica (S. tangutica) on myocardial ischemia/reperfusion injury (MIRI). Three isomers of 3-caffeoylquinic acid were isolated from S. tangutica and identified as neochlorogenic acid (Fr2-4-1-1, 18.5 mg), chlorogenic acid (Fr2-5-1-1, 81.7 mg) and cryptochlorogenic acid (Fr2-5-2-1, 15.0 mg) using medium-pressure liquid chromatography-high-pressure two-dimensional liquid chromatography. An in vitro DPPH assay showed that cryptochlorogenic acid (CCGA), neochlorogenic acid (NCGA) and chlorogenic acid (CGA) (in order of activity from strongest to weakest) possessed superior antioxidant activity. Langendorff's in vitro model was utilized to explore the protective effects of 3 caffeoylquinic acid isomers against MIRI. The ex vivo MIRI assay demonstrated that CCGA significantly improved hemodynamic function (P < 0.05), hemodynamic function-related indices (LVDP, RPP, +dP/dt and -dP/dt), and cell morphology in I/R myocardium tissues. In addition, the results of western blot analysis showed that mitochondrial biogenesis was significantly increased in I/R myocardial tissues after treatment with CCGA. In contrast, the activities of CGA and NCGA were lower. This is the first demonstration of efficient preparative isolation of 3-caffeoylquinic acid isomers (CGA, NCGA and CCGA) from S. tangutica. CCGA may be a promising approach for the treatment of cardiac I/R injury, especially for the regulation of mitochondrial biogenesis after MIRI.

15.
Org Lett ; 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38385527

RESUMO

The first direct catalytic asymmetric Mannich reaction of 2-alkylazaarenes and ketimines was realized with a chiral Cu-bis(oxazoline) complex as the catalyst. The asymmetric addition of 2-alkylpyridines to isatin-derived ketimines proceeded smoothly to afford α,ß-functionalized 2-substituted pyridines bearing 3-amino-3,3-disubstituted oxindole motifs with excellent results (≤99% yield, 99:1 dr, and 98% ee). The catalytic system was also extended to 2-alkylbenzothiazoles as nucleophiles for the asymmetric Mannich reaction of ketimines.

16.
Org Lett ; 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38385803

RESUMO

This study demonstrates a highly efficient regiodivergent ligand-controlled palladium-catalyzed cycloaddition reaction of vinyloxazolidine-2,4-diones with 1,3,5-triazinanes. In the presence of a diphosphine ligand, the reaction proceeds via a (5+2) cycloaddition pathway to afford 1,3-diazepin-4-ones in excellent yields, while using a monophosphine ligand, the reaction proceeds smoothly via a (3+2) cycloaddition pathway to give imidazolidin-4-ones in good yields.

17.
Fitoterapia ; 174: 105837, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38286314

RESUMO

Mikania micrantha is a perennial liana of the genus Mikania of the Asteraceae family. It is a commonly used medicine in South America for treating fever, malaria, dysentery, snake bites, etc. Because of its strong adaptability and ability to inhibit the growth of its associated plants, Mikania micrantha is considered an invasive species in China and is known as a plant killer. Preliminary studies have shown that Mikania micrantha has an antipruritic effect, but the antipruritic active substance is not yet clear. In this study, a 4-aminopyridine-induced itching model in mice was used to determine the antipruritic effects of petroleum ether, ethyl acetate, ethanol extraction site, and Mikania micrantha volatile oil. GC-MS was used to analyze the components of the antipruritic fractions, combined with mice itch-causing models to study the antipruritic effects of ß-caryophyllene and humulene. The safety of ß-caryophyllene was preliminarily evaluated through the acute toxicity test of mice skin. The ethyl acetate and volatile oil of Mikania micrantha have apparent antipruritic effects. Humulene and ß-caryophyllene have a quantitative-effective relationship to inhibit itching in mice. The acute toxicity test of mouse skin showed that ß-caryophyllene has no acute toxicity. This study indicated that the main antipruritic active ingredients of Mikania micrantha are ß-caryophyllene and humulene.


Assuntos
Acetatos , Mikania , Sesquiterpenos Monocíclicos , Óleos Voláteis , Sesquiterpenos Policíclicos , Animais , Camundongos , Antipruriginosos/farmacologia , Estrutura Molecular , Óleos Voláteis/farmacologia , Prurido
18.
J Chromatogr A ; 1717: 464683, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38295741

RESUMO

The complex and cumbersome preparation of magnetic covalent organic frameworks (COFs) nanocomposites on a small scale limits their application. Herein, a rapid and easy route was employed for the preparation of magnetic thiourea-based COFs nanocomposites. COFs were coated on Fe3O4 nanoparticles at room temperature without a catalyst within approximately 30 min. This method is suitable for the large-scale preparation of magnetic adsorbent. Using the as-prepared magnetic adsorbent (Fe3O4@COF-TpTU), we developed a simple, efficient, and sensitive magnetic solid-phase extraction-high performance liquid chromatography-inductively coupled plasma-mass spectrometry (MSPE-HPLC-ICP-MS) for the enrichment and determination of mercury species, including Hg2+, methylmercury (MeHg), and ethylmercury (EtHg). The effects of the experimental parameters on the extraction efficiency, including solution pH, adsorption and desorption time, composition and volume of the elution solvent, salinity, coexisting ions, and dissolved organic matter, were comprehensively investigated. Under optimised conditions, the limits of detection in the developed method were 0.56, 0.34, and 0.47 ng L-1 with enrichment factors of 190, 195, and 180-fold for Hg2+, MeHg, and EtHg, respectively. The satisfactory spiked recoveries (97.0-103%) in real water samples and high consistency between the certified and determined values in a certified reference material demonstrate the high accuracy and reproducibility of the developed method. The as-proposed method with simple operation, high sensitivity, and excellent anti-matrix interference performance was successfully applied to the enrichment and determination of trace levels of mercury species in the natural samples with complicated matrices, such as underground water, surface water, seawater and biological samples.


Assuntos
Mercúrio , Estruturas Metalorgânicas , Compostos de Metilmercúrio , Mercúrio/análise , Estruturas Metalorgânicas/química , Cromatografia Líquida de Alta Pressão/métodos , Tioureia , Reprodutibilidade dos Testes , Temperatura , Compostos de Metilmercúrio/análise , Água/química , Fenômenos Magnéticos , Extração em Fase Sólida/métodos
19.
ACS Appl Mater Interfaces ; 16(3): 3451-3459, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38194627

RESUMO

As the demand for ethylene grows continuously in industry, conversion of ethane to ethylene has become more and more important; however, it still faces fundamental challenges of low ethane conversion, low ethylene selectivity, overoxidation, and instability of catalysts. Electrooxidative dehydrogenation of ethane (EODHE) in a solid oxide electrolysis cell (SOEC) is an alternative process. Here, a multiphase oxide Ce0.6Mn0.3Fe0.1O2-δ-NiFe-MnOx has been fabricated by a self-assembly process and utilized as the SOEC anode material for EODHE. The highest ethane conversions reached 52.23% with 94.11% ethylene selectivity at the anode side and CO with 10.9 mL min-1 cm-2 at the cathode side, at 1.8 V at 700 °C. The remarkable electrooxidative performance of CMF-NiFe-MnOx is ascribed to the NiFe alloy and MnOx nanoparticles and improvement of the concentration of oxygen vacancies within the fluorite substrate, generating dual active sites for C2H6 adsorption, dehydrogenation, and selective transformation of hydrogen without overoxidizing the ethylene generated. Such a tailored strategy achieves no significant degradation observed after 120 h of operation and constitutes a promising basis for EODHE.

20.
Circulation ; 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38223978

RESUMO

BACKGROUND: During the neonatal stage, the cardiomyocyte undergoes a constellation of molecular, cytoarchitectural, and functional changes known collectively as cardiomyocyte maturation to increase myocardial contractility and cardiac output. Despite the importance of cardiomyocyte maturation, the molecular mechanisms governing this critical process remain largely unexplored. METHODS: We leveraged an in vivo mosaic knockout system to characterize the role of Carm1, the founding member of protein arginine methyltransferase, in cardiomyocyte maturation. Using a battery of assays, including immunohistochemistry, immuno-electron microscopy imaging, and action potential recording, we assessed the effect of loss of Carm1 function on cardiomyocyte cell growth, myofibril expansion, T-tubule formation, and electrophysiological maturation. Genome-wide transcriptome profiling, H3R17me2a chromatin immunoprecipitation followed by sequencing, and assay for transposase-accessible chromatin with high-throughput sequencing were used to investigate the mechanisms by which CARM1 (coactivator-associated arginine methyltransferase 1) regulates cardiomyocyte maturation. Finally, we interrogated the human syntenic region to the H3R17me2a chromatin immunoprecipitation followed by sequencing peaks for single-nucleotide polymorphisms associated with human heart diseases. RESULTS: We report that mosaic ablation of Carm1 disrupts multiple aspects of cardiomyocyte maturation cell autonomously, leading to reduced cardiomyocyte size and sarcomere thickness, severe loss and disorganization of T tubules, and compromised electrophysiological maturation. Genomics study demonstrates that CARM1 directly activates genes that underlie cardiomyocyte cytoarchitectural and electrophysiological maturation. Moreover, our study reveals significant enrichment of human heart disease-associated single-nucleotide polymorphisms in the human genomic region syntenic to the H3R17me2a chromatin immunoprecipitation followed by sequencing peaks. CONCLUSIONS: This study establishes a critical and multifaceted role for CARM1 in regulating cardiomyocyte maturation and demonstrates that deregulation of CARM1-dependent cardiomyocyte maturation gene expression may contribute to human heart diseases.

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