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1.
J Environ Sci (China) ; 148: 174-187, 2025 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39095155

RESUMO

Cost-effective CO2 adsorbents are gaining increasing attention as viable solutions for mitigating climate change. In this study, composites were synthesized by electrochemically combining the post-gasification residue of Macadamia nut shell with copper benzene-1,3,5-tricarboxylate (CuBTC). Among the different composites synthesized, the ratio of 1:1 between biochar and CuBTC (B 1:1) demonstrated the highest CO2 adsorption capacity. Under controlled laboratory conditions (0°C, 1 bar, without the influence of ambient moisture or CO2 diffusion limitations), B 1:1 achieved a CO2 adsorption capacity of 9.8 mmol/g, while under industrial-like conditions (25°C, 1 bar, taking into account the impact of ambient moisture and CO2 diffusion limitations within a bed of adsorbent), it reached 6.2 mmol/g. These values surpassed those reported for various advanced CO2 adsorbents investigated in previous studies. The superior performance of the B 1:1 composite can be attributed to the optimization of the number of active sites, porosity, and the preservation of the full physical and chemical surface properties of both parent materials. Furthermore, the composite exhibited a notable CO2/N2 selectivity and improved stability under moisture conditions. These favorable characteristics make B 1:1 a promising candidate for industrial applications.


Assuntos
Dióxido de Carbono , Estruturas Metalorgânicas , Dióxido de Carbono/química , Adsorção , Estruturas Metalorgânicas/química , Poluentes Atmosféricos/química , Carvão Vegetal/química
2.
Environ Monit Assess ; 196(11): 1006, 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39358490

RESUMO

The present investigation evaluates three satellite precipitation products (SPPs), Multi-Source Weighted-Ensemble Precipitation (MSWEP), Global Precipitation Climatology Centre (GPCC), Climate Hazard Infrared Precipitation with Station Data (CHIRPS), and two reanalysis datasets, namely, the ERA5 atmosphere reanalysis dataset (ERA5) and Indian Monsoon Data Assimilation and Analysis (IMDAA), against the good quality gridded reference dataset (1991-2022) developed by the India Meteorological Department (IMD). The evaluation was carried out in terms of the rainfall detection ability and estimation accuracy of the products using metrics such as the false alarm ratio (FAR), probability of detection (POD), misses, root mean square error (RMSE), and percent bias (PBIAS). Among all the rainfall products, ERA5 had the best ability to capture rainfall events with a higher POD, followed by MSWEP. Both MSWEP and ERA5 had PODs of 70-100% in more than 90% of the grids and less than 35% of missing rainfall events in the entire Tamil Nadu. In the case of the rainfall estimation accuracy evaluation, the MSWEP exhibited superior performance, with lower RMSEs and biases ranging from - 25 to 25% at the annual and seasonal scales. In northeast monsoon (NEM), CHIRPS demonstrated a comparable performance to that of MSWEP in terms of the RMSE and PBIAS. These findings will help product users select the best reliable rainfall dataset for improved research, diversified applications in various sectors, and policy-making decisions.


Assuntos
Monitoramento Ambiental , Chuva , Índia , Monitoramento Ambiental/métodos , Imagens de Satélites , Estações do Ano , Clima , Análise Espaço-Temporal
3.
Bioorg Med Chem Lett ; 113: 129969, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39299490

RESUMO

While artemisinin and its derivatives, including 11-azaartemisinin-based compounds, have shown promising anticancer activity, the integration of halogens into aromatic structures can amplify drug potency, metabolic stability, and selectivity. Herein, we present the synthesis of new novel 11-azaartemisinin derivatives bearing halogenated aromatic moieties connected via 1,2,3-triazole bridges and evaluate their anticancer activities against three human tumor cell lines: epidermoid carcinoma (KB), hepatocellular carcinoma (HepG2), and human lung adenocarcinoma (A549). Among the synthesized compounds, six of them (8c-h) displayed good to excellent antiproliferative activity in the low micromolar range across all three human cancer cell lines. In general, the m-bromide (8c) and m-iodide (8d) compounds exhibited superior anticancer activities compared to their o- and p-analogs, as well as the m-chloride and m-fluoride compounds. The most promising m-Br compound (8c) displayed 50 % inhibition of KB, HepG2, and A549 cell growth at concentrations of 7.7, 42.5, and 15.5 µM, respectively. Notably, the m-Br compound (8c) exhibited approximately 32-, 6-, and 16-fold lower activity in normal cells (Hek293) compared to KB, HepG2, and A549 tumor cells, respectively, indicating a significant tumor-selectivity.

4.
Sci Robot ; 9(94): eado4553, 2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39321276

RESUMO

The heart's intricate myocardial architecture has been called the Gordian knot of anatomy, an impossible tangle of intricate muscle fibers. This complexity dictates equally complex cardiac motions that are difficult to mimic in physical systems. If these motions could be generated by a robotic system, then cardiac device testing, cardiovascular disease studies, and surgical procedure training could reduce their reliance on animal models, saving time, costs, and lives. This work introduces a bioinspired soft robotic left ventricle simulator capable of reproducing the minutiae of cardiac motion while providing physiological pressures. This device uses thin-filament artificial muscles to mimic the multilayered myocardial architecture. To demonstrate the device's ability to follow the cardiac motions observed in the literature, we used canine myocardial strain data as input signals that were subsequently applied to each artificial myocardial layer. The device's ability to reproduce physiological volume and pressure under healthy and heart failure conditions, as well as effective simulation of a cardiac support device, were experimentally demonstrated in a left-sided mock circulation loop. This work also has the potential to deliver faithful simulated cardiac motion for preclinical device and surgical procedure testing, with the potential to simulate patient-specific myocardial architecture and motion.


Assuntos
Materiais Biomiméticos , Ventrículos do Coração , Coração Auxiliar , Contração Miocárdica , Miocárdio , Robótica , Robótica/instrumentação
6.
Adv Sci (Weinh) ; : e2405610, 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39159303

RESUMO

Flexible robotic systems (FRSs) and wearable user interfaces (WUIs) have been widely used in medical fields, offering lower infection risk and shorter recovery, and supporting amiable human-machine interactions (HMIs). Recently, soft electric, thermal, magnetic, and fluidic actuators with enhanced safety and compliance have innovatively boosted the use of FRSs and WUIs across many sectors. Among them, soft hydraulic actuators offer great speed, low noise, and high force density. However, they currently require bulky electric motors/pumps, pistons, valves, rigid accessories, and complex controllers, which inherently result in high cost, low adaptation, and complex setups. This paper introduces a novel soft fibrous syringe architecture (SFSA) consisting of two or more hydraulically connected soft artificial muscles that enable electricity-free actuation, motorless control, and built-in sensing ability for use in FRSs and WUIs. Its capabilities are experimentally demonstrated with various robotic applications including teleoperated flexible catheters, cable-driven continuum robotic arms, and WUIs. In addition, its sensing abilities to detect passive and active touch, surface texture, and object stiffness are also proven. These excellent results demonstrate a high feasibility of using a current-free and motor-less control approach for the FRSs and WUIs, enabling new methods of sensing and actuation across the robotic field.

7.
J Hum Genet ; 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38982180

RESUMO

Age at diagnosis (AAD) of Type 1 diabetes (T1D) is determined by the age at onset of the autoimmune attack and by the rate of beta cell destruction that follows. Twin studies found that T1D AAD is strongly influenced by genetics, notably in young children. In young UK, Finnish, Sardinian patients AAD-associated genomic variants were previously identified, which may vary across populations and with time. In 1956 children of European ancestry born in mainland France in 1980-2008 who declared T1D before 15 years, we tested 94 T1D-associated SNPs for their association with AAD using nonparametric Kruskal-Wallis test. While high-risk HLA genotypes were not found to be associated with AAD, fourteen SNPs located in 12 non-HLA loci showed a strong association (2.9 × 10-12 < P < 1.4 × 10-3 after FDR correction). Four of these loci have been associated with AAD in previous cohorts (GSDMB, IL2, TNFAIP3, IL1), supporting a partially shared genetic influence on AAD of T1D in the studied European populations. In contrast, the association of 8 new loci CLEC16A, TYK2, ERBB3, CCR7, FCRL3, DNAH2, FGF3/4, and HPSE2 with AAD is novel. The 12 protein-coding genes located within these loci are involved in major immune pathways or in predisposition to other autoimmune diseases, which suggests a prominent role for these genes in the early immune mechanisms of beta cell destruction.

8.
BMC Cancer ; 24(1): 841, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39009994

RESUMO

PURPOSE: Standard oral cancer chemotherapy (OCT) or targeted therapy (OTT) has expanded the treatment methods for hepatocellular carcinoma (HCC). However, its principal nonadherence causes a reduction in efficacy. We aimed to evaluate the status of nonadherence and influencing factors among outpatient patients with HCC. PATIENTS AND METHODS: In 2021, a prospective observational study was conducted on 384 patients with either old or newly diagnosed HCC treated with OTT. Nonadherence to OCT was determined using the eight-item Morisky Medication Adherence Scale, with a score < 6 points. The patients were finished with a six-month follow-up investigation by questionnaires. RESULTS: 54,8% of HCC outpatients were nonadherent to OCT, with a mean Morisky score of 5.19. They dropped out of the treatment mainly because of drug side effects, such as fatigue (72.4%), hand-foot syndrome (42.7%), diarrhea (38.3%), nausea (25%), insomnia (24.7%), abdominal pain (12%), and anxiety about these adverse events (65.9%). Additionally, financial difficulties and low relative copayments were significantly correlated with the noncompliant treatment of patients (OR = 2.29, 95% CI = 1.32-3.98, P = 0.003; OR = 4.36, 95% CI = 0.95-19.93, P = 0.039, respectively). Moreover, inadequate individual information about the clinical course, the art of treatment, and medication usage instructions were suggestive barriers to adherence to treatment (OR = 1.96, 95% CI = 1.08-3.55, P = 0.024; OR = 1.86, 95% CI = 1.1-3.14, P = 0.02; OR = 2.34, 95% CI = 1.29-4.26, P = 0.004, respectively). Finally, a low level of trust in doctors was an essential factor in nonadherence (Mean of the Anderson Trust in Physician Scale scores counted 38.12 vs. 43.97, respectively for non-adherence vs. adherence, P = 0.00001). CONCLUSIONS: This study suggests a high rate of primary nonadherence to standard oral targeted therapy among HCC outpatient patients because of drug side effects, patient awareness of treatment, and lack of confidence in healthcare providers. Close supervision, proper medication instructions, appropriate dosage reductions, and comprehensive patient counseling might be necessary to control nonadherence.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Adesão à Medicação , Humanos , Masculino , Carcinoma Hepatocelular/tratamento farmacológico , Feminino , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/psicologia , Pessoa de Meia-Idade , Adesão à Medicação/estatística & dados numéricos , Idoso , Estudos Prospectivos , Vietnã/epidemiologia , Prevalência , Administração Oral , Inquéritos e Questionários , Antineoplásicos/uso terapêutico , Antineoplásicos/efeitos adversos , Adulto
9.
RSC Adv ; 14(26): 18330-18342, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38854829

RESUMO

This study aims to synthesize a guest-host complex derived from rutin (Rut) and ß-cyclodextrin (ß-CD) (denoted as [Rut⊂ß-CD]). The obtained substance was characterized by the FT-IR and DSC methods, signifying the formation of an inclusion complex between Rut and ß-CD. Complex formation increased the antioxidant activity of rutin corresponding to the decrease of EC50 values from 1.547 × 10-5 mol L-1 to 1.227 × 10-5 mol L-1 according to the DPPH free radical scavenging test. The rutin-ß-CD interaction energies were calculated in the vacuum and various solvents (e.g., water, ethanol, and dimethylsulfoxide) utilizing an accurate and broadly parametrized self-consistent tight-binding quantum chemical method (GFN2-xTB). The calculation results reveal the influence of solvent on the structural formation of the rutin-ß-CD complex. In both the vacuum and aqueous solution, rutin can enter into the small-sized empty cavity of ß-CD, albeit through different terminals, resulting in distinct preferential structures. The presence of organic solvents appears to reduce the interaction between rutin and ß-CD, with the interaction strength following the order: water > ethanol > dimethyl sulfoxide.

10.
J Chromatogr A ; 1730: 465116, 2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-38936163

RESUMO

This work explores strategies for electrokinetic preconcentration of extracellular vesicles (EVs) that are potential source of biomarkers for different diseases. The first approach that led to successful preconcentration of EVs is based on large volume sample stacking (LVSS), allowing an enrichment factor of 7 for CE of EVs with long-end injection (using a capillary with an effective length of 50 cm). Attempts were also made to perform multiple cycles of LVSS, field amplified sample stacking (FASS) and field amplified sample injection (FASI), to improve EVs preconcentration performance. The focus was then put on development of capillary isotachophoresis under high ionic strengths (IS) for electrokinetic enrichment of slow migrating EVs having heterogeneous mobilities. This approach relies on the use of extremely high concentrations of the terminating electrolyte (TE) to slow down the mobility of TE co-ions, rendering them slower than those of EVs. The limit of detection for intact EVs using the developed ITP-UV method reached 8.3 × 108 EVs/mL, allowing an enrichment of 25 folds and a linear calibration up to 4 × 1010 EVs/mL. The ITP-UV and ITP-LIF approaches were applied to provide the electrokinetic signature of EVs of bovine milk and human plasma as well as to visualize more specifically intravesicular fluorescently labelled EVs. The investigation of these strategies shredded light into the challenges still encountered with electrokinetic preconcentration and separation of heterogeneous EVs sub-populations which are discussed herein based on our results and other attempts reported in the literature.


Assuntos
Eletroforese Capilar , Vesículas Extracelulares , Isotacoforese , Leite , Vesículas Extracelulares/química , Eletroforese Capilar/métodos , Animais , Humanos , Bovinos , Leite/química , Isotacoforese/métodos , Limite de Detecção , Camundongos , Concentração Osmolar
11.
Ther Adv Gastrointest Endosc ; 17: 26317745241251713, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38745753

RESUMO

Objective: Endoscopic retrograde cholangiopancreatography (ERCP) in patients who have undergone Billroth II gastroenterostomy (B-II GE) has been challenging, requiring flexibility in technical approaches during execution. The study aims to assess the effectiveness of enhanced techniques in performing ERCP on this patient group in Vietnam. Method: A total of 42 Vietnamese patients with B-II GE performed an ERCP using a duodenoscope or a modification of ERCP equipment (a cap-fitted regular forward-viewing endoscope) if the former failed. The effectiveness and safety of the ERCP technique were assessed, particularly in patients who underwent the forward-viewing endoscope method. Result: A total of 39 out of 42 patients had the Vater's papilla identified, among whom 12 patients (30.8%) achieved successful cannulation into the bile duct using a side-viewing endoscope, significantly lower than the success rate using a forward-viewing endoscope (25/27, counted 92.6%, with p < 0.001). After successful cannulation, the rate of stone clearance, the procedural time, and the hospitalization duration of the patients were equivalent between the two methods and were not dependent on the number or size of the stones. On the other hand, post-ERCP complications in patients utilizing forward-viewing endoscopy included acute pancreatitis (22.2%), post-sphincterotomy bleeding (3.7%), septicemia (4.8%), and perforation (0%). These complications were mild and amenable to conservative endoscopic and medical management, and no mortality was observed. The rates of complications and adverse events after ERCP are comparable between the two treatment methods, even though the end-viewing endoscope is used after the failure of the side-viewing endoscope. Conclusion: Alter ERCP utilizing a cap-fitted forward-viewing endoscope can be a primary choice for treating common bile duct stones in patients with a Billroth II gastric resection history because of high efficacy and acceptable complications. It requires a high level of procedural expertise that requires multiple training sessions.


The promising change in the treatment approach for common bile duct stones in Vietnamese patients with a history of Billroth II gastrectomy Endoscopic retrograde cholangiopancreatography (ERCP) treating common bile duct stones in Vietnamese patients with a history of Billroth II gastrectomy is challenging due to changes in gastric anatomy and the limited visibility of the side-viewing endoscope. The researchers tried different techniques, including using a special type of forward-viewing endoscope with cap assistance. We found that using a forward-viewing endoscope was more successful in reaching certain areas compared to a side-viewing one. Although there were some complications, they were manageable, and the overall results were similar between the two methods. The study suggests that using a modified approach with a forward-viewing endoscope with cap assistance can be a good option for treating common bile duct stones in patients with a history of Billroth II gastric resection, but it requires skilled practitioners.

12.
Nanoscale ; 16(20): 9998-10010, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38699850

RESUMO

Identifying highly stable, cost-effective, platinum-free, and efficient electrocatalysts for the oxygen reduction reaction (ORR) remains a formidable challenge. The ORR is important for advancing fuel cell and zinc-air battery (ZAB) technologies towards cost-efficiency and environmental sustainability. This work presents the utilization of economically viable materials through a straightforward synthesis process, exhibiting the development of efficient Mo2C/Fe3C-NC catalysts ingeniously derived from phosphomolybdic acid (PMA) and iron phthalocyanine (FePc). The results demonstrate that the optimized Mo2C/Fe3C-NC3 catalysts exhibit remarkable electrochemical performance, evidenced by an impressive onset potential of ∼1.0 V versus RHE, a half-wave potential of 0.89 V, and a superior current density of about 6.2 mA cm-2. As for their performance in ZABs, the optimized catalysts reach a peak power density of 142 mW cm-2 at a current density of 200 mA cm-2. This synergy, coupled with the uniform distribution of Mo2C and Fe3C nanoparticles, greatly enhances the active catalytic sites and promotes electrolyte diffusion. Our approach diverges from traditional methods by employing an in situ self-assembled heterostructure of Mo2C/Fe3C on nitrogen-doped carbon tubes, avoiding the conventional high-temperature hydrogen gas reduction process. Beyond serving as feasible alternatives to commercially available Pt/C catalysts, these materials hold promise for large-scale production owing to their affordability and the simplicity of the synthesis technique. Such a breakthrough paves the way towards the realization of sustainable energy technologies and lays the groundwork for further exploration into amplifying the scalability and efficiency of ORR catalysts.

13.
Methods Mol Biol ; 2804: 117-125, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38753144

RESUMO

Several glycoproteins are validated biomarkers of various diseases such as cancer, cardiovascular diseases, chronic alcohol abuse, or congenital disorders of glycosylation (CDG). In particular, CDG represent a group of more than 150 inherited diseases with varied symptoms affecting multiple organs. The distribution of glycans from target glycoprotein(s) can be used to extract information to help the diagnosis and possibly differentiate subtypes of CDG. Indeed, depending on the glycans and the proteins to which they are attached, glycans can play a very broad range of roles in both physical and biological properties of glycoproteins. For glycans in general, capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) has become a staple. Analysis of glycans with CE-LIF requires several sample preparation steps, including release of glycans from the target glycoprotein, fluorescent labeling of glycans, and purification of labeled glycans. Here, we describe the protocol for glycan sample treatment in a microfluidic droplet system prior to CE-LIF of labeled glycans. The microfluidic droplet approach offers full automation, sample, and reagent volume reduction and elimination of contamination from external environment.


Assuntos
Biomarcadores , Eletroforese Capilar , Polissacarídeos , Eletroforese Capilar/métodos , Biomarcadores/análise , Polissacarídeos/análise , Humanos , Glicoproteínas/análise , Glicoproteínas/metabolismo , Microfluídica/métodos , Microfluídica/instrumentação , Glicosilação
14.
Chem Biodivers ; 21(7): e202400864, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38699953

RESUMO

Pinostrobin demonstrated anticancer properties, but its hydrophobic feature led to a reduction in bioavailability. The mitochondria-targeted approach successfully synthesized eight new alkyl triphenylphosphonium pinostrobin derivatives (1-8) with good yield in this study. Seven compounds (1-3, 5-8) showed greater cytotoxic potency against the human MCF-7 breast cancer cell line than pinostrobin. Molecular docking studies were performed with two important targets in hormone-dependent anticancer strategies, estrogen receptor α (ERα) ligand binding domains, 3ERT (antagonist recognition and antiproliferative function), and 1GWR (agonist recognition and pro-proliferative function). In addition, the MD simulation study of the two most potent compounds (2 and 3) complexed with both ERα forms suggested that compounds 2 and 3 could serve as favourable antagonists. Furthermore, the in silico ADMET prediction indicated that compounds 2 and 3 could be potential drug candidates.


Assuntos
Antineoplásicos , Neoplasias da Mama , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Simulação de Acoplamento Molecular , Compostos Organofosforados , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Proliferação de Células/efeitos dos fármacos , Compostos Organofosforados/química , Compostos Organofosforados/farmacologia , Compostos Organofosforados/síntese química , Relação Estrutura-Atividade , Células MCF-7 , Receptor alfa de Estrogênio/metabolismo , Receptor alfa de Estrogênio/antagonistas & inibidores , Feminino , Descoberta de Drogas , Estrutura Molecular , Relação Dose-Resposta a Droga , Flavanonas
15.
RSC Adv ; 14(17): 12081-12095, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38628478

RESUMO

Twelve compounds were isolated from Mussaenda saigonensis aerial parts through phytochemical analysis and the genus Mussaenda is the first place where the compounds 4-6 and 11-12 have been found. Based on the ability to inhibit NO production in RAW264.7 cells, compound 2 has demonstrated the strongest anti-inflammatory activity in vitro with an IC50 of 7.6 µM, as opposed to L-NMMA's IC50 of 41.3 µM. Compound 12 was found to be the most effective inhibitor of alpha-glucosidase enzyme in vitro, with an IC50 value of 42.4 µM (compared to 168 µM for acarbose). Compounds 1-12 were evaluated in vitro for antimicrobial activity using the paper dish method. Compound 11 demonstrated strong antifungal activity against M. gypseum with a MIC value of 50 µM. In silico docking for antimicrobial activity, pose 90 or compound 11 docked well to the 2VF5 enzyme, PDB, which explains why compound 11 had the highest activity in vitro. Entry 2/pose 280 demonstrated excellent anti-inflammatory activity in silico. The stability of the complex between pose 280 and the 4WCU enzyme for anti-inflammatory activity has been assessed using molecular dynamics over a simulation course ranging from 0 to 100 ns. It has been found to be stable from 60 and 100 ns. The Tyr 159 (95%, H-bond via water bridge), Asp 318 (200%, multiple contacts), Met 273 (75%, hydrophobic interaction via water bridge), and Gln 369 (75%, H-bond via water bridge) interacted well within the time range of 0 to 100 ns. It has more hydrophilic or polar pharmacokinetics.

16.
RSC Med Chem ; 15(3): 1046-1054, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38516598

RESUMO

Plants of the Zingiberaceae family, specifically those belonging to the Curcuma species, are commonly under consideration as potential therapeutic agents for the management of gastrointestinal diseases. In this study, we carried out a phytochemical study on Curcuma aromatica Salisb. (or so-called "Nghe trang" in Vietnamese) grown in Vietnam, which yields three newly discovered 3,5-diacetoxy diarylheptanoids (1-3) and six known 3,5-dihydroxyl diarylheptanoids (4-9). The bioactivity assessment shows that all isolated compounds, except compounds 3, 7, and 8, could inhibit urease. Compounds 4 and 9 significantly inhibit urease, with an IC50 value of 9.6 and 21.4 µM, respectively, more substantial than the positive control, hydroxyurea (IC50 = 77.4 µM). The structure-activity relationship (SAR) of linear diarylheptanoids was also established, suggesting that the hydroxyl groups at any position of skeleton diarylheptanoids are essential for exerting anti-urease action. Through a comparative analysis of the binding sites of hydroxyurea and diarylheptanoid compounds via our constructed in silico model, the mechanism of action of diarylheptanoid compounds is predicted to bind to the dynamic region close to the dinickel active center, resulting in a loss of catalytic activity. Such insights certainly help design and/or find diarylheptanoid-based compounds for treating gastric ulcers through inhibiting urease.

17.
Nanoscale Adv ; 6(7): 1822-1836, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38545284

RESUMO

This paper is devoted to reviewing a decade of the development of vacuum sputter deposition onto liquid poly(ethylene glycol) (PEG) to prepare metal and alloy nanoparticles (NPs) with a controlled particle growth, size, structure, and composition. Especially, we have discussed the fine structures of alloy NPs obtained in PEG and compared them with those sputtered onto other non-volatile liquids. Finally, we have shared our prospect of applications for the resulting alloy NPs.

18.
Small ; 20(27): e2400779, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38546187

RESUMO

The development of an efficient electrocatalyst for HMF oxidation to FDCA has been in the early stages. Herein, the NiNPs/GO-Ni-foam is fabricated as an electrocatalyst for FDCA production. However, the electrocatalytic performance of the untreated NiNPs/GO-Ni-foam is observed with moderate Faradaic efficiency (FE) (73.0%) and FDCA yield (80.2%). By electrochemically treating the NiNPs/GO-Ni-foam in an alkaline solution with positive potential at different treatment durations, the degree of NiOOH on metal surfaces is changed. The distinctive electrocatalytic activity obtained when using the different NiOOH degrees allows to understand the crucial impact of NiOOH species in HMF electrooxidation. Enhancing the portion of the NiOOH phase on the electrocatalyst surface improves electrocatalytic activity in terms of FE and FDCA yield up to 94.8±4.8% and 86.9±4.1%, respectively. Interestingly, as long as the NiOOH portion on the electrocatalyst surface is preserved or regenerated, the electrocatalyst performance can be intact even after several catalytic cycles. The theoretical study via density functional theory (DFT) also agrees with the experimental observations and confirms that the NiOOH phase facilitates the electrochemical transformation of HMF to FDCA through the HMFCA pathway, and the potential limiting step of the overall reaction is the oxidation of FFCA to FDCA.

19.
Enzyme Microb Technol ; 176: 110425, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38479200

RESUMO

Cytochrome P450s (CYPs) regulate plant growth and stress responses by producing diverse primary and secondary metabolites. However, the function of many plant CYPs remains unknown because, despite their structural similarity, predicting the enzymatic activity of CYPs is difficult. In this study, one member of the CYP736A subfamily (CYP736A61) from tomatoes was isolated and characterized its enzymatic functions. CYP736A61 was successfully expressed in Escherichia coli through co-expression with molecular chaperones. The purified CYP736A61 showed hydroxylation activity toward 7-ethoxycoumarin, producing 7-hydroxycoumarin or 3-hydroxy 7-ethoxycoumarin. Further substrate screening revealed that dihydrochalcone and stilbene derivates (resveratrol and polydatin) are the substrates of CYP736A61. CYP736A61 also mediated the hydroxylation of resveratrol and polydatin, albeit with low activity. Importantly, CYP736A61 mediated the cleavage of resveratrol and polydatin as well as pinostilbene and pterostilbene. Interestingly, CY736A61 also converted phloretin to naringenin chalcone. These results suggest that CYP736A61 is a novel CYP enzyme with stilbene cleavage activity.


Assuntos
Glucosídeos , Solanum lycopersicum , Estilbenos , Resveratrol , Estilbenos/química , Estilbenos/metabolismo , Catálise
20.
ACS Appl Mater Interfaces ; 16(9): 11537-11551, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38361372

RESUMO

The strategy of defect engineering is increasingly recognized for its pivotal role in modulating the electronic structure, thereby significantly improving the electrocatalytic performance of materials. In this study, we present defect-enriched nickel and iron oxides as highly active and cost-effective electrocatalysts, denoted as Ni0.6Fe2.4O4@NC, derived from NiFe-based metal-organic frameworks (MOFs) for oxygen reduction reactions (ORR) and oxygen evolution reactions (OER). XANES and EXAFS confirm that the crystals have a distorted structure and metal vacancies. The cation defect-rich Ni0.6Fe2.4O4@NC electrocatalyst exhibits exceptional ORR and OER activities (ΔE = 0.68 V). Mechanistic pathways of electrochemical reactions are studied by DFT calculations. Furthermore, a rechargeable zinc-air battery (RZAB) using the Ni0.6Fe2.4O4@NC catalyst demonstrates a peak power density of 187 mW cm-2 and remarkable long-term cycling stability. The flexible solid-state ZAB using the Ni0.6Fe2.4O4@NC catalyst exhibits a power density of 66 mW cm-2. The proposed structural design strategy allows for the rational design of electronic delocalization of cation defect-rich NiFe spinel ferrite attached to ultrathin N-doped graphitic carbon sheets in order to enhance active site availability and facilitate mass and electron transport.

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