Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.995
Filtrar
1.
Sci Rep ; 14(1): 12735, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38830972

RESUMO

In the present study, a new turbomolecular pump (TMP) performance prediction algorithm is proposed according to the variable surface combined blade row (VSCBR) geometric model. The simulation calculation program is designed to perform structural optimization and flow field analysis. Research on the pumping performance of the traditional straight blade row (TSBR) indicates that when the blade velocity ratio is greater than 1, the increase in the pumping speed and compression ratio of the TMP gradually tends to stabilize. Response surface methodology is used to optimize the structural parameters of the first four stages of the combined blade row. The optimized VSCBR increases the pumping speed by 18.2% compared to that of the TSBR. The flow field analysis based on the optimized VSCBR shows that gas molecules reaching the rear blades are likely to approach the outlet, and the proportion of gas molecules in this region exceeds 50%. Therefore, the blades we designed should be conducive to additional gas molecules reaching the outlet.

2.
Bioresour Technol ; : 130917, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38824969

RESUMO

Electro-fermentation (EF) was combined with anaerobic fermentation (AF) to promote medium-chain fatty acid (MCFA) from sewage sludge. Results showed that EF at acidification process significantly increased short-chain fatty acid (SCFA) production of by 0.5 times (82.4 mmol C/L). AF facilitated the chain elongation (CE) process by enhancing the SCFA conversion. Combined EF at acidification and AF at CE (EF-AF) achieved the highest MCFA production of 27.9 mmol C/L, which was 20 %-866 % higher than the other groups. Electrochemical analyses showed that enhanced SCFA and MCFA production was accompanied with good electrochemical performance at acidification and CE. Microbial analyses showed that EF-AF promoted MCFA production by enriching electrochemically active bacteria (EAB, Bacillus sp.). Enzyme analyses indicated that EF-AF promoted MCFA production by enriching the functional enzymes involved in Acetyl-CoA formation and the fatty acid biosynthesis (FAB) pathway. This study provided new insights into the production of MCFA from enhanced sewage sludge.

3.
Int J Cancer ; 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38822730

RESUMO

Nasopharyngeal carcinoma (NPC) risk prediction models based on Epstein-Barr virus (EBV)-antibody testing have shown potential for screening of NPC; however, the long-term stability is unclear. Here, we investigated the kinetics of two EBV-antibody NPC risk scores within the Taiwan NPC Multiplex Family Study. Among 545 participants with multiple blood samples, we evaluated the stability of a 2-marker enzyme-linked immunosorbent assay score and 13-marker multiplex serology score using the intra-class correlation coefficient (ICC) by fitting a linear mixed model that accounted for the clustering effect of multiple measurements per subject and age. We also estimated the clustering of positive tests using Fleiss's kappa statistic. Over an average 20-year follow-up, the 2-marker score showed high stability over time, whereas the 13-marker score was more variable (p < .05). Case-control status is associated with the kinetics of the antibody response, with higher ICCs among cases. Positive tests were more likely to cluster within the same individual for the 2-marker score than the 13-marker score (p < .05). The 2-marker score had an increase in specificity from ~90% for single measurement to ~96% with repeat testing. The 13-marker score had a specificity of ~73% for a single measurement that increased to ~92% with repeat testing. Among individuals who developed NPC, none experienced score reversion. Our findings suggest that repeated testing could improve the specificity of NPC screening in high-risk NPC multiplex families. Further studies are required to determine the impact on sensitivity, establish optimal screening intervals, and generalize these findings to general population settings in high-risk regions.

4.
Opt Lett ; 49(11): 3142-3145, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38824348

RESUMO

Near-infrared semiconductor lasers subject to optical feedback usually produce chaos with a broad bandwidth of a few GHz. However, the reported mid-infrared interband cascade lasers (ICLs) only show chaos with a limited bandwidth below 1 GHz. Here we show that an ICL with optical feedback is able to generate broadband chaos as well. The mid-infrared chaos exhibits a remarkable bandwidth of about 6 GHz, which is comparable to that of the near-infrared counterpart. In addition, the spectral coverage in the electrical domain reaches as high as 17.7 GHz. It is found that the chaos bandwidth generally broadens with increasing feedback ratio and/or increasing pump current of the laser, while it is insensitive to the feedback length.

5.
Food Chem ; 455: 139923, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38833855

RESUMO

This research aimed to develop a novel, effective, and stable delivery system based on zein (ZE), sodium caseinate (SC), and quaternary ammonium chitosan (HACC) for curcumin (CUR). The pH-driven self-assembly combined with electrostatic deposition methods were employed to construct CUR-loaded ZE-SC nanoparticles with HACC coating (ZE-SC@HACC). The optimized nanocomposite was prepared at ZE:SC:HACC:CUR mass ratios of 1:1:2:0.1, and it had encapsulation efficiency of 89.3%, average diameter of 218.2 nm, and ζ-potential of 40.7 mV. The assembly of composites and encapsulation of CUR were facilitated primarily by hydrophobic, hydrogen-bonding, and electrostatic interactions. Physicochemical stability analysis revealed that HACC coating dramatically enhanced ZE-SC nanoparticles' colloidal stability and CUR's resistance to chemical degradation. Additionally, antioxidant activity and simulated digestion results indicated that CUR-ZE-SC@HACC nanoparticles showed higher free radical scavenging capacity and bio-accessibility of CUR than CUR-ZE-SC nanoparticles and free CUR. Therefore, the ZE-SC@HACC nanocomposite is an effective and viable delivery system for CUR.

6.
J Am Chem Soc ; 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38832699

RESUMO

Although progress has been made in enantioselective hydroboration of di- and trisubstituted alkenes over the past decades, enantioselective hydroboration of tetrasubstituted alkenes with high diastereo- and enantioselectivities continues as an unmet challenge since the 1950s due to its extremely low reactivity and the difficulties to simultaneously control the regio- and stereoselectivity of a tetrasubstituted alkene. Here, we report highly regio-, diastereo-, and enantioselective catalytic hydroboration of diverse acyclic tetrasubstituted alkenes. The delicate interplay of an electron-rich rhodium complex and coordination-assistance forms a highly adaptive catalyst that effectively overcomes the low reactivity and controls the stereoselectivity. The generality of the catalyst system is exemplified by its efficacy across various tetrasubstituted alkenes with diverse steric and electronic properties.

7.
Dalton Trans ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38836742

RESUMO

Electrocatalytic reduction of biomass-derived furan compounds provides a green and sustainable approach to produce value-added fuels and chemicals. Despite the achievements in unimolecular transformation, C-C coupling which holds great promise to yield precursors for high-density fuels has not received extensive attention. Herein, we report a Cu2O-derived nanowire array material with switchable selectivity to electrocatalytic reduction of furfural depending on the electrolyte pH. Besides a high selectivity of 98.4% to furfuryl alcohol via hydrogenation at pH 9.5, the Cu2O-derived array structure also exhibits a high selectivity of 83.5% to hydrofuroin via C-C coupling at pH 14. Upon control experiments and detailed characterization of the electrodes, the array architecture is proposed to decrease the diffusion of ketyl radicals which are the key intermediates for C-C coupling. The confined diffusion results in a high local concentration of the radicals in the array and facilitates their collision for enhancing the formation of hydrofuroin.

8.
Ann Intensive Care ; 14(1): 74, 2024 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-38735891

RESUMO

BACKGROUND: Current data on post-discharge mortality and rehospitalization is still insufficient among in-hospital survivors of cardiogenic shock (CS), including acute myocardial infarction (AMI) and non-AMI survivors. METHODS: Patients with CS who survived after hospital discharge were selected from the Taiwan National Health Insurance Research Database. Each patient was followed up at 3-year intervals. Mortality and rehospitalization were analyzed using Kaplan-Meier curves and Cox regression models. RESULTS: There were 16,582 eligible patients. Of these, 42.4% and 57.6% were AMI-CS and non-AMI-CS survivors, respectively. The overall mortality and rehospitalization rates were considerably high, with reports of 7.0% and 22.1% at 30 days, 24.5% and 58.2% at 1 year, and 38.9% and 73.0% at 3 years, respectively, among in-hospital CS survivors. Cardiovascular (CV) problems caused approximately 40% mortality and 60% rehospitalization. Overall, the non-AMI-CS group had a higher mortality burden than the AMI-CS group owing to older age and a higher prevalence of comorbidities. In multivariable models, the non-AMI-CS group exhibited a lower risk of all-cause mortality (adjusted hazard ratio [aHR] 0.69, 95% confidence interval [CI] 0.60 to 0.78) and CV mortality (aHR 0.65, 95% CI 0.54 to 0.78) compared to the AMI-CS group. However, these risks diminished and even reversed after one year (aHR 1.13, 95% CI 1.03 to 1.25 for all-cause mortality; aHR 1.27, 95% CI 1.09 to 1.49 for CV mortality).This reversal was not observed in all-cause and CV rehospitalization. For rehospitalization, AMI-CS was associated with the risk of CV rehospitalization in the entire observation period (aHR:0.80, 95% CI:0.76-0.84). CONCLUSIONS: In-hospital AMI-CS survivors had an increased risk of CV rehospitalization and 30-day mortality, whereas those with non-AMI-CS had a greater mortality risk after 1-year follow-up.

9.
Materials (Basel) ; 17(9)2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38730876

RESUMO

Amorphous thin films can be applied to increase the anti-corrosion ability of critical components. Atomized FeCrNiMoCSiB powders were hot-pressed into a disc target for R. F. magnetron sputtering on a 316L substrate to upgrade its corrosion resistance. The XRD spectrum confirmed that the film deposited by R. F. magnetron sputtering was amorphous. The corrosion resistance of the amorphous film was evaluated in a 1 M HCl solution with potentiodynamic polarization tests, and the results were contrasted with those of a high-velocity oxy-fuel (HVOF) coating and 316L, IN 600, and C 276 alloys. The results indicated that the film hardness and elastic modulus, as measured using a nanoindenter, were 11.1 and 182 GPa, respectively. The principal stresses in two normal directions of the amorphous film were about 60 MPa and in tension. The corrosion resistance of the amorphous film was much greater than that of the other samples, which showed a broad passivation region, even in a 1 M HCl solution. Although the amorphous film showed high corrosion resistance, the original pinholes in the film were weak sites to initiate corrosion pits. After polarization tests, large, deep trenches were seen in the corroded 316L substrate; numerous fine patches in the IN 600 alloy and grain boundary corrosion in the C276 alloy were observed.

10.
Small ; : e2401965, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38739099

RESUMO

Selective separation of ethylene and ethane (C2H4/C2H6) is a formidable challenge due to their close molecular size and boiling point. Compared to industry-used cryogenic distillation, adsorption separation would offer a more energy-efficient solution when an efficient adsorbent is available. Herein, a class of C2H4/C2H6 separation adsorbents, doped carbon molecular sieves (d-CMSs) is reported which are prepared from the polymerization and subsequent carbonization of resorcinol, m-phenylenediamine, and formaldehyde in ethanol solution. The study demonstrated that the polymer precursor themselves can be a versatile platform for modifying the pore structure and surface functional groups of their derived d-CMSs. The high proportion of pores centered at 3.5 Å in d-CMSs contributes significantly to achieving a superior kinetic selectivity of 205 for C2H4/C2H6 separation. The generated pyrrolic-N and pyridinic-N functional sites in d-CMSs contribute to a remarkable elevation of Henry selectivity to 135 due to the enhancement of the surface polarity in d-CMSs. By balancing the synergistic effects of kinetics and thermodynamics, d-CMSs achieve efficient separation of C2H4/C2H6. Polymer-grade C2H4 of 99.71% purity can be achieved with 75% recovery using the devised d-CMSs as reflected in a two-bed vacuum swing adsorption simulation.

11.
Bioact Mater ; 39: 74-105, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38783927

RESUMO

Mg is a typical biodegradable metal widely used for biomedical applications due to its considerable mechanical properties and bioactivity. Biodegradable polymers have attracted great interest owing to their favorable processability and inclusiveness. However, it is challenging for the degradation rates of Mg or polymers to precisely match tissue repair processes, and the significant changes in local pH during degradation hinder tissue repair. The concept of combining Mg with polymers is proposed to overcome the shortcomings of materials, aiming to meet repair needs from various aspects such as mechanics and biology. Therefore, it is essential to systematically understand the behavior of biodegradable Mg/polymer composite (BMPC) from the design, manufacturing, mechanical properties, degradation, and biological effects. In this review, we elaborate on the design concepts and manufacturing strategies of high-strength BMPC, the "structure-function" relationship between the microstructures and mechanical properties of composites, the variation in the degradation rate due to endogenous and exogenous factors, and the establishment of advanced degradation research platform. Additionally, the interplay among composite components during degradation and the biological function of composites under non-responsive/stimuli-responsive platforms are also discussed. Finally, we hope that this review will benefit future clinical applications of "structure-function" integrated biomaterials.

12.
Insect Sci ; 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38783625

RESUMO

Vitellogenin receptor (VgR) plays a crucial role in oogenesis by mediating endocytosis of vitellogenin and a portion of the yolk proteins in many insect species. However, the function of VgR in minute parasitoid wasps is largely unknown. Here, we applied Trichogramma dendrolimi, a minute egg parasitoid, as a study model to investigate the function of VgR in parasitoids. We developed RNA interference (RNAi) methods based on microinjection of prepupae in T. dendrolimi. RNAi employs nanomaterial branched amphipathic peptide capsules (BAPC) as a carrier for double-stranded RNA (dsRNA), significantly enhancing delivery efficiency. Also, artificial hosts without medium were used to culture the injected prepupae in vitro. Utilizing these methods, we found that ovarian growth was disrupted after knockdown of TdVgR, as manifested by the suppressed development of the ovariole and the inhibition of nurse cell internalization by oocytes. Also, the initial mature egg load in the ovary was significantly reduced. Notably, the parasitic capacity of the female adult with ovarian dysplasia was significantly decreased, possibly resulting from the low availability of mature eggs. Moreover, ovarian dysplasia in T. dendrolimi caused by VgR deficiency are conserved despite feeding on different hosts. The results confirmed a critical role of TdVgR in the reproductive ability of T. dendrolimi and provided a reference for gene functional studies in minute insects.

13.
Food Chem ; 451: 139461, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38701733

RESUMO

Copper as a widely applied element in food supply chain can cause serious contamination issues that threats food safety. In this research, we present a quick and visible method for trace copper ion (Cu2+) quantification in practical food samples. Polymer dots (Pdots) were firstly conjugated with a copper-specific DNA aptamer and then tailored with rhodamine B (RhB) to extinguish the electrochemiluminescence (ECL) signal through a resonance energy transfer process. The selective release of RhB leads to signal restoration when exposed to trace Cu2+ levels, achieving remarkable linearity with the logarithm of Cu2+ concentration within the range of 1 ng/L to 10 µg/L with an impressively low limit of detection at 11.8 pg/L. Most notably, our device was also applicable on visualizing and quantifying trace Cu2+ (∼0.2 µg/g) in practical Glycyrrhiza uralensis Fisch. samples, underscoring its potential as a tool for the early prevention of potential copper contamination in food samples.


Assuntos
Cobre , Técnicas Eletroquímicas , Contaminação de Alimentos , Medições Luminescentes , Cobre/análise , Cobre/química , Contaminação de Alimentos/análise , Medições Luminescentes/instrumentação , Medições Luminescentes/métodos , Técnicas Eletroquímicas/instrumentação , Limite de Detecção , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Análise de Alimentos/métodos , Aptâmeros de Nucleotídeos/química , Pontos Quânticos/química
14.
Eur J Med Res ; 29(1): 286, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38745338

RESUMO

BACKGROUND: Our study aimed to confirm a simplified radiological scoring system, derived from a modified Reiff score, to evaluate its relationship with clinical symptoms and predictive outcomes in Taiwanese patients with noncystic fibrosis bronchiectasis (NCFB). METHODS: This extensive multicenter retrospective study, performed in Taiwan, concentrated on patients diagnosed with NCFB verified through high-resolution computed tomography (HRCT) scans. We not only compared the clinical features of various types of bronchiectasis (cylindrical, varicose, and cystic). Furthermore, we established relationships between the severity of clinical factors, including symptom scores, pulmonary function, pseudomonas aeruginosa colonization, exacerbation and admission rates, and HRCT parameters using modified Reiff scores. RESULTS: Data from 2,753 patients were classified based on HRCT patterns (cylindrical, varicose, and cystic) and severity, assessed by modified Reiff scores (mild, moderate, and severe). With increasing HRCT severity, a significant correlation was found with decreased forced expiratory volume in the first second (FEV1) (p < 0.001), heightened clinical symptoms (p < 0.001), elevated pathogen colonization (pseudomonas aeruginosa) (p < 0.001), and an increased annual hospitalization rate (p < 0.001). In the following multivariate analysis, elderly age, pseudomonas aeruginosa pneumonia, and hospitalizations per year emerged as the only independent predictors of mortality. CONCLUSION: Based on our large cohort study, the simplified CT scoring system (Reiff score) can serve as a useful adjunct to clinical factors in predicting disease severity and prognosis among Taiwanese patients with NCFB.


Assuntos
Bronquiectasia , Índice de Gravidade de Doença , Humanos , Masculino , Feminino , Bronquiectasia/fisiopatologia , Bronquiectasia/diagnóstico por imagem , Taiwan/epidemiologia , Pessoa de Meia-Idade , Prognóstico , Idoso , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos , Volume Expiratório Forçado , Adulto , Pseudomonas aeruginosa/isolamento & purificação
15.
DNA Res ; 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38807352

RESUMO

Leuciscus merzbacheri is a native fish species found exclusively in the Junggar Basin in Xinjiang. It exhibits remarkable adaptability, thriving in varying water conditions such as the saline waters, the semi-saline water, and the freshwater. Despite its significantly economic and ecological value, the underlying mechanisms of its remarkable salinity tolerance remain elusive. Our study marks the first time the full-length transcriptome of L. merzbacheri has been reported, utilizing RNA-Seq and PacBio Iso-Seq technologies. We found that the average length of the full-length transcriptome is 1,780 bp, with an N50 length of 2,358 bp. We collected RNA-Seq data from gill, liver, and kidney tissues of L. merzbacheri from both saline water and freshwater environments, and conducted comparative analyses across these tissues. Further analysis revealed significant enrichment in several key functional gene categories and signaling pathways related to stress response and environmental adaptation. The findings provide a valuable genetic resource for further investigation into saline-responsive candidate genes, which will deepen our understanding of teleost adaptation to extreme environmental stress. This knowledge is crucial for the future breeding and conservation of native fish species.

16.
Front Biosci (Landmark Ed) ; 29(5): 201, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38812314

RESUMO

BACKGROUND: Ibrutinib could increase the risk of atrial fibrillation (AF) in chronic lymphocytic leukemia (CLL) patients. However, the precise mechanism underlying ibrutinib-induced AF remains incompletely elucidated. METHODS: We investigated the proportion of ibrutinib-treated CLL patients with new-onset AF. Optical mapping was conducted to reveal the proarrhythmic effect of ibrutinib on HL-1 cells. Fluorescence staining and western blot were used to compare connexins 43 and 40 expression in ibrutinib-treated and control groups. To identify autophagy phenotypes, we used western blot to detect autophagy-related proteins, transmission electron microscopy to picture autophagosomes, and transfected mCherry-GFP-LC3 virus to label autophagosomes and lysosomes. Hydroxychloroquine as an autophagy inhibitor was administered to rescue ibrutinib-induced Cx43 and Cx40 degradation. RESULTS: About 2.67% of patients developed atrial arrhythmias after ibrutinib administration. HL-1 cells treated with ibrutinib exhibited diminished conduction velocity and a higher incidence of reentry-like arrhythmias compared to controls. Cx43 and Cx40 expression reduced along with autophagy markers increased in HL-1 cells treated with ibrutinib. Inhibiting autophagy upregulated Cx43 and Cx40. CONCLUSIONS: The off-target effect of ibrutinib on the PI3K-AKT-mTOR signaling pathway caused connexin degradation and atrial arrhythmia via promoting autophagy. CLINICAL TRIAL REGISTRATION: ChiCTR2100046062, https://clin.larvol.com/trial-detail/ChiCTR2100046062.


Assuntos
Adenina , Fibrilação Atrial , Autofagia , Conexina 43 , Conexinas , Fosfatidilinositol 3-Quinases , Piperidinas , Proteínas Proto-Oncogênicas c-akt , Transdução de Sinais , Serina-Treonina Quinases TOR , Humanos , Adenina/análogos & derivados , Adenina/farmacologia , Adenina/efeitos adversos , Serina-Treonina Quinases TOR/metabolismo , Autofagia/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Piperidinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Conexina 43/metabolismo , Conexina 43/genética , Feminino , Fibrilação Atrial/metabolismo , Fibrilação Atrial/induzido quimicamente , Conexinas/metabolismo , Conexinas/genética , Masculino , Idoso , Pessoa de Meia-Idade , Proteína alfa-5 de Junções Comunicantes , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/induzido quimicamente
17.
Front Immunol ; 15: 1361531, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38698849

RESUMO

The whole-genome sequence of an African swine fever virus (ASFV) strain (HuB/HH/2019) isolated from Hubei, China, was highly similar to that of the Georgia 2007/1 strain ASFV. After infection with strong strains, domestic pigs show typical symptoms of infection, including fever, depression, reddening of the skin, hemorrhagic swelling of various tissues, and dysfunction. The earliest detoxification occurred in pharyngeal swabs at 4 days post-infection. The viral load in the blood was extremely high, and ASFV was detected in multiple tissues, with the highest viral loads in the spleen and lungs. An imbalance between pro- and anti-inflammatory factors in the serum leads to an excessive inflammatory response in the body. Immune factor expression is suppressed without effectively eliciting an immune defense. Antibodies against p30 were not detected in acutely dead domestic pigs. Sequencing of the peripheral blood mononuclear cell transcriptome revealed elevated transcription of genes associated with immunity, defense, and stress. The massive reduction in lymphocyte counts in the blood collapses the body's immune system. An excessive inflammatory response with a massive reduction in the lymphocyte count may be an important cause of mortality in domestic pigs. These two reasons have inspired researchers to reduce excessive inflammatory responses and stimulate effective immune responses for future vaccine development.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Animais , Suínos , Febre Suína Africana/virologia , Febre Suína Africana/imunologia , Vírus da Febre Suína Africana/imunologia , Vírus da Febre Suína Africana/genética , Citocinas , Linfócitos/imunologia , Linfócitos/metabolismo , Genótipo , Carga Viral , Sus scrofa , Contagem de Linfócitos
18.
Angew Chem Int Ed Engl ; : e202405650, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38695268

RESUMO

Microenvironment regulation of M-N4 single-atom catalysts (SACs) is a promising way to tune their catalytic properties toward the electrochemical CO2 reduction reaction. However, strategies that can effectively introduce functional groups around the M-N4 sites through strong covalent bonding and under mild reaction conditions are highly desired. Taking the hydrophilic Ni-N4 SAC as a representative, we report herein a [2+1] cycloaddition reaction between Ni-N4 and in-situ generated difluorocarbene (F2C:), and enable the surface fluorocarbonation of Ni-N4, resulting in the formation of a super-hydrophobic Ni-N4-CF2 catalyst. Meanwhile, the mild reaction conditions allow Ni-N4-CF2 to inherit both the electronic and structural configuration of the Ni-N4 sites from Ni-N4. Enhanced electrochemical CO2-to-CO Faradaic efficiency above 98% is achieved in a wide operating potential window from -0.7 V to -1.3 V over Ni-N4-CF2. In-situ spectroelectrochemical studies reveal that a highly hydrophobic microenvironment formed by the -CF2- group repels asymmetric H-bonded water at the electrified interface, inhibiting the hydrogen evolution reaction and promoting CO production. This work highlights the advantages of [2+1] cycloaddition reactions on the covalent modification of N-doped carbon-supported catalysts.

19.
Chem Biodivers ; : e202400900, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38713316

RESUMO

A new compound xylarkarynone A (1), a first reported natural product compound xylarkarynone B (2) and eight known compounds (3-10) were isolated from Xylaria sp. HHY-2. Their structures were elucidated by spectroscopic methods, DP4+ probability analyses and electronic circular dichroism (ECD) calculations. The bioactivities of isolated compounds were assayed. Compound 1 exhibited obvious activity against A549 cells with an IC50 value of 6.12 ± 0.28 µM. Additionally, compound 1 showed moderate antifungal activities against Plectosphaerella cucumerina and Aspergillus niger with minimum inhibitory concentrations (MICs) of both 16 µg/mL, which was at the same grade with positive control nystatin. Most compounds exhibited varying degrees of inhibitory activity against P. cucumerina, indicating that Xylaria sp. has potential as inhibitors against P. cucumerina.

20.
Pediatr Obes ; : e13127, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38747282

RESUMO

BACKGROUND: Lifestyle factors play an important role in the development and management of childhood obesity and its related cardiometabolic complications. OBJECTIVE/METHODS: We aimed to explore childhood obesity subtypes based on lifestyle factors and examine their association with cardiometabolic health. We included 1550 children with obesity from the National Health and Nutrition Examination Survey. Cluster analysis identified obesity subtypes based on four lifestyle factors (physical activity, diet quality, sedentary time and smoking). Multiple linear regression assessed their association with cardiometabolic factors. RESULTS: Five subtypes of childhood obesity were identified: unhealthy subtype (n = 571; 36.8%), physically active subtype (n = 185; 21.1%), healthy diet subtype (n = 404; 26.1%), smoking subtype (n = 125; 8.1%) and non-sedentary subtype (n = 265; 17.1%). Compared with the unhealthy subtype, the physically active subtype had lower insulin and HOMA-IR levels, and smoking subtype was associated with lower HDL levels. When compared with children with normal weight, all obesity subtypes had worse cardiometabolic profile, except the physically active subtype who had similar DBP, HbA1c and TC levels; smoking subtype who had similar TC levels; and healthy diet and non-sedentary subtypes who had similar DBP levels. CONCLUSION: Children of different lifestyle-based obesity subtypes might have different cardiometabolic risks. Our new classification system might help personalize assessment of childhood obesity.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...