Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 3.398
Filtrer
1.
Biodes Res ; 6: 0050, 2024.
Article de Anglais | MEDLINE | ID: mdl-39381623

RÉSUMÉ

Collagenases, a class of enzymes that are specifically responsible for collagen degradation, have garnered substantial attention because of their pivotal roles in tissue repair, remodeling, and medical interventions. This comprehensive review investigates the diversity, structures, and mechanisms of collagenases and highlights their therapeutic potential. First, it provides an overview of the biochemical properties of collagen and highlights its importance in extracellular matrix function. Subsequently, it meticulously analyzes the sources of collagenases and their applications in tissue engineering and food processing. Notably, this review emphasizes the predominant role played by microbial collagenases in commercial settings while discussing their production and screening methods. Furthermore, this study elucidates the methodology employed for determining collagenase activity and underscores the importance of an accurate evaluation for both research purposes and clinical applications. Finally, this review highlights the future research prospects for collagenases, with a particular focus on promoting wound healing and treating scar tissue formation and fibrotic diseases.

2.
Int J Biol Macromol ; 279(Pt 4): 135570, 2024 Nov.
Article de Anglais | MEDLINE | ID: mdl-39270908

RÉSUMÉ

Excessive UVB exposure increased the production of reactive oxygen species (ROS), leading to oxidative damage and epidermal inflammation. To enhance UVB protection effect, a strong phenolic antioxidant, ferulic acid (FA) was designed onto HA via a free radical mediated method. Our previous work has confirmed its structural characterization and in vitro antioxidant. The aim of this study was to evaluate its protective effects against UVB-induced damage in human HaCaT cells. We observed a significant reduction in cell viability to 57.43 % following UVB exposure at a dose of 80 mJ/cm2. However, pretreatment with FA-HA (250 to 2000 µg·mL-1) significantly attenuated cytotoxicity in a dose-dependent manner. Furthermore, FA-HA was found to suppress the intracellular generation of ROS and up-regulated the expression of the antioxidant enzyme superoxide dismutase (SOD). The elevated levels of pro-inflammatory cytokines, including interleukin-1 beta (IL-1ß), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α) as well as the mRNA expression of matrix metalloproteinase-1/9 (MMP-1/9) induced by UVB irradiation, were also effectively reduced by FA-HA. Additionally, FA-HA treatment decreases the phosphorylation of mitogen-activated protein kinase (MAPK) and activator protein-1 (AP-1), ultimately preventing apoptosis. These findings suggest that FA-HA is a promising candidate for UVB protection in skincare formulations.


Sujet(s)
Survie cellulaire , Acides coumariques , Cellules HaCaT , Acide hyaluronique , Espèces réactives de l'oxygène , Rayons ultraviolets , Humains , Acides coumariques/pharmacologie , Acides coumariques/composition chimique , Rayons ultraviolets/effets indésirables , Survie cellulaire/effets des médicaments et des substances chimiques , Acide hyaluronique/pharmacologie , Acide hyaluronique/composition chimique , Espèces réactives de l'oxygène/métabolisme , Cytokines/métabolisme , Antioxydants/pharmacologie , Antioxydants/composition chimique , Radioprotecteurs/pharmacologie , Radioprotecteurs/composition chimique , Stress oxydatif/effets des médicaments et des substances chimiques , Stress oxydatif/effets des radiations , Superoxide dismutase/métabolisme , Polymères/composition chimique , Polymères/pharmacologie
3.
J Am Chem Soc ; 146(40): 27713-27724, 2024 Oct 09.
Article de Anglais | MEDLINE | ID: mdl-39324482

RÉSUMÉ

The activity of the electrocatalytic CO2 reduction reaction (CO2RR) is substantially affected by alkali metal cations (AM+) in electrolytes, yet the underlying mechanism is still controversial. Here, we employed electrochemical scanning tunneling microscopy and in situ observed Au(111) surface roughening in AM+ electrolytes during cathodic polarization. The roughened surface is highly active for catalyzing the CO2RR due to the formation of surface low-coordinated Au atoms. The critical potential for surface roughening follows the order Cs+ > Rb+ > K+ > Na+ > Li+, and the surface proportion of roughened area decreases in the order of Cs+ > Rb+ > K+ > Na+ > Li+. Electrochemical CO2RR measurements demonstrate that the catalytic activity strongly correlates with the surface roughness. Furthermore, we found that AM+ is critical for surface roughening to occur. The results unveil the unrecognized effect of AM+ on the surface structural evolution and elucidate that the AM+-induced formation of surface high-activity sites contributes to the enhanced CO2RR in large AM+ electrolytes.

4.
Bioresour Technol ; 414: 131492, 2024 Sep 27.
Article de Anglais | MEDLINE | ID: mdl-39343177

RÉSUMÉ

Although Bacillus subtilis shows promise as a potential microbial cell factory for phospholipase D (PLD) expression, its production capacity remains insufficient. In this study, a secretory expression system, by co-optimization the promoter and signal peptides and employing a fed-batch fermentation strategy, was constructed to enhance expression of PLD from separate sources. The highest PLD production of 4056.9 U/mL was observed using this system, with a PLD production efficiency of 52.0 U/mL/h. Finally, a phosphatidic acid (PA) biosynthesis system was established using the constructed PLD as a catalyst, which achieved a PA yield of 219.1 g/L. This is the highest PLD production and PA yield reported globally to date. The protocol has significant potential for application for industrial PLD production as well as enzymatic phospholipids modification and also provides a valuable reference for overexpressing proteins in B. subtilis.

5.
Nature ; 634(8032): 69-73, 2024 Oct.
Article de Anglais | MEDLINE | ID: mdl-39294380

RÉSUMÉ

Studies of moiré systems have explained the effect of superlattice modulations on their properties, demonstrating new correlated phases1. However, most experimental studies have focused on a few layers in two-dimensional systems. Extending twistronics to three dimensions, in which the twist extends into the third dimension, remains underexplored because of the challenges associated with the manual stacking of layers. Here we study three-dimensional twistronics using a self-assembled twisted spiral superlattice of multilayered WS2. Our findings show an opto-twistronic Hall effect driven by structural chirality and coherence length, modulated by the moiré potential of the spiral superlattice. This is an experimental manifestation of the noncommutative geometry of the system. We observe enhanced light-matter interactions and an altered dependence of the Hall coefficient on photon momentum. Our model suggests contributions from higher-order quantum geometric quantities to this observation, providing opportunities for designing quantum-materials-based optoelectronic lattices with large nonlinearities.

6.
JACS Au ; 4(9): 3400-3412, 2024 Sep 23.
Article de Anglais | MEDLINE | ID: mdl-39328772

RÉSUMÉ

Perovskite solar cells (PSCs) are recognized as one of the most promising next-generation photovoltaics, primarily due to their exceptional power conversion efficiency, ease of processing, and cost-effectiveness. Despite these advantages, challenges remain in achieving high-quality films and ensuring the long-term stability of PSCs, which hinder their widespread commercialization. Polymers, characterized by multifunctional groups, superior thermal stability, flexible long chains, and cross-linking capabilities, offer significant potential to enhance the performance and reliability of PSCs. This review comprehensively presents the multifaceted roles that polymers play in PSCs. Through carefully controlling interactions between polymers and perovskites, crucial aspects such as film crystallization kinetics, carrier transport process, ion migration issues, and mechanical properties under bending can be effectively regulated to maximize the device performance. Furthermore, the hydrophobic properties and strong chelated cross-linking networks of polymers significantly enhance the stability of PSCs under various environmental conditions while effectively mitigating lead leakage, thereby addressing environmental concerns and long-term durability. Moreover, this Perspective identifies potential pathways for further advancing polymer-based strategies in PSC applications.

7.
J Environ Manage ; 370: 122662, 2024 Sep 26.
Article de Anglais | MEDLINE | ID: mdl-39332300

RÉSUMÉ

Algae play critical roles in the carbon dioxide (CO2) exchange between the water bodies and the atmosphere. However, the effects of prokaryotic and eukaryotic algae on carbon utilization, CO2 flux, and the underlying mechanisms remain poorly understood. Therefore, this study investigated the differences in carbon preferences and CO2 fluxes under different algal dominance days. Our research revealed that dissolved inorganic carbon (DIC) concentration fluctuations had a limited effect on the relative abundance of algae. However, shifts in dominant algal phyla induced changes in DIC, with Cyanobacteria preferring HCO3- and Chlorophyta preferring CO2. Analysis of the water chemistry balance indicated that the growth of Chlorophyta had a 15.59 times greater effect on CO2 sinks compared with that of Cyanobacteria. During the Cyanobacteria dominance days, the lower DIC concentration did not result in a reduction in CO2 emissions. However, increases in the dissolved organic carbon concentration provided a favorable environment for Cyanobacteria, which promoted CO2 emissions. The CCM model indicated that the growth of Chlorophyta resulted in CO2 uptake rates at least 3.57 times higher and CO2 leakage rates up to 0.97 times lower compared to Cyanobacteria, accelerating CO2 transport into the cell. Overall, CO2 sink was stronger on Chlorophyta dominance days than on Cyanobacteria dominance days. This study emphasized the influence of algal phyla on CO2 fluxes, revealing the significant CO2 sink associated with Chlorophyta. Further research should investigate how to manipulate environmental factors to favor Chlorophyta growth and effectively reduce CO2 emissions.

8.
BMC Public Health ; 24(1): 2642, 2024 Sep 27.
Article de Anglais | MEDLINE | ID: mdl-39334056

RÉSUMÉ

BACKGROUND: Oxidative Balance Scores (OBS) is composite measures that assess the balance between pro-oxidant and antioxidant factors in an individual's diet and lifestyle. Evidence on OBS and cardiovascular disease (CVD) in diabetic patients is scarce. This study investigates the potential association between OBS and CVD-prevalence and all-cause and CVD-related mortality in adult diabetic patients. METHODS: Participants were selected from the National Health and Nutrition Examination Survey (NHANES) 2007-2018. OBS-related data collection was initiated by linking the National Death Index to determine mortality due to all-cause and cardiovascular disease until December 31, 2019. Weighted logistic regression analyses explored the relationship between OBS and CVD. In addition, multivariable Cox proportional risk regression models and Kaplan-Meier curves were used to determine the correlation between OBS and mortality, with time to event as the time variable, as well as to estimate hazard ratios (HR) and 95% confidence interval (CI). RESULTS: A total of 3491 participants were included in the final analysis. Weighted logistic regression analysis of the relationship between OBS and CVD prevalence found that higher OBS was not associated with CVD prevalence compared with lower levels after fully adjustment in model 3 (OR: 0.82, 95% CI: 0.51-1.31, P = 0.39). During 3,491 person-years of follow-up, 408 deaths were recorded, of which 105 deaths were attributed to CVD. In fully adjusted model 3, participants in the highest quartile of OBS had significant reductions in all-cause mortality of 53% [HR: 0.47, 95% CI: 0.29-0.77), Ptrend= 0.002] and in cardiovascular disease mortality of 78% [HR: 0.22, 95% CI: 0.08-0.56), Ptrend= 0.004], compared with the lowest quartile groups of OBS. The Kaplan-Meier analysis results showed that participants in the highest quartile of OBS had the lowest risk of all-cause and CVD-related mortality and were statistically different (P < 0.05). Subgroup analysis confirmed that P for interaction was significant only concerning the educational level attained and in individuals with a history of CKD (P < 0.05). CONCLUSIONS: Although OBS wasn't very useful for assessing CVD prevalence outcomes, higher OBS was significantly associated with lower all-cause and CVD-related mortality, suggesting that maintaining adequate OBS may reduce mortality in patients with DM.


Sujet(s)
Maladies cardiovasculaires , Diabète de type 2 , Enquêtes nutritionnelles , Humains , Maladies cardiovasculaires/mortalité , Mâle , Femelle , Adulte d'âge moyen , Diabète de type 2/mortalité , Adulte , Sujet âgé , Cause de décès , Stress oxydatif , États-Unis/épidémiologie , Prévalence
9.
Org Lett ; 26(38): 8069-8073, 2024 Sep 27.
Article de Anglais | MEDLINE | ID: mdl-39284123

RÉSUMÉ

Acinetobacter baumannii poses a serious threat to human health. Pathogenic bacterial lipopolysaccharides (LPSs) are potent immunogens for the development of antibacterial vaccines. To investigate the antigenic properties of A. baumannii LPS, five well-defined core oligosaccharide fragments from the LPS of A. baumannii SMAL and ATCC 19606 were synthesized. A divergent synthesis strategy based on orthogonally protected α-(2 → 5)-linked Kdo dimer 6 was developed. Selective exposure of different positions in this key precursor and then elongation of sugar chains via stereocontrolled formation of both 1,2-trans and 1,2-cis-2-aminoglycosidic linkages permitted the efficient synthesis of the targets. The synthetic route also highlights a 4-O and then 7-O glycosylation sequence for assembly of the novel 4,7-branched Kdo framework. Antigenicity assay using the glycan microarray technique disclosed that tetrasaccharide 3 featuring both 4,7-branch and α-(2 → 5)-Kdo-Kdo structural elements was a potential antigenic determinant.


Sujet(s)
Acinetobacter baumannii , Lipopolysaccharides , Oligosaccharides , Acinetobacter baumannii/composition chimique , Acinetobacter baumannii/immunologie , Lipopolysaccharides/composition chimique , Lipopolysaccharides/immunologie , Oligosaccharides/composition chimique , Oligosaccharides/synthèse chimique , Glycosylation , Structure moléculaire , Séquence glucidique , Humains
10.
Plant Signal Behav ; 19(1): 2399429, 2024 Dec 31.
Article de Anglais | MEDLINE | ID: mdl-39229864

RÉSUMÉ

Currently, applying lime to cadmium (Cd)-contaminated paddy fields to increase pH and reduce Cd availability is an effective method to control excessive Cd levels in rice grain. However, under hydroponic conditions, the impact of increased pH on Cd accumulation in different rice varieties remains unclear. This study employed three rice varieties (Yuzhenxiang, Shaoxiang 100, Xiangwanxian 12) with different Cd accumulation characteristics under different pH and long-term treatment with 1 µM CdCl2, to study the effect of pH on growth and Cd accumulation in different rice varieties. The result showed that as pH shifted from 5 to 8, the SPAD values, shoot dry weight, and plant height of the three rice varieties significantly decreased. The main root length, root volume, and root dry weight of Yuzhenxiang, and Shaoxiang100 significantly decreased. Conversely, the root architecture indicators of Xiangwanxian 12 did not change significantly. As for element accumulation, increasing the pH significantly increased the content of Mn in both the shoots and roots of all three varieties. Yuzhenxiang significantly reduced Cd content in both the shoots and roots of rice, while Shaoxiang100 significantly increased Cd content in both parts. Xiangwanxian 12 showed a significant increase in Cd content in the shoots but a decrease in the roots. In terms of subcellular distribution, Yuzhenxiang significantly reduced Cd concentrations in the cell wall and organelles of root cells, resulting in lower Cd concentrations in the root tissue. Conversely, Shaoxiang100 significantly increased Cd concentrations in the cell wall, organelles, and soluble fractions of root cells, leading to higher Cd concentrations in the root tissue. Xiangwanxian 12 also exhibited a decrease in Cd concentrations in the cell wall, organelles, and soluble fraction of root cells, resulting in lower Cd concentrations in the root tissue. Additionally, the expression of the OsNRAMP5 and OsHMA3 gene was significantly increased in Shaoxiang 100, while no significantly change in Yuzhenxiang and Xiangwanxian 12. These results provide important guidance on the impact of pH on Cd accumulation during the vegetative growth stage of different rice varieties.


Sujet(s)
Cadmium , Culture hydroponique , Oryza , Racines de plante , Oryza/métabolisme , Oryza/croissance et développement , Oryza/effets des médicaments et des substances chimiques , Cadmium/métabolisme , Concentration en ions d'hydrogène , Racines de plante/métabolisme , Racines de plante/croissance et développement , Racines de plante/effets des médicaments et des substances chimiques , Pousses de plante/métabolisme , Pousses de plante/croissance et développement , Pousses de plante/effets des médicaments et des substances chimiques
11.
ACS Synth Biol ; 13(9): 2887-2898, 2024 Sep 20.
Article de Anglais | MEDLINE | ID: mdl-39262282

RÉSUMÉ

Genomic integration of heterologous genes is the preferred approach in industrial fermentation-related strains due to the drawbacks associated with plasmid-mediated microbial fermentation, including additional growth burden, genetic instability, and antibiotic contamination. Synthetic biology and genome editing advancements have made gene integration convenient. Integrated expression is extensively used in the field of biomanufacturing and is anticipated to become the prevailing method for expressing recombinant proteins. Therefore, it is pivotal to strengthen the expression of exogenous genes at the genome level. Here, we systematically optimized the integrated expression system of Escherichia coli from 3 aspects. First, the integration site slmA with the highest expression activity was screened out of 18 sites in the ORI region of the E. coli BL21 (DE3) genome. Second, we characterized 16 endogenous promoters in E. coli and combined them with the T7 promoter. A constitutive promoter, Plpp-T7, exhibited significantly higher expression strength than the T7 promoter, achieving a 3.3-fold increase in expression levels. Finally, to further enhance the T7 expression system, we proceeded with overexpression of T7 RNA polymerase at the chassis cell level. The resulting constitutive efficient integrated expression system (CEIES_Ecoli) showed a 2-fold increase in GFP expression compared to the pET3b recombinant plasmid. Therefore, CEIES_Ecoli was applied to the integrated expression of nitrilase and hyaluronidase, achieving stable and efficient enzyme expression, with enzyme activities of 22.87 and 12,195 U·mL-1, respectively, comparable to plasmid levels. Overall, CEIES_Ecoli provides a stable and efficient method of gene expression without the need for antibiotics or inducers, making it a robust tool for synthetic biology, enzyme engineering, and related applications.


Sujet(s)
DNA-directed RNA polymerases , Escherichia coli , Plasmides , Régions promotrices (génétique) , Escherichia coli/génétique , Escherichia coli/métabolisme , Régions promotrices (génétique)/génétique , DNA-directed RNA polymerases/génétique , DNA-directed RNA polymerases/métabolisme , Plasmides/génétique , Protéines recombinantes/génétique , Protéines recombinantes/biosynthèse , Protéines recombinantes/métabolisme , Biologie synthétique/méthodes , Protéines virales/génétique , Protéines virales/métabolisme , Protéines à fluorescence verte/génétique , Protéines à fluorescence verte/métabolisme
12.
BMC Oral Health ; 24(1): 1102, 2024 Sep 17.
Article de Anglais | MEDLINE | ID: mdl-39289711

RÉSUMÉ

BACKGROUND/PURPOSE: This retrospective immunohistological pilot study aimed to investigate the influence of natural killer group 2, member D (NKG2D) ligand expression on ameloblastoma recurrence after surgical resection. It also aimed to elucidate additional clinical factors that could serve as predictors of ameloblastoma recurrence. MATERIALS AND METHODS: This study included 96 patients who were histologically diagnosed with ameloblastoma after surgical resection. The expression of NKG2D ligands, including UL16-binding proteins (ULBPs) 1-3 and major histocompatibility complex class I chain-related molecule (MIC) A/B, was evaluated in formalin-fixed paraffin-embedded tumor tissues via immunohistochemistry assays. Furthermore, the patients' electronic medical records were reviewed. Multivariate Cox regression analysis was conducted, and data were expressed as adjusted hazard ratios [HRs] with 95% confidence intervals [95% CIs]. RESULTS: Multivariate analysis revealed that recurrent tumors (ref.: primary; adjusted HR [95% CI]: 2.780 [1.136, 6.803], p = 0.025) and positive MICA/B expression (ref.: negative; adjusted HR [95% CI]: 0.223 [0.050, 0.989], p = 0.048) independently affected recurrence-free survival in ameloblastoma. CONCLUSION: This study identified recurrent cases and loss of MICA/B expression as independent predictors of early ameloblastoma recurrence following surgical resection. The findings suggest that decreased MICA/B expression might undermine NKG2D-mediated tumor immunosurveillance, thereby influencing early recurrence.


Sujet(s)
Améloblastome , Récidive tumorale locale , Humains , Études rétrospectives , Mâle , Femelle , Récidive tumorale locale/anatomopathologie , Projets pilotes , Adulte d'âge moyen , Améloblastome/anatomopathologie , Améloblastome/métabolisme , Améloblastome/chirurgie , Adulte , Sous-famille K des récepteurs de cellules NK de type lectine/métabolisme , Sujet âgé , Immunohistochimie , Adolescent , Tumeurs de la mâchoire/anatomopathologie , Tumeurs de la mâchoire/métabolisme , Tumeurs de la mâchoire/chirurgie , Jeune adulte
13.
Water Res X ; 25: 100253, 2024 Dec 01.
Article de Anglais | MEDLINE | ID: mdl-39291147

RÉSUMÉ

Efficient carbon use is crucial for biological nitrogen removal. Traditional aerobic processes can waste carbon sources, exacerbating carbon deficiency. This study explores an anaerobic/oxic/anoxic system with sludge double recirculation to improve nitrogen removal in low C/N wastewater. This system integrated aerobic nitrification after the carbon intracellular storage, separating carbon and nitrogen by denitrifying glycogen-accumulating organisms (DGAOs) with endogenous partial denitrification and Anammox within the anoxic units. A significant efficiency of 91.02±7.01% chemical oxygen demand (COD) was converted into intracellular carbon in anaerobic units, significantly reducing carbon futile oxidation in the aerobic units by effectively separating COD from ammonia. Intracellular storage of carbon sources and microbial adaptation to carbon scarcity prevent futile oxidation of COD in the aerobic units even with short-term high dissolved oxygen (DO), thereby enhancing nitrogen removal under anoxic conditions with sufficient intracellular carbon source. The microbial analysis identified Candidatus Brocadia as the dominant anammox bacteria, in combination with the activity of DGAOs and other related microbial communities, accounting for 37.0% of the TN removal. Consequently, the system demonstrated remarkable nitrogen removal efficiencies, achieving 81.3±3.3% for total nitrogen (TN) and 98.5±0.9% for ammonia nitrogen while maintaining an effluent COD concentration of 17.2±9.1 mg/L, treating the low C/N of 4.18 in the influent wastewater. The findings in this study provide a sustainable and energy-saving technique for conventional WWTPs to meet strict discharge standards by avoiding futile oxidation of COD and encouraging anammox contributions.

14.
Food Sci Technol Int ; : 10820132241271798, 2024 Sep 19.
Article de Anglais | MEDLINE | ID: mdl-39295422

RÉSUMÉ

This study aimed to investigate the impact of slightly acidic electrolyzed water combined with lithium magnesium silicate hydrosol on the quality of fresh slices of Gastrodia elata under varying storage temperatures, including room temperature fresh slices of Gastrodia elata 25 °C and 37 °C. Fresh slices of Gastrodia elata 25 and 37 samples were stored for 13 days and extensively analyzed for color, weight loss, decay index, bacterial count, vitamin C, and polysaccharide contents during different storage periods. The findings revealed that the slightly acidic electrolyzed water + hydrosol treatment notably decreased weight loss and decay index compared to distilled water and slightly acidic electrolyzed water treatments. Moreover, fresh slices of Gastrodia elata treated with slightly acidic electrolyzed water + hydrosol exhibited untraceable bacterial counts after 3 days, with counts starting to increase after 7 days of storage. The bacterial counts rose from 3.25 to 5.36 and from 4.13 to 5.79 log CFU/g under both storage conditions. The application of slightly acidic electrolyzed water + hydrosol resulted in reduced chromaticity values of L*, a*, and b* on the Gastrodia elata surface, along with a lower percentage loss of polysaccharide contents and vitamin C compared to distilled water and slightly acidic electrolyzed water treatments. These results suggested that Gastrodia elata treated with slightly acidic electrolyzed water + hydrosol maintained its quality characteristics and nutritional attributes, exhibiting greater stability during storage.

15.
Adv Sci (Weinh) ; : e2402020, 2024 Sep 19.
Article de Anglais | MEDLINE | ID: mdl-39297298

RÉSUMÉ

Carbon corrosion poses a significant challenge in polymer exchange membrane fuel cells (PEMFCs), leading to reduced cell performance due to catalyst layer degradation and catalyst detachment from electrodes. A promising approach to address this issue involves incorporating an anticorrosive carbon material into the oxygen reduction reaction (ORR) electrode, even in small quantities (≈3 wt% in electrode). Herein, the successful synthesis of fluorine-doped graphene nanoribbons (F-GNR) incorporated with graphitic carbon nanotubes (F-GNR@CNT), demonstrating robust resistance to carbon corrosion is reported. By controlling the synthesis conditions using an exfoliation method, the properties of the composite are tailored. Electronic structural studies, employing density functional theory (DFT) calculations, to elucidate the roles of fluorine dopants and graphitic carbon nanotubes (CNTs) in mitigating carbon corrosion are conducted. Physicochemical and electrochemical characterization of F-GNR@CNT reveal its effectiveness as a cathode additive at the single-cell scale. The addition of F-GNR@CNT to the Pt/C cathode improves durability by enhancing carbon corrosion resistance and water management, thus mitigating the flooding effect through tailored surface properties. Furthermore, advanced impedance analysis using a transmission line model is performed to gain insights into the internal resistance and capacitive properties of electrode structure.

16.
Angew Chem Int Ed Engl ; : e202413429, 2024 Sep 09.
Article de Anglais | MEDLINE | ID: mdl-39252053

RÉSUMÉ

The lanthanide contraction involves a reduction in atomic radius among f-block elements below the expected level. A similar contraction is observed in group-16 elements. The atomic radius of Se (117 pm) is slightly larger than that of S (104 pm) arising from the presence of d electrons, compared to the significant increase in atomic radius from O (73 pm) to S. This lanthanide-like contraction contributes to Se's robust oxidative resistance. Here we report a selective oxidation strategy utilizing Se's strong antioxidative property to remove coexisting narrow-bandgap Te impurities from Se feedstocks. This strategy selectively oxidizes volatile Te impurities into involatile TeO2 that remains in the evaporation source, while only volatile Se deposits onto the substrate during the thermal-evaporation deposition process. This enables the fabrication of high-purity Se films possessing a wide bandgap of 1.88 eV, ideally suited to the optimal bandgap for indoor photovoltaics (IPVs). The resulting Se photovoltaics exhibit an efficiency of 20.1% under 1000-lux indoor illumination, outperforming market-dominant amorphous silicon and all types of lead-free perovskite IPVs. Unencapsulated Se devices show no efficiency degradation after 20,000 hours of storage in ambient atmosphere.

17.
Ying Yong Sheng Tai Xue Bao ; 35(7): 1866-1876, 2024 Jul 18.
Article de Anglais | MEDLINE | ID: mdl-39233416

RÉSUMÉ

The lower limit temperature in the crop water stress index (CWSI) model refers to the canopy temperature (Tc) or the canopy-air temperature differences (dT) under well-watered conditions, which has significant impacts on the accuracy of the model in quantifying plant water status. At present, the direct estimation of lower limit temperature based on data-driven method has been successfully used in crops, but its applicability has not been tes-ted in forest ecosystems. We collected continuously and synchronously Tc and meteorological data in a Quercus variabilis plantation at the southern foot of Taihang Mountain to evaluate the feasibility of multiple linear regression model and BP neural network model for estimating the lower limit temperature and the accuracy of the CWSI indicating water status of the plantation. The results showed that, in the forest ecosystem without irrigation conditions, the lower limit temperature could be obtained by setting soil moisture as saturation in the multiple linear regression mo-del and the BP neural network model with soil water content, wind speed, net radiation, vapor pressure deficit and air temperature as input parameters. Combining the lower limit temperature and the upper limit temperature determined by the theoretical equation to normalize the measured Tc and dT could realize the non-destructive, rapid, and automatic diagnosis of the water status of Q. variabilis plantation. Among them, the CWSI obtained by combining the lower limit temperature determined by the dT under well-watered condition calculated by the BP neural network model and the upper limit temperature was the most suitable for accurate monitoring water status of the plantation. The coefficient of determination, root mean square error, and index of agreement between the calculated CWSI and measured CWSI were 0.81, 0.08, and 0.90, respectively. This study could provide a reference method for efficient and accurate monitoring of forest ecosystem water status.


Sujet(s)
Quercus , Température , Eau , Quercus/croissance et développement , Eau/analyse , Chine , 29935 , Écosystème , Modèles théoriques , Stress physiologique , Forêts
18.
Front Genet ; 15: 1292249, 2024.
Article de Anglais | MEDLINE | ID: mdl-39268080

RÉSUMÉ

Background: Ubiquitination, a major post-translational modification, significantly impacts tumorigenesis, progression, and prognosis. This study aims to classify colon cancer at the molecular level and create a reliable signature using ubiquitination-related genes (URGs) to assess the immune microenvironment and prognosis. Methods: We employed non-negative matrix factorization to subtype colon cancer based on ubiquitination-related gene (URG) expression patterns. Quantitative scores for 28 immune cell infiltrates and the tumor microenvironment were computed using single-sample gene set enrichment analysis (ssGSEA) and the Estimate algorithm. Subtype feature genes were selected through Lasso logistic regression and SVM-RFE algorithm. The ubiquitination-related signature was constructed using univariate Cox, Lasso, and stepwise regression methods to categorize patients into high and low-risk groups. Validation included log-rank tests, receiver operating characteristic (ROC) analysis, decision curve analysis (DCA), and external dataset validation. Immune therapy response was compared using Tumor Immune Dysfunction and Exclusion (TIDE), Immunophenoscore (IPS), and submap analyses. Clinical variables and risk scores were integrated into an enhanced nomogram. The early diagnostic value of four URGs was confirmed via quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry. The cell proliferation was assessed through colony formation, EdU staining, and xenograft tumorigenesis assays. Results: Prognostic ubiquitination-related genes (URGs) stratified patients into subtypes, revealing differences in survival, immune cell infiltration, and pathological staging. A signature of 6 URGs (ARHGAP4, MID2, SIAH2, TRIM45, UBE2D2, WDR72) was identified from 57 subtype-related genes. The high-risk group exhibited characteristics indicative of enhanced epithelial-mesenchymal transition, immune escape, immunosuppressive myeloid-derived suppressor cells, regulatory T cell infiltration, and lower immunogenicity. In contrast, the low-risk group demonstrated the opposite trend but showed a better response to CTLA4 checkpoint inhibitors. The predictive performance of the nomogram significantly improved with the integration of risk score, stage, and age. ARHGAP4 and SIAH2 exhibit promising early diagnostic capabilities. Additionally, WDR72 knockdown significantly inhibited CRC cell proliferation both in vitro and in vivo. Conclusion: Our developed ubiquitination-related signature and genes serve as promising biomarkers for colon cancer prognosis, immune microenvironment, and diagnosis.

19.
J Vasc Access ; : 11297298241254635, 2024 Aug 08.
Article de Anglais | MEDLINE | ID: mdl-39113549

RÉSUMÉ

PURPOSE: Totally implanted venous access device are widely used for long-term chemotherapy in cancer patients. Previous studies have only focused on the analysis of complications associated with infusion port implantation, ignoring the causes of unsuccessful infusion port implantation. The purpose of this study was to investigate the association between body mass index (BMI) and the success rate of transaxillary intravenous port implantation in breast cancer patients. MATERIALS AND METHODS: To review 361 breast cancer patients who underwent intravenous port implantation from January 2021 to September 2021. Baseline data, and surgical data were collected from the patients, and the success rate of puncture of the axillary vein was recorded. The logistic regression analysis and smoothed curve fitting were used to assess the relationship between BMI and the success rate of axillary venipuncture. In addition, subgroup analyses were performed to explore potential interactions. RESULTS: Under ultrasound guidance, 67.3% of patients (243/361) had an infusion port implanted by axillary vein puncture. There was a roughly linear relationship between BMI and the success rate of axillary venipuncture. In the multiple regression equation, BMI was significantly and negatively associated with the success rate of axillary venipuncture (OR = 0.83; 95% CI = 0.77-0.89; p < 0.001). Stratified analysis showed that the relationship between BMI and the success rate of axillary venipuncture was stable and unaffected by other variables. CONCLUSIONS: The higher the patient's BMI, the higher the chance of difficult axillary venipuncture or failed cannulation.

20.
World J Gastroenterol ; 30(26): 3261-3263, 2024 Jul 14.
Article de Anglais | MEDLINE | ID: mdl-39086637

RÉSUMÉ

This letter to the editor relates to the study entitled "Tenofovir amibufenamide vs tenofovir alafenamide for treating chronic hepatitis B: A real-world study", which was recently published by Peng et al. Hepatitis B virus infection represents a significant health burden worldwide and can lead to cirrhosis and even liver cancer. The antiviral drugs currently used to treat patients with chronic hepatitis B infection still have many side effects, so it is crucial to identify safe and effective drugs to inhibit viral replication.


Sujet(s)
Antiviraux , Virus de l'hépatite B , Hépatite B chronique , Ténofovir , Humains , Antiviraux/usage thérapeutique , Antiviraux/effets indésirables , Hépatite B chronique/traitement médicamenteux , Hépatite B chronique/virologie , Ténofovir/usage thérapeutique , Ténofovir/analogues et dérivés , Ténofovir/effets indésirables , Virus de l'hépatite B/effets des médicaments et des substances chimiques , Résultat thérapeutique , Réplication virale/effets des médicaments et des substances chimiques , Adénine/analogues et dérivés , Adénine/usage thérapeutique , Adénine/effets indésirables , Alanine/analogues et dérivés , Alanine/usage thérapeutique , Alanine/effets indésirables
SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE