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1.
J Stomatol Oral Maxillofac Surg ; : 101947, 2024 Jun 09.
Article in English | MEDLINE | ID: mdl-38857692

ABSTRACT

OBJECTIVE: For patients with clinical nodal-negative (cN0) maxillary oral squamous cell carcinoma (MOSCC), neck dissection (ND) and clinical observation are the main two management strategies for the neck. However, the indications corresponding to these two options remain controversial. This study aimed to elucidate the clinical factors affecting ND treatment and to identify clinical characteristics of the population that may benefit from ND based on a retrospective analysis of cN0 MOSCC patient data from the Surveillance, Epidemiology, and End Results (SEER) database. METHODS: 8846 MOSCC patients were identified in the SEER database from 2000 to 2020. The Kaplan-Meier method was utilized to examine overall survival (OS) and disease-specific survival (DSS), while the hazard ratio (HR) was estimated using the stepwise multivariate Cox regression model. Furthermore, multi-subgroup analyses of DSS and OS were performed to compare ND and No ND. RESULTS: We included 2,512 cN0 MOSCC patients. Basic survival analysis and Cox regression modeling showed that ND was an independent prognostic factor that promoted DSS and OS. Additional subgroup analyses revealed that the primary site and T-stage might influence the efficacy of ND modality. Moreover, patients with T3/T4 stage of upper gingival squamous cell carcinoma (UGSCC) (DSS p = 0.009, OS p = 0.004), hard palate squamous cell carcinoma (HPSCC) (DSS p = 0.001, OS p < 0.001), and soft palate squamous cell carcinoma (SPSCC) (p = 0.029) showed a better survival benefit with ND in OS and DSS. Nonetheless, no differences were observed in OS and DSS between ND and No ND at the T1/T2 stage of the abovementioned primary tumor sites. Additionally, the DSS outcomes for T1/T2 stage upper lip squamous cell carcinoma (ULSCC) patients were significantly worse in the ND group than in the No ND group (p = 0.018). However, no significant differences were noted in OS (p = 0.140) as well as OS (p = 0.248) and DSS (p = 0.627) for T1/T2 and T3/T4 patients, respectively. CONCLUSION: Active surveillance might be a feasible strategy for managing all T-staged ULSCC as well as early-stage (T1/T2) UGSCC, SPSCC, and HPSCC, provided regular and meticulous follow-up is performed. Hence, concurrent ND is recommended for patients with intermediate to advanced (T3/T4) stage UGSCC, SPSCC, and HPSCC.

2.
Front Microbiol ; 15: 1371208, 2024.
Article in English | MEDLINE | ID: mdl-38841054

ABSTRACT

Background: Desert steppe ecosystems are prone to drought stress, which influences the ecological balance and sustainable development of grasslands. In addition to directly restrict plant growth, drought stress indirectly impacts plant fitness by altering the diversity and function of root-associated microbiomes. This begs the question of whether the functional microbiome of forage plants, represented by synthetic microbial communities (SynComs), can be leveraged to mitigate drought stress in desert steppes and promote the ecological restoration of these fragile ecosystems. Methods: A pot experiment was conducted to evaluate the role of SynComs in improving the plant growth and drought stress resistance of Neopallasia pectinata (Pall.) Poljak in desert steppe in Inner Mongolia, China. Six SynComs were derived from the rhizosphere and root endosphere of 12 dominant forage species in the desert steppe. Each SynCom comprised two to three bacterial genera (Bacillus, Protomicromonospora, and Streptomyces). We examined the capacities of different SynComs for nutrient solubilization, phytohormone secretion, and enzymatic activity. Results: Under no water stress (75% soil water holding capacity, WHC), single strains performed better than SynComs in promoting plant growth in terms of stem diameter, root length, and plant dry weight, with the greatest effects observed for Streptomyces coeruleorubidus ATCC 13740 (p < 0.05). However, under mild to moderate drought stress (55% and 35% WHC), SynComs outperformed single strains in enhancing plant biomass accumulation and inducing the production of resistance-related substances (p < 0.05). No significant effect of single strains and SynComs emerged under extreme drought stress (20% WHC). Conclusion: This study underscores the potential of SynComs in facilitating forage plants to combat drought stress in desert steppe. Mild to moderate drought stress stimulates SynComs to benefit the growth of N. pectinata plants, despite a soil moisture threshold (21% WHC) exists for the microbial effect. The use of SynComs provides a promising strategy for the ecological restoration and sustainable utilization of desert steppes by manipulating the functional microbiome of forage plants.

3.
Opt Express ; 32(9): 15645-15657, 2024 Apr 22.
Article in English | MEDLINE | ID: mdl-38859210

ABSTRACT

The spectral emission of laser-induced plasma in water has a broadband continuum containing ultraviolet light, which can be used as a novel light source for the degradation of organic compounds. We studied the degradation process of the organic dye Rhodamine B (RhB) using plasma light source excited by the "Laser + Fe" mode. Spectral analysis and reaction kinetics modelling were used to study the degradation mechanism. The degradation process using this light source could be divided into two stages. The initial stage was mainly photocatalytic degradation, where ultraviolet light broke the chemical bond of RhB, and then RhB was degraded by the strong oxidising ability of ·OH. As the iron and hydrogen ion concentrations increased, the synergistic effect of photocatalysis and the Fenton reaction further enhanced the degradation rate in the later stage. The plasma excited by the "Laser + Fe" mode achieved photodegradation by effectively enhancing the ultraviolet wavelength ratio of the emission spectrum and triggered the Fenton reaction to achieve rapid organic matter degradation. Our findings indicate that the participation of the Fenton reaction can increase the degradation rate by approximately 10 times. Besides, the impact of pH on degradation efficiency demonstrates that both acidic and alkaline environments have better degradation effects than neutral conditions; this is because acidic environments can enhance the Fenton reaction, while alkaline environments can provide more ·OH.

4.
Opt Express ; 32(12): 21304-21326, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38859488

ABSTRACT

Precious metal doping can effectively improves the catalytic performance of TiO2. In this study, pulsed laser ablation in liquid (PLAL) is employed to integrate preparation with doping and control composite nanoparticle products by adjusting the laser action time to synthesise Ag-TiO2 composite nanoparticles with high catalytic performance. The generation and evolution of Ag-TiO2 nanoparticles are investigated by analysing particle size, microscopic morphology, crystalline phase, and other characteristics. The generation and doped-morphology evolution of composite nanoparticles are simulated based on thermodynamics, and the optimisation of Ag-doped structure on the composite nanomaterials is investigated based on density functional theory. The effect of Ag-TiO2 structural properties on its performance is examined under different catalytic conditions to determine optimal degradation conditions. In this study, the effect of laser ablation time on the doped structure during PLAL is analysed, which is of further research significance in exploring the structural evolution law of laser and composite nanoparticles, multi-variate catalytic performance testing, reduction of photogenerated carrier complexation rate, and expansion of its spectral absorption range, thereby providing the basis for practical production.

5.
Acta Neurol Belg ; 124(3): 973-979, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38523222

ABSTRACT

PURPOSE: In addition to epilepsy, individuals with tuberous sclerosis complex (TSC) experience a wide range of behavioral, psychiatric, intellectual, academic, and psychosocial problems. They usually exert a large psychological burden on individuals with these illnesses. METHODS: This cross-sectional study used TSC-associated neuropsychiatric disorders (TAND) checklist interviews conducted at a single medical center. The enrollment of all subjects was > 6 years, and the comorbidities of neurodevelopmental disorders were assessed by clinical psychologists before enrollment. To assess the spectrum of TAND, the TAND checklist was applied as stated in the protocol, and the responses to the TAND checklist were evaluated by clinical psychologists. RESULTS: In the behavioral concerns of patients with TSC without epilepsy, those with epilepsy had excessive shyness, language delay, lack of eye contact, rigid behavior, inattentiveness, and restlessness. In psychiatric disorders, autism spectrum disorder and attention-deficit/hyperactivity disorder are significantly correlated with epilepsy history. Diminished academic skills, including reading, writing, and mathematics skills, are significantly associated with epilepsy history. For intellectual ability, TSC patients without epilepsy is associated normal intelligence level. Among neuropsychological skills, deficits in attention, dual tasking/multi-tasking, visuospatial tasking, and executive skills are significantly associated with epilepsy history. CONCLUSIONS: Epilepsy in patients with TSC contributes to comorbid neuropsychiatric disorders. In addition to epilepsy evaluation, it is crucial to evaluate the heterogeneous spectrum of neuropsychiatric disorders using a standard checklist during the annual clinical follow-up of patients with TSC.


Subject(s)
Checklist , Comorbidity , Epilepsy , Tuberous Sclerosis , Humans , Tuberous Sclerosis/complications , Tuberous Sclerosis/psychology , Tuberous Sclerosis/epidemiology , Epilepsy/psychology , Epilepsy/epidemiology , Female , Male , Cross-Sectional Studies , Child , Adolescent , Young Adult , Adult , Mental Disorders/epidemiology , Mental Disorders/etiology , Mental Disorders/psychology
6.
ACS Nano ; 18(13): 9670-9677, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38516986

ABSTRACT

Employing water as a hydrogen source to participate in the hydrogen atom transfer (HAT) process is a low-cost and carbon-free process demonstrating great economic and environmental potential in catalysis. However, the low efficiency of hydrogen atom abstraction from water leads to slow kinetics of HAT for most hydrogenative reactions. Here, we prepared ultrathin Bi4O5Cl2 nanosheets where the surface can be in situ reconstructed via hydroxylation under light illumination to facilitate the abstraction of hydrogen atoms from pure water for efficient nitrogen fixation. Consequently, the isotope labeling in situ Fourier-transform infrared spectroscopy (FT-IR) involving H2O and D2O has clearly revealed that the hydroxyl groups tend to be adsorbed on the chloride vacancy sites on the Bi4O5Cl2 surface to form hydroxylated surfaces, where the hydroxylated photocatalyst surface enables partial dehydrogenation of water into H2O2, allowing the utilization of H atoms for efficient of N2 hydrogenation via HAT steps. This work elucidates the in-depth reaction mechanism of hydrogen atom extraction from H2O molecules via the light-generated chloride vacancy to promote photocatalytic nitrogen fixation, ultimately enabling the inspiration and providing crucial rules for the design of important functional materials that can efficiently deliver active hydrogen for chemical synthesis.

7.
Sci Rep ; 14(1): 3264, 2024 02 08.
Article in English | MEDLINE | ID: mdl-38332050

ABSTRACT

The early development of the gut microbiome is governed by multiple factors and has significantly long-term effects on later-in-life health. To minimize inter-individual variations in the environment, we determined developmental trajectories of the gut microbiome in 28 healthy neonates during their stay at a postpartum center. Stool samples were collected at three time points: the first-pass meconium within 24 h of life, and at 7 and 28 days of age. Illumina sequencing of the V3-V4 region of 16S rRNA was used to investigate microbiota profiles. We found that there was a distinct microbiota structure at each time point, with a significant shift during the first week. Proteobacteria was most abundant in the first-pass meconium; Firmicutes and Actinobacteria increased with age and were substituted as the major components. Except for a short-term influence of different delivery modes on the microbiota composition, early microbiome development was not remarkably affected by gravidity, maternal intrapartum antibiotic treatment, premature rupture of membranes, or postnatal phototherapy. Hence, our data showed a similar developmental trajectory of the gut microbiome during the first month in healthy neonates when limited in environmental variations. Environmental factors external to the host were crucial in the early microbiome development.


Subject(s)
Gastrointestinal Microbiome , Microbiota , Infant, Newborn , Humans , Female , RNA, Ribosomal, 16S/genetics , Anti-Bacterial Agents/therapeutic use , Meconium/microbiology , Feces/microbiology
9.
Sci Rep ; 13(1): 23075, 2023 12 27.
Article in English | MEDLINE | ID: mdl-38155251

ABSTRACT

Unconjugated bilirubin (UB) levels during the first week after birth are related to outcomes in neonatal hypoxic-ischemic encephalopathy (HIE). Clinical Sarnat staging of HIE, brain magnetic resonance imaging (MRI), hearing outcomes, and neurodevelopmental outcomes ≥ 1 year were used to correlate UB in 82 HIE patients. The initial UB level was significantly correlated with lactic acid levels. The peak UB was higher (p < 0.001) in stage I (10.13 ± 4.03 mg/dL, n = 34) than in stages II and III (6.11 ± 2.88 mg/dL, n = 48). Among the 48 patients receiving hypothermia treatment, a higher peak UB was significantly (p < 0.001) correlated with unremarkable brain MRI scans and unremarkable neurodevelopmental outcomes at age ≥ 1 year. The peak UB were higher (P = 0.015) in patients free of seizures until 1 year of age (6.63 ± 2.91 mg/dL) than in patients with seizures (4.17 ± 1.77 mg/dL). Regarding hearing outcomes, there were no significant differences between patients with and without hearing loss. The UB level in the first week after birth is an important biomarker for clinical staging, MRI findings, seizures after discharge before 1 year of age, and neurodevelopmental outcomes at ≥ 1 year of age.


Subject(s)
Hypothermia, Induced , Hypoxia-Ischemia, Brain , Infant, Newborn , Humans , Hypoxia-Ischemia, Brain/diagnostic imaging , Hypoxia-Ischemia, Brain/therapy , Hypothermia, Induced/methods , Magnetic Resonance Imaging/methods , Seizures/therapy , Bilirubin
10.
Eur J Med Res ; 28(1): 607, 2023 Dec 19.
Article in English | MEDLINE | ID: mdl-38115154

ABSTRACT

BACKGROUND: Postinfarction cardiac remodeling presents a compensatory mechanism aimed at mitigating congestive heart failure. It is distinguished by progressive dilatation and hypertrophy of the ventricular chambers, fibrotic alterations, and prolonged apoptosis of cardiomyocytes. The primary objective of this study was to assess the effects of icariin on myocardial fibrosis and ventricular remodeling in rats subjected to myocardial infarction (MI). METHODS: Male Sprague‒Dawley (SD) rats were subjected to randomization and subsequently divided into distinct groups: the control group, the sham group (undergoing sham operation), the MI group (experiencing ligation of the left anterior descending artery), and the icariin group. Within the icariin group, rats were further categorized into three different dose groups based on the administered icariin dosage: the MI30 group (30 mg/kg/day), the MI60 group (60 mg/kg/day), and the MI120 group (120 mg/kg/day). Cardiac function evaluation was carried out using echocardiography. Histological examinations, including hematoxylin and eosin (HE) staining, Masson staining, and immunohistochemistry studies, were conducted 90 days after the occurrence of MI. Additionally, Western blotting was employed to assess TGF-ß1, p-Smad2, and p-Smad3 levels. RESULTS: The administration of icariin revealed a noteworthy enhancement in cardiac function among rats afflicted with left anterior descending coronary artery (LAD) ligation. In comparison to the icariin groups, the MI group exhibited reduced EF and FS, along with elevated LVEDD and LVESD. Furthermore, the cardiac fibrosis levels in the MI group rats exhibited a considerable increase compared to those in the icariin group. Notably, the levels of Collagen I, Collagen III, MMP2, and MMP9 were significantly higher in the MI group than in the icariin group, with evident distinctions. Moreover, the expression levels of TGF-ß, IL-13, p-Smad2, and p-Smad3 were notably upregulated in the MI group compared to the icariin group. CONCLUSIONS: In an experimental rat model of MI, the administration of icariin resulted in the amelioration of both cardiac function and remodeling processes, operating through the intricate TGF-ß1/Smad signaling pathway.


Subject(s)
Myocardial Infarction , Transforming Growth Factor beta1 , Rats , Animals , Male , Rats, Sprague-Dawley , Myocardial Infarction/drug therapy , Myocardial Infarction/pathology , Signal Transduction , Collagen , Ventricular Remodeling , Myocardium/metabolism
11.
Mol Neurobiol ; 2023 Dec 19.
Article in English | MEDLINE | ID: mdl-38110645

ABSTRACT

Depressive disorder is a severe and complex mental illness. There are a few anti-depressive medications that can reduce depressive symptoms, but with adverse or side effects. GaoYou-13 (GY-13), commonly known as Areca Thirteen Pill, is a traditional medicine for depression treatment with significant clinical impact. However, the molecular mechanism of GY-13 has not been fully elucidated. This study aimed to explore and explain the action and mechanism of GY-13 in treatment for depression. SD male rats were stimulated differently daily for 42 days to construct a depression rat model and divided into six groups: the control, CUMS model, GY-13L, GY-13 M, GY-13H, and FLUO. The body weight of was measured on day 7, 14, 21, 28, 35, and 42 or different days, and the behavioral tests (Open-field test, Sucrose preference test, Morris water maze) were made alongside. After the rats were decapitated, the rat brains were stained with Nissl or H&E dyes. The serums of TNF-α and IL-1ß were tested. The protein of p-IKKα, p-IкBα, and p-NFкBp65 was traced. Then nano-LC-MS/MS analysis was made to detect the mechanism of GY-13. The active ingredients, drug targets, and key pathways of GY-13 in treating depression were analyzed through network pharmacology and molecular docking. With immunohistochemistry, quantitative RT-PCR, and western-blot techniques, the therapeutic mechanism of GY-13 was traced and analyzed. This study revealed that GY-13 significantly enhances autonomous and exploratory behavior, sucrose consumption, learning and memory ability, and hippocampal neuronal degeneration, which inhibits inflammation. In addition, omics analysis showed several proteins were altered in the hippocampus of rats following CUMS and GY-13 treatment. Bioinformatics analysis and network pharmacology revealed the antidepressant effects of GY-13 are related to the chemokine/chemokine receptor axis. Immunohistochemistry, western blotting and RT-PCR assay further support the findings of omics analysis. We highlighted the importance of the chemokine/chemokine receptor axis in the treatment of depression, as well as showed GY-13 can be used as a novel targeted therapy for depression treatment.

12.
Environ Sci Technol ; 57(34): 12890-12900, 2023 08 29.
Article in English | MEDLINE | ID: mdl-37590166

ABSTRACT

An appealing strategy for ensuring environmental benefits of the photocatalytic NO oxidation reaction is to convert NO into NO3- instead of NO2, yet the selectivity of products remains challenging. Here, such a scenario could be realized by tailoring the exposure of Lewis acid sites on the surface of ZrO2, aiming to precisely regulate the ROS evolution process for the selective oxidation of NO into NO3-. As evidenced by highly combined experimental characterizations and density functional theory (DFT) simulations, Lewis acid sites serving as electron acceptors could induce itinerant electron redistribution, charge-carrier transfer, and further oxidation of •O2-, which promotes the oriented formation of 1O2. As a result, monoclinic ZrO2 with more Lewis acid sites exhibited an outstanding NO conversion efficiency (56.33%) and extremely low NO2 selectivity (5.04%). The ROS-based reaction process and promotion mechanism of photocatalytic performance have been revealed on the basis of ESR analysis, ROS-quenching experiments, and in situ ROS-quenching DRIFTS. This work could provide a critical view toward oriented ROS formation and advance a unique mechanism of selective NO oxidation into NO3-.


Subject(s)
Lewis Acids , Nitrogen Dioxide , Reactive Oxygen Species , Oxidation-Reduction , Oxidants
13.
Children (Basel) ; 10(7)2023 Jul 22.
Article in English | MEDLINE | ID: mdl-37508757

ABSTRACT

Gut microbiome development during early life has significant long-term effects on health later in life. The first-pass meconium is not sterile, and it is important to know the initial founder of the subsequent gut microbiome. However, there is limited data on the microbiota profile of the first-pass meconium in healthy neonates. To determine the early gut microbiota profile, we analyzed 39 samples of the first-pass meconium from healthy neonates using 16S rRNA sequencing. Our results showed a similar profile of the microbiota composition in the first-pass meconium samples. Pseudomonas was the most abundant genus in most samples. The evenness of the microbial communities in the first-pass meconium was extremely poor, and the average Shannon diversity index was 1.31. An analysis of the relationship between perinatal characteristics and the meconium microbiome revealed that primigravidae babies had a significantly higher Shannon diversity index (p = 0.041), and the Bacteroidales order was a biomarker for the first-pass meconium of these neonates. The Shannon diversity index was not affected by the mode of delivery, maternal intrapartum antibiotic treatment, prolonged rupture of membranes, or birth weight. Our study extends previous research with further characterization of the gut microbiome in very early life.

14.
IEEE Trans Nanobioscience ; 22(4): 967-977, 2023 10.
Article in English | MEDLINE | ID: mdl-37159315

ABSTRACT

In this article, a set of abstract chemical reactions has been employed to construct a novel nonlinear biomolecular controller, i.e, the Brink controller (BC) with direct positive autoregulation (DPAR) (namely BC-DPAR controller). In comparison to dual rail representation-based controllers such as the quasi sliding mode (QSM) controller, the BC-DPAR controller directly reduces the number of CRNs required for realizing an ultrasensitive input-output response because it does not involve the subtraction module, reducing the complexity of DNA implementations. Then, the action mechanism and steady-state condition constraints of two nonlinear controllers, BC-DPAR controller and QSM controller, are investigated further. Considering the mapping relationship between CRNs and DNA implementation, a CRNs-based enzymatic reaction process with delay is constructed, and a DNA strand displacement (DSD) scheme representing time delay is proposed. The BC-DPAR controller, when compared to the QSM controller, can reduce the number of abstract chemical reactions and DSD reactions required by 33.3% and 31.8%, respectively. Finally, an enzymatic reaction scheme with BC-DPAR controller is designed using DSD reactions. According to the findings, the enzymatic reaction process's output substance can approach the target level at a quasi-steady state in both delay-free and non-zero delay conditions, but the target level can only be achieved during a finite-time period, mainly due to the fuel stand depletion.


Subject(s)
DNA , Enzymes , DNA/chemistry , Enzymes/classification
16.
Int J Mol Sci ; 24(5)2023 Feb 24.
Article in English | MEDLINE | ID: mdl-36901900

ABSTRACT

Aplastic anemia (AA), a rare but potentially life-threatening disease, is a paradigm of bone marrow failure syndromes characterized by pancytopenia in the peripheral blood and hypocellularity in the bone marrow. The pathophysiology of acquired idiopathic AA is quite complex. Mesenchymal stem cells (MSCs), an important component of the bone marrow, are crucial in providing the specialized microenvironment for hematopoiesis. MSC dysfunction may result in an insufficient bone marrow and may be associated with the development of AA. In this comprehensive review, we summarized the current understanding about the involvement of MSCs in the pathogenesis of acquired idiopathic AA, along with the clinical application of MSCs for patients with the disease. The pathophysiology of AA, the major properties of MSCs, and results of MSC therapy in preclinical animal models of AA are also described. Several important issues regarding the clinical use of MSCs are discussed finally. With evolving knowledge from basic studies and clinical applications, we anticipate that more patients with the disease can benefit from the therapeutic effects of MSCs in the near future.


Subject(s)
Anemia, Aplastic , Mesenchymal Stem Cells , Pancytopenia , Animals , Anemia, Aplastic/pathology , Bone Marrow/pathology , Mesenchymal Stem Cells/physiology
17.
J Biol Chem ; 299(4): 103052, 2023 04.
Article in English | MEDLINE | ID: mdl-36813236

ABSTRACT

Phytoplasmas are insect-borne bacterial pathogens capable of secreting effectors into host cells and interfering with host plant defense response processes. Previous studies have found that the Candidatus Phytoplasma tritici effector SWP12 binds to and destabilizes the wheat transcription factor TaWRKY74, increasing wheat susceptibility to phytoplasmas. Here, we used a Nicotiana benthamiana transient expression system to identify two key functional sites of SWP12 and screened a series of truncated mutants and amino acid substitution mutants to determine whether they inhibit Bax-induced cell death. Using a subcellular localization assay and online structure analysis websites, we found that structure rather than intracellular localization probably affects the function of SWP12. D33A and P85H are two inactive substitution mutants, neither of which interacts with TaWRKY74, and P85H does not inhibit Bax-induced cell death, suppress flg22-triggered reactive oxygen species (ROS) bursts, degrade TaWRKY74, or promote phytoplasma accumulation. D33A can weakly suppress Bax-induced cell death and flg22-triggered ROS bursts and degrade a portion of TaWRKY74 and weakly promote phytoplasma accumulation. S53L, CPP, and EPWB are three SWP12 homolog proteins from other phytoplasmas. Sequence analysis revealed that D33 was conserved in these proteins, and they exhibited the same polarity at P85. Transient expression in N. benthamiana showed that these proteins could inhibit Bax-induced cell death and suppress ROS bursts. Our findings clarified that P85 and D33 of SWP12 play critical and minor roles, respectively, in suppressing the plant defense response and that they play a preliminary role in determining the functions of homologous proteins.


Subject(s)
Phytoplasma , Phytoplasma/chemistry , Phytoplasma/metabolism , Bacterial Proteins/metabolism , Amino Acids/metabolism , Reactive Oxygen Species/metabolism , bcl-2-Associated X Protein/metabolism , Plants/metabolism , Plant Diseases/microbiology
18.
J Colloid Interface Sci ; 630(Pt B): 290-300, 2023 Jan 15.
Article in English | MEDLINE | ID: mdl-36327732

ABSTRACT

Atomically dispersed active sites can effectively enhance the catalytic activity, but the synthesis of highly dispersed single-atom active sites remains challenging. Herein, we report for the fabrication of single-atom Ni on g-C3N4 (CN) catalysts for photocatalytic CO2 reduction reaction (CO2RR) using a high-energy ball milling method. The uniformly loaded single-atomic Ni on the surface of the substrate suggests the improvement of synthetic methods. After optimizing the Ni loading, the photocatalyst containing 0.5 at% (0.32 wt%) single-atomic Ni (Ni/CN-0.5) exhibited the highest CO2 reduction performance (∼19.9 µmol·g-1·h-1) without any co-catalyst or sacrificial agent. As visualized by aberration-corrected high-angle annular darkfield scanning transmission electron microscopy (AC HAADF-STEM), the Ni atoms in the Ni/CN-0.5 photocatalyst are most uniformly dispersed for different loadings (0.1, 0.3, 0.5, 0.7, 1.0, 3.0 and 5.0 at%). These results suggest that the uniformity of the single-atom active sites plays a decisive role rather than the loading amount in the highly enhanced performance. This work provides insight into the design of photocatalysts with highly dispersed single-atom catalytic active sites for enhancing activity.

19.
Sci Bull (Beijing) ; 67(11): 1137-1144, 2022 Jun 15.
Article in English | MEDLINE | ID: mdl-36545980

ABSTRACT

Dynamic defects on halide perovskite materials, caused by ion dissociation and migration under light illumination, typically result in undesirable energy dissipation and limited energy conversion efficiency. However, in this work, we demonstrated that dynamic halogen defects generated by the same process in bismuth oxyhalide (Bi5O7Cl) materials can act as active sites to promote charge separation and photocatalytic efficiency. Mechanistic studies and density functional theory calculations revealed that dynamic Cl defects affected the electronic structure of Bi5O7Cl and photocatalytic CO2 reduction process. As active sites, these defects promoted charge transfer, leading to the activation of adsorbed CO2 molecules and reduction of the energy barrier of the rate-determining step. Thus, CO2 was spontaneously converted into COOH- intermediate and finally reduced to CO with a high efficiency of 108.60 µmol g-1 and selectivity of 100% after 4-h of CO2 photoreduction. This work is highly instructive and valuable to the exploration of dynamic defects on halide-containing materials applied in solar energy conversion.

20.
Research (Wash D C) ; 2022: 9818792, 2022.
Article in English | MEDLINE | ID: mdl-36320637

ABSTRACT

Surface defects with abundant localized electrons on bismuth oxyhalide catalysts are proved to have the capability to capture and activate CO2. However, bismuth oxyhalide materials are susceptible to photocorrosion, making the surface defects easily deactivated and therefore losing their function as active sites. Construction of deactivation-resistant surface defects on catalyst is essential for stable CO2 photoreduction, but is a universal challenge. In this work, the Bi5O7I nanotubes with surface tensile strain are synthesized, which are favorable for the visible light-induced dynamic I defects generation. The CO2 molecules absorbed on I defects are constantly reduced by the incoming photogenerated electrons from I-deficient Bi5O7I nanotubes and the successive protonation of CO2 molecules is thus highly promoted, realizing the selective CO2 conversion process via the route of CO2-COOH--CO. The efficient and stable photoreduction of CO2 into CO with 100% selectivity can be achieved even under visible light (λ >420 nm) irradiation benefited from the dynamic I defects as active sites. The results presented herein demonstrate the unique action mechanism of light-induced dynamic defects during CO2 photoreduction process and provide a new strategy into rational design of deactivation-resistant catalysts for selective CO2 photoreduction.

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