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1.
Commun Biol ; 7(1): 255, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429435

RESUMO

Nicotinamide phosphoribosyltransferase (NAMPT) plays an important role in the biosynthesis of nicotinamide adenine dinucleotide (NAD+) via the nicotinamide (NAM) salvage pathway. While the structural biochemistry of eukaryote NAMPT has been well studied, the catalysis mechanism of prokaryote NAMPT at the molecular level remains largely unclear. Here, we demonstrated the NAMPT-mediated salvage pathway is functional in the Gram-negative phytopathogenic bacterium Xanthomonas campestris pv. campestris (Xcc) for the synthesis of NAD+, and the enzyme activity of NAMPT in this bacterium is significantly higher than that of human NAMPT in vitro. Our structural analyses of Xcc NAMPT, both in isolation and in complex with either the substrate NAM or the product nicotinamide mononucleotide (NMN), uncovered significant details of substrate recognition. Specifically, we revealed the presence of a NAM binding tunnel that connects the active site, and this tunnel is essential for both catalysis and inhibitor binding. We further demonstrated that NAM binding in the tunnel has a positive cooperative effect with NAM binding in the catalytic site. Additionally, we discovered that phosphorylation of the His residue at position 229 enhances the substrate binding affinity of Xcc NAMPT and is important for its catalytic activity. This work reveals the importance of NAMPT in bacterial NAD+ synthesis and provides insights into the substrate recognition and the catalytic mechanism of bacterial type II phosphoribosyltransferases.


Assuntos
Niacinamida , Xanthomonas campestris , Humanos , Niacinamida/metabolismo , NAD/metabolismo , Mononucleotídeo de Nicotinamida/metabolismo , Mononucleotídeo de Nicotinamida/farmacologia , Xanthomonas campestris/metabolismo , Nicotinamida Fosforribosiltransferase/química , Nicotinamida Fosforribosiltransferase/metabolismo , Fosforilação
2.
Small ; : e2311978, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38361184

RESUMO

Developing efficient and stable halide perovskite-based photocatalysts for highly selectivity reduction CO2 to valuable fuels remains a significant challenge due to their intrinsic instability. Herein, a novel heterostructure featuring 2D Cs3 Sb2 I9 nanosheets on a 3D flower-like mesoporous NiTiO3 framework using a top-down stepwise membrane fabrication technique is constructed. The unique bilayer heterostructure formed on the 3D mesoporous framework endowed NiTiO3 /Cs3 Sb2 I9 with sufficient and close interface contact, minimizing charge transport distance, and effectively promoting the charge transfer at the interface, thus improving the reaction efficiency of the catalyst surface. As revealed by characterization and calculation, the coupling of Cs3 Sb2 I9 with NiTiO3 facilitates the hydrogenation process during catalytic, directing reaction intermediates toward highly selective CH4 production. Furthermore, the van der Waals forces inherent in the 3D/2D heterostructure with face-to-face contact provide superior stability, ensuring the efficient realization of photocatalytic CO2 reduction to CH4 . Consequently, the optimized 3D/2D NiTiO3 /Cs3 Sb2 I9 heterostructure demonstrates an impressive CH4 yield of 43.4 µmol g-1  h-1 with a selectivity of up to 88.6%, surpassing most reported perovskite-based photocatalysts to date. This investigation contributes to overcoming the challenges of commercializing perovskite-based photocatalysts and paves the way for the development of sustainable and efficient CO2 conversion technologies.

3.
Zhongguo Dang Dai Er Ke Za Zhi ; 25(10): 1028-1033, 2023 Oct 15.
Artigo em Chinês | MEDLINE | ID: mdl-37905759

RESUMO

OBJECTIVES: To investigate the efficacy and required indicators of Children Neuropsychological and Behavioral Scale-Revision 2016 (CNBS-R2016) in the differential diagnosis of autism spectrum disorder (ASD) and global developmental delay (GDD). METHODS: A total of 277 children with ASD and 415 children with GDD, aged 18-48 months, were enrolled as subjects. CNBS-R2016 was used to assess the developmental levels of six domains, i.e., gross motor, fine motor, adaptive ability, language, social behavior, and warning behavior, and a total of 13 indicators on intelligence age and developmental quotient (DQ) were obtained as the input features. Five commonly used machine learning classifiers were used for training to calculate the classification accuracy, sensitivity, and specificity of each classifier. RESULTS: DQ of warning behavior was selected as the first feature in all five classifiers, and the use of this indicator alone had a classification accuracy of 78.90%. When the DQ of warning behavior was used in combination with the intelligence age of warning behavior, gross motor, and language, it had the highest classification accuracy of 86.71%. CONCLUSIONS: Machine learning combined with CNBS-R2016 can effectively distinguish children with ASD from those with GDD. The DQ of warning behavior plays an important role in machine learning, and its combination with other features can improve classification accuracy, providing a basis for the efficient and accurate differential diagnosis of ASD and GDD in clinical practice.


Assuntos
Transtorno do Espectro Autista , Criança , Humanos , Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/psicologia , Diagnóstico Diferencial , Aprendizado de Máquina , Comportamento Social
4.
Biology (Basel) ; 12(8)2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37626960

RESUMO

Despite the growing knowledge concerning allelopathic interference with barnyard grass, little is understood regarding the competitive physiological mechanisms of the interaction between allelopathic rice and herbicide-resistant barnyard grass. A hydroponic system was employed to investigate the root morphological traits and different phytohormonal changes in allelopathic and non-allelopathic rice cultivars when co-planted with quinclorac-resistant and -susceptible barnyard grass, respectively. The results show that shoot and root biomass were greater in PI. Barnyard grass stress induced an increase in shoot and root biomass in PI at 7 and 14 days of co-culturing rice and barnyard grass. Especially under the stress of quinclorac-resistant barnyard grass, the shoot biomass of PI increased by 23% and 68%, respectively, and the root biomass increased by 37% and 34%, respectively. In terms of root morphology, PI exhibited a significantly higher fine-root length, in root diameters of <0.5 mm, a greater number of root tips, and longer root tips compared to LE. The response to quinclorac-resistant barnyard grass stress was consistent in terms of the SA and JA content. The obvious accumulation of SA and JA was observed in two rice cultivars under quinclorac-resistant barnyard grass stress, with greater amounts of SA and JA in PI. The significant decrease in auxin (IAA) and abscisic acid (ABA) content in rice was detected from 7 to 14 days under co-culture stress. Additionally, highly significant and positive correlations were found between SA and JA content, and the number of root tips and root tip length at root diameters of 0-0.5 mm in rice.

5.
J Colloid Interface Sci ; 629(Pt A): 981-993, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36152622

RESUMO

It was well recognized that the penetrated electromagnetic (EM) wave could be dissipated by means of magnetic loss, polarization loss and conduction loss. In order to improve their loss capacities and take full advantage of flower-like geometrical morphology, in this study, we proposed a simple route for the production of flower-like core@shell structure NiO/Ni@C microspheres through the carbon thermal reaction using NiO microflowers as precursor. The obtained results revealed that our proposed strategy successfully synthesized the core@shell structure magnetic carbon-based multicomponent nanocomposites without destroying the geometrical morphology of precursor. By regulating the annealing temperature, the as-prepared NiO/Ni@C microspheres with different contents of Ni and degrees of graphitization could be selectively synthesized, which effectively boosted their magnetic loss, polarization loss and conduction loss capabilities. Therefore, the elaborately designed NiO/Ni@C microspheres displayed the superior microwave absorption performances including strong absorption capability, broad absorption bandwidth and thin matching thicknesses compared to the NiO precursor. In summary, our findings not only provided a simple route to design and synthesize flower-like core@shell structure magnetic carbon-based nanocomposites as novel microwave absorbers, but also presented an effective strategy to comprehensively improve their loss capacities.

6.
Crit Rev Food Sci Nutr ; : 1-13, 2022 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-36530054

RESUMO

Citrus peel, as an effective component of citrus by-products, contains a large number of natural active components, including pectin, vitamins, dietary fiber, essential oil, phenolic compounds, flavonoids, and so on. With the development of the circular economy, citrus peel has attracted extensive concern in the food industry. The exploitation of citrus peel would assist in excavating potential properties and alleviating the environmental burden. Polymethoxyflavones (PMFs) exist almost in citrus peel, which have remarkable biological activities including antioxidant, anti-inflammatory, anti-cancer, and anti-obesity. Therefore, PMFs from citrus peel have the potential to develop as dietary supplements in the near future. Collectively, it is essential to take action to optimize the extraction conditions of PMFs and make the most of the extracts. This review mainly compiles several extraction methods and bioactivities of PMFs from citrus peel and introduces different applications including food processing, pharmaceutical industry, and plant rhizosphere to develop better utilization of citrus PMFs.


Polymethoxyflavones (PMFs) represent sustainable bioactive compounds that profit for circular economy.Valorization of citrus peel PMFs will bring value-added environmental benefits.Novel techniques improve property and extraction efficiency of PMFs.PMFs obtained from citrus peel could be applied to tea or bakery food processing and pharmaceutical industry.

7.
Crit Rev Food Sci Nutr ; : 1-12, 2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36300845

RESUMO

Microorganisms in food do harms to human. They can cause serious adverse reactions and sometimes even death. So it is an urgent matter to find an effective method to control them. The research of intelligent- biosensor packaging is in the ascendant in recent years, which is mainly promoted by reflecting on food safety and reducing resource waste. Intelligent biosensor-packaging is an instant and efficient intelligent packaging technology, which can directly and scientifically manifest the quality of food without complex operation. In this review, the purposes of providing relevant information on intelligent biosensor-packaging are reviewed, such as types of biosensors for monitoring foodborne microorganism, the suitable material for intelligent biosensor-packaging and design and fabrication of intelligent biosensor-packaging. The potential of intelligent biosensor-packaging in the detection of foodborne microorganisms is emphasized. The challenges and directions of the intelligent biosensor-packaging in the detection of foodborne pathogens are discussed. With the development of science and technology in the future, the intelligent biosensor-packaging should be commercialized in a real sense. And it is expected that commercial products can be manufactured in the future, which will provide a far-reaching approach in food safety and food prevention. HighlightsSeveral biosensors are suitable for the detection of food microorganisms.Plastic polymer is an excellent choice for the construction of intelligent biosensor packaging.Design and fabrication can lay the foundation for intelligent-biosensor packaging.Intelligent biosensor-packaging can realize fast and real-time detection of microorganisms in food.

8.
J Gastroenterol Hepatol ; 37(11): 2060-2066, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36068945

RESUMO

BACKGROUND AND AIM: Considering the limitation of varying acid suppression of proton pump inhibitors, this study was aimed to assess the efficacy, safety, and dose-effect relationship of keverprazan, a novel potassium-competitive acid blocker, in the treatment of duodenal ulcer (DU) compared with lansoprazole. METHODS: A randomized, double-blind, double-dummy, multicenter, low-dose, high-dose, and positive-drug parallel-controlled study was conducted to verify the non-inferiority of keverprazan (20 or 30 mg) to lansoprazole of 30 mg once daily for 4 to 6 weeks and dose-effect relationship of keverprazan in the treatment of patients with active DU confirmed by endoscopy. RESULTS: Of the 180 subjects randomized, including 55 cases in the keverprazan_20 mg group, 61 cases in the keverprazan_30 mg group, and 64 cases in the lansoprazole_30 mg group, 168 subjects (93.33%) completed the study. The proportions of healed DU subjects in the keverprazan_20 mg, keverprazan_30 mg, and lansoprazole_30 mg groups were respectively 87.27%, 90.16%, and 79.69% at week 4 (P = 0.4595) and were respectively 96.36%, 98.36%, and 92.19% at week 6 (P = 0.2577). The incidence of adverse events in the keverprazan_20 mg group was lower than that in the lansoprazole_30 mg (P = 0.0285) and keverprazan_30 mg groups (P = 0.0398). CONCLUSIONS: Keverprazan was effective and non-inferior to lansoprazole in healing DU. Based on the comparable efficacy and safety data, keverprazan of 20 mg once daily is recommended for the follow-up study of acid-related disorders. (Trial registration number: ChiCTR2100043455.).


Assuntos
Antiulcerosos , Úlcera Duodenal , Humanos , Úlcera Duodenal/tratamento farmacológico , Úlcera Duodenal/induzido quimicamente , Antiulcerosos/uso terapêutico , Seguimentos , Lansoprazol/efeitos adversos , Inibidores da Bomba de Prótons/efeitos adversos , Método Duplo-Cego , 2-Piridinilmetilsulfinilbenzimidazóis/efeitos adversos
9.
Nanomaterials (Basel) ; 12(16)2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-36014689

RESUMO

Li-ion batteries (LIBs) and Na-ion batteries (SIBs) are deemed green and efficient electrochemical energy storage and generation devices; meanwhile, acquiring a competent anode remains a serious challenge. Herein, the density-functional theory (DFT) was employed to investigate the performance of V4C3 MXene as an anode for LIBs and SIBs. The results predict the outstanding electrical conductivity when Li/Na is loaded on V4C3. Both Li2xV4C3 and Na2xV4C3 (x = 0.125, 0.5, 1, 1.5, and 2) showed expected low-average open-circuit voltages of 0.38 V and 0.14 V, respectively, along with a good Li/Na storage capacity of (223 mAhg-1) and a good cycling performance. Furthermore, there was a low diffusion barrier of 0.048 eV for Li0.0625V4C3 and 0.023 eV for Na0.0625V4C3, implying the prompt intercalation/extraction of Li/Na. Based on the findings of the current study, V4C3-based materials may be utilized as an anode for Li/Na-ion batteries in future applications.

10.
J Colloid Interface Sci ; 624: 204-218, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35660889

RESUMO

Interfacial polarization and geometrical morphology play a significant role in the attenuation of electromagnetic (EM) wave. Herein, the two-dimensional (2D)/2D heterojunction with flower-like geometrical morphology is proposed and produced, which may simultaneously provide a large contact area for achieving strong interfacial polarization and activates more sites for the possible multiple EM wave reflection and scattering. By adopting a simple two-step hydrothermal method, MoSe2/MoS2and MoS2/MoSe2 inner and outer-interchangeable heterojunctions consisting of 2D MoSe2 and MoS2 nanosheets with flower-like geometrical morphology were successfully synthesized. The results revealed that the hydrothermal temperatures significantly impacted the flower-like geometrical morphology and MoS2 content. By optimizing the microstructures, the designed MoSe2/MoS2 and MoS2/MoSe2 heterojunctions presented enhanced comprehensive EM wave absorption properties (EMWAPs), possessing strong absorption capability, wide absorption bandwidth and thin matching thicknesses. Generally, this work demonstrates that the optimized EMWAPs of designed heterojunctions mainly originate from the special interfaces and morphology configuration, which also paves a new way for the designing and synthesis of transition metal dichalcogenides-based heterojunction as a novel and desirable candidate for high-performance microwave absorbers.

11.
Plants (Basel) ; 11(12)2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35736742

RESUMO

Although barnyardgrass (Echinochloa crus-galli L.) is more competitive than rice (Oryza sativa L.) in the aboveground part, little is known about whether barnyardgrass is still competitive in recruiting endophytes and the root microbiota composition variation of rice under the barnyardgrass stress. Here, by detailed temporal characterization of root-associated microbiomes of rice plants during co-planted barnyardgrass stress and a comparison with the microbiomes of unplanted soil, we found that the bacterial community diversity of rice was dramatically higher while the fungal community richness was significantly lower than that of barnyardgrass at BBCH 45 and 57. More importantly, rice recruited more endophytic bacteria at BBCH 45 and 57, and more endophytic fungi at BBCH 17, 24, 37 to aginst the biotic stress from barnyardgrass. Principal coordinates analysis (PCoA) showed that rice and barnyardgrass had different community compositions of endophytic bacteria and fungi in roots. The PICRUSt predictive analysis indicated that majority of metabolic pathways of bacteria were overrepresented in barnyardgrass. However, eleven pathways were significantly presented in rice. In addition, rice and barnyardgrass harbored different fungal trophic modes using FUNGuild analysis. A negative correlation between bacteria and fungi in rice and barnyardgrass roots was found via network analysis. Actinobacteria was the vital bacteria in rice, while Proteobacteria dominated in barnyardgrass, and Ascomycota was the vital fungi in each species. These findings provided data and a theoretical basis for the in-depth understanding of the competition of barnyardgrass and endophytes and have implications relevant to weed prevention and control strategies using root microbiota.

12.
BMC Plant Biol ; 22(1): 247, 2022 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-35585486

RESUMO

BACKGROUND: Sugarcane mosaic disease (SMD) is a major viral disease of sugarcane (Saccharum spp.) worldwide. Sorghum mosaic virus (SrMV) is the dominant pathogen of SMD in the sugarcane planting areas of China. There is no report on miRNAs and their regulatory networks in sugarcane response to SrMV infection. RESULTS: In this study, small RNA sequencing (sRNA-seq) of samples from the leaves of SMD-susceptible variety ROC22 and -resistant variety FN39 infected by SrMV was performed. A total of 132 mature miRNAs (55 known miRNAs and 77 novel miRNAs) corresponding to 1,037 target genes were identified. After the SrMV attack, there were 30 differentially expressed miRNAs (17 up-regulated and 13 down-regulated) in FN39 and 19 in ROC22 (16 up-regulated and 3 down-regulated). Besides, there were 18 and 7 variety-specific differentially expressed miRNAs for FN39 and ROC22, respectively. KEGG enrichment analysis showed that the differentially expressed miRNAs targeted genes involved in several disease resistance-related pathways, such as mRNA surveillance, plant pathway interaction, sulfur metabolism, and regulation of autophagy. The reliability of sequencing data, and the expression patterns / regulation relationships between the selected differentially expressed miRNAs and their target genes in ROC22 and FN39 were confirmed by quantitative real-time PCR. A regulatory network diagram of differentially expressed miRNAs and their predicted target genes in sugarcane response to SrMV infection was sketched. In addition, precursor sequences of three candidate differentially expressed novel miRNAs (nov_3741, nov_22650 and nov_40875) were cloned from the ROC22 leaf infected by SrMV. Transient overexpression demonstrated that they could induce the accumulation of hydrogen peroxide and the expression level of hypersensitive response marker genes, salicylic acid-responsive genes and ethylene synthesis-depended genes in Nicotiana benthamiana. It is thus speculated that these three miRNAs may be involved in regulating the early immune response of sugarcane plants following SrMV infection. CONCLUSIONS: This study lays a foundation for revealing the miRNA regulation mechanism in the interaction of sugarcane and SrMV, and also provides a resource for miRNAs and their predicted target genes for SrMV resistance improvement in sugarcane.


Assuntos
MicroRNAs , Vírus do Mosaico , Potyvirus , Saccharum , Sorghum , Grão Comestível/genética , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , MicroRNAs/metabolismo , Vírus do Mosaico/genética , Vírus do Mosaico/metabolismo , Doenças das Plantas/genética , Reprodutibilidade dos Testes , Saccharum/metabolismo , Sorghum/genética , Sorghum/metabolismo
13.
Front Cardiovasc Med ; 9: 825561, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35479265

RESUMO

Acute pulmonary embolism (acPE) is a severe disease that is often misdiagnosed as it is difficult to detect quickly and accurately. In this study, a novel electrocardiogram (ECG) model was used to estimate the probability of acPE rapidly via analysis of ECG characteristics. A total of 327 patients with acPE who were diagnosed at the Sichuan Provincial People's Hospital (SPPH) between 2018 and 2021 were retrospectively studied. A total of 331 patients were randomly selected as the control group, which included patients hospitalized during the same time period. The control group included patients who presented with characteristic symptoms of acPE, but this diagnosis was ruled out following further diagnostic testing. This study compared the diagnostic value of the ECG model with those of another ECG scoring model (Daniel-ECG score) and the most common prediction models (Wells score and Geneva score). This study established an ECG-predictive model using analysis of the ECG abnormalities in patients with acPE. The final ECG model included certain novel ECG signs that had not been incorporated in the previous ECG score of the patients, and thus, compared to the previous ECG score, exhibited a more favorable area under the receiver operating characteristic curve (AUC) value (0.8741). The model developed in this study was named the SPPH-ECG model. Furthermore, this study compared the SPPH-ECG model with Daniel-ECG score, Wells score, and Geneva score, and the SPPH-ECG model was demonstrated to exhibit a superior AUC value (0.8741), sensitivity (79.08%), negative predictive value (79.52%), and test accuracy (79.42%), while the Geneva score presented superior specificity (100%) and positive predictive value (100%) compared with the SPPH-ECG model. In conclusion, the SPPH-ECG model may play a role in ruling out acPE in patients during diagnostic testing and diagnose acPE rapidly and accurately in combination with the Geneva scoring system.

14.
ACS Appl Mater Interfaces ; 14(18): 20896-20906, 2022 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-35481359

RESUMO

Carbon materials with well-dispersed SnOx particles exhibit excellent lithium-storage performance. However, the volume change of SnOx and the weak interaction between SnOx and carbon induce an unsteady SnOx-C interface during the lithiation/delithiation process. This phenomenon results in enhanced charge transfer resistance and reduced electrical contact of active materials, which leads to low reversibility of tin oxidation, restricted capacity, sluggish kinetics, structural deterioration, and rapid capacity decay. Herein, tin oxide/carbon composites with a metaphosphate-bridged interface are synthesized to construct a robust interfacial contact between tin oxides and carbon. The metaphosphate group functions as a bridge between SnOx and carbon and results in excellent electrochemical stability during the charge/discharge process, which is favorable for electrode structural integrity. The formation of the metaphosphate-bridged interface provides a steady transport channel for e-/Li+ and thus improves the reversibility of the conversion reaction. The enhanced charge transfer and interaction can also boost the charge transfer between SnOx and carbon, which leads to higher SnOx utilization. Thus, the prepared P-SnOx/C anode exhibits enhanced lithium-storage performance in terms of specific capacity, cycling stability, and rate performance.

15.
Comput Urban Sci ; 2(1): 21, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37096207

RESUMO

A restless and dynamic intellectual landscape has taken hold in the field of spatial social network studies, given the increasingly attention towards fine-scale human dynamics in this urbanizing and mobile world. The measuring parameters of such dramatic growth of the literature include scientific outputs, domain categories, major journals, countries, institutions, and frequently used keywords. The research in the field has been characterized by fast development of relevant scholarly articles and growing collaboration among and across institutions. The Journal of Economic Geography, Annals of the Association of American Geographers, and Urban Studies ranked first, second, and third, respectively, according to average citations. The United States, United Kingdom, and China were the countries that yielded the most published studies in the field. The number of international collaborative studies published in non-native English-speaking countries (such as France, Italy, and the Netherlands) were higher than native English-speaking countries. Wuhan University, the University of Oxford, and Harvard University were the universities that published the most in the field. "Twitter", "big data", "networks", "spatial analysis", and "social capital" have been the major keywords over the past 20 years. At the same time, the keywords such as "social media", "Twitter", "big data", "geography", "China", "human mobility", "machine learning", "GIS", "location-based social networks", "clustering", "data mining", and "location-based services" have attracted increasing attention in that same time frame, indicating the future research trends.

16.
J Colloid Interface Sci ; 608(Pt 3): 2387-2398, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34763891

RESUMO

Nanocomposites with a three-dimensional (3D) flower-like geometrical morphology were considered as excellent microwave absorbers (MAs) because of the numerous effective sites for the multiple reflections of electromagnetic (EM) wave. Herein, for optimizing the EM matching characteristic and taking full advantage of interface polarization, a strategy of magnetic modulation was proposed to further improve the EM wave absorption performances (EMWAPs) of MoS2-based nanocomposites. We adopted a simple hydrothermal route and a combined method of hydrothermal treatment/hydrogen reduction to synthesize core@shell CoFe2O4@MoS2 and CoFe@MoO2/MoS2 flower-like nanocomposites, respectively. The obtained results indicated that the hydrogen reduction effectively improved their magnetic properties and magnetic loss capabilities, and their 3D flower-like geometrical morphologies were well maintained during the hydrogen reduction process. The obtained core@shell CoFe@MoO2/MoS2 flower-like nanocomposites presented the extraordinary comprehensive EMWAPs including the optimal reflection loss value of -54.83 dB with the matching thicknesses (dm) value of 2.05 mm and effective absorption bandwidth value of 6.40 GHz with the dm value of 2.59 mm, which were evidently superior to the properties of CoFe2O4@MoS2. Therefore, the findings provided an effective pathway to further improve EMWAPs of MoS2-based core@shell nanocomposites and the as-prepared core@shell CoFe@MoO2/MoS2 flower-like nanocomposites could be utilized as the novel high-efficient MAs.

17.
J Colloid Interface Sci ; 605: 13-22, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34303922

RESUMO

Using previous models and theories to construct and develop high-efficient microwave absorbers (MAs) should be a strategic and effective ways to optimize the electromagnetic wave attenuation. Herein, the ultralow density and flexible graphene oxide foam (GOF) and reduced graphene oxide foam (RGOF)/MoS2 nanosheets were designed and fabricated by the method of chemical vapor deposition and hydrothermal reaction. The obtained GOF and RGOF/MoS2 samples exhibited very excellent microwave absorption properties while their densities were merely 0.0082 and 0.0084 g•cm-3, respectively. More importantly, benefiting from the excellent synergistic effect between RGOF and MoS2, the designed RGOF/MoS2 well inherited the combined advantages of GOF and MoS2 in terms of strong absorption abilities, broad absorption bandwidth and thin matching thicknesses. The values of minimum reflection loss and effective frequency bandwidth for RGOF/MoS2 sample could reach up to -62.92 dB with the matching thickness of 2.27 mm and 4.48 GHz with the matching thickness of 2.12 mm, which were very desirable for high-performance MAs. Moreover, the obtained results indicated that the microwave absorption properties of RGOF/MoS2 sample could be further optimized by regulating the MoS2 content. Therefore, a new and effective strategy was proposed to develop high efficiency MAs with ultra-lightweight, wide-band, thin thickness and strong absorption capabilities.

18.
J Colloid Interface Sci ; 606(Pt 2): 1128-1139, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34487933

RESUMO

Morphology optimization is an effective strategy to take full advantage of interface polarization for the improvement of electromagnetic wave attenuation capability. Herein, a general route was proposed to produce the flower-like core@shell structured MoS2-based nanocomposites through a simple hydrothermal process. Through the in-situ hydrothermal reaction between the Mo and S sources on the surface of CoNi nanoparticles, flower-like core@shell structured CoNi2S4/Co9S8@MoS2 nanocomposites could be successfully synthesized. By regulating the hydrothermal temperature, the flower-like geometrical morphology of samples could be effectively optimized, and the as-prepared sample (S2) synthesized at 200 °C displayed very excellent flower-like morphology compared to the samples (S1 and S3) obtained at 180 and 220 °C. Owing to the excellent interface polarization effect, the as-prepared S2 presented the evidently superior comprehensive microwave absorption properties in terms of strong aborption capability, wide absorption bandwidth and thin matching thicknesses compared to those of S1 and S3. The as-prepared core@shell structured CoNi2S4/Co9S8@MoS2 sample with very excellent flower-like morphology simultaneously displayed the minimal reflection loss of -50.61 dB with the matching thickness of 2.98 mm, and the effective absorption bandwidth of 8.40 GHz with the matching thickness of 2.36 mm. Therefore, we provided a general route for the production of flower-like core@shell structured MoS2-based nanocomposites, which could make the best of interface polarization to develop high-efficiency microwave absorbers.

19.
Zhongguo Dang Dai Er Ke Za Zhi ; 23(12): 1200-1207, 2021 Dec 15.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-34911601

RESUMO

OBJECTIVES: To assess the growth of preterm infants up to a corrected age of 24 months, and to understand the growth trend and pattern of preterm infants. METHODS: A preterm infant follow-up database was established based on the Internet Plus follow-up system. A total of 3 188 preterm infants who were born from April 2018 to April 2021 were enrolled. Their length, weight, and head circumference were recorded at birth and at the corrected ages of 1, 3, 6, 12, 18, and 24 months. The preterm infants were grouped by perinatal factors. The growth curves of these infants were plotted and compared with the International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH-21st) standard and World Health Organization (WHO) standard. RESULTS: The weight, length, and head circumference curves of each group of preterm infants grouped by various perinatal factors all rose rapidly within the corrected age of 6 months, but the growth rate slowed down after the corrected age of 6 months. Based on the actual age for the groups of preterm infants with different gestational ages (<28 weeks, 28-31+6 weeks, 32-33+6 weeks, and 34-36+6 weeks), the length curve gradually coincided with the WHO curve after the actual age of 9 months (P=0.082), while for the preterm infants with a gestational age of <32 weeks, the weight and head circumference curves were significantly lower than the WHO curves (P<0.001). Based on the corrected age, the physical growth curve of preterm infants with different gestational ages (<28 weeks, 28-31+6 weeks, 32-33+6 weeks, and 34-36+6 weeks) basically coincided with each other (P>0.05). For the infants with extremely low birth weight and the small-for-gestational-age infants, the length, weight, and head circumference curves were significantly lower than those of the INTERGROWTH-21st standard and the WHO standard (P<0.05). CONCLUSIONS: The physical growth rate of preterm infants is faster within the corrected age of 6 months, and the growth rate slows down after the corrected age of 6 months. Preterm infants with a smaller gestational age need longer time to catch up in weight and head circumference. More attention should be paid to the physical growth of extremely preterm infants, extremely low birth weight infants, and small-for-gestational-age infants.


Assuntos
Recém-Nascido Prematuro , Recém-Nascido Pequeno para a Idade Gestacional , Cefalometria , Pré-Escolar , Feminino , Idade Gestacional , Humanos , Lactente , Recém-Nascido de Peso Extremamente Baixo ao Nascer , Recém-Nascido , Gravidez
20.
ACS Omega ; 6(38): 24731-24738, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34604655

RESUMO

Developing high-efficiency and low-cost multifunctional electrocatalysts is the core of unitized regenerative fuel cells (URFC), yet it remains a great challenge. Here, by performing first-principles calculations, we report the atomic-level electrocatalytic activity mechanism of 3d, 4d, and 5d monoatomic transition metals (TM) bound to the 1T-MoS2 monolayer for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Their structural stabilities are evaluated via the formation energy, elastic constant, and molecular dynamics simulations. Compared with the Co-N4-C single atom catalyst (SAC), the resulting Pd@1T-MoS2 SAC exhibits better bifunctional catalytic activity, with OER overpotential as low as 0.43 V and an ORR overpotential of 0.40 V. The dual volcano plot demonstrates that the bifunctional OER and ORR activities of Pd@1T-MoS2 originate from the neither strong nor weak OH* adsorption and the suitable d-band center (-1.83 eV) of the Pd active center. In conjunction with the intrinsic activity of the 1T-MoS2 monolayer for hydrogen evolution reaction, the Pd@1T-MoS2 SAC is a competitive and promising trifunctional electrocatalyst for sustainable energy conversion and storage systems.

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