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1.
Food Chem ; 432: 137095, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-37657337

RESUMO

Currently, the effect of varieties on the flavor and stability of flaxseed milk remains unknown. Therefore, this study was conducted to investigate the effects of different varieties on the stability, sensory, and aromas of flaxseed milk. 51 volatile compounds were identified in flaxseed milk using Stir Bar Sorptive Extraction-Gas Chromatography-Olfactometry-Mass Spectrometry (SBSE-GC-O-MS). Among them, 1-octen-3-ol, 2-methoxy-4-vinylphenol, and 2,3,5-trimethylpyrazine contributed higher relative odor active values (ROAV), resulted in the fruity, roasted, sweet, and cucumber in flaxseed milk. Isovaleraldehyde (green notes) was not detected in XHZM. However, other compounds such as 1-nonanol (floral), γ-nonanolactone and γ-octanoic lactone (coconut milk) had higher concentrations, causing a better sensory evaluation. Additionally, its stability was relatively good. The orthogonal partial least-squares regression (OPLS) model and VIP values showed that eight compounds were responsible for the sensory differences from different varietals. The study provided references to selection and understanding flavor composition basis of flaxseed milk.


Assuntos
Linho , Leite , Animais , Odorantes , Cromatografia Gasosa-Espectrometria de Massas , Doces
2.
Micromachines (Basel) ; 14(9)2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37763928

RESUMO

Laser polishing is an emerging efficient technique to remove surface asperity without polluting the environment. However, the insufficient understanding of the mechanism of laser polishing has limited its practical application in industry. In this study, a dual-beam laser polishing experiment was carried out to reduce the roughness of a primary Ti6Al4V sample, and the polishing mechanism was well studied using simulation analysis. The results showed that the surface roughness of the sample was efficiently reduced from an initial 10.96 µm to 1.421 µm using dual-beam laser processing. The simulation analysis regarding the evolution of material surface morphology and the flow behavior of the molten pool during laser the polishing process revealed that the capillary force attributed to surface tension was the main driving force for flattening the large curvature surface of the molten pool at the initial stage, whereas the thermocapillary force influenced from temperature gradient played the key role of eliminating the secondary roughness at the edge of the molten pool during the continuous wave laser polishing process. However, the effect of thermocapillary force can be ignored during the second processing stage in dual-beam laser polishing. The simulation result is well in agreement with the experimental result, indicating the accuracy of the mechanism for the dual-beam laser polishing process. In summary, this work reveals the effect of capillary force and thermocapillary force on molten pool flows during the dual-beam laser polishing processes. Moreover, it is also proved that the dual-beam laser polishing process can further reduce the surface roughness of a sample and obtain a smoother surface.

3.
Plants (Basel) ; 12(18)2023 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37765502

RESUMO

In higher plants, cuticular wax deposited on the surface of epidermal cells plays an important role in protecting the plant from biotic and abiotic stresses; however, the molecular mechanism of cuticular wax production is not completely understood. In this study, we identified a glossy green mutant (98-1030gl) from the glaucous cabbage inbred line 98-1030. Scanning electron microscopy indicated that the amount of leaf cuticular wax significantly decreased in 98-1030gl. Genetic analysis showed that the glossy green trait was controlled by a single recessive gene. Bulked segregant analysis coupled with whole genome sequencing revealed that the candidate gene for the glossy green trait was located at 13,860,000-25,070,000 bp (11.21 Mb) on Chromosome 5. Based on the resequencing data of two parents and the F2 population, insertion-deletion markers were developed and used to reduce the candidate mapping region. The candidate gene (Bol026949) was then mapped in a 50.97 kb interval. Bol026949 belongs to the Agenet/Tudor domain protein family, whose members are predicted to be involved in chromatin remodeling and RNA transcription. Sequence analysis showed that a single nucleotide polymorphism mutation (C → G) in the second exon of Bol026949 could result in the premature termination of its protein translation in 98-1030gl. Phylogenetic analysis showed that Bol026949 is relatively conserved in cruciferous plants. Transcriptome profiling indicated that Bol026949 might participate in cuticular wax production by regulating the transcript levels of genes involved in the post-translational cellular process and phytohormone signaling. Our findings provide an important clue for dissecting the regulatory mechanisms of cuticular wax production in cruciferous crops.

4.
Sensors (Basel) ; 23(18)2023 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-37765839

RESUMO

This study investigates the utilization of a stepped wave frequency modulation jamming technique in radar systems. The objective is to enhance the effectiveness and robustness of false target jamming in the presence of linear frequency modulation (LFM) radars employing constant false alarm rate (CFAR) detection. The proposed method combines stepped frequency modulation with full pulse delay/sum repeat jamming to enhance resilience against uncertainties in target parameters. Theoretical analysis and simulation experiments are conducted to establish relationships between key jammer parameters, such as frequency slope and power compensation, and performance metrics, like false target distribution and CFAR masking. The results demonstrate that the proposed technique effectively maintains a dense distribution of false targets surrounding the protected target, even in the presence of uncertainties in position and signal-to-noise ratio. In comparison to existing methods, the utilization of stepped-waveform modulation enables improved control over target distribution and CFAR masking. Adaptive power allocation compensates for parameter errors, thereby enhancing robustness. Simulation results reveal that the proposed approach significantly reduces the probability of detecting the true target by over 95% under uncertain conditions, while previous methods experienced degradation. The integration of stepped waveforms optimizes false target jamming, thereby advancing electronic warfare capabilities in countering advanced radar threats. This study establishes design principles for resilient jamming architectures and supports enhanced survivability against radars employing pulse compression and CFAR detection. Moreover, the concepts proposed in this study have the potential for extension to emerging radar waveforms.

5.
Water Sci Technol ; 88(6): 1374-1393, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37768742

RESUMO

Pumped-storage power stations (PSPSs) have higher requirements for anti-seepage compared with regular power stations. As a result, investigating the seepage distributions of PSPSs is particularly important. However, existing researches remain limited in assessing engineering needs such as ensuring the efficiency of a power station. Taking the Qingyuan PSPS as a typical case, this study aims to investigate the large-scale seepage field distribution while exploring the efficiency of the anti-seepage system. Considering the geological characteristics and structural location, a 3D finite element model is established. Based on the continuous medium model while combined with seepage control measures, the change in leakage while the anti-seepage system failed is further assessed. It is concluded that the operation status of anti-seepage measures will have a certain impact on the leakage volumes of each part. Using a comprehensive assessment, anti-seepage measures can effectively prevent seepage. When failure occurs on anti-seepage curtains, the leakage volume at the corresponding position will show an obvious growth. In summary, the findings of this study highlight the significance of avoiding excessive leakage caused by anti-seepage structure failure, the effective operation of anti-seepage measures must be ensured. The abovementioned results can provide scientific support for the seepage optimization design of PSPSs.


Assuntos
Geologia , China
6.
Cell Biosci ; 13(1): 180, 2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37770976

RESUMO

BACKGROUND: Metastases within liver or the brain are the most common causes of mortality from lung cancer (LC). Predicting liver or brain metastases before having evidence from imaging of the tumors is challenging but important for early patient intervention. According to mounting evidence, exosomes circulating within blood may facilitate cancer spread by transporting certain proteins for target cells. METHODS: Using liquid chromatography-MS/MS, we investigated the plasma exosomes' proteomic profiles derived from 42 metastatic LC patients [16 solitary liver metastasis (LM), together with 26 solitary brain metastasis (BM)] and 25 local advanced (LA) lung cancer cases without metastasis, together with five healthy controls (HC), assessing the LM and BM pathogenesis and find potential novel organ-designated proteomic biomarkers. Using ELISA assay, we verified the expression levels of three plasma exosomal protein biomarkers in 110 LC patients, including 40 solitary LM, 32 solitary BM and 38 LA, and 25 HC. RESULTS: In total, 143 and 120 differentially expressed exosome-based proteins (DEEPs) were found to be dysregulated in LM and BM of lung cancer (LM-DEEPs, BM-DEEPs), compared for LA lung cancer samples, respectively. The bioinformatics analyses indicated the heterogeneity and homogeneity in LM-DEEPs and BM-DEEPs. They were primarily engaged within proteomic triggering cascade, ECM-receptor interaction, and the collagen-containing extracellular matrix. Regarding heterogeneity, LM-DEEPs primarily consisted of proteoglycans, lipoprotein, integrin, and heat shock protein, whereas the BM-DEEPs consisted of calcium-dependent/S100 proteins. Furthermore, small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC)-plasma-stemming exosome proteomics showed heterogeneity, which helped to explain some of the differences between SCLC and NSCLC's metastatic features. We also found that SELL and MUC5B could be used as diagnostic markers of BM, while APOH, CD81, and CCT5 could help diagnose LM in LC patients. Additionally, we demonstrated in a validation cohort that MUC5B and SELL could serve as biomarkers for diagnosing BM, and APOH could be a novel potential diagnostic biomarker of LM. CONCLUSION: We presented the comprehensive and comparative plasma-stemming exosomes' proteomic profiles from cases of LC who had isolated liver and brain metastases for the first time. We also suggested several possible biomarkers and pathogenic pathways that might be a great starting point for future research on LC metastasis.

7.
Water Sci Technol ; 88(5): 1178-1193, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37771221

RESUMO

Three-dimensional excitation-emission matrix fluorescence spectroscopy coupled with parallel factor analysis was adopted to investigate the characteristics of dissolved organic matter (DOM) components in water samples collected from the Tuojiang River Basin in Chengdu, including its main stream and tributaries. Four DOM components that matched with three fluorescence peaks were identified in the whole river basin and tributaries; while three components corresponding to four fluorescence peaks were identified in the main stream. In all cases, humic-like components accounted for high proportions of the DOM. Correlation analysis revealed the same sources for four components in the whole river basin and its tributaries, whereas two components had different sources in the main stream. Ultraviolet absorbance parameters (SUVA254, SR) and fluorescence parameters (BIX, HIX, FI, ß:α) indicated the dominant autochthonous sources of DOM in the whole river basin. Higher terrestrial inputs of DOM were observed in the tributaries than in the main stream. In the areas influenced by human activities (6#, 17#, 18#), the sources of DOM showed strong terrestrial characteristics and high degrees of humification and aromatization, as well as serious pollution. The results of this study have potentially far-reaching implications for environmental water management in the area.

8.
J Ultrasound Med ; 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37772628

RESUMO

OBJECTIVES: This study aimed to investigate the combined use of ultrasonography and clinical features for the differentiation of malignant peripheral nerve sheath tumors (MPNST) from benign peripheral nerve sheath tumors (BPNST) and to compare the efficacy of ultrasonography with that of magnetic resonance imaging (MRI). METHODS: This retrospective study included 28 MPNSTs and a control group of 57 BPNSTs. All patients underwent an ultrasound scan using the Logiq E9 (GE Health Care, Milwaukee, WI) or EPIQ7 equipment (Philips Medical System, Bothell, WA). A 3.0-T MRI machine (Ingenia; Philips Healthcare, Best, the Netherlands) was used for scanning, and conventional MRI was performed on different regions based on the patient's clinical situation. The following variables were evaluated: palpable mass, pain, nerve symptoms, maximum diameter, location, shape, boundary, encapsulation, echogenicity, echo homogeneity, presence of a cystic component, calcification, target sign, posterior echo, and intertumoral vascularity of the tumors. The diagnostic efficacy of ultrasonography and clinical factors was compared with that of MRI. Independent factors for predicting MPNST versus BPNST were also assessed. RESULTS: The parameters of location, shape, boundary, encapsulation, and vascularity were significantly different between MPNSTs and BPNSTs. Multiple logistic regression analysis showed that shape, boundary, and vascularity were independent predictors of MPNSTs. The sensitivity, specificity, and Youden index of the three clinical and ultrasound factors (shape, boundary, and vascularity) were 0.89, 0.81, and 0.69, respectively, whereas those of MRI were 0.71, 0.89, and 0.61, respectively. No significant differences in the area under the curve (AUC) of the three combined clinical and ultrasound factors and those of MRI were found (P > .05). CONCLUSIONS: MRI was useful in the differential diagnosis between MPNSTs and BPNSTs. However, the combination of clinical and ultrasound diagnoses can achieve the same effect as MRI, including shape, boundary, and vasculature.

9.
Nano Lett ; 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37772787

RESUMO

Two-dimensional (2D) transition metal carbides/nitrides (MXenes) are promising nanomaterials due to their remarkable mechanical and electrical properties. However, the out-of-plane mechanical properties of MXene under impact loading remain unclear. Here, particular impact-resistant fracture behaviors and energy dissipation mechanisms of MXene were systemically investigated via molecular dynamics (MD) simulation. Specifically, it was found that the specific penetration energy of MXene exceeds most conventional impact-resistant materials, such as aluminum and polycarbonate. Two kinds of novel energy dissipation mechanisms, including radial fracture and crushed fracture under different impact velocities, are revealed. In addition, the sandwiched atomic-layer structure of MXene can deflect cracks and restrain their propagation to some extent, enabling the cracked MXene to retain remarkable resistance. This work provides in-depth insights into the impact-resistance of MXene, laying a foundation for its future applications.

10.
ACS Appl Mater Interfaces ; 15(38): 45016-45025, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37702038

RESUMO

The manipulation of defect chemistry is crucial in the design of high-performance thermoelectric materials. Studies have demonstrated that alloying compounds within the I-V-VI2 family, such as AgSbTe2, NaSbTe2, etc., can effectively enhance the thermoelectric performance of SnTe by controlling the hole concentration and reducing the lattice thermal conductivity. In this paper, samples of SnTe alloyed with MnSb2Se4 were prepared, and the microstructure, electrical properties, and thermal properties were thoroughly investigated. Based on SEM and TEM analysis, it was observed that MnSb2Se4 can dissolve into SnTe during the preparation of the samples, which leads to the formation of various secondary phases with different compositions and point defects. Consequently, the lattice thermal conductivity is reduced to 0.44 W m-1 K-1 at 800 K, approaching the amorphous limit. Furthermore, the diffusion of the Mn and Sb elements leads to a significant improvement in the Seebeck coefficient through valence band convergence. The vacancy concentration in SnTe can also be modulated by alloying with MnSb2Se4. The findings indicated that MnSb2Se4 alloying can enhance the thermoelectric performance of SnTe through increasing the vacancy concentration, promoting valence band convergence, and introducing secondary phases. Consequently, a ZT value of 1.36 at 800 K for Sn1.03Te-5%MnSb2Se4 can be achieved.

11.
Eur J Obstet Gynecol Reprod Biol ; 289: 140-144, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37660509

RESUMO

We report a case of a fetus with 46,XX testicular disorder of sex development detected prenatally. This fetus was found abnormally due to non-invasive prenatal testing. Amniocentesis revealed SRY gene on the X chromosome of the fetus. The related literature was reviewed, and the advantages and limitations of various prenatal diagnostic techniques were discussed. The combination of non-invasive prenatal testing and various prenatal diagnostic techniques has enabled more fetuses with sex reversal to be detected.


Assuntos
Genes sry , Diagnóstico Pré-Natal , Feminino , Gravidez , Humanos , Amniocentese , Desenvolvimento Sexual , Feto
12.
Environ Sci Technol ; 57(37): 13887-13900, 2023 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-37667485

RESUMO

In this study, sequencing batch operation was successfully combined with a pilot-scale anaerobic biofilm-modified anaerobic/aerobic membrane bioreactor to achieve anaerobic ammonium oxidation (anammox) without inoculation of anammox aggregates for municipal wastewater treatment. Both total nitrogen and phosphorus removal efficiencies of the reactor reached up to 80% in the 250-day operation, with effluent concentrations of 4.95 mg-N/L and 0.48 mg-P/L. In situ enrichment of anammox bacteria with a maximum relative abundance of 7.86% was observed in the anaerobic biofilm, contributing to 18.81% of nitrogen removal, with denitrification being the primary removal pathway (38.41%). Denitrifying phosphorus removal (DPR) (40.54%) and aerobic phosphorus uptake (48.40%) played comparable roles in phosphorus removal. Metagenomic sequencing results showed that the biofilm contained significantly lower abundances of NO-reducing functional genes than the bulk sludge (p < 0.01), favoring anammox catabolism in the former. Interactions between the anammox bacteria and flanking community were dominated by cooperation behaviors (e.g., nitrite supply, amino acids/vitamins exchange) in the anaerobic biofilm community network. Moreover, the hydrolytic/fermentative bacteria and endogenous heterotrophic bacteria (Dechloromonas, Candidatus competibacter) were substantially enriched under sequencing batch operation, which could alleviate the inhibition of anammox bacteria by complex organics. Overall, this study provides a feasible and promising strategy for substantially enriching anammox bacteria and achieving partial mainstream anammox as well as DPR.


Assuntos
Oxidação Anaeróbia da Amônia , Biofilmes , Transporte Biológico , Reatores Biológicos , Fermentação
14.
Zhongguo Gu Shang ; 36(9): 901-4, 2023 Sep 25.
Artigo em Chinês | MEDLINE | ID: mdl-37735086

RESUMO

There are inconsistencies in treatment outcomes, measurement instruments, and criteria for assessing clinical effectiveness in studies related to distal radius fractures (DRF), resulting in potential biases and failing to provide high-quality clinical evidence. To address these challenges, international researchers have reached a consensus on developing the core outcome indicator set for distal radius fractures(COS-DRF). However, it's important to note that the existing COS-DRF framework could not reflect the unique characteristics of Traditional Chinese Medicine (TCM) treatment. Currently, there are no established standards for treatment outcomes and measurement instruments specific to TCM clinical research, nor has a COS-DRF been established for TCM clinical studies in China. In light of these gaps, our research team aims to construct a core set of treatment outcomes for TCM clinical research on distal radius fractures. This involves compiling a comprehensive list of treatment outcomes and measurement instruments, initially derived from a thorough literature review and expert consensus, which will then undergo further refinement and updates based on real-world clinical experiences, incorporating feedback from 2 to 3 rounds of expert consensus or Delphi questionnaire surveys. Our goal is to establish a COS-DRF or CMS-DRF that aligns with the principles and practices of TCM, and provide high-quality evidence for clinical practice.


Assuntos
População do Leste Asiático , Fraturas do Punho , Humanos , China , Consenso , Avaliação de Resultados em Cuidados de Saúde
15.
Int J Antimicrob Agents ; 62(5): 106962, 2023 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-37673355

RESUMO

INTRODUCTION: The rapid emergence of infections caused by multidrug-resistant Acinetobacter baumannii (A. baumannii) has posed a serious threat to global public health. It has therefore become important to obtain a deeper understanding of the mechanisms of multidrug resistance and pathogenesis of A. baumannii; however, there are still relatively few genetic engineering tools for this. Although A. baumannii possesses Type I-F CRISPR-Cas systems, they have not yet been used for genetic modifications. METHODS: A single plasmid-mediated native Type I-F CRISPR-Cas system for gene editing and gene regulation in A. baumannii was developed. The protospacer adjacent motif sequence was identified as 5'-NCC-3' by analysis of the CRISPR array. RESULTS: Through introduction of the RecAb homologous recombination system, the knockout efficiency of the oxyR gene significantly increased from 12.5% to 75.0% in A. baumannii. To investigate transcriptional inhibition by the Type I-F CRISPR system, the gene encoding its Cas2-3 nuclease was deleted and the native Type I-F Cascade effector was repurposed to regulate transcription of alcohol dehydrogenase gene adh4. The level of adh4 transcription was inhibited by up to 900-fold compared with the control. The Cascade transcriptional module was also successfully applied in a clinical Klebsiella pneumoniae isolate. CONCLUSION: This study proposed a tool for future exploration of the genetic characteristics of A. baumannii or other clinical strains.

16.
Bioresour Technol ; 388: 129781, 2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37730139

RESUMO

The lignin-based metal-organic framework (UIO-g-NL) was prepared by a Schiff base reaction of aminated lignin and the zirconium cluster-based MOF (UIO-66-NH2) as an adsorbent of methyl orange (MO). The results showed that UIO-g-NL maintained the original crystal structure and aminated lignin was successfully introduced after functionalization. UIO-g-NL selectively adsorbed MO from a mixed solution 50 mg/L MO and 50 mg/L methylene blue (MB), with an adsorption efficiency of nearly 100%. In a mixed solution 250 mg/L MB and 250 mg/L MO, UIO-g-NL adsorbed both dyes with 1120.70 mg/g for MB and 961.54 mg/g for MO. Hydrogen bonding, π-π and NH-π interactions, and electrostatic attraction contribute to the MO adsorption by UIO-g-NL. In the MO/MB mixture, MO adsorption by UIO-g-NL follows the pseudo-second-order kinetic and Freundlich isotherm models, which is an endothermic, spontaneous, and feasible adsorption process. Furthermore, the MO adsorption efficiency of UIO-g-NL remained high (>90%) after six re-use cycles.

17.
J Ovarian Res ; 16(1): 196, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37730669

RESUMO

Ovarian cancer (OV) is the most fatal gynecological malignant tumor worldwide, with high recurrence rates and great heterogeneity. Pyroptosis is a newly-acknowledged inflammatory form of cell death with an essential role in cancer progression, though studies focusing on prognostic patterns of pyroptosis in OV are still lacking. Our research filtered 106 potential pyroptosis-related genes (PRGs) among the 6406 differentially expressed genes (DEGs) between the 376 TCGA-OV samples and 180 normal controls. Through the LASSO-Cox analysis, the 6-gene prognostic signature, namely CITED2, EXOC6B, MIA2, NRAS, SETBP1, and TRPV46, was finally distinguished. Then, the K-M survival analysis and time-dependent ROC curves demonstrated the promising prognostic value of the 6-gene signature (p-value < 0.0001). Furthermore, based on the signature and corresponding clinical features, we constructed and validated a nomogram model for 1-year, 2-year, and 3-year OV survival, with reliable prognostic values in TCGA-OV (p-value < 0.001) and ICGC-OV cohort (p-value = 0.040). Pathway analysis enriched several critical pathways in cancer, refer to the pyroptosis-related signature, while the m6A analysis indicated greater m6A level in high-risk group. We assessed tumor immune microenvironment through the CIBERSORT algorithm, which demonstrated the upregulation of M1 Macrophages and activated DCs and high expression of key immune checkpoint molecules (CTLA4, PDCD1LG2, and HAVCR2) in high-risk group. Interestingly, the high-risk group exhibited poor sensitivity towards immunotherapy and better sensitivity towards chemotherapies, including Vinblastine, Docetaxel, and Sorafenib. Briefly, the pyroptosis-related signature was a promising tool to predict prognosis and evaluate immune responses, in order to assist decision-making for OV patients in the realm of precision medicine.


Assuntos
Neoplasias Ovarianas , Piroptose , Humanos , Feminino , Piroptose/genética , Neoplasias Ovarianas/genética , Prognóstico , Docetaxel , Nomogramas , Microambiente Tumoral/genética , Proteínas Repressoras , Transativadores
18.
Dalton Trans ; 52(37): 13161-13168, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37656128

RESUMO

Urea electrolysis can be used to treat wastewater containing urea and alleviate the energy crisis, so it is one of the best ways to solve environmental and energy problems. This paper reports the synthesis of M doped NiVS (M = Co, Ce and Cr) composites by a simple hydrothermal process for the first time. What is noteworthy is that the Ce-NiVS material as a catalytic electrode requires only 141 mV overpotential for the hydrogen evolution reaction (HER) and 1.291 V potential for the urea oxidation reaction (UOR) at a current density of 10 mA cm-2 in 1.0 M KOH and 0.5 M urea mixed alkaline solution. Using Ce-NiVS/NF as both the anode and cathode for urea electrolysis, a current density of 10 mA cm-2 is driven by a voltage of only 1.55 V, which is better than most previous catalysts. Experimental results demonstrate that the excellent catalytic activity of Ce-NiVS materials is due to the formation of a large number of active sites and the improvement of conductivity due to doping with Ce. Density functional theory calculation shows that the VS4 material has a small Gibbs free energy of hydrogen adsorption, which plays a major role in the hydrogen production process, and Ce-NiS has a higher density of states (DOS) near the Fermi level, indicating that Ce-NiS has better electronic conductivity. The synergistic catalysis of VS4 and Ce-NiS promoted the hydrogen production performance of the Ce-NiVS material. This work provides guidance for the optimization and design of low-cost electrocatalysts to replace expensive precious metal-based electrocatalysts for overall urea electrolysis.

19.
bioRxiv ; 2023 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-37745324

RESUMO

Simple and fast detection of small molecules is critical to health and environmental monitoring. Methods for chemical detection often use mass spectrometers or enzymes; the former relies on expensive equipment and the latter is limited to those that can act as enzyme substrates. Affinity reagents like antibodies can target a variety of small-molecule analytes, but the detection requires successful design of chemically conjugated targets or analogs for competitive binding assays. Here, we developed a generalizable method for highly sensitive and specific in-solution detection of small molecules, using cannabidiol (CBD) as an example. Our sensing platform uses gold nanoparticles (AuNPs) functionalized with a pair of chemically induced dimerization (CID) nanobody binders (nano-binders), where CID triggers AuNPs aggregation and sedimentation in the presence of CBD. Despite moderate binding affinities of the two nano-binders to CBD ( K D s of ∼6 and ∼56 µM), a scheme consisting of CBD-AuNP pre-analytical incubation, centrifugation, and electronic detection (ICED) was devised to demonstrate a high sensitivity (limit of detection of ∼100 picomolar) in urine and saliva, a relatively short assay time (∼2 hours), a large dynamic range (5 logs), and a sufficiently high specificity to differentiate CBD from its analog, tetrahydrocannabinol. The high sensing performance was achieved with the multivalency of AuNP sensing, the ICED scheme that increases analyte concentrations in a small assay volume, and a portable electronic detector. This sensing system is readily coupled to other binders for wide molecular diagnostic applications.

20.
Artigo em Inglês | MEDLINE | ID: mdl-37747611

RESUMO

Earthquake is one of the main factors causing structural disasters in current buildings. Under earthquake action, adjacent building structures are generally in different vibration stages, and collisions may occur in the structures, which may cause serious damage to the structure. In order to prevent certain earthquakes from damaging the designed buildings, this article mainly introduced the design and analysis of a numerical algorithm for seismic nonlinear structural dynamic response based on the HVSR algorithm. This article evenly divided the acceleration response time series into 15 time periods and then selected the position corresponding to the peak point of instantaneous amplitude within each period as the selected data point position. The same seismic load can be applied at the bottom of the established nonlinear model to extract the dynamic response data of the top layer of the structure, and then, the instantaneous amplitude and corresponding instantaneous phases and frequencies of the main components of the structural dynamic response can be extracted through the time-varying filter and Hilbert transform based on the discrete analytic mode decomposition. Under the influence of these four ground motions, the collision force within the range of 0-50 kN accounted for over 87% of the total number of collisions. In the comparison results of collision response to peak displacement, the four ground motions all led to structural collision, and the collision inhibited the positive peak displacement response of node 1512. Compared with noncollision, the peak displacement was reduced by 27.273, 33.675, 27.727, and 37.248%, respectively. The peak displacement of 1512 nodes was suppressed and reduced by 18.856%. The results indicate that the HVSR algorithm can obtain the instantaneous characteristic parameters of nonlinear structural dynamic response and achieve model correction.

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