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1.
Comput Biol Med ; 175: 108495, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38697003

RESUMEN

Allergic rhinitis is a common allergic disease with a complex pathogenesis and many unresolved issues. Studies have shown that the incidence of allergic rhinitis is closely related to genetic factors, and research on the related genes could help further understand its pathogenesis and develop new treatment methods. In this study, 446 allergic rhinitis-related genes were obtained on the basis of the DisGeNET database. The protein-protein interaction network was searched using the random-walk-with-restart algorithm with these 446 genes as seed nodes to assess the linkages between other genes and allergic rhinitis. Then, this result was further examined by three screening tests, including permutation, interaction, and enrichment tests, which aimed to pick up genes that have strong and special associations with allergic rhinitis. 52 novel genes were finally obtained. The functional enrichment test confirmed their relationships to the biological processes and pathways related to allergic rhinitis. Furthermore, some genes were extensively analyzed to uncover their special or latent associations to allergic rhinitis, including IRAK2 and MAPK, which are involved in the pathogenesis of allergic rhinitis and the inhibition of allergic inflammation via the p38-MAPK pathway, respectively. The new found genes may help the following investigations for understanding the underlying molecular mechanisms of allergic rhinitis and developing effective treatments.


Asunto(s)
Mapas de Interacción de Proteínas , Rinitis Alérgica , Humanos , Rinitis Alérgica/genética , Mapas de Interacción de Proteínas/genética , Bases de Datos Genéticas , Algoritmos , Biología Computacional/métodos , Redes Reguladoras de Genes
2.
BMC Vet Res ; 20(1): 187, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38730463

RESUMEN

BACKGROUND: Porcine epidemic diarrhea virus (PEDV), a type of coronavirus, is one of the main pathogens that can infect pigs of all ages. It causes diarrhea and acute death of newborn piglets, resulting in massive economic losses to the worldwide swine industry. While vaccination remains the primary approach in combating PEDV, it often fails to address all the challenges posed by the infection, particularly in light of the emergence of evolving mutant strains. Therefore, there is a critical need to identify potent antiviral drugs that can effectively safeguard pigs against PEDV infection. RESULTS: In this study, the antiviral efficacy of SP2509, a specific antagonist of Lysine-specific demethylase 1(LSD1), was evaluated in vitro. The RT-qPCR, Western blot, TCID50, and IFA showed that at a concentration of 1µmol/L, SP2509 significantly inhibited PEDV infection. Additionally, viral life cycle assays showed that SP2509 operates by impeding PEDV internalization and replication rather than attachment and release. Regarding mechanism, in Huh-7 cells, knockdowns LSD1 can suppress PEDV replication. This indicated that the inhibition effect of SP2509 on PEDV largely depends on the activity of its target protein, LSD1. CONCLUSION: Our results in vitro show that SP2509 can inhibit PEDV infection during the internalization and replication stage and revealed a role of LSD1 as a restriction factor for PEDV. These imply that LSD1 might be a target for interfering with the viral infection, and SP2509 could be developed as an effective anti-PEDV agent.


Asunto(s)
Antivirales , Histona Demetilasas , Virus de la Diarrea Epidémica Porcina , Replicación Viral , Virus de la Diarrea Epidémica Porcina/efectos de los fármacos , Animales , Antivirales/farmacología , Replicación Viral/efectos de los fármacos , Histona Demetilasas/antagonistas & inhibidores , Porcinos , Chlorocebus aethiops , Enfermedades de los Porcinos/virología , Enfermedades de los Porcinos/tratamiento farmacológico , Infecciones por Coronavirus/veterinaria , Infecciones por Coronavirus/tratamiento farmacológico , Infecciones por Coronavirus/virología , Células Vero
3.
Adv Colloid Interface Sci ; 329: 103200, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38788306

RESUMEN

Age-related macular degeneration (AMD) is a leading cause of vision loss in the elderly. The current standard treatment for AMD involves frequent intravitreal administrations of therapeutic agents. While effective, this approach presents challenges, including patient discomfort, inconvenience, and the risk of adverse complications. Nanoparticle-based intravitreal drug delivery platforms offer a promising solution to overcome these limitations. These platforms are engineered to target the retina specifically and control drug release, which enhances drug retention, improves drug concentration and bioavailability at the retinal site, and reduces the frequency of injections. This review aims to uncover the design principles guiding the development of highly effective nanoparticle-based intravitreal drug delivery platforms for AMD treatment. By gaining a deeper understanding of the physiology of ocular barriers and the physicochemical properties of nanoparticles, we establish a basis for designing intravitreal nanoparticles to optimize drug delivery and drug retention in the retina. Furthermore, we review recent nanoparticle-based intravitreal therapeutic strategies to highlight their potential in improving AMD treatment efficiency. Lastly, we address the challenges and opportunities in this field, providing insights into the future of nanoparticle-based drug delivery to improve therapeutic outcomes for AMD patients.

4.
J Phys Condens Matter ; 36(34)2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38744297

RESUMEN

Transition metal silicides represented by MoSi2have excellent oxidation resistance and are widely used as high-temperature anti-oxidation coatings in hot end components of power equipment. However, the mechanism of temperature-dependent growth of MoSi2oxidation products has not been revealed. Therefore, this study investigated the formation characteristics of oxide film and silicide-poor compound on MoSi2at temperatures of 1000 °C-1550 °C through high-temperature oxidation experiments, combined with microscopic Raman spectroscopy, scanning electron microscope, and x-ray diffraction (XRD) characterizations. The result showed that MoSi2underwent high-temperature selective oxidation reactions at 1000 °C-1200 °C, forming MoO2and SiO2oxide film on the substrate. As the oxidation temperature increased to 1550 °C, after 100 h of oxidation, along with the disappearance of MoO2and the phase transformation of SiO2, a continuous Mo5Si3layer with a thickness of approximately 47µm was formed at the SiO2-MoSi2interface. Thermodynamics and kinetic calculations further revealed the mechanism of temperature-dependent growth of oxidation products (MoO2and Mo5Si3) during high-temperature oxidation process of MoSi2. As the temperature increased, the diffusion flux ratio of O and Si decreased, leading to a decrease in oxygen concentration at the interface and promoting the growth of the Mo5Si3layer. Its thickness is an important indicator for evaluating the oxidation resistance of MoSi2coatings during service. This study provides experimental and mechanistic insights into the temperature-dependent growth behavior of Mo5Si3during the high-temperature oxidation of MoSi2coating, and provides guidance for predicting the service life and improving the oxidation resistance of silicide coatings.

5.
Chem Biodivers ; : e202400568, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38771291

RESUMEN

 Four new monoterpene rhamnosides, graphiumisides A-D (1-4), along with four known steroid compounds (5-8) were isolated from the fermentation extract of animal-derived endophytic fungus, Graphium sp. GD-11. The chemical structures of all compounds were elucidated using 1D and 2D NMR, HRESIMS spectroscopic analyses, and other spectroscopic methods. Compounds 1-4 exhibit a distinctive structure connected by one p-menthane type monoterpene and one L-rhamnose. This is the first report of monoterpene glycosides from Graphium sp. All compounds (1-8) were tested for cytotoxic activities against four cancer cell lines (HepG2, SMMC7721, SW480, and A549), and only compound 1 showed weak anti-tumor activity against SMMC7721 cells.

6.
Chem Biodivers ; : e202400524, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38634793

RESUMEN

Baihe is a commonly used Chinese medicine for the treatment of neurological disorders. Clinically, the bulbs of Lilium brownii are used to act as Baihe. In the study, two new phenylpropanoid compounds including 3-O-acetyl-1-O-caffeoylglycerol (1) and 3-O-acetyl-1-O-p-coumaroylglycerol (2) were isolated from the bulbs of L. brownii. Their structures were identified by spectroscopic method and the effect on monoamine oxidase activity was determined using an enzyme labeling method. The results show 1 and 2 have anti-monoamine oxidase activity with 20.96 % and 22.31 % inhibition rates at 50 µg/ml, respectively.

7.
World Neurosurg ; 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38663738

RESUMEN

BACKGROUND: The operative classification of scoliosis is well-developed but inadequate for guiding conservative treatment. The current conservative classification for juvenile and adolescent idiopathic scoliosis (JAIS) exhibits noticeable deficiencies. This study aimed to establish the Peking Union Medical College Hospital (PUMCH) classification and assess its clinical value in the conservative treatment of JAIS. METHODS: This study consisted of 2 parts. First, it involved a retrospective analysis of patients treated for JAIS in the Department of Rehabilitation Medicine, the ∗∗∗ Union Medical College Hospital, between January 2013 and June 2020. Second, it involved an ambispective cohort study that enrolled patients with JAIS in the above hospital between July and December 2020. RESULTS: A total of 989 patients with JAIS were enrolled, with 899 patients for establishing the PUMCH classification and 90 patients with JAIS for validating the PUMCH classification. The classification demonstrated an average reliability of 88.22% with a kappa coefficient of 0.862. After 1 week, the remeasured results presented a mean reproducibility of 92.78% and a kappa coefficient of 0.908. After 1-year follow-up, the Cobb angle decreased significantly from 16.61 ± 2.88° to 12.16°± 9.97° (P = 0.002) in 51 patients with PUMCH-scoliosis-specific exercise (SSE) treatment, while the Cobb angle increased significantly from 15.74 ± 2.75° to 17.64 ± 5.60° (P = 0.014) in 39 patients without PUMCH-SSE treatment. CONCLUSIONS: The PUMCH-SSE classification demonstrates good inter-observer reliability and intra-observer reproducibility. In addition, the classification may be used to guide the conservative treatment of JAIS in clinical settings.

8.
Anal Chim Acta ; 1303: 342505, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38609273

RESUMEN

The development of sensitive and efficient cell sensing strategies to detect circulating tumor cells (CTCs) in peripheral blood is crucial for the early diagnosis and prognostic assessment of cancer clinical treatment. Herein, an array of hierarchical flower-like gold microstructures (HFGMs) with anisotropic nanotips was synthesized by a simple electrodeposition method and used as a capture substrate to construct an ECL cytosensor based on the specific recognition of target cells by aptamers. The complex topography of the HFGMs array not only catalyzed the enhancement of ECL signals, but also induced the cells to generate more filopodia, improving the capture efficiency and shortening the capture time. The effect of topographic roughness on cell growth and adhesion propensity was also investigated, while the cell capture efficiency was proposed to be an important indicator affecting the accuracy of the ECL cytosensor. In addition, the capture of cells on the electrode surface increased the steric hindrance, which caused ECL signal changes in the Ru(bpy)32+ and TPrA system, realizing the quantitative detection of MCF-7 cells. The detection range of the sensor was from 102 to 106 cells mL-1 and the detection limit was 18 cells mL-1. The proposed detection method avoids the process of separation, labeling and counting, which has great potential for sensitive detection in clinical applications.


Asunto(s)
Células Neoplásicas Circulantes , Humanos , Anisotropía , Ciclo Celular , Proliferación Celular , Oro
9.
World J Gastrointest Endosc ; 16(3): 108-111, 2024 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-38577650

RESUMEN

In this editorial, we comment on the minireview by Martino A, published in the recent issue of World Journal of Gastrointestinal Endoscopy 2023; 15 (12): 681-689. We focused mainly on the possibility of replacing the hepatic venous pressure gradient (HVPG) and endoscopy with noninvasive methods for predicting esophageal variceal bleeding. The risk factors for bleeding were the size of the varices, the red sign and the Child-Pugh score. The intrinsic core factor that drove these changes was the HVPG. Therefore, the present studies investigating noninvasive methods, including computed tomography, magnetic resonance imaging, elastography, and laboratory tests, are working on correlating imaging or serum marker data with intravenous pressure and clinical outcomes, such as bleeding. A single parameter is usually not enough to construct an efficient model. Therefore, multiple factors were used in most of the studies to construct predictive models. Encouraging results have been obtained, in which bleeding prediction was partly reached. However, these methods are not satisfactory enough to replace invasive methods, due to the many drawbacks of different studies. There is still plenty of room for future improvement. Prediction of the precise timing of bleeding using various models, and extracting the texture of variceal walls using high-definition imaging modalities to predict the red sign are interesting directions to lay investment on.

10.
Molecules ; 29(7)2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38611820

RESUMEN

The level of fluoride ions (F-) in the human body is closely related to various pathological and physiological states, and the rapid detection of F- is important for studying physiological processes and the early diagnosis of diseases. In this study, the detailed sensing mechanism of a novel high-efficiency probe (PBT) based on 2-(2'-hydroxyphenyl)-benzothiazole derivatives towards F- has been fully investigated based on density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods. F- attacks the O-P bond of PBT to cleavage the dimethylphosphinothionyl group, and the potential products were evaluated by Gibbs free energy and spectroscopic analyses, which ultimately identified the product as HBT-Enol1 with an intramolecular hydrogen bond. Bond parameters, infrared vibrational spectroscopy and charge analysis indicate that the hydrogen bond is enhanced at the excited state (S1), favoring excited state intramolecular proton transfer (ESIPT). The mild energy barrier further evidences the occurrence of ESIPT. Combined with frontier molecular orbital (FMO) analysis, the fluorescence quenching of PBT was attributed to the photoinduced electron transfer (PET) mechanism and the fluorescence turn-on mechanism of the product was attributed to the ESIPT process of HBT-Enol1.

11.
Nat Prod Res ; : 1-7, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38629157

RESUMEN

Icariin is the most bioactive ingredient of Epimedium L. and a quality marker of Herba Epimedii. Conventional methods for production of Icariin are known to be inefficient, resulting in low yields and significant environmental pollution. This study aimed to develop a sustainable and effective biphasic enzymatic hydrolysis system for the efficient conversion of epimedin C to icariin. The biphasic system was created using butyl acetate and phosphate buffer (pH 4.5) at a ratio of 3:1 (V/V) along with α-L-rhamnosidase/epimedin C (2 U/1 mg) at 50 °C for 12 h. Consequently, 98.21% of epimedin C was hydrolysed to icariin, with 95.62% of the product being transferred to the organic phase. Even after four cycles of use, the conversion ratio remained high at 75.28%. Furthermore, this novel strategy was also used for the conversion of Epimedium brevicornu Maxim. extracts. The biphasic system represents a sustainable and effective method for icariin production, offering potential benefits for industrial applications.

12.
Dalton Trans ; 53(19): 8168-8176, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38680066

RESUMEN

Room-temperature sodium-sulfur (RT Na-S) batteries have the drawbacks of the poor shuttle effect of soluble sodium polysulfides (NaPSs) as well as slow sulfur redox kinetics, which result in poor cycling stability and low capacity, seriously affecting their extensive application. Herein, defect engineering is applied to construct rich oxygen vacancies at the interface of a TiO2 anatase/rutile homojunction (OV-TRA) to enhance sulfur affinity and redox reaction kinetics. Combining structural characterizations with electrochemical analysis reveals that OV-TRA well alleviates the shuttle effect of NaPSs and precipitates the deposition and diffusion kinetics of Na2S. Consequently, S/OV-TRA provides excellent electrochemical performance with a reversible capacity of 870 mA h g-1 at 0.1 C after 100 cycles and a long-term cycling capability of 759 mA h g-1 at 1 C after 1000 cycles. This work provides an effective interfacial defect engineering strategy to promote the application of metal oxides in RT Na-S batteries.

13.
World J Gastroenterol ; 30(9): 1257-1260, 2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38577178

RESUMEN

The increasing popularity of endoscopic submucosal dissection (ESD) as a treatment for early gastric cancer has highlighted the importance of quality assessment in achieving curative resections. This article emphasizes the significance of evaluating ESD quality, not only for curative cases but also for non-curative ones. Postoperative assessment relies on the endoscopic curability (eCura) classification, but management strategies for eCuraC-1 tumour with a positive horizontal margin are unclear. Current research primarily focuses on comparing additional surgical procedures in high-risk patients, while studies specifically targeting eCuraC-1 patients are limited. Exploring management strategies and follow-up outcomes for such cases could provide valuable insights. Furthermore, the application of molecular imaging using near-infrared fluorescent tracers holds promise for precise tumour diagnosis and navigation, potentially impacting the management of early-stage gastric cancer patients. Advancing research in these areas is essential for improving the overall efficacy of endoscopic techniques and refining treatment indications.


Asunto(s)
Resección Endoscópica de la Mucosa , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/diagnóstico por imagen , Neoplasias Gástricas/cirugía , Neoplasias Gástricas/patología , Resección Endoscópica de la Mucosa/efectos adversos , Resección Endoscópica de la Mucosa/métodos , Resultado del Tratamiento , Estudios Retrospectivos , Mucosa Gástrica/diagnóstico por imagen , Mucosa Gástrica/cirugía , Mucosa Gástrica/patología
14.
Anal Chem ; 96(17): 6674-6682, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38642044

RESUMEN

Photodynamic therapy (PDT) is a significant noninvasive therapeutic modality, but it is often limited in its application due to the restricted tissue penetration depth caused by the wavelength limitations of the light source. Two-photon (TP) fluorescence techniques are capable of having an excitation wavelength in the NIR region by absorbing two NIR photons simultaneously, which offers the potential to achieve higher spatial resolution for deep tissue imaging. Thus, the adoption of TP fluorescence techniques affords several discernible benefits for photodynamic therapy. Organic TP dyes possess a high fluorescence quantum yield. However, the biocompatibility of organic TP dyes is poor, and the method of coating organic TP dyes with silica can effectively overcome the limitations. Herein, based on the TP silica nanoparticles, a functionalized intelligent biogenic missile TP-SiNPs-G4(TMPyP4)-dsDNA(DOX)-Aptamer (TGTDDA) was developed for effective TP bioimaging and synergistic targeted photodynamic therapy and chemotherapy in tumors. First, the Sgc8 aptamer was used to target the PTK7 receptor on the surface of tumor cells. Under two-photon light irradiation, the intelligent biogenic missile can be activated for TP fluorescence imaging to identify tumor cells and the photosensitizer assembled on the nanoparticle surface can be activated for photodynamic therapy. Additionally, this intelligent biogenic missile enables the controlled release of doxorubicin (DOX). The innovative strategy substantially enhances the targeted therapeutic effectiveness of cancer cells. The intelligent biogenic missile provides an effective method for the early detection and treatment of tumors, which has a good application prospect in the real-time high-sensitivity diagnosis and treatment of tumors.


Asunto(s)
Imagen Óptica , Fotoquimioterapia , Fotones , Fármacos Fotosensibilizantes , Humanos , Animales , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/uso terapéutico , Ratones , Nanopartículas/química , Doxorrubicina/química , Doxorrubicina/farmacología , Doxorrubicina/uso terapéutico , Dióxido de Silicio/química , Aptámeros de Nucleótidos/química , Colorantes Fluorescentes/química , Neoplasias/tratamiento farmacológico , Neoplasias/diagnóstico por imagen , Antineoplásicos/química , Antineoplásicos/farmacología , Ratones Desnudos , Línea Celular Tumoral , Ratones Endogámicos BALB C
15.
Nat Commun ; 15(1): 1895, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38429269

RESUMEN

The formation of charge density waves is a long-standing open problem, particularly in dimensions higher than one. Various observations in the vanadium antimonides discovered recently further underpin this notion. Here, we study the Kagome metal CsV3Sb5 using polarized inelastic light scattering and density functional theory calculations. We observe a significant gap anisotropy with 2 Δ max / k B T CDW ≈ 20 , far beyond the prediction of mean-field theory. The analysis of the A1g and E2g phonons, including those emerging below TCDW, indicates strong phonon-phonon coupling, presumably mediated by a strong electron-phonon interaction. Similarly, the asymmetric Fano-type lineshape of the A1g amplitude mode suggests strong electron-phonon coupling below TCDW. The large electronic gap, the enhanced anharmonic phonon-phonon coupling, and the Fano shape of the amplitude mode combined are more supportive of a strong-coupling phonon-driven charge density wave transition than of a Fermi surface instability or an exotic mechanism in CsV3Sb5.

16.
Protein J ; 2024 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-38436837

RESUMEN

Protein-protein interactions (PPIs) involve the physical or functional contact between two or more proteins. Generally, proteins that can interact with each other always have special relationships. Some previous studies have reported that gene ontology (GO) terms are related to the determination of PPIs, suggesting the special patterns on the GO terms of proteins in PPIs. In this study, we explored the special GO term patterns on human PPIs, trying to uncover the underlying functional mechanism of PPIs. The experimental validated human PPIs were retrieved from STRING database, which were termed as positive samples. Additionally, we randomly paired proteins occurring in positive samples, yielding lots of negative samples. A simple calculation was conducted to count the number of positive samples for each GO term pair, where proteins in samples were annotated by GO terms in the pair individually. The similar number for negative samples was also counted and further adjusted due to the great gap between the numbers of positive and negative samples. The difference of the above two numbers and the relative ratio compared with the number on positive samples were calculated. This ratio provided a precise evaluation of the occurrence of GO term pairs for positive samples and negative samples, indicating the latent GO term patterns for PPIs. Our analysis unveiled several nuclear biological processes, including gene transcription, cell proliferation, and nutrient metabolism, as key biological functions. Interactions between major proliferative or metabolic GO terms consistently correspond with significantly reported PPIs in recent literature.

17.
Sensors (Basel) ; 24(5)2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38474999

RESUMEN

In this study, a cationic amphiphilic self-assembling peptide (SAP) Z23 was designed, and a simple bisphenol a (BPA) sensor, based on SAP Z23/multiwalled carbon nanotubes (Z23/MWCNTs) composite, was successfully fabricated on the surface of a glassy carbon electrode (GCE). The composite material was formed by π-π stacking interaction between the aromatic group on the hydrophobic side of Z23 and the side-wall of MWCNTs, with the charged hydrophilic group of Z23 exposed. During the electrocatalytic process of BPA, a synergistic effect was observed between Z23 and MWCNTs. The current response of the sensor based on composite material was 3.24 times that of the MWCNTs-modified electrode, which was much higher than that of the peptide-based electrode. Differential pulse voltammetry (DPV) was used to optimize the experimental conditions affecting the analytical performance of the modified electrode. Under optimal conditions, the linear range of the sensor was from 10 nM to 100 µM by amperometric measurement with sensitivity and limit of detection (LOD) at 6.569 µAµM-1cm-2 and 1.28 nM (S/N = 3), respectively. Consequently, the sensor has excellent electrochemical performance and is easy to fabricate, making it a good prospect in the field of electrochemical detection in the future.


Asunto(s)
Compuestos de Bencidrilo , Nanocompuestos , Nanotubos de Carbono , Fenoles , Técnicas Electroquímicas/métodos , Nanotubos de Carbono/química , Límite de Detección , Nanocompuestos/química , Electrodos
18.
Dalton Trans ; 53(14): 6399-6409, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38498319

RESUMEN

A series of Tb3+-doped Sr2YTaO6 double perovskite phosphors (SYT:Tb3+) were synthesized using a conventional solid-state reaction method. A strong green emission was observed in the SYT:Tb3+ phosphors, and the optimal doping concentration of Tb3+ was confirmed to be 5 mol%. The electric dipole-dipole interaction was ascribed to be the main mechanism for the luminescence concentration quenching. Analysis of the concentration-dependent fluorescence decay confirmed that the self-generated quenching model holds for the dynamic process of Tb3+ decays in SYT. Furthermore, the internal quantum efficiencies, non-radiative transition rates, and energy transfer rates of the 5D4 level for the SYT:Tb3+ samples were estimated, respectively. The luminescence thermal stability of the sample was also evaluated based on the Arrhenius model. The chromaticity shift of the SYT:5 mol% Tb3+ phosphor was examined to be 0.013 when the sample temperature was increased from 303 to 483 K, thus indicating excellent chromaticity shifting resistance under high temperature conditions. Moreover, the Judd-Ofelt parameters were calculated from the emission spectra of SYT:Tb3+ to be Ω2 = 0.29 × 10-20, Ω4 = 0.45 × 10-20, and Ω6 = 0.72 × 10-20 cm2, respectively. The fluorescence branching ratios and radiative transition rates for the 5D4 level were calculated based on the obtained Judd-Ofelt parameters. Finally, a white light-emitting diode (LED) prototype was assembled using a 310 nm LED chip combined with a prepared green SYT:Tb3+ phosphor and two other commercial blue and red phosphors. The obtained warm white light exhibits good chromaticity coordinates (0.32, 0.32) and a high color rendering index of 96.1. Based on the above results, it can be known that the prepared SYT:Tb3+ phosphors have a potential application as green emitting phosphors in white LEDs.

19.
Materials (Basel) ; 17(6)2024 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-38541419

RESUMEN

The initial melting quality of a high-speed laser cladding layer has an important impact on its post-treatment and practical application. In this study, based on the repair of hydraulic support columns of coal mining machines, the influence of high-speed laser cladding process parameters on the quality of Fe-Cr-Ni alloy coatings was investigated to realize the accurate prediction of coating quality. The Taguchi orthogonal method was used to design the L25(56) test. The prediction models of the relationship between the cladding process and the coating quality were established using the Random Forest (RF) and AdaBoost (Adaptive Boosting, AB) algorithms, respectively. Then, the prediction accuracy of the two models was compared, and the process parameter features were screened for importance evaluation. The results show that the AB prediction model is more accurate than the RF prediction model and more sensitive to abnormal data. The importance evaluation based on the AdaBoost model shows that the scanning speed has a great influence on the height and surface roughness of the coating. On the other hand, the overlap rate is the most important factor in controlling the dilution ratio and near-surface grain size of high-speed laser melting coatings. In addition, the micro-hardness of the coating and the thermal effect of the substrate can be effectively enhanced by adjusting the laser power and scanning speed. Finally, it was verified that the AB prediction model could accurately estimate the quality indexes of the coating with a prediction error less than 6%. The results show that it is feasible to predict the quality of high-speed laser cladding with the AB algorithm. It provides a basis for the adjustment of process parameters in the subsequent quality control process of cladding.

20.
JMIR Public Health Surveill ; 10: e47165, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38502181

RESUMEN

BACKGROUND: The worldwide human monkeypox (mpox) outbreak in 2022 mainly affected men who have sex with men (MSM). In China, young men who have sex with men (YMSM) were at a potential high risk of mpox infection due to their sexual activeness and the eased COVID-19 restrictions at the end of 2022. OBJECTIVE: This study aimed to investigate the behavioral intention of receiving mpox vaccination and undergoing mpox testing in 4 different scenarios and explore their associations with background and behavioral theory-related factors among Chinese YMSM. METHODS: An online cross-sectional survey was conducted among YMSM aged 18-29 years from 6 representative provinces of China in September 2022. Participants recruited (recruitment rate=2918/4342, 67.2%) were asked to self-administer an anonymous questionnaire designed based on prior knowledge about mpox and classic health behavior theories. Data on the participants' background, mpox knowledge and cognition, mpox vaccination and testing cognition, and the behavioral intention of receiving mpox vaccination and undergoing mpox testing were collected. Descriptive analysis and univariate and multivariate linear regressions were performed. Geodetector was used to measure the stratified heterogeneity of behavioral intention. RESULTS: A total of 2493 YMSM with a mean age of 24.6 (SD 2.9) years were included. The prevalence of having a behavioral intention of receiving mpox vaccination ranged from 66.2% to 88.4% by scenario, varying in epidemic status and cost. The prevalence of having an mpox testing intention was above 90% in all scenarios regardless of the presence of symptoms and the cost. The positive factors related to vaccination intention included mpox knowledge (ba=0.060, 95% CI 0.016-0.103), perceived susceptibility of mpox (ba=0.091, 95% CI 0.035-0.146), perceived severity of mpox (ba=0.230, 95% CI 0.164-0.296), emotional distress caused by mpox (ba=0.270, 95% CI 0.160-0.380), perceived benefits of mpox vaccination (ba=0.455, 95% CI 0.411-0.498), self-efficacy of mpox vaccination (ba=0.586, 95% CI 0.504-0.668), and having 1 male sex partner (ba=0.452, 95% CI 0.098-0.806), while the negative factor was perceived barriers to vaccination (ba=-0.056, 95% CI -0.090 to -0.022). The positive factors related to testing intention were perceived severity of mpox (ba=0.283, 95% CI 0.241-0.325), perceived benefits of mpox testing (ba=0.679, 95% CI 0.636-0.721), self-efficacy of mpox testing (ba=0.195, 95% CI 0.146-0.245), having 1 male sex partner (ba=0.290, 95% CI 0.070-0.510), and having in-person gatherings with MSM (ba=0.219, 95% CI 0.072-0.366), while the negative factor was emotional distress caused by mpox (ba=-0.069, 95% CI -0.137 to -0.001). CONCLUSIONS: Among Chinese YMSM, the intention of undergoing mpox testing is optimal, while the mpox vaccination intention has room for improvement. A future national response should raise YMSM's mpox knowledge, disseminate updated information about mpox and preventive measures, improve preventive service accessibility and privacy, and provide advice on positively coping with the associated emotional distress.


Asunto(s)
Técnicas de Laboratorio Clínico , Mpox , Minorías Sexuales y de Género , Vacuna contra Viruela , Masculino , Humanos , Adulto Joven , Adulto , Homosexualidad Masculina , Estudios Transversales , Intención , China/epidemiología
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