Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Angew Chem Int Ed Engl ; : e202407163, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38864252

RESUMO

Electrosynthesis of hydrogen peroxide (H2O2) based on proton exchange membrane (PEM) reactor represents a promising approach to industrial-level H2O2 production, while it is hampered by the lack of high-efficiency electrocatalysts in acidic medium. Herein, we present a strategy for the specific oxygen functional group (OFG) regulation to promote the H2O2 selectivity up to 92% in acid on cobalt-porphyrin molecular assembled with reduced graphene oxide. In-situ X-ray adsorption spectroscopy, in-situ Raman spectroscopy and Kelvin probe force microscopy combined with theoretical calculation unravel that different OFGs exert distinctive regulation effects on the electronic structure of Co center through either remote (carboxyl and epoxy) or vicinal (hydroxyl) interaction manners, thus leading to the opposite influences on the promotion in 2e- ORR selectivity. As a consequence, the PEM electrolyzer integrated with the optimized catalyst can continuously and stably produce the high-concentration of ca. 7 wt% pure H2O2 aqueous solution at 400 mA cm-2 over 200 h with a cell voltage as low as ca. 2.1 V, suggesting the application potential in industrial-scale H2O2 electrosynthesis.

2.
PLoS One ; 19(5): e0303508, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38768133

RESUMO

PURPOSE: The resurgence of pertussis has occurred around the world. However, the epidemiological profiles of pertussis cannot be well understood by current diseases surveillance. This study was designed to understand the seroepidemiological characteristics of pertussis infection in the general population of Huzhou City, evaluate the prevalence infection of pertussis in the population, and offer insights to inform adjustments in pertussis prevention and control strategies. METHODS: From September to October 2023, a cross-sectional serosurvey was conducted in Huzhou City, involving 1015 permanent residents. Serum samples were collected from the study subjects, and pertussis toxin IgG antibodies (Anti-PT-IgG) were quantitatively measured using enzyme-linked immunosorbent assay (ELISA). The analysis included the geometric mean concentration (GMC) of Anti-PT-IgG, rates of GMC≥40IU/mL, ≥100IU/mL, and <5IU/mL. Stratified comparisons were made based on age, vaccination history, and human categories. RESULTS: Among the 1015 surveyed individuals, the geometric mean concentration (GMC) of Anti-PT-IgG was 10.52 (95% CI: 9.96-11.11) IU/mL, with a recent infection rate of 1.58%, a serum positivity rate of 11.43%, and a proportion with <5IU/mL of 40.49%. Among 357 children with clear vaccination history, susceptibility decreased with an increasing number of vaccine doses (Z = -6.793, P < 0.001). The concentration of Anti-PT-IgG exhibited a significant post-vaccination decline over time (Z = -5.143, P < 0.001). In women of childbearing age, the GMC of Anti-PT-IgG was 7.71 (95% CI: 6.90-8.62) IU/mL, with no significant difference in susceptibility among different age groups (χ2 = 0.545, P = 0.909). The annual pertussis infection rate in individuals aged ≥3 years was 9321 (95%CI: 3336-16039) per 100,000, with peak infection rates in the 20-29, 40-49, and 5-9 age groups at 34363 (95%CI: 6327-66918) per 100,000, 22307.72 (95%CI: 1380-47442) per 100,000, and 18020(95%CI: 1093-37266) per 100,000, respectively. CONCLUSIONS: In 2023, the actual pertussis infection rate in the population of Huzhou City was relatively high. Vaccine-induced antibodies exhibit a rapid decay, and the estimated serum infection rate increases rapidly from post-school age, peaking in the 20-29 age group. It is recommended to enhance pertussis monitoring in adolescents and adults and refine vaccine immunization strategies.


Assuntos
Anticorpos Antibacterianos , Imunoglobulina G , Coqueluche , Humanos , Coqueluche/epidemiologia , Coqueluche/sangue , Coqueluche/imunologia , Coqueluche/prevenção & controle , Feminino , Estudos Transversais , Adulto , Masculino , China/epidemiologia , Estudos Soroepidemiológicos , Criança , Pessoa de Meia-Idade , Adolescente , Pré-Escolar , Adulto Jovem , Lactente , Imunoglobulina G/sangue , Anticorpos Antibacterianos/sangue , Idoso , Toxina Pertussis/imunologia , Prevalência , Vacina contra Coqueluche/imunologia , Vacinação , Bordetella pertussis/imunologia
3.
PLoS One ; 19(2): e0299488, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38416761

RESUMO

PURPOSE: To assess the epidemiology of seasonal influenza in Huzhou City, Zhejiang Province, China, during 2018-2022 and provide insights for influenza prevention. METHODS: Following the National Influenza Surveillance Program, we conducted pathogen surveillance by randomly sampling throat swabs from cases with influenza-like illness (ILI) at two sentinel hospitals. RESULTS: From 2018 to 2022, a total of 3,813,471 cases were treated at two hospitals in Huzhou, China. Among them, there were 112,385 cases of Influenza-Like Illness (ILI), accounting for 2.95% of the total number of cases. A total of 11,686 ILI throat swab samples were tested for influenza viruses, with 1,602 cases testing positive for influenza virus nucleic acid, resulting in a positivity rate of 13.71%. Among the positive strains, there were 677 strains of A(H3N2) virus, 301 strains of A(H1N1) virus, 570 strains of B/Victoria virus, and 54 strains of B/Yamagata virus. The ILI percentage (ILI%) and influenza nucleic acid positivity rate showed winter-spring peaks in the years 2018, 2019, 2021, and 2022, with the peaks concentrated in January and February. Additionally, a small peak was observed in August 2022 during the summer season. No peak was observed during the winter-spring season of 2020. The highest proportion of ILI cases was observed in children aged 0-4 years, followed by school-age children aged 5-14 years. There was a positive correlation between ILI% and influenza virus nucleic acid positivity rate (r = 0.60, p < 0.05). CONCLUSIONS: The influenza outbreak in Huzhou from 2020 to 2022 was to some extent influenced by the COVID-19 pandemic and public health measures. After the conclusion of the COVID-19 pandemic, the influenza outbreak in Huzhou may become more severe. Therefore, it is crucial to promptly assess the influenza outbreak trends based on the ILI% and the positivity rate of influenza virus nucleic acid tests.


Assuntos
COVID-19 , Vírus da Influenza A Subtipo H1N1 , Influenza Humana , Ácidos Nucleicos , Criança , Humanos , Influenza Humana/prevenção & controle , Vírus da Influenza A Subtipo H3N2 , Pandemias , China/epidemiologia , Estações do Ano , Hospitais , COVID-19/epidemiologia , Vigilância de Evento Sentinela
4.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1016496

RESUMO

Objective @#To understand the epidemiological characteristics of notifiable respiratory infectious diseases in Huzhou City, Zhejiang Province from 2017 to 2022, so as to provide insights into formulation of respiratory infectious disease prevention and control strategies.@*Methods@#The data pertaining to notifiable respiratory infectious disease in Huzhou City from 2017 to 2022 were collected through the Infectious Disease Report Information System of Chinese Disease Prevention and Control Information System. Epidemiological characteristics of notifiable respiratory infectious disease was analyzed using a descriptive epidemiological method.@*Results@#@*Conclusions@#A total of 31 314 cases of notifiable respiratory infectious diseases were reported in Huzhou City from 2017 to 2022, with an average annual reported incidence of 169.12/105. The reported incidence of notifiable respiratory infectious diseases appeared a tendency towards a rise in Huzhou City from 2017 to 2022 (P<0.05). The top six reported diseases in terms of case numbers were influenza (20 048 cases), tuberculosis (6 920 cases), COVID-19 (1 893 cases), mumps (1 413 cases), pertussis (475 cases) and scarlet fever (442 cases), accounting for 99.61% of the total cases. The incidence of influenza, COVID-19 and pertussis showed a tendency towards a rise, the incidence of mumps and tuberculosis showed a tendency towards a decline (all P<0.05), and scarlet fever remained at a low-level incidence (P>0.05). Respiratory infectious diseases were mainly reported in winter (January, February and December), with 14 644 cases accounting for 46.77%. There were 15 068 cases reported in schools and kindergartens, accounting for 48.12%. The incidence showed a U-shaped variation with age, with the highest incidence in residents at ages of 10 years and below (987.68/105), and showing a tendency towards a rise in residents at ages of 60 years and above. @*@#The incidence of respiratory infectious diseases in Huzhou City from 2017 to 2022 increased significantly. Influenza, tuberculosis, COVID-19, mumps and pertussis are key notifiable respiratory infectious diseases. Residents at ages of 10 years and below and 60 years and above should be given a high priority for respiratory infectious disease control.

5.
Int J Ophthalmol ; 16(11): 1746-1755, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38028520

RESUMO

AIM: To determine the in vitro protective effect of recombinant prominin-1 (Prominin-1)+microRNA-29b (P1M29) on N-methyl-D-aspartate (NMDA)-induced excitotoxicity in retinal ganglion cells (RGCs). METHODS: RGC-5 cells were cultured, and NMDA-induced excitotoxicity at the range of 100-800 µmol/L was assessed using the MTT assay. NMDA (800 µmol/L) was selected as the appropriate concentration for preparing the cell model. To evaluate the protective effect of P1M29 on the cell model, Prominin-1 was added at the concentration of 1-6 ng/mL for 48h, and the cell survival was investigated with/without microRNA-29b. After obtaining the appropriate concentration and time of P1M29 at 48h, real-time polymerase chain reaction (PCR) was utilized to detect the relative mRNA expression of vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-ß2. Western blot detection was applied to measure the phosphorylation levels of protein kinase B (AKT) and extracellular regulated protein kinases (ERK) in RGC-5 cells after treatment with Prominin-1. Apoptosis study of the cell model was conducted by flow cytometry for estimating the anti-apoptotic effect of P1M29. Immunofluorescence analysis was used to analyze the expression levels of VEGF and TGF-ß2. RESULTS: MTT cytotoxicity assays demonstrated that P1M29 group had significantly higher cell survival rate than Prominin-1 group (P<0.05). Real-time PCR data indicated that the expression levels of VEGF were significantly increased in both Prominin-1 and P1M29 groups compared NMDA and microRNA-29b group (P<0.05), while TGF-ß2 were significantly decreased in both microRNA-29b and P1M29 groups compared NMDA and Prominin-1 group (P<0.05). Western blot results showed that both Prominin-1 and P1M29 groups significantly increased the phosphorylation levels of AKT and ERK compared to NMDA and microRNA-29b groups (P<0.05). Flow cytometry analysis revealed that P1M29 could prevent RGC-5 cell apoptosis in the early stage of apoptosis, while immunofluorescence results showed that P1M29 group had higher expression of VEGF and lower expression of TGF-ß2 with a stronger green fluorescence than NMDA group. CONCLUSION: Prominin-1 combined with microRNA-29b can provide a suitable therapeutic option for ameliorating NMDA-induced excitotoxicity in RGC-5 cells.

6.
Molecules ; 28(16)2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37630337

RESUMO

Indocyanine green (ICG) is an important kind of near infrared (NIR) photosensitive molecules for PTT/PDT therapy as well as imaging. When exposed to NIR light, ICG can produce reactive oxygen species (ROS), which can kill cancer cells and pathogenic bacteria. Moreover, the absorbed light can also be converted into heat by ICG molecules to eliminate cancer cells. In addition, it performs exceptionally well in optical imaging-guided tumor therapy and antimicrobial therapy due to its deeper tissue penetration and low photobleaching properties in the near-infrared region compared to other dyes. In order to solve the problems of water and optical stability and multi-function problem of ICG molecules, composite nanomaterials based on ICG have been designed and widely used, especially in the fields of tumors and sterilization. So far, ICG molecules and their composite materials have become one of the most famous infrared sensitive materials. However, there have been no corresponding review articles focused on ICG molecules. In this review, the molecular structure and properties of ICG, composite material design, and near-infrared light- triggered anti-tumor, and antibacterial, and clinical applications are reviewed in detail, which of great significance for related research.


Assuntos
Dermatite Fototóxica , Verde de Indocianina , Humanos , Verde de Indocianina/farmacologia , Corantes , Antibacterianos , Temperatura Alta
7.
Nanoscale Adv ; 5(15): 3934-3941, 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37496618

RESUMO

Ag cluster catalyst-based oxidation of CO to CO2 is an important way to remove CO at low temperatures. However, the instability of silver clusters seriously limits the catalytic application. Herein, sub-nanosized EMT zeolite nanoparticles served as Ag cluster carriers with high selectivity, low coordination, and unsaturated atom active sites. The silver clusters with sub-nanometer size can be controlled with different charge states and loading rates. A detection film with 500 nm was further prepared by assembling the Ag-EMT composites with a small amount of Nalco as an adhesive. For CO detection, a completely enclosed gas sensing device based on in situ infrared spectroscopy was employed without air interference. CO was accurately introduced into the detection chamber and catalysed into CO2 by silver loaded EMT zeolite films, and the whole process was accurately recorded by infrared spectroscopy. CO with a detection range of 2-50 ppm was realized, showing great application potential in gas monitoring.

8.
Journal of Preventive Medicine ; (12): 811-813, 2023.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-997168

RESUMO

Objective@#To analyze the epidemiological characteristics of pertussis in Huzhou City, Zhejiang Province from 2012 to 2022, so as to provide insights into formulation of pertussis control measures.@*Methods@#The data of reported pertussis cases in Huzhou City from 2012 to 2022 were collected through the Infectious Disease Report Information System of Chinese Disease Prevention and Control Information System. The temporal, spatial and population distributions of pertussis cases in Huzhou City from 2012 to 2022 were analyzed using a descriptive epidemiological method.@*Results@#A total of 499 pertussis patients were reported in Huzhou City from 2012 to 2022, with mean annual reported incidence of 1.508/105, and no death was reported. The reported incidence of pertussis remained at a low level in Huzhou City from 2012 to 2021, all below 1/105, and increased to 12.625/105 in 2022. The reported incidence of pertussis appeared an overall tendency towards a rise in Huzhou City from 2012 to 2021 (Z=-29.261, P<0.001). The incidence of pertussis peaked from June to July, and a relatively higher incidence rate of pertussis was reported in Deqing (6.359/105) and Anji counties (1.725/105), while higher incidence was found among children at ages of <1 year (30.566/105), 4 years (31.896/105) and 5 years (29.485/105). @*Conclusion@#The reported incidence of pertussis was at a low level in Huzhou City from 2012 to 2021, and increased sharply in 2022. The incidence of pertussis peaked from June to July, was concentrated in Deqing and Anji counties and higher among infants under one year of age and preschool children at ages of 4 to 5 years.

9.
Materials (Basel) ; 17(1)2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38203869

RESUMO

Poly-γ-glutamic acid (γ-PGA) is a natural polymer composed of glutamic acid monomer and it has garnered substantial attention in both the fields of material science and biomedicine. Its remarkable cell compatibility, degradability, and other advantageous characteristics have made it a vital component in the medical field. In this comprehensive review, we delve into the production methods, primary application forms, and medical applications of γ-PGA, drawing from numerous prior studies. Among the four production methods for PGA, microbial fermentation currently stands as the most widely employed. This method has seen various optimization strategies, which we summarize here. From drug delivery systems to tissue engineering and wound healing, γ-PGA's versatility and unique properties have facilitated its successful integration into diverse medical applications, underlining its potential to enhance healthcare outcomes. The objective of this review is to establish a foundational knowledge base for further research in this field.

10.
Sensors (Basel) ; 22(3)2022 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-35161821

RESUMO

A typical and environment-friendly fluorescent polyamine-amine (PAMAM) features good compatibility and unique surface modification, while it is restricted by a low fluorescence property performance and an unclear fluorescence mechanism. In this work, we prepared blue fluorescent PAMAM polymer dots (PDs) via a simple hydrothermal method based on dichloromethane (DCM) and 2.0G PAMAM. The quantum yield achieved was 32.1%, which was 25 times stronger than that of 2.0G PAMAM due to the lone-pair electron leap of the amine groups, the aggregation of carbonyl groups, as well as the crosslinking induced by DCM inside the PAMAM. In addition, the fluorescent 2.0G PAMAM-DCM PDs show a great Fe3+ sensing property with the detection limit of 56.6 nM, which is much lower than the safety limits (5.36 µM) in drinking water, indicating its great potential for Fe3+ detection in aqueous media.


Assuntos
Pontos Quânticos , Carbono , Corantes Fluorescentes , Cloreto de Metileno , Poliaminas , Polímeros , Espectrometria de Fluorescência
11.
IEEE Trans Cybern ; 51(8): 4000-4010, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32886621

RESUMO

The problem of secure adaptive-event-triggered filter design with input constraint and hybrid cyber attack is investigated in this article. First, a new model of hybrid cyber attack, which considers a deception attack, a replay attack, and a denial-of-service (DoS) attack, is established for filter design. Second, an adaptive event-triggered scheme is applied to the filter design to save the limited communication resource. In addition, a novel adaptive-event-triggered filtering error model is established with the consideration of hybrid cyber attack and input constraint. Moreover, based on the Lyapunov stability theory and linear matrix inequality technique, sufficient conditions are obtained to guarantee the augmented system stability, and the parameters of the designed filter are presented with explicit forms. Finally, the proposed method is validated by simulation examples.

12.
Appl Opt ; 57(4): 602-606, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29400725

RESUMO

We demonstrate room temperature optically controllable group delay using population oscillation in an Er3+-doped fiber under a dual-frequency pumping laser. Using the numerical calculations, we study the effect of the pump power ratio (M) on the time delay and the group velocity of slow light propagation. The maximum time delay of 0.70 ms under a dual-frequency pump laser with two directions is obtained. Compared with a single pump method, the time delay can be increased with dual-frequency laser pumping. Moreover, we demonstrate clearly the influence of M on the maximum fractional delay and the optimal modulation frequency with an input signal power of 4.0 mW.

13.
Nat Commun ; 7: 11927, 2016 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-27311597

RESUMO

Nanolasers hold promise for applications including integrated photonics, on-chip optical interconnects and optical sensing. Key to the realization of current cavity designs is the use of nanomaterials combining high gain with high radiative efficiency. Until now, efforts to enhance the performance of semiconductor nanomaterials have focused on reducing the rate of non-radiative recombination through improvements to material quality and complex passivation schemes. Here we employ controlled impurity doping to increase the rate of radiative recombination. This unique approach enables us to improve the radiative efficiency of unpassivated GaAs nanowires by a factor of several hundred times while also increasing differential gain and reducing the transparency carrier density. In this way, we demonstrate lasing from a nanomaterial that combines high radiative efficiency with a picosecond carrier lifetime ready for high speed applications.

14.
ACS Nano ; 9(2): 1336-40, 2015 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-25565000

RESUMO

Unlike nanowires, GaAs nanosheets exhibit no twin defects, stacking faults, or dislocations even when grown on lattice mismatched substrates. As such, they are excellent candidates for optoelectronic applications, including LEDs and solar cells. We report substantial enhancements in the photoluminescence efficiency and the lifetime of passivated GaAs nanosheets produced using the selected area growth (SAG) method with metal organic chemical vapor deposition (MOCVD). Measurements are performed on individual GaAs nanosheets with and without an AlGaAs passivation layer. Both steady-state photoluminescence and time-resolved photoluminescence spectroscopy are performed to study the optoelectronic performance of these nanostructures. Our results show that AlGaAs passivation of GaAs nanosheets leads to a 30- to 40-fold enhancement in the photoluminescence intensity. The photoluminescence lifetime increases from less than 30 to 300 ps with passivation, indicating an order of magnitude improvement in the minority carrier lifetime. We attribute these enhancements to the reduction of nonradiative recombination due to the compensation of surface states after passivation. The surface recombination velocity decreases from an initial value of 2.5 × 10(5) to 2.7 × 10(4) cm/s with passivation.

15.
Nano Lett ; 15(1): 378-85, 2015 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-25426796

RESUMO

The development of earth abundant materials for optoelectronics and photovoltaics promises improvements in sustainability and scalability. Recent studies have further demonstrated enhanced material efficiency through the superior light management of novel nanoscale geometries such as the nanowire. Here we show that an industry standard epitaxy technique can be used to fabricate high quality II-V nanowires (1D) and nanoplatelets (2D) of the earth abundant semiconductor Zn3As2. We go on to establish the optoelectronic potential of this material by demonstrating efficient photoemission and detection at 1.0 eV, an energy which is significant to the fields of both photovoltaics and optical telecommunications. Through dynamical spectroscopy this superior performance is found to arise from a low rate of surface recombination combined with a high rate of radiative recombination. These results introduce nanostructured Zn3As2 as a high quality optoelectronic material ready for device exploration.

16.
Nano Lett ; 14(12): 7153-60, 2014 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-25382815

RESUMO

Using transient Rayleigh scattering (TRS) measurements, we obtain photoexcited carrier thermalization dynamics for both zincblende (ZB) and wurtzite (WZ) InP single nanowires (NW) with picosecond resolution. A phenomenological fitting model based on direct band-to-band transition theory is developed to extract the electron-hole-plasma density and temperature as a function of time from TRS measurements of single nanowires, which have complex valence band structures. We find that the thermalization dynamics of hot carriers depends strongly on material (GaAs NW vs InP NW) and less strongly on crystal structure (ZB vs WZ). The thermalization dynamics of ZB and WZ InP NWs are similar. But a comparison of the thermalization dynamics in ZB and WZ InP NWs with ZB GaAs NWs reveals more than an order of magnitude slower relaxation for the InP NWs. We interpret these results as reflecting their distinctive phonon band structures that lead to different hot phonon effects. Knowledge of hot carrier thermalization dynamics is an essential component for effective incorporation of nanowire materials into electronic devices.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...