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1.
Acta Trop ; 250: 107083, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38070722

RESUMO

BACKGROUND: Alveolar echinococcosis (AE) can cause severe liver injury and be fatal if left untreated. Currently, there are no effective therapeutic options for AE-induced liver injury. Therefore, by exploring the changes of gene proteins in mice with damaged liver, we attempted to identify the key molecules of liver damage, and provide data that will enable the development of drugs targeting hepatic AE. METHODS: BALB/c mice were inoculated with protoscoleces via the hepatic portal vein. Three months later, B-ultrasound examination and Hematoxylin-eosin (H&E) staining were used to confirm liver damage in mice. RNA sequencing and Liquid chromatography-mass spectrometry (LC-MS) were used to screen differentially expressed molecules associated with liver damage through bioinformatics, and Quantitative Real-Time PCR (qRT-PCR) was used to verify their expression. RESULTS: B-ultrasound examination showed liver lesions in the infected group, and H&E staining showed liver inflammation, fibrosis and liver necrosis. RNA sequencing and LC-MS results showed changes in the levels of more than 1000 genes and proteins, with upregulation of immune and inflammation pathways. By contrast, the downregulated genes and proteins were mostly involved in various metabolic reactions. Correlation analysis was conducted between the transcriptome data and proteome data. The results revealed 240 differentially expressed genes, of which 192 were upregulated, and 48 were downregulated. Many of these genes were involved in metabolic reactions, such as Catalase (Cat), fatty acid synthase (Fasn), and IL-16 genes, which may have relevance to liver injury. The results of qRT-PCR were consistent with those of bioinformatics analysis. CONCLUSIONS: The mechanisms of liver injury in mice infected with Echinococcus multilocularis are complex, involving abnormal metabolism, oxidative stress, inflammatory response, and many other factors. This study provides the data for preliminary exploration for the development of targeted therapies against AE.


Assuntos
Equinococose , Echinococcus multilocularis , Hepatopatias , Camundongos , Animais , Fígado , Echinococcus multilocularis/genética , Inflamação , Transcriptoma
2.
BMC Musculoskelet Disord ; 24(1): 873, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-37950233

RESUMO

OBJECTIVE: Purpose This study aims to explore the clinical efficacy of laminospinous process ligament complex reimplantation combined with mini-titanium plate fixation in the treatment of thoracolumbar intraspinal tumors. METHODS: A retrospective analysis was performed on 43 cases of intraspinal tumors treated with thoracolumbar intraspinal tumor resection from August 2018 to March 2021, and 27 cases underwent laminospinous process ligament complex reimplantation combined with micro titanium plate shaping. Fixation (laminar replantation group), and 16 patients underwent laminectomy combined with pedicle screw internal fixation (laminectomy group). The operation time, blood loss, drainage tube removal time, cerebrospinal fluid leakage, spinal instability, and the incidence of secondary spinal stenosis were compared between the two groups. The pain VAS score, ODI score, and modified Macnab at the last follow-up were compared between the two groups. And the laminar fusion rate of the laminoplasty group was measured. RESULTS: Both groups successfully completed the surgery and obtained complete follow-up. The incidence of cerebrospinal fluid leakage and secondary spinal canal stenosis in the laminectomy group was lower than that in the laminectomy group, and the difference was statistically significant (P < 0.05). There was no statistically significant difference in the incidence of spinal instability between the two groups (P > 0.05). The operation time and intraoperative blood loss in the laminectomy group were less than those in the laminectomy group, and the drainage tube removal time was earlier than that in the laminectomy group. The difference was statistically significant (P < 0.05). At the final follow-up, there was no statistically significant difference in the pain VAS score, ODI score, and modified Macnab between the two groups (P > 0.05), but they were all significantly improved compared with preoperative ones. Fusion evaluation was conducted on the laminoplasty group. Two years after surgery, the fusion rate was 97.56% (40/41). CONCLUSIONS: The application of laminospinous process ligament complex reimplantation combined with mini titanium plate fixation during thoracolumbar intraspinal tumor resection can effectively reconstruct the spinal canal and posterior column structure, reduce the incidence of cerebrospinal fluid leakage and secondary spinal stenosis. The laminar fusion rate is high.


Assuntos
Neoplasias da Coluna Vertebral , Estenose Espinal , Humanos , Estenose Espinal/diagnóstico por imagem , Estenose Espinal/cirurgia , Titânio , Estudos Retrospectivos , Canal Medular/cirurgia , Laminectomia/efeitos adversos , Resultado do Tratamento , Reimplante , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Neoplasias da Coluna Vertebral/cirurgia , Ligamentos/cirurgia , Vazamento de Líquido Cefalorraquidiano/cirurgia , Dor/cirurgia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia
3.
Clin Cosmet Investig Dermatol ; 16: 3165-3170, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37937316

RESUMO

Herpes zoster is typically a blister rash involving a single skin group, caused by the reactivation of primary varicella zoster virus infection. Disseminated herpes zoster refers to the presence of more than 20 small blisters outside the primary or adjacent skin, which is rare and usually occurs in individuals with weakened immune function. This case described a patient diagnosed with disseminated herpes zoster, with a decrease in CD4 count (379 cells/mm3) and certain skin lesions. He was subsequently screened positive for HIV. Also, we summarized other studies on the CD4 value of HIV patients with herpes zoster. Overall, for herpes zoster patients with decreased CD4 levels and certain skin manifestations, such as diffuse, ulcerative, or pustular lesions, clinicians should be aware of HIV infection.

4.
J Health Organ Manag ; ahead-of-print(ahead-of-print)2023 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-37723597

RESUMO

PURPOSE: In this study, the expectancy disconfirmation model (EDM) was applied to explain the formation of public health emergency preparedness cooperative behavior (EPCB) as well as considering the roles of official media exposure and positive emotions. DESIGN/METHODOLOGY/APPROACH: The analysis was based on a sample of 374 respondents collected during the coronavirus (COVID-19) pandemic. A t-test was used to examine the differences in variables by sex, age and educational background. Hypothesis testing was conducted using structural equation modeling. Amos 24.0 and R 4.0.3 were used to analyze the data. FINDINGS: The results indicated that (1) official media exposure has a positive impact on expectations for and perceived performance of public services, as well as positive emotions; (2) the EDM can be used to explain public satisfaction with government public health services; and (3) public satisfaction and positive emotions have positive effects on EPCB; (4) EDM and positive emotions mediate the relationship between official media exposure and EPCB. ORIGINALITY/VALUE: This study provides practical implications for increasing the EPCB from the perspective of risk communication.


Assuntos
COVID-19 , Defesa Civil , Humanos , COVID-19/epidemiologia , Comportamento Cooperativo , Saúde Pública , Comunicação
5.
Clin Cosmet Investig Dermatol ; 16: 2083-2088, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37575148

RESUMO

Dermatosis neglecta (DN) is a rare psychogenic dermatosis. To our knowledge, this is the first reported case of DN based on exanthematous drug eruption. We report a 68-year-old Chinese male patient who presented with thick, yellowish-brown crusting on his face and scalp and scaly skin for 6 days. Dermoscopy revealed diffusely distributed yellow-green serescrust-like plaques with different sizes and uneven thickness on a red background, and some demonstrated dot or globular hemorrhages. We considered DN and exanthematous drug eruptions based on the combination of the clinical medication and the history before the rash.

6.
Infect Immun ; 91(5): e0002923, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37039643

RESUMO

Cystic echinococcosis (CE) is a common zoonotic parasitic disease that seriously impacts public health. However, the full spectrum of immune cell changes in Echinococcus granulosus infection, especially the negative immune regulation of subpopulations of regulatory T (Treg) cells, are not yet well understood. In this study, we used single-cell RNA sequencing and immunome repertoire (IR) sequencing to analyze 53,298 cells from the spleens and peripheral blood mononuclear cells (PBMCs) of healthy and E. granulosus-infected mice. We used immunofluorescence combined with RNA fluorescence in situ hybridization and quantitative real-time PCR to verify the sequencing results. Our results showed tissue-specific immune system alterations in mice infected with E. granulosus. E. granulosus-infected mice induced a subpopulation of CD4+ cells with type I interferon production potential. Furthermore, there were six different Treg cell subpopulations in vivo at three stages of differentiation, and Treg subpopulations of different classes and different stages of differentiation showed tissue specificity. After infection, the Lag3hi Treg and Gpr83+Igfbp4+ naive Treg subpopulations were specifically induced in PBMCs and the spleen, respectively. Furthermore, T follicular helper 2 (Tfh2) cells with high expression of Cxxc5 and Spock2 were found in E. granulosus-infected mice. Our data uncovered changes in the full spectrum of immune cells in mice following the late stages of E. granulosus infection, including subpopulations of cells that have not been emphasized in previous studies. These results further enrich the study of the bidirectional immunomodulatory mechanism and offer a different perspective for subsequent studies of infection in E. granulosus.


Assuntos
Equinococose , Echinococcus granulosus , Animais , Camundongos , Echinococcus granulosus/genética , Linfócitos T Reguladores , Hibridização in Situ Fluorescente , Leucócitos Mononucleares , Zoonoses , Análise de Sequência de RNA , Receptores Acoplados a Proteínas G , Proteínas de Ligação a DNA , Fatores de Transcrição
7.
Angew Chem Int Ed Engl ; 62(23): e202304301, 2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37026510

RESUMO

Methane conversion to higher hydrocarbons requires harsh reaction conditions due to high energy barriers associated with C-H bond activation. Herein, we report a systematic investigation of photocatalytic oxidative coupling of methane (OCM) over transition-metal-loaded ZnO photocatalysts. A 1 wt % Au/ZnO delivered a remarkable C2 -C4 hydrocarbon production rate of 683 µmol g-1 h-1 (83 % C2 -C4 selectivity) under light irradiation with excellent photostability over two days. The metal type and its interaction with ZnO strongly influence the selectivity toward C-C coupling products. Photogenerated Zn+ -O- sites enable CH4 activation to methyl intermediates (*CH3 ) migrating onto adjacent metal nanoparticles. The nature of the *CH3 -metal interaction controls the OCM products. In the case of Au, strong d-σ orbital hybridization reduces metal-C-H bond angles and steric hindrance, thereby enabling efficient methyl coupling. Findings indicate the d-σ center may be a suitable descriptor for predicting product selectivity during OCM over metal/ZnO photocatalysts.

8.
Skin Pharmacol Physiol ; 36(3): 160-164, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36917958

RESUMO

Autism is a neurodevelopmental disorder. Individuals with autism can exhibit multiple neurological symptoms such as deficit in social communication, restricted interests, and repetitive behaviors. Recent study showed that murine model of autism displays an increased transepidermal water loss (TEWL) and dry skin. But whether epidermal functions are also altered in children with autism is unknown. In the present study, TEWL, stratum corneum hydration, and skin surface pH were compared between children with autism (N = 56) and normal controls (N = 48). Our results showed that children with autism exhibited lower stratum corneum hydration levels, higher TEWL, and elevated skin surface pH in comparison to normal controls (p < 0.0001 for all). These results demonstrate that children with autism exhibit epidermal dysfunction.


Assuntos
Transtorno Autístico , Humanos , Criança , Animais , Camundongos , Transtorno Autístico/metabolismo , Epiderme/metabolismo , Água/metabolismo , Perda Insensível de Água , Pele
9.
Front Immunol ; 14: 1243204, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38187382

RESUMO

Echinococcosis is a common human and animal parasitic disease that seriously endangers human health and animal husbandry. Although studies have been conducted on vaccines for echinococcosis, to date, there is no human vaccine available for use. One of the main reasons for this is the lack of in-depth research on basic immunization with vaccines. Our previous results confirmed that recombinant antigen P29 (rEg.P29) induced more than 90% immune protection in both mice and sheep, but data on its induction of sheep-associated cellular immune responses are lacking. In this study, we investigated the changes in CD4+ T cells, CD8+ T cells, and antigen-specific cytokines IFN-γ, IL-4, and IL-17A after rEg.P29 immunization using enzyme-linked immunospot assay (ELISPOT), enzyme-linked immunosorbent assay (ELISA), and flow cytometry to investigate the cellular immune response induced by rEg.P29 in sheep. It was found that rEg.P29 immunization did not affect the percentage of CD4+ and CD8+ T cells in peripheral blood mononuclear cells (PBMCs), and was able to stimulate the proliferation of CD4+ and CD8+ T cells after immunization in vitro. Importantly, the results of both ELISPOT and ELISA showed that rEg.P29 can induce the production of the specific cytokines IFN-γ and IL-17A, and flow cytometry verified that rEg.P29 can induce the expression of IFN-γ in CD4+ and CD8+ T cells and IL-17A in CD4+ T cells; however, no IL-4 expression was observed. These results indicate that rEg.P29 can induce Th1, Th17, and Tc1 cellular immune responses in sheep against echinococcosis infection, providing theoretical support for the translation of rEg.P29 vaccine applications.


Assuntos
Equinococose , Echinococcus granulosus , Vacinas , Humanos , Animais , Camundongos , Ovinos , Interleucina-17 , Linfócitos T CD8-Positivos , Leucócitos Mononucleares , Células Th17 , Mieloblastina , Equinococose/prevenção & controle , Citocinas , ELISPOT , Imunidade
10.
J Health Organ Manag ; ahead-of-print(ahead-of-print)2022 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-35799312

RESUMO

PURPOSE: Enhancing the initiative and enthusiasm of emergency preparedness behaviors among Medical and Health Organization (MHO) staff is an effective measure to prevent and reduce losses from emergencies. In this study, emergency preparedness behavioral intentions were divided into noncooperative behavioral intentions (EPNCBI) and cooperative behavioral intentions (EPCBI) to discuss the impact brought by quality of life (QoL). The mediating effects of psychological capital (PsyCap) and perceived organizational support (POS) were also considered. DESIGN/METHODOLOGY/APPROACH: A web-based questionnaire was used for MHO staff in China, and a structural equation analysis of the data collected from 243 participants was conducted to test the hypotheses. FINDINGS: The empirical results reveal that: (1) QoL had a positive effect on EPNCBI, PsyCap and POS; (2) PsyCap had a positive effect on EPNCBI and EPCBI; (3) POS had a positive effect on PsyCap and EPCBI; (4) PsyCap mediated the relationship between QoL and EPNCBI, and the relationship between POS and EPNCBI; (5) PsyCap and POS mediated the relationship between QoL and EPCBI. PRACTICAL IMPLICATIONS: Improving MHO staff's QoL is an effective way to enhance positive behavioral outcomes. Furthermore, these findings could provide managers with valuable insight focusing their limited resources on enhancing the emergency preparedness of MHO staff by reinforcing the level of PsyCap and POS. ORIGINALITY/VALUE: This study provides important updated considerations for the application of positive psychology in the field of emergency preparedness.


Assuntos
Defesa Civil , Qualidade de Vida , Estudos Transversais , Humanos , Corpo Clínico , Inquéritos e Questionários
11.
Acta Biochim Biophys Sin (Shanghai) ; 54(4): 482-493, 2022 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-35607954

RESUMO

Echinococcus granulosus causes echinococcosis, an important zoonotic disease worldwide and a major public health issue. Vaccination is an economical and practical approach for controlling E. granulosus. We have previously revealed that a recombinant protein P29 (rEg.P29) is a good vaccine candidate against E. granulosus. However, T cell immunogenic epitopes have not been identified. In the present study, we use rEg.P29-immunized mice as models to screen immunogenic epitopes for the construction of a novel multi-epitope vaccine. We search for immunodominant epitopes from an overlapping peptide library to screen the peptides of rEg.P29. Our results confirm that rEg.P29 immunization in mice elicits the activation of T cells and induces cellular immune responses. Further analyses show that a T cell epitope within amino acids 86­100 of rEg.P29 elicits significant antigen-specific IFN-γ production in CD4+ and CD8+ T cells and promotes specific T-cell activation and proliferation. Collectively, these results provide a reference for the construction of a novel vaccine against broad E. granulosus genotypes based on epitopes of rEg.P29.


Assuntos
Equinococose , Epitopos de Linfócito T , Animais , Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos , Epitopos de Linfócito T/genética , Camundongos , Proteínas Recombinantes/genética , Zoonoses
12.
Parasitol Res ; 121(7): 1993-2008, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35511364

RESUMO

Echinococcosis is a worldwide zoonosis. The mechanism of the establishment, growth, and persistence of parasites in the host has not been fully understood. Exosomes are found to be a way of information exchange between parasites and hosts. They exist in various body fluids widely. There are few studies on host-derived exosomes and their miRNA expression profiles at different infection time points. In this study, BALB/c mice were intraperitoneally infected with protricercariae. Exosomes were extracted from plasma (0, 3, 9, and 20 weeks post infection), and the expression profiles of exosome miRNA in the peripheral blood of mice were determined using RNA-sequencing. Compared to the 0 week groups, 24, 35, and 22 differentially expressed miRNAs were detected in infected mouse at the three infection stages, respectively. The results showed that there were significant differences in the miRNAs of exosomes at different infection time points. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to annotate the different miRNAs. The results showed that the biological pathways of parasites changed significantly at different stages of infection, with many significant and abundant pathways involved in cell differentiation, inflammation, and immune response, such as MAPK signaling pathway, Th17 cell differentiation, Wnt signaling pathway, FoxO signaling pathway, Notch signaling pathway, etc. These results suggest that miRNA may be an important regulator of interactions between Echinococcus granulosus and host. The data provided here provide valuable information to increase understanding of the regulatory function of microRNAs in the host microenvironment and the mechanism of host-parasite interaction. This may help us to find targets for Echinococcus granulosus to escape host immune attack and control Echinococcus granulosus infection in the future.


Assuntos
Equinococose , Echinococcus granulosus , MicroRNAs , Animais , Equinococose/parasitologia , Echinococcus granulosus/fisiologia , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Camundongos , Camundongos Endogâmicos BALB C , MicroRNAs/genética , MicroRNAs/metabolismo
13.
BMC Vet Res ; 18(1): 165, 2022 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-35513847

RESUMO

BACKGROUND: Sheep are an important livestock species worldwide and an essential large-animal model for animal husbandry and veterinary research. Understanding fundamental immune indicators, especially T-lymphocyte parameters, is necessary for research on sheep diseases and vaccines, to better understand the immune response to bacteria and viruses for reducing the use of antibiotics and improving the welfare of sheep. We randomly selected 36 sheep of similar ages to analyze cell-related immune indicators in peripheral blood mononuclear cells (PBMCs). The proportions of CD4+ and CD8+ T cells in PBMCs were detected by flow cytometry. We used Concanavalin A (Con A) and Phorbol-12-myristate-13-acetate (PMA)/Ionomycin to stimulate PBMCs, and measured the expression of IFN-γ, IL-4, and IL-17A using enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot assay (ELISpot). Simultaneously, PMA/Ionomycin/brefeldin A (BFA) was added to PBMCs, then the expression of IFN-γ, IL-4, and IL-17A was detected by flow cytometry after 4 h of culturing. In addition, we observed the proliferation of PBMCs stimulated with Con A for 3, 4, and 5 days. RESULTS: The proportions of CD4+ T lymphocytes (18.70 ± 4.21%) and CD8+ T lymphocytes (8.70 ± 3.65%) were generally consistent among individuals, with a CD4/CD8 ratio of 2.40 ± 0.79. PBMCs produced high levels of IFN-γ, IL-4, and IL-17A after stimulation with PMA/Ionomycin and Con A. Furthermore, PMA/Ionomycin stimulation of PBMC yielded significantly higher cytokine levels than Con A stimulation. Flow cytometry showed that the level of IFN-γ (51.49 ± 11.54%) in CD8+ T lymphocytes was significantly (p < 0.001) higher than that in CD4+ T lymphocytes (14.29 ± 3.26%); IL-4 (16.13 ± 6.81%) in CD4+ T lymphocytes was significantly (p < 0.001) higher than that in CD8+ T lymphocytes (1.84 ± 1.33%), There was no difference in IL-17A between CD4+ (2.83 ± 0.98%) and CD8+ T lymphocytes (1.34 ± 0.67%). The proliferation of total lymphocytes, CD4+ T lymphocytes, and CD8+ T lymphocytes continued to increase between days 3 and 5; however, there were no significant differences in proliferation between the cell types during the stimulation period. CONCLUSIONS: Evaluating primary sheep immune indicators, especially T lymphocytes, is significant for studying cellular immunity. This study provided valuable data and theoretical support for assessing the immune response of sheep to pathogens and improving sheep welfare.


Assuntos
Linfócitos T CD8-Positivos , Citocinas , Animais , Linfócitos T CD4-Positivos/metabolismo , Citocinas/metabolismo , Citometria de Fluxo/veterinária , Interleucina-17/metabolismo , Interleucina-4 , Ionomicina/farmacologia , Leucócitos Mononucleares , Ativação Linfocitária , Ovinos , Acetato de Tetradecanoilforbol/metabolismo , Acetato de Tetradecanoilforbol/farmacologia
14.
Front Cell Infect Microbiol ; 12: 805010, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35360110

RESUMO

The globally distributed cystic echinococcosis (CE) is caused by the larval stage of Echinococcus granulosus (E. granulosus), a cosmopolitan and zoonotic disease with potentially life-threatening complications in humans. The emerging roles for extracellular vesicles (EVs) in parasitic infection include transferring proteins and modifying host cell gene expression to modulate host immune responses. Few studies focused on the host-derived EVs and its protein profiles. We focused on the EVs from mouse infected with E. granulosus at different stages. ExoQuick kit was used for isolating EVs from mouse plasma and ExoEasy Maxi kit was used for isolating protoscolex culture supernatant (PCS) and hydatid cyst fluid (HCF). Firstly, EVs were characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and immunoblot. Secondly, the proteins of plasma EVs were identified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The resulting LC-MS/MS data were processed using Maxquant search engine (v 1.5.2.8). Tandem mass spectra were researched against the mice and E. granulosus proteins database in the NCBI. The differentially expressed proteins are performed by proteomic label-free quantitative analysis and bioinformatics. Thirdly, in vitro experiment, the results of co-culture of plasma EVs and spleen mononuclear cells showed that 7W-EVs can increase the relative abundance of regulatory T (Treg) cells and IL-10. We further verified that EVs can be internalized by CD4+ and CD8+ T cells, B cells, and myeloid-derived suppressor cells (MDSC). These results implied host-derived EVs are multidirectional immune modulators. The findings can contribute to a better understanding of the role of host-derived EVs which are the optimal vehicle to transfer important cargo into host immune system. In addition, we have found several important proteins associated with E. granulosus and identified in infected mouse plasma at different stages. Furthermore, our study further highlighted the proteomics and immunological function of EVs from mouse infected with E. granulosus protoscoleces at different infection stages. We have laid a solid foundation for the role of EVs in cystic echinococcosis in the future research and supplemented a unique dataset for this E. granulosus.


Assuntos
Echinococcus granulosus , Vesículas Extracelulares , Animais , Linfócitos T CD8-Positivos , Cromatografia Líquida , Echinococcus granulosus/metabolismo , Vesículas Extracelulares/metabolismo , Imunidade , Camundongos , Proteômica/métodos , Espectrometria de Massas em Tandem
15.
Sensors (Basel) ; 22(7)2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35408042

RESUMO

Memory nonlinear error greatly reduces the performance of analog-to-digital converters (ADCs), and this effect is more serious in a time-interleaved analog-to-digital converter (TIADC) system. In this study, the sinusoidal wave fitting method was adopted and a joint error estimation method was proposed to address the memory nonlinear mismatch problem of the current TIADC system. This method divides the nonlinear error estimation method into two steps: the nonlinear mismatch error is coarsely estimated offline using the least squares (LS) method, and then accurately estimated online using the recursive least squares (RLS) method. After the estimation, digital post-compensation method is adopted. The obtained error parameters are used to reconstruct the error and then the reconstructed error is reduced at the output. This study used a four-channel 16-bit TIADC system with an effective number of bits (ENOB) value of 10.06 bits after the introduction of a memory nonlinearity error, which was increased to 15.42 bits after calibration by the joint error estimation method. As a result, the spurious-free dynamic range (SFDR) increased by 36.22 dB. This error estimation method can improve the error estimation accuracy and reduce the hardware complexity of implementing the error estimation system using a field programmable gate array (FPGA).


Assuntos
Computadores , Calibragem , Desenho de Equipamento , Análise dos Mínimos Quadrados
16.
Nanotechnology ; 33(18)2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35042196

RESUMO

The increasing energy and environmental problems have made clean energy-driven catalysis a hot research topic. Methane is an earth-abundant raw material but difficult to be converted by thermochemical processes. It is of great significance to seek novel strategies to convert methane into high-value chemicals. Herein, we synthesize a series of transition metal catalysts based on layered double hydroxide precursors which were used for photothermal methane nonoxidative coupling reactions. The strong photothermal and chemisorption effects of the derived transition metal nanostructures allow the efficient activation of methane molecules. Among them, alumina-supported metallic Ni and NiCo-alloy catalysts show excellent methane nonoxidative coupling activities, achieved hydrogen production rates of 4816.53µmol g-1h-1and 5130.9µmol g-1h-1, accompanied by liquid fuels production rates of 59.2 mg g-1h-1and 63 mg g-1h-1, respectively. The findings, therefore, provide a new strategy for methane nonoxidative coupling driven by light energy at mild conditions.

18.
Adv Mater ; 34(3): e2106662, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34695250

RESUMO

Inspired by green plants, artificial photosynthesis has become one of the most attractive approaches toward carbon dioxide (CO2 ) valorization. Semiconductor quantum dots (QDs) or dot-in-rod (DIR) nano-heterostructures have gained substantial research interest in multielectron photoredox reactions. However, fast electron-hole recombination or sluggish hole transfer and utilization remains unsatisfactory for their potential applications. Here, the first application of a well-designed ZnSe/CdS dot-on-rods (DORs) nano-heterostructure for efficient and selective CO2 photoreduction with H2 O as an electron donor is presented. In-depth spectroscopic studies reveal that surface-anchored ZnSe QDs not only assist ultrafast (≈2 ps) electron and hole separation, but also promote interfacial hole transfer participating in oxidative half-reactions. Surface photovoltage (SPV) spectroscopy provides a direct image of spatially separated electrons in CdS and holes in ZnSe. Therefore, ZnSe/CdS DORs photocatalyze CO2 to CO with a rate of ≈11.3 µmol g-1 h-1 and ≥85% selectivity, much higher than that of ZnSe/CdS DIRs or pristine CdS nanorods under identical conditions. Obviously, favored energy-level alignment and unique morphology balance the utilization of electrons and holes in this nano-heterostructure, thus enhancing the performance of artificial photosynthetic solar-to-chemical conversion.

19.
Angew Chem Int Ed Engl ; 60(42): 22963-22969, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34374187

RESUMO

Photocatalysis as one of the future environment technologies has been investigated for decades. Despite great efforts in catalyst engineering, the widely used powder dispersion and photoelectrode systems are still restricted by sluggish interfacial mass transfer and chemical processes. Here we develop a scalable bilayer paper from commercialized TiO2 and carbon nanomaterials, self-supported at gas-liquid-solid interfaces for photothermal-assisted triphase photocatalysis. The photogeneration of reactive oxygen species can be facilitated through fast oxygen diffusion over triphase interfaces, while the interfacial photothermal effect promotes the following free radical reaction for advanced oxidation of phenol. Under full spectrum irradiation, the triphase system shows 13 times higher reaction rate than diphase controlled system, achieving 88.4 % mineralization of high concentration phenol within 90 min full spectrum irradiation. The bilayer paper also exhibits high stability over 40 times cycling experiments and sunlight driven feasibility, showing potentials for large scale photocatalytic applications by being further integrated into a triphase flow reactor.

20.
Artigo em Inglês | MEDLINE | ID: mdl-34443995

RESUMO

Medical and Health Organization (MHO) staff's emergency preparedness awareness and behaviors are essential variables that affect public health emergency response effectiveness. Based on the theory of psychological capital and the theory of planned behavior (TPB), this study discusses the mechanism of the psychological characteristics of MHO staff on their emergency preparedness behavioral intention (EPBI). To verify the research model, we conducted a web-based questionnaire survey among 243 MHO staff from China and analyzed the data using the structural equation modeling software, AMOS 24.0 (IBM, New York, United States). The empirical results reveal that psychological capital significantly affected cognitive processes theorized by TPB. This study suggests that the positive psychological capital of MHO staff should be developed and managed to improve their EPBI.


Assuntos
Defesa Civil , Humanos , Intenção , Corpo Clínico , Teoria Psicológica , Inquéritos e Questionários
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