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1.
Rev Cardiovasc Med ; 25(3): 96, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-39076962

RESUMO

Background: Atrial fibrillation (AF), which occurs four to six times more frequently in hypertrophic cardiomyopathy (HCM) patients than in the general population, is the most common persistent arrhythmia and has a substantial therapeutic consequence. In HCM patients, there are currently no discovered signs that could be utilized to identify AF. Methods: From 2018 to 2022, 493 individuals with a continuous diagnosis of HCM were examined at Beijing Anzhen Hospital. AF was proven using routine electrocardiography (ECG), 24-hour Holter ECGs, or bedside ECGs. Echocardiography and blood tests were performed for all patients. Analysis and comparison of the traits were performed in HCM patients with AF (n = 77) and without AF (n = 416). Results: Age (p < 0.001), prevalence of ventricular tachycardia (VT, p < 0.001), prevalence of pulmonary artery hypertension (p = 0.027), and albumin-to-globulin ratio (AGR, p = 0.046) were all significantly higher in patients with AF, compared to patients without AF. In multivariate logistic analysis, age (odds ratio [OR], 1.063; 95% confidence interval [CI], 1.032-1.095; p < 0.001), history of VT (OR, 2.702; 95% CI, 1.007-7.255; p = 0.048), AGR (OR, 3.477; 95% CI, 1.417-8.536; p = 0.007), left atrial diameter (OR, 1.132; 95% CI, 1.073-1.194; p < 0.001), left ventricular end-diastolic diameter (OR, 0.861; 95% CI, 0.762-0.974; p = 0.017), left ventricular end-systolic diameter (OR, 1.239; 95% CI, 1.083-1.417; p = 0.002), and peak A wave velocity (OR, 0.983; 95% CI, 0.972-0.994; p = 0.002) were independently associated with AF in HCM patients. In the receiver operating characteristic curve analysis, the area under the curve for the established model was 0.819 (95% CI, 0.755-0.883, p = 0.033), with a sensitivity and specificity of 0.763 and 0.816, respectively, for AF occurrence in HCM patients. Conclusions: In individuals with HCM, a history of VT and a higher AGR are independently linked to AF. Further investigation is necessary to determine whether increased AGR represents a risk factor for embolic stroke or cardiovascular death.

2.
Sensors (Basel) ; 24(16)2024 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-39204873

RESUMO

Pilot behavior is crucial for aviation safety. This study aims to investigate the EEG characteristics of pilots, refine training assessment methodologies, and bolster flight safety measures. The collected EEG signals underwent initial preprocessing. The EEG characteristic analysis was performed during left and right turns, involving the calculation of the energy ratio of beta waves and Shannon entropy. The psychological workload of pilots during different flight phases was quantified as well. Based on the EEG characteristics, the pilots' psychological workload was classified through the use of a support vector machine (SVM). The study results showed significant changes in the energy ratio of beta waves and Shannon entropy during left and right turns compared to the cruising phase. Additionally, the pilots' psychological workload was found to have increased during these turning phases. Using support vector machines to detect the pilots' psychological workload, the classification accuracy for the training set was 98.92%, while for the test set, it was 93.67%. This research holds significant importance in understanding pilots' psychological workload.


Assuntos
Eletroencefalografia , Pilotos , Máquina de Vetores de Suporte , Carga de Trabalho , Humanos , Eletroencefalografia/métodos , Pilotos/psicologia , Carga de Trabalho/psicologia , Masculino , Adulto , Aviação
3.
Crit Rev Food Sci Nutr ; : 1-13, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37526321

RESUMO

Heavy metals are harmful environmental pollutants that have attracted widespread attention, attributed to their health hazards to humans and animals. Due to the non-degradable property of heavy metals, organisms are inevitably exposed to heavy metals such as arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg). Several studies revealed that heavy metals can cause reproductive damage by the excessive production of reactive oxygen species (ROS), which exacerbates oxidative stress, inflammation, and endocrine disruption. Natural antioxidants, mainly polyphenols, carotenoids, and vitamins, have been shown to mitigate heavy metal-induced reproductive toxicity potentially. In this review, accumulated evidences on the influences of four non-essential heavy metals As, Cd, Pb, and Hg on both males and females reproductive system were established. The purpose of this review is to explore the potential mechanisms of the effects of heavy metals on reproductive function and point out the potential biomarkers of natural antioxidants interventions toward heavy metal-induced reproductive toxicity. Notably, increasing evidence proven that the regulations of hypothalamic-pituitary-gonadal axis, Nrf2, MAPK, or NF-κB pathways are the important mechanisms for the amelioration of heavy metal induced reproductive toxicity by natural antioxidants. It also provided a promising guidance for prevention and management of heavy metal-induced reproductive toxicity.

4.
Ann Noninvasive Electrocardiol ; 28(2): e13010, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36165099

RESUMO

Atrial flutter (AFL) is the second most common atrial tachyarrhythmia after atrial fibrillation. Catheter ablation (CA) for typical AFL is well-established and has a high success rate and adequate safety. However, sick sinus syndrome (SSS) occasionally occurs when long-term, persistent AFL is terminated by ablation. Sinus node function cannot be assessed during AFL, and the preoperative prediction of underlying SSS has not yet been investigated. When this situation occurs, pacemaker implantation is often necessary. Here, we report a case of SSS after persistent AFL CA.


Assuntos
Fibrilação Atrial , Flutter Atrial , Ablação por Cateter , Humanos , Flutter Atrial/etiologia , Flutter Atrial/cirurgia , Síndrome do Nó Sinusal/cirurgia , Eletrocardiografia , Fibrilação Atrial/cirurgia , Ablação por Cateter/efeitos adversos , Resultado do Tratamento
5.
Appl Opt ; 62(8): 2039-2047, 2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-37133091

RESUMO

Feature extraction is a key step in hyperspectral image change detection. However, many targets with great various sizes, such as narrow paths, wide rivers, and large tracts of cultivated land, can appear in a satellite remote sensing image at the same time, which will increase the difficulty of feature extraction. In addition, the phenomenon that the number of changed pixels is much less than unchanged pixels will lead to class imbalance and affect the accuracy of change detection. To address the above issues, based on the U-Net model, we propose an adaptive convolution kernel structure to replace the original convolution operations and design a weight loss function in the training stage. The adaptive convolution kernel contains two various kernel sizes and can automatically generate their corresponding weight feature map during training. Each output pixel obtains the corresponding convolution kernel combination according to the weight. This structure of automatically selecting the size of the convolution kernel can effectively adapt to different sizes of targets and extract multi-scale spatial features. The modified cross-entropy loss function solves the problem of class imbalance by increasing the weight of changed pixels. Study results on four datasets indicate that the proposed method performs better than most existing methods.

6.
Sensors (Basel) ; 23(5)2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36904933

RESUMO

Due to optical noise, electrical noise, and compression error, data hyperspectral remote sensing equipment is inevitably contaminated by various noises, which seriously affect the applications of hyperspectral data. Therefore, it is of great significance to enhance hyperspectral imaging data quality. To guarantee the spectral accuracy during data processing, band-wise algorithms are not suitable for hyperspectral data. This paper proposes a quality enhancement algorithm based on texture search and histogram redistribution combined with denoising and contrast enhancement. Firstly, a texture-based search algorithm is proposed to improve the accuracy of denoising by improving the sparsity of 4D block matching clustering. Then, histogram redistribution and Poisson fusion are used to enhance spatial contrast while preserving spectral information. Synthesized noising data from public hyperspectral datasets are used to quantitatively evaluate the proposed algorithm, and multiple criteria are used to analyze the experimental results. At the same time, classification tasks were used to verify the quality of the enhanced data. The results show that the proposed algorithm is satisfactory for hyperspectral data quality improvement.

7.
Rev Cardiovasc Med ; 23(10): 342, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39077132

RESUMO

Background: Several complications can contribute to the risk of shock during the chronic total occlusion (CTO) percutaneous coronary intervention (PCI) procedure. However, some patients that develop shock do not exhibit any apparent complications, and few studies to date have discussed the risk of unexplained perioperative shock in patients undergoing CTO PCI. Accordingly, this study was designed with the goal of defining perioperative risk factors linked to the odds of unexplained shock during CTO PCI. Methods: In total, this study analyzed data from 924 patients that underwent CTO PCI without any in-hospital complications from January 2016-August 2021. Cardiologists collected data pertaining to patient clinical characteristics, laboratory findings, angiographic findings, and procedural characteristics. Patients were separated into two groups based upon whether or not they experienced perioperative shock. The relationship between specific variables and perioperative shock incidence was assessed via a multivariable stepwise logistic regression approach. A risk-scoring nomogram was then designed for use as a tool to guide patient risk assessment efforts during PCI procedural planning. Results: Overall, 4.8% of these patients (44/924) experienced unexplained perioperative shock. Independent predictors associated with unexplained shock during CTO PCI included baseline systolic pressure (odds ratio (OR) 0.968, 95% confidence interval (CI): 0.945-0.991), baseline heart rate (OR 1.055, 95% CI: 1.020-1.091), baseline hemoglobin (OR 0.970, 95% CI: 0.947-0.994), procedure duration (OR 1.008, 95% CI: 1.002-1.015), J-CTO score (OR 1.521, 95% CI: 1.021-2.267), and use of a retrograde approach (OR 3.252, 95% CI: 1.426-7.415). The unbiased C-index estimate was 0.859, and this model exhibited excellent calibration. Conclusions: The risk of unexplained shock is an important consideration for clinicians performing the CTO PCI procedure. These analyses revealed unexplained shock risk to be independently related to lower baseline systolic pressure, higher baseline heart rate, lower baseline hemoglobin, more procedure time, higher J-CTO score, and more use of a retrograde approach.

8.
BMC Cardiovasc Disord ; 22(1): 549, 2022 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-36526970

RESUMO

BACKGROUND: In recent years, the difference in outcomes of radiofrequency catheter ablation (RFCA) in persistent atrial fibrillation patients has risen. In particular, biological sex seems involved in a different response to the AF ablation procedure. In our study, we analyzed the AF recurrences after RFCA assessing the other association between male/female patients with the outcomes. METHODS: We enrolled 106 patients (74.5% men) with persistent atrial fibrillation with scheduled follow-up. The baseline clinical characteristics and AF recurrence after RFCA were compared between men and women. Cox regression analyses were performed to determine the risk predictors of AF recurrence. RESULTS: The proportion of RFCA in women was lower than that in men. Men with persistent AF were younger than women (58.6 ± 10.4 years vs. 65.1 ± 8.7 years, respectively; p = 0.003). The left atrium (LA) diameter was higher in males (43.7 ± 4.6 mm vs. 41.3 ± 5.5 mm; p = 0.028), and the level of left heart ejection fraction (LVEF) was higher in females (59.4 ± 6.9% vs. 64.1 ± 5.5%; p = 0.001). Sex differences in AF recurrence after RFCA were significant during the median 24.4-month (interquartile range: 15.2-30.6 months) follow-up period, and the recurrence rate of AF in women was significantly higher than that in men (p = 0.005). Univariable Cox regression analysis showed that female sex was a risk factor for persistent AF recurrence after RFCA [HR: 2.099 (1.087-4.053)]. Univariate Cox regression analysis revealed that non-PV ablation not associated with AF recurrence [HR: 1.003 (0.516-1.947)]. CONCLUSION: In a monocentric cohort of persistent AF patients, the female biological sex was associated with a higher risk of AF recurrence after RFCA.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Feminino , Humanos , Masculino , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Caracteres Sexuais , Recidiva , Resultado do Tratamento , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos
9.
Environ Res ; 211: 113064, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35271833

RESUMO

Frequently-occurred secondary organic aerosols (SOAs) under low-NOx conditions contribute to the winter haze episodes and remain unclear in the abundant presence of NH3. Here, the effects of CaCl2 seed particles on the photooxidation of low-molecular-weight C3H6 with co-existing NO2 and NH3 were highlighted and investigated through a chamber-simulation study equipped with high-resolution proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS). The influences of NH3 are often overestimated to exclusively enhance SOA yields under a low-[NO2]0 condition. Instead, the seeds played a central role in the heterogeneous formation of SOAs in this reaction with two orders of magnitudes higher than that in the absence of seeds at relative humidity (RH) of 82%. Interestedly, the O3 production was unchanged whether the seeds existed or not, small changes in the production of O3 were observed whether the seeds existed or not, indicating that the gas-phase conversions of C3H6 and NOx into C1-C3 oxygenated volatile organic compounds (OVOCs) and nitrogen-containing compounds (NOCs) were not affected by seed particles. Given that the ensuing formation of these low-volatile compounds was condensed into nucleation on the seeds, the explosive growth of C3H6 SOAs was then stimulated in the addition of NH3. Besides NO2 photolysis, the producing O3 was related to the formation of secondary carbonyls such as formaldehyde and then was consumed in the ·OH generation of approximately 3.40 × 10-12 molecules cm-3. This study provides a new insight to better understand the new gas-to-particle formation mechanisms when the haze pollution outbreaks in the complex air mixture.


Assuntos
Poluentes Atmosféricos , Compostos Orgânicos Voláteis , Aerossóis , Poluentes Atmosféricos/análise , Dióxido de Nitrogênio , Fotólise
10.
Ecotoxicol Environ Saf ; 239: 113623, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35567931

RESUMO

Bisphenol A (BPA) is an environmental endocrine disruptor. Recent studies have shown an association between decreased spermatogenesis and gut microbiota alteration. However, the potential associations and mechanisms of BPA exposure on spermatogenesis, hormone production, and gut microbiota remain unknown. This study aims to investigate BPA-induced male reproductive toxicity and the potential link with gut microbiota dysbiosis. Male Sprague Dawley rats were exposed to BPA at different doses by oral gavage for thirty consecutive days. The extent of testicular damage was evaluated by basic parameters of body weight and hematoxylin-eosin (H&E) staining. Next, we determined the mRNA levels and protein levels of apoptosis, histone-related factors, and mammalian target of rapamycin (mTOR) pathway in testes. Finally, 16 S rDNA sequencing was used to analyze gut microbiota composition after BPA exposure. BPA exposure damaged testicular histology, significantly decreased sperm count, and increased sperm abnormalities. In addition, BPA exposure caused oxidative stress and cell apoptosis in testes. The levels of histone (H2A, H3) were significantly increased, while ubiquitin histone H2A (ub-H2A) and ubiquitin histone H2B (ub-H2B) were markedly reduced. Furthermore, BPA activated the PI3K and AKT expression, but the protein expressions of mTOR and 4EBP1 in testes were inhibited significantly. Additionally, the relative abundance of class Gammaproteobacteria, and order Betaproteobacteriales was significantly higher when treated with a high dose of BPA compared to the control group, which was negatively correlated with testosterone level. This study highlights the relationship between BPA-induced reproductive toxicity and gut microbiota disorder and provides new insights into the prevention and treatment of BPA-induced reproductive damage.


Assuntos
Compostos Benzidrílicos , Microbioma Gastrointestinal , Histonas , Animais , Compostos Benzidrílicos/toxicidade , Disbiose/induzido quimicamente , Disbiose/metabolismo , Histonas/metabolismo , Masculino , Fenóis , Ratos , Ratos Sprague-Dawley , Sêmen , Serina-Treonina Quinases TOR/metabolismo , Testículo , Ubiquitinas/metabolismo
11.
Sensors (Basel) ; 22(5)2022 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-35271013

RESUMO

Most of the studies on vehicle control and stability are based on cases of known-road lateral slope, while there are few studies on road lateral-slope estimation. In order to provide reliable information on slope parameters for subsequent studies, this paper provides a method of structured-road lateral-slope estimation based on machine vision. The relationship between the road lateral slope and the tangent slope of the lane line can be found out according to the image-perspective principle; then, the coordinates of the pre-scan point are obtained by the lane line, and the tangent slope of the lane line is used to obtain a more accurate estimation of the road lateral slope. In the implementation process, the lane-line feature information in front of the vehicle is obtained according to machine vision, the lane-line function is fitted according to an SCNN (Spatial CNN) algorithm, then the lateral slope is calculated by using the estimation formula mentioned above. Finally, the road model and vehicle model are established by Prescan software for off-line simulation. The simulation results verify the effectiveness and accuracy of the method.

12.
J Environ Manage ; 316: 115273, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35576707

RESUMO

Emerging evidence suggests that residential open space (ROS) is beneficial for multiple health outcomes for urban residents. However, the general public's understanding of and demand for the health benefits related to ROS have not been widely explored. This study aims to examine the impact of residents' socioeconomic status and perceptions of landscape health benefits on their willingness to pay (WTP) for ROS and to evaluate the perceived monetary value of different residential landscape elements. An online survey with 1348 respondents was conducted between August 2020 and October 2021 in China using a contingent valuation (CV) method. Respondents perceived the landscape benefits related to mental health to be higher than those related to physical and social health. The perception of landscape health benefits positively affected WTP and the WTP value of ROS. Residents' monthly income was a significant influencing factor for WTP and the latter's value. For individuals with positive WTP, the average annual WTP for ROS was CNY 68.98 (USD 10.81), while for all the respondents, the estimated mean annual WTP for ROS was CNY 91.75 (USD 14.38). Moreover, the estimated WTP for plants was the highest, whereas the WTP for activity spaces was estimated as the lowest. These findings may improve city planners' and community managers' understanding of the perceived value of residential landscapes among the public and help them make effective decisions to build healthy communities.


Assuntos
Renda , Percepção , China , Cidades , Humanos , Espécies Reativas de Oxigênio , Inquéritos e Questionários
13.
Nucleic Acids Res ; 47(W1): W610-W613, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31066442

RESUMO

Quality control (QC) for lab-designed primers is crucial for the success of a polymerase chain reaction (PCR). Here, we present MFEprimer-3.0, a functional primer quality control program for checking non-specific amplicons, dimers, hairpins and other parameters. The new features of the current version include: (i) more sensitive binding site search using the updated k-mer algorithm that allows mismatches within the k-mer, except for the first base at the 3' end. The binding sites of each primer with a stable 3' end are listed in the output; (ii) new algorithms for rapidly identifying self-dimers, cross-dimers and hairpins; (iii) the command-line version, which has an added option of JSON output to enhance the versatility of MFEprimer by acting as a QC step in the 'primer design → quality control → redesign' pipeline; (iv) a function for checking whether the binding sites contain single nucleotide polymorphisms (SNPs), which will affect the consistency of binding efficiency among different samples. In summary, MFEprimer-3.0 is updated with the well-tested PCR primer QC program and it can be integrated into various PCR primer design applications as a QC module. The MFEprimer-3.0 server is freely accessible without any login requirement at: https://mfeprimer3.igenetech.com/ and https://www.mfeprimer.com/. The source code for the command-line version is available upon request.


Assuntos
Primers do DNA/normas , Reação em Cadeia da Polimerase/normas , Software , Algoritmos , Pareamento Incorreto de Bases , Sítios de Ligação , Primers do DNA/química , Genoma Humano , Humanos , Reação em Cadeia da Polimerase Multiplex/normas , Controle de Qualidade , Análise de Sequência
14.
Bioinformatics ; 35(9): 1566-1572, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30295699

RESUMO

MOTIVATION: Small non-coding RNAs (ncRNAs), especially microRNAs (miRNAs) and piwi-interacting RNAs (piRNAs), play key roles in many biological processes. However, only a few tools can be used to develop the optimal primer or probe design for the expression profile of small ncRNAs. Here, we developed sRNAPrimerDB, the first automated primer designing and query web service for small ncRNAs. RESULTS: The primer online designing module of sRNAPrimerDB is composed of primer design algorithms and quality evaluation of the polymerase chain reaction (PCR) primer. Five types of primers, namely, generic or specific reverse transcription primers, specific PCR primers pairs, TaqMan probe, double-hairpin probe and hybridization probe for different small ncRNA detection methods, can be designed and searched using this service. The quality of PCR primers is further evaluated using melting temperature, primer dimer, hairpin structure and specificity. Moreover, the sequence and size of each amplicon are also provided for the subsequent experiment verification. At present, 531 306 and 2 941 669 primer pairs exist across 223 species for miRNAs and piRNAs, respectively, according to sRNAPrimerDB. Several primers designed by sRNAPrimerDB are further successfully validated by subsequent experiments. AVAILABILITY AND IMPLEMENTATION: sRNAPrimerDB is a valuable platform that can be used to detect small ncRNAs. This module can be publicly accessible at http://www.srnaprimerdb.com or http://123.57.239.141. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Pequeno RNA não Traduzido/genética , Algoritmos , Primers do DNA , Reação em Cadeia da Polimerase , Software
15.
J Med Virol ; 92(9): 1609-1614, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32275081

RESUMO

Since the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in humans in late 2019, it has rapidly spread worldwide. To identify the biological characteristics of SARS-CoV-2 in a normal laboratory environment (biosafety level 2 [BSL-2]), a lentiviral-based nucleocapsid was used to carry the spike protein of SARS-CoV-2 onto the surface of pseudoviral particles as a surrogate model to evaluate the infective characterization of SARS-CoV-2. This study indicated that SARS-CoV-2 has extensive tissue tropism for humans and may infect monkeys and tree shrews but not rodents. More importantly, the use of pseudoviral particles in this study allows rapid assessment of neutralizing antibodies in serum in a BSL-2 laboratory. This study will provide a quick and easy tool for evaluating neutralizing antibodies in the serum of recovering patients and assessing the potency of candidate vaccines.


Assuntos
COVID-19/virologia , Engenharia Genética , Recombinação Genética , SARS-CoV-2/genética , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , Linhagem Celular , Células Cultivadas , Genes Reporter , Humanos , Testes de Neutralização , Especificidade de Órgãos , SARS-CoV-2/fisiologia , Especificidade da Espécie , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Transdução Genética , Vacinas Virais , Vírion/genética
16.
Phys Rev Lett ; 124(4): 047003, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32058786

RESUMO

We investigate the spatial and doping evolutions of the superconducting properties of trilayer cuprate Bi_{2}Sr_{2}Ca_{2}Cu_{3}O_{10+δ} by using scanning tunneling microscopy and spectroscopy. Both the superconducting coherence peak and gap size exhibit periodic variations with structural supermodulation, but the effect is much more pronounced in the underdoped regime than at optimal doping. Moreover, a new type of tunneling spectrum characterized by two superconducting gaps emerges with increasing doping, and the two-gap features also correlate with the supermodulation. We propose that the interaction between the inequivalent outer and inner CuO_{2} planes is responsible for these novel features that are unique to trilayer cuprates.

17.
Environ Sci Technol ; 53(18): 10906-10916, 2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31441306

RESUMO

Crystal facet-dominated surfaces determine the formation of surface-active complexes, and engineering specific facets is desirable for improving the catalytic activity of routine transition-metal oxides that often deactivate at low temperatures. Herein, MnOx-CeO2 was synthetically administered to tailor the exposure of three major facets, and their distinct surface-active complexes concerning the formation and quantitative effects of oxygen vacancies, catalytically active zones, and active-site behaviors were unraveled. Compared with two other low-index facets {110} and {001}, MnOx-CeO2 with exposed {111} facet showed higher activity for formaldehyde oxidation and CO2 selectivity. However, the {110} facet did not increase activity despite generating additional oxygen vacancies. Oxygen vacancies were highly stable on the {111} facet, and its bulk lattice oxygen at high migration rates could replenish the consumption of surface lattice oxygen, which was associated with activity and stability. High catalytically active regions were exposed at the {111}-dominated surfaces, wherein the predominated Lewis acid-base properties facilitated oxygen mobility and activation. The mineralization pathways of formaldehyde were examined by a combination of in situ X-ray photoemission spectroscopy and diffuse reflectance infrared Fourier transform spectrometry. The MnOx-CeO2-111 catalysts were subsequently scaled up to work as filter substrates in a household air cleaner. In in-field pilot tests, 8 h of exposure to an average concentration of formaldehyde after start-up of the air cleaner attained the Excellent Class of Indoor Air Quality Objectives in Hong Kong.


Assuntos
Formaldeído , Óxidos , Catálise , Hong Kong , Oxirredução
18.
Environ Sci Technol ; 53(9): 5230-5240, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-30990308

RESUMO

Formation and decay of formaldehyde oxides (CH2OO) affect the complete oxidation of formaldehyde. However, the speciation and reactivity of CH2OO are poorly understood because of its extremely fast kinetics and indirect measurements. Herein, three isomers of CH2OO (i.e., main formic acid, small dioxirane, and minor CH2OO Criegee) were in situ determined and confirmed as primary intermediates of the room-temperature catalytic oxidation of formaldehyde with two reference catalysts, that is, TiO2/MnO x-CeO2 and Pt/MnO x-CeO2. CH2OO Criegee is quite reactive, whereas formic acid and dioxirane have longer lifetimes. The production, stabilization, and removal of the three intermediates are preferentially performed at high humidity, matching well with the decay rate of CH2OO at approximately 6.6 × 103 s-1 in humid feed gas faster than 4.0 × 103 s-1 in dry feed. By contrast, given that a thinner water/TiO2 interface was well-defined in TiO2/MnO x-CeO2, fewer reductions in the active sites and catalytic activity were found when humidity was decreased. Furthermore, lethal intermediates mostly captured at the TiO2/MnO x-CeO2 surface suppressed the toxic off-gas emissions. This study provides practical insights into the rational design and selectivity enhancement of a reliable catalytic process for indoor air purification under unfavorable ambient conditions.


Assuntos
Formaldeído , Óxidos , Catálise , Cinética , Oxirredução
19.
Angew Chem Int Ed Engl ; 57(50): 16416-16420, 2018 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-30328235

RESUMO

We present an iron-containing metal-organic framework, MIL-100(Fe), for ozone removal. MIL-100(Fe) exhibits long-lasting ozone conversion efficiency of 100 % for over 100 h under a relative humidity of 45 % and space velocity of 1.9×105  h-1 at room temperature, which is well beyond the performance of most porous or metal catalysts such as activated carbon and α-MnO2 . We also investigated the impact of humidity level and elucidated the plausible reaction mechanism, which is further confirmed by DFT calculations. Furthermore, MIL-100(Fe) can be processed into films and used as filtration layer in a mask to protect personnel against ozone contamination. This study demonstrates the promising potential of MOFs in ozone pollution control, and also offers new insights for the design of ozone decomposition catalysts.

20.
J Clin Lab Anal ; 31(3)2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27558572

RESUMO

BACKGROUND: Diabetes mellitus is a metabolic disease that is characterized by hyperglycemia. Blood glucose (BG) is helpful for the diagnosis and treatment of diabetes and an important part of the management of diabetes. Point-of-care testing (POCT) is generally used by patients themselves or medical personnel to monitor BG. The objective of this article was to evaluate the accuracy and consistency of POCT on venous blood samples and compare it with the central laboratory system to determine the reliability of POCT measurement results as diagnostic criteria. METHOD: A total of 162 venous whole blood samples were pooled in this study, which included different concentrations and were determined by three POCT systems randomly. The results were compared with the central laboratory system, which uses the Glucose GOD-PAP method (HITACHI 7600-120). The accuracy was evaluated by the International Organization for Standardization (ISO) 15197:2013. RESULT: Bland-Altman and Passing-Bablok regression analysis showed three POCT systems that were comparable with the reference method (0.65, 95% CI: -0.57 to 1.86, Y = -0.11 + 0.95X for ACCU-CHEK® Performa; 0.40, 95% CI: -1.3 to 2.1, Y = 0.036 + 0.96X for ACCU-CHEK® Active; 0.70, 95% CI: -0.44 to 1.83, Y = -0.073 + 0.95X for OneTouch ® UltraVue). According to ISO 15197:2013, all POCT systems showed 100% of the results within 0.83 mmol/l (15 mg/dl) at BG concentrations <5.55 mmol/l (100 mg/dl); 92%, 89.2%, and 95.7% of the measurement results within 15% at BG concentrations ≥5.55 mmol/l (100 mg/dl) for ACCU-CHEK® Performa, ACCU-CHEK® Active, and OneTouch® UltraVue, respectively. CONCLUSIONS: The POCT system cannot replace the central laboratory system as a provider of a standard result in clinical diagnosis. It can only be used as a screening test.


Assuntos
Glicemia/análise , Laboratórios/normas , Testes Imediatos/normas , Adolescente , Adulto , Idoso , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Adulto Jovem
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