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1.
Clin Lab ; 70(8)2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39193964

RESUMEN

BACKGROUND: Hemoglobin (HGB) is a pigment protein found in human red blood cells. Laboratories usually measure hemoglobin using a colorimetric method. The factor that causes the increase of blood turbidity (hypertri-glyceridemia) can lead to the false increase of HGB, and also cause a significant increase of MCH and MCHC. METHODS: By means of a case of hypertriglyceridemia, plasma exchange and formula substitution methods were used to establish a reliable calibration method for hemoglobin (HGB) determination. RESULTS: After calibration, the corrected final values of HGB and its related indexes MCH and MCHC differ greatly from the instrument values. We reported the calibrated results to clinicians. CONCLUSIONS: When using a commonly used clinical hematology analyzer to detect hemoglobin, when encountering high TG samples, plasma exchange and formula substitution methods can be used. It can quickly help us correct the HGB, MCH, and MCHC values in blood lipid samples and provide clinicians with accurate reports.


Asunto(s)
Hemoglobinas , Hipertrigliceridemia , Humanos , Calibración , Hipertrigliceridemia/sangre , Hipertrigliceridemia/diagnóstico , Hemoglobinas/análisis , Reproducibilidad de los Resultados , Masculino , Colorimetría/métodos , Triglicéridos/sangre
2.
Sci Bull (Beijing) ; 2024 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-39181785

RESUMEN

Exposure to polycyclic aromatic hydrocarbons (PAHs) in the Chinese population was among the highest globally and associated with various adverse effects. This study examines the impact of China's two-phase clean air initiatives, namely the Air Pollution Prevention and Control Action Plan (APPCAP) in 2013-2017 and the Blue-Sky Defense War (BSDW) in 2018-2020, on PAH levels and human exposures in Beijing. To evaluate the effects of APPCAP, we measured 16 PAHs in 287 PM2.5 samples collected in Beijing and 9 PAH metabolites in 358 urine samples obtained from 54 individuals who traveled from Los Angeles to Beijing between 2014 and 2018. The concentration of PM2.5-bound benzo[a]pyrene equivalents (BaPeq) decreased by 88.5% in 2014-2018 due to reduced traffic, coal, and biomass emissions. PAH metabolite concentrations in travelers' urine decreased by 52.3% in Beijing, correlated with changes in PM2.5 and NO2 levels. In contrast, no significant changes were observed in Los Angeles. To evaluate BSDW's effects, we collected 123 additional PM2.5 samples for PAH measurements in 2019-2021. We observed sustained reductions in BaPeq concentrations attributable to reductions in coal and biomass emissions during the BSDW phase, but those from traffic sources remained unchanged. After accounting for meteorological factors, China's two-phase clean air initiatives jointly reduced Beijing's PM2.5-bound BaPeq concentrations by 96.6% from 2014 to 2021. These findings provide compelling evidence for the effectiveness of China's clean air actions in mitigating population exposure to PAHs in Beijing.

3.
Fundam Res ; 4(3): 463-470, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38933216

RESUMEN

Bioaerosols are a subset of important airborne particulates that present a substantial human health hazard due to their allergenicity and infectivity. Chemical reactions in atmospheric processes can significantly influence the health hazard presented by bioaerosols; however, few studies have summarized such alterations to bioaerosols and the mechanisms involved. In this paper, we systematically review the chemical modifications of bioaerosols and the impact on their health effects, mainly focusing on the exacerbation of allergic diseases such as asthma, rhinitis, and bronchitis. Oxidation, nitration, and oligomerization induced by hydroxyl radicals, ozone, and nitrogen dioxide are the major chemical modifications affecting bioaerosols, all of which can aggravate allergenicity mainly through immunoglobulin E pathways. Such processes can even interact with climate change including the greenhouse effect, suggesting the importance of bioaerosols in the future implementation of carbon neutralization strategies. In summary, the chemical modification of bioaerosols and the subsequent impact on health hazards indicate that the combined management of both chemical and biological components is required to mitigate the health hazards of particulate air pollution.

4.
Environ Sci Technol ; 58(24): 10458-10469, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38836430

RESUMEN

Hepatic steatosis is the first step in a series of events that drives hepatic disease and has been considerably associated with exposure to fine particulate matter (PM2.5). Although the chemical constituents of particles matter in the negative health effects, the specific components of PM2.5 that trigger hepatic steatosis remain unclear. New strategies prioritizing the identification of the key components with the highest potential to cause adverse effects among the numerous components of PM2.5 are needed. Herein, we established a high-resolution mass spectrometry (MS) data set comprising the hydrophobic organic components corresponding to 67 PM2.5 samples in total from Taiyuan and Guangzhou, two representative cities in North and South China, respectively. The lipid accumulation bioeffect profiles of the above samples were also obtained. Considerable hepatocyte lipid accumulation was observed in most PM2.5 extracts. Subsequently, 40 of 695 components were initially screened through machine learning-assisted data filtering based on an integrated bioassay with MS data. Next, nine compounds were further selected as candidates contributing to hepatocellular steatosis based on absorption, distribution, metabolism, and excretion evaluation and molecular dockingin silico. Finally, seven components were confirmed in vitro. This study provided a multilevel screening strategy for key active components in PM2.5 and provided insight into the hydrophobic PM2.5 components that induce hepatocellular steatosis.


Asunto(s)
Interacciones Hidrofóbicas e Hidrofílicas , Material Particulado , Hígado Graso/inducido químicamente , Humanos , China , Contaminantes Atmosféricos
5.
Plants (Basel) ; 13(10)2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38794384

RESUMEN

OBJECTIVES: To slow down the chemical fixation of phosphate fertilizer, reduce the risk of active phosphorus leaching, stimulate the inherent phosphorus resource activity of soil, and improve phosphorus supply capacity. METHODS: This study utilized a combination of field experiments and indoor chemical analysis. Six types of exogenous organic matter (fulvic acid, biochar, compound microbial fertilizer, high-energy microbial inoculum, pig manure-vermicompost, cow manure-vermicompost) were added based on conventional fertilization. The experiment was conducted under the wheat-maize rotation system in the Huang-Huai-Hai region. RESULTS: Compared with control (CK) without exogenous organic matter (EOM), all the other treatments with EOM had an enhancing effect on the available phosphorus of the cultivated soil. During the maize harvest, the combined application of biochar, pig manure-vermicompost and cow manure-vermicompost treatment significantly increased the content of available phosphorus in 0-20 cm soil by 45.87-56.59% compared with CK. The combined application of fulvic acid, biochar, pig manure-vermicompost and cow manure-vermicompost treatment significantly increased the content of Ca2-P in 0-20 cm soil by 34.04-65.14%. The content of Ca10-P in each treatment with EOM exhibited a lower level compared to CK. EOM could slow down the fixation of phosphorus to some degree. Correlation analysis revealed significant associations between Ca2-P, Ca8-P, Al-P, Fe-P, neutral phosphatase activity, acid phosphatase activity, and the available phosphorus content in the soil. The combined application of fulvic acid, biochar, and cow manure-vermicompost could enhance the activity of neutral and acid phosphatase in topsoil to a certain extent, thereby facilitating the conversion of phosphorus into highly available Ca2-P. EOM could enhance the soil phosphorus availability and decelerate the conversion of soil phosphorus into O-P and Ca10-P forms with low availability. Among all treatments, biochar exhibited the most pronounced efficiency in mitigating phosphorus leaching downward. CONCLUSIONS: All the EOMs had the potential to enhance the conversion of phosphorus into soluble phosphorus (Ca2-P), thereby mitigating the chemical fixation of soil phosphorus and ameliorating non-point source pollution caused by phosphorus. EOM enhanced the activity of neutral and acid phosphatase, which was beneficial to the conversion of organic phosphorus to inorganic phosphorus and increasing the content of available phosphorus. All EOMs had good effects on the retention of soil effective phosphorus, among which biochar had the best effect on retaining effective phosphorus in the tillage layer and blocking phosphorus leaching downward.

6.
Bio Protoc ; 14(5): e4950, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38464941

RESUMEN

Here, we describe immunofluorescent (IF) staining assay of 3D cell culture colonoids isolated from mice colon as described previously. Primary cultures developed from isolated colonic stem cells are called colonoids. Immunofluorescence can be used to analyze the distribution of proteins, glycans, and small molecules-both biological and non-biological ones. Four-day-old colonoid cell cultures grown on Lab-Tek 8-well plate are fixed by paraformaldehyde. Fixed colonoids are then subjected to antigen retrieval and blocking followed by incubation with primary antibody. A corresponding secondary antibody tagged with desired fluorescence is used to visualize primary antibody-marked protein. Counter staining to stain actin filaments and nucleus to assess cell structure and DNA in nucleus is performed by choosing the other two contrasting fluorescences. IF staining of colonoids can be utilized to visualize molecular markers of cell behavior. This technique can be used for translation research by isolating colonoids from colitis patients' colons, monitoring the biomarkers, and customizing their treatments. Key features • Analysis of molecular markers of cell behavior. • Protocol to visualize proteins in 3D cell culture. • This protocol requires colonoids isolated from mice colon grown on matrigel support. • Protocol requires at least eight days to complete.

7.
Small ; 20(29): e2310762, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38366074

RESUMEN

Responsive thermochromic fiber materials capable of miniaturization and integrating comfortably and compliantly onto the soft and dynamically deforming human body are promising materials for visualized personal health monitoring. However, their development is hindered by monotonous colors, low-contrast color changes, and poor reversibility. Herein, full-color "off-on" thermochromic fluorescent fibers are prepared based on self-crystallinity phase change and Förster resonance energy transfer for long-term and passive body-temperature monitoring, especially for various personalized customization purposes. The off-on switching luminescence characteristic is derived from the reversible conversion of the dispersion state and fluorescent emission by fluorophores and quencher molecules, which are embedded in the matrix of a phase-change material, during the crystallizing/melting processes. The achievement of full-color fluorescence is attributed to the large modulation range of fluorescence colors according to primary color additive theory. These thermochromic fluorescent fibers exhibit good mechanical properties, fluorescent emission contrast, and reversibility, showing their great potential in flexible smart display devices. Moreover, the response temperature of the thermochromic fibers is controllable by adjusting the phase-change material, enabling body-temperature-triggered luminescence; this property highlights their potential for human body-temperature monitoring and personalized customization. This work presents a new strategy for designing and exploring flexible sensors with higher comprehensive performances.


Asunto(s)
Dispositivos Electrónicos Vestibles , Humanos , Monitoreo Fisiológico/instrumentación , Monitoreo Fisiológico/métodos , Color , Temperatura
8.
Sci Total Environ ; 917: 170612, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38307269

RESUMEN

Nitrated aromatic compounds (NACs) are key components of air pollution; however, due to the presence of complex mixtures of primary and secondary species, especially in urban environments, their atmospheric formation is poorly understood. Here we conducted a field campaign during a winter haze episode in urban Beijing, China to monitor gaseous and particulate NACs at 2-h time resolution. Through a standard-independent non-targeted approach, a total of 238 NACs were screened, of which 127 species were assigned chemical formula and 25 structures were confirmed. Four main classes were identified: nitrated aromatic hydrocarbons, nitrophenols, oxygenated nitrated aromatic compounds, and nitrated heterocyclic aromatic compounds. Hierarchical clustering analysis revealed disparate temporal variances of diurnal or nocturnal elevation, among which different nitration formations were captured, i.e., daytime photochemical oxidation and nighttime heterogeneous reactions. Isomeric information, particularly the substitution position of the nitro group on biphenyl, further demonstrated a potential heterogeneous mechanism of electrophilic nitration by NO2+. Assisted by source apportionment, we found that nighttime heterogeneous reactions significantly contributed to NAC formation, e.g., 31.3 % and 60.8 %, respectively, to 2-nitrofluoranthene and 2-nitropyrene, which were previously considered as classical daytime gas-phase products. This study provides comprehensive information on urban NAC species and highlights the importance of unheeded heterogeneous reactions in the atmosphere.

9.
Cryobiology ; 114: 104835, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38070820

RESUMEN

Cryopreservation is a crucial step in the supply process of off-the-shelf chimeric antigen receptor engineered natural killer (CAR-NK) cell products. Concerns have been raised over the clinical application of dimethyl sulfoxide (Me2SO) due to the potential for adverse reactions following infusion and limited cell-specific cytotoxic effects if misapplied. In this study, we developed a Me2SO-free cryopreservation medium specifically tailored for CAR-NK cells to address this limitation. The cryopreservation medium was formulated using human serum albumin (HSA) and glycerol as the base components. Following initial screening of seven clinically-compatible solutions, four with cryoprotective properties were identified. These were combined and optimized into a single formulation: IF-M. The viability, phenotype, and function of CAR-NK cells were evaluated after short-term and long-term cryopreservation to assess the effectiveness of IF-M, with Me2SO serving as the control group. The viability and recovery of CAR-NK cells in the IF-M group were significantly higher than those in the Me2SO group within 90 days of cryopreservation. Moreover, after 1 year of cryopreservation the cytotoxic capacity of CAR-NK cells cryopreserved with IF-M was comparable to that of fresh CAR-NK cells and significantly superior to that of CAR-NK cells cryopreserved in Me2SO. The CD107a expression intensity of CAR-NK cells in IF-M group was significantly higher than that of Me2SO group. No statistical differences were observed in other indicators under different cryopreservation times. These results underscore the robustness of IF-M as a suitable replacement for traditional Me2SO-based cryopreservation medium for the long-term cryopreservation and clinical application of off-the-shelf CAR-NK cells.


Asunto(s)
Criopreservación , Receptores Quiméricos de Antígenos , Humanos , Criopreservación/métodos , Crioprotectores/farmacología , Crioprotectores/metabolismo , Receptores Quiméricos de Antígenos/genética , Dimetilsulfóxido/farmacología , Dimetilsulfóxido/metabolismo , Células Asesinas Naturales , Supervivencia Celular
10.
Environ Sci Technol ; 57(49): 20657-20668, 2023 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-38029335

RESUMEN

Aromatic hydrocarbons are important contributors to the formation of ozone and secondary organic aerosols in urban environments. The different parallel pathways in aromatic oxidation, however, remain inadequately understood. Here, we investigated the production yields and chemical distributions of gas-phase tracer products during the photooxidation of alkylbenzenes at atmospheric OH levels with NOx present using high-resolution mass spectrometers. The peroxide-bicyclic intermediate pathway emerged as the major pathway in aromatic oxidation, accounting for 52.1 ± 12.6%, 66.1 ± 16.6%, and 81.4 ± 24.3% of the total OH oxidation of toluene, m-xylene, and 1,3,5-trimethylbenzene, respectively. Notably, the yields of bicyclic nitrates produced from the reactions of bicyclic peroxy radicals (BPRs) with NO were considerably lower (3-5 times) than what the current mechanism predicted. Alongside traditional ring-opening products formed through the bicyclic pathway (dicarbonyls and furanones), we identified a significant proportion of carbonyl olefinic acids generated via the 1,5-aldehydic H-shift occurring in subsequent reactions of BPRs + NO, contributing 4-7% of the carbon flow in aromatic oxidation. Moreover, the observed NOx-dependencies of ring-opening and ring-retaining product yields provide insights into the competitive nature of reactions involving BPRs with NO, HO2, and RO2, which determine the refined product distributions and offer an explanation for the discrepancies between the experimental and model-based results.


Asunto(s)
Ozono , Peróxidos , Oxidación-Reducción , Nitratos , Espectrometría de Masas , Aerosoles
11.
Sci Total Environ ; 887: 164114, 2023 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-37182762

RESUMEN

Organosulfur compounds (OSCs) are important components of fine particulate matter (PM2.5); however, little information is available on OSCs in urban regions due to their chemical complexity, especially for novel species such as aromatic sulfonates. To supplement the detection technique and systematically identify OSCs, in this study we developed a nontargeted approach based on gas chromatography and high-resolution mass spectrometry (GC-HRMS) to screen OSCs in PM2.5 of urban Beijing and provide field evidence for their source and formation mechanism. 76 OSCs were found through mass difference of sulfur isotopes and characteristic sulfur-containing fragments. 6 species were confirmed as aromatic sulfonates by authentic standards. 32 OSCs showed higher levels in the heating season, presumably because of the intensive emission, especially from coal combustion. While certain species, with 2-sulfobenzoic acid as the representative, were 2.6-times higher in the non-heating season than in the heating season. Such species were significantly correlated with ozone and aerosol liquid water content (r = 0.2-0.8, p < 0.05), implying an oxidation-involved aqueous-phase formation in the atmosphere. In addition, with an average proportion of ∼95 % of the total sulfobenzoic acids, the predominance of the 2-substitution product over its isomers of 3- or 4-sulfobenzoic acid suggests a more plausible mechanism of radical-initiated reaction of phthalic acid followed by sulfonation, with atmospheric reactivity indicated by ozone and temperature as the determining factor. This study provided not only a nontargeted approach for OSCs in ambient PM2.5, but also field evidence on their secondary formation proposed in previous simulation studies.

12.
Environ Sci Technol ; 57(13): 5160-5168, 2023 04 04.
Artículo en Inglés | MEDLINE | ID: mdl-36940425

RESUMEN

Polar nitrated aromatic compounds (pNACs) are key ambient brown carbon chromophores; however, their formation mechanisms, especially in the aqueous phase, remain unclear. We developed an advanced technique for pNACs and measured 1764 compounds in atmospheric fine particulate matter sampled in urban Beijing, China. Molecular formulas were derived for 433 compounds, of which 17 were confirmed using reference standards. Potential novel species with up to four aromatic rings and a maximum of five functional groups were found. Higher concentrations were detected in the heating season, with a median of 82.6 ng m-3 for Σ17pNACs. Non-negative matrix factorization analysis indicated that primary emissions particularly coal combustion were dominant in the heating season. While in the non-heating season, aqueous-phase nitration could generate abundant pNACs with the carboxyl group, which was confirmed by their significant association with the aerosol liquid water content. Aqueous-phase formation of 3- and 5-nitrosalicylic acids instead of their isomer of 4-hydroxy-3-nitrobenzoic acid suggests the existence of an intermediate where the intramolecular hydrogen bond favors kinetics-controlled NO2• nitration. This study provides not only a promising technique for the pNAC measurement but also evidence for their atmospheric aqueous-phase formation, facilitating further evaluation of pNACs' climatic effects.


Asunto(s)
Contaminantes Atmosféricos , Hidrocarburos Policíclicos Aromáticos , Material Particulado/análisis , Contaminantes Atmosféricos/análisis , Nitrocompuestos , Monitoreo del Ambiente , China , Estaciones del Año
13.
Food Res Int ; 164: 112407, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36737988

RESUMEN

Spoiled odors are a problem in thermally sterilized fermented soymilk. This study aims to clarify production conditions and key odorants of spoiled odors. The sensory evaluation showed that thermal sterilization caused a decrease in the sensory intensity of yogurt and fruity odors while significantly increasing undesirable aromas including beany, acidic, cooked-beans and spoiled odors. The spoiled odors increased with increasing acidity and heating temperatures. The strongest spoiled odor was observed in fermented soymilk at titratable acidity of 5.4 g/kg, sterilized at 90 °C. Apart from common volatiles that were inherent in soymilk and generated from lactic fermentation, 2-methyltetrahydrothiophen-3-one was found for the first time in soybean foods and was found to cause the spoiled odor. 44 volatiles found in thermally sterilized fermented soymilk were jointly formed its flavor wheel. This study provides important theoretical support for solving the problem of spoiled odor restricting the popularization of plant-based fermented soymilk.


Asunto(s)
Odorantes , Leche de Soja , Odorantes/análisis , Glycine max , Temperatura , Yogur
14.
Environ Sci Technol ; 57(2): 909-919, 2023 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-36594719

RESUMEN

The knowledge of the chemical composition of brown carbon (BrC) is limited to the categories of components or parts of specific organic components. In this paper, the light-absorbing properties and molecular compositions of lipid-soluble organic components in fine particulate matter of Beijing from 2016 to 2018, characterized by an ultraviolet-visible spectrometer and gas chromatography coupled with time-of-flight mass spectrometry, respectively, were combined to untargetedly screen the key BrC molecules by a partial least squares regression model for the first time. A total of 421 molecules were obtained, where 61 molecules were identified qualitatively and 22 molecules quantitatively. To the best of our knowledge, 11 molecules were newly identified BrC species. These qualitative molecules included polycyclic aromatic hydrocarbons with higher ambient concentrations and mass absorbing efficiencies (MAEs), as well as oxygen- and nitrogen-containing aromatic components with relatively lower concentrations and MAEs. The absorption contribution at 365 nm of quantified BrC species to lipid-soluble BrC during heating seasons was 39.1 ± 17.0%, which was about 5 times as high as previous studies. These results help establish a complete BrC molecular database and provide data support for better evaluating the climate effect of atmospheric carbonaceous aerosols and formulating air pollution control strategies.


Asunto(s)
Contaminantes Atmosféricos , Carbono , Beijing , Cromatografía de Gases y Espectrometría de Masas , Monitoreo del Ambiente/métodos , Material Particulado/análisis , Espectrometría de Masas , Aerosoles/análisis , Lípidos , Contaminantes Atmosféricos/análisis
15.
Biodivers Data J ; 11: e98405, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38327338

RESUMEN

Background: The genus Cantonius Théry, 1929 is a small group with two subgenera and 12 species. However, the biology of this genus is still unknown. New information: In this paper, three species of the genus Cantonius Théry, 1929 were found on bamboo leaves, revealing for the first time that Cantonius species are also leaf-miners. Two new species were recorded from Jiangxi Province and are described here: Cantonius (Cantonius) anjiensis sp. n. (host plant: Pleioblastusamarus) and Cantonius (Procantonius) qiyunensis sp. n. (host plant: Bambusablumeana) followed by C. (P.) austrisinicus Kalashian, 2021 (host plant: Oligostachyumpaniculatum) recorded from Guangxi Province. Including habitats, photos of three species together with C. (P.) qiyunensis sp. n. pupa, host plants, and leaf mines of the three species are presented. Moreover, the bionomics and habits of the genus are discussed for the first time, and a hypothesis for the distribution of Cantonius is provided.

16.
Molecules ; 27(19)2022 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-36235302

RESUMEN

Improving the utilization rate of pesticides is key to achieve a reduction and synergism, and adding appropriate surfactant to pesticide preparation is an effective way to improve pesticide utilization. Fluorinated surfactants have excellent surface activity, thermal and chemical stability, but long-chain linear perfluoroalkyl derivatives are highly toxic, obvious persistence and high bioaccumulation in the environment. Therefore, new strategies for designing fluorinated surfactants which combine excellent surface activity and environmental safety would be useful. In this study, four non-ionic gemini surfactants with short fluorocarbon chains were synthesized. The surface activities of the resulting surfactants were assessed on the basis of equilibrium surface tension, dynamic surface tension, and contact angle. Compared with their monomeric counterparts, the gemini surfactants had markedly lower critical micelle concentrations and higher diffusivities, as well as better wetting abilities. We selected a single-chain surfactant and a gemini surfactant with good surface activities as synergists for the glyphosate water agent. Both surfactants clearly improved the efficacy of the herbicide, but the gemini surfactant had a significantly greater effect than the single-chain surfactant. An acute toxicity test indicated that the gemini surfactant showed slight toxicity to rats.


Asunto(s)
Fluorocarburos , Herbicidas , Animales , Micelas , Sinergistas de Plaguicidas , Ratas , Soluciones , Tensoactivos , Agua
17.
J Opt Soc Am A Opt Image Sci Vis ; 39(10): 1839-1848, 2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-36215556

RESUMEN

The effective deployment of an intelligent reflecting mirror array (IRMA) can enhance channel quality and improve the system performance in visible light communications (VLC) systems. This paper focuses on the performance analysis and parameter optimization of an IRMA-aided VLC system. Initially, the channel gains of both line-of-sight (LoS) link and non-LoS links are analyzed. Then, considering the blockage probability of a LoS link, a theoretical expression of the average bit error rate (ABER) is derived. To further improve the system performance, the optimization problems about the parameters of the IRMA are formulated, and schemes are proposed to solve these problems. Moreover, a kind of hardware implementation of the IRMA is provided. Numerical results verify the accuracy of the derived ABER expression and the effectiveness of the proposed schemes.

18.
Environ Sci Technol ; 56(12): 7668-7678, 2022 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-35537182

RESUMEN

It is known that there are semiconductor oxides involved in mineral dust, which have photocatalytic properties. However, soot particles contained in carbonaceous aerosol and their photoactivity under sunlight are rarely realized. In this study, reactive oxygen species (ROS) such as superoxide anions and hydroxyl radicals were generated upon visible-light irradiation of soot particles, and the production activity was consistent with the carbonaceous core content, indicating that the atmospheric soot particles can serve as a potential photocatalyst. The increase of oxygen-containing functional groups, environmentally persistent free radicals, oxygenated polycyclic aromatic hydrocarbons, and the oxidative potential (OP) of soot after irradiation confirmed the occurrence of visible-light-triggered photocatalytic oxidation of the soot itself. The mechanism analyses suggested that the carbonaceous core caused the production of ROS, which subsequently oxidize the extractable organic species on the soot surface. It is oxidized organic extracts that are responsible for the enhancements of the OP, cell mortality, and intracellular ROS generation. These new findings shed light on both the photocatalytic role of the soot and the importance of ROS during the photochemical self-oxidation of soot triggered by visible light and will promote a more comprehensive understanding of both the atmospheric chemical behavior and health effects of soot particles.


Asunto(s)
Estrés Oxidativo , Hollín , Luz , Oxidación-Reducción , Especies Reactivas de Oxígeno , Hollín/química
19.
ChemSusChem ; 15(2): e202102326, 2022 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-34817114

RESUMEN

The construction of C-O bonds through C-H bond functionalization remains fundamentally challenging. Here, a practical chlorine radical-mediated aerobic oxidation of alkylarenes to carbonyls was developed. This protocol employed commercially available HCl as a hydrogen atom transfer (HAT) reagent and air as a sustainable oxidant. In addition, this process exhibited excellent functional group tolerance and a broad substrate scope without the requirement for external metal and oxidants. The mechanistic hypothesis was supported by radical trapping, 18 O labeling, and control experiments.


Asunto(s)
Hidrógeno , Oxidantes , Catálisis , Indicadores y Reactivos , Oxidación-Reducción
20.
Cryobiology ; 104: 47-55, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34800528

RESUMEN

The development of an effective cryopreservation method to achieve off-the-shelf and bioactive tissue-engineered constructs (TECs) is important to meet the requirements for clinical applications. The trehalose, a non-permeable cryoprotectant (CPA), has difficulty in penetrating the plasma membranes of mammalian cells and has only been used in combination with other cell penetrating CPA (such as DMSO) to cryopreserve mammalian cells. However, the inherent cytotoxicity of DMSO results in increasing risks with respect to cryopreserved cells. Therefore, in this study, permeable trehalose glycopolymers were synthesised for cryopreservation of TECs. The trehalose glycopolymers exhibited good ice inhibiting activities and biocompatibilities. Furthermore, the viability and function of TECs after cryopreservation with 5.0 wt% S2 were similar to those of the non-cryopreserved TECs. We developed an effective preservation strategy for the off-the-shelf availability of TECs.


Asunto(s)
Criopreservación , Trehalosa , Animales , Supervivencia Celular , Criopreservación/métodos , Crioprotectores/metabolismo , Crioprotectores/farmacología , Dimetilsulfóxido , Mamíferos/metabolismo , Trehalosa/metabolismo , Trehalosa/farmacología
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