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1.
Anal Chem ; 96(22): 9167-9176, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38761141

RESUMO

The detection of virus RNA in wastewater has been established as a valuable method for monitoring Coronavirus disease 2019. Carbon nanomaterials hold potential application in separating virus RNA owing to their effective adsorption and extraction capabilities. However, carbon nanomaterials have limited separability under homogeneous aqueous conditions. Due to the stabilities in their nanostructure, it is a challenge to efficiently immobilize them onto magnetic beads for separation. Here, we develop a porous agarose layered magnetic graphene oxide (GO) nanocomposite that is prepared by agglutinating ferroferric oxide (Fe3O4) beads and GO with agarose into a cohesive whole. With an average porous size of approximately 500 nm, the porous structure enables the unhindered entry of virus RNA, facilitating its interaction with the surface of GO. Upon the application of a magnetic field, the nucleic acid can be separated from the solution within a few minutes, achieving adsorption efficiency and recovery rate exceeding 90% under optimized conditions. The adsorbed nucleic acid can then be preserved against complex sample matrix for 3 days, and quantitatively released for subsequent quantitative reverse transcription polymerase chain reaction (RT-qPCR) detection. The developed method was successfully utilized to analyze wastewater samples obtained from a wastewater treatment plant, detecting as few as 10 copies of RNA molecules per sample. The developed aMGO-RT-qPCR provides an efficient approach for monitoring viruses and will contribute to wastewater-based surveillance of community infections.


Assuntos
Grafite , Nanocompostos , RNA Viral , Sefarose , Águas Residuárias , Grafite/química , Águas Residuárias/virologia , Águas Residuárias/química , RNA Viral/análise , RNA Viral/isolamento & purificação , Sefarose/química , Nanocompostos/química , Porosidade , Adsorção
2.
Environ Sci Technol ; 58(8): 3849-3857, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38349952

RESUMO

Reactive oxygen species (ROS) production in O2-perturbed subsurface environments has been increasingly documented in recent years. However, the constraining conditions under which abiotic and/or biotic mechanisms predominate for ROS production remain ambiguous. Here, we demonstrate that the ROS production mechanism, biotic and abiotic, is determined by sediment redox properties and sediment compositions. Upon the oxygenation of 10 field sediments, the cumulative H2O2 concentrations reached up to 554 µmol/kg within 2 h. The autoclaving sterilization experiments showed that H2O2 could be produced by both biotic and abiotic processes depending on the redox conditions. However, only the abiotic process could produce significant levels of •OH, and the production yield was closely related to the sediment components, particularly sediment Fe(II) and organic matter. Fe(II) bound with organic matter led to high yields of H2O2 and •OH production. Sediment oxygenation contributed to the appearance of H2O2 in groundwater, with the abiotic mechanism producing higher instantaneous H2O2 concentrations than the biotic mechanism. These findings reveal that the redox conditions, compositions, and texture of sediments collectively control abiotic and biotic mechanisms for ROS production, which assists the identification of ROS production hotspots and the understanding of ROS distribution and utilization in the subsurface.


Assuntos
Compostos Ferrosos , Peróxido de Hidrogênio , Espécies Reativas de Oxigênio , Oxirredução
3.
Molecules ; 29(10)2024 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-38792137

RESUMO

Bioelectrochemical systems (BESs) are an innovative technology for the efficient degradation of antibiotics. Shewanella oneidensis (S. oneidensis) MR-1 plays a pivotal role in degrading sulfamethoxazole (SMX) in BESs. Our study investigated the effect of BES conditions on SMX degradation, focusing on microbial activity. The results revealed that BESs operating with a 0.05 M electrolyte concentration and 2 mA/cm2 current density outperformed electrolysis cells (ECs). Additionally, higher electrolyte concentrations and elevated current density reduced SMX degradation efficiency. The presence of nutrients had minimal effect on the growth of S. oneidensis MR-1 in BESs; it indicates that S. oneidensis MR-1 can degrade SMX without nutrients in a short period of time. We also highlighted the significance of mass transfer between the cathode and anode. Limiting mass transfer at a 10 cm electrode distance enhanced S. oneidensis MR-1 activity and BES performance. In summary, this study reveals the complex interaction of factors affecting the efficiency of BES degradation of antibiotics and provides support for environmental pollution control.


Assuntos
Fontes de Energia Bioelétrica , Shewanella , Sulfametoxazol , Sulfametoxazol/metabolismo , Shewanella/metabolismo , Eletrodos , Biodegradação Ambiental , Antibacterianos/farmacologia , Antibacterianos/química , Eletrólise , Técnicas Eletroquímicas
4.
Molecules ; 29(5)2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38474526

RESUMO

Organic afterglow is a fascinating phenomenon with exceptional applications. However, it encounters challenges such as low intensity and efficiency, and typically requires UV-light excitation and facile intersystem crossing (ISC) due to its spin-forbidden nature. Here, we develop a novel strategy that bypasses the conventional ISC pathway by promoting singlet-triplet transition through the synergistic effects of the intra/intermolecular heavy-atom effect in aromatic crystals, enabling the direct population of triplet excited states from the ground state. The resulting materials exhibit a bright organic afterglow with a remarkably enhanced quantum efficiency of up to 5.81%, and a significantly increased organic afterglow lifetime of up to 157 microseconds under visible light. Moreover, given the high-efficiency visible-light excitable organic afterglow emission, the potential application is demonstrated in lifetime-resolved, color-encoded, and excitation wavelength-dependent pattern encryption. This work demonstrates the importance of the direct population method in enhancing the organic afterglow performance and red-shifting the excitation wavelength, and provides crucial insights for advancing organic optoelectronic technologies that involve triplet states.

5.
Small ; 19(31): e2207204, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36840641

RESUMO

Small interfering RNA (siRNA)-based gene therapy represents a promising strategy for tumor treatment. Novel gene vectors that can achieve targeted delivery of siRNA to the tumor cells without causing any side effects are urgently needed. To this end, the large amino acid mimicking carbon dots with guanidinium functionalization (LAAM GUA-CDs) are designed and synthesized by choosing arginine and dopamine hydrochloride as precursors. LAAM GUA-CDs can load siRNA through the multiple hydrogen bonds between their guanidinium groups and phosphate groups in siRNA. Meanwhile, the amino acid groups at the edges of LAAM GUA-CDs endow them the capacity to target tumors. After loading siBcl-2 as a therapeutic agent, LAAM GUA-CDs/siBcl-2 has a high tumor inhibition rate of up to 68%, which is twice more than that of commercial Lipofectamine 2000. Furthermore, LAAM GUA-CDs do not cause side effect during antitumor treatment owing to their high tumor-targeting ability, thus providing a versatile strategy for tumor-targeted siRNA delivery and cancer therapy.


Assuntos
Acetato de Metadil , Neoplasias , Humanos , RNA Interferente Pequeno , Guanidina , Aminoácidos , Carbono/química , Neoplasias/terapia , Neoplasias/tratamento farmacológico , Terapia Genética
6.
Environ Sci Technol ; 57(39): 14717-14725, 2023 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-37682840

RESUMO

Dioxins, such as polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), are among the most toxic unintentionally produced persistent organic pollutants, and their emission is of great concern. Herein, we discovered abundant dioxin formation in soil and various organic carbon-containing matrices after digestion with aqua regia. Σ17PCDD/Fs concentrations were in the range of 66.6-142,834 pg/g dw (5.6-17,021 pg WHO2005-TEQ/g dw) in 19 soil samples after digestion with aqua regia for 6 h. Σ17PCDD/Fs concentration was significantly and positively correlated with soil organic carbon content (R2 = 0.89; p < 0.01). Compared with cellulose and lignin, humic acid served as an important organic matter component that was converted to PCDD/Fs during soil digestion. Strong oxidation and production of reactive chlorine by aqua regia may be the key factors in the formation of PCDD/Fs. The yearly emission of PCDD/Fs due to digestion with strong acids by the inspection and testing industry was estimated to be 83.8 g TEQ in China in 2021 based on the highest level, which was ∼0.9% of the total dioxin inventory in China. Great attention should be paid to unexpected dioxin formation during digestion processes considering the potential risk of release from laboratories and enterprises.


Assuntos
Benzofuranos , Dioxinas , Bifenilos Policlorados , Dibenzodioxinas Policloradas , Solo , Carbono , Dibenzofuranos , Benzofuranos/análise , China , Dibenzofuranos Policlorados , Digestão , Monitoramento Ambiental
7.
Clin Exp Pharmacol Physiol ; 50(12): 944-953, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37688444

RESUMO

Myocardial fibrosis (MF) is involved in hypertension, myocardial infarction and heart failure. It has been reported that circular RNA (circRNA) is a key regulatory factor of MF progression. In this study, we revealed that circ_0002295 and CXCR2 were elevated, and miR-1287 was reduced in MF patients. Knockdown of circ_0002295 effectively suppressed the proliferation, migration and MF progression. Circ_0002295 was the molecular sponge of miR-12878, and miR-1287 inhibitor reversed the biological functions of circ_0002295 on the myocardial fibrosis. CXCR2 was a target gene of miR-1287, and CXCR2 silencing relieved the impacts of miR-1287 inhibitor on cardiac myofibroblasts. Circ_0002295 promoted MF progression by regulating the miR-1287/CXCR2 axis, providing a possible circRNA-targeted therapy for MF.


Assuntos
Insuficiência Cardíaca , MicroRNAs , Infarto do Miocárdio , Humanos , Linhagem Celular Tumoral , Proliferação de Células/genética , Coração , MicroRNAs/genética , Receptores de Interleucina-8B/genética , RNA Circular/genética
8.
Health Commun ; : 1-10, 2023 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-37635287

RESUMO

The affordances of social media, have significantly transformed how patients seek and process health information online, including those with chronic diseases like irritable bowel disease (IBD). Few studies have explored how information processing may impact symptom management. Guided by social cognitive theory, this study investigates how Chinese and U.S. patients (N = 838) process health information in a cross-cultural setting and the impact on symptom management. It finds that efficient information processing improves treatment understanding and symptom management for IBD patients, regardless of their cultural backgrounds. It also reveals a U-shaped quadratic relationship between IBD severity and emotional and peer support, indicating varying support needs at different IBD stages. These findings provide valuable insights for healthcare professionals, patients, and caregivers in designing interventions for chronic diseases. The study underscores the importance of recognizing the dynamics of health information processing and the need for a more nuanced approach to patient support and care.

9.
J Environ Sci (China) ; 123: 417-429, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36522003

RESUMO

Based on one-year observation, the concentration, sources, and potential source areas of volatile organic compounds (VOCs) were comprehensively analyzed to investigate the pollution characteristics of ambient VOCs in Haikou, China. The results showed that the annual average concentration of total VOCs (TVOCs) was 11.4 ppbV, and the composition was dominated by alkanes (8.2 ppbV, 71.4%) and alkenes (1.3 ppbV, 20.5%). The diurnal variation in the concentration of dominant VOC species showed a distinct bimodal distribution with peaks in the morning and evening. The greatest contribution to ozone formation potential (OFP) was made by alkenes (51.6%), followed by alkanes (27.2%). The concentrations of VOCs and nitrogen dioxide (NO2) in spring and summer were low, and it was difficult to generate high ozone (O3) concentrations through photochemical reactions. The significant increase in O3 concentrations in autumn and winter was mainly related to the transmission of pollutants from the northeast. Traffic sources (40.1%), industrial sources (19.4%), combustion sources (18.6%), solvent usage sources (15.5%) and plant sources (6.4%) were identified as major sources of VOCs through the positive matrix factorization (PMF) model. The southeastern coastal areas of China were identified as major potential source areas of VOCs through the potential source contribution function (PSCF) and concentration-weighted trajectory (CWT) models. Overall, the concentration of ambient VOCs in Haikou was strongly influenced by traffic sources and long-distance transport, and the control of VOCs emitted from vehicles should be strengthened to reduce the active species of ambient VOCs in Haikou, thereby reducing the generation of O3.


Assuntos
Poluentes Atmosféricos , Ozônio , Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/análise , Emissões de Veículos/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Ozônio/química , Alcanos/análise , Alcenos , China
10.
Environ Toxicol ; 37(7): 1686-1696, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35304817

RESUMO

Particulate matter 2.5 (PM2.5 ), a component of atmospheric particulate matter, leads to changes in gene expression and cellular functions. Epidemiological evidence confirms that PM2.5 has a positive correlation with lung injury. However, the molecular mechanisms involved remain poorly understood, and preventive methods are needed. In the present study, with human bronchial epithelial (HBE) cells in culture, we showed that low concentrations of PM2.5 resulted in acceleration of the G1/S transition and cell proliferation. Consistent with these effects, expression of the pro-inflammatory factor interleukin-6 (IL-6) was elevated in HBE cells exposed to PM2.5 . Accordingly, signal transducer and activator of transcription 3 (STAT3) was activated, which down-regulated expression of cyclin D1. In addition, PM2.5 exposure led to higher levels of miR-21, and there was a reciprocal loop between miR-21 and STAT3. For HBE cells, tanshinone IIA (Tan IIA) reversed the PM2.5 -induced cell cycle alteration and cell proliferation, and reduced the expression of cytokines (IL-6, STAT3, and miR-21). These results show that, for HBE cells, Tan IIA attenuates the PM2.5 -induced G1/S alteration and cell proliferation, and indicate that it has potential clinical application for PM2.5 -induced respiratory injuries.


Assuntos
Abietanos , MicroRNAs , Material Particulado , Fator de Transcrição STAT3 , Abietanos/farmacologia , Proliferação de Células , Células Cultivadas , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Humanos , Interleucina-6/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Material Particulado/toxicidade , Fator de Transcrição STAT3/metabolismo
11.
Molecules ; 27(22)2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-36432162

RESUMO

There is an on-going demand in recent years for safer and "greener" hair coloring agents with the global consumer awareness of the adverse effects of synthetic hair dyes. The belief in sustainability and health benefits has focused the attention of the scientific community towards natural colorants that serve to replace their synthetic toxic counterparts. This review article encompasses the historical applications of a vast array of natural plant hair dyes and summarizes the possible coloration mechanisms (direct dyeing and mordant dyeing). Current information on phytochemicals (quinones, tannins, flavonoids, indigo, curcuminoids and carotenoids) used for hair dyeing are summarized, including their botanical sources, color chemistry and biological/toxicological activities. A particular focus is given on research into new natural hair dye sources along with eco-friendly, robust and cost-effective technologies for their processing and applications, such as the synthetic biology approach for colorant production, encapsulation techniques for stabilization and the development of inorganic nanocarriers. In addition, innovative in vitro approaches for the toxicological assessments of natural hair dye cosmetics are highlighted.


Assuntos
Cosméticos , Tinturas para Cabelo , Plantas , Carotenoides , Taninos
12.
AAPS PharmSciTech ; 23(1): 50, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34993683

RESUMO

Inhalation is a promising and challenging method in pharmaceutical and biological science research. A stable environment is critical in dynamic inhalation administration. However, the establishment of a stable inhalation system is very challenging. Indacaterol glycopyrronium bromide inhalation powder (IM/GP mixed powder) is composed of indacaterol maleate and glycopyrronium bromide powder to treat chronic obstructive pulmonary disease (COPD). The aim of this study is to build suitable inhalation conditions and then to evaluate the pulmonary safety of this drug in Sprague-Dawley(SD) rats. In the research, through the coordination of the atomization flow, air pump flow, and scraper speed, aerosols were stabilized at 200 ± 20% mg/m3, and then rats were nose-only administered with the IM/GP mixed powder, Ultibro, and lactose-magnesium stearate mixed powder at 2.6 mg/kg/day for 14 days and 14 days of recovery period, respectively. After exposure, hematology, inflammatory cytokines in rats bronchoalveolar lavage fluid (BALF) and serum, histopathological examination were performed. Results showed that the stability of powder aerosols can be realized under the atomization generation flow: 10 L/min, sampling flow: 2 L/min, system pumping capacity: 10 L/min and powder scraper speed: 8-10 L/min, and there were no significant adverse effects on body weight, clinic signs, hematology, and pathology in rats. Overall, the results suggested that the IM/GP mixed powder inhalation at the dose of 2.6 mg/kg/d can be reached when the aerosol concentration is within the range of 200 ± 20% mg/m3, and there were no pulmonary toxicity effects in rats.


Assuntos
Exposição por Inalação , Roedores , Administração por Inalação , Aerossóis , Animais , Glicopirrolato , Pulmão , Ratos , Ratos Sprague-Dawley
13.
Environ Sci Technol ; 55(10): 7044-7051, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-33914501

RESUMO

The potential of oxygenating Fe(II)-bearing sediments for hydroxyl radical (·OH) production and contaminant degradation has been proposed recently. Here, we further show that specific ligands can largely enhance contaminant degradation during sediment oxygenation due to increased utilization efficiency of sediment electrons. With the addition of 0-2 mM sodium ethylene diamine tetraacetate (EDTA) or sodium tripolyphosphate (TPP) in sediment suspension (50 g/L, pH 7.0), trichloroethylene (TCE, 15 µM) degradation increased from 13% without ligand to a maximum of 80% with 2 mM TPP and was much higher with TPP than EDTA because EDTA competes for ·OH. Electron utilization efficiency for ·OH production increased with increased ligand concentration and was enhanced by up to 6-7 times with 2 mM EDTA or TPP. Electron transfer from sediment to dissolved Fe(III)-ligand is mainly accountable for the enhanced electron utilization efficiency by the ligands with low adsorption affinity (i.e., EDTA), and additional variation of sediment surface Fe(II) coordination is mainly responsible for the enhancement by the ligands with high adsorption affinity (i.e., TPP). Output of this study provides guidance and optional strategies for enhancing contaminant degradation during sediment oxygenation.


Assuntos
Tricloroetileno , Elétrons , Compostos Férricos , Ligantes , Oxirredução
14.
J Sep Sci ; 44(5): 973-980, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33351272

RESUMO

Preparative liquid chromatography has become an important purification method owing to its advantages of high separation efficiency, good reproducibility, and low solvent consumption. Because overloading in preparative liquid chromatography must be performed to increase the throughput in a cycle, nonlinear chromatographic behavior is observed. Therefore, it is crucial to carefully study nonlinear chromatography for the purification of a given product, which facilitates the efficient optimization of the purification parameters. In this work, a method for the development of a purification method using preparative liquid chromatography based on nonlinear chromatography is proposed. Hydroxytyrosol was selected as the subject for method demonstration. Using methanol and ethanol as organic modifiers, the optimum flow rate was determined on three commercial columns entitled C8 TDE, C18 ME, and C18 TDE, respectively. The curves were fitted with the van Deemter equation, with thorough analysis of the A, B, and C terms. Adsorption isotherms were subsequently studied to explore the distribution of solutes between the stationary and mobile phases at equilibrium. C18 TDE, 5 vol% ethanol-water, and 0.2 mL/min were selected as the optimal separation material, elution solvent, and flow rate, respectively. Purification of hydroxytyrosol was tentatively confirmed on a C18 TDE column with 1.6% sample loading, 90.98% recovery, and 98.01% purity.

15.
J Clin Lab Anal ; 35(8): e23817, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34114685

RESUMO

BACKGROUND: Doxorubicin is a first-line chemotherapy agent on human myelogenous leukemia clinical treatment, but the development of chemoresistance has largely limited curative effect. In this study, we aimed to evaluate the biological function and molecular mechanisms of CrkL to Doxorubicin resistance. METHODS: Quantitative reverse transcription-PCR (qRT-PCR) assay was performed to examine the expression of CrkL in K562 and K562/ADR cells. The expression of CrkL was silenced through RNA interference technology. MTT assay and flow cytometry were performed to detect the proliferation inhibition and apoptosis rate after CrkL siRNA transfection. The protein expression changes of PI3K/AKT/MRP1 pathway induced by CrkL siRNA were observed by Western Blot assay. Xenograft tumor model was carried out to observe tumor growth in vivo. RESULTS: We observed that silencing of CrkL could effectively increase apoptosis rate induced by doxorubicin and dramatically reversed doxorubicin resistance in K562/ADR cells. Further studies revealed knockdown CrkL expression suppressed PI3K/Akt/MRP1 signaling, which indicated CrkL siRNA reversed doxorubicin effect through regulating PI3K/Akt/MRP1 pathway. In addition, overexpression of MRP1 could evidently reduce apoptosis rate and reversed the inhibitory effects of doxorubicin resistance caused by CrkL siRNA on K562/ADR cells. Finally, in vivo experiments revealed that CrkL silencing acted a tumor-suppressing role in myelogenous leukemia via regulating PI3K/Akt/MRP1 signaling. CONCLUSION: Together, we indicated that CrkL is up-regulated in myelogenous leukemia cells and silencing of CrkL could reverse Doxorubicin resistance effectively. These results show a potential novel strategy for intervention chemoresistance in myelogenous leukemia during chemotherapy.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Animais , Antibióticos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Humanos , Células K562 , Camundongos Nus , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Environ Sci Technol ; 54(5): 2975-2984, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32023045

RESUMO

It has been documented that contaminants could be degraded by hydroxyl radicals (•OH) produced upon oxygenation of Fe(II)-bearing sediments. However, the dependence of contaminant degradation on sediment characteristics, particularly Fe(II) species, remains elusive. Here we assessed the impact of the abundance of Fe(II) species in sediments on contaminant degradation by •OH during oxygenation. Three natural sediments with different Fe(II) contents and species were oxygenated. During 10 h oxygenation of 200 g/L sediment suspension, 2 mg/L phenol was negligibly degraded for sandbeach sediment (Fe(II): 9.11 mg/g), but was degraded by 41% and 52% for lakeshore (Fe(II): 9.81 mg/g) and farmland (Fe(II): 19.05 mg/g) sediments, respectively. •OH produced from Fe(II) oxygenation was the key reactive oxidant. Sequential extractions, X-ray diffraction, Mössbauer, and X-ray absorption spectroscopy suggest that surface-adsorbed Fe(II) and mineral structural Fe(II) contributed predominantly to •OH production and phenol degradation. Control experiments with specific Fe(II) species and coordination structure analysis collectively suggest the likely rule that Fe(II) oxidation rate and its competition for •OH increase with the increase in electron-donating ability of the atoms (i.e., O) complexed to Fe(II), while the •OH yield decreases accordingly. The Fe(II) species with a moderate oxidation rate and •OH yield is most favorable for contaminant degradation.


Assuntos
Radical Hidroxila , Minerais , Compostos Ferrosos , Oxirredução , Fenol
17.
J Med Internet Res ; 22(12): e23696, 2020 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-33302256

RESUMO

BACKGROUND: Considerable research has been devoted to examining the mental health conditions of patients with COVID-19 and medical staff attending to these patients during the COVID-19 pandemic. However, there are few insights concerning how the pandemic may take a toll on the mental health of the general population, and especially of nonpatients (ie, individuals who have not contracted COVID-19). OBJECTIVE: This study aimed to investigate the association between social media use and mental health conditions in the general population based on a national representative sample during the peak of the COVID-19 outbreak in China. METHODS: We formed a national representative sample (N=2185) comprising participants from 30 provinces across China, who were the first to experience the COVID-19 outbreak in the world. We administered a web-based survey to these participants to analyze social media use, health information support received via social media, and possible psychiatric disorders, including secondary traumatic stress (STS) and vicarious trauma (VT). RESULTS: Social media use did not cause mental health issues, but it mediated the levels of traumatic emotions among nonpatients. Participants received health information support via social media, but excessive social media use led to elevated levels of stress (ß=.175; P<.001), anxiety (ß=.224; P<.001), depression (ß=.201; P<.001), STS (ß=.307; P<.001), and VT (ß=.688; P<.001). Geographic location (or geolocation) and lockdown conditions also contributed to more instances of traumatic disorders. Participants living in big cities were more stressed than those living in rural areas (P=.02). Furthermore, participants from small cities or towns were more anxious (P=.01), stressed (P<.001), and depressed (P=.008) than those from rural areas. Obtaining more informational support (ß=.165; P<.001) and emotional support (ß=.144; P<.001) via social media increased their VT levels. Peer support received via social media increased both VT (ß=.332; P<.001) and STS (ß=.130; P<.001) levels. Moreover, geolocation moderated the relationships between emotional support on social media and VT (F2=3.549; P=.029) and the association between peer support and STS (F2=5.059; P=.006). Geolocation also interacted with health information support in predicting STS (F2=5.093; P=.006). CONCLUSIONS: COVID-19 has taken a severe toll on the mental health of the general population, including individuals who have no history of psychiatric disorders or coronavirus infection. This study contributes to the literature by establishing the association between social media use and psychiatric disorders among the general public during the COVID-19 outbreak. The study findings suggest that the causes of such psychiatric disorders are complex and multifactorial, and social media use is a potential factor. The findings also highlight the experiences of people in China and can help global citizens and health policymakers to mitigate the effects of psychiatric disorders during this and other public health crises, which should be regarded as a key component of a global pandemic response.


Assuntos
Ansiedade/epidemiologia , COVID-19/epidemiologia , Saúde Mental/estatística & dados numéricos , Mídias Sociais/estatística & dados numéricos , Inquéritos e Questionários , Adulto , COVID-19/psicologia , China/epidemiologia , Depressão/epidemiologia , Surtos de Doenças , Feminino , Humanos , Masculino , Pandemias , Estresse Psicológico/epidemiologia
19.
Nano Lett ; 18(9): 5954-5960, 2018 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-30102049

RESUMO

Because of inefficient charge utilization caused by localized π-electron conjugation and large exciton binding energy, the photoelectrochemical water-splitting efficiency of organic polymers is seriously limited. Taking the graphitic carbon nitride (g-CN) polymer as an example, we report a novel photoanode based on a vertically aligned g-CN porous nanorod (PNR) array prepared in situ, using a thermal polycondensation approach, with anodic aluminum oxide as the template. The g-CN PNR array exhibits an excellent photocurrent density of 120.5 µA cm-2 at 1.23 VRHE under one sun illumination, the highest reported incident photon-to-current efficiency of ∼15% at 360 nm, and an outstanding oxygen evolution reaction stability in 0.1 M Na2SO4 aqueous solution, which constitutes a benchmark performance among the reported g-CN-based polymer photoanodes without any sacrificial reagents. When compared with its planar counterpart, the enhanced performance of the PNR array results principally from its unique structure that enables a high degree of aromatic ring π-electron conjugation for higher mobility of charge carriers, provides a direct pathway for the electron transport to the substrate, produces a large portion of hole-accepting defect sites and space charge region to promote exciton dissociation, and also withstands more strain at the interface to ensure intimate contact with the substrate. This work opens a new avenue to develop nanostructured organic semiconductors for large-scale application of solar energy conversion devices.

20.
Phys Chem Chem Phys ; 20(9): 6431-6439, 2018 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-29443336

RESUMO

Graphite oxide powder was obtained using the modified Hummers' method and characterized using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The XPS results indicated that the epoxy groups were the main functional groups on the graphite oxide powder surface. The graphite oxide powder was then reacted with SO2 and NH3 gases, respectively, at 25 °C. The XPS and ToF-SIMS analyses of the surface of the reacted graphite oxide powder showed that the reactions mainly occurred in the epoxy groups. Bisulfate and amine groups were formed on the surface of the graphite oxide powder after the reactions between the graphite oxide powder and SO2 and NH3 gases. This work demonstrates a new method of removing SO2 and NH3 gases using graphite oxide powder.

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