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1.
Dalton Trans ; 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34636393

RESUMO

A T-Nb2O5/CNT nanohybrid with short transmission paths, many active sites, and favorable mechanical flexibility can achieve the fast transportation of ions/electrons. The obtained nanohybrid with continuous conductive networks exhibited better lithium storage performance than sodium storage performance, due to lower resistance to the diffusion of Li+ ions crossing the carbon matrix.

2.
JMIR Mhealth Uhealth ; 9(9): e24402, 2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34473067

RESUMO

BACKGROUND: For rehabilitation training systems, it is essential to automatically record and recognize exercises, especially when more than one type of exercise is performed without a predefined sequence. Most motion recognition methods are based on feature engineering and machine learning algorithms. Time-domain and frequency-domain features are extracted from original time series data collected by sensor nodes. For high-dimensional data, feature selection plays an important role in improving the performance of motion recognition. Existing feature selection methods can be categorized into filter and wrapper methods. Wrapper methods usually achieve better performance than filter methods; however, in most cases, they are computationally intensive, and the feature subset obtained is usually optimized only for the specific learning algorithm. OBJECTIVE: This study aimed to provide a feature selection method for motion recognition of upper-limb exercises and improve the recognition performance. METHODS: Motion data from 5 types of upper-limb exercises performed by 21 participants were collected by a customized inertial measurement unit (IMU) node. A total of 60 time-domain and frequency-domain features were extracted from the original sensor data. A hybrid feature selection method by combining filter and wrapper methods (FESCOM) was proposed to eliminate irrelevant features for motion recognition of upper-limb exercises. In the filter stage, candidate features were first selected from the original feature set according to the significance for motion recognition. In the wrapper stage, k-nearest neighbors (kNN), Naïve Bayes (NB), and random forest (RF) were evaluated as the wrapping components to further refine the features from the candidate feature set. The performance of the proposed FESCOM method was verified using experiments on motion recognition of upper-limb exercises and compared with the traditional wrapper method. RESULTS: Using kNN, NB, and RF as the wrapping components, the classification error rates of the proposed FESCOM method were 1.7%, 8.9%, and 7.4%, respectively, and the feature selection time in each iteration was 13 seconds, 71 seconds, and 541 seconds, respectively. CONCLUSIONS: The experimental results demonstrated that, in the case of 5 motion types performed by 21 healthy participants, the proposed FESCOM method using kNN and NB as the wrapping components achieved better recognition performance than the traditional wrapper method. The FESCOM method dramatically reduces the search time in the feature selection process. The results also demonstrated that the optimal number of features depends on the classifier. This approach serves to improve feature selection and classification algorithm selection for upper-limb motion recognition based on wearable sensor data, which can be extended to motion recognition of more motion types and participants.

3.
Chemosphere ; 287(Pt 1): 132034, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34526272

RESUMO

Soil bacteria could be one of the important sources for ambient HONO. However, the HONO emission from soil bacteria over North China Plain (NCP) with vast croplands has not yet been evaluated. In this study, high-resolution simulations are created to explore the HONO emission from soil bacteria over NCP and related influences on atmospheric chemistry. Ground measurements of critical air pollutants including O3, HONO, and PM2.5 compositions are incorporated to constrain the model simulations. Results show that abundant HONO is emitted from soil bacteria over NCP during summertime and the emission rate varies dramatically for different areas (about 0.2 kg km-2 d-1 - 2.0 kg km-2 d-1). The HONO emission rate presents clear diurnal cycles with peaks of 1.5 kg km-2 d-1 in the afternoon and valleys of 0.4 kg km-2 d-1 during the early morning hours. The resulting HONO concentration ranges from 0.2 µg m-3 to 1.4 µg m-3, which predominates the total HONO concentration in ambient air, particularly in western NCP. The soil bacteria source can significantly alter the diurnal cycles of ambient HONO and OH concentrations over NCP, but only slightly change O3 and PM2.5 concentrations via participating photochemistry and secondary aerosol formations. These results highlight the pressing need for the involvement of HONO emission from soil bacteria in modeling studies regarding atmospheric chemistry, particularly in rural areas.

4.
Nanotechnology ; 32(50)2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34404036

RESUMO

Increasing the specific surface area and the amount of doping heteroatoms is an effective means to improve the electrochemical properties of carbon nanotubes (CNTs). The usual activation method makes it difficult for the retention of the heteroatoms while enlarging the specific surface area, and it can be found from literatures that specific surface area and S-content of carbon-based electrode materials are mutually exclusive. Here, CNTs with high specific surface area and sulfur content are constructed by simple activation of sulfonated polymer nanotubes with KHCO3, and the excellent electrochemical performance can be explained by the following points: first, KHCO3can be decomposed into K2CO3, CO2and H2O during the activation process. The synergistic action of physical activation (CO2and H2O) and chemical activation (K2CO3) equips the electrode material with high specific surface area of 1840 m2g-1and hierarchical micro/mesopores, which is beneficial to its double-layer capacitance. Second, compared with reported porous CNTs prepared by chemical activation (KOH) or physical activation (CO2or H2O), the mild activator KHCO3makes the sulfur content at a high level of 4.6 at%, which is very advantageous for high pseudocapacitance performance.

5.
Sci Total Environ ; 799: 149426, 2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34371396

RESUMO

Urban expansion not only results in land use transformation, but also introduces extra anthropogenic emissions over the expanded urban areas, which is usually neglected in existing studies. In this study, we consider both the changes in land use categories and added anthropogenic emissions from 2001 to 2018 in the Yangtze River Delta (YRD) which we define as the city of Shanghai and the nearby provinces of Zhejiang, Jiangsu, and Anhui, China and explore the individual and combined impacts of these factors on air pollution using the WRF-Chem model. Calibrated by available observations, the model performs well (IOA (index of agreement) > 0.8) in reproducing the meteorological fields and ambient PM2.5 and O3 concentrations in September 2018. We show that the land use transformation from non-urban to urban and the introduced anthropogenic emissions over new urban areas exert opposite influences on ambient PM2.5 concentrations over YRD, particularly in the expanded urban areas, and the PM2.5 decrease due to land use changes is significantly offset by the increase due to added emissions. The response of ambient O3 concentration to these two factors is highly variable in space, which is dependent on the chemical regime of tropospheric O3 formation and influenced by the chemistry-meteorology feedback. As the total effect, strong increases in O3 concentration occur over the central areas of YRD. These results highlight that it is essential to take into account the additional anthropogenic emissions over expanded urban areas in the assessment of environmental impacts of urban expansion.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Monitoramento Ambiental , Material Particulado/análise , Rios , Estações do Ano
6.
Plant Cell Physiol ; 2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34255851

RESUMO

Pogostone, a compound with various pharmaceutical activities, is a major constituent of the essential oil preparation called Pogostemonis Herba, which is obtained from the plant Pogostemon cablin. The biosynthesis of pogostone has not been elucidated, but 4-methylvaleryl-CoA (4MVCoA) is a likely precursor. We analyzed the distribution of pogostone in P. cablin using gas chromatography-mass spectrometry (GC-MS) and found that pogostone accumulates at high levels in main stems and leaves of young plants. A search for the acyl-activating enzyme (AAE) that catalyzes the formation of 4MVCoA from 4-methylvaleric acid was launched, using an RNAseq-based approach to identify 31 unigenes encoding putative AAEs including the PcAAE2, the transcript profile of which shows a strong positive correlation with the distribution pattern of pogostone. The protein encoded by PcAAE2 was biochemically characterized in vitro and shown to catalyze the formation of 4MVCoA from 4-methylvaleric acid. Phylogenetic analysis showed that PcAAE2 is closely related to other AAE proteins in P. cablin and other species that are localized to the peroxisomes. However, PcAAE2 lacks a peroxisome targeting sequence 1 (PTS1) and is localized in the cytosol.

7.
Sci Total Environ ; 797: 148876, 2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34311358

RESUMO

Heavy haze with high levels of fine particulate matters (PM2.5) frequently engulfs the Guanzhong Basin (GZB) in northwestern China during wintertime. Although it is an enclosed basin with a narrow opening to the east, prevailing easterly winds during heavy haze episodes have a large potential to bring air pollutants to the GZB from the two highly polluted neighboring provinces of Shanxi and Henan (SX&HN). The source-oriented WRF-Chem model simulations of a persistent and heavy haze episode that occurred in the GZB from December 6 to 21, 2016, reveal that local emissions dominate PM2.5 concentrations in the GZB, with an average near-surface PM2.5 contribution of about 56.0% during the episode. The transboundary transport of emissions from SX&HN accounts for around 22.2% of the total PM2.5 in the GZB. Furthermore, with the deterioration of the air quality in the GZB from being slightly polluted to severely polluted in terms of hourly PM2.5 concentration, transboundary transport of emissions from SX&HN plays an increasingly important role in the particulate pollution, with the average PM2.5 contribution increasing from 8.0% to 27.5%. Compared with the source-oriented method (SOM), the brute force method (BFM) overestimates the contribution of GZB local emissions and transboundary transport of emissions from SX&HN to the total PM2.5 in the GZB. In addition, the BFM-estimated NH3 contribution of transboundary transport of emissions from SX&HN is negative, indicating the limitation of the BFM in source apportionment. Our results suggest that cooperative emission mitigation strategies with neighboring provinces are beneficial for lowering the particulate pollution in the GZB, particularly under severely polluted conditions.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Monitoramento Ambiental , Material Particulado/análise , Estações do Ano
8.
Environ Pollut ; 288: 117712, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34246996

RESUMO

Nitrate, as one of the major components of tropospheric aerosols, plays a crucial role in winter haze formation. While, the formation mechanism of the high production of nitrate in Chinese megacities is still not fully understood. To quantify the contributions of major formation pathways to nitrate, airborne particles in Xi'an, inland China during the winter of 2017 were measured and analyzed for the water-soluble ions and stable nitrogen/oxygen isotope compositions of nitrate in PM2.5, followed by a WRF-Chem model simulation. The oxygen isotopic results indicated that N2O5 hydrolysis was an important formation pathway for the daytime nitrate in the haze episodes. The model simulation further revealed that N2O5 hydrolysis contribution increased from 8.2% to 20.5% of the total nitrate over 14:00-16:00 p.m., clearly showing that N2O5 formation followed by a heterogeneous hydrolysis to nitrate can effectively proceed in daytime under the abundantly co-existing O3, NO2 and NH3 conditions.


Assuntos
Poluentes Atmosféricos , Nitratos , Aerossóis/análise , Poluentes Atmosféricos/análise , China , Monitoramento Ambiental , Hidrólise , Nitratos/análise , Material Particulado/análise , Estações do Ano
9.
Carbohydr Polym ; 269: 118355, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34294357

RESUMO

In this paper, N-methylene phosphonic acid chitosan (NPCS-PEI) was synthesized from chitosan, phosphorous acid, formaldehyde and hyperbranched polyethyleneimine (PEI), and Cu2+ and Pb2+ removal performance was examined in aqueous solution. NPCS-PEI exhibited three-dimensional porous architectures, with a specific surface area of 490.61 m2/g. The effects of pH, initial concentration, adsorption time, temperature and ionic strength on the adsorption capacity were investigated. The adsorption kinetics indicated that Cu2+ and Pb2+ adsorption onto NPCS-PEI follows a pseudo-second-order model. The adsorption isotherms agree well with the Langmuir isotherm model, and the maximum adsorption capacities of Cu2+ and Pb2+ on the NPCS-PEI are approximately 276.12 and 645.16 mg/g, respectively. The adsorption efficiency of NPCS-PEI remained above 85% after 5 adsorption-desorption successive cycles. Moreover, the NPCS-PEI aerogels had selective adsorption toward Cu2+. The FTIR and XPS analysis proved that amino, hydroxyl, and phosphonic acid groups were involved in the chelation with metal ions.

10.
Bull Environ Contam Toxicol ; 107(2): 239-247, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34100970

RESUMO

Pydiflumetofen is a new succinate dehydrogenase inhibitor fungicide, and the method for determination of its residues in rice and associated environmental samples has not yet been reported. Here, we optimized, Quick Easy, Cheap, Effective, Rugged, Safe (QuEChERS) method for sample preparation, and used high performance liquid chromatography-tandem mass spectrometry (HPLC-MS) to detect the residual amounts of pydiflumetofen in rice and its environment. The results showed that there was a good linearity over the pydiflumetofen concentration range of 0.01-0.1 mg/L in all matrices (R2 > 0.99). At the spiked levels of 0.01, 0.05, and 0.1 mg/kg, the recovery rates of pydiflumetofen from various matrices were between 84.23 and 105.10 %, with the relative standard deviation of 1.07-9.99 %. The limit of detection (signal-to-noise ratio = 3) of the proposed method for pydiflumetofen was in the range of 1.9-3.5 µg/kg, and the limit of quantification (signal-to-noise ratio = 10) was in the range of 6.3-11.7 µg/kg.


Assuntos
Oryza , Resíduos de Praguicidas , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Resíduos de Praguicidas/análise , Pirazóis , Espectrometria de Massas em Tandem
11.
Nanoscale ; 13(23): 10320-10328, 2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-33988212

RESUMO

The shuttle effect derived from the dissolution of lithium polysulfides (LIPs) seriously hinders commercialization of lithium-sulfur (Li-S) batteries. Hence, we skillfully designed 1D cowpea-like CNTs@Bi composites with a double adsorption structure, where the bismuth nanoparticles/nanorods are encapsulated in the cavities of CNTs, avoiding the aggregation of bismuth nanoparticles during cycling and improving the conductivity of the electrode. Meanwhile, the sulfur was evenly distributed on the surface of bismuth nanoparticles/nanorods, ensuring effective catalytic activity and displaying high sulfur loading. Under the synergetic effects of the physical detention of abundant pores and chemical adsorption of bismuth, LIPs can be minimised, effectively curbing the shuttle effect. Benefiting from the above advantages, the CNTs@Bi/S cathodes exhibit a high capacity of 1352 mA h g-1, long cycling lifespan (708 mA h g-1 after 200 cycles at 1 C) and excellent coulombic efficiency. As the anodes of lithium-ion batteries (LIBs), the CNTs@Bi composites also show excellent performance due to the encapsulated structure to accommodate the serious volume change. This work offers an innovative strategy for improving the performances of the Li-S batteries and LIBs.

12.
Aging (Albany NY) ; 13(10): 13680-13692, 2021 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-33902003

RESUMO

BACKGROUND AND PURPOSE: Rapidly recognizing patients with large-vessel occlusion stroke (LVOS) and transferring them to a center offering recanalization therapy is crucial of maximizing the benefits of early treatment. We therefore aimed to design an easy-to-use recognition instrument for identifying LVOS. METHODS: Prospective data were collected from emergency departments of 12 stroke-center hospitals in China during a 17-month study period. The Stroke Aid for Emergency (SAFE) scale is based on consciousness commands, facial palsy, gaze, and arm motor ability. Receiver operating characteristic analysis was used to obtain the area under the curve for the SAFE scale and previously established scales to predict LVOS. RESULTS: The SAFE scale could accurately predict LVOS at an accuracy rate comparable to that of the National Institutes of Health Stroke Scale (c-statistics: 0.823 versus 0.831, p = 0.4798). The sensitivity, specificity, positive predictive value, and negative predictive value for the SAFE scale were 0.6875, 0.8577, 0.6937, and 0.8542, respectively, with a cutoff point of 4. The SAFE scale also performed well in a subgroup analysis based on the patients' ages, occluded vessel locations, and the onset-to-door times. CONCLUSIONS: The SAFE scale can accurately recognize LVOS at a rate comparable to those of other, similar scales.


Assuntos
Arteriopatias Oclusivas/diagnóstico , Serviço Hospitalar de Emergência , Acidente Vascular Cerebral/diagnóstico , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Curva ROC , Reprodutibilidade dos Testes
13.
J Cell Mol Med ; 25(9): 4466-4477, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33834616

RESUMO

Macrophages play a key role in silicosis, and exosomes are potent mediators of intercellular communication. This suggests that macrophage-derived exosomes have a potential contribution to the pathogenesis of silicosis. To investigate whether macrophage-derived exosomes promote or inhibit lung fibrosis, in vitro, silica-exposed macrophage-derived exosomes (SiO2 -Exos) were collected and cocultured with fibroblasts. The expression of collagen I and α-SMA was evaluated. Furthermore, the endoplasmic reticulum (ER) stress markers BIP, XBP1s and P-eIF2α were assessed after treatment with or without the ER stress inhibitor 4-PBA. In vivo, mice were pre-treated with the exosome secretion inhibitor GW4869 prior to silica exposure. After sacrifice, lung tissues were histologically examined, and the expression of proinflammatory cytokines (TNF-α, IL-1ß and IL-6) in bronchoalveolar lavage fluid (BALF) was measured. The results showed that the expression of collagen I and α-SMA was up-regulated after treatment with SiO2 -Exos, accompanied by increased expression of BIP, XBP1s and P-eIF2α. Pre-treatment with 4-PBA reversed this effect. More importantly, an in vivo study demonstrated that pre-treatment with GW4869 decreased lung fibrosis and the expression of TNF-α, IL-1ß and IL-6 in BALF. These results suggested that SiO2 -Exos are profibrogenic and that the facilitating effect is dependent on ER stress.


Assuntos
Estresse do Retículo Endoplasmático , Exossomos/fisiologia , Fibroblastos/patologia , Macrófagos/fisiologia , Fibrose Pulmonar/patologia , Dióxido de Silício/toxicidade , Silicose/patologia , Animais , Comunicação Celular , Citocinas , Fibroblastos/metabolismo , Macrófagos/citologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fibrose Pulmonar/etiologia , Fibrose Pulmonar/metabolismo , Transdução de Sinais , Silicose/etiologia , Silicose/metabolismo
14.
Sci Rep ; 11(1): 7752, 2021 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-33833340

RESUMO

To explore the clinical application value of chest CT quantitative pulmonary inflammation index (PII) in the evaluation of the course and treatment outcome of COVID-19 pneumonia. One hundred and eighteen patients with COVID-19 pneumonia diagnosed by RT-PCR were analyzed retrospectively. The correlation between chest CT PII, clinical symptoms and laboratory examinations during the entire hospitalization period was compared. The average age of the patients was 46.0 ± 15 (range: 1-74) years. Of the 118 patients, 62 are male (52.5%) and 56 are female (47.5%). Among them, 116 patients recovered and were discharged, 2 patients died, and the median length of hospital stay was 22 (range: 9-41) days. On admission, 76.3% of the patients presented with fever, and the laboratory studies showed a decrease in lymphocyte (LYM) count and an increase in lactate dehydrogenase (LDH) levels, C-reactive protein (CRP) levels, and erythrocyte sedimentation rate (ESR). Within the studies' chest CTs, the median number of involved lung lobes was 4 (range: 0-5) and the median number of involved lung segments was 9 (range 0-20). The left lower lobe and the right lower lobe were the most likely areas to be involved (89.0% and 83.9%), and 84.7% of the patients had inflammatory changes in both lungs. The main manifestations on chest CT were ground glass opacities (31.4%), ground glass opacities and consolidation (20.3%), ground glass opacities and reticular patterns (32.2%), mixed type (13.6%), and white lungs (1.7%); common accompanying signs included linear opacities (55.9%), air bronchograms (46.6%), thick small vessel shadows (36.4%), and pleural hypertrophy (13.6%). The chest CT at discharge showed complete absorption of lesions in 19 cases (16.1%), but not in the remaining 99 cases. Lesions remained in a median of 3 lung lobes (range: 0-5). Residual lesions remained in a median of 5 lung segments (range: 0-20). The residual lesions mainly presented as ground glass opacities (61.0%), and the main accompanying sign was linear opacities (59.3%). Based on chest CT, the median maximum PII of lungs was 30.0% (range: 0-97.5%), and the median PII after discharge in the patients excluding the two deaths was 12.5% (range: 0-53.0%). PII was significantly negatively correlated with the LYM count and significantly positively correlated with body temperature, LDH, CRP, and ESR. There was no significant correlation between the PII and the white blood cell count, but the grade of PII correlated well with the clinical classification. PII can be used to monitor the severity and the treatment outcome of COVID-19 pneumonia, provide help for clinical classification, assist in treatment plan adjustments and aid assessments for discharge.


Assuntos
COVID-19/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Tórax/diagnóstico por imagem , Adolescente , Adulto , Idoso , COVID-19/terapia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , SARS-CoV-2/isolamento & purificação , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Adulto Jovem
15.
Biochem Biophys Res Commun ; 554: 25-32, 2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-33774276

RESUMO

Osteosarcoma, a highly aggressive malignant tumor of the bone, usually occurs in children and young adults. However, although the considerable achievement in the clinical treatment of osteosarcoma recent years, the overall survival of osteosarcoma patients has not been obviously improved. Cancer cells preferentially use glycolysis instead of oxidative phosphorylation to meet their increased energetic and biosynthetic demands, a phenomenon known as the Warburg effect. Glycolysis is a driving factor in multiple cancers and is emerging as a new cancer target treatment. In the present study, we established a model to screen for glycolysis-associated genes in osteosarcoma. This risk score of the model were correlated with clinical characteristics osteosarcoma patients. Besides, a functional assay identified that STC2 enhanced the glycolysis of osteosarcoma cells. Modulation of STC2 changes glucose consumption and lactate production as well as GLUT1 expression in osteosarcoma. Furthermore, we identified that change in the expression levels of STC2 affected the proliferation, invasion, and migration of osteosarcoma cells. Our findings showed STC2 as a new tumor-promoting factor of osteosarcoma cells through enhancing glycolysis.


Assuntos
Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Glucose/metabolismo , Glicoproteínas/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Ácido Láctico/metabolismo , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Neoplasias Ósseas/genética , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Biologia Computacional , Bases de Dados Genéticas , Glicólise , Glicoproteínas/genética , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Osteossarcoma/genética , Prognóstico , Taxa de Sobrevida
16.
Environ Pollut ; 279: 116931, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33756242

RESUMO

Stringent mitigation measures have reduced wintertime fine particulate matter (PM2.5) concentrations by 42.2% from 2013 to 2018 in the Beijing-Tianjin-Hebei (BTH) region, but severe PM pollution still frequently engulfs the region. The observed nitrate aerosols have not exhibited a significant decreasing trend and constituted a major fraction (about 20%) of the total PM2.5, although the surface-measured NO2 concentration has decreased by over 20%. The contributions of nitrogen oxides (NOX) emissions mitigation to the nitrate and PM2.5 concentrations and how to alleviate nitrate aerosols efficiently under the current situation still remains elusive. The WRF-Chem model simulations of a persistent and heavy PM pollution episode in January 2019 in the BTH reveal that NOX emissions mitigation does not help lower wintertime nitrate and PM2.5 concentrations under current conditions in the BTH. A 50% reduction in NOX emissions only decreases nitrate mass by 10.3% but increases PM2.5 concentrations by 3.2%, because the substantial O3 increase induced by NOX mitigation offsets the HNO3 loss and enhances sulfate and secondary organic aerosols formation. Our results are further consolidated by the occurrence of severe PM pollution in the BTH during the COVID-19 outbreak, with a significant reduction in NO2 concentration. Mitigation of NH3 emissions constitutes the priority measure to effectively lower the nitrate and PM2.5 concentrations in the BTH under current conditions, with 35.5% and 12.7% decrease, respectively, when NH3 emissions are reduced by 50%.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , COVID-19 , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Poluição do Ar/prevenção & controle , Pequim , China , Monitoramento Ambiental , Humanos , Material Particulado/análise , SARS-CoV-2
17.
ACS Appl Mater Interfaces ; 13(12): 14507-14517, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33733727

RESUMO

The self-assembly of block copolymers in a confined space has been proven to be a facile and robust strategy for fabricating assembled structures with various potential applications. Herein, we employed a new pH-responsive polymer self-assembly method to regulate ion transport inside artificial nanochannels. The track-etched asymmetric nanochannels were functionalized with PS22k-b-P4VP17k/hPS4k blend polymers, and the ionic conductance and rectification properties of the proposed system were investigated. The pH-actuated changes in the surface charge and wettability resulted in the selective pH-gated ionic transport behavior. The designed system showed a good switching property to the pH stimulus and could recover during the repetitive experiments. The gating ability of the polymer-nanochannel system increased with increasing the weight of the homopolymer, and the proposed platform demonstrated robust stability and reusability. Numerical and the dissipative particle dynamics simulations were implemented to emulate the pH-dependent self-assembling behavior of diblock copolymers in a confined space, which were consistent with the experimental observations. As an example of the self-assembly of polymers in nanoconfinements, this work provides a facile and robust strategy for the regulation of ion transport in synthetic nanochannels. Meanwhile, this work can be further extended to design artificial smart nanogates for various applications such as mass delivery and energy harvesting.

18.
Mol Plant ; 14(5): 722-731, 2021 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-33631420

RESUMO

Recently reported adenine base editors (ABEs) exhibit powerful potential for targeted gene correction as well as developing gain-of-function mutants and novel germplasms for both gene function studies and crop breeding. However, editing efficiency varies significantly among different target sites. Here, we investigated the activities of three evolved E. coli adenosine deaminase TadA variants (TadA8e, TadA8.17, and TadA8.20) side-by-side in transgenic rice. We found that TadA8e outperforms TadA8.17 and TadA8.20, and induces efficient A-to-G conversion at all tested sites in the rice genome, including those that were uneditable by ABE7.10 in our previous experiments. Furthermore, V82S/Q154R mutations were incorporated into TadA8e, resulting in a new variant that we named TadA9. Our data show that TadA9 is broadly compatible with CRISPR/SpCas9, CRISPR/SpCas9-NG, and CRISPR/SpRY, as well as CRISPR/ScCas9 nickase systems, achieving comparable or enhanced editing in a larger editing window at diverse PAM sites as compared with TadA8e. Finally, TadA9 was used to simultaneously install novel SNPs in four endogenous herbicide target genes in the commercial rice cultivar Nangeng 46 for potential field application in weed control. Collectively, we successfully generated a series of novel ABEs that can efficiently edit adenosines in the rice genome. Our findings suggest that TadA9 and TadA8e have great potentials in the development of plant base editors and crop molecular breeding.

19.
Biol Chem ; 402(2): 207-219, 2021 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-33544468

RESUMO

This study was designed to illustrate the function and role of PCAT1 in CCA. The relative expression was confirmed by RT-qPCR and western blot. The biological function of PCAT1 was evaluated by CCK8, EdU, colony formation, wound healing, transwell, and subcutaneous tumor formation assays. Protein levels of EMT markers were measured by western blot. The binding relationship was predicted by JASPAR and starBase. The binding of YY1 to PCAT1 promoter was assessed by ChIP and luciferase reporter. The binding capacity between miR-216a-3p and PCAT1 as well as BCL3 was assessed by luciferase reporter and AGO2-RIP assays. In this study, we found that PCAT1 was up-regulated in CCA tissues and cells, and the PCAT1 overexpression was associated with poor prognosis. Moreover, PCAT1 was assessed as an independent risk factor of prognosis for CCA patients. Amplified PCAT1 was found to promote tumor proliferation, migration, invasion and EMT process, whereas PCAT1 knockdown inhibited these malignant phenotypes. Mechanistically, PCAT1 was predominantly localized in the cytoplasm and competitively bound miR-216a-3p to increase BCL3 expression. In addition, PCAT1 was activated by transcription factor YY1. This study revealed that PCAT1 acted as an oncogene in CCA, and the YY1/PCAT1/miR-216a-3p/BCL3 axis exhibited critical functions in CCA progression.


Assuntos
Proteína 3 do Linfoma de Células B/metabolismo , Neoplasias dos Ductos Biliares/metabolismo , Colangiocarcinoma/metabolismo , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Regulação para Cima , Fator de Transcrição YY1/metabolismo , Proteína 3 do Linfoma de Células B/genética , Neoplasias dos Ductos Biliares/patologia , Movimento Celular , Proliferação de Células , Células Cultivadas , Colangiocarcinoma/patologia , Feminino , Humanos , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , RNA Longo não Codificante/genética , Fator de Transcrição YY1/genética
20.
Dig Dis Sci ; 2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33570683

RESUMO

BACKGROUND: Long non-coding RNA (lncRNA) has been testified to influence the initiation and evolution of sundry carcinomas. Recently, lncRNA FOXD2 adjacent opposite strand RNA 1 (FOXD2-AS1) has been found to display vital regulating functions in various cancers. METHODS: qRT-PCR was used to verify the dysregulation of FOXD2-AS1 expression in CCA cells and tissues, and the correlation of FOXD2-AS1 expression with clinicopathological characteristics was investigated. The viability, migration, and invasion of CCA cells were verified through CCK-8 assay, colony formation experiment, wound healing assay, and transwell assay. The regulatory networks of FOXD2-AS1 were analyzed by Bioinformatic prediction and dual-luciferase reporter assay. RESULTS: We discovered that FOXD2-AS1 was significantly upregulated in CCA and its up-regulation was closely correlated with terminal TNM stage, lymph node metastasis and poor survival in the current research. In addition, it was revealed that FOXD2-AS1 was an independent prognostic factor. Functional tests uncovered that the cell viability, migration, and invasion could be restrained through downregulating the expression of FOXD2-AS1, while FOXD2-AS1 overexpression could facilitate the cell viability, migration, and invasion. Mechanistically, FOXD2-AS1 was founded to interact directly with miR-760 and the oncogene E2F3 was the downstream target of miR-760 through bioinformatic prediction and dual-luciferase reporter assays. Finally, we testified that FOXD2-AS1 could competitively sponge miR-760 and further upregulated the E2F3 expression to play a vital part in cholangiocarcinoma. CONCLUSIONS: This research revealed that lncRNA FOXD2-AS1 could enhance CCA malignant progression through regulating the miR-760/E2F3 axis and was expected to be a prognostic biomarker and therapeutic target for cholangiocarcinoma.

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