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1.
Sensors (Basel) ; 21(4)2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33546240

RESUMO

The rapid advance and popularization of VoIP (Voice over IP) has also brought security issues. VoIP-based secure voice communication has two sides: first, for legitimate users, the secret voice can be embedded in the carrier and transmitted safely in the channel to prevent privacy leakage and ensure data security; second, for illegal users, the use of VoIP Voice communication hides and transmits illegal information, leading to security incidents. Therefore, in recent years, steganography and steganography analysis based on VoIP have gradually become research hotspots in the field of information security. Steganography and steganalysis based on VoIP can be divided into two categories, depending on where the secret information is embedded: steganography and steganalysis based on voice payload or protocol. The former mainly regards voice payload as the carrier, and steganography or steganalysis is performed with respect to the payload. It can be subdivided into steganography and steganalysis based on FBC (fixed codebook), LPC (linear prediction coefficient), and ACB (adaptive codebook). The latter uses various protocols as the carrier and performs steganography or steganalysis with respect to some fields of the protocol header and the timing of the voice packet. It can be divided into steganography and steganalysis based on the network layer, the transport layer, and the application layer. Recent research results of steganography and steganalysis based on protocol and voice payload are classified in this paper, and the paper also summarizes their characteristics, advantages, and disadvantages. The development direction of future research is analyzed. Therefore, this research can provide good help and guidance for researchers in related fields.

2.
Environ Sci Technol ; 55(4): 2189-2207, 2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33539077

RESUMO

Severe haze events with exceedingly high-levels of fine aerosols occur frequently over the past decades in the North China Plain (NCP), exerting profound impacts on human health, weather, and climate. The development of effective mitigation policies requires a comprehensive understanding of the haze formation mechanisms, including identification and quantification of the sources, formation, and transformation of the aerosol species. Haze evolution in this region exhibits distinct physical and chemical characteristics from clean to polluted periods, as evident from increasing stagnation and relative humidity, but decreasing solar radiation as well as explosive secondary aerosol formation. The latter is attributed to highly elevated concentrations of aerosol precursor gases and is reflected by rapid increases in the particle number and mass concentrations, both corresponding to nonequilibrium chemical processes. Considerable new knowledge has been acquired to understand the processes regulating haze formation, particularly in light of the progress in elucidating the aerosol formation mechanisms. This review synthesizes recent advances in understanding secondary aerosol formation, by highlighting several critical chemical/physical processes, that is, new particle formation and aerosol growth driven by photochemistry and aqueous chemistry as well as the interaction between aerosols and atmospheric stability. Current challenges and future research priorities are also discussed.

3.
J Cell Mol Med ; 2021 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-33621425

RESUMO

MicroRNA-24-3p (miR-24-3p) has been implicated as a key promoter of chemotherapy resistance in numerous cancers. Meanwhile, cancer-associated fibroblasts (CAFs) can secret exosomes to transfer miRNAs, which mediate tumour development. However, little is known regarding the molecular mechanism of CAF-derived exosomal miR-24-3p in colon cancer (CC). Hence, this study intended to characterize the functional relevance of CAF-derived exosomal miR-24-3p in CC cell resistance to methotrexate (MTX). We identified differentially expressed HEPH, CDX2 and miR-24-3p in CC through bioinformatics analyses, and validated their expression in CC tissues and cells. The relationship among HEPH, CDX2 and miR-24-3p was verified using ChIP and dual-luciferase reporter gene assays. Exosomes were isolated from miR-24-3p inhibitor-treated CAFs (CAFs-exo/miR-24-3p inhibitor), which were used in combination with gain-of-function and loss-of-function experiments and MTX treatment. CCK-8, flow cytometry and colony formation assays were conducted to determine cell viability, apoptosis and colony formation, respectively. Based on the findings, CC tissues and cells presented with high expression of miR-24-3p and low expression of HEPH and CDX2. CDX2 was a target gene of miR-24-3p and could up-regulate HEPH. Under MTX treatment, overexpressed CDX2 or HEPH and down-regulated miR-24-3p reduced cell viability and colony formation and elevated cell apoptosis. Furthermore, miR-24-3p was transferred into CC cells via CAF-derived exosomes. CAF-derived exosomal miR-24-3p inhibitor diminished cell viability and colony formation and increased cell apoptosis in vitro and inhibited tumour growth in vivo under MTX treatment. Altogether, CAF-derived exosomal miR-24-3p accelerated resistance of CC cells to MTX by down-regulating CDX2/HEPH axis.

4.
J Cell Mol Med ; 2021 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-33621431

RESUMO

Hepatocellular cancer (HCC) has been reported to belong to one of the highly vascularized solid tumours accompanied with angiogenesis of human umbilical vein endothelial cells (HUVECs). KDM5A, an attractive drug target, plays a critical role in diverse physiological processes. Thus, this study aims to investigate its role in angiogenesis and underlying mechanisms in HCC. ChIP-qPCR was utilized to validate enrichment of H3K4me3 and KDM5A on the promotor region of miR-433, while dual luciferase assay was carried out to confirm the targeting relationship between miR-433 and FXYD3. Scratch assay, transwell assay, Edu assay, pseudo-tube formation assay and mice with xenografted tumours were conducted to investigate the physiological function of KDM5A-miR-433-FXYD3-PI3K-AKT axis in the progression of HCC after loss- and gain-function assays. KDM5A p-p85 and p-AKT were highly expressed but miR-433 was down-regulated in HCC tissues and cell lines. Depletion of KDM5A led to reduced migrative, invasive and proliferative capacities in HCC cells, including growth and a lowered HUVEC angiogenic capacity in vitro. Furthermore, KDM5A suppressed the expression of miR-433 by demethylating H3K4me3 on its promoterregion. miR-433 negatively targeted FXYD3. Depleting miR-433 or re-expressing FXYD3 restores the reduced migrative, invasive and proliferative capacities, and lowers the HUVEC angiogenic capacity caused by silencing KDM5A. Therefore, KDM5A silencing significantly suppresses HCC tumorigenesis in vivo, accompanied with down-regulated miR-433 and up-regulated FXYD3-PI3K-AKT axis in tumour tissues. Lastly, KDM5A activates the FXYD3-PI3K-AKT axis to enhance angiogenesis in HCC by suppressing miR-433.

5.
Vet Microbiol ; 254: 108994, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33486326

RESUMO

Porcine epidemic diarrhea virus (PEDV) encodes many multifunctional proteins that inhibit host innate immune response during virus infection. As one of important structural proteins, PEDV E protein has been found to block the production of type I interferon (IFN) in virus life cycle, but little is known about this process that E protein subverts host innate immune. Thus, in this present study, we initiated the construction of eukaryotic expression vectors to express PEDV E protein. Subsequently, cellular localization analysis was performed and the results showed that the majority of PEDV E protein distributed at cytoplasm and localized in endoplasmic reticulum (ER). Over-expression of PEDV E protein significantly inhibited poly(I:C)-induced IFN-ß and IFN-stimulated genes (ISGs) productions. We also found that PEDV E protein remarkably suppressed the protein expression of RIG-I signaling-associated molecules, but all their corresponding mRNA levels remained unaffected and unchanged. Furthermore, PEDV E protein obviously interfered with the translocation of IRF3 from cytoplasm to nucleus through direct interaction with IRF3, which is crucial for the IFN-ß production induced by poly(I:C). Taken together, our results suggested that PEDV E protein acts as an IFN-ß antagonist through suppression of the RIG-I-mediated signaling. This study will pave the way for the further investigation into the molecular mechanisms by which PEDV E protein evades host innate immune response.

6.
Environ Sci Technol ; 55(2): 832-841, 2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33377762

RESUMO

The phase states of primarily emitted and secondarily formed aerosols from gasoline vehicle exhausts were investigated by quantifying the particle rebound fraction (f). The rebound behaviors of gasoline vehicle emission-related aerosols varied with engines, fuel types, and photochemical aging time, showing distinguished differences from biogenic secondary organic aerosols. The nonliquid-to-liquid phase transition of primary aerosols emitted from port fuel injection (PFI) and gasoline direct injection (GDI) vehicles started at a relative humidity (RH) = 50 and 60%, and liquefaction was accomplished at 60 and 70%, respectively. The RH at which f declined to 0.5 decreased from 70 to 65% for the PFI case with 92# fuel, corresponding to the photochemical aging time from 0.37 to 4.62 days. For the GDI case, such RH enhanced from 60 to 65%. Our results can be used to imply the phase state of traffic-related aerosols and further understand their roles in urban atmospheric chemistry. Taking Beijing, China, as an example, traffic-related aerosols were mainly nonliquid during winter with the majority ambient RH below 50%, whereas they were mostly liquid during the morning rush hour of summer, and traffic-related secondary aerosols fluctuated between nonliquid and liquid during the daytime and tended to be liquid at night with increased ambient RH.

7.
J Environ Sci (China) ; 99: 324-335, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33183711

RESUMO

The hydroxyl radical (•OH) has a crucial function in the oxidation and removal of many atmospheric compounds that are harmful to health. Nevertheless, high reactivity, low atmospheric abundance, determination of hydroxyl, and hydroperoxyl radical's quantity is very difficult. In the atmosphere and troposphere, hydroperoxyl radicals (HO2) are closely demanded in the chemical oxidation of the troposphere. But advances in technology have allowed researchers to improve the determination methods on the research of free radicals through some spectroscopic techniques. So far, several methods such as laser-induced fluorescence (LIF), high-performance liquid chromatography (HPLC), and chemical ionization mass spectroscopy have been identified and mostly used in determining the quantity of hydroxyl and hydroperoxyl radicals. In this systematic review, we have advised the use of scavenger as an advance for further researchers to circumvent some of these problems caused by free radicals. The primary goal of this review is to deepen our understanding of the functions of the most critical free radical (•OH, HO2) and also understand the currently used methods to quantify them in the atmosphere and troposphere.


Assuntos
Atmosfera , Radical Hidroxila , Radicais Livres , Oxirredução
8.
Chemosphere ; 262: 127745, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32805654

RESUMO

Nitrate (NO3-), sulfate (SO42-) and ammonium (NH4+) in airborne fine particles (PM2.5) play a vital role in the formation of heavy air pollution in northern China. In particular, the increasing contribution of NO3- to PM2.5 has attracted worldwide attention. In this study, a highly time-resolved analyzer was used to measure water-soluble inorganic ions in PM2.5 in one of the fastest-developing megacities, Tianjin, China, from November 15 to March 15 (wintertime heating period) in 2014-2019. Severe PM2.5 pollution episodes markedly decreased during the heating period from 2014 to 2019. The highest concentrations of NO3- and SO42- were recorded in the heating period of 2015/2016. Afterwards, NO3- decreased from 2015/2016 (20.2 ± 23.8 µg/m3) to 2017/2018 (11.6 ± 14.8 µg/m3) but increased with increasing NOx concentrations during the heating period of 2018/2019. A continuous decrease in the SO2 concentration led to a decrease in SO42- from 2015/2016 (16.8 ± 21.8 µg/m3) to 2018/2019 (6.5 ± 8.9 µg/m3). The NO3- and SO42- concentrations increased as the air quality deteriorated. However, the proportion of NO3- and SO42- in PM2.5 slightly increased when the air quality deteriorated from moderate pollution (MP) to severe pollution (SP) levels. The average molar ratios of NH4+ to [NO3-+2 × (SO42-)] were 1.7, 0.9, 1.2, 1.2 and 1.5 for the heating periods of 2014/2015, 2015/2016, 2016/2017, 2017/2018 and 2018/2019, respectively, most of which were higher than 1.0, thus revealing an overall excess of NH4+ during the heating periods. However, the molar equivalent ratios of [NH4+] to [NO3-+2 × (SO42-)] were less than 1 under increasing PM2.5 pollution. The molar equivalent ratios of [NO3-]/[SO42-] were positively correlated with those of [NH4+]/[SO42-]. When the molar equivalent ratios of [NH4+]/[SO42-] were more than 1.5, those of [NO3-]/[SO42-] increased from close to 1 to higher values, indicating that the dominance of NO3- formation played an important role. The results of nonparametric wind regression exhibited distinct hot spots of NO3-, SO42- and NH4+ (higher concentrations) in the wind sectors between NE and SE at wind speeds of approximately 6-21 km/h. The southern areas in the North China Plain and parts of the western areas of China contributed more NO3-, SO42- and NH4+ than other areas to the study site. The abovementioned areas were also characterized by a higher contribution of NO3- than of SO42- to the study site and by NH4+-rich conditions. In summary, more efforts should be made to reduce NOx in the Beijing-Tianjin-Hebei region. This study provides observational evidence of the increasingly important role of nitrate as well as scientific support for formulating effective control strategies for regional haze in China.


Assuntos
Poluentes Atmosféricos/análise , Compostos de Amônio/análise , Nitratos/análise , Sulfatos/análise , Poluentes Atmosféricos/química , Poluição do Ar/análise , China , Monitoramento Ambiental , Material Particulado/análise , Estações do Ano , Transportes , Emissões de Veículos/análise , Água/química , Vento
9.
Thromb Res ; 198: 115-121, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33316640

RESUMO

INTRODUCTION: Long-term dual antiplatelet therapy (DAPT) has substantially reduced the risk of post-percutaneous coronary intervention (PCI) myocardial infarction and stent thrombosis at the expense of major bleeding. We hypothesized that a short-term DAPT followed by extended P2Y12 inhibitor monotherapy might be appropriate for patients with both high ischemic and bleeding risks. MATERIALS AND METHODS: We searched the databases: Pubmed, EMBASE, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov to identify randomized trials assessing the antiplatelet strategies after PCI. The primary safety endpoint was Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding. The efficacy outcome was a composite of all-cause mortality/cardiovascular disease (CVD) death, myocardial infarction, or stroke. A random-effect model was used to calculate the pooled hazard ratios (HRs) with 95% confidence intervals (CIs). RESULTS: We identified 5 randomized trials comparing P2Y12 inhibitor monotherapy with standard DAPT (12 months) (16,057 versus 16,088). P2Y12 inhibitor monotherapy following short-term DAPT (1 to 3 months) significantly reduced the risk of BARC type 3 or 5 bleeding compared to standard DAPT (pooled HR: 0.63, 95%CI: 0.46-0.86). The difference between P2Y12 inhibitor monotherapy and standard DAPT in reducing the composite CVD outcomes was not statistically significant (HR: 0.88, 95%CI: 0.77-1.01). CONCLUSIONS: P2Y12 inhibitor monotherapy might be an effective strategy for lowering severe bleeding complications and simultaneously preserving the ischemic benefit in patients receiving PCI.

10.
Environ Int ; 146: 106197, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-33271442

RESUMO

Biological particles in the Earth's atmosphere are a distinctive category of ice nucleating particles (INPs) due to their capability of facilitating ice crystal formation in clouds at relatively warm temperatures. Field observations and model simulations have shown that biological INPs affect cloud and precipitation formation and regulate regional or even global climate, although there are considerable uncertainties in modeling and large gaps between observed and model simulated contribution of biological particles to atmospheric INPs. This paper overviews the latest researches about biological INPs in the atmosphere. Firstly, we describe the primary ice nucleation mechanisms, and measurements and model simulations of atmospheric biological INPs. Secondly, we summarize the ice nucleating properties of biological INPs from diverse sources such as soils or dust, vegetation (e.g., leaves and pollen grains), sea spray, and fresh waters, and controlling factors of biological INPs in the atmosphere. Then we review the abundance and distribution of atmospheric biological INPs in diverse ecosystems. Finally, we discuss the open questions in further studies on atmospheric biological INPs, including the requirements for developing novel detection techniques and simulation models, as well as the comprehensive investigation of characteristics and influencing factors of atmospheric biological INPs.

11.
Opt Express ; 28(25): 37566-37576, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-33379589

RESUMO

The response of the optical microfiber sensor has a big difference due to the slight change in fiber structure, which greatly reduces the reliability of microfiber sensors and limits its practical applications. To avoid the nonlinear influences of microfiber deformation and individual differences on sensing performance, a backpropagation neural network (BPNN) is proposed for concentration prediction based on biconical microfiber (BMF) sensors. Microfiber diameter, cone angle, and relative intensity are the key input parameters for detecting the concentration of chlorophyll-a (from ∼0.03 mg/g to ∼0.10 mg/g). Hundreds of relative intensity-concentration data pairs acquired from 32 BMF sensors are used for the network training. The prediction ability of the model is evaluated by the root-mean-square error (RMSE) and the fitness value (F). The prediction performance of BPNN is compared with the traditional linear-fitting line method. After training, BPNN could adapt to the BMF sensors with different structural parameters and predict the nonlinear response caused by the small structural changes of microfiber. The concentration prediction given by BPNN is much closer to the actual measured value than the one obtained by the linear fitting curve (RMSE 1.84×10-3 mg/g vs. 4.6×10-3 mg/g). The numbers of training data and hidden layers of the BPNN are discussed respectively. The prediction results indicate that the one-hidden-layer network trained by more training data provides the best performance (RMSE and fitness values are 1.63×10-3 mg/g and 97.91%, respectively) in our experiments. With the help of BPNN, the performance of the BMF sensor is acceptable to the geometric deformation and fabrication error of microfiber, which provides an opportunity for the practical application of sensors based on micro/nanofibers.

12.
Artigo em Inglês | MEDLINE | ID: mdl-33223407

RESUMO

BACKGROUND AND AIMS: Efficient analysis strategies for complex network with cardiovascular disease (CVD) risk stratification remain lacking. We sought to identify an optimized model to study CVD prognosis using survival conditional inference tree (SCTREE), a machine-learning method. METHODS AND RESULTS: We identified 5379 new onset CVD from 2006 (baseline) to May, 2017 in the Kailuan I study including 101,510 participants (the training dataset). The second cohort composing 1,287 CVD survivors was used to validate the algorithm (the Kailuan II study, n = 57,511). All variables (e.g., age, sex, family history of CVD, metabolic risk factors, renal function indexes, heart rate, atrial fibrillation, and high sensitivity C-reactive protein) were measured at baseline and biennially during the follow-up period. Up to December 2017, we documented 1,104 deaths after CVD in the Kailuan I study and 170 deaths in the Kailuan II study. Older age, hyperglycemia and proteinuria were identified by the SCTREE as main predictors of post-CVD mortality. CVD survivors in the high risk group (presence of 2-3 of these top risk factors), had higher mortality risk in the training dataset (hazard ratio (HR): 5.41; 95% confidence Interval (CI): 4.49-6.52) and in the validation dataset (HR: 6.04; 95%CI: 3.59-10.2), than those in the lowest risk group (presence of 0-1 of these factors). CONCLUSION: Older age, hyperglycemia and proteinuria were the main predictors of post-CVD mortality. TRIAL REGISTRATION: ChiCTR-TNRC-11001489.

13.
Sci Total Environ ; : 143081, 2020 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-33190904

RESUMO

The variations in physicochemical properties of airborne particles collected during a typical transition from haze to dust were investigated using single particle analysis with transmission and scanning electron microscopes combined with online measurement of chemical compositions of airborne particles in Beijing in February 2013. The transition was divided into three phases based on the weather condition. During haze pollution (Phase 1), gaseous and particle pollutants enhanced gradually. Results from single particle analysis showed that more coatings and more anthropogenic elements (e.g., S) appeared on the surface of fine and coarse particles, which was probably caused by efficient aqueous-phase reactions under high humidity (70%) condition. Phase 2 was dust intrusion episode. PM10 reached over 1000 µg m-3. Larger fractions of mineral particles and bare-like soot particles were observed in fine particles, while the fraction of secondary particles with coatings decreased. The proportion of black carbon in submicron particles also increased. Photochemical oxidation in gas phase likely dominated in secondary formation under high O3 concentration. After the dust episode (Phase 3), secondary formation enhanced obviously. Soot aged quickly and had a larger mode of 0.45 µm than the other phases. The size modes of airborne fine particles during Phases 1 and 3 were 0.35 µm, which were a bit larger than that during Phase 2 (0.24 µm). These results indicate that dust plumes accompanied with strong wind brought mineral particles in both fine and coarse modes and freshly emitted particles with smaller sizes, and swept away pre-presence air pollutants. This study could provide detailed information on the physicochemical properties of airborne particles during typical severe pollution processes in a short time. Such short-term change should be taken into account in order to more accurately assess the environmental, climatic and health-related effects of airborne particles.

14.
Vet Microbiol ; : 108921, 2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-33191001

RESUMO

Coxsackievirus A16 (CA16) is one of predominant Enterovirus that possesses high pathogenicity. Lipid rafts, as cholesterol - and sphingolipid - enriched membrane nanodomains, are involved into many aspects of the virus life cycle. Our previous study found that lipid rafts integrity was essential for CA16 replication, but how lipid rafts regulate CA16 replication through activating downstream signaling remains largely unknown. Thus, in this study, we revealed that lipid rafts were required for activation of PI3K/Akt signaling at early stage of CA16 infection. Treatment with wortmannin significantly reduced the expression of virus protein, indicating PI3K/Akt signaling was beneficial for early stage of virus infection. In addition, lipid rafts integrity was also indispensable for PI3K/Akt activation during the late stage of CA16 infection, which played critical functions in mediating sterol regulatory element-binding proteins 1 (SREBP1) maturation. Whereas, over-expression of SREBP1 exhibited inhibition on virus replication, suggesting that PI3K/Akt signaling and SREBP1 might positively and negatively influence virus replication in two different stages of infection, respectively. Taken together, our study demonstrates an important role of the lipid raft-associated PI3K/Akt/SREBP1 signaling in modulating CA16 replication, which will deepen our understanding mechanism of CA16 infection.

15.
PLoS One ; 15(11): e0241980, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33171482

RESUMO

While many languages are in danger of extinction worldwide, multilingualism is being adopted for communication among different language groups, and is playing a unique role in preserving language and cultural diversities. How multilingualism is developed and maintained therefore becomes an important interdisciplinary research subject for understanding complex social changes of modern-day societies. In this paper, a mixed population of multilingual speakers and bilingual speakers in particular is considered, with multilingual defined broadly as zero, limited, or full uses of multiple languages or dialects, and an evolutionary dynamic model for its development and evolution is proposed. The model consists of two different parts, formulated as two different evolutionary games, respectively. The first part accounts for the selection of languages based on the competition for population and social or economic preferences. The second part relates to circumstances when the selection of languages is altered, for better or worse, by forces other than competition such as public policies, education, or family influences. By combining competition with intervention, the paper shows how multilingualism may evolve under these two different sources of influences. It shows in particular that by choosing appropriate interventional strategies, the stable co-existence of languages, especially in multilingual forms, is possible, and extinction can be prevented. This is in contrast with major predictions from previous studies that the co-existence of languages is unstable in general, and one language will eventually dominate while all others will become extinct.

16.
Front Genet ; 11: 768, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33193560

RESUMO

It is critical for patients who cannot undergo eradicable surgery to predict the risk of lung cancer recurrence and metastasis; therefore, the physicians can design the appropriate adjuvant therapy plan. However, traditional circulating tumor cell (CTC) detection or next-generation sequencing (NGS)-based methods are usually expensive and time-inefficient, which urge the need for more efficient computational models. In this study, we have established a convolutional neural network (CNN) framework called DeepLRHE to predict the recurrence risk of lung cancer by analyzing histopathological images of patients. The steps for using DeepLRHE include automatic tumor region identification, image normalization, biomarker identification, and sample classification. In practice, we used 110 lung cancer samples downloaded from The Cancer Genome Atlas (TCGA) database to train and validate our CNN model and 101 samples as independent test dataset. The area under the receiver operating characteristic (ROC) curve (AUC) for test dataset was 0.79, suggesting a relatively good prediction performance. Our study demonstrates that the features extracted from histopathological images could be well used to predict lung cancer recurrence after surgical resection and help classify patients who should receive additional adjuvant therapy.

17.
Faraday Discuss ; 2020 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-33244555

RESUMO

Surface ozone is a major pollutant threatening public health, agricultural production and natural ecosystems. While measures to improve air quality in megacities such as Delhi are typically aimed at reducing levels of particulate matter (PM), ozone could become a greater threat if these measures focus on PM alone, as some air pollution mitigation steps can actually lead to an increase in surface ozone. A better understanding of the factors controlling ozone production in Delhi and the impact that PM mitigation measures have on ozone is therefore critical for improving air quality. Here, we combine in situ observations and model analysis to investigate the impact of PM reduction on the non-linear relationship between volatile organic compounds (VOC), nitrogen oxides (NOx) and ozone. In situ measurements of NOx, VOC, and ozone were conducted in Delhi during the APHH-India programme in summer (June) and winter (November) 2018. We observed hourly averaged ozone concentrations in the city of up to 100 ppbv in both seasons. We performed sensitivity simulations with a chemical box model to explore the impacts of PM on the non-linear VOC-NOx-ozone relationship in each season through its effect on aerosol optical depth (AOD). We find that ozone production is limited by VOC in both seasons, and is particularly sensitive to solar radiation in winter. Reducing NOx alone increases ozone, such that a 50% reduction in NOx emissions leads to 10-50% increase in surface ozone. In contrast, reducing VOC emissions can reduce ozone efficiently, such that a 50% reduction in VOC emissions leads to ∼60% reduction in ozone. Reducing PM alone also increases ozone, especially in winter, by reducing its dimming effects on photolysis, such that a 50% reduction in AOD can increase ozone by 25% and it also enhances VOC-limitation. Our results highlight the importance of reducing VOC emissions alongside PM to limit ozone pollution, as well as benefitting control of PM pollution through reducing secondary organic aerosol. This will greatly benefit the health of citizens and the local ecosystem in Delhi, and could have broader application for other megacities characterized by severe PM pollution and VOC-limited ozone production.

18.
Brain Res Bull ; 2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33246036

RESUMO

BACKGROUND AND AIM: Ischemic stroke is one of the main causes of death worldwide and permanent global disability. On the basis of existing literature data, the study was carried out in an effort to explore how miR-140-5p affects ischemic stroke and whether the mechanism relates to toll-like receptor-4 (TLR4) and nuclear factor-kappa B (NF-κB). METHODS: Firstly, middle cerebral artery occlusion (MCAO) was performed to establish mouse models of ischemic stroke in vivo, while primary neurons were exposed to oxygen-glucose deprivation (OGD) to set up an ischemic stroke model in vitro. RT-qPCR was then applied to detect the miR-140-5p expression patterns, whereas Western blot was adopted to detect the expression patterns of TLR4, NF-κB, and apoptosis-related factors. In addition, based gain-function of experiments using miR-140-5p mimic and TLR4 over-expression plasmid, neurological function score, TTC staining, TUNEL staining, as well as flow cytometry were carried out to evaluate the effects of miR-140-5p and TLR4 on MCAO mice and OGD neurons. Moreover, dual-luciferase reporter assay was applied to validate the targeting relationship between miR-140-5p and TLR4. RESULTS: Initial findings revealed that miR-140-5p was poorly-expressed, while TLR4 was highly-expressed in ischemic stroke. It was verified that miR-140-5p targeted TLR4 and downregulated its expression. MiR-140-5p over-expression was observed to inhibit the apoptosis of neurons under OGD exposure and restrain the progression of ischemic stroke, while TLR4 over-expression promoted the apoptosis and disease progression. Besides, miR-140-5p over-expression led to a decrease in NF-κB protein levels, which were increased by TLR4 over-expression. CONCLUSION: In conclusion, our data indicates that miR-140-5p over-expression may be instrumental for the therapeutic targeting of ischemic stroke by alleviating neuron injury with the involvement of the TLR4/NF-κB axis.

19.
Faraday Discuss ; 2020 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-33241817

RESUMO

The hygroscopicity and ability of aerosol particles to act as cloud condensation nuclei (CCN) is important in determining their lifetime and role in aerosol-cloud interactions, thereby influencing cloud formation and climate. Previous studies have used the aerosol hygroscopic properties measured at the ground to evaluate the influence on cloud formation in the atmosphere, which may introduce uncertainty associated with aerosol hygroscopicity variability with altitude. In this study, the CCN behaviour and hygroscopic properties of daily filter collections of PM2.5 from three different heights (8, 120, 260 m) on a tower in Beijing were determined in the laboratory using water, water/methanol and methanol as the atomization solvents. Whilst there was substantial temporal variability in particle concentration and composition, there was little obvious difference in aerosol CCN and hygroscopic behaviour at different heights, although the planetary boundary layer height (PBLH) reduced to below the tower height during the nighttime, suggesting that use of surface hygroscopicity measurements is sufficient for the estimation of aerosol particle activation in clouds. Additionally, the critical coating thickness (in terms of mass ratio of coating/refractory BC, MRc) defining the BC transition between being hydrophobic to hydrophilic, was determined by combining hygroscopic tandem differential mobility analyser (H-TDMA), centrifugal particle mass analyzer (CPMA) and single particle soot photometer (SP2) measurements. The MRc of 250 nm BC-containing particles increased from a background value of between 0.8 and 1.6 to around 4.6 at the onset of the growth event of nanoparticles, decreasing monotonically back to the background level as the event progressed. This indicates that large particles do not act as an effective pre-existing condensation sink of the hygroscopic vapours during the nanoparticle growth events, leading to the 250 nm BC particles requiring more coating materials to transition between being hydrophobic and hydrophilic. These findings show that large particles may be less important in suppressing the new particle formation and subsequent growth in the atmosphere.

20.
J Food Sci Technol ; 57(11): 4247-4256, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33071346

RESUMO

The present study was conducted to evaluate the anti-hyperlipidemia ability of the dietary fiber extracted from okara in mice fed a high cholesterol diet. The dietary fiber was extracted from okara by combining fermentation with dynamic high-pressure microfluidization. An animal model was established to test the hypothesis that soluble dietary fiber, insoluble dietary fiber and total dietary fiber inhibit the fatty liver could be related to the total lipids and cholesterol including total cholesterol, triglyceride, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol in the serum. Compared with mice fed with simvastatin, mice fed dietary fiber can significantly reduce their serum total cholesterol, low-density lipoprotein cholesterol, triglyceride, and atherogenic index whereas no significant effect on high-density lipoprotein cholesterol was observed. Dietary fiber lowered a high level of liver total cholesterol and triglyceride. The dietary fiber extracted from okara might play an important role in the prevention of hyperlipidemia in high cholesterol mice and could be used as a natural supplement to a high cholesterol diet of functional food, due to the suppression of liver lipid synthesis.

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