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BACKGROUND: Ultrasensitive detection is crucial for the early warning and intervention of risk factors, ultimately benefiting the environment and human health. Low levels of ochratoxin A (OTA) present a hidden yet significant threat, and rapid detection via high-performing biosensors is therefore essential. RESULTS: A cascade isothermal amplification aptasensor (CIA-aptasensor) was designed for OTA detection. On the surface of a magnetic bead probe, the OTA level was converted into positively correlated trigger cDNA through its competitive binding with OTA-Apt. The released trigger cDNA activated catalytic hairpin assembly followed by coupling with a hybridization chain reaction to achieve CIA. After adding graphene oxide and SYBR Green I, the background interference was eliminated to specifically obtain OTA-related fluorescence. The ultrasensitive limit of detection was 0.22 pg mL-1, an improvement of 1368-fold over conventional enzyme-linked aptamer sorbent assay by the same OTA-Apt, demonstrating satisfactory reliability and practicability. Thus, the CIA-aptasensor provides an enzyme- and label-free simplified homogeneous system with minimal background interference using isothermal conditions. SIGNIFICANCE: This study provides a polymerase chain reaction-like approach for enhancing the sensitivity and performance of a biosensor, which could be extended for the application of CIA and label-free signaling strategy to other risk factors.
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Aptámeros de Nucleótidos , Técnicas Biosensibles , Límite de Detección , Técnicas de Amplificación de Ácido Nucleico , Ocratoxinas , Ocratoxinas/análisis , Aptámeros de Nucleótidos/química , Técnicas Biosensibles/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Grafito/químicaRESUMEN
Traditional loss functions such as cross-entropy loss often quantify the penalty for each mis-classified training sample without adequately considering its distance from the ground truth class distribution in the feature space. Intuitively, the larger this distance is, the higher the penalty should be. With this observation, we propose a penalty called distance-weighted Sinkhorn (DWS) loss. For each mis-classified training sample (with predicted label A and true label B), its contribution to the DWS loss positively correlates to the distance the training sample needs to travel to reach the ground truth distribution of all the A samples. We apply the DWS framework with a neural network to classify different stages of Alzheimer's disease. Our empirical results demonstrate that the DWS framework outperforms the traditional neural network loss functions and is comparable or better to traditional machine learning methods, highlighting its potential in biomedical informatics and data science.
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BACKGROUND: HCC is a leading cause of cancer-related death. The role of reactive oxygen species (ROS) in HCC remains elusive. Since a primary ROS source is the mitochondrial electron transport chain complex Ι and the NADH:ubiquinone Oxidoreductase Subunit B3 (NDUFB3), a complex I subunit, is critical for complex I assembly and regulates the associated ROS production, we hypothesize that some HCCs progress by hijacking NDUFB3 to maintain ROS homeostasis. METHODS: NDUFB3 in human HCC lines was either knocked down or overexpressed. The cells were then analyzed in vitro for proliferation, migration, invasiveness, colony formation, complex I activity, ROS production, oxygen consumption, apoptosis, and cell cycle. In addition, the in vivo growth of the cells was evaluated in nude mice. Moreover, the role of ROS in the NDUFB3-mediated changes in the HCC lines was determined using cellular and mitochondrion-targeted ROS scavengers. RESULTS: HCC tissues showed reduced NDUFB3 protein expression compared to adjacent healthy tissues. In addition, NDUFB3 knockdown promoted, while its overexpression suppressed, HCC cells' growth, migration, and invasiveness. Moreover, NDUFB3 knockdown significantly decreased, whereas its overexpression increased complex I activity. Further studies revealed that NDUFB3 overexpression elevated mitochondrial ROS production, causing cell apoptosis, as manifested by the enhanced expressions of proapoptotic molecules and the suppressed expression of the antiapoptotic molecule B cell lymphoma 2. Finally, our data demonstrated that the apoptosis was due to the activation of the c-Jun N-terminal kinase (JNK) signaling pathway and cell cycle arrest at G0/G1 phase. CONCLUSIONS: Because ROS plays essential roles in many biological processes, such as aging and cancers, our findings suggest that NDFUB3 can be targeted for treating HCC and other human diseases.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Animales , Ratones , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Ratones Desnudos , NAD , Especies Reactivas de Oxígeno , Ubiquinona , Homeostasis , OxidorreductasasRESUMEN
Single-cell technologies have emerged as a transformative technology enabling high-dimensional characterization of cell populations at an unprecedented scale. The data's innate complexity and voluminous nature pose significant computational and analytical challenges, especially in comparative studies delineating cellular architectures across various biological conditions (i.e., generation of sample level distance matrices). Optimal Transport (OT) is a mathematical tool that captures the intrinsic structure of data geometrically and has been applied to many bioinformatics tasks. In this paper, we propose QOT (Quantized Optimal Transport), a new method enables efficient computation of sample level distance matrix from large-scale single-cell omics data through a quantization step. We apply our algorithm to real-world single-cell genomics and pathomics datasets, aiming to extrapolate cell-level insights to inform sample level categorizations. Our empirical study shows that QOT outperforms OT-based algorithms in terms of accuracy and robustness when obtaining a distance matrix at the sample level from high throughput single-cell measures. Moreover, the sample level distance matrix could be used in downstream analysis (i.e. uncover the trajectory of disease progression), highlighting its usage in biomedical informatics and data science.
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Objective: To explore the effectiveness of the combined anteversion angle technique in total hip arthroplasty (THA) for treating ankylosing spondylitis (AS) affecting the hip joint. Methods: A retrospective analysis was conducted on the clinical data of 73 patients with AS affecting the hip joint who underwent THA between August 2018 and August 2021. According to whether the combined anteversion angle technique was used in THA, the patients were divided into study group (37 cases, combined anteversion angle technique was used in THA) and control group (36 cases, traditional THA). There was no significant difference in baseline data such as gender, age, body mass index, disease duration, preoperative Harris score, range of motion (ROM), acetabular anteversion angle, acetabular abduction angle, femoral anteversion angle, and combined anteversion angle between the two groups ( P>0.05). The operation time, hospital stay, and complications of the two groups were recorded and compared. The Harris score and hip ROM were compared between the two groups before operation, at 1, 3, 6, 12 months after operation, and at last follow-up. The acetabular component anteversion angle, femoral component anteversion angle, acetabular component abduction angle, and component combined anteversion angle were measured postoperatively. Results: The operation time in the study group was significantly shorter than that in the control group ( P<0.05), and there was no significant difference in hospital stay between the two groups ( P>0.05). There was no intraoperative complication such as acetabular and proximal femoral fractures, neurovascular injuries in both groups, and the incisions healed by first intention. All patients were followed up 2-3 years, with an average of 2.4 years; there was no significant difference in the follow-up time between the two groups ( P>0.05). During the follow-up period, there was no complication such as hip dislocation, wound infection, delayed wound healing, deep venous thrombosis, and hip dislocation in both groups. The hip Harris score and ROM of the two groups gradually increased with time after operation, and the differences were significant when compared with those before operation ( P<0.05); the above two indicators of the study group were significantly better than those of the control group at each time point after operation ( P<0.05). Extensive bone ingrowth on the surface of the components could be observed in the anteroposterior X-ray films of the hip joint of the two groups at 12 months after operation, and the acetabular components was stable without femoral stem subsidence, osteolysis around the components, and heterotopic ossification. At last follow-up, the acetabular component anteversion angle, femoral component anteversion angle, and component combined anteversion angle in the study group were significantly superior to those in the control group ( P<0.05), except that there was no significant difference in the acetabular component abduction angle between the two groups ( P>0.05). Conclusion: For patients with AS affecting the hip joint, the use of the combined anteversion angle technique during THA effectively promotes the recovery of hip joint function and enhances the postoperative quality of life of patients when compared to traditional THA.
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Artroplastia de Reemplazo de Cadera , Luxación de la Cadera , Prótesis de Cadera , Espondilitis Anquilosante , Humanos , Artroplastia de Reemplazo de Cadera/métodos , Luxación de la Cadera/cirugía , Espondilitis Anquilosante/cirugía , Estudios Retrospectivos , Calidad de Vida , Resultado del Tratamiento , Articulación de la Cadera/diagnóstico por imagen , Articulación de la Cadera/cirugíaRESUMEN
Glutamate dehydrogenase 1 (GLUD1) is an important enzyme in glutamine metabolism. Previously, we found GLUD1 was down-regulated in tumor tissues of hepatocellular carcinoma (HCC) patients by proteomics study. To explore its role in the progression of HCC, the expressional level of GLUD1 was firstly examined and presented as that both the protein and mRNA levels were down-regulated in tumor tissues compared to the normal liver tissues. GLUD1 overexpression significantly inhibited HCC cells proliferation, migration, invasion and tumor growth both in vitro and in vivo, while GLUD1 knocking-down promoted HCC progression. Metabolomics study of GLUD1 overexpressing and control HCC cells showed that 129 differentially expressed metabolites were identified, which mainly included amino acids, bases, and phospholipids. Moreover, metabolites in mitochondrial oxidative phosphorylation system (OXPHOS) were differentially expressed in GLUD1 overexpressing cells. Mechanistic studies showed that GLUD1 overexpression enhanced mitochondrial respiration activity and reactive oxygen species (ROS) production. Excessive ROS lead to mitochondrial apoptosis that was characterized by increased expression levels of p53, Cytochrome C, Bax, Caspase 3 and decreased expression level of Bcl-2. Furthermore, we found that the p38/JNK MAPK pathway was activated in GLUD1 overexpressing cells. N-acetylcysteine (NAC) treatment eliminated cellular ROS and blocked p38/JNK MAPK pathway activation, as well as cell apoptosis induced by GLUD1 overexpression. Taken together, our findings suggest that GLUD1 inhibits HCC progression through regulating cellular metabolism and oxidative stress state, and provide that ROS generation and p38/JNK MAPK pathway activation as promising methods for HCC treatment.
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Anthropogenic emissions have emerged as an important source of urban atmospheric PM2.5, exacerbating air pollution and the associated health implications. This study analyses PM2.5, originating from major anthropogenic sources (industries, motor vehicles, and solid-fuel combustion for domestic applications) in the Guanzhong Plain in China, along with the parent- (p-), alkylated- (a-), and oxygenated- (o-) polycyclic aromatic hydrocarbons (PAHs) and reactive oxygen species (ROS) levels in PM2.5. Industrial emissions are mainly characterised by high abundances of benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), and benz[a]fluoranthene (BaF). The 4-ring p-PAHs, such as fluoranthene (FLA), pyrene (PYR), benzo[a]anthracene (BaA), and chrysene (CHR) proportions and the diagnostic ratios of indeno[1,2,3-cd]pyrene (IcdP)/[IcdP + benzo[ghi]perylene (BghiP)] and 1-acenaphthenone (1ACO)/[1ACO + 9-fluorenone (9FO)] in motor vehicle emission PM2.5 were higher than the other sources. Household solid fuel combustion features high proportions of methylnaphthalene (M-NAP), i.e., 2 M-NAP and 1 M-NAP and 3-ring p-PAHs. Acenaphthylene (ACY), acenaphthene (ACE), anthracene (ANT), 1,4-chrysenequinone (1,4CHRQ), and reactive oxygen species (ROS) were positively correlated among the three anthropogenic sources. Moreover, the correlations between other PAHs and ROS varied significantly among the three sources. As mixed and compound organic pollutants, 2- and 3-ring p-PAHs were more positively correlated with the ROS activity of household solid fuel combustion sources compared with industrial and motor vehicle sources. Based on the relative contribution of these three sources to PAHs in PM2.5, we estimated the cancer risks of males and females in the Guanzhong area to be 2.95 × 10-6 and 2.87 × 10-6, respectively, exceeding the safety threshold of 1 × 10-6. This study provides a basic dataset for conducting a refined source apportionment of PM2.5 and a scientific basis for further understanding the relationship between PM2.5, PAHs, and ROS in northern China.
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Solid fuel combustion for domestic heating in northern China in the wintertime is of great environmental and health concern. This study assesses personal exposure to particulate matter with different aerodynamic diameters and multiple gaseous pollutants from 123 rural residents in Yuncheng, the Fenwei Plain. The subjects are divided into groups based on the unique energy source applied, including biomass, coal, and electricity/no heating activities. The health effects of the exposures are expressed with four urinary biomarkers. The personal exposure levels to three different aerodynamic particle sizes (i.e., PM10, PM2.5, and PM1) of the electricity/no heating group are 5.1 % -12 % lower than those of the coal group. In addition, the exposure levels are 25 %-40 % lower for carbon monoxide (CO) and 10.8 %-20.3 % lower for ozone (O3) in the electricity/no heating group than the other two fuel groups. C-reactive protein (CRP) in the urine of the participants in biomass and coal groups is significantly higher than that in the electricity/no heating group, consistent with the observations on other biomarkers. Increases in 8-hydroxy-2 deoxyguanosine (8-OHdG), interleukin-8 (IL-8), and vascular endothelial growth factor (VEGF) are observed for the exposures to higher concentrations of air pollutants. For instance, PMs and nitrogen dioxide (NO2) show significant impacts on positive correlations with 8-OHdG and IL-8, while O3 positively correlates with CRP. PM1 exhibits higher effects on the biomarkers than the gaseous pollutants, especially on VEGF and IL-8. The study indicates that excessive use of traditional domestic solid fuels could pose severe health effects on rural residents. The promotion of using clean energy is urgently needed in the rural areas of northern China.
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Contaminantes Atmosféricos , Contaminación del Aire Interior , Humanos , Interleucina-8 , Factor A de Crecimiento Endotelial Vascular , Monitoreo del Ambiente , Material Particulado/análisis , Contaminantes Atmosféricos/análisis , Culinaria , Carbón Mineral , China , Biomarcadores , Contaminación del Aire Interior/análisisRESUMEN
Industrial emission has been proved to be an important source of atmospheric PM2.5, which causes serious air pollution and health impacts. The air quality of the industrial zones, which are the intermediate stationary areas between the direct emissions and diffusion to the atmosphere, is always overlooked. In this study, the PM2.5 filter samples were collected in the six representative types of industrial zones in four cities of the Guanzhong Plain in 2020. The chemical characteristics of fine particulate matter (PM2.5) in the zones were investigated. The mass concentrations of 13 elements and 39 polycyclic aromatic hydrocarbons (PAHs) in PM2.5 were quantified. Cement and concrete (CC) and brick production (BP) exhibited a similar chemical composition profile characterized by high proportions of calcium (Ca), aluminum (Al), benzo[k]fluoranthene (BkF), 1-nitronaphthalene (1N-NAP), and 3-nitrofluoranthene (3N-FLA). Glassware and ceramics (GC) showed a distinguishable profile with a relatively low ratio of copper/cadmium (Cu/Cd) and lead (Pb)/Cd. The profile for metal forging (MF) was abundant in vanadium (V), Pb, indeno[1,2,3-cd]pyrene (IcdP) and also recognized by particular diagnostic ratios of nitrated-PAHs (n-PAHs). The highest proportions of several metals such as chromium (Cr), manganese (Mn), iron (Fe), nickel (Ni), zinc (Zn), Cd, and fluoranthene (FLA) were found in the thermoelectric industry (TI) due to a large amount of coal consumption in the manufacture processing. Chemical production (CP) was the only industrial type using natural gas as the main fuel in this study, which shows the distinguishing feature of relatively high proportions of low molecular weight parent-PAHs (p-PAHs) and 2-ring oxygenated-PAHs (o-PAHs). This study not only attains the detailed chemical fingerprints, but also the potential tracers and ratios, which are of great significance for refining source apportionment and relieving PM2.5 pollution contributed by the industrial sources.
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Contaminantes Atmosféricos , Hidrocarburos Policíclicos Aromáticos , Contaminantes Atmosféricos/análisis , China , Monitoreo del Ambiente , Plomo , Material Particulado/análisis , Hidrocarburos Policíclicos Aromáticos/análisisRESUMEN
A vehicular emission study was conducted in the longest inner-city tunnel in Xi'an, northwestern China in four time periods (I: 07:30-10:30, II: 11:00-14:00, III: 16:30-19:30, and IV: 20:00-23:00 LST). A sum of 40 PAHs, including parent (p-PAHs), alkylated (a-PAHs), and oxygenated (o-PAHs) in fine particulate matter (PM2.5) were quantified. The relationships between the PAHs and the formation of reactive oxygen species (ROS) were also studied. The average total quantified PAHs concentration was 236.3 ± 48.3 ng m-3. The p-PAHs were found to be the most dominated group, accounting for an average of 88.1% of the total quantified PAHs, followed by a-PAHs (6.1%) and o-PAHs (5.8%). On the base of the number of aromatic rings, the groups of ≤5 rings (92.5 ± 1.2%) had higher fractions than the high ones (≥6 rings, 7.5 ± 1.2%) for pPAHs. Diurnal variations of PAHs subgroups exhibited the highest levels in Period III, consistent with the largest traffic counts in evening rush hours. However, less reduction of few PAHs in the night period demonstrates that the emissions of compressed natural gas (CNG) and methanol-fueled vehicles cannot be ignored while their contribution increased. High ROS activity levels were observed in the traffic-dominated samples, implying the potential oxidative damages to humans. Additionally, diurnal variation of the ROS activity was consistent with the total quantified PAHs and toxic equivalency of benzo[a]pyrene. Good correlations (R > 0.6, p < 0.05) were seen between individual groups of PAHs (especially for 3-5 rings p-PAHs, 4 rings a-PAHs, and 2-3 rings o-PAHs) and ROS activity, supporting that the vehicular emitted PAHs possibly initiate oxidative stress. The multiple linear regression analysis further illustrated that chrysene contributed the highest (25.0%) to ROS activity. In addition to highlighting the potential hazards to the PAHs from the vehicular emission, their roles to mitigate the health effects by formations of ROS were firstly reported in northwestern China.
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Contaminantes Atmosféricos , Hidrocarburos Policíclicos Aromáticos , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/toxicidad , China , Monitoreo del Ambiente , Humanos , Material Particulado/análisis , Material Particulado/toxicidad , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/toxicidad , Especies Reactivas de Oxígeno/análisis , Emisiones de Vehículos/análisis , Emisiones de Vehículos/toxicidadRESUMEN
PURPOSE: Predicting the prognosis in laryngeal squamous cell carcinoma (LSCC) patients will improve clinical decision-making. Here, we aimed to identify a qualitative signature based on the within-sample relative expression orderings (REOs) of microRNA (miRNA) pairs to predict the overall survival (OS) of LSCC patients. METHODS: First, we constructed non-repeating miRNA pairs based on differentially expressed miRNAs (DEmiRNAs) between LSCC and normal tissues. Then, we applied a bootstrap-based feature selection method to identify a robust miRNA-pair signature. The bootstrap-based feature selection improved the stability of feature selection by an ensemble based on the data perturbation. Furthermore, a series of bioinformatics analyses were carried out to explore the potential mechanisms of the signature and potential drug targets for LSCC. RESULTS: Based on the REOs of miRNA pairs, we identified a qualitative signature that consisted of 12 miRNA pairs. The constructed signature has good performance in predicting the OS of LSCC patients. It is robust against batch effects and more suitable for individual clinical applications. Furthermore, we identified several hub genes that may be potential drug targets for LSCC. CONCLUSION: Overall, our findings provided a promising signature for predicting the OS of LSCC patients.
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Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias Laríngeas , MicroARNs , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Regulación Neoplásica de la Expresión Génica , Neoplasias de Cabeza y Cuello/genética , Humanos , Neoplasias Laríngeas/genética , Neoplasias Laríngeas/patología , MicroARNs/genética , MicroARNs/metabolismo , Pronóstico , Carcinoma de Células Escamosas de Cabeza y Cuello/genéticaRESUMEN
The clean heating renovation has been executed for improving particulate matter (PM) pollution in northern China since 2017. This study determined particle size distributions of nitrated phenols (NPs) in personal exposure samples and their associations with biomarkers in saliva and urine from homemakers in rural households of the Fenwei Plain, China. Remarkable reductions of 28.6-66.3% and 52.2-82.4% on PMs and total quantified NPs, respectively, were found with the substitutions of raw coal chunk and biomass by advanced clean coal. 4-Nitroguaiacol (4NG) showed the largest reductions of 81.2% among individual NP. In addition, the clean coal efficiently reduced interleukin-6 (IL-6) and 8-hydrox-2'-deoxyguanosine (8-OHdG) in the urine and saliva by 12-72%. Furthermore, significant positive correlations between urinary 8-OHdG with most of NPs in all particle sizes, urinary IL-6 with 4NG for particles with Dp > 2.5 µm and Dp = 0.25-1.0 µm and salivary IL-6 with 4-nitrocatechol and 4-methyl-5-nitrocatechol for particles with Dp > 2.5 µm, Dp = 0.5-1.0 µm, and Dp < 0.25 µm were observed but not for salivary 8-OHdG or PMs. The results provide scientific support for the clean energy reformation and demonstrate the strong particle size dependence between NPs and biomarkers.
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Contaminantes Atmosféricos , Contaminación del Aire Interior , Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/análisis , China , Carbón Mineral , Monitoreo del Ambiente , Calefacción , Nitratos , Tamaño de la Partícula , Material Particulado/análisis , FenolesRESUMEN
The knowledge of the anatomical shape of both gross and microscopic structures is the key to understanding the effects of disease processes on cellular structure. Geometric morphometric methods, such as Procrustes superimposition, and Spherical Harmonics (SPHARM), have been used to capture the biological shape variation and group differences in morphology. Previous SPHARM-MAT techniques use the CALD algorithm to parameterize the mesh surface. It starts from initial mapping and performs local and global smoothing methods alternately to control the area and length distortions simultaneously. However, this parameterization may not be sufficient in complex morphological cases. To bridge this gap, we propose SPHARM-OT, an enhanced SPHARM surface modeling method using optimal transport (OT) for spherical parameterization. First, the genus 0 3D objects are conformally mapped onto a sphere. Then the optimal transport theory via spherical power diagram is introduced to minimize the area distortion. This new algorithm can effectively reduce the area distortion and lead to a better reconstruction result. We demonstrate the effectiveness of the method by applying it to the human sphenoidal paranasal sinuses.
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Background and purpose: Diagnosis of dementia with Lewy bodies (DLB) is highly challenging, primarily due to a lack of valid and reliable diagnostic tools. To date, there is no report of qualitative signature for the diagnosis of DLB. We aimed to develop a blood-based qualitative signature for differentiating DLB patients from healthy controls. Methods: The GSE120584 dataset was downloaded from the public database Gene Expression Omnibus (GEO). We combined multiple methods to select features based on the within-sample relative expression orderings (REOs) of microRNA (miRNA) pairs. Specifically, we first quickly selected miRNA pairs related to DLB by identifying reversal stable miRNA pairs. Then, an optimal miRNA pair subset was extracted by random forest (RF) and support vector machine-recursive feature elimination (SVM-RFE) methods. Furthermore, we applied logistic regression (LR) and SVM to build several prediction models. The model performance was assessed using the receiver operating characteristic curve (ROC) analysis. Lastly, we conducted bioinformatics analyses to explore the molecular mechanisms of the discovered miRNAs. Results: A qualitative signature consisted of 17 miRNA pairs and two clinical factors was identified for discriminating DLB patients from healthy controls. The signature is robust against experimental batch effects and applicable at the individual levels. The accuracies of the-signature-based models on the test set are 82.61 and 79.35%, respectively, indicating that the signature has acceptable discrimination performance. Moreover, bioinformatics analyses revealed that predicted target genes were enriched in 11 Go terms and 2 KEGG pathways. Moreover, five potential hub genes were found for DLB, including SRF, MAPK1, YWHAE, RPS6KA3, and KDM7A. Conclusion: This study provided a blood-based qualitative signature with the potential to be used as an effective tool to improve the accuracy of DLB diagnosis.
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Traffic source-dominated volatile organic compound (VOC) samples were collected during four time-intervals in a day (â : 7:30-10:30, â ¡: 11:00-14:00, â ¢: 16:30-19:30, and â £: 20:00-23:00) in a tunnel in summer, 2019, in Xi'an, China. The total measured VOC (TVOC) in periods â and â ¢ (rush hours, 107.2 ± 8.2 parts per billion by volume [ppbv]) was 1.8 times that in periods â ¡ and â £ (non-rush hours, 58.6 ± 13.8 ppbv), consistent with the variation in vehicle numbers in the tunnel. The considerably elevated ethane and ethylbenzene levels could have been attributed to emissions from compressed natural gas vehicles and the rapid development of methanol-fueled taxis in Xi'an in 2019. The mixing ratios of benzene, toluene, ethylbenzene, and xylenes (BTEX) contributed 9.4%-12.7% to TVOCs, and the contributions were nearly 40% higher in periods â and â ¢ than in â ¡ and â £, indicating that BTEX levels were strongly affected by vehicle emissions. The indicators of motor vehicle emission, namely ethylene, propylene, toluene, m/p-xylenes, o-xylene, and propane, contributed to more than half of the ozone formation potential in this study. The noncarcinogenic risks of VOCs in this study were within the international safety standard, whereas the carcinogenic risks exceeded the standard by 2.3-4.6 times, suggesting that carcinogenic risks were more serious than noncarcinogenic risks. VOCs presented 2.2 and 1.4 times noncarcinogenic and carcinogenic risks during rush hours than during non-rush hours, respectively. Notably, the carcinogenic risk in period â £ was comparable with that in period â ¢; however, the vehicle numbers and VOC mixing ratios were the lowest at night, which may have attributed to the increasing number and proportion of methanol M100-fueled vehicles in the tunnel. Therefore, VOCs emitted by new energy vehicles should also be seriously considered while evaluating fossil fuel vehicle emissions.
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Contaminantes Atmosféricos , Compuestos Orgánicos Volátiles , Contaminantes Atmosféricos/análisis , China , Monitoreo del Ambiente , Emisiones de Vehículos/análisis , Compuestos Orgánicos Volátiles/análisisRESUMEN
BACKGROUND: The health effects of heavy solid fuel use in winter in rural China are of concern. The effects of air pollution resulting from domestic solid fuel combustion in rural households on rural homemakers' biomarkers were revealed in this study. METHODS: In total, 75 female homemakers from rural areas of Guanzhong Basin, the Fenwei Plain, People's Republic of China, were randomly selected and divided into three groups (biomass users, coal users, and nonusers of solid fuel user [control group]). The differences in biological indicators, including 8-hydrox-2'-deoxyguanosine (8-OHdG), interlukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) in urine samples as well as blood pressure (BP, including systolic BP [SBP] and diastolic BP [DBP]) and heart rate (HR) among the groups in winter and summer were investigated using statistical analysis. RESULTS: IL-6, 8-OHdG, HR, SBP, and DBP were significantly higher in winter than in summer (P < 0.05) owing to the poor air quality resulted from the excessive use of solid fuels in winter. Significant seasonal differences in 8-OHdG were observed for both coal and biomass users. After the influence of confounders was removed, only IL-6 levels in the urine of solid fuel users were significantly higher than that of the control group. CONCLUSIONS: IL-6 is a sensitive biomarker representing inflammatory responses to particulate matter emitted through household solid fuel combustion. Locally, excessive use of solid fuels in winter posed serious PM2.5 pollution in this area and adverse effects on inflammatory biomarkers in these rural homemakers and induced DNA damage related to oxidative stress.
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Contaminantes Atmosféricos , Contaminación del Aire Interior , Culinaria , Interleucina-6/orina , Material Particulado , 8-Hidroxi-2'-Desoxicoguanosina/orina , Adulto , Anciano , Biomarcadores/orina , Presión Sanguínea , China , Femenino , Frecuencia Cardíaca , Humanos , Persona de Mediana Edad , Distribución Aleatoria , Población Rural , Factor de Necrosis Tumoral alfa/orinaRESUMEN
Ultrafine-grained die-upset Nd-Fe-B magnets are of importance because they provide a wide researching space to redesign the textured structures. Here is presented a route to obtain a new die-upset magnet with substantially improved magnetic properties. After experiencing the optimized heat treatment, both the coercivity and remanent magnetization of the Dy-Cu press injected magnets increased substantially in comparison with those of the annealed reference magnets, which is distinct from the reported experimental results on heavy rare-earth diffusion. To study the mechanism, we analyzed the texture evolution in high-temperature annealed die-upset magnets, which had significant impact on the improvement of remanent magnetization. On basis of the results, we find that the new structures are strongly interlinked with the initial structures. With injecting Dy-Cu eutectic alloy, an optimized initial microstructure was achieved in the near-surface diffused regions, which made preparations for the subsequent texture improvement. Besides, the Dy gradient distribution of near-surface regions of the Dy-Cu press injected magnets was also investigated. By controlling the initial microstructure and subsequent diffusion process, a higher performance magnet is expected to be obtained.