Severe PM2.5 pollution was observed frequently in Beijing. We conducted highly time-resolved measurements of inorganic ions associated with PM2.5 at an urban site in Beijing from 10 February to 19 ...March, 2015. The average PM2.5 mass concentrations during the six haze episodes ranged from 113.0 μg/m3 to 182.6 μg/m3, which were more than 8 times higher than those observed in clean periods. The secondary inorganic species (NH4+, SO42− and NO3−) in PM2.5 sharply increased during the haze episodes, indicating more extensive formation of SO42− and NO3−. The sulfur oxidation ratios (SOR) and the nitrogen oxidation ratios (NOR) in haze episodes were higher than those in clean periods, which indicated that secondary transformation in haze episodes was more significant than those in clean periods. No correlations between SOR and the oxidants (O3 and HONO) and the temperature were found, whereas a high correlation between SOR and relative humidity (RH) was found in haze episodes, which implied that sulfate was mainly produced by the aqueous-phase oxidation of SO2 rather than the gas-phase conversion of SO2 to sulfate. The conversion of SO2 to SO42− was observed to be sensitive to changes in RH. Furthermore, the SOR sharply increased at RH > 60% with the highest value of 0.88 at RH around 80% during complicated pollution. NO2 played an important role in the rapid sulfate formation with high RH and NH3 neutralization conditions in haze episodes in Beijing. The impact of RH was less apparent for nitrate than for sulfate. Nitrate was found to be produced mainly by photochemical and heterogeneous reactions, while heterogeneous reactions had a greater influence on NOR at nighttime. The NO3−/SO42− ratio indicated that mobile sources contributed more to the formation of PM2.5 than stationary sources. The result suggested the need for control of vehicle emissions to reduce the high levels of NOx and nitrate and the severe PM2.5 pollution in Beijing.
•Secondary formation significantly strengthened the haze episode.•High RH was a favorable factor for the aqueous phase oxidation of SO2.•NO2 played an important role in the sulfate rapid formation.•Vehicle emission control was conducive to reduce fine particulate nitrate in Beijing.
With the rapid increase of multiple drug-resistant bacteria, silver nanoparticles (AgNPs) with broad-spectrum antibacterial activities have been widely applied in the treatment of bacterial ...infection. Meanwhile, AgNPs also have anticancer activities against different cell lines. The toxic effects of AgNPs depend on concentration, size, shape, coated materials and surrounding environments. In order to better understand the antibacterial and antitumor effects of AgNPs, various investigations have been carried out to uncover the molecular mechanism of action. This review summarizes the recent studies on the action mechanisms of AgNPs related to their antibacterial activities including collapsing cell walls, inducing reactive oxygen species, inhibiting aerobic respiration and damaging DNA and their antitumor effects including impairing mitochondria, blocking cell cycle, and activating apoptosis. In these investigations, the systematic approaches have not been extensively applied. Increasingly matured omics techniques including genomics, transcriptomic, translatomics and proteomics should be more widely explored to provide the comprehensive views of the cytotoxic effects of AgNPs to bacteria and tumor cells and thus globally illustrate the molecular mechanisms of the cytotoxicity, promoting the better medical application of AgNPs in the future.
Translational systems can respond promptly to sudden environmental changes to provide rapid adaptations to environmental stress. Unlike the well-studied translational responses to oxidative stress in ...eukaryotic systems, little is known regarding how prokaryotes respond rapidly to oxidative stress in terms of translation. In this study, we measured protein synthesis from the entire Escherichia coli proteome and found that protein synthesis was severely slowed down under oxidative stress. With unchanged translation initiation, this slowdown was caused by decreased translation elongation speed. We further confirmed by tRNA sequencing and qRT-PCR that this deceleration was caused by a global, enzymatic downregulation of almost all tRNA species shortly after exposure to oxidative agents. Elevation in tRNA levels accelerated translation and protected E. coli against oxidative stress caused by hydrogen peroxide and the antibiotic ciprofloxacin. Our results showed that the global regulation of tRNAs mediates the rapid adjustment of the E. coli translation system for prompt adaptation to oxidative stress.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Sepsis-associated encephalopathy (SAE) is prevalent in intensive care unit (ICU) environments but lacks established treatment protocols, necessitating prompt diagnostic methods for early ...intervention. Traditional symptom-based diagnostics are non-specific and confounded by sedatives, while emerging biomarkers like neuron-specific enolase (NSE) and S100 calcium-binding protein B (S100B) have limited specificity. Transcranial Doppler (TCD) indicators, although is particularly relevant for SAE, requires high operator expertise, limiting its clinical utility.
This pilot study aims to utilize cerebral circulation time (CCT) assessed via contrast-enhanced ultrasound (CEUS) as an innovative approach to investigate the accuracy of SAE prediction. Further, these CCT measurements are integrated into a nomogram to optimize the predictive performance.
This study employed a prospective, observational design, enrolling 67 ICU patients diagnosed with sepsis within the initial 24 h. Receiver operating characteristic (ROC) curve analyses were conducted to assess the predictive accuracy of potential markers including NSE, S100B, TCD parameters, and CCT for SAE. A nomogram was constructed via multivariate Logistic Regression to further explore the combined predictive potential of these variables. The model's predictive performance was evaluated through discrimination, calibration, and decision curve analysis (DCA).
SAE manifested at a median of 2 days post-admission in 32 of 67 patients (47.8%), with the remaining 35 sepsis patients constituting the non-SAE group. ROC curves revealed substantial predictive utility for CCT, pulsatility index (PI), and S100B, with CCT emerging as the most efficacious predictor, evidenced by an area under the curve (AUC) of 0.846. Multivariate Logistic Regression identified these markers as independent predictors for SAE, leading to the construction of a nomogram with excellent discrimination, substantiated by an AUC of 0.924 through bootstrap resampling. The model exhibited satisfactory concordance between observed and predicted probabilities, and DCA confirmed its clinical utility for the prompt identification of SAE.
This study highlighted the enhanced predictive value of CCT in SAE detection within ICU settings. A novel nomogram incorporating CCT, PI, and S100B demonstrated robust discrimination, calibration, and clinical utility, solidifying it as a valuable tool for early SAE intervention.
Ethanolysis is an effective method to depolymerize weak bonds in lignite under mild conditions, which can result in the production of high-value-added chemicals. However, improving ethanolysis yield ...and regulating its resulting product distribution is a big challenge. Hence, exploiting highly active catalysts is vital. In this work, Fe2(MoO4)3 catalysts with zero-dimensional nanoparticles, one-dimensional (1D) nanorods, two-dimensional (2D) nanosheets, and three-dimensional (3D) nanoflower structures were successfully prepared and applied in the ethanolysis of Naomaohu coal. The results showed that for all samples, the yield of ethanol-soluble portions (ESP) was significantly improved. The highest yield was obtained for the Fe2(MoO4)3 nanorods, with an increase from 28.84% to 47.68%, and could be attributed to the fact that the Fe2(MoO4)3 nanorods had a higher number of exposed active (100) facets. In addition, the amounts of oxygen-containing compounds, such as ethers, esters, and phenols, increased significantly. The mechanism of ethanolysis catalyzed by the Fe2(MoO4)3 nanorods was also studied using phenylbenzyl ether (BOB) as a model compound. BOB was completely converted at 260 °C after 2 h. It is suggested that Fe2(MoO4)3 nanorods can effectively break the C-O bonds of coal macromolecules, thus promoting the conversion of coal.
Parkinson's disease is the second most common neurodegenerative disease in the world. However, current diagnostic methods are still limited, and available treatments can only mitigate the symptoms of ...the disease, not reverse it at the root. The immune function has been identified as playing a role in PD, but the exact mechanism is unknown. This study aimed to search for potential immune-related hub genes in Parkinson's disease, find relevant immune infiltration patterns, and develop a categorical diagnostic model.
We downloaded the GSE8397 dataset from the GEO database, which contains gene expression microarray data for 15 healthy human SN samples and 24 PD patient SN samples. Screening for PD-related DEGs using WGCNA and differential expression analysis. These PD-related DEGs were analyzed for GO and KEGG enrichment. Subsequently, hub genes (dld, dlk1, iars and ttd19) were screened by LASSO and mSVM-RFE machine learning algorithms. We used the ssGSEA algorithm to calculate and evaluate the differences in nigrostriatal immune cell types in the GSE8397 dataset. The association between dld, dlk1, iars and ttc19 and 28 immune cells was investigated. Using the GSEA and GSVA algorithms, we analyzed the biological functions associated with immune-related hub genes. Establishment of a ceRNA regulatory network for immune-related hub genes. Finally, a logistic regression model was used to develop a PD classification diagnostic model, and the accuracy of the model was verified in three independent data sets. The three independent datasets are GES49036 (containing 8 healthy human nigrostriatal tissue samples and 15 PD patient nigrostriatal tissue samples), GSE20292 (containing 18 healthy human nigrostriatal tissue samples and 11 PD patient nigrostriatal tissue samples) and GSE7621 (containing 9 healthy human nigrostriatal tissue samples and 16 PD patient nigrostriatal tissue samples).
Ultimately, we screened for four immune-related Parkinson's disease hub genes. Among them, the AUC values of dlk1, dld and ttc19 in GSE8397 and three other independent external datasets were all greater than 0.7, indicating that these three genes have a certain level of accuracy. The iars gene had an AUC value greater than 0.7 in GES8397 and one independent external data while the AUC values in the other two independent external data sets ranged between 0.5 and 0.7. These results suggest that iars also has some research value. We successfully constructed a categorical diagnostic model based on these four immune-related Parkinson's disease hub genes, and the AUC values of the joint diagnostic model were greater than 0.9 in both GSE8397 and three independent external datasets. These results indicate that the categorical diagnostic model has a good ability to distinguish between healthy individuals and Parkinson's disease patients. In addition, ceRNA networks reveal complex regulatory relationships based on immune-related hub genes.
In this study, four immune-related PD hub genes (dld, dlk1, iars and ttd19) were obtained. A reliable diagnostic model for PD classification was developed. This study provides algorithmic-level support to explore the immune-related mechanisms of PD and the prediction of immune-related drug targets.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In today’s society, the environment is a frontier topic, and the topic of environmental sustainability has attracted attention. There are also many sustainable development ideas in the economic ...field. The main topic is circular economy, which is mainly to cultivate a harmonious coexistence environment for the development of man and nature by strengthening the construction of the ecological environment and ecological industries. Therefore, when solving environmental problems, we must adapt measures to local conditions and develop a circular economy to fundamentally solve the problems that have always existed between resources, environment and development. For regional economies, we must create new ideas on the road to industrialization and make full use of Resources provide a foundation for the realization of the overall construction goals of a well-off society in the near future, and contribute to the realization of grand goals. In this study, we will take the environmental problems in a certain area as an example, aiming at the environmental problems in the area and the goals of national policies for ecological environment construction, summarizing the content of existing research, and conducting a preliminary analysis of this content. A framework of thinking based on ecological environment quality evaluation is proposed. Technically, remote sensing and geographic information systems are used, and the survey results and research results summarized with sufficient reasons are used to conduct a single-factor analysis of the ecological environment in the area, and establish a relevant database of the ecological environment in the area. The focus of this article is to establish a complete set of evaluation system compared with the current situation and development of circular economy, and compared with foreign circular economy development models. The main contents include the evaluation of the reduction of resource input, the evaluation of the effect of resource recovery and reuse, the evaluation of the reduction of pollution emissions, the evaluation of the improvement of ecological environment quality, and the evaluation of the comprehensive development level of the socio-economic development of the area. On the basis of some evaluations, it is necessary to use the entropy method to make a comprehensive analysis and evaluation of regional economic development. The evaluation system of this article is relatively complete and comprehensive, integrating resources, environment and economic benefits.
•Adapt measures to local conditions and develop a circular economy.•Aiming at the environmental problems in the area and the goals of national policies for ecological environment construction.•Summarizing the content of existing research, and conducting a preliminary analysis of this content.•Use the entropy method to make a comprehensive analysis and evaluation of regional economic development.
Helicobacter pylori
infections are closely associated with peptic ulcers, gastric malignancy and iron deficiency anemia. Iron is essential for almost all living organisms and the investigation of ...iron uptake and trafficking system is thus important to understand the pathological roles of
H. pylori
. Up to now, the iron trafficking system of
H. pylori
is not yet fully clear and merits further efforts in this regards. The available information about iron uptake and regulation has been discussed in this concise review, such as FeoB in ferrous transportation, FrpB2 in hemoglobin uptake, HugZ in heme processing, virulence factors (VacA and CagA) in transferrin utilization, Pfr and NapA in iron storage and Fur in iron regulation. The identified iron trafficking system will help us to understand the pathological roles of
H. pylori
in the various gastric diseases and iron deficiency anemia and stimulates further development of effective anti-bacterial drugs.
Lysine crotonylation has attracted widespread attention in recent years. However, little is known about bacterial crotonylation, particularly crotonyltransferase and decrotonylase, and its effects on ...antibiotic resistance. Our study demonstrates the ubiquitous presence of crotonylation in E. coli, which promotes bacterial resistance to polymyxin. We identify the crotonyltransferase YjgM and its regulatory pathways in E. coli with a focus on crotonylation. Further studies show that YjgM upregulates the crotonylation of the substrate protein PmrA, thereby boosting PmrA’s affinity for binding to the promoter of eptA, which, in turn, promotes EptA expression and confers polymyxin resistance in E. coli. Additionally, we discover that PmrA’s crucial crotonylation site and functional site is Lys 164. These significant discoveries highlight the role of crotonylation in bacterial drug resistance and offer a fresh perspective on creating antibacterial compounds.
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•YjgM functions as a crotonyltransferase in Escherichia coli•Crotonylation proteomics reveals differentially crotonylated proteins in PMB-R•YjgM promotes bacterial polymyxin resistance via the crotonylation of PmrA•Crotonylation promotes PmrA’s binding ability to the eptA promoter
Zhuang et al. find that YjgM is a crotonyltransferase in Escherichia coli. YjgM improves the binding affinity between the polymyxin-resistant protein PmrA and the eptA promoter by increasing the crotonoylation level of PmrA, thereby encouraging the expression of eptA, resulting in the development of polymyxin resistance in E. coli.
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