Bioavailable transition trace elements, such as soluble iron (Fes) and soluble manganese (Mns) in aerosols, play a crucial role in atmospheric sulfate formation and marine ecosystems. In this study ...conducted during the spring of 2017 in Qingdao, a coastal city in Northern China, we applied a combined approach of multiple linear regression (MLR) incorporating the results of positive matrix factorization (PMF) to estimate the solubility of Fe and Mn from various sources. PMF analysis showed that dust was the largest contributor to total Fe (FeT) (45.5 %), followed by non-ferrous smelting (20.3 %) and secondary formation processes (17.8 %). However, secondary formation processes (33.2 %), vehicle exhaust (19.3 %) and aqueous-phase processes (19.0 %) were found to be the primary contributors to Fes. For total Mn (MnT) and Mns, dust (21.2 % ∼ 35.0 %), secondary formation processes (20.3 % ∼ 25.6 %) and industry (12.6 % ∼ 16.3 %) were identified as the dominant contributors. The solubilities of Fe and Mn varied significantly depending on their sources. Interestingly, nitrate played a more pronounced role than sulfate in facilitating the dissolution of Fe and Mn during the acid processing due to the high molar ratio of NO3−/2SO42− (1.72 ± 0.54) under the average RH of 56 % ± 15 %. This phenomenon suggested that the acid processing was primarily triggered by nitrate formation due to the low deliquescence relative humidity (DRH) of nitrate. Additionally, we discovered that the catalytic oxidation of SO2 in aerosol water was primarily driven by Fe rather than Mn, serving as a more significant pathway for sulfate formation within a pH range of 2.0 to 4.4. These findings provide valuable insights into the impact of acidification on the dissolution of Fe and Mn under conditions of moderate RH in the real ambient atmosphere with the increasing of NO3−/2SO42− molar ratio.
Display omitted
•Multiple linear regression was applied to the PMF results to estimate the solubility of Fe and Mn from different sources.•Nitrate played a key role in promoting Fe and Mn dissolution under the high molar ratio of NO3−/2SO42− and the moderate RH.•Fe, rather than Mn, acted as the primary catalyst for sulfate formation at a low pH range of 2.0–4.4 in spring.
Computed tomography (CT) scan is frequently used to detect hepatocellular carcinoma (HCC) in routine clinical practice. The aim of this study is to develop a deep-learning AI system to improve the ...diagnostic accuracy of HCC by analysing liver CT imaging data.
We developed a deep-learning AI system by training on CT images from 7512 patients at Henan Provincial Peoples' Hospital. Its performance was validated on one internal test set (Henan Provincial Peoples' Hospital, n = 385) and one external test set (Henan Provincial Cancer Hospital, n = 556). The area under the receiver-operating characteristic curve (AUROC) was used as the primary classification metric. Accuracy, sensitivity, specificity, precision, negative predictive value and F1 metric were used to measure the performance of AI systems and radiologists.
AI system achieved high performance in identifying HCC patients, with AUROC of 0.887 (95% CI 0.855-0.919) on the internal test set and 0.883 (95% CI 0.855-0.911) on the external test set. For internal test set, accuracy was 81.0% (76.8-84.8%), sensitivity was 78.4% (72.4-83.7%), specificity was 84.4% (78.0-89.6%) and F1 (harmonic average of precision and recall rate) was 0.824. For external test set, accuracy was 81.3% (77.8-84.5%), sensitivity was 89.4% (85.0-92.8%), specificity was 74.0% (68.5-78.9%) and F1 was 0.819. Compared with radiologists, AI system achieved comparable accuracy and F1 metric on internal test set (0.853 versus 0.818, P = 0.107; 0.863 vs. 0.824, P = 0.082) and external test set (0.805 vs. 0.793, P = 0.663; 0.810 vs. 0.814, P = 0.866). The predicted HCC risk scores by AI system in HCC patients with multiple tumours and high fibrosis stage were higher than those with solitary tumour and low fibrosis stage (tumour number: 0.197 vs. 0.138, P = 0.006; fibrosis stage: 0.183 vs. 0.127, P < 0.001). Radiologists' review showed that the accuracy of saliency heatmaps predicted by algorithms was 92.1% (95% CI: 89.2-95.0%).
AI system achieved high performance in the detection of HCC compared with a group of specialised radiologists. Further investigation by prospective clinical trials was necessitated to verify this model.
Iron carbide (Fe
3
C) has gained significant attention for use in energy storage applications. Furthermore, using a nano-scale metal as the catalyst can reduce the formation of a solid electrolyte ...interface (SEI), thus enhancing capacity. For these reasons, hierarchical Fe/Fe
3
C/C nanofibers are prepared by electrospinning with subsequent thermal treatment and used as the anodes for lithium ion batteries (LIBs). These anodes demonstrate a good rate and high capacities. At 0.1 A g
−1
, the Fe/Fe
3
C/C nanofiber electrode maintains 518 mA h g
−1
after 100 cycles. When tested at 1 A g
−1
, the discharge capacity gradually increases and reaches 663 mA h g
−1
after 1200 cycles. This work demonstrates the possibility to design and develop transition metal carbides (TMCs) for use in energy storage.
Abstract Bolt loosening detection is crucial for ensuring the safe operation of equipment. Loosened bolts are hard to detect, and if left undetected, it can lead to catastrophic failures, especially ...for numerous bolts in large-scale structures. Therefore, the development of distributed bolt monitoring method and related sensors is highly necessary. In this paper, a novel bolt preload sensor with self-temperature compensation is proposed, based on the strain distribution of the bolt head end face. This study enhances previous research by conducting a detailed analysis of strain distribution at the edge of the bolt head surface. The finite element analysis results show that the bolt preload has almost no effect on the circumferential strain in the edge region of bolt head surface. Based on this feature, the strain gauge is applied circumferentially along the edge of the bolt head face as a temperature compensation gauge. In this way, the measuring strain gauge and the temperature compensation gauge can be integrated on the surface of the bolt head, thus achieving self-temperature compensation for the sensor. An experimental device has been established and the experimental results show that the designed sensor has excellent linearity to the bolt preload and effective temperature compensation. For the monitoring of numerous bolts with a wide distribution, a wireless sensing network utilizing the proposed sensor has been designed. The proposed wireless bolt sensor is easy to install and replace, without redesigning or changing the existing structure, thus providing a simple and effective way to monitor large number of bolts with wide distribution.
Abstract
Although much attention has been paid to investigating and controlling air pollution in China, the trends of air-pollutant concentrations on a national scale have remained unclear. Here, we ...quantitatively investigated the variation of air pollutants in China using long-term comprehensive data sets from 2013 to 2017, during which Chinese government made major efforts to reduce anthropogenic emission in polluted regions. Our results show a significant decreasing trend in the PM2.5 concentration in heavily polluted regions of eastern China, with an annual decrease of ∼7% compared with measurements in 2013. The measured decreased concentrations of SO2, NO2 and CO (a proxy for anthropogenic volatile organic compounds) could explain a large fraction of the decreased PM2.5 concentrations in different regions. As a consequence, the heavily polluted days decreased significantly in corresponding regions. Concentrations of organic aerosol, nitrate, sulfate, ammonium and chloride measured in urban Beijing revealed a remarkable reduction from 2013 to 2017, connecting the decreases in aerosol precursors with corresponding chemical components closely. However, surface-ozone concentrations showed increasing trends in most urban stations from 2013 to 2017, which indicates stronger photochemical pollution. The boundary-layer height in capital cities of eastern China showed no significant trends over the Beijing–Tianjin–Hebei, Yangtze River Delta and Pearl River Delta regions from 2013 to 2017, which confirmed the reduction in anthropogenic emissions. Our results demonstrated that the Chinese government was successful in the reduction of particulate matter in urban areas from 2013 to 2017, although the ozone concentration has increased significantly, suggesting a more complex mechanism of improving Chinese air quality in the future.
DNA methylation is an important epigenetic mode of genomic DNA modification and plays a vital role in maintaining epigenetic content and regulating gene expression. Cytosine-5 DNA methyltransferase ...(C5-MTase) are the key enzymes in the process of DNA methylation. However, there is no systematic analysis of the C5-MTase in cotton so far, and the function of DNMT2 genes has not been studied.
In this study, the whole genome of cotton C5-MTase coding genes was identified and analyzed using a bioinformatics method based on information from the cotton genome, and the function of GhDMT6 was further validated by VIGS experiments and subcellular localization analysis.
33 C5-MTases were identified from three cotton genomes, and were divided into four subfamilies by systematic evolutionary analysis. After the protein domain alignment of C5-MTases in cotton, 6 highly conserved motifs were found in the C-terminus of 33 proteins involved in methylation modification, which indicated that C5-MTases had a basic catalytic methylation function. These proteins were divided into four classes based on the N-terminal difference, of which DNMT2 lacks the N-terminal regulatory domain. The expression of C5-MTases in different parts of cotton was different under different stress treatments, which indicated the functional diversity of cotton C5-MTase gene family. Among the C5-MTases, the GhDMT6 had a obvious up-regulated expression. After silencing GhDMT6 with VIGS, the phenotype of cotton seedlings under different stress treatments showed a significant difference. Compared with cotton seedlings that did not silence GhDMT6, cotton seedlings silencing GhDMT6 showed significant stress resistance.
The results show that C5-MTases plays an important role in cotton stress response, which is beneficial to further explore the function of DNMT2 subfamily genes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In recent years, winter PM2.5 and summer O3 pollution which often occurred with air stagnation condition has become a major concern in China. Thus, it is imperative to understand the air stagnation ...distribution in China and elucidate its impact on air pollution. In this study, three air stagnation indices were calculated according to atmospheric thermal and dynamics parameters using ERA5 data. Two improved indices were more suitable in China, and they displayed similar characteristics: most of the air stagnant days were found in winter, and seasonal distributions showed substantial regional heterogeneity. During stagnation events, flat west or northwest winds at 500 hPa and high pressure at surface dominated, with high relative humidity (RH) and temperature (T), weak winds in most regions. The pollutants concentrations on stagnant days were higher than those on non-stagnant days in most studied areas, with the largest difference of the 90th percentiles of maximum daily 8-h average (MDA8) O3 up to 62.2 μg m−3 in Pearl River Delta (PRD) and PM2.5 up to 95.8 μg m−3 in North China Plain (NCP). During the evolution of stagnation events, the MDA8 O3 concentrations showed a significant increase (6.0 μg m−3 day−1) in PRD and a slight rise in other regions; the PM2.5 concentrations and the frequency of extreme PM2.5 days increased, especially in NCP. Furthermore, O3 was simultaneously controlled by temperature and stagnation except for Xinjiang (XJ), with the average growth rate of 19.5 μg m−3 every 3 °C at 19 °C–31 °C. PM2.5 was dominated by RH and stagnation in northern China while mainly controlled by stagnation in southern China. Notably, the extremes of summer O3 (winter PM2.5) pollution was most associated with air stagnation and T at 25 °C–31 °C (air stagnation and RH >50%). The results are expected to provide important reference information for air pollution control in China.
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•Comparison of the three air stagnation indices in China.•Highest frequency of stagnant days in winter with substantial regional heterogeneity•O3 and PM2.5 increase by 12.0% and 16.8% on stagnant days on average.•Higher growth rate with the occurrence of stagnation for O3 (PM2.5) as temperature (humidity) increased•More extreme pollution under stagnation, temperature within 25–31 °C or humidity above 50%
High concentrations of heavy metals in the soil should be removed for environmental safety. Cadmium (Cd) is a heavy metal that pollutes the soil when its concentration exceeds 3.4 mg/kg. Although the ...potential use of cotton to remediate heavy Cd-polluted soils is known, little is understood about the molecular mechanisms of Cd tolerance. In this study, transcriptome analysis was used to identify Cd tolerance genes and their potential mechanisms in cotton. We exposed cotton plants to excess Cd and identified 4627 differentially expressed genes (DEGs) in the root, 3022 DEGs in the stem and 3854 DEGs in the leaves through RNA-Seq analysis. Among these genes were heavy metal transporter coding genes (ABC, CDF, HMA, etc.), annexin genes and heat shock genes (HSP), amongst others. Gene ontology (GO) analysis showed that the DEGs were mainly involved in the oxidation⁻reduction process and metal ion binding. The DEGs were mainly enriched in two pathways, the influenza A and pyruvate pathway. GhHMAD5, a protein containing a heavy-metal binding domain, was identified in the pathway to transport or to detoxify heavy metal ions. We constructed a
overexpression system in
that showed longer roots compared to control plants. GhHMAD5-silenced cotton plants showed more sensitivity to Cd stress. The results indicate that
is involved in Cd tolerance, which gives a preliminary understanding of the Cd tolerance mechanism in upland cotton. Overall, this study provides valuable information for the use of cotton to remediate soils polluted with Cd and potentially other heavy metals.
Rationale and objectives
To evaluate the predictive value of tumor and peritumor radiomics in the fatty acid binding protein 4 (FABP4) expression levels and overall survival in patients with ...hepatocellular carcinoma.
Materials and methods
The genomic data of HCC patients were obtained from The Cancer Genome Atlas. The Dual-area CT images of corresponding patients were downloaded from The Cancer Imaging Archive, for radiomics feature extraction, model construction and prognosis analysis. Simultaneously, using patients from Sichuan Provincial People’s Hospital, the prognostic value of the radiomics model in HCC patients was validated.
Results
In the TCIA database, the area under the curve (AUC) values of the volumes of interest (VOI)
whole
model in the training set and internal validation set were 0.812 and 0.754, respectively, and the AUC value of VOI
whole+periphery
in the training set and internal validation set were 0.866 and 0.779, respectively. In the VOI
whole
and the VOI
whole+periphery
model of the independent cohort, there were significant differences in OS between the high and low rad-score groups (
P
= 0.009,
P
= 0.021, respectively). Significant positive correlations can be observed between FABP4 expression and correlations with rad-score of VOI
whole
model (
r
= 0.691) and VOI
whole+periphery
model (
r
= 0.732) in the independent cohort.
Conclusion
Radiomics models of tumor and peritumor Dual-area CT images could predict stably the expression levels of FABP4 and may be helping in personalized treatment strategies.
Graphical abstract
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