Owing to the excellent sensitivity to gases, metal-oxide semiconductors (MOS) are widely used as materials for gas sensing. Usually, MOS gas sensors have some common shortages, such as relatively ...poor selectivity and high operating temperature. Graphene has drawn much attention as a gas sensing material in recent years because it can even work at room temperature, which reduces power consumption. However, the low sensitivity and long recovery time of the graphene-based sensors limit its further development. The combination of metal-oxide semiconductors and graphene may significantly improve the sensing performance, especially the selectivity and response/recovery rate at room temperature. In this review, we have summarized the latest progress of graphene/metal-oxide gas sensors for the detection of NO
, NH
, CO and some volatile organic compounds (VOCs) at room temperature. Meanwhile, the sensing performance and sensing mechanism of the sensors are discussed. The improved experimental schemes are raised and the critical research directions of graphene/metal-oxide sensors in the future are proposed.
In order to detect low concentrations of volatile organic compounds (VOCs) for the early diagnosis of lung cancer, sensors based on hollow spheres of In
2
O
3
were prepared through the soft template ...method. Ag nanoparticle decorated In
2
O
3
composites were synthesized via dipping and annealing. The microstructure, phase composition, element distribution, and state of Ag were analyzed by the scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). The gas sensing tests showed that Ag-In
2
O
3
sensors had the highest response to isopropanol at 300 °C. The best response of Ag-In
2
O
3
composite sensor was 5.2, which had a significant improvement compared with only In
2
O
3
. Moreover, the response and recovery time of Ag-In
2
O
3
composite sensor was significantly shortened. The improved sensing properties of Ag-In
2
O
3
composite sensor could be attributed to the Schottky barrier created at Ag-In
2
O
3
interface and catalytical effect of Ag.
Hydroxyapatite coatings were deposited on stainless steel substrates. The arc current was varied to study its effect on the coating crystallinity. The crystallinity was calculated according to the ...XRD patterns via Jade 6.0 software and the full width at half maximum (FWHM) of Raman peak at 962cm−1. The FE-SEM images showed that HA coatings had rod-like nanostructures and agglomerated into microspheres. The XRD patterns indicated that the as-sprayed coatings were composed of HA and some decomposition phases. Micro-Raman spectroscopies demonstrated that the main phase in the coatings was HA. The results showed that the crystallinity was increased from 68.68% to 76.84% while the FWHM varied from 9.74 to 6.38cm−1, when the arc current increased from 400A to 600A. The selected area electron diffraction (SEAD) patterns were used to analyze the crystallinity qualitatively, and the results agreed with the conclusions of XRD and FWHM of Raman peak.
The detection of lung cancer via the analysis of volatile organic compounds (VOCs) in exhaled breath has attracted a lot of attention as it is simple and non-invasive for the patients. Among the ...numerous VOCs exist in the breath, isopropanol is believed to be an important biomarker that can help to discriminate between healthy and unhealthy people. In this work, a highly sensitive Fe-doped ZnO nanoneedles-based gas sensor was studied for the detection of isopropanol at low concentrations (below 10 ppm). The pure and Fe-doped ZnO were synthesized via a hydrothermal method and spray-coated onto an alumina substrates equipped with a pair of gold interdigitated electrodes. The morphologies of the sensing layers were characterized by SEM, while the phase structure and composition were determined by XRD. The sensing properties of pure and Fe-doped ZnO were investigated under different temperatures and concentrations. It is found that Fe doping significantly increased the sensing performance of ZnO nanoneedles. The optimal doping concentration of Fe is 5 at% for isopropanol detection, and the optimal working temperature is 275 °C. The sensor showed a high response to 250 ppb isopropanol, together with high stability under different humidity levels.
We aimed to study the involvement of ferroptosis in the pathogenesis of bronchopulmonary dysplasia (BPD) by conducting bioinformatics analyses and identifying and validating the associated ...ferroptosis-related genes to explore new directions for treating BPD. The dataset GSE32472 on BPD was downloaded from the public genome database. Using R language, differentially expressed genes (DEGs) between the BPD and normal group were screened. In the present study, we adopted weighted gene correlation network analysis (WGCNA) for identifying BPD-related gene modules and ferroptosis-related genes were extracted from FerrDb. Their results were intersected to obtain the hub genes. After that, to explore the hub gene-related signaling pathways, the hub genes were exposed to gene ontology enrichment analysis. With the purpose of verifying the mRNA expression of the hub genes, a single-gene gene set enrichment analysis and quantitative reverse transcription polymerase chain reaction were conducted. Immune cell infiltration in BPD was analyzed using the CIBERSORT inverse fold product algorithm. A total of 606 DEGs were screened. WGCNA provided the BPD-related gene module darkgreen4. The intersection of DEGs, intramodular genes, and ferroptosis-related genes revealed six ferroptosis-associated hub genes (ACSL1, GALNT14, WIPI1, MAPK14, PROK2, and CREB5). Receiver operating characteristic curve analysis demonstrated that the hub genes screened for BPD were of good diagnostic significance. According to the results of immune infiltration analysis, the proportions of CD8, CD4 naive, and memory resting T cells and M2 macrophage were elevated in the normal group, and the proportions of M0 macrophage, resting mast cell, and neutrophils were increased in the BPD group. A total of six ferroptosis-associated hub genes in BPD were identified in this study, and they may be potential new therapeutic targets for BPD.
Depth-image-based rendering (DIBR) has become an accessible rendering technology for 3D video. A variety of digital watermarking methods have been proposed to protect the copyright of DIBR 3D video ...works. However, the robustness and imperceptibility of the existing methods need to be improved. Therefore, we apply the DIBR rendering features to propose a watermarking method to enhance the watermarking effect. First, to improve the robustness, we combine the DIBR rendering rules to construct steady feature data as the selection criterion of watermark embedding position. We detect the scale invariable feature transformation (SIFT) feature points from centre views and match them in every two adjacent views. Each two matched feature points construct one matching vector. The gradient-probability distributions of the vectors are used as the feature data to determine the watermark embedding position. Thus, the embedding positions are robust to the affine transformation and geometric attacks, and the watermark robustness improved. Second, to improve the imperceptibility, we design a joint watermark extraction strategy based on the similarity of the rendered left and right images. The watermark data are embedded into the centre view with low embedding strength and jointly extracted from the left and right images. This strategy guarantees the extraction accuracy while reducing the impact of watermark embedding on the original centre view. Experimental data show that the proposed method has good robustness and imperceptibility.
Hollow spheres of pure ZnFe2O4 and of composites of ZnFe2O4 and reduced graphene oxide (rGO) with different rGO content were prepared via a simple solvothermal method followed by a high-temperature ...annealing process in an inert atmosphere. The X-ray diffraction analysis confirmed that the introduction of rGO had no effect on the spinel structure of ZnFe2O4. In addition, the results of field-emission scanning electron microscopy and (high-resolution) transmission electron microscopy indicated that the synthesized samples had the structure of hollow spheres distributed uniformly onto rGO nanosheets. The diameters of the spheres were determined as about 600–1000 nm. The gas sensing test revealed that the introduction of rGO improved the performance of the sensing of acetone to low concentration, and the ZnFe2O4/rGO composite gas sensor containing 0.5 wt % of rGO exhibited a high sensitivity in sensing test using 0.8–100 ppm acetone at 200 °C. The response of the 0.5 wt % ZnFe2O4/rGO sensor to 0.8 ppm acetone was 1.50, and its response to 10 ppm acetone was 8.18, which is around 2.6 times more pronounced than the response of pure ZnFe2O4 (10 ppm, 3.20). Moreover, the sensor showed a wide linear range and good selectivity.
Augmented Renal Clearance (ARC) refers to the increased renal clearance of circulating solute in critically ill patients. In this study, the analytical research method of transcriptomics combined ...with metabolomics was used to study the pathogenesis of ARC at the transcriptional and metabolic levels. In transcriptomics, 534 samples from 5 datasets in the Gene Expression Omnibus database were analyzed and 834 differential genes associated with ARC were obtained. In metabolomics, we used Ultra-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry to determine the non-targeted metabolites of 102 samples after matching propensity scores, and obtained 45 differential metabolites associated with ARC. The results of the combined analysis showed that purine metabolism, arginine biosynthesis, and arachidonic acid metabolism were changed in patients with ARC. We speculate that the occurrence of ARC may be related to the alteration of renal blood perfusion by LTB4R, ARG1, ALOX5, arginine and prostaglandins E2 through inflammatory response, as well as the effects of
,
,
,
, NMDAR, glutamate and cAMP on renal capillary wall permeability.
Ganzi Prefecture in Western China is situated geographically at the transition regions between Tibetan Plateau and Sichuan Basin in a highly tectonically active boundary area between the India and ...Eurasia plates. The region hosts various hot springs that span a wide range of temperature from 30 to 98 °C and are located at high altitude (up to 4200 m above sea level) in the region of large geothermal anomalies and active Xianshuihe slip-fault that has been active since Holocene. The site represents a biodiversity reservoir for thermophiles, yet their diversity and relationship to geochemical parameters are largely unknown. In the present work, bacterial diversity and community structure in 14 hot springs of Ganzi were investigated using Illumina MiSeq sequencing.
Bacterial community compositions were evidently distinct among the 14 hot springs, and the bacterial communities in hot springs were majorly abundant in phyla Aquificae, Cyanobacteria and Proteobacteria. Both clustering and PCoA analysis suggested the existence of four bacterial community patterns in these hot springs. Temperature contributed to shaping bacterial community structure of hot springs as revealed by correlation analysis. Abundant unassigned-genus sequences detected in this study strongly implied the presence of novel genera or genetic resources in these hot springs.
The diversity of hot springs of Ganzi prefecture in Western Sichuan, China is evidently shaped by temperature. Interestingly disproportionally abundant unassigned-genus sequences detected in this study show indicate potential of novel genera or phylotypes. We hypothesize that frequent earthquakes and rapidly changing environment might have contributed to evolution of these potentially new lineages. Overall, this study provided first insight into the bacterial diversity of hot springs located in Western Sichuan, China and its comparison with other similar communities worldwide.
Reperfusion injury is still a major challenge that impedes neuronal survival in ischemic stroke. However, the current clinical treatments are remained on single pathological process, which are due to ...lack of comprehensive neuroprotective effects. Herein, a macrophage‐disguised honeycomb manganese dioxide (MnO2) nanosphere loaded with fingolimod (FTY) is developed to salvage the ischemic penumbra. In particular, the biomimetic nanoparticles can accumulate actively in the damaged brain via macrophage‐membrane protein‐mediated recognition with cell adhesion molecules that are overexpressed on the damaged vascular endothelium. MnO2 nanosphere can consume excess hydrogen peroxide (H2O2) and convert it into desiderated oxygen (O2), and can be decomposed in acidic lysosome for cargo release, so as to reduce oxidative stress and promote the transition of M1 microglia to M2 type, eventually reversing the proinflammatory microenvironment and reinforcing the survival of damaged neuron. This biomimetic nanomedicine raises new strategy for multitargeted combined treatment of ischemic stroke.
Macrophage‐disguised FTY‐loaded MnO2 nanoparticles (Ma@(MnO2+FTY)) are engineered to salvage the ischemic penumbra. Nanoparticles can accumulate actively in the ischemic region to protect neurons directly via consuming ROS and generating O2. In addition, the nanoparticles can also reverse the proinflammatory microenvironment by promoting the phenotypic transition of microglia through multiple signaling pathways, increasing the protection effects on damaged neurons.
PDF
