96 research outputs found

    Yellow–colored mesoporous pure titania and its high stability in visible light photocatalysis

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    AbstractYellow–colored pure titania with a mesoporous structure was prepared by the aggregate of titania nanocrystals, which were stabilized by exfoliated titanate nanosheets via an electrostatic interaction. X–ray diffraction patterns and images of transmission electron microscope confirm that titanate sheets are randomly dispersed into the assembled titania nanocrystals without forming any self–restacked phase. This nanocrystals–nanosheets composite exhibits a mesoporous structure with pore size of ~6.5nm and surface area of 236.3m2g−1. Greatly different from the UV–responded properties of titania nanocrystals and titanate nanosheets, the absorption edge of nanocomposite red–shifts to visible light region. The visible light photocatalytic tests demonstrate that this nanocomposited titania shows excellent activity for the degradation of organic dyes, as well as a colorless organic pollutant of 2, 4–dichlorophenol. The possible photocatalytic mechanism that photogenerated holes as the mainly oxidant species in photocatalysis is proposed based on the trapping experiments of hydroxyl radicals or photogenerated holes. Moreover, as the nanocomposite depicts an extreme stability, no obvious deactivation occurs after five cycles

    Changes in global climate heterogeneity under the 21st century global warming

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    Publisher Copyright: © 2021 The Author(s)Variations in climate types are commonly used to describe changes in natural vegetation cover in response to global climate change. However, few attempts have been made to quantify the heterogeneous dynamics of climate types. In this study, based on the Coupled Model Intercomparison Project phase 5 (CMIP5) historical and representative concentration pathway (RCP) runs from 18 global climate models, we used Shannon's Diversity Index (SHDI) and Simpson's Diversity Index (SIDI) to characterise of global climate heterogeneity from a morphological perspective. Our results show that global climate heterogeneity calculated by the SHDI/SIDI indices decreased from 1901 to 2095 at a significance level of 0.01. As radiative forcing intensified from RCP 2.6 to 8.5, the SHDI/SIDI decreased significantly. Furthermore, we observed that the spatial distribution of global climate heterogeneity was significantly reduced, with a pronounced latitudinal trend. Sensitivity analysis indicated that the temperature increase played a more significant role in reducing global climate heterogeneity than precipitation under the three warming scenarios, which is possibly attributed to anthropogenic forcing. Our findings suggest that the dynamics of global climate heterogeneity can be an effective means of quantifying global biodiversity loss.Peer reviewe

    Identification of QTNs Controlling Seed Protein Content in Soybean Using Multi-Locus Genome-Wide Association Studies

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    Protein content (PC), an important trait in soybean (Glycine max) breeding, is controlled by multiple genes with relatively small effects. To identify the quantitative trait nucleotides (QTNs) controlling PC, we conducted a multi-locus genome-wide association study (GWAS) for PC in 144 four-way recombinant inbred lines (FW-RILs). All the FW-RILs were phenotyped for PC in 20 environments, including four locations over 4 years with different experimental treatments. Meanwhile, all the FW-RILs were genotyped using SoySNP660k BeadChip, producing genotype data for 109,676 non-redundant single-nucleotide polymorphisms. A total of 129 significant QTNs were identified by five multi-locus GWAS methods. Based on the 22 common QTNs detected by multiple GWAS methods or in multiple environments, pathway analysis identified 8 potential candidate genes that are likely to be involved in protein synthesis and metabolism in soybean seeds. Using superior allele information for 22 common QTNs in 22 elite and 7 inferior lines, we found higher superior allele percentages in the elite lines and lower percentages in the inferior lines. These findings will contribute to the discovery of the polygenic networks controlling PC in soybean, increase our understanding of the genetic foundation and regulation of PC, and be useful for molecular breeding of high-protein soybean varieties

    Smithian platform-bearing gondolellid conodonts from Yiwagou Section, northwestern China and implications for their geographic distribution in the Early Triassic

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    Abundant platform-bearing gondolellid conodonts, including Scythogondolella mosheri (Kozur and Mostler), Sc. phryna Orchard and Zonneveld, and Sc. cf. milleri (Müller), have been discovered from the Yiwagou Section of Tewo, together with Novispathodus waageni waageni (Sweet) and Nv. w. eowaageni Zhao and Orchard. This is the first report of Smithian platform-bearing gondolellids from the Paleo-Tethys region. In addition, Eurygnathodus costatus Staesche, E. hamadai(Koike), Parafurnishius xuanhanensis Yang et al., and the genera Pachycladina Staesche, Parachirognathus Clark, and Hadrodontina Staesche have also been recovered from Dienerian to Smithian strata at Yiwagou Section. Three conodont zones are established, in ascending order: Eurygnathodus costatus-E. hamadai Assemblage Zone, Novispathodus waageni-Scythogondolella mosheri Assemblage Zone, and the Pachycladina-Parachirognathus Assemblage Zone. The platform-bearing gondolellids were globally distributed just after the end-Permian mass extinction, but the formerly abundant Clarkina Kozur disappeared in the late Griesbachian. Platform-bearing gondolellids dramatically decreased to a minimum of diversity and extent in the Dienerian before recovering in the Smithian. Scythogondolella Kozur, probably a thermophilic and eurythermic genus, lived in all latitudes at this time whereas other genera did not cope with Smithian high temperatures and so became restricted to the high-latitude regions. However, the maximum temperature in the late Smithian likely caused the extinction of almost all platform-bearing gondolellids. Finally, the group returned to equatorial regions and achieved global distribution again in the cooler conditions of the late Spathian. We conclude that temperature (and to a lesser extent oxygen levels) exerted a strong control on the geographical distribution and evolution of platform-bearing gondolellids in the Early Triassic

    Protection of Human Umbilical Vein Endothelial Cells against Oxidative Stress by MicroRNA-210

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    Oxidative stress induces endothelial cell apoptosis and promotes atherosclerosis development. MicroRNA-210 (miR-210) is linked with apoptosis in different cell types. This study aimed to investigate the role of miR-210 in human umbilical vein endothelial cells (HUVECs) under oxidative stress and to determine the underlying mechanism. HUVECs were treated with different concentrations of hydrogen peroxide (H2O2), and cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and ATP assay. To evaluate the role of miR-210 in H2O2-mediated apoptosis, gain-and-loss-of-function approaches were used, and the effects on apoptosis and reactive oxygen species (ROS) level were assayed using flow cytometry. Moreover, miR-210 expression was detected by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), and expression of the following apoptosis-related genes was assessed by qRT-PCR and Western blot at the RNA and protein level, respectively: caspase-8-associated protein 2 (CASP8AP2), caspase-8, and caspase-3. The results showed that H2O2 induced apoptosis in HUVECs in a dose-dependent manner and increased miR-210 expression. Overexpression of miR-210 inhibited apoptosis and reduced ROS level in HUVECs treated with H2O2. Furthermore, miR-210 downregulated CASP8AP2 and related downstream caspases at protein level. Thus, under oxidative stress, miR-210 has a prosurvival and antiapoptotic effect on HUVECs by reducing ROS generation and downregulating the CASP8AP2 pathway

    Integrated Sr isotope variations and global environmental changes through the Late Permian to early Late Triassic

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    New 87Sr/86Sr data based on 127 well-preserved and well-dated conodont samples from South China were measured using a new technique (LA-MC-ICPMS) based on single conodont albid crown analysis. These reveal a spectacular climb in seawater 87Sr/86Sr ratios during the Early Triassic that was the most rapid of the Phanerozoic. The rapid increase began in Bed 25 of the Meishan section (GSSP of the Permian–Triassic boundary, PTB), and coincided closely with the latest Permian extinction. Modeling results indicate that the accelerated rise of 87Sr/86Sr ratios can be ascribed to a rapid increase (>2.8×) of riverine flux of Sr caused by intensified weathering. This phenomenon could in turn be related to an intensification of warming-driven runoff and vegetation die-off. Continued rise of 87Sr/86Sr ratios in the Early Triassic indicates that continental weathering rates were enhanced >1.9 times compared to those of the Late Permian. Continental weathering rates began to decline in the middle–late Spathian, which may have played a role in the decrease of oceanic anoxia and recovery of marine benthos. The 87Sr/86Sr values decline gradually into the Middle Triassic to an equilibrium values around 1.2 times those of the Late Permian level, suggesting that vegetation coverage did not attain pre-extinction levels thereby allowing higher runoff

    Advances in lung adenocarcinoma: A novel perspective on prognoses and immune responses of CENPO as an oncogenic superenhancer

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    Lung adenocarcinoma (LUAD) is the most prevalent form of lung cancer globally, and its treatment remains a significant challenge. Therefore, it is crucial to comprehend the microenvironment to improve therapy and prognosis urgently. In this study, we utilized bioinformatic methods to analyze the transcription expression profile of patient samples with complete clinical information from the TCGA-LUAD datasets. To validate our findings, we also analyzed the Gene Expression Omnibus (GEO) datasets. The super-enhancer (SE) was visualized using the peaks of the H3K27ac and H3K4me1 ChIP-seq signal, which were identified by the Integrative Genomics Viewer (IGV). To further investigate the role of Centromere protein O (CENPO) in LUAD, we conducted various assays including Western blot, qRT-PCR, flow cytometry, wound healing and transwell assays to assess the cell functions of CENPO in vitro. The overexpression of CENPO is linked to a poor prognosis in patients with LUAD. Strong signal peaks of H3K27ac and H3K4me1 were also observed near the predicted SE regions of CENPO. CENPO was found to be positively associated with the expression levels of immune checkpoints and drug IC50 value (Roscovitine and TGX221), but negatively associated with the fraction levels of several immature cells and drug IC50 value (CCT018159, GSK1904529A, Lenaildomide, and PD-173074). Additionally, CENPO-associated prognostic signature (CPS) was identified as an independent risk factor. The high-risk group for LUAD is identified based on CPS enrichment, which involved not only endocytosis that transfers mitochondria to promote cell survival in response to chemotherapy but also cell cycle promotion that leads to drug resistance. The removal of CENPO significantly suppressed metastasis and induced arrest and apoptosis of LUAD cells. The involvement of CENPO in the immunosuppression of LUAD provides a prognostic signature for LUAD patients

    Research Progress of Applying Infrared Spectroscopy Technology for Detection of Toxic and Harmful Substances in Food

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    In recent years, food safety incidents have been frequently reported. Food or raw materials themselves contain substances that may endanger human health and are called toxic and harmful substances in food, which can be divided into endogenous, exogenous toxic, and harmful substances and biological toxins. Therefore, realizing the rapid, efficient, and nondestructive testing of toxic and harmful substances in food is of great significance to ensure food safety and improve the ability of food safety supervision. Among the nondestructive detection methods, infrared spectroscopy technology has become a powerful solution for detecting toxic and harmful substances in food with its high efficiency, speed, easy operation, and low costs, while requiring less sample size and is nondestructive, and has been widely used in many fields. In this review, the concept and principle of IR spectroscopy in food are briefly introduced, including NIR and FTIR. Then, the main progress and contribution of IR spectroscopy are summarized, including the model’s establishment, technical application, and spectral optimization in grain, fruits, vegetables, and beverages. Moreover, the limitations and development prospects of detection are discussed. It is anticipated that infrared spectroscopy technology, in combination with other advanced technologies, will be widely used in the whole food safety field

    Synthesis of geochemical techniques to identify the origin and multistage evolution of saline water in a complex geothermal system

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    Elucidating brine origin and evolution is a fundamental but not easy task especially for coastal geothermal systems with possible marine constituents and multistage evolution, as subsequently physical, chemical and biological alteration processes may mask the original and early-stage signatures. Here chemical and isotopic characteristics of water (D and 18O) and dissolved constituents (13C, 14C, 11B and 87Sr/86Sr) have been utilized to investigate the source and multistage evolution of the Jimo coastal geothermal system in eastern China, with dramatic differences of geochemical characteristics observed within a 0.2 km2 area. Results show that geothermal water is derived from paleo-meteoric water and has undergone a 3-stages evolution that involves: (1) Dissolution of marine halite and potash salts in the deep reservoir; (2) Water-rock reactions especially cation exchange produces a Cl-Na-Ca type water as deep geothermal water upwells along the fault zone; (3) A minor (<0.3%) addition of fossil seawater to the shallow aquifer that produces Cl-Na type waters in the west, whereas sulfide oxidation and dissolution of aluminosilicate and carbonates in the east produces Cl-Na-Ca type waters. The methodology utilized in this study offers a means of examining other similar complex geochemical systems having a multistage evolution
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