28 research outputs found

    Transcriptome and Network Changes in Climbers at Extreme Altitudes

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    Extreme altitude can induce a range of cellular and systemic responses. Although it is known that hypoxia underlies the major changes and that the physiological responses include hemodynamic changes and erythropoiesis, the molecular mechanisms and signaling pathways mediating such changes are largely unknown. To obtain a more complete picture of the transcriptional regulatory landscape and networks involved in extreme altitude response, we followed four climbers on an expedition up Mount Xixiabangma (8,012 m), and collected blood samples at four stages during the climb for mRNA and miRNA expression assays. By analyzing dynamic changes of gene networks in response to extreme altitudes, we uncovered a highly modular network with 7 modules of various functions that changed in response to extreme altitudes. The erythrocyte differentiation module is the most prominently up-regulated, reflecting increased erythrocyte differentiation from hematopoietic stem cells, probably at the expense of differentiation into other cell lineages. These changes are accompanied by coordinated down-regulation of general translation. Network topology and flow analyses also uncovered regulators known to modulate hypoxia responses and erythrocyte development, as well as unknown regulators, such as the OCT4 gene, an important regulator in stem cells and assumed to only function in stem cells. We predicted computationally and validated experimentally that increased OCT4 expression at extreme altitude can directly elevate the expression of hemoglobin genes. Our approach established a new framework for analyzing the transcriptional regulatory network from a very limited number of samples

    Two ultraviolet radiation datasets that cover China

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    Ultraviolet (UV) radiation has significant effects on ecosystems, environments, and human health, as well as atmospheric processes and climate change. Two ultraviolet radiation datasets are described in this paper. One contains hourly observations of UV radiation measured at 40 Chinese Ecosystem Research Network stations from 2005 to 2015. CUV3 broadband radiometers were used to observe the UV radiation, with an accuracy of 5%, which meets the World Meteorology Organization's measurement standards. The extremum method was used to control the quality of the measured datasets. The other dataset contains daily cumulative UV radiation estimates that were calculated using an all-sky estimation model combined with a hybrid model. The reconstructed daily UV radiation data span from 1961 to 2014. The mean absolute bias error and root-mean-square error are smaller than 30% at most stations, and most of the mean bias error values are negative, which indicates underestimation of the UV radiation intensity. These datasets can improve our basic knowledge of the spatial and temporal variations in UV radiation. Additionally, these datasets can be used in studies of potential ozone formation and atmospheric oxidation, as well as simulations of ecological processes

    Paleokarst reservoirs and gas accumulation in the Jingbian field, Ordos Basin

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    The Jingbian gas field in central Ordos Basin, with a proven initial in place gas reserve of approximately 11 trillion cubic meters, is the largest paleokarst carbonate gas field in China. Paleokarst in Ordovician strata of central Ordos most commonly occurs in the paleo-weathering surface of the O1m5 member of the Majiagou Formation. The karst intervals are generally proximal to the sub-Upper Paleozoic unconformity; however, dissolution features in strata well below that exposure surface are possibly related to intra-Majiagou Formation unconformities. The quality of gas reservoirs are initially controlled by sedimentary facies, with anhydrite-bearing dolomite flat facies being the most favorable zones for dissolution and dolomitization to form karst and large/small dissolution cavities. The gases are generally dry, derived dominantly from the overlying Carboniferous–Permian coal measures. The gases are accumulated in stratigraphic traps related to karst paleo-geomorphology and lithologic traps associated with late diagenetic features of carbonate rocks. Although the precise timings of the thermal events during the evolution of the Ordos Basin are still subject to considerable debate, there is a general consensus that events occurring during the Yenshanian orogeny (150–115 Ma) were the most important for the Paleozoic source rocks. It appears that two episodes of hydrocarbon charge have occurred in the Ordovician gas reservoirs in the Jingbian field

    TESConf_2022_paper_4441

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    Human-Robot Collaboration (HRC) has been proposed to add flexibility to traditional production systems. Digital Twin (DT) has been integrated with HRC for safety collaboration. The human behaviour model is an essential part of the DT. This paper aims to identify a research gap and possible solutions for human behaviour modelling in HRC. Therefore, this paper reviews human behaviour studies in HRC and ethology. The results show that the current HRC focuses on recognizing and monitoring human behaviour, but a deep analysis of human behaviour is still lacking. Computational Ethology (CE) has the potential to be applied to HRC to model human behaviour in a structured manner. Future work could focus on transferring knowledge from CE and designing robot control strategies for HRC safety

    A Dramatic Marine Environment Change in the Beibu Gulf of the South China Sea around 3.2 kyr BP

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    AbstractThe profile geochemical characteristics of a seafloor sediment core, collected from the Beibu Gulf of the South China Sea, have been investigated in terms of the sediment grain size, the content of major and trace elements, the total organic carbon (TOC) and organic nitrogen (TN), and the carbon isotopic composition of organic matter (δ13Corg) and AMS 14C dating. These results show that the core sediments were deposited since 11.3 kyr BP and the profile could be clearly divided into the lower and upper sediment section based on geochemical characteristics. The lower section covers the depth of 86 cm to 200 cm and was deposited from 3.2 to 11.3 kyr BP, while the upper section is at the depth of 4 to 86 cm and represents sediments from 0.2 to 3.2 kyr BP. The upper section sediments are charcteristized by a much finer grain size and a clearly positive deviation of the δ13Corg value. Obviously, the overall profile geochemical characteristics indicate that the upper section was deposited under a significantly deeper seawater depth associated with a relatively weaker hydrodynamic and a better preservation condition for organic matter, while the low section was deposited under a relatively shallow seawater depth with the relatively stronger hydrodynamic condition and a relatively poor preservation condition for organic matter. Finally, it is suggested that the transition between the lower section and the upper section occurring around 3.2 kyr BP was mostly likely due to a dramatic marine environmental change caused by the rapid seafloor subsidence associated with the further expansion of the Qiongzhou Strait. And further multidisciplinary studies are needed to better reveal and understand different aspects of the significance of this marine environment change in the Beibu Gulf of the South China Sea

    Functionalized selenium nanoparticles for targeted siRNA delivery silence Derlin1 and promote antitumor efficacy against cervical cancer

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    Small interfering RNA (siRNA) exhibits great potential as a novel therapeutic option due to its highly sequence-specific ability to silence genes. However, efficient and safe delivery carriers are required for developing novel therapeutic paradigms. Thus, the successful development of efficient delivery platforms for siRNA is a crucial issue for the development of siRNA-based drugs in cancer treatments. In this study, biocompatible selenium nanoparticles (SeNPs) were loaded with RGDfC peptide to fabricate tumor-targeting gene delivery vehicle RGDfC-SeNPs. Subsequently, RGDfC-SeNPs were loaded with Derlin1-siRNA to fabricate RGDfC-Se@siRNA, which are functionalized selenium nanoparticles. RGDfC-Se@siRNA showed greater uptake in HeLa cervical cancer cells in comparison with that in human umbilical vein endothelial cells (HUVECs), verifying the RGDfC-mediated specific uptake of RGDfC-Se@siRNA. RGDfC-Se@siRNA was capable of entering HeLa cells via clathrin-associated endocytosis, and showed faster siRNA release in a cancer cell microenvironment in comparison with a normal physiological environment. qPCR and western blotting assays both indicated that RGDfC-Se@siRNA exhibited an obvious gene silencing efficacy in HeLa cells. RGDfC-Se@siRNA suppressed the invasion, migration and the proliferation of HeLa cells, and triggered HeLa cell apoptosis. Moreover, RGDfC-Se@siRNA induced the disruption of mitochondrial membrane potentials. Meanwhile, RGDfC-Se@siRNA enhanced the generation of reactive oxygen species (ROS) in HeLa cell, suggesting that mitochondrial dysfunction mediated by ROS might play a significant role in RGDfC-Se@siRNA-induced apoptosis. Interestingly, RGDfC-SeNPs@siRNA exhibited significant antitumor activity in a HeLa tumor-bearing mouse model. Additionally, RGDfC-SeNPs@siRNA is nontoxic to main organ of mouse. The above results indicate that RGDfC-Se@siRNA provides a promising potential for cervical cancer therapy

    Redistribution characteristics of atmospheric precipitation in different spatial levels of Guangzhou urban typical forests in southern China

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    The aims of the present study were to determine the pH variation and chemical feature of atmospheric precipitation during the research period. We also investigated the redistribution characteristics of rainfall while passing through the canopy layer, leaf-litter layer and soil layer, successively to quantify the acid rain buffering capacity of these spatial levels in the evergreen broadleaved forest (EBF), deciduous broadleaved forest (DBF) and coniferous forest (CF) in Guangzhou urban area, China. Results showed that the rainfall was typically acidic, and the acid rain type in Guangzhou urban area is converted from sulfuric acid type to mixed type of sulfuric acid and nitric acid. The major ions from the canopy to the forest floor differed within the three forest types. However, the enrichment phenomenon of base cations in soil leachate in EBF and DBF implied that nutrient loss was more serious in the broadleaved forest than in the coniferous forest. Variability of ionic concentration and pH in the vertical sequence of different tree species showed that the net ion concentration variation index has a significant conic relationship with ne pH change rate. We also built an acid rain buffering index, which combines the neutralization and interception effects of vegetation to acid rainfall. The present results indicated that the three forest types in urban Guangzhou all have certain buffering capacity to acid rain, and following the order: DBF > EBF > CF. In the meanwhile, the forest canopy is the biggest acid rain buffer in urban Guangzhou, following by the soil
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