51 research outputs found

    Global syndromes induced by changes in solutes of the world’s large rivers

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    Rivers are increasingly plagued by “syndromes”, i.e. salinization, mineralization, desalinization, acidification, alkalization, hardening and softening. A global look at river biogeochemistry reveals dramatically increased flux estimates and anthropogenic drivers of syndromes

    Overexpressed transient receptor potential vanilloid 1 (TRPV1) in lung adenocarcinoma harbours a new opportunity for therapeutic targeting

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    The specific biological function of transient receptor potential vanilloid 1 (TRPV1) in pathogenesis of lung adenocarcinoma (LUAD) remains unclear. In this study, TRPV1 expression in tumor tissues, primary cells and cell lines of LUAD, as well as the mechanism mediating its hyperexpression were systematically studied. Multiple models and techniques were adopted to elucidate the relationship between TRPV1 hyperexpression and tumor recurrence and metastasis. Results showed that TRPV1 expression was increased in tumor tissues and primary tumor cells of LUAD patients. The increased expression was associated with worse overall survival outcome and raised HIF1α levels. TRPV1 expression in A549 and NCI-H292 cells was increased after pretreatment with cigarette smoke extract or spermine NONOate. Moreover, A549 cells with TRPV1 overexpression has enhanced tumor growth rates in subcutaneous grafted tumor models, and increased intrapulmonary metastasis after tail vein infusion in nude BALB/c nude mice. Mechanistically, TRPV1 overexpression in A549 cells promoted HIF1α expression and nuclear translocation by promoting CREB phosphorylation and activation of NOS1-NO pathway, ultimately leading to accelerated cell proliferation and stronger invasiveness. In addition, based on photothermal effects, CuS-TRPV1 mAb effectively targeted and induced apoptosis of TRPV1-A549 cells both in vivo and in vitro, thereby mitigating tumor growth and metastasis induced by xenotransplantation of TRPV1-A549 cells. In conclusion, TRPV1 hyperexpression in LUAD is a risk factor for tumor progression and is involved in proliferation and migration of tumor cells through activation of HIF1α. Our study also attempted a new strategy inhibiting the recurrence and metastasis of LUAD: by CuS-TRPV1 mAb precisely kill TRPV1 hyperexpression cells through photothermal effects

    NIPTL-Novo: Non-isobaric peptide termini labeling assisted peptide de novo sequencing

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    A simple and effective de novo sequencing strategy assisted by non-isobaric peptide termini labeling, NIPTL-Novo, was established. The y-series ions and b-series ions of peptides can be clearly distinguished according to the different mass tags incorporated in N-terminus and C-terminus. This is helpful for improving the accuracy of peptide sequencing and increasing the sequencing speed. For the spectra commonly identified by both de novo sequencing and database searching software (Mascot or Maxquant), NIPTL-Novo gave identical result to more than 85% of these spectra. Furthermore, the quantitative profiling of the sample can be performed simultaneously along with de novo sequencing. Finally, this strategy can be applied to discover the peptides with potential mutation sites by combining with mass-defect based isotopic labeling

    Dynamic modeling of sliding joints based on transversely isotropic virtual material and deep neural network

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    Aiming at the problem that the current isotropic virtual material-based modeling method for dynamic modeling of sliding joints can hardly reflect the difference between normal and tangential mechanical properties, which restricts the modeling quality, a transversely isotropic material model is introduced to comprehensively describe the mechanical properties of sliding joints. Firstly, a dynamic model based on transversely isotropic virtual material and Deep Neural Network (DNN) is constructed to reflect the relationship between the dynamic parameters of transversely isotropic virtual material ( E τ , E n , μ τ , μ n , G n , ρ ) and the natural frequencies. Then, using the cuckoo search algorithm, the transversely isotropic virtual material parameters are determined. Subsequently, as an application case, the flat and V-guide joints of the M7120D/H surface grinder are employed to validate the proposed modeling method. Finally, compared to the experimental modal test results, the error of natural frequencies is less than 1%, which achieves high accuracy. Additionally, the quantitative comparison based on the same application case shows that the proposed modeling method is superior to isotropic virtual material and spring damping method

    The Indirect Impact of Surface Vegetation Improvement on the Climate Response of Sand-Dust Events in Northern China

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    Extensive ecosystem restoration is increasingly seen as an essential practice to mitigate climate change and protect the ecological environment. However, the indirect impact of surface vegetation improvement on the regional climate, such as the climate effect of sand-dust events reduction, has never been evaluated. Here, we estimated the feedback of temperature and precipitation on the change of sand-dust events, arising from the vegetation growth with ecological restoration, using a simple theoretical framework with a series of scenario simulations based on a regional climate model (RegCM). The results showed that revegetation reduced dust emissions, with a contribution rate of approximately 40.15%. With the combined influence of ecological restoration and climate change, the cooling effect of sand-dust events strengthened with the increase in the intensity of sand-dust events, which is mainly caused by the strong absorption of shortwave radiation by the atmosphere. The response of precipitation was uncertain because of tropospheric circulation feedback and shortwave radiation absorption. Our results also indicate that changes in sand-dust events caused by vegetation restoration play important roles in shaping the future climate near the arid and semi-arid regions of northern China. The climatic effects of sand-dust events should be included in assessing ecological restoration impacts to promote sustainable development and enhance our understanding of climate change

    Lattice distortion mechanism study of TiO2 nanoparticles during photocatalysis degradation and reactivation

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    In this paper, the photocatalytic process of TiO2 (P25) is directly characterized by using a positron annihilation lifetime spectroscopy (PALS), high-resolution transmission electron microscopy (HRTEM), Photoluminescence spectroscopy (PL) and UV Raman spectroscopy (Raman). The experimental results reveal that: 1) From PALS measurements, because τ1 and τ2 values and their intensity (I1 and I2) assigned to the different size and amounts of defects, respectively, their variations indicate the formation of different types and amounts of defects during the absorption and degradation. 2) HRTEM observations show that the lattice images become partly blurring when the methylene blue is fully degradated, and clear again after exposed in the air for 30 days. According to the results, we propose a mechanism that the lattice distortion induces the defects as electron capture sites and provides energy for improving photocatalytic process. Meanwhile, the lattice distortion relaxation after exposing in the air for 30 days perfectly explains the gradual deactivation of TiO2, because the smaller vacancy defects grow and agglomerate through the several photocatalytic processes. The instrumental PL and Raman are also used to analyze the samples and approved the results of PALS and HRTEM

    Elucidation of the Intestinal Absorption Mechanism of Loganin in the Human Intestinal Caco-2 Cell Model

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    Loganin, iridoid glycosides, is the main bioactive ingredients in the plant Strychnos nux-vomica L. and demonstrates various pharmacological effects, though poor oral bioavailability in rats. In this study, the intestinal absorption mechanism of loganin was investigated using the human intestinal Caco-2 cell monolayer model in both the apical-to-basolateral (A-B) and the basolateral-to-apical (B-A) direction; additionally, transport characteristics were systematically investigated at different concentrations, pHs, temperatures, and potential transporters. The absorption permeability (PappAB) of loganin, which ranged from 12.17 to 14.78 × 10−6cm/s, was high at four tested concentrations (5, 20, 40, and 80μM), while the major permeation mechanism of loganin was found to be passive diffusion with active efflux mediated by multidrug resistance-associated protein (MRP) and breast cancer resistance protein (BCRP). In addition, it was found that loganin was not the substrate of efflux transporter P-glycoprotein (P-gp) since the selective inhibitor (verapamil) of the efflux transporter exhibited little effects on the transport of loganin in the human intestinal Caco-2 cells. Meanwhile, transport from the apical to the basolateral side increased 2.09-fold after addition of a MRP inhibitor and 2.32-fold after addition of a BCRP inhibitor. In summary, our results clearly demonstrate, for the first time, a good permeability of loganin in the human intestinal Caco-2 cell model and elucidate, in detail, the intestinal absorption mechanism and the effects of transporters on iridoid glycosides compounds

    A Multiplex Fragment-Ion-Based Method for Accurate Proteome Quantification

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    Multiplex proteome quantification with high accuracy is urgently required to achieve a comprehensive understanding of dynamic cellular and physiological processes. Among the existing quantification strategies, fragment-ion based methods can provide highly accurate results, but the multiplex capacity is limited to 3-plex. Herein, we developed a multiplex pseudo-isobaric dimethyl labeling (m-pIDL) method to extend the capacity of the fragment-ion-based method to 6-plex by one-step dimethyl labeling with several millidalton and dalton mass differences between precursor ions and enlarging the isolation window of precursor ions to 10 m/z during data acquisition. m-pIDL showed high quantification accuracy within the 20-fold dynamic range. Notably, the ratio compression was 1.13-fold in a benchmark two-proteome model (5:1 mixed E. coli proteins with HeLa proteins as interference), indicating that by m-pIDL, the ratio distortion of isobaric labeling approaches and the approximate 40% ratio shift of the label free quantification strategy could be effectively eliminated. Additionally, m-pIDL did not show ratio variation among post translational modifications (CV = 6.66%), which could benefit the measurement of universal protein properties for proteomic atlases. We further employed m-pIDL to monitor the time-resolved responses of the TGF-beta-induced epithelial-mesenchymal transition (EMT) in lung adenocarcinoma A549 cell lines, which facilitated the finding of new potential regulatory proteins. Therefore, the 6-plex quantification of m-pIDL with the remarkably high accuracy might create new prospects for comprehensive proteome analysis
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