SDSS-IV MaNGA: properties of galaxies with kinematically decoupled stellar and gaseous components

We study the properties of 66 galaxies with kinematically misaligned gas and stars from MaNGA survey. The fraction of kinematically misaligned galaxies varies with galaxy physical parameters, i.e. M*, SFR and sSFR. According to their sSFR, we further classify these 66 galaxies into three categories, 10 star-forming, 26 ‘Green Valley’ and 30 quiescent ones. The properties of different types of kinematically misaligned galaxies are different in that the star-forming ones have positive gradient in Dn4000 and higher gas-phase metallicity, while the green valley/quiescent ones have negative Dn4000 gradients and lower gas-phase metallicity on average. There is evidence that all types of the kinematically misaligned galaxies tend to live in more isolated environment. Based on all these observational results, we propose a scenario for the formation of star-forming galaxies with kinematically misaligned gas and stars \-− the progenitor accretes misaligned gas from a gas-rich dwarf or cosmic web, the cancellation of angular momentum from gas–gas collisions between the pre-existing gas and the accreted gas largely accelerates gas inflow, leading to fast centrally concentrated star formation. The higher metallicity is due to enrichment from this star formation. For the kinematically misaligned green valley and quiescent galaxies, they might be formed through gas-poor progenitors accreting kinematically misaligned gas from satellites which are smaller in mass

SDSS-IV MaNGA: A Serendipitous Observation of a Potential Gas Accretion Event

The nature of warm, ionized gas outside of galaxies may illuminate several key galaxy evolutionary processes. A serendipitous observation by the MaNGA survey has revealed a large, asymmetric Hα complex with no optical counterpart that extends ≈8\u27\u27 (≈6.3 kpc) beyond the effective radius of a dusty, starbursting galaxy. This Hα extension is approximately three times the effective radius of the host galaxy and displays a tail-like morphology. We analyze its gas-phase metallicities, gaseous kinematics, and emission-line ratios and discuss whether this Hα extension could be diffuse ionized gas, a gas accretion event, or something else. We find that this warm, ionized gas structure is most consistent with gas accretion through recycled wind material, which could be an important process that regulates the low-mass end of the galaxy stellar mass function

Study on the protective effects and mechanisms of DMDD isolated from Averrhoa carambola L. root on differentiated SH-SY5Y cell damage induced by α-Synuclein PFFs

Objective To explore the protective effects and mechanisms of different concentrations of Averrhoa carambola L. root extract 2-Dodecyl-6-Methoxycyclohexa-2, 5-Diene-1, 4-Dione (DMDD) on α -Syn PFFs-induced differentiated SH-SY5Y cell damage. Methods The SH-SY5Y cells differentiated by retinoic acid were treated with different concentrations of DMDD, followed by detecting the cell viability by MTS to determine the low, medium, and high concentrations of DMDD for use in these cells. The cells were treated with various concentrations of DMDD in an established model of cell damage induced by 5 μg/mL α-Syn PFF. Hoechst 33342 staining and nitric oxide kit were used to detect the number of cells with nuclear damage and intracellular nitric oxide production, respectively. The protein expression levels of tyrosine hydroxylase (TH), polyadenylate diphosphate (PAR) and polyadenylate diphosphate ribozyme-1 (PARP-1) were measured by western blotting. Immunofluorescence was used to detect the number of cells positive for phosphorylated serine 129 α-synuclein (pS129-α-Syn), phosphorylated histone H2AX (γH2AX), and nuclear translocation of apoptosis-inducing factor (AIF). Results Hoechst 33342 staining demonstrated that the number of cells with nuclear damage was significantly decreased in all DMDD treatment groups compared with the α-Syn PFFs model group (P < 0.001). The nitric oxide assay results showed that nitric oxide production was significantly reduced in the DMDD treatment groups compared with the α-Syn PFFs model group (P < 0.01 or P < 0.001). Western blotting revealed that compared with the α-Syn PFFs model group, TH protein expression level was significantly increased in the high DMDD concentration treatment group (P < 0.05), while PAR protein expression levels were significantly decreased in the medium and high DMDD concentration treatment groups (P < 0.05), and the protein expression levels of PARP-1 and Cleaved PARP-1 were significantly decreased in the high DMDD concentration treatment group (P < 0.05). Immunofluorescence results showed that compared with the α-Syn PFFs model group, the number of pS129-α-Synpositive cells was decreased significantly after treatment with medium and high concentrations of DMDD (P < 0.05 or P < 0.01), while the number of γH2AX-positive cells and AIF nuclear translocation cells was decreased significantly in all DMDD treatment groups (P < 0.01 or P < 0.001). Conclusion DMDD may attenuate the damage in differentiated SH-SY5Y cells induced by α-Syn PFFs through inhibition of PARP-1-dependent cell death mediated by the PARP-1/AIF pathway

Progress and challenges in the application of vacuum assisted venous drainage in cardiac surgery

Vacuum assisted venous drainage (VAVD) is a technique that increases the volume of venous drainage by applying negative pressure in a closed blood reservoir. In cardiac surgery, especially in minimally invasive cardiac surgery and low-weight patients, VAVD technology has been widely used because of its significant advantages of improving venous drainage efficiency, reducing cardiopulmonary bypass (CPB) priming and improving the clarity of the surgical field. This article reviews the basic principles of VAVD technology, its clinical application in cardiac surgery, and its technical advantages, including improving surgical safety and reducing intraoperative complications. In addition, the challenges faced in the practical application of VAVD technology, such as gas embolism risk, blood injury, device complexity, and high operational requirements, are discussed. In order to solve these problems, this article proposes improvement measures and future research directions, so as to further optimize the application of VAVD technology, improve its reliability and safety in cardiac surgery, and promote the widespread application and continuous improvement of VAVD technology in cardiac surgery

Forecasting China’s CO2 Emissions for Energy Consumption Based on Cointegration Approach

Forecasting CO2 emissions is important for climate policy decision making. The paper attempts to implement empirically the long-term forecast of CO2 emissions based on cointegration theory under the business-as-usual scenario, by using statistical data from China over the period 1953 to 2016. We focus on the relationships between CO2 emissions for energy consumption and influential factors: per capita GDP, urbanization level, energy intensity, and total energy consumption. The empirical results are presented as follows: (1) continuous increase of carbon pollution resulting from energy consumption (1953-2016) indicates that China has beard great pressure of carbon reduction. (2) Though reduction of carbon intensity in 2020 would account for 50.14% that of 2005, which meets the requirements announced by Chinese government in 2009, China would bear carbon emissions for energy consumption of 14.4853 billion tCO2 by 2030, which is nearly 1.59 times that of 2016 and nearly 105 times that of 1953. The results suggest that the policymakers in China may take more effective measures such as reducing energy intensities and formulating stricter environmental regulations in order to mitigate the CO2 emissions and realize the win-win of economic and ecological benefits

Taxonomic studies on the genus Hydrocotyle (Apiales) from China: The distribution and morphology of H. chiangdaoensis, with H. calcicola reduced to a synonym

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