39 research outputs found

    Scholars' data reuse behaviors in disciplinary context: A meta-synthesis study

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    Data reuse plays a pivotal role in science research in the data era. Given that the impact of discipline culture on data reuse is deeply rooted, we explore data reuse behaviors of the two groups of scholars with significantly different qualities, the nature science and the humanities and social science. Relying on the meta-synthesis and inductive coding approach, information about intentions, influence factors, data processing and using and data reuse barriers were extracted from 37 qualified articles and then analyzed. Results show: 1) informal channels perform a vital role in data reuse in both two communities; 2) there is a distinct correlation between data reuse and disciplinary context. 3) clear distinctions exist between two fields in data reuse barriers, disciplinary practice degrees and data reuse patterns. The results imply the urgency to establish data managers, link publications and data, and enhance data organization

    The Controversy, Challenges, and Potential Benefits of Putative Female Germline Stem Cells Research in Mammals

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    The conventional view is that female mammals lose their ability to generate new germ cells after birth. However, in recent years, researchers have successfully isolated and cultured a type of germ cell from postnatal ovaries in a variety of mammalian species that have the abilities of self-proliferation and differentiation into oocytes, and this finding indicates that putative germline stem cells maybe exist in the postnatal mammalian ovaries. Herein, we review the research history and discovery of putative female germline stem cells, the concept that putative germline stem cells exist in the postnatal mammalian ovary, and the research progress, challenge, and application of putative germline stem cells in recent years

    SIRT5 promotes IDH2 desuccinylation and G6PD deglutarylation to enhance cellular antioxidant defense

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    Abstract Excess in mitochondrial reactive oxygen species (ROS) is considered as a major cause of cellular oxidative stress. NADPH, the main intracellular reductant, has a key role in keeping glutathione in its reduced form GSH, which scavenges ROS and thus protects the cell from oxidative damage. Here, we report that SIRT5 desuccinylates and deglutarylates isocitrate dehydrogenase 2 (IDH2) and glucose‐6‐phosphate dehydrogenase (G6PD), respectively, and thus activates both NADPH‐producing enzymes. Moreover, we show that knockdown or knockout of SIRT5 leads to high levels of cellular ROS. SIRT5 inactivation leads to the inhibition of IDH2 and G6PD, thereby decreasing NADPH production, lowering GSH, impairing the ability to scavenge ROS, and increasing cellular susceptibility to oxidative stress. Our study uncovers a SIRT5‐dependent mechanism that regulates cellular NADPH homeostasis and redox potential by promoting IDH2 desuccinylation and G6PD deglutarylation

    SIRT3-dependent GOT2 acetylation status affects the malate-aspartate NADH shuttle activity and pancreatic tumor growth

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    The malate–aspartate shuttle is indispensable for the net transfer of cytosolic NADH into mitochondria to maintain a high rate of glycolysis and to support rapid tumor cell growth. The malate–aspartate shuttle is operated by two pairs of enzymes that localize to the mitochondria and cytoplasm, glutamate oxaloacetate transaminases (GOT), and malate dehydrogenases (MDH). Here, we show that mitochondrial GOT2 is acetylated and that deacetylation depends on mitochondrial SIRT3. We have identified that acetylation occurs at three lysine residues, K159, K185, and K404 (3K), and enhances the association between GOT2 and MDH2. The GOT2 acetylation at these three residues promotes the net transfer of cytosolic NADH into mitochondria and changes the mitochondrial NADH/NAD+ redox state to support ATP production. Additionally, GOT2 3K acetylation stimulates NADPH production to suppress ROS and to protect cells from oxidative damage. Moreover, GOT2 3K acetylation promotes pancreatic cell proliferation and tumor growth in vivo. Finally, we show that GOT2 K159 acetylation is increased in human pancreatic tumors, which correlates with reduced SIRT3 expression. Our study uncovers a previously unknown mechanism by which GOT2 acetylation stimulates the malate–aspartate NADH shuttle activity and oxidative protection

    Neurotoxicity of Benzotriazole Ultraviolet Stabilizers in Teleost Fishes: A Review

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    Plastic additives that maintain integrity have been extensively studied for potential toxicity to fish; however, chemicals that protect polymers from (artificial) UV degradation are less studied. Benzotriazole UV stabilizers (BUVSs) are the most widely used UV stabilizers in plastics and are often used in sunscreens, cosmetics, paint, and food packaging. BUVSs can negatively affect aquatic wildlife when released into the environment via plastic degradation. In this review, we summarize the distribution of BUVSs globally and discuss neurotoxicological endpoints measured in fish to understand how these plastic additives can affect the neurological health of teleost fishes. BUVSs have been detected in aquatic environments at concentrations ranging from 0.05 up to 99,200 ng/L. Studies show that BUVSs affect behavioral responses and acetylcholinesterase activity, indicators of neurotoxicity. Our computational analysis using transcriptome data suggests certain pathways associated with neurodegeneration are responsive to exposure to BUVSs, like “Complement Activation in Alzheimer’s Disease”. Based on our review, we identify some research needs for future investigations: (1) molecular studies in the central nervous system to define precise mechanisms of neurotoxicity; (2) a wider range of tests for assessing aberrant behaviors given that BUVSs can affect the activity of larval zebrafish; and (3) histopathology of the nervous system to accompany biochemical analyses. These data are expected to enhance understanding of the neurotoxicity potential of benzotriazoles and other plastic additives

    The complete chloroplast genome of Euphorbia ebracteolata Hayata (Euphorbiaceae)

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    Euphorbia ebracteolata is a perennial medicinal plant and widely used in China for thousands of years. The complete chloroplast genome reported here is 163,090 bp in length, including two inverted repeats (IRs) of 26,699 bp, which are separated by a large single-copy (LSC) and a small single-copy (SSC) of 91,943 and 17,749 bp, respectively. The whole chloroplast genome of E. ebracteolata contains 112 genes, including 78 protein-coding genes, 30 transfer RNA, and 4 ribosome RNA. Phylogenetic analysis result strongly indicated that E. ebracteolata is closely related to E. helioscopia

    Novel Design Scheme for Structural Fundamental Frequency of Porous Acoustic Metamaterials

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    Structural resonance increases the vibration and noise of porous acoustic metamaterials while reducing the energy consumption and conversion efficiency of acoustic waves. Therefore, structural fundamental frequency of porous acoustic metamaterials is required to be controlled to avoid resonance. This study proposes a full-cycle interactive progressive (FIP) design scheme for porous acoustic metamaterials. The FIP design scheme first establishes a specific parameter relationship for the initial model based on the intentions of the designers. The initial model is then dynamically adjusted through a series of optimization processes. In particular, the FIP design scheme is developed for a porous acoustic metamaterial in an acoustic-structure interaction system. The effects of the structural parameters and applied boundary conditions of the porous acoustic metamaterial on the structural fundamental frequency are investigated. A surrogate model is introduced to reduce the calculation costs and improve the design efficiency of the parametric optimization. The frequency-modulation acoustic metamaterial is tailored to improve its acoustic and vibrational characteristics, including the resonance resistance and low dynamic response. The features of the FIP design scheme in the optimized design of porous acoustic metamaterials are demonstrated

    Extraordinary Characteristics of One-Dimensional PT-Symmetric Ring Optical Waveguide Networks Composed of Adjustable Length Ratio Waveguides

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    A novel one-dimensional parity-time-symmetric periodic ring optical waveguide network (1D PTSPROWN) is constructed using magnesium fluoride (MgF2), by adjusting the length ratio of gain and loss materials in PT-symmetric waveguide and ordinary dielectric material, and by optimizing the program to search for the extremum spontaneous PT-symmetric breaking points. The ultra-strong transmission, reflection, and photonic location are noticed in the proposed 1DPTSPROWN as compared with the other PT-symmetric optical waveguide networks. The maximum and minimum reached 1018 and 10−15, respectively, which is more than 6 orders of magnitude greater and 3 orders of magnitude smaller than the best results reported so far. The ultra-strong transmission and reflection peaks, ultra-weak transmission, and reflection valleys generated by electromagnetic waves in this network were found to have interesting resonance and anti-resonance effects. Furthermore, frequency of periodic cycles and violet or redshift laws were discovered in the 1D PTSPROWN of fixed length ratio of gain and loss material in the PT-symmetric waveguide by adjusting the ratio of the upper and lower arm lengths of waveguides. The proposed optical waveguide network might have potential application in the design of CPA lasers, high-efficiency optical accumulators, and several other devices

    The Expression of Markers Related to Ovarian Germline Stem Cells in the Mouse Ovarian Surface Epithelium and the Correlation with Notch Signaling Pathway

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    Background/Aims: Ovarian germline stem cells (OGSCs) have been shown to mainly exist in the ovarian surface epithelium (OSE), but the activity changes of germline stem cells during different reproductive stages and the potential regulatory signaling pathway are still unknown. The Notch signaling pathway plays a key role in cell development, primordial follicles and stem cell proliferation. However, whether it plays a role in the proliferation of OGSCs is unknown. Here, we analyzed the activity changes of germline stem cells and the correlation between germline stem cells and the Notch signaling pathway. Methods: The expression of germline stem cell markers Mvh, Ooc4 and the Notch molecules Notch1, Hes1, and Hes5 were detected during 3 days (3d), and 2, 12, 20 months (2m, 12m, 20m) mouse ovarian surface epithelium samples. DAPT, a specific inhibitor of the Notch pathway, was used to observe the influence of Notch signaling in the germline stem cells. Results: The results showed that the levels of MVH and OCT4 decreased substantially with reproductive age in ovarian surface epithelium, and the same tendency was detected in the Notch signaling molecules Notch1, Hes1 and Hes5. Dual-IF results showed that the germline stem cell markers were co-expressed with Notch molecules in the ovarian surface epithelium. While, the expression of MVH and OCT4 were reduced when the ovaries were treated with DAPT and the levels were attenuated with increasing dose of DAPT. Conclusion: Taken together, our results indicate that the viability of OGSCs decreased with the age of the mouse ovaries, and the activity of OGSCs in the ovarian surface epithelium may be related to the Notch signaling pathway
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