331 research outputs found

    Aβ Damages Learning and Memory in Alzheimer's Disease Rats with Kidney-Yang Deficiency

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    Previous studies demonstrated that Alzheimer's disease was considered as the consequence produced by deficiency of Kidney essence. However, the mechanism underlying the symptoms also remains elusive. Here we report that spatial learning and memory, escape, and swimming capacities were damaged significantly in Kidney-yang deficiency rats. Indeed, both hippocampal Aβ40 and 42 increases in Kidney-yang deficiency contribute to the learning and memory impairments. Specifically, damage of synaptic plasticity is involved in the learning and memory impairment of Kidney-yang deficiency rats. We determined that the learning and memory damage in Kidney-yang deficiency due to synaptic plasticity impairment and increases of Aβ40 and 42 was not caused via NMDA receptor internalization induced by Aβ increase. β-Adrenergic receptor agonist can rescue the impaired long-term potential (LTP) in Kidney-yang rats. Taken together, our results suggest that spatial learning and memory inhibited in Kidney-yang deficiency might be induced by Aβ increase and the decrease of β2 receptor function in glia

    Germplasm Evaluation of an Eurasia Steppe Native Specie--Sheepgrass (\u3cem\u3eLeymus chinensis\u3c/em\u3e)

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    Sheepgrass (Leymus chinensis (Trin.) Tzvel) is an advantageous perennial native grass in China and other northern Eurasian countries having steppe. As an important forage grass of great value in animal husbandry, sheepgrass is well known for its abundant foliage, high palatability and high nutritive content. Sheepgrass is also valuable in grassland restoration and conservation since it is a perennial grass with a rhizome network to fix the soil and can survive well in stressful environments. Terefore, the collection, evaluation and utilization of sheepgrass are necessary for protecting grassland biodiversity, for establishing artificial pasture, restoring degraded grassland, and the development of forage industry and animal husbandry in Eurasia’s native steppe. Here, we reviewed our previous studies on the collection, evaluation of phenotypic diversity for germplasm resources, distribution and domestication of wild sheepgrass, and application of sheepgrass new varieties

    Tocopherol attenuates the oxidative stress of BMSCs by inhibiting ferroptosis through the PI3k/AKT/mTOR pathway

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    Oxidative stress can induce bone tissue damage and the occurrence of multiple diseases. As a type of traditional medicine, tocopherol has been reported to have a strong antioxidant effect and contributes to osteogenic differentiation. The purpose of this study was to investigate the protective effect of tocopherol on the oxidative stress of rat bone marrow-derived mesenchymal stem cells (BMSCs) and the underlying mechanisms. By establishing an oxidative stress model in vitro, the cell counting kit-8 (CCK-8), reactive oxygen species (ROS) analysis, Western blot (WB), real-time PCR (RT-PCR), alkaline phosphatase (ALP) staining, and Alizarin Red staining (ARS) evaluated the effects of tocopherol on the cell viability, intracellular ROS levels, and osteogenic differentiation in BMSCs. In addition, ferroptosis-related markers were examined via Western blot, RT-PCR, and Mito-FerroGreen. Eventually, the PI3K/AKT/mTOR signaling pathway was explored. We found that tocopherol significantly maintained the cell viability, reduced intracellular ROS levels, upregulated the levels of anti-oxidative genes, promoted the levels of osteogenic-related proteins, and the mRNA of BMSCs stimulated by H2O2. More importantly, tocopherol inhibited ferroptosis and upregulated the phosphorylation levels of PI3K, AKT, and mTOR of BMSCs upon H2O2 stimulation. In summary, tocopherol protected BMSCs from oxidative stress damage via the inhibition of ferroptosis through the PI3K/AKT/mTOR pathway

    Preparation, characterization and targeting of micronized 10-hydroxycamptothecin-loaded folate-conjugated human serum albumin nanoparticles to cancer cells

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    Qingyong Li, Chen Liu, Xiuhua Zhao, Yuangang Zu, Ying Wang, Baoyou Zhang, Dongmei Zhao, Qi Zhao, Lin Su, Yang Gao, Baihe SunKey Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin, Heilongjiang, People's Republic of ChinaBackground: The purpose of this study was to develop a method for targeted delivery of 10-hydroxycamptothecin (HCPT)-loaded nanoparticles (NPs) to cancer cells.Methods: We first used a supercritical antisolvent process to prepare micronized HCPT (nHCPT), and then folate-conjugated human serum albumin (HSA) nHCPT-loaded NPs (FA-HSA-nHCPT-NPs) were prepared using a NP-coated method combined with a desolvation technique. The amount of folate conjugation was 16 µg · mg-1 HSA.Results: The particle size of the spherical nHCPT microparticles obtained was 118.5 ± 6.6 nm. The particle size and zeta potential of the FA-HSA-nHCPT-NPs were 233.9 ± 1.2 nm and -25.23 ± 2.98 mV, respectively. The FA-HSA-nHCPT-NPs exhibited a smooth surface and a distinct spherical shape, and the results of differential scanning calorimetry and X-ray diffraction indicated that the FA-HSA-nHCPT-NPs presented in a nanostructured amorphous state. The FA-HSA-nHCPT-NPs showed sustained-release characteristics for 120 hours in vitro, with a drug-loading content of 7.3% and an encapsulating efficiency of 79.1%.Conclusion: The FA-NPs were effective delivery systems for uptake by SGC7901 cells compared with folate-free NPs. These results suggest that a NP-coated method combined with a desolvation technique is effective for preparing NPs with drugs having poor solubility in water and most organic solvents, using albumin as the wall material. FA-HSA-NPs are a stable delivery system and have the potential for targeted delivery of anticancer drugs.Keywords: nanoparticle-coated, desolvation technique, 10-hydroxycamptothecin, human serum albumin, folate, targeted delivery&nbsp

    Deep learning with multi-scale feature fusion in remote sensing for automatic oceanic eddy detection

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    Oceanic eddies are ubiquitous in global oceans and play a major role in ocean energy transfer and nutrients distribution, thus being significant for understanding ocean current circulation and marine climate change. They are characterized by a combination of high-speed vertical rotations and horizontal movements, leading to irregular three-dimensional spiral structures. While the ability to detect eddies automatically and remotely is crucial to monitoring important spatial-temporal dynamics, existing methods are inaccurate because eddies are highly dynamic and the underlying physical processes are not well understood. Typically, remote sensing is used to detect eddies based on physical parameters, geometrics or other handcrafted features. In this paper, we show how Deep Learning may be used to reliably extract higher-level features and then fuse multi-scale features to identify eddies, regardless of their structures and scales. We learn eddy features using two principal component analysis convolutional layers, then perform a non-linear transformation of the features through a binary hashing layer and block-wise histograms. To handle the difficult problem of spatial variability across synthetic aperture radar (SAR) images, we introduce a spatial pyramid model to allow multi-scale features fusion. Finally, a linear support vector machine classifier recognizes the eddies. Our method, dubbed DeepEddy, is benchmarked against a dataset of 20,000 SAR image samples, achieving a 97.8 ± 1% accuracy of detection

    Germination characteristics among different sheepgrass (Leymus chinensis) germplasm during the seed development and after-ripening stages

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    Sheepgrass (Leymus chinensis (Trin.) Tzvel) is an important forage grass in the Eurasian steppe. However, little information is available concerning its seed morphological features and germination characteristics during seed development and after-ripening among different germplasm. To clarify the appropriate seed harvest time and the effects of germplasm, seed development and after-ripening on seed germination, 20 germplasm of sheepgrass were selected. Moreover, the seed morphological and physical changes as well as the seed germination and dormancy characteristics of sheepgrass during seed development stages were analyzed using a seven—d gradient of day after pollination (DAP). The results indicated that the seed water content decreased significantly during 35–42 DAP and that the highest seed germination rate of most germplasm was observed at 35–42 DAP. Thus, 35–42 DAP may be the best time to harvest sheepgrass to obtain the maximum seed germination rate and avoid seed shattering. Furthermore, our results indicated that there were six types of germination patterns, including germplasm with increasing germination rates in the developing seed, such as S19 and S13, and germplasm that maintained a consistently low germination rate, such as S10. Moreover, we compared the seed germination rate of eight germplasm during seed development in both 2016 and 2017, and the results indicated that the seed germination patterns of the eight germplasm were highly consistent between the two consecutive years, suggesting that germplasm rather than year is the major factor in determining germination during seed development. The effect of after-ripening on seed germination was different among the germplasm where four types of germination patterns were revealed for 10 germplasm and resulted in various dormancy features. A two-factor ANOVA analysis suggested that the germplasm of the sheepgrass has a large influence on seed germination, whether during seed development or after-ripening. Thus, these findings lay the foundation for future studies on seed dormancy and germination and may guide the breeding of new cultivars of sheepgrass with better germination performance

    Spermidine improves the antioxidant capacity and morphology of intestinal tissues and regulates intestinal microorganisms in Sichuan white geese

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    IntroductionIntestinal health is very important to the health of livestock and poultry, and is even a major determining factor in the performance of livestock and poultry production. Spermidine is a type of polyamine that is commonly found in a variety of foods, and can resist oxidative stress, promote cell proliferation and regulate intestinal flora.MethodsIn this study, we explored the effects of spermidine on intestinal health under physiological states or oxidative stress conditions by irrigation with spermidine and intraperitoneal injection of 3-Nitropropionic acid (3-NPA) in Sichuan white goose.Results and discussionOur results showed that spermidine could increase the ratio of intestinal villus to crypt and improve intestinal morphology. In addition, spermidine can also reduce malondialdehyde (MDA) accumulation caused by 3-NPA by increasing superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) enzyme activity, thus alleviating intestinal damage. Furthermore, spermidine can regulate intestinal digestive enzyme activities and affect intestinal digestion and absorption ability. Spermidine can also promote an increase in intestinal microbial diversity and abundance and alleviate the change of microflora structure caused by 3-NPA. In conclusion, spermidine promotes the production of beneficial intestinal metabolites such as Wikstromol, Alpha-bisabolol and AS 1–5, thus improving the level of intestinal health. Taken together, these results indicate that spermidine can improve intestinal health by improving intestinal morphology, increasing antioxidant capacity and regulating intestinal flora structure

    Aberrant Dynamic Functional Network Connectivity and Graph Properties in Major Depressive Disorder

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    Major depressive disorder (MDD) is a complex mood disorder characterized by persistent and overwhelming depression. Previous studies have identified abnormalities in large scale functional brain networks in MDD, yet most of them were based on static functional connectivity. In contrast, here we explored disrupted topological organization of dynamic functional network connectivity (dFNC) in MDD based on graph theory. One hundred and eighty-two MDD patients and 218 healthy controls were included in this study, all Chinese Han people. By applying group information guided independent component analysis (GIG-ICA) to resting-state functional magnetic resonance imaging (fMRI) data, the dFNCs of each subject were estimated using a sliding window method and k-means clustering. Network properties including global efficiency, local efficiency, node strength and harmonic centrality, were calculated for each subject. Five dynamic functional states were identified, three of which demonstrated significant group differences in their percentage of state occurrence. Interestingly, MDD patients spent much more time in a weakly-connected State 2, which includes regions previously associated with self-focused thinking, a representative feature of depression. In addition, the FNCs in MDD were connected differently in different states, especially among prefrontal, sensorimotor, and cerebellum networks. MDD patients exhibited significantly reduced harmonic centrality primarily involving parietal lobule, lingual gyrus and thalamus. Moreover, three dFNCs with disrupted node properties were commonly identified in different states, and also correlated with depressive symptom severity and cognitive performance. This study is the first attempt to investigate the dynamic functional abnormalities in MDD in a Chinese population using a relatively large sample size, which provides new evidence on aberrant time-varying brain activity and its network disruptions in MDD, which might underscore the impaired cognitive functions in this mental disorder

    Methanol electrosynthesis from CO2 at Cu2O/ZnO prompted by pyridine-based aqueous solutions

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    In this study, we examine the electrochemical-driven reduction of CO2 to methanol at Cu2O/ZnO gas diffusion electrodes in soluble pyridine-based electrolytes at different concentrations. The process is evaluated first by cyclic voltammetric analyses and then, for the continuous reduction of CO2 in a filter-press electrochemical cell. The results showed that the use of pyridine-based soluble co-catalysts lowered the overpotential for the electrochemical reduction of CO2, enhancing also reaction performance (i.e. reaction rate and Faradaic efficiency). Reaction outcome is discussed on the basis of the role that N-ligands play on the mechanism and the inductive effect caused by the electron-releasing or electron-withdrawing substituents of the aromatic ring. In particular, the maximum methanol formation rate and Faradaic efficiency reached at the 2-methylpyridine (with electron-releasing substituents)-based system with a pH of 7.6 and an applied current density of j = 1 mA cm−2 were r = 2.91 μmol m−2 s−1 and FE = 16.86%, respectively. These values significantly enhance those obtained in the absence of any molecular catalyst (r = 0.21 μmol m−2 s−1 and FE = 1.2%). The performance was further enhanced when lowering the electrolyte pH by adding HCl (r = 4.42 μmol m−2 s−1 and FE = 25.6% at pH = 5), although the system showed deactivation in the long run (5 h) which appears largely to be due to a change in product selectivity of the reaction (i.e. formation of ethylene).The authors gratefully acknowledge the financial support from the Spanish Ministry of Economy and Competitiveness (MINECO), under the projects CTQ2013-48280-C3-1-R, CTQ2014-55716-REDT and Juan de la Cierva program (JCI-2012-12073)

    PANDORA-seq expands the repertoire of regulatory small RNAs by overcoming RNA modifications

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    Although high-throughput RNA sequencing (RNA-seq) has greatly advanced small non-coding RNA (sncRNA) discovery, the currently widely used complementary DNA library construction protocol generates biased sequencing results. This is partially due to RNA modifications that interfere with adapter ligation and reverse transcription processes, which prevent the detection of sncRNAs bearing these modifications. Here, we present PANDORA-seq (panoramic RNA display by overcoming RNA modification aborted sequencing), employing a combinatorial enzymatic treatment to remove key RNA modifications that block adapter ligation and reverse transcription. PANDORA-seq identified abundant modified sncRNAs—mostly transfer RNA-derived small RNAs (tsRNAs) and ribosomal RNA-derived small RNAs (rsRNAs)—that were previously undetected, exhibiting tissue-specific expression across mouse brain, liver, spleen and sperm, as well as cell-specific expression across embryonic stem cells (ESCs) and HeLa cells. Using PANDORA-seq, we revealed unprecedented landscapes of microRNA, tsRNA and rsRNA dynamics during the generation of induced pluripotent stem cells. Importantly, tsRNAs and rsRNAs that are downregulated during somatic cell reprogramming impact cellular translation in ESCs, suggesting a role in lineage differentiation
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