Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
3,575
result(s) for
"Bao, Qi"
Sort by:
Effectiveness of price limits: Evidence from China’s ChiNext market
Starting from August 24, 2020, the daily stock price limits in China’s ChiNext market have been adjusted from 10% to 20%. We use this reform to study the effectiveness of price limits in China’s stock market. We test four hypotheses about price limits: delayed price discovery, volatility spillover, trading interference, and magnet effect. Using the event study method, we examine the differences in the behavior of stock price, trading volume, and volatility before and after the reform. We confirm the delayed price discovery, volatility spillover and trading interference hypothesis of price limits, and find that these negative effects of price limits are more serious when lower limits are hit. In addition, we examine the distribution of large price movements before and after the reform and find no evidence of the magnet effect of price limits. The present research has important implications for policymakers and investors in China’s stock market.
Journal Article
Fecal microbiota transplantation protects rotenone-induced Parkinson’s disease mice via suppressing inflammation mediated by the lipopolysaccharide-TLR4 signaling pathway through the microbiota-gut-brain axis
Background
Parkinson’s disease (PD) is a prevalent neurodegenerative disorder, displaying not only well-known motor deficits but also gastrointestinal dysfunctions. Consistently, it has been increasingly evident that gut microbiota affects the communication between the gut and the brain in PD pathogenesis, known as the microbiota-gut-brain axis. As an approach to re-establishing a normal microbiota community, fecal microbiota transplantation (FMT) has exerted beneficial effects on PD in recent studies. Here, in this study, we established a chronic rotenone-induced PD mouse model to evaluate the protective effects of FMT treatment on PD and to explore the underlying mechanisms, which also proves the involvement of gut microbiota dysbiosis in PD pathogenesis via the microbiota-gut-brain axis.
Results
We demonstrated that gut microbiota dysbiosis induced by rotenone administration caused gastrointestinal function impairment and poor behavioral performances in the PD mice. Moreover, 16S RNA sequencing identified the increase of bacterial genera
Akkermansia
and
Desulfovibrio
in fecal samples of rotenone-induced mice. By contrast, FMT treatment remarkably restored the gut microbial community, thus ameliorating the gastrointestinal dysfunctions and the motor deficits of the PD mice. Further experiments revealed that FMT administration alleviated intestinal inflammation and barrier destruction, thus reducing the levels of systemic inflammation. Subsequently, FMT treatment attenuated blood-brain barrier (BBB) impairment and suppressed neuroinflammation in the substantia nigra (SN), which further decreased the damage of dopaminergic neurons. Additional mechanistic investigation discovered that FMT treatment reduced lipopolysaccharide (LPS) levels in the colon, the serum, and the SN, thereafter suppressing the TLR4/MyD88/NF-κB signaling pathway and its downstream pro-inflammatory products both in the SN and the colon.
Conclusions
Our current study demonstrates that FMT treatment can correct the gut microbiota dysbiosis and ameliorate the rotenone-induced PD mouse model, in which suppression of the inflammation mediated by the LPS-TLR4 signaling pathway both in the gut and the brain possibly plays a significant role. Further, we prove that rotenone-induced microbiota dysbiosis is involved in the genesis of PD via the microbiota-gut-brain axis.
6NusmmVQuAXh_sD82L334K
Video abstract
Journal Article
Multi-grained contrastive-learning driven MLPs for node classification
Node classification tasks are predominantly tackled using Graph Neural Networks (GNNs) due to their ability to capture complex node dependencies through message-passing. However, GNNs suffer from several limitations, including high computational costs, memory inefficiency, and the requirement for complete data including both training and test data to achieve robust generalization. These issues make GNNs less suitable for real-world applications and resource-constrained environments. In this work, we address these challenges by leveraging contrastive learning techniques within Multi-Layer Perceptrons (MLPs) to effectively capture both local and global graph structure information. Our proposed framework incorporates three contrastive learning strategies that enable MLPs to outperform GNNs in terms of classification accuracy, while also providing superior inference speed and lower memory consumption. Extensive experiments on multiple benchmark datasets demonstrate the efficacy of our approach, positioning it as a compelling alternative to traditional GNN-based methods for node classification.
Journal Article
Regulation of M1-type and M2-type macrophage polarization in RAW264.7 cells by Galectin-9
Generally considered as a potent pro-inflammatory signal, β-galactosidelectin suppresses T cell receptor activation, can both promote and inhibit integrin-mediated adhesion and is required in nuclear pre-mRNA splicing. Galectin-9 (Gal-9), a member of β-galactoside lectin, is involved many processes of T cell-mediated diseases (such as autoimmune diseases and asthma) and immunomodulation of macrophages. Macrophages are involved in the occurrence of inflammation, development and digestion and other stages. At different stages of the inflammatory response, macrophages exhibit different phenotypes, but mainly two subtypes, classically (M1) or alternatively (M2) polarization. The purpose of this work is to investigate the effect of overexpression or knockdown of Gal-9 on the macrophage polarization. Macrophage polarization was detected by flow cytometric profiling of secreted cytokines and specific surface markers expression, including nitric oxide synthase 2 (NOS2) and mannose receptor 1 (CD206). Protein and mRNA expression levels of TNF-α, TGF-β, IL-6, IL-10, NF-κB, signal transducer and activator of transcription (Stat)1 and Stat3 were determined by ELISA, western blot analysis or qRT-PCR. Our results implied that differentiation of the mouse macrophage line RAW264.7 into M1-type and M2-type macrophages is followed by marked variations of Gal-9 expression. Furthermore, its overexpression and secretion are tightly associated with M2-type macrophages, whereas its downregulation promotes macrophages to polarize into M1-type macrophages, which confirmed by elevated CD206 and NOS2, respectively. In response to the changes of Gal-9 expression, cytokines, transcription factors and regulators, including TNF-α, IL-6, NF-κB, Stat1, TGF-β, IL-10, and Stat3, were tightly regulated and significantly associated with classically and alternatively activated macrophages. Consistent with characteristics of M1-type macrophages, the transcriptional or translational expression levels or activity of TNF-α, IL-6, Stat1 and NF-κB were markedly increased with knockdown of Gal-9 in macrophages. By contrast, the expression levels or activity of TGF-β, IL-10 and Stat3 were clearly elevated in macrophages with Gal-9 overexpression, which is closely related with M2-type macrophages. Specific expression and secretion patterns of cytokines, transcription factors and regulators in M1-type and M2-type macrophages contribute to better understanding the role of Gal-9 in regulation in macrophages. This study provides a new insight that Gal-9 may be a new immunomodulatory target for macrophages.
Journal Article
Transfer of mitochondria from mesenchymal stem cells derived from induced pluripotent stem cells attenuates hypoxia-ischemia-induced mitochondrial dysfunction in PC12 cells
Mitochondrial dysfunction in neurons has been implicated in hypoxia-ischemia-induced brain injury. Although mesenchymal stem cell therapy has emerged as a novel treatment for this pathology, the mechanisms are not fully understood. To address this issue, we first co-cultured 1.5 × 105 PC12 cells with mesenchymal stem cells that were derived from induced pluripotent stem cells at a ratio of 1:1, and then intervened with cobalt chloride (CoCl2) for 24 hours. Reactive oxygen species in PC12 cells was measured by Mito-sox. Mitochondrial membrane potential (?Ψm) in PC12 cells was determined by JC-1 staining. Apoptosis of PC12 cells was detected by terminal deoxynucleotidal transferase-mediated dUTP nick end-labeling staining. Mitochondrial morphology in PC12 cells was examined by transmission electron microscopy. Transfer of mitochondria from the mesenchymal stem cells derived from induced pluripotent stem cells to damaged PC12 cells was measured by flow cytometry. Mesenchymal stem cells were induced from pluripotent stem cells by lentivirus infection containing green fluorescent protein in mitochondria. Then they were co-cultured with PC12 cells in Transwell chambers and treated with CoCl2 for 24 hours to detect adenosine triphosphate level in PC12 cells. CoCl2-induced PC12 cell damage was dose-dependent. Co-culture with mesenchymal stem cells significantly reduced apoptosis and restored ?Ψm in the injured PC12 cells under CoCl2 challenge. Co-culture with mesenchymal stem cells ameliorated mitochondrial swelling, the disappearance of cristae, and chromatin margination in the injured PC12 cells. After direct co-culture, mitochondrial transfer from the mesenchymal stem cells stem cells to PC12 cells was detected via formed tunneling nanotubes between these two types of cells. The transfer efficiency was greatly enhanced in the presence of CoCl2. More importantly, inhibition of tunneling nanotubes partially abrogated the beneficial effects of mesenchymal stem cells on CoCl2-induced PC12 cell injury. Mesenchymal stem cells reduced CoCl2-induced PC12 cell injury and these effects were in part due to efficacious mitochondrial transfer.
Journal Article
Distribution characteristics and diversity of myxomycetes in three parallel rivers in Yunnan, China
Three Parallel Rivers is one of the world’s biodiversity hotspots. However, the research on myxomycetes diversity is scarce in this area. Random sampling was used to investigate myxomycetes’ diversity and distribution characteristics in this area. One hundred and seventeen species, including three varieties, were obtained, belonging to 28 genera, nine families, and six orders, with
Arcyria cinerea
and
Physarum viride
being the dominant species. Moreover, four species and one variety were first reported in China. Twenty-six species and one variety were first reported in Yunnan Province. The species’ most commonly utilized substrate for fruiting bodies was decaying wood, and
Cribraria
was the dominant genus. The species diversity was most abundant in mixed broadleaf-conifer forests. Species similarity between coniferous and broad-leaved forests was much higher than the pairwise comparison of other forest types. NMDS analysis shows that substrate and forest types had insignificant effects on myxomycetes communities, while river valley had a significant effect. The myxomycetes community similarity between river valleys is unrelated to geographical proximity.
Journal Article
Global burden of thyroid cancer and its attributable risk factors in 204 countries and territories from 1990 to 2019
Background To investigate the burden of thyroid cancer and its attributable risk factors in 204 countries and territories during 30 years. Methods We extracted data from the Global Burden of Disease (GBD) 2019 database, including incidence, mortality, disability‐adjusted life‐years (DALYs), and the attributable risk factors of thyroid cancer from 1990 to 2019. Estimated annual percentage changes (EAPC) were calculated to assess the changes in age‐standardized incidence rate (ASIR), age‐standardized mortality rate (ASMR), and age‐standardized DALYs rate (ASDR). We also examined the associations between cancer burden and the sociodemographic index (SDI). Results The global new cases, death, and DALYs of thyroid cancer in 2019 were 233 847 (95% UI: 211 637–252 807), 45 576 (95% UI: 41 290‐48 775), and 1 231 841 (95% UI: 1 113 585–1 327 064), respectively. From 1990 to 2019, the ASIR of thyroid cancer showed an upward trend (EAPC = 1.25), but ASMR (EAPC = −0.15) and ASDR (EAPC = −0.14) decreased. The burden of thyroid cancer varied at regional and national levels, but the association between ASIR and SDI was positive. We found that the burden of thyroid cancer was mainly concentrated in females and that the age of onset tended to be younger. The proportion of DALYs from thyroid cancer attributable to high body‐mass index was higher in high SDI regions, especially in males. Conclusions The global incidence of thyroid cancer has continued to increase in the past three decades. The high body‐mass index as an important risk factor for thyroid cancer deserves greater attention, especially in high SDI regions. The burden of thyroid cancer varies in 204 countries and territories from 1990 to 2019. The global incidence of thyroid cancer (a) has increased significantly, while the mortality (b) and DALYs (c) have decreased in the past three decades.
Journal Article