197 research outputs found
INFLUENCE OF RARE-EARTH DOPING ON THE ELECTRICAL PROPERTIES OF HIGH VOLTAGE GRADIENT ZnO VARISTORS
The influence of rare-earth doping on the electrical properties of ZnO varistors was investigated. In a lower doping region, the electrical properties were greatly improved with the increase of rare-earth contents. The highest voltage gradient value of 1968.0 V/mm was obtained with a rare-earth concentration of 0.06 mol. %. The microstructure of samples with different amounts of rare-earth oxides was examined and the notable decrease of grain size was identified as the origin for the increased voltage gradient. The doped rare-earth oxides dissolved at the grain boundaries and the excessive doping reduced the voltage across the single grain/grain boundary from 2.72 V to 0.91 V. The poor electrical properties in a higher doping region resulted from the degeneration of grain boundaries and the decrease of block density
Inhibition of miR-665 alleviates lipopolysaccharide-induced inflammation via up-regulation of SOCS7 in chondrogenic ATDC5 cells
Purpose: To examine the effect and mechanism of action of miR-665 in osteoarthritis.Methods: An in vitro inflammatory injury model of osteoarthritis was established using chondrogenic ATDC5 cells with lipopolysaccharide (LPS) treatment. The expression levels of inflammatory cytokines were determined by enzyme-linked immunosorbent assays (ELISAs) and by quantitative real-time polymerase chain reaction (qRT-PCR). A binding target for miR-665 was predicted using TargetScan and then evaluated using a dual-luciferase reporter assay.Results: Treatment with LPS significantly up-regulated the inflammatory cytokine expressions of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-alpha (TNF-α), in ATDC5 cells (p < 0.01), and the expression of miRNA-665 was significantly increased in LPS-treated ATDC5 cells (p < 0.01).Knockdown of miR-665 down-regulated the expression levels of these inflammatory cytokines. Suppressor of cytokine signaling 7 (SOCS7) was identified as a target of miR-665. Data from qRT-PCR and western-blot analyses indicated that SOCS7 expression was promoted by miR-665 inhibition and inhibited by miR-665 over-expression. LPS treatment significantly decreased the expression of SOCS7 protein in ATDC5 cells (p < 0.01), and over-expression of SOCS7 attenuated the LPS-stimulated inflammatory injury. In addition, over-expression of miR-655 enhanced the inflammatory injury and reversed the protective effect of SOCS7 against LPS-stimulated inflammation.Conclusion: Inhibition of miR-665 alleviated LPS-stimulated inflammatory injury in ATDC5 cells via the up-regulation of SOCS7, suggesting a potential therapeutic target for osteoarthritis.
Keywords: MiR-665, Lipopolysaccharide, Inflammation, SOCS7, Chondrogenic, ATDC
Network resilience
Many systems on our planet are known to shift abruptly and irreversibly from
one state to another when they are forced across a "tipping point," such as
mass extinctions in ecological networks, cascading failures in infrastructure
systems, and social convention changes in human and animal networks. Such a
regime shift demonstrates a system's resilience that characterizes the ability
of a system to adjust its activity to retain its basic functionality in the
face of internal disturbances or external environmental changes. In the past 50
years, attention was almost exclusively given to low dimensional systems and
calibration of their resilience functions and indicators of early warning
signals without considerations for the interactions between the components.
Only in recent years, taking advantages of the network theory and lavish real
data sets, network scientists have directed their interest to the real-world
complex networked multidimensional systems and their resilience function and
early warning indicators. This report is devoted to a comprehensive review of
resilience function and regime shift of complex systems in different domains,
such as ecology, biology, social systems and infrastructure. We cover the
related research about empirical observations, experimental studies,
mathematical modeling, and theoretical analysis. We also discuss some ambiguous
definitions, such as robustness, resilience, and stability.Comment: Review chapter
3-O-Caffeoylquinic acid in Periploca forrestii Schltr extract ameliorates collagen-induced arthritis by inducing IL17/IL23 cells in rats
Purpose: To study the therapeutic effect of 3-O-caffeoylquinic acid (3-O-CQA) from Periploca forrestii extract (PFE) on collagen-mediated arthritis (CIA) in rats, as well as the potential underlying mechanism of action.
Methods: PFE and 3-O-CQA were successively and intragastrically administered to CIA rats. Paw swelling, arthritic scores and H & E staining were used to evaluate the therapeutic effect of 3-O-CQA. Moreover, to determine the effects of PFE and 3-O-CQA on fibroblast-resembling synoviocytes obtained from arthritic subjects (RAFLS), the viability of RAFLS cultured in vitro was measured with MMT, while apoptotic lesions were analyzed by flow cytometry. The levels of IL-6 in CIA and RAFLS were determined by enzyme-linked immunosorbent assay (ELISA), while quantitative reverse transcriptionpolymerase chain reaction (qRT-PCR) and immunoblotting were used to assess their mRNA and
polypeptide levels, respectively.
Results: PFE in 3-O-CQA ameliorated swelling and reduced arthritic scores in CIA rat model, and also decreased cytokine levels (p < 0.05). By decreasing mRNA and protein expressions, 3-O-CQA repressed the phosphorylation of STAT3 and JAK2 as well as the protein levels of IL-23 and RORγt (p < 0.05).
Conclusion: The results of this study show that CIA and RAFLS are ameliorated in rats by 3-O-CQA in PFE through regulation of IL17/ IL23 and Th17 cells. Thus, 3-O-CQA affords a therapeutic strategy for the management of collagen-induced arthritis.
Keywords: Arthriti; Periploca forrestii Schltr extract; 3-O-Caffeoylquinic acid; Interleukin (IL)-17; IL-23; Th17 cell
Effect of Miao medicine, Jinwujiangu decoction, on IL- 17/IL-23 inflammatory axis of fibroblast-like synoviocytes in rheumatoid arthritis
Purpose: To explore the influence of the Miao medicine, Jinwujiangu decoction, on the interleukin (IL)- 17/IL-23 inflammatory axis of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA).Methods: Synovial tissue samples were randomly divided into a blank control group, high-dose (0.06mg/mL), medium-dose (0.6mg/mL), and low-dose (6.0mg/mL) groups of Jinwujiangu decoction, a leflunomide group, and a tripterygium glycosides group. Proliferation of RA synovial cells was detected by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Enzyme-linked immunosorbent assay (ELISA) was used to determine the secretion of IL-6, transforming growth factor beta (TGF-β), and IL-17. Real-time polymerase chain reaction was used to evaluate the expression of IL-23R, IL-17R, RAR-related orphan receptor alpha (RORα), RORγt, and signal transducer and activator of transcription (STAT3) mRNA. The protein activities of IL-17R, STAT3 and pSTAT3 were assessed by Western blot assay.Results: Jinwujiangu decoction inhibited the proliferation of RA synovial cells. Treatment with different drug concentrations resulted in downregulation of IL-6, TGF-β, and IL-17 secretion. The expression levels of IL-23R, IL-17R, RORα, RORγt, and STAT3 mRNA in RA-FLS were significantly reduced after intervention with different drugs. Protein expression levels of STAT3, pSTAT3, and IL-17 in the different drug treatment groups were significantly decreased.Conclusion: Jinwujiangu decoction inhibits the secretion of IL-6 and TGF-β in RA-FLS, and intervenes to regulate gene expression of IL-23/IL-17 inflammation axis and suppress immune inflammation. The results of this study provide new evidence for the study of anti-inflammatory mechanism of TCM compound prescription.Keywords: Jinwujiangu decoction, IL-17/IL-23, Fibroblast-like synoviocytes, Rheumatoid arthritis, Ethnomedicin
Effectiveness of Yijinjing on cognitive and motor functions in patients with Parkinson’s disease: study protocol for a randomized controlled trial
BackgroundParkinson’s disease (PD) is a common neurodegenerative disorder that affects motor and non-motor functions, significantly reducing patients’ quality of life. No effective drug-based treatments are known to solve this problem. Non-drug therapies such as Yijinjing exercise have shown potential in improving cognitive and motor functions in PD patients. However, solid evidence must still be provided to support their clinical efficacy. This study aims to evaluate the clinical efficacy of Yijinjing exercise interventions in PD patients and explore the underlying mechanisms between the cognitive and motor functions in PD.MethodsThis is a single-center randomized controlled trial in which 96 eligible PD patients will be randomly assigned to receive either Yijinjing exercise group or brisk walking group or control group in a ratio of 1:1:1. Interventions (Yijinjing exercise or brisk walking training, 40 min per session) will be provided in 3 sessions per week (Monday, Wednesday, Friday) for 12 weeks, with a total of 36 sessions. After the treatment, there will be a 1-month follow-up period. The primary outcomes will be measured using the Montreal Cognitive Assessment (MoCA) and the Unified Parkinson’s Disease Rating Scale motor section (UPDRS-III). Secondary outcomes include balance function, executive function, walking function, sleep quality, and quality of life. Additionally, the prefrontal cerebral and sensorimotor cortex blood oxygen signal level will be collected to explore the underlying mechanisms. All outcomes will be assessed at baseline, at the end of 12 weeks of treatment and after an additional 1-month follow-up period.DiscussionThe results of the study protocol will provide high-quality evidence for the potential of intervention measures based on the Yijinjing exercise to improve the cognitive and activity levels of Parkinson’s disease patients. We envision the Yijinjing exercise as a non-pharmacological family activity that can provide a new and more effective method for the treatment of Parkinson’s disease patients or those at risk.Clinical trial registrationThis study was approved by the Ethics Committee of the Second Rehabilitation Hospital of Shanghai (2020-05-01). The trial has been registered in the China Clinical Trials Registry (ChiCTR2200055636)
Prediction and Verification of the Major Ingredients and Molecular Targets of Tripterygii Radix Against Rheumatoid Arthritis
Tripterygii Radix exhibits good clinical efficacy and safety in rheumatoid arthritis (RA) patients, but its effective components and mechanism of action are still unclear. The purpose of this study was to explore and verify the major ingredients and molecular targets of Tripterygii Radix in RA using drug-compounds-biotargets-diseases network and protein-protein interaction (PPI) network analyses. The processes and pathways were derived from Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. The most important compounds and biotargets were determined based on the degree values. RA fibroblast-like synoviocytes (RA-FLS) were separated from RA patients and identified by hematoxylin and eosin (HE) staining and immunohistochemistry. The purity of RA-FLS was acquired by flow cytometry marked with CD90 or VCAM-1. RA-FLS were subjected to control, dimethyl sulfoxide (control), kaempferol, or lenalidomide treatment. Cell migration was evaluated by the transwell assay. The relative expression of biotarget proteins and cytokines was analyzed by western blotting and flow cytometry. In total, 144 chemical components were identified from Tripterygii Radix; kaempferol was the most active ingredient among 33 other components. Fourteen proteins were found to be affected in RA from 285 common biotargets. The tumor necrosis factor (TNF) signaling pathway was predicted to be one of the most latent treatment pathways. Migration of RA-FLS was inhibited and the expression of protein kinase B (AKT1), JUN, caspase 3 (CASP3), TNF receptor 1 and 2 (TNFR1 and TNFR2), interleukin-6 (IL-6), and TNF-α was significantly affected by kaempferol. Thus, this study confirmed kaempferol as the effective component of Tripterygii Radix against RA-FLS and TNF signaling pathway and its involvement in the regulation of AKT1, JUN, CASP3, TNFR1, TNFR2, IL-6, and TNF-α expression
Real-space imaging with pattern recognition of a ligand-protected Ag374 nanocluster at sub-molecular resolution
厦门大学化学化工学院郑南峰教授团队长期致力于研究固体功能材料的表界面化学行为,在分子水平上实现对固体功能材料的化学性能的调控与优化。得益于固体表面物理化学国家重点实验室的多学科合作以及能源材料化学协同创新中心的多单位优势互补,郑南峰教授课题组通过与校内外多个课题组的密切合作,近期在功能材料的可控制备、复杂表界面结构的高分辨表征和表界面过程分子机制的深入理解等方面取得系列重要进展,相关成果近期均在Nature Communications发表。
针对纳米颗粒表面配体难被高分辨直接成像的特点,与厦门大学郑兰荪、谢兆雄等教授以及中科院大连化物所杨学明研究员、马志博副研究员和芬兰于韦斯屈莱大学HannuHäkkinen教授等多个团队紧密合作,在利用扫描隧道显微镜表征金属纳米团簇的表面配体层结构方面取得重要进展。以原子结构精确的 Ag374纳米团簇为研究对象,利用超高真空扫描隧道显微镜分别在液氦及液氮温度下获得了单个团簇亚分子高分辨率的拓扑图像。【Abstract】High-resolution real-space imaging of nanoparticle surfaces is desirable for better understanding of surface composition and morphology, molecular interactions at the surface, and nanoparticle chemical functionality in its environment. However, achieving molecular or sub-molecular resolution has proven to be very challenging, due to highly curved nanoparticle surfaces and often insufficient knowledge of the monolayer composition. Here, we demonstrate sub-molecular resolution in scanning tunneling microscopy imaging of thiol monolayer of a 5 nm nanoparticle Ag374 protected by tert-butyl benzene thiol. The experimental data is confirmed by comparisons through a pattern recognition algorithm to simulated topography images from density functional theory using the known total structure of the Ag374 nanocluster. Our work demonstrates a working methodology for investigations of structure and composition of organic monolayers on curved nanoparticle surfaces, which helps designing functionalities for nanoparticle-based applications.The experimental work done in Dalian Institute of Chemical Physics (DICP),
Chinese Academy of Sciences, was supported both by Xiamen University (The
National Key R&D Program of China grant 2017YFA0207302, National Natural
Science Foundation of China, grant 21731005, 21420102001 and 21721001 the
National Key R&D Program of China grant 2017YFA0207302) and DICP (National
Natural Science Foundation of China grant 21688102, the Strategic Priority Research
Program of Chinese Academy of Science, grant XDB17000000, the National Key
Research and Development Program of the MOST of China, grant 2016YFA0200603
and the open fund of the state key laboratory of molecular reaction dynamics in DICP,
CAS, grant SKLMRD-K201707). Q.Z. thanks Dr. Huayan Yang for providing the samples
for STM imaging. S.M. and H.H. thank T. Kärkkäinen and P. Nieminen for discussions
on pattern recognition algorithms. The theoretical and computational work in the
University of Jyväskylä was funded by the Academy of Finland (grants 294217, 315549,
AIPSE program, and H.H.’s Academy Professorship). H.H. acknowledges the support
from China’s National Innovation and Intelligence Introduction Base visitor program.
S.K. thanks the Vilho, Yrjö, and Kalle Väisälä Foundation for the grant for doctoral
studies. The DFT simulations were done at the Finnish national supercomputing center
CSC and at the Barcelona Supercomputing Center (PRACE project “NANOMETALS”).
研究工作得到了科技部、国家自然科学基金委和教育部,中科院先导项目,国家重点研发计划,分子反应动力学国家重点实验室开放课题基金等项目的资助
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