Evolution of microstructure and nanohardness of SiC fiber-reinforced SiC matrix composites under Au ion irradiation

Abstract(#br)Evolution of microstructure and nanohardness of a new type of SiC f /SiC composite under a 6 MeV Au ion irradiation up to 90 displacements per atom at 400 °C was studied. Scanning transmission electron microscopy reveals that the irradiation has induced enrichment of carbon at the grain boundaries in the fibers. This is attributed to the accumulation of C interstitials generated by the irradiation. The disappearance of {200} diffraction ring of 3C–SiC indicates that a phase transition from 3C–SiC to Si has occurred during irradiation. In addition, the hardness of SiC fiber increased after irradiation, which is due to the pinning effect caused by irradiation-induced defects. The pyrolytic-carbon interphase that contains Si-rich nano-grains in the composite has the highest irradiation tolerance as it maintained its basic morphology and graphitic nature after a radiation damage dose up to 90 dpa. Twins are the main internal defects in the SiC matrix of the SiC f /SiC composite, which grew up and resulted in the decrease of the number of twinning boundaries under irradiation. No significant microstructure change has been observed in the SiC matrix except a limited number of dislocation loops at the peak irradiation damage region. The entire matrix still maintained its hardness after irradiation

Serum Starvation Induced Cell Cycle Synchronization Facilitates Human Somatic Cells Reprogramming

Human induced pluripotent stem cells (iPSCs) provide a valuable model for regenerative medicine and human disease research. To date, however, the reprogramming efficiency of human adult cells is still low. Recent studies have revealed that cell cycle is a key parameter driving epigenetic reprogramming to pluripotency. As is well known, retroviruses such as the Moloney murine leukemia virus (MoMLV) require cell division to integrate into the host genome and replicate, whereas the target primary cells for reprogramming are a mixture of several cell types with different cell cycle rhythms. Whether cell cycle synchronization has potential effect on retrovirus induced reprogramming has not been detailed. In this study, utilizing transient serum starvation induced synchronization, we demonstrated that starvation generated a reversible cell cycle arrest and synchronously progressed through G2/M phase after release, substantially improving retroviral infection efficiency. Interestingly, synchronized human dermal fibroblasts (HDF) and adipose stem cells (ASC) exhibited more homogenous epithelial morphology than normal FBS control after infection, and the expression of epithelial markers such as E-cadherin and Epcam were strongly activated. Futhermore, synchronization treatment ultimately improved Nanog positive clones, achieved a 15–20 fold increase. These results suggested that cell cycle synchronization promotes the mesenchymal to epithelial transition (MET) and facilitates retrovirus mediated reprogramming. Our study, utilization of serum starvation rather than additional chemicals, provide a new insight into cell cycle regulation and induced reprogramming of human cells

A Community Livelihood Approach to Agricultural Heritage System Conservation and Tourism Development: Xuanhua Grape Garden Urban Agricultural Heritage Site, Hebei Province of China

The designation, conservation and tourism development of agricultural heritage systems, which are embedded with intricate human–nature relations, could significantly influence community livelihoods. Therefore, a livelihood approach is critical for agricultural heritage conservation and the sustainability of the hosting community. Taking Guanhou Village, Xuanhua Grape Garden Urban Agricultural Heritage Site as an example, this study examines impacts of heritage conservation and tourism on the community livelihood system and its implications for community livelihood sustainability. A sustainable livelihood framework is adopted to guide the analysis. Face-to-face in-depth interviews were conducted with management officials, village leaders and village residents. The research identified the importance of Globally Important Agricultural Heritage Systems (GIAHS) designation on raising government support and public awareness on conservation. Tourism emerges as an alternative livelihood to some residents which exerts positive economic influence. However, tourism participation is currently at a low level which restricted the distribution of benefits. The sustainability of local rural livelihood is at risk due to the rapid urbanization, the decline of human resources and the insufficient integration of traditional agriculture with tourism. Practical implications were discussed to enhance local participation and tourism contribution to GIAHS conservation

Tourism Potential of Agricultural Heritage Systems

Traditional agricultural systems are threatened world-wide mainly due to the introduction of modern agricultural techniques and the emigration of farm labourers from remote rural villages. The objective of the programme 'Globally Important Agricultural Heritage Systems' (GIAHS), initiated by the Food and Agriculture Organization (FAO) of the United Nations in 2002, is dynamic conservation of traditional agricultural systems. This article addresses the definition and content of agricultural heritage systems and discusses conservation options in the light of developing rural tourism. An explorative survey was conducted in Longxian village, situated in Zhejiang Province, southern China, focusing on the tourism potential of a typical Rice-Fish Agricultural System. The identification of heritage resources is a first step in the process of transforming an agricultural landscape into a cultural tourism landscape. However, the future of these landscapes is in the hands of a range of stakeholders and depends on their capacity to manage, in a sustainable way, tourism development strategies alongside conservation policies

Effect of Astragalus Polysaccharides on Cardiac Dysfunction in db/db Mice with Respect to Oxidant Stress

Objective. Oxidant stress plays an important role in the development of diabetic cardiomyopathy. Previously we reported that Astragalus polysaccharides (APS) rescued heart dysfunction and cardinal pathological abnormalities in diabetic mice. In the current study, we determined whether the effect of APS on diabetic cardiomyopathy was associated with its impact on oxidant stress. Methods. Db/db diabetic mice were employed and administered with APS. The hematodynamics, cardiac ultra-structure, apoptosis, and ROS formation of myocardium were assessed. The cardiac protein expression of apoptosis target genes (Bax, Bcl-2, and caspase-3) and oxidation target genes (Gpx, SOD2, t/p-JNK, catalase, t/p-p38 MAPK, and t/p-ERK) were evaluated, respectively. Results. APS therapy improved hematodynamics and cardinal ultra-structure with reduced apoptosis and ROS formation in db/db hearts. In addition, APS therapy inhibited the protein expression of apoptosis target genes (Bax, Bcl-2, and caspase-3) and regulated the protein expression of oxidation target genes (enhancing Gpx, SOD2, and catalase, while reducing t/p-JNK, t/p-ERK, and t/p-p38 MAPK) in db/db hearts. Conclusion. Our findings suggest that APS has benefits in diabetic cardiomyopathy, which may be partly associated with its impact on cardiac oxidant stress

Investigating the mechanism of action of Yanghe Pingchuan Granule in the treatment of bronchial asthma based on bioinformatics and experimental validation

Background: Yanghe Pingchuan Granule (YPG) is a patented Chinese medicine developed independently by the Anhui Provincial Hospital of Traditional Chinese Medicine. For many years, it has been used for the treatment of asthma with remarkable clinical effects. However, the composition of YPG is complex, and its potential active ingredients and mechanism of action for the treatment of asthma are unknown. Materials and methods: In this study, we investigated the potential mechanism of action of YPG in the treatment of asthma through a combination of bioinformatics and in vivo experimental validation. We searched for active compounds in YPG and asthma targets from multiple databases and obtained common targets. Subsequently, a protein-protein interaction (PPI) network for compound disease was constructed using the protein interaction database for Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Finally, hematoxylin and eosin (H&E) staining, Masson staining, enzyme-linked immunosorbent assay (ELISA) analysis, immunofluorescence (IF) experiments, and Western blot (WB) experiments were performed to verify the possible mechanism of action of YPG for asthma treatment. Results: We obtained 72 active ingredients and 318 drug target genes that overlap with asthma. Serine/threonine-protein kinase (AKT1), tumor protein p53 (TP53), tumor necrosis factor (TNF), interleukin (IL)-6, IL-1β, vascular endothelial growth factor-A (VEGFA), prostaglandin-endoperoxide synthase 2 (PTGS2), caspase-3 (CASP3), mitogen-activated protein kinase 3 (MAPK3) and epidermal growth factor receptor (EGFR) were the most relevant genes in the PPI network. KEGG analysis showed a high number of genes enriched for the nuclear factor kappa-B (NF-κB) signaling pathway. Animal experiments confirmed that YPG reduced inflammatory cell infiltration and down-regulated the expression of ovalbumin-induced inflammatory factors. Furthermore, YPG treatment decreased the protein expression of NFĸB1, nuclear factor kappa B kinase subunit beta (IKBKB), vascular endothelial growth factor (VEGF), and vascular endothelial growth factor receptor 2 (VEGFR2) in lung tissue. Conclusion: YPG has a positive effect on asthma by interfering with multiple targets. Furthermore, YPG may significantly inhibit the follicle-induced inflammatory response through the NF-ĸB signaling pathway

Data for a comprehensive map and functional annotation of the human cerebrospinal fluid proteome

Knowledge about the normal human cerebrospinal fluid (CSF) proteome serves as a baseline reference for CSF biomarker discovery and provides insight into CSF physiology. In this study, high-pH reverse-phase liquid chromatography (hp-RPLC) was first integrated with a TripleTOF 5600 mass spectrometer to comprehensively profile the normal CSF proteome. A total of 49,836 unique peptides and 3256 non-redundant proteins were identified. To obtain high-confidence results, 2513 proteins with at least 2 unique peptides were further selected as bona fide CSF proteins. Nearly 30% of the identified CSF proteins have not been previously reported in the normal CSF proteome. More than 25% of the CSF proteins were components of CNS cell microenvironments, and network analyses indicated their roles in the pathogenesis of neurological diseases. The top canonical pathway in which the CSF proteins participated was axon guidance signaling. More than one-third of the CSF proteins (788 proteins) were related to neurological diseases, and these proteins constitute potential CSF biomarker candidates. The mapping results can be freely downloaded at http://122.70.220.102:8088/csf/, which can be used to navigate the CSF proteome. For more information about the data, please refer to the related original article [1], which has been recently accepted by Journal of Proteomics