1,451 research outputs found

    Danshen-Chuanxiong-Honghua Ameliorates Cerebral Impairment and Improves Spatial Cognitive Deficits after Transient Focal Ischemia and Identification of Active Compounds.

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    Previously, we only apply a traditional Chinese medicine (TCM) Danshen-Chuanxiong-Honghua (DCH) for cardioprotection via anti-inflammation in rats of acute myocardial infarction by occluding coronary artery. Presently, we select not only DCH but also its main absorbed compound ferulic acid (FA) for cerebra protection via similar action of mechanism above in animals of the transient middle cerebral artery occlusion (tMCAO). We investigated whether oral administration of DCH and FA could ameliorate MCAO-induced brain lesions in animals. By using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we analyzed four compounds, including tanshinol, salvianolic acid B, hydroxysafflor yellow A and especially FA as the putative active components of DCH extract in the plasma, cerebrospinal fluid and injured hippocampus of rats with MCAO. In our study, it was assumed that FA played a similar neuroprotective role to DCH. We found that oral pretreatment with DCH (10 or 20 g/kg) and FA (100 mg/kg) improved neurological function and alleviated the infarct volume as well as brain edema in a dose-dependent manner. These changes were accompanied by improved ischemia-induced apoptosis and decreased the inflammatory response. Additionally, chronic treatment with DCH reversed MCAO-induced spatial cognitive deficits in a manner associated with enhanced neurogenesis and increased the expression of brain-derived neurotrophic factor in lesions of the hippocampus. These findings suggest that DCH has the ability to recover cognitive impairment and offer neuroprotection against cerebral ischemic injury via inhibiting microenvironmental inflammation and triggering of neurogenesis in the hippocampus. FA could be one of the potential active compounds

    A supramolecular radical cation: folding-enhanced electrostatic effect for promoting radical-mediated oxidation.

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    We report a supramolecular strategy to promote radical-mediated Fenton oxidation by the rational design of a folded host-guest complex based on cucurbit[8]uril (CB[8]). In the supramolecular complex between CB[8] and a derivative of 1,4-diketopyrrolo[3,4-c]pyrrole (DPP), the carbonyl groups of CB[8] and the DPP moiety are brought together through the formation of a folded conformation. In this way, the electrostatic effect of the carbonyl groups of CB[8] is fully applied to highly improve the reactivity of the DPP radical cation, which is the key intermediate of Fenton oxidation. As a result, the Fenton oxidation is extraordinarily accelerated by over 100 times. It is anticipated that this strategy could be applied to other radical reactions and enrich the field of supramolecular radical chemistry in radical polymerization, photocatalysis, and organic radical battery and holds potential in supramolecular catalysis and biocatalysis

    Neutron Energy Spectrum Measurements with a Compact Liquid Scintillation Detector on EAST

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    A neutron detector based on EJ301 liquid scintillator has been employed at EAST to measure the neutron energy spectrum for D-D fusion plasma. The detector was carefully characterized in different quasi-monoenergetic neutron fields generated by a 4.5 MV Van de Graaff accelerator. In recent experimental campaigns, due to the low neutron yield at EAST, a new shielding device was designed and located as close as possible to the tokamak to enhance the count rate of the spectrometer. The fluence of neutrons and gamma-rays was measured with the liquid neutron spectrometer and was consistent with 3He proportional counter and NaI (Tl) gamma-ray spectrometer measurements. Plasma ion temperature values were deduced from the neutron spectrum in discharges with lower hybrid wave injection and ion cyclotron resonance heating. Scattered neutron spectra were simulated by the Monte Carlo transport Code, and they were well verified by the pulse height measurements at low energies.Comment: 19 pages,10 figures, 1 tabl

    Laser-scribed graphene for sensors: preparation, modification, applications, and future prospects

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    Sensors are widely used to acquire biological and environmental information for medical diagnosis, and health and environmental monitoring. Graphene is a promising new sensor material that has been widely used in sensor fabrication in recent years. Compared with many other existing graphene preparation methods, laser-scribed graphene (LSG) is simple, low-cost, environmentally friendly, and has good conductivity and high thermal stability, making it widely used in the sensor field. This paper summarizes existing LSG methods for sensor fabrication. Primary LSG preparation methods and their variants are introduced first, followed by a summary of LSG modification methods designed explicitly for sensor fabrication. Subsequently, the applications of LSG in stress, bio, gas, temperature, and humidity sensors are summarized with a particular focus on multifunctional integrated sensors. Finally, the current challenges and prospects of LSG-based sensors are discussed

    A Novel Lateral Flow Assay Based on GoldMag Nanoparticles and Its Clinical Applications for Genotyping of MTHFR C677T Polymorphisms

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    Current techniques for single nucleotide polymorphisms (SNP) detection require tedious experimental procedures and expensive and sophisticated instruments. In this study, a visual genotyping method has been successfully established via combining ARMS-PCR with gold magnetic nanoparticles (GoldMag)-based lateral flow assay (LFA) and applied to the genotyping of methylenetetrahydrofolate reductase (MTHFR) C677T. C677T substitution of the gene MTHFR leads to an increased risk of diseases. The genotyping result is easily achievable by visual observation within 5 minutes after loading of the PCR products onto the LFA device. The system is able to accurately assess a broad detection range of initial starting genomic DNA amount from 5 ng to 1200 ng per test sample. The limit of detection reaches 5 ng. Furthermore, our PCR-LFA system was applied to clinical trials for screening 1,721 individuals on the C677T genotypes. The concordance rate of the genotyping result detected by PCR-LFA was up to 99.6% when compared with the sequencing results. Collectively, our PCR-LFA has been proven rapid, accurate, sensitive, and inexpensive. This new method is highly applicable for C677T SNP screening in the laboratories and clinical practices. More promisingly, it could also be extended to the detection of SNPs of other genes

    Universal Neonatal Hearing Screening Program in Shanghai, China: An Inter-Regional and International Comparison

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    Objective: By comparing the Universal Neonatal Hearing Screening (UNHS) program as implemented in Shanghai and other regions in China and countries around the world, this study makes an assessment of the Shanghai model and summarizes the experiences implementing the UNHS program, so as to provide a valuable reference for other countries or regions to carry out UNHS more effectively. Since Shanghai is one of the most developed regions in China, we also examined the relationship between economic development and the UNHS starting year and coverage rate. Methods: The study conducted a systematic review of published studies in Chinese and English on the program status of neonatal hearing screening to compare and analyze the implementation of the UNHS program in 20 cities or provinces in China and 24 regions or countries around the world. The literature search in Chinese was conducted in the three most authoritative publication databases, CNKI (China National Knowledge Infrastructure), WANFANGDATA, and CQVIP (http://www.cqvip.com/). We searched all publications in those databases with the keywords “neonatal hearing screening” (in Chinese) between 2005 and 2014. English literature was searched using the same keywords (in English). The publication database included Medline and Web of Science, and the search time period was 2000–2014. Results: Shanghai was one of the first regions in China to implement UNHS, and its coverage rate was among the top regions by international comparison. The starting time of the UNHS program had no relationship with the Gross Domestic Product (GDP) per capita in the same year. Economic level serves as a threshold for carrying out UNHS but is not a linear contributor to the exact starting time of such a program. The screening coverage rate generally showed a rising trend with the increasing GDP per capita in China, but it had no relationship with the area\u27s GDP per capita in selected regions and countries around the world. The system design of UNHS is the key factor influencing screening coverage. Policy makers, program administrators, and cost-sharing structures are important factors that influence the coverage rates of UNHS. Conclusion: When to carry out a UNHS program is determined by the willingness and preference of the local government, which is influenced by the area\u27s social, political and cultural conditions. Mandatory hearing screening and minimal-cost to no-cost intervention are two pillars for a good coverage rate of UNHS. In terms of system design, decision-making, implementation, funding and the concrete implementation plan are all important factors affecting the implementation of the UNHS

    Effects of a particular heptapeptide on the IFN-α-sensitive CML cells

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    Abstract: Using the phage display biopanning technique, we have previously identified a heptapeptide KLWVIPQ which specifically bind to the surface of the IFN-α sensitive but not the IFN-α-resistant CML cells. The effects of this heptapeptide to the IFN-α-sensitive CML cells were investigated in the present study. IFN-α-sensitive KT-1/A3 and IFN-α-resistant KT-1/A3R CML cells were transfected by pEGFP KLWVIPQ expression vector and/or induced by IFN-α. WST-1 cell proliferation assay, flow cytometry and western blotting were performed to determine the effects of this heptapeptide and/or IFN-α on CML cells. The viability of the KT-1/A3 cells w as inhibited and apoptosis was induced by either expression of the heptapeptide KLWVIPQ or IFN-α treatment with concurrent up-regulation of P53 and down-regulation of P210bcr/abl. However, these effects were not observed in the IFN-α-resistant KT-1/A3R cells. These results suggest that the heptapeptide KLWVIPQ shares a similar mechanism w ith IFN-α in the regulat ion of CML cell growth and apoptosis, implying that the heptapeptide KLWVIPQ could be a novel target to go further into mechanisms of IFN-α sensitivity and/or resistance in CML

    Impact of the tissue factor pathway inhibitor gene on apoptosis in human vascular smooth muscle cells

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    Tissue factor pathway inhibitor (TFPI) plays a vitally important role in the blood coagulation pathway. Recent studies indicated that TFPI induces apoptosis in vascular smooth-muscle cells (VSMCs) in animals. The present study investigated whether the TFPI gene could also induce apoptosis in human vascular smooth-muscle cells (hVSMCs). Such cells were isolated from human umbilical arteries and subsequently transfected with pIRES-TFPI plasmid (2 μg/mL). MTT assaying and cell counting were applied to measure cell viability and proliferation, RT-PCR was utilized to analyze TFPI gene expression in the cells. Apoptosis was analyzed by fluorescence activated cell sorting (FACS). Several key proteins involved in apoptosis were examined through Western blotting. It was shown that TFPI gene transfer led to its increased cellular expression, with a subsequent reduction in hVSMC proliferation. Further investigation demonstrated that TFPI gene expression resulted in lesser amounts of procaspase-3, procaspase-8 and procascase-9, and an increased release of mitochondrial cytochrome c (cyt-c) into cytoplasm, thereby implying the involvement of both extrinsic and intrinsic pathways in TFPI gene-induced apoptosis in hVSMCs
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