1,616 research outputs found

    Novel Microfiber Sensor and Its Biosensing Application for Detection of hCG Based on a Singlemode-Tapered Hollow Core-Singlemode Fiber Structure

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    A novel microfiber sensor is proposed and demonstrated based on a singlemode-tapered hollow core -singlemode (STHS) fiber structure. Experimentally a STHS with taper waist diameter of 26.5 μm has been fabricated and RI sensitivity of 816, 1601.86, and 4775.5 nm/RIU has been achieved with RI ranges from 1.3335 to 1.3395 , from 1.369 to 1.378, and from 1.409 to 1.4175 respectively, which agrees very well with simulated RI sensitivity of 885, 1517, and 4540 nm/RIU at RI ranges from 1.3335 to 1.337, from 1.37 to 1.374, and from 1.41 to 1.414 . The taper waist diameter has impact on both temperature and strain sensitivity of the sensor structure: (1) the smaller the waist diameter, the higher the temperature sensitivity, and experimentally 26.82 pm/°C has been achieved with a taper waist diameter of 21.4 μm; (2) as waist diameter decrease, strain sensitivity increase and 7.62 pm/με has been achieved with a taper diameter of 20.3 μm. The developed sensor was then functionalized for human chorionic gonadotropin (hCG) detection as an example for biosensing application. Experimentally for hCG concentration of 5 mIU/ml, the sensor has 0.5 nm wavelength shift, equivalent to limit of detection (LOD) of 0.6 mIU/ml by defining 3 times of the wavelength variation (0.06 nm) as measurement limit. The biosensor demonstrated relatively good reproducibility and specificity, which has potential for real medical diagnostics and other applications

    Protective effect of Radix Bupleuri extract against liver cirrhosis in rats

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    Purpose: To explore the effect of Radix Bupleuri extract (RBE) on diethylnitrosamine (DEN)-induced liver cirrhosis in rats.Methods: Rats were injected with DEN once a week for 8 weeks to induce liver cirrhosis. Some DENinduced rats were also treated with RBE, which was obtained by extracting dried Radix Bupleuri in water, for 8 weeks. Afterwards, biochemical indices and oxidative stress markers were assessed.Results: RBE significantly decreased serum concentrations of both alanine transaminase (137.3 ± 4.4 U/L, p < 0.01) and aspartate aminotransaminase (152.1 ± 3.4 U/L, p < 0.01) in DEN-induced rats at week 8. In addition, RBE significantly decreased malondialdehyde (0.13 ± 0.02 umol/L, p < 0.01) and superoxide dismutase (0.73 ± 0.04 U/mg protein, p < 0.01) levels in DEN-induced rats (p < 0.01).Conclusion: RBE exhibits a protective effect against DEN-induced liver cirrhosis in rats. Thus, it may have the potential to be used to treat liver cirrhosis in clinical settings.Keywords: Radix Bupleuri, Liver cirrhosis, Anti-oxidant, Diethylnitrosamine, Alanine transaminase, Aspartate aminotransaminas

    Further improvement of N6 medium for callus induction and plant regeneration from maize immature embryos

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    To explore the possibility to improve N6 medium for callus induction and plant regeneration from maize immature embryos, comparative experiments were conducted to screen the optimal calcium concentration for the callus induction medium and the subculture medium modified from N6 medium and to examine the effects of uniconazole and ABT root promoting powder supplement on plant regeneration and root generation. According to the results, the calcium concentration of N6 medium was increased from 1.13 to 5 mmol/l for callus induction and subculture. Uniconazole from 0.25 and 0.5 mg/l and ABT root promoting powder of 0.5 mg/l were suggested to be supplemented to the regeneration medium and the root generation, separately. On these improved media, the frequency of callus induction, the relative proliferation rate of callus subculture, the regeneration rate and the average root biomass of the regenerated plantlets increased significantly. All these improvements facilitate the establishment of acceptor system from elite parental inbred lines of commercial hybrids and provide a solid basis for transgenic manipulation of maize.Keywords: ABT root-promoting powder, calcium, callus induction, immature embryo, maize, N6 medium, plant regeneration, uniconazol

    Historical Review about Research on “Bonghan System” in China

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    The meridian-collateral theory is the theoretical basis of acupuncture-moxibustion therapy. Professor Bonghan Kim, a professor of the Pyongyang Medical University of the Democratic People’s Republic of Korea, claimed that he found the anatomical structure of meridian-collaterals, named Bonghan corpuscles (BHCs) and Bonghan ducts (BHDs) system or primo vascular system (PVS), in 1962. From 1963 to 1965, researchers from our institute conducted a series of comparative anatomical experiments, trying to reproduce the so-called BHC- and BHD-like structures in different strains of animals. In the present paper, the authors introduced their research findings about BHC- and BHD-like structures in the young rabbit’s umbilicus including its external appearance, ectoplasm and endoplasm, and about strip-like and node-like objects in the blood vessels and lymph vessels near the larger abdominal and cervical blood vessels and chromaffin tissue in the back wall of the rabbit’s abdominal cavity and between the bilateral kidneys. In spite of existence of the BHC- and BHD-like structures in the rabbit, there has been no proved evidence for their association with the meridian-collateral system described in acupuncture medicine. In the present historical review, the authors also make a discussion about the significance of those findings

    Impact of Different Static Air-Gap Eccentricity Forms on Rotor UMP of Turbogenerator

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    Theoretical analysis and numerical FEM calculations, together with segmental experiment studies, are used to study the impact of the static air-gap eccentricity forms on the rotor unbalanced magnetic pull (UMP) of turbogenerator. The universal expression of the magnetic flux density under different forms of SAGE is firstly deduced, based on which the detailed UMP formulas for the normal condition and three SAGE cases are obtained, respectively. Then the exciting characteristics of the UMP for each SAGE form to generate vibrations are analyzed. Finally, numerical FEM calculations and segmental experiments are carried out to investigate the effect of SAGE forms on the rotor UMP, taking the SDF-9 type non-salient-pole fault simulating generator as the object. It is shown that, no matter what kind of SAGE occurs, amplitude increments at each even harmonic component of the UMP and the rotor vibration, especially the 2nd harmonic component, will be brought in. Meanwhile, the UMP keeps directing to the very position where the minimum radial air-gap is. Among the different SAGE forms, the rotor offset has the most sensitive effect on the rotor UMP and vibration, while the stator ellipse deformation has the weakest impact

    Expression of DNMT1 and DNMT3a Are Regulated by GLI1 in Human Pancreatic Cancer

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    BACKGROUND AND AIMS: GLI1, as an indispensable transcriptional factor of Hedgehog signaling pathway, plays an important role in the development of pancreatic cancer (PC). DNA methyltransferases (DNMTs) mediate the methylation of quantity of tumor-related genes. Our study aimed to explore the relationship between GLI1 and DNMTs. METHODS: Expressions of GLI1 and DNMTs were detected in tumor and adjacent normal tissues of PC patients by immunohistochemistry (IHC). PANC-1 cells were treated by cyclopamine and GLI1-siRNA, while BxPC-3 cells were transfected with overexpression-GLI1 lentiviral vector. Then GLI1 and DNMTs expression were analyzed by qRT-PCR and western blot (WB). Then we took chromatin immunoprecipitation (ChIP) to demonstrate GLI1 bind to DNMT1. Finally, nested MSP was taken to valuate the methylation levels of APC and hMLH1, when GLI1 expression altered. RESULTS: IHC result suggested the expressions of GLI1, DNMT1 and DNMT3a in PC tissues were all higher than those in adjacent normal tissues (p<0.05). After GLI1 expression repressed by cyclopamine in mRNA and protein level (down-regulation 88.1±2.2%, 86.4±2.2%, respectively), DNMT1 and DNMT3a mRNA and protein level decreased by 91.6%±2.2% and 83.8±4.8%, 87.4±2.7% and 84.4±1.3%, respectively. When further knocked down the expression of GLI1 by siRNA (mRNA decreased by 88.6±2.1%, protein decreased by 63.5±4.5%), DNMT1 and DNMT3a mRNA decreased by 80.9±2.3% and 78.6±3.8% and protein decreased by 64.8±2.8% and 67.5±5.6%, respectively. Over-expression of GLI1 by GLI1 gene transfection (mRNA increased by 655.5±85.9%, and protein increased by 272.3±14.4%.), DNMT1 and DNMT3a mRNA and protein increased by 293.0±14.8% and 578.3±58.5%, 143.5±17.4% and 214.0±18.9%, respectively. ChIP assays showed GLI1 protein bound to DNMT1 but not to DNMT3a. Results of nested MSP demonstrated GLI1 expression affected the DNA methylation level of APC but not hMLH1 in PC. CONCLUSION: DNMT1 and DNMT3a are regulated by GLI1 in PC, and DNMT1 is its direct target gene
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