391 research outputs found

    Magnetization and Giant Magnetoimpedance Effect of Co-Rich Microwires under Different Driven Currents

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    Co68.25Fe4.5Si12.25B15 amorphous microwires with a diameter of 34 μm were prepared via the melt extraction method. The dependency of AC driving current Iac and frequency on giant magnetoimpedance (GMI) effect and magnetization were investigated using a 4294A impedance analyzer and the transverse Kerr effect. The GMI effect was analyzed when Iac changed from 6 mA to 20 mA at a frequency ranging from 0.1 MHz to 15 MHz. The influence of AC current dependent on the frequency is correlated with the magnetization mechanism. The maximum transverse Kerr intensity (MTKI) decreased with the increase in Iac under direct magnetic field when the frequency was below megahertz. However, MTKI values were similar with the increase of Iac when it was over 2 MHz. Meanwhile, the GMI effect was optimized by selecting an adequate value of AC driving current Ip, at which the circular permeability was higher when the frequency was not over 2 MHz. Results showed that the influence of Iac on magnetoimpedance became weak with strong skin effect and slightly stronger GMI effect driven by a higher Iac when the frequency was between 2 MHz and 15 MHz. The skin effect turned out to be the key factor to the GMI effect; thus, there were no obvious differences in magnetization and GMI effect with AC driving current changing when the frequency was as high as 15 MHz

    A sensitive and rapid HPLC-DAD method for the determination of 3-hydroxy-1,2-dimethyl-4-pyridone and its distribution in rats

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    Purpose: To establish a sensitive and rapid method for the determination of the tissue distribution of 3-hydroxy-1,2-dimethyl-4-pyridone (L1) in vivo, and its plasma protein binding capacity.Methods: This study optimized a reverse-phase HPLC method for specific and sensitive determination of L1 as well as its plasma and tissue  distributions. The optimized method was used to determine the plasma protein-binding capacity of L1 in Wistar rats.Results: A rapid, sensitive and simple HPLC-DAD method was established for studying the plasma and tissue distribution of L1. Following TI  administration, its liver concentrations peaked at 60 min and 360min, followed 360 min later with peak level in the kidney (second highest). The L1 concentration was significantly lower after 360 min than after 60 min, and values of its mean binding to plasma proteins was 5.2 % at different L1 concentrations.Conclusion: These results indicate that L1 is a drug with rapid-absorption and rapid-elimination thath is distributed widely in vivo in rats. Moreover, the drug has a weak plasma protein-binding capacity. Keywords: 3-Hydroxy-1,2-dimethyl-4-pyridone, Distribution, Alzheimer’s disease, Therap

    What They Gain Depends on What They Do: An Exploratory Empirical Research on Effective Use of Mobile Healthcare Applications

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    Mobile healthcare application receives widespread attention, although it has advanced technology and user-friendly design, when users don’t use it effectively, it seems worthless. Research mainly focus on technology improvement. But how to improve user behavior to match the technology is another essential factor for facilitating effective use from managerial perspective. We introduced the task technology fit theory to explain the mechanism when user using the applications. We added perceived e-health literacy as moderator variable, considering the user characteristic and medical environment. The data was collected from student samples of two schools (medical and non-medical related universities), totally 178 valid samples. Our research indicates adaptation and learning behavior have significantly positive impact on the efficiency use and effectiveness use. The perceived e-health literacy only has significant moderator effect on learning behavior. Our study provides practical implications for both software providers and users to achieve effective use of mobile healthcare applications

    PO-216 The Effects of Aerobic Exercise on Spatial Learning and Memory and Expression of PDE-4 in Hippocampus of the Aging Rats: There is no full text article associated whit this abstract

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    Objective To discuss the effect of aerobic exercise intervention before aging rats and on aging rats, the spatial learning and memory abilities and the expression of PDE-4 in hippocampus. Methods 64 male SD rats were divided into 4 groups at random (n=16): control group(group C), D-galactose aging model group (group A), Pre-aging aerobic exercise intervention group (group S1), Aerobic exercise intervention on aging group (group S2). After 6 weeks, each group was randomly divided into Morris water maze behavior training group (M group) and natural feeding group (N group), record as CM, AM, S1M, S2M, CN, AN, S1N, S2N. At the end of 7th week, all rats were killed and the cerebral cortex SOD, GSH-PX and MDA content were tested; The expression of PDE-4 gene in hippocampus was detected by Real-time PCR and Western blotting. Results 1) The general state: When compared to the rats in C group, which in A group show obvious symptoms of aging, such as lethargy, loss of appetite, slow, yellow curly hair color, even off signs and so on; but S2 group were similar to C group; S1 group were a little worse than S2 group. 2) HE staining: When compared to the rats in C group, the hippocampus neurons in A group were disordered, the cells staining were deepened, the cytoplasm were edema, most of the interstitial cells were loose, and other morphological structure in aging state;S2 group were similar to C group; S1 group were a little worse than S2 group.3) The free radical detection: Almost no difference in each corresponding M group and N group. The activities of the cerebral cortex SOD and GSH-PX in were consistent: C group and S2group were significantly or very significantly higher than others (P<0.05/0.01); The cerebral cortex MDA content: C group was the lowest, S2 group followed, and all significantly lower than those in A group and S1 group (P<0.05). 4)The Morris water maze test: the Positioning navigation experiment results showed that the spatial memory was preliminarily formed on the day 2, CM group, S1M group and S2M group formed stable spatial learning and memory on day 3,but that of AM group formed on day 4; The space exploration test results showed that the maximum number of times of through the site was CM group, the percentage of the original site quadrant of CM group was the highest, and there was a very significant difference with the other groups (P<0.01); S2 group followed, but AM group and S1M were relatively low. 5)The results of Real-time PCR and Western blotting: When compared to the rats in C group, which in A group and S1group were very significantly higher(P<0.01),but which in S2 group was very significantly lower (P<0.01); When compared to the rats in A group, which in S2 group was very significantly lower (P<0.01),but S1group were significantly higher(P<0.01/0.05); When compared to the rats in S1 group, which in S2 group was very significantly lower (P<0.01). Conclusions 1)Aerobic exercise can improve the antioxidant capacity of the brain, protect and repair the hippocampal neurons, change the morphological structure of hippocampal neurons, improve and maintain the brain's spatial learning and memory, and thus delay brain aging. 2)Aerobic exercise intervention can down-regulate the expression of PDE-4 gene, may directly activate the cAMP/PKA/CREB signal transduction pathway to promote the synthesis of some learning memory proteins, thereby improving the learning and memory ability of aging rats and delay brain aging. 3)The different periods of aerobic exercise on brain aging intervention were different. Aerobic exercise intervention in the aging process performed relatively well. Tip: sustained aerobic exercise need to better play its role. &nbsp
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