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51.
Abstract

Gastrodigenin, also known as 4-hydroxybenzyl alcohol (HBA), is one of the main components of Gastrodia elata, which is a perfect lead compound of natural products. In order to get new active compounds, we modified the structure of HBA through esterification with carboxylic acid, and got a series of derivatives in which 4-hydroxybenzyl alcohol 2-naphthoate (NHBA) showed stronger antidepressant activity than HBA. In this paper, we firstly evaluated the antidepressant activity of NHBA by tail suspension test (TST) and forced swimming test (FST). Then, we carried out the biochemical assay and western blot to determine its mechanism. The results displayed that NHBA could increase the content of serotonin, dopamine, norepinephrine, γ-aminobutyric acid, brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) in mice brain. It suggested that NHBA exhibited an antidepressant-like effect through monoaminergic system, GABAergic system and BDNF/TrkB signaling pathways.  相似文献   
52.
Total glucosides of paeony are the active constituents of Paeoniae Radix Alba. In this study, a novel strategy was proposed to find more metabolites and the differences between paeoniflorin, albiflorin and total glucosides of paeony (TGP). This strategy was characterized as follows: firstly, the animals were divided into three groups (paeoniflorin, albiflorin and TGP) to identify the source of TGP metabolites from paeoniflorin or albiflorin; secondly, a generic information‐dependent acquisition scan for the low‐level metabolites was triggered by the multiple mass defect filter and dynamic background subtraction; thirdly, the metabolites were identified with a combination of data‐processing methods including mass defect filtering, neutral loss filtering and product ion filtering; finally, a comparative study was used in the metabolism of paeoniflorin, albiflorin and TGP. Based on the strategy, 18 metabolites of TGP, 10 metabolites of paeoniflorin and 13 metabolites of albiflorin were identified respectively. The results indicated that the hydrolysis, conjugation reaction and oxidization were the major metabolic pathways, and the metabolic sites were the glycosidic linkage, the ester bond and the benzene ring. This study is first to explore the metabolism of TGP, and these findings enhance our understanding of the metabolism and the interactions of paeoniflrin and albiflorin in TGP. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
53.
We present a 3-12 GHz compact mixer-based reflectometer (CMR) and horn antenna system, and demonstrate its use in detecting backscatter signals with a free space calibration procedure. We evaluate the frequency-domain performance of the CMR-antenna system for measuring the complex reflection coefficient of a dielectric slab and compare it with that of a commercial vector network analyzer (VNA)-antenna setup. Time-domain responses are also investigated, and show the effectiveness of this calibration method. This low-cost, compact system eliminates the need for traditional mechanical standards and a VNA, is effective in reducing reflection artifacts, and allows for flexibility in the placement of reference planes; thus it is well suited for array-based imaging applications  相似文献   
54.
目的 :分析单纯化疗与博守联合化疗对实体瘤骨转移引起疼痛治疗的效果。方法 :42例病人随机分为单纯化疗组和化疗联合博宁组 ,对疼痛缓解程度和活动能力改善等进行对照研究。结果 :化疗联合应用博宁组疼痛缓解率及肿瘤变化方面明显优于单纯联合化疗组 (P <0 .0 5 ) ,而在活动能力改善方面则无明显差别。结论 :博宁联合化疗治疗骨转移癌引起的疼痛效果优于单纯联合化疗  相似文献   
55.
为了提高现代网络信息传输的安全性,利用无理数小数点后数字的无穷性、无规律性、分布均匀性,提出一种全新的加密算法,并用它所产生的密钥流进行数字签名,实现身份验证不可抵赖、信息传输无篡改,确保信息传输的完整性、真实性,达到提高加密效率、相互认证的效果。  相似文献   
56.
A self-assembly patterning method for generation of epitaxial CoSi2 nanostructures was used to fabricate 50 nm channel-length MOSFETs. The transistors have either a symmetric structure with Schottky source and drain or an asymmetric structure with n+-source and Schottky drain. The patterning technique is based on anisotropic diffusion of Co/Si atoms in a strain field during rapid thermal oxidation. The strain field is generated along the edges of a mask consisting of 20 nm SiO2 and 300 nm Si3N4. During rapid thermal oxinitridation (RTON) of the masked silicide structure, a well-defined separation of the silicide layer forms along the edge of the mask. These highly uniform gaps define the channel region of the fabricated device. The separated silicide layers act as metal source and drain. A poly-Si spacer was used as the gate contact. The asymmetric transistor was fabricated by ion implantation into the unprotected CoSi2 layer and a subsequent out-diffusion process to form the n+-source. I–V characteristics of both the symmetric and asymmetric transistor structures have been investigated.  相似文献   
57.
本文提出一种适用于移动网络的安全管理系统,由于访问网络能够独立地对漫游用户进行认证,所以称该系统为独立式安全管理(ISM).基于ISM设计一种漫游用户的认证协议,通过对协议的比较分析可以看出,相对于其它安全管理系统,ISM的突出优点是安全责任划分清晰、认证效率高.  相似文献   
58.
For original paper see Wang and Teixeira (IEEE Microwave Wireless Comp. Lett., vol.13, p.72-4, 2003 February). In this paper, a more precise way to evaluate the actual performance of the perfectly matched layer (PML) used for the alternating direction implicit finite-difference time-domain (ADI-FDTD) method is presented. It is shown that the intrinsic numerical dispersion error of the ADI-FDTD method must be taken into account when the actual performance of the ADI-PML (as well as the ADI-FDTD method) is evaluated. Most importantly, it is demonstrated that the ADI-PMLs implemented with either the traditional manner or the way proposed in have almost the same level of accuracy when the performance of the ADI-PML is correctly evaluated.  相似文献   
59.
本文对Nd:YAG激光的三种不同方法治疗慢性肥厚性鼻炎治疗前、治疗后的鼻粘膜的临床表现及黏液毛系统的光镜、电镜进行了对照研究,对Nd:YAG激光治疗慢性鼻炎提供了理论依据。  相似文献   
60.
UC3875在超声电源功率控制系统中的应用   总被引:7,自引:0,他引:7  
根据超声波发生器的功率控制系统原理 ,阐述了移相控制策略对超声波发生器输出电压波形的影响 ,介绍了移相控制专用芯片UC3875的电路结构和使用设计方法。  相似文献   
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