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21.
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
22.
Two novel 2′-hydroxychalcone derivatives (i.e., M1 and M2) are explored in this work. We mainly focus on investigating the effects of photoexcitation on hydrogen bonds and on the excited-state intramolecular proton transfer (ESIPT) process. On the basis of calculations of electrostatic potential surface and intramolecular interactions, we verify the formation of hydrogen bond O1 H2···O3 in both S0 and S1 states. Exploring the ultraviolet–visible spectra in the liquid phase, our simulated results reappear in the experimental phenomenon. Analyzing molecular geometry and infrared stretching vibrational spectra, we confirm O1 H2···O3 is strengthened for both M1 and M2 in the S1 state. We further confirm that charge redistribution facilitates ESIPT tendency. Constructing potential energy curves, we find the ultrafast ESIPT behavior for M1, which is because of the deficiency of side hydroxyl moiety comparing with M2. This work makes a reasonable affiliation of the ESIPT mechanism for M1 and M2. We wish this paper could facilitate understanding these two novel systems and promote their applications. 相似文献
23.
L. Gao P. Hrter Ch. Linsmeier J. Gstttner R. Emling D. Schmitt-Landsiedel 《Materials Science in Semiconductor Processing》2004,7(4-6):331
Deposition of Ag films by direct liquid injection-metal organic chemical vapor deposition (DLI-MOCVD) was chosen because this preparation method allows precise control of precursor flow and prevents early decomposition of the precursor as compared to the bubbler-delivery. Silver(I)-2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octanedionato-triethylphosphine [Ag(fod)(PEt3)] as the precursor for Ag CVD was studied, which is liquid at 30 °C. Ag films were grown on different substrates of SiO2/Si and TiN/Si. Argon and nitrogen/hydrogen carrier gas was used in a cold wall reactor at a pressure of 50–500 Pa with deposition temperature ranging between 220 °C and 350 °C. Ag films deposited on a TiN/Si diffusion barrier layer have favorable properties over films deposited on SiO2/Si substrate. At lower temperature (220 °C), film growth is essentially reaction-limited on SiO2 substrate. Significant dependence of the surface morphology on the deposition conditions exists in our experiments. According to XPS analysis pure Ag films are deposited by DLI-MOCVD at 250 °C by using argon as carrier gas. 相似文献
24.
HDI工艺中取代涂树脂铜箔适合激光钻孔的半固化片 总被引:1,自引:1,他引:0
应用于HDI的激光钻孔半固化片的方法和其它常规材料相比具有的优缺点。 相似文献
25.
26.
Ji-Dong Lou Chun-Ling Gao Li Li Zhi-Gang Fang 《Monatshefte für Chemie / Chemical Monthly》2006,41(10):1071-1074
A new procedure for the selective oxidation of alcohols to the corresponding aldehydes and ketones with potassium permanganate
supported on aluminum silicate at room temperature under solvent-free conditions and shaking is reported. 相似文献
27.
应用Nd:YAG激光(波长1.06μm,功率5w,照射时间0.5-3 min)和Ar+激光(波长488nm,功率70mw,照射时间5-15min)对长期保存的不同保存形式的塔胞藻(Pyramidomonassp.)进行辐照处理。研究了不同剂量激光辐照对藻体生长和叶绿素含量的影响。实验结果表明:照射剂量为60s的Nd:YAG激光及剂量为15min的Ar+激光对液体保存形式的藻种有较明显的促长效果,接种后这两种激光处理组的比生长速率分别较对照提高达53.33%和28.89%,叶绿素含量分别增加73.33%和65.69%。两种激光对液体保存藻种的活化效果均好于固体保存种。 相似文献
28.
P. G. Muzykov Y. I. Khlebnikov S. V. Regula Y. Gao T. S. Sudarshan 《Journal of Electronic Materials》2003,32(6):505-510
To establish fast, nondestructive, and inexpensive methods for resistivity measurements of SiC wafers, different resistivity-measurement
techniques were tested for characterization of semi-insulating SiC wafers, namely, the four-point probe method with removable
graphite contacts, the van der Pauw method with annealed metal and diffused contacts, the current-voltage (I-V) technique,
and the contactless resistivity-measurement method. Comparison of different techniques is presented. The resistivity values
of the semi-insulating SiC wafer measured using different techniques agree fairly well. As a result, application of removable
graphite contacts is proposed for fast and nondestructive resistivity measurement of SiC wafers using the four-point probe
method. High-temperature van der Pauw and room-temperature Hall characterization for the tested semi-insulating SiC wafer
was also obtained and reported in this work. 相似文献
29.
30.
An optimization model for placement of wavelength converters to minimize blocking probability in WDM networks 总被引:7,自引:0,他引:7
Suixiang Gao Xiaohua Jia Chuanhe Huang Ding-Zhu Du 《Lightwave Technology, Journal of》2003,21(3):684-694
The introduction of wavelength converters in wavelength division multiplexing (WDM) networks can reduce the blocking probabilities of calls. In this paper, we study the problem of placing a given number of converters in a general topology WDM network such that the overall system blocking probability is minimized. The original contributions of this work are the following: 1) formulation of success probability in a network as a polynomial function of the locations of converters; 2) proposal of an optimization model of the converter placement problem as the minimization of a polynomial function of 0-1 variables under a linear constraint, so that standard optimization tools can be employed to solve the problem; and 3) design of a search algorithm that can efficiently find the optimal solution to the converter placement problem. Experiments have been conducted to demonstrate the effectiveness of the proposed model and the efficiency of the algorithm. 相似文献