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Heping, China

Qiqihar Medical University is an institution for higher education, founded in 1946 and located in Qiqihar city of Heilongjiang province in northeast China. Wikipedia.

Xu L.,Qiqihar Medical University
Journal of Convergence Information Technology | Year: 2012

How to effectively extend WSN (Wireless sensor networks) survival time with the energy of the sensor node is focused in research on the WSN routing protocol all the time. This paper proposes a new routing algorithm called as COLEH (Clustering Optimized Low Energy Hierarchy) based on the clustering protocol, optimizes the cluster division based on the uneven clustering idea and selects the cluster head according to the residual energy of the node. The simulation results indicate that this routing algorithm can effectively balance the energy consumption of the nodes and extend the life of the whole network. Source

Panax ginseng C.A. Meyer, with thousands of years of history, has been known as a valuable traditional Chinese medicine. The plant has been valued for its important biological and chemical perspectives and its use in the treatment of a variety of pathological conditions and illnesses have been documented in ethnobotanical reports. Modern pharmacological experiments have proved that ginsenosides is the most active ingredients. Most recent interest has been focused on the ginsenosides to explore the pharmacological mechanisms of P. ginseng. Whereas it is difficult to make significant progress to elucidate the underlying mechanism by which P. ginseng take effect only by ginsenoside. As we know, ginseng contains multiple constituents, such as ginsenosides, essential oil, polysaccharides and peptides, and especially more and more attentions have been cast on ginseng polysaccharides by medical scientists and nutritionists due to their various important biological activities. Therefore the aim of present review is to give a comprehensive summary of information regarding the chemical constituents and biological effects of polysaccharides form the leaves, roots and fruits of P. ginseng to help us to take action for future study in this discipline. © 2011 Elsevier Ltd. All rights reserved. Source

Zhang L.-P.,Qiqihar Medical University
Guangzi Xuebao/Acta Photonica Sinica | Year: 2012

Silicon-based channel waveguides are poled by thermal poling. A fiber-based (single mode) Mach- Zehnder interferometer is utilized to measure the linear electro-optic effect. Poling conditions (poling temperature, poling time, poling voltage) are optimized in air environment. The results show that, the electro-optic coefficient is r TM=0.059±0.001 pm/V, r TE=0.053±0.001 pm/V at the optimized conditions (-2.4 kV, 406°C, 20 min). At the same time, the waveguide has a lower threshold of poling voltage and poling temperature. An effective electro-optic signal can be observed when poling voltage drops to about 100 V or poling temperature drops to about 80°C. The results also suggest that the electro-optic coefficient increases of 15% at negative poling than positive poling. Source

Sun Y.-X.,Qiqihar Medical University | Kennedy J.F.,Institute of Advanced Science and Technology
Carbohydrate Polymers | Year: 2010

Four water-soluble purified polysaccharides (CRPsA-1, CRPsA-2, CRPsB-1 and CRPsB-2) were obtained from the fruiting bodies of Chroogomphis rutilus by DEAE Sepharose Fast Flow column chromatography and Sepharose 6 Fast Flow column chromatography. Their chemical and physical characteristics were determined by chemical methods, gas chromatography (GC) and high-performance size-exclusion chromatography (HPSEC). On the basis of hydroxyl radical assay, superoxide radical assay and Fe2+-chelating ability assay, the antioxidant activities of CRPsA-1, CRPsA-2, CRPsB-1 and CRPsB-2 were investigated. Among these fractions, CRPsB-1 and CRPsB-2 containing glucuronic acid had the higher scavenging effects on hydroxyl radicals and superoxide radicals, and more potent Fe2+-chelating activity than CRPsA-1and CRPsA-2 containing no glucuronic acid in a concentration-dependent manner. © 2010 Elsevier Ltd. All rights reserved. Source

Sun Y.-X.,Qiqihar Medical University | Liu J.-C.,Qiqihar Medical University | Kennedy J.F.,Institute of Advanced Science and Technology
Carbohydrate Polymers | Year: 2010

Response surface methodology (RSM) was used to optimize the extraction conditions of polysaccharides (CRP) from the fruiting bodies of Chroogomphis rutilus with a Box-Behnken design (BBD). Three independent variables such as extraction temperature (°C), extraction time (h) and ratio of water to raw material were investigated. The experimental data obtained were fitted to a second-order polynomial equation using multiple regression analysis. The 3-D response surface plot and the contour plot derived from the mathematical models were applied to determine the optimal conditions. The optimum extraction conditions were as follows: extraction temperature 96.6 °C, extraction time 2.7 h and ratio of water to raw material 22. Under these conditions, the experimental value of 57.7 ± 0.77 was well in close agreement with value predicted by the model. Preliminary in vitro antioxidant activity test showed CRP could scavenge hydroxyl radicals in a dose-dependent manner. © 2010 Elsevier Ltd. All rights reserved. Source

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