Kosteletzkya virginica (K. virginica) is used for revegetation of salt-affected coastal tidal flats and as a raw material of biodiesel. K. virginica root tuber, a biowaste with low economic value, is rich in bioactive compounds. This study aimed to extract and identify flavonoids from K. virginica root tubers. The optimal extraction conditions were 1/25 (w/v) solid/liquid ratio, 40% ethanol concentration at 40°C for 60 min. Under these conditions, 65.2 ± 3.7 mg/g total flavonoid content was extracted from the roots, which were collected from salinized soil in late autumn of the third year. Antioxidant activity was evaluated through 1,1-diphenyl-2-picrylhydrazyl, hydroxyl radical, and superoxide anion scavenging assays. The extracted flavonoids exhibited antioxidant activity in a dose-dependent manner. Five flavonoids, glucoliquiritin apioside, licoisoflavone B, 5-methoxy-7,8-diprenyl- flavone, 7,2′-dihydroxy-6,8-dimethyl-4′,5′-methylenedioxyflavan, and 5,7,4′-trihydroxy-3′-methoxy-6,8-di-Cmethylflavanone, were identified by ultra-performance liquid chromatography–tandem mass spectrometry. Our results suggest that the flavonoids of K. virginica root tubers might be potent antioxidants and can be effectively applied as an ingredient in food and natural medicine.
Objective To quantitatively analyze the effects of high background radiation area (HBRA) on the frequencies of translocation and unstable chromosome aberrations in human peripheral blood lymphocytes.Methods Based on the data from 9 published articles retrieved from 7 electronic databases,the Meta-analysis was performed to evaluate the effects of high natural background radiation (HNBR) on the frequencies of chromosome aberrations in the peripheral blood lymphocytes in 17 777 persons from HBRA and 10 386 from the control area (CA).Cochrane's Q and I2 statistics were used to evaluate heterogeneity among studies and pooling odds ratio (OR) with 95％ confidence intervals (95％ CI) were calculated using random-effect models.Publication bias was also calculated by funnel plot,Egger linear regression test and Begg rank correlation test.Results The pooling OR of translocation [OR(95％ CI) =1.57(1.10-2.24)] and unstable chromosome aberration [OR(95％ CI) =2.04(1.32-3.14)] of long-term exposed inhabitants living in HBRA were higher than control.The subgroup analysis showed that,fortranslocation,the OR (95％ CI) were 1.24 (1.09-1.42,I2 =0.00) for male,1.37 (1.17-1.60,I2 =0.00) for female,1.17 (1.05-1.30,I2 =69.50％) for adults,and 1.38 (1.25-1.51,I2 =0.00) for Chinese.For unstable chromosome aberration,the OR (95％ CI) were 3.78 (2.40-5.97,I2 =0.00) for female,2.60 (2.25-3.00,I2 =69.60％) for adults,1.03(0.85-1.24,I2 =0.00) for children,3.19 (2.46-4.13,I2 =21.60％) for Iranian,and 1.64 (1.33-2.02,I2 =0.00) for Chinese.HBRA,age and sex differences were the reasons of above heterogeneity.Conclusions To the inhabitants living in HBRA,the frequencies of translocation and unstable chromosome aberration of peripheral blood lymphocytes are higher than those in control area.More comprehensive analysis should be performed to assess the health risk in HBRA inhabitants,which may arise new stragety in radiation protection.
Key words:
High natural background radiation; Chromosome aberration; Meta-analysis
With the reform and development of higher education,new challenges are appearing in curriculum setup.In the light of the necessity of curriculum reform and in combination with actual development of furniture design and manufacture,the author discusses current problems in curriculum setup including unreasonable curriculum setup,content repetition,old contents and insufficient elective courses.The author then provides solutions to these problems,including having reasonable curriculum setup,more credit courses,innovative thinking modes and better cooperative team.
Fabry Parot interferometer has very high resolution. But the measurement range is a little smaller for the limit of the tuning range of the laser. The method of locking the slave laser to the successive resonance frequencies of the F P cavity to improve the measurement range is introduce. The Fabry Parot interferometer with larger measurement range and nanometer resolution is realized, and extends the measurement range largely.
A realistic foundation was established for the Qinling orogeny based on the historical change of orogeny. According to the research of tectonic evolution and various types of orogeny during different periods in the Qinling area, three major kinds of orogeny were recognized, that is orogeny of subduction, collision and intracontinent. Collisional orogeny can be carved up into arccontinental and continentcontinent orogeny in detail. The Qinling undergone superposed orogenies resulted from complex transform from plate tectonic system to intracontinental system since Paleozoic. Traditional orogenic model can hardly explain tectonic evolution of the Qinling as a whole.Controlled by eastern Tethys detail Qinling orogenic process developed under plate tectonics system which represents much difference with orogeny of typical plate tectonic.
Mice, infused with 2.8 μg of colchicine in 0.5 μL of saline into each hippocampus, have been shown a significant increase in the error numbers and a decrease in the latency in step down and step through tests fourteen days after the infusion. At the same time there was also a significant decrease in cAMP levels in the cortex and hippocampus. CGP36742(3 aminopropyl n butyl phosphinic acid), a GABA B receptor antagonist, at the dosage of 50 mg·kg 1 ip daily for 14 d, could attenuate the impairment of learning and memory and the decrease in cAMP levels in the mice treated by colchicine. Being used for 14 d after infused with saline in each hippocampus, CGP36742 could also improve learning and memory function and elevate cAMP levels in the cortex, hippocampus and cerebellum. The results suggest that the elevation of cAMP levels in the brain could be beneficial to learning and memory functions and GABA B receptor antagonist might be a novel type of drug to treat Alzheimer′s disease.
Virtual maintenance environment is the workplace of virtual repair disassembly and assembly and an important part of maintenance virtual realization. During the maintenance disassembly process it is easy to come to the condition that disassembled parts are complex and the disassembled parts are too many. In order to achieve good display results, resolve virtual maintenance disassembly parts and components layout problems in the 3-dimensions (3D) environment, the paper classifies the components according to the application of hierarchical division. As a result, 3D spatial distribution is simplified to multiple 2-dimensional (2D) layouts, to reduce the complexity of the layout. In the 2D layout, genetic algorithm is used to optimize for improving the quality of layout. Finally this paper applies the method to Aero-Engine high pressure compressor virtual disassembly parts and components layout, indicating that it is feasible.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)