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1.
Resolving the conflicts between biodiversity conservation and socioeconomic development is a global pursuit for the long-run prospects of the human species. Based on Wenchuan County, a typical county in southwestern China, a group of 20 indicators quantifying regional biodiversity and socioeconomic development was established to classify and evaluate the county area spatially. A fuzzy c-means clustering (FCM) algorithm was used as the classification method. Three indices including BD, DL and DR characterizing the value of biodiversity, the level and rate of socioeconomic development of the delineated regions were formulated. The results indicated that Wenchuan County was optimally classified into 4 types of regions (region I to IV). The area percentages of the regions vary widely from 4.3 to 65.7%. The sequences of the regions on biodiversity, socioeconomic development level, and socioeconomic development rate were, respectively, IV > II > III > I, I > III > II > IV and III >I >II >IV. The spatial strategy on coordinating biodiversity conservation and regional development is to develop mainly from the east(I, II, III) and to conserve mainly in the west(IV). Eco-industry, such as eco-tourism and eco-agriculture, need to be emphasized in the process of regional development. The quantitative methods used here may have a wide applicability.  相似文献   
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Ginsenoside compound K (CK), a rare ginsenoside originating from Panax Ginseng, has been found to possess unique pharmacological activities specifically as anti-cancers. However, the role of cytochrome P450s (CYPs) in the metabolism of CK is unclear. In this study, we screened the CYPs for the metabolism of CK in vitro using human liver microsomes (HLMs) or human recombinant CYPs. The results showed that CK inhibited the enzyme activities of CYP2C9 and CYP3A4 in the HLMs. The Km and Vmax values of CK were 84.20±21.92 μM and 0.28±0.04 nmol/mg protein/min, respectively, for the HLMs; 34.63±10.48 μM and 0.45±0.05 nmol/nmol P450/min, respectively, for CYP2C9; and 27.03±5.04 μM and 0.68±0.04 nmol/nmol P450/min, respectively, for CYP3A4. The IC50 values were 16.00 μM and 9.83 μM, and Ki values were 14.92 μM and 11.42μM for CYP2C9 and CYP3A4, respectively. Other human CYP isoforms, including CYP1A2, CYP2A6, CYP2D6, CYP2E1, and CYP2C19, showed minimal or no effect on CK metabolism. The results suggested that CK was a substrate and also inhibitors for both CYP2C9 and CYP3A4. Patients using CK in combination with therapeutic drugs that are substrates of CYP2C9 and CYP3A4 for different reasons should be careful, although the inhibiting potency of CK is much poorer than that of enzyme-specific inhibitors.  相似文献   
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A potent platelet aggregation inducer (platelet aggregoserpentin) was purified from Trimeresurus gramineus snake venom by DEAE-Sephadex A-50 and Sephacryl S-300 column chromatography. It was homogeneous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It elicited dose-dependently platelet aggregation and serotonin release reaction in rabbit platelet-rich plasma and platelet suspension. Exogenous calcium was required for its activity. Creatine phosphate/creatine phosphokinase and apyrase showed no significant inhibitory effect on aggregoserpentin-induced platelet aggregation in platelet suspension. Aggregoserpentin induced aggregation in ADP-refractory platelet-rich plasma. It caused no detectable malonic dialdehyde formation in the process of platelet aggregation. Indomethacin did not inhibit aggregoserpentin-induced platelet aggregation. Mepacrine abolished preferentially its aggregating activity, while prostaglandin E1 completely blocked both aggregoserpentin-induced aggregation and release reaction. Furthermore, platelet aggregoserpentin lowered basal and prostaglandin E1-stimulated cAMP levels in platelet suspension. Nitroprusside inhibited both its aggregating and releasing activity, while verapamil preferentially blocked its aggregating activity. It is concluded that aggregoserpentin activated platelets through lowering cAMP levels or the activation of endogenous phospholipase A2, resulting in the formation of platelet activating factor, but not of prostaglandins.  相似文献   
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Abstract The fatty acid (FA) compositions for total lipids from fat body, hemolymph and flight muscle of the armyworm moths, Mythirnna separata, at rest and after tethered flight for 1 h were determined by GC and GC-MS. The composition in these tissues comprises myristic acid (1%-2%), palmitic acid (more than 35%1, palmitoleic acid (9%-11%), stearic acid (less than 1%), oleic acid (about 32%), linoleic acid (12%-17%) and linolenic acid (3%-6%). After flight, FA level in the fat body, compared to that at rest, shows a significant decline at about 20 μg/mg tissue.h-1; the concentration of FAs in hemolymph rises evidently, but change of FA content in flight muscle appears to be small. From the changes of proportional composition of FAs in fat body, hemolymph and flight muscle, it is found that the FAs selectively utilized for flight in flight muscle are predominantly the palmitic acid and oleic acid.  相似文献   
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酸水解蚕蛹制备复合氨基酸的研究   总被引:7,自引:0,他引:7  
采用硫酸水解法,以蚕蛹制取复合氨基酸产品,得到氨基酸态氮分别为9.05%和13.45%的食用复合氨基粉和精制复合氨基酸粉。食用复合氨基酸粉含有18种氨基酸,其中必需氨基酸含量为39.2%。食用复合氨基酸粉的制备方法经工厂小批量生产证实,其工艺简单易行,适合于中小企业采用,该产品的质量优良,生产成本低廉,具有市场竞争力。  相似文献   
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t-PA cDNA在CHO细胞中的高效稳定表达   总被引:1,自引:0,他引:1  
我们曾报道t-PA mRNA非翻译区序列对其表达有明显的抑制作用,在此基础上,通过对5′-UTR及3′-UTR的改造,使t-PA在COS-7细胞中的表达水平提高30倍左右。将t-PA表达质粒用电击法转染中国仓鼠卵巢细胞二氢叶酸还原酶缺陷株(CHO-dhfr),经过混合加压及筛选,在CHO细胞中高效表达了t-PA,表达水平达到5000~6000 IU/10~6细胞/24hr。重组t-PA具有与天然t-PA相同的分子量及酶活性。经过8个月连续传代,表达水平未下降,表明细胞株是稳定的,其主要指标均符合工程细胞株的要求。  相似文献   
10.
A regulatory region of the human transferrin receptor gene promoter was found to be required for increased expression in response to serum or growth factors. This region contains two elements that appear to cooperate for full responsiveness. We found that sodium orthovanadate treatment of cells significantly activated expression of promoter constructs containing these elements. 12-O-Tetradecanoylphorbol-13-acetate alone induced a twofold increase in expression but acted synergistically with vanadate to generate a highly elevated level of expression. Dibutyryl cyclic AMP alone had no effect on expression, but when added together with vanadate and 12-O-tetradecanoylphorbol-13-acetate, led to superinduction of the promoter construct. Induction of expression by these reagents was delayed several hours, and the kinetics were identical to those observed for serum induction.  相似文献   
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