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11.
华西银腊梅挥发油化学成分的研究 总被引:1,自引:0,他引:1
用水蒸气蒸馏法提取华西银腊梅挥发油,并用气相色谱-质谱(GC-MS)联用技术对其挥发油的化学成分进行分析,结果共鉴定了其中的39种成分,所鉴定成分含量约占总检出量的87.83%。其化学成分主要为(Z,Z)-9,12-十八碳二烯酸甲酯(9.00%),壬醛(5.83%),二十一烷(5.69%),二十烷(5.08%),辛炔酸(4.50%),2,6,10,15-四甲基十七烷(3.93%),(Z)-6-十八烯酸甲酯(3.65%),3,8-二甲基十一烷(3.52%),1-十六碳炔(3.31%),肉豆蔻酸(2.86%),月桂醛(2.81%),壬酸(2.23%),5,6,7,7α-四氢-4,4,7α三甲基-2(4H)-苯并呋喃酮(2.18%)等。 相似文献
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For the study of genetic and physiological mechanisms of inherited stress-sensitive arterial hypertension, specific binding of ligands of alpha 1-, alpha 2- and beta-adrenoceptors was measured in 2 strains of rats: Wistar normotensive and ISSAH rats (rats with inherited stress-sensitive arterial hypertension). The maximal binding sites (Bmax) and apparent dissociation constants (Kd) were studied with the alpha 1-adrenergic antagonist 3H-prazosin, alpha 2-adrenergic agonist 3H-clonidine and 3H-dihydroalprenolol, a beta 1-receptor antagonist. Four brain regions were investigated: frontal cortex, hypothalamus, pons and medulla oblongata. In comparison with normotensive controls, hypertensive rats had significantly greater density of the alpha 1-adrenoceptors in the medulla oblongata. However, the number of hypothalamic alpha 1-adrenoceptors was significantly reduced in these animals. The same significantly lower alpha 2-adrenoreceptor density was found in the hypothalamus and the pons, and lower, beta-adrenoceptors density in the medulla oblongata. It was concluded that brain adrenoceptors are involved in the mechanisms of development of inherited stress-sensitive hypertensive syndrome. 相似文献
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Trade in freshwater ornamental fish in South Africa is currently regulated by a ‘blacklist’ to prevent potentially invasive taxa from establishing in the country. Because its effective implementation requires accurate identification, the aim of the present study was to test whether DNA barcoding is a useful tool to identify freshwater fishes in the South African pet trade. A total of 351 aquarium fish specimens, representing 185 traded taxa, were sequenced for the mitochondrial COI barcoding marker in 2011 and 2012. Lake Malawi cichlids were treated as a single group due to a lack of resolution in their COI marker, resulting in a data set of 137 successfully sequenced taxa. The Barcode Of Life Database (BOLD) and GenBank were used for taxonomic assignment comparisons. The genetic identification matched the scientific name inferred from the trade name for 60 taxa (43.8%) using BOLD, and for 67 taxa (48.9%) using GenBank. A genetic ID could not be assigned in 47 (34.3%) cases using BOLD and in 37 cases (27%) using GenBank. Whereas DNA barcoding can be a useful tool to help identify imported freshwater fishes, it requires further development of publicly available databases to become a reliable means of identification. 相似文献
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JINDŘIŠKA BOJKOVÁ KLÁRA KOMPRDOVÁ TOMÁŠ SOLDÁN SVĚTLANA ZAHRÁDKOVÁ 《Freshwater Biology》2012,57(12):2550-2567
1. Rapid expansion and intensification of anthropogenic activities in the 20th century has caused profound changes in freshwater assemblages. Unfortunately, knowledge of the extent and causes of species loss (SL) is limited due to the lack of reliable historical data. An unusual data set allows us to compare changes in the most sensitive of aquatic insect orders, the Plecoptera, at some 170 locations in the Czech Republic between two time periods, 1955–1960 and 2006–2010. Historical data (1890–1911) on assemblages of six lowland rivers allow us to infer even earlier changes. 2. Regional stonefly diversity decreased in the first half of the 20th century. Streams at lower altitudes lost a substantial number of species, which were never recovered. In the second half of the century, large‐scale anthropogenic pressure caused SL in all habitats, leading to a dissimilarity of contemporary and previous assemblages. The greatest changes were found at sites affected by organic pollution and a mixture of organic pollution and channelisation or impoundment. Colonisation of new habitats was observed in only three of the 80 species evaluated. 3. Species of moderate habitat specialisation and tolerance to organic pollution were most likely to be lost. Those with narrow specialisations in protected habitats were present in both historical and contemporary collections. 4. Contemporary assemblages are the consequence of more than a 100 years of anthropogenic impacts. In particular, streams at lower altitude and draining intensively exploited landscapes host a mere fragment of the original species complement. Most stonefly species are less frequently present than before, although their assemblages remain almost intact in near‐natural mountain streams. Our analyses demonstrate dramatic restriction of species ranges and, in some cases, apparent changes in altitudinal preference throughout the area. 相似文献
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Transcriptome‐based phylogeny of endemic Lake Baikal amphipod species flock: fast speciation accompanied by frequent episodes of positive selection 下载免费PDF全文
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Naumenko SE Latysheva TV Gilinskiĭ MA 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2008,94(5):532-538
AIM OF THE STUDY: To determine the effects of two-staged ischemic preconditioning on myocardial noradrenaline in prolonged ischemia and reperfusion. METHODS: Thirty-two male Wistar rats anesthetised with urethane randomly divided into 2 groups: group 1 (ischemic preconditioning group, n = 16), and group 2 (control, n = 16). Myocardial interstitial noradrenaline levels were measured using a microdialysis technique. Ischemic preconditioning was elicited by two episodes: 5 min of ischemia and 10 min of reperfusion. The intermittent occlusions were followed by prolonged occlusion (60 min) and reperfusion (60 min). RESULTS: An increase in interstitial noradrenaline was observed in 10 min of prolonged ischemia in group 2, and in 20 min in group 1. After 20 min of myocardial ischemia there was a significant difference between groups (p < 0.05) in interstitial noradrenaline levels. In control group, it was 60% higher. In reperfusion, noradrenaline levels decreased markedly in group 1. CONCLUSION: We suggest that ischemic preconditioning by two episodes: 5-min ischemia and 10-min reperfusion prevents excessive noradrenaline interstitial accumulation, perhaps, through protection of physiological uptake I carrier. 相似文献
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苯肼对红细胞在体衰老过程中微观流变特性的影响 总被引:2,自引:1,他引:2
在Brunara等人用苯肼使动物造成急性溶血性贫血的方法基础上,建立一种由急性溶血性贫血后,而诱发家兔幼红细胞增多的非正常生理状态的红细胞在体衰老模型,继而研究新生红细胞从产生到死亡死亡过程,即衰老过程的流变学特性的变化规律。通过对新生红细胞的压积、变形、取向及与之相应的全血的粘度、血沉等指标的连续60多天的监测,发现红细胞在衰老过程中的微观流变学特性确实有明显改变。红细胞在体衰老过程中微观流变特性逐渐变差。 相似文献
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Belokopytova Irina I. Kondaurova Elena M. Kulikova Elizabeth A. Ilchibaeva Tatiana V. Naumenko Vladimir S. Popova Nina K. 《Biochemistry. Biokhimii?a》2022,87(10):1206-1218
Biochemistry (Moscow) - The mechanisms of autism are of extreme interest due to the high prevalence of this disorder in the human population. In this regard, special attention is given to the... 相似文献