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21.
王学利 《中国野生植物资源》2001,20(4):17-18,25
用正交实验结果作方差分析表明:溶剂用量对试验结果有较显著的影响(a=0.10),提取温度对试验结果也有较大的影响,而提取时间对试验结果的影响不显著。喜树叶中水溶性糖的提取最优方案是A3C2B3,即溶剂用量为60ml,提取温度80℃,提取时间60min;喜树叶水溶性糖的提取最优方案是A2C2B1,即溶剂用量为40ml,提取温度80℃,提取时间20min。通过对喜树叶与枝的成对比较分析,叶与枝的水溶性糖含量无显著差异。 相似文献
22.
In this study we construct a phylogenetic hypothesis for the relatedness among disjunct subspecies of Cyclamen repandum and its two allopatric congeners, C. creticum and C. balearicum in order to examine the evolutionary divergence of currently isolated populations across the western Mediterranean. The most
parsimonious phylogenetic tree obtained from sequencing the cpDNA trnL (UAA) intron suggests a major phylogeographic divide in southern Greece between two clades. The first clade comprises samples
of C. repandum subsp. peloponnesiacum (from the Peloponnese) and C. creticum (from Crete). The second comprises samples of C. repandum subsp. repandum (from Croatia, Italy, southern France, Corsica, Sardinia and Sicily), C. repandum subsp. rhodense (from Rhodes and Kos) and C. balearicum (from the Balearic Islands and southern France). These data suggest that C. creticum has evolved in allopatry from C. repandum subsp. peloponnesiacum and that C. balearicum and C. repandum ssp. rhodense have diverged from C. repandum subsp. repandum at its western and eastern distribution limits. At one small site on Corsica, a population of C. repandum may have introgressed with relictual populations of C. balearicum. These divergence patterns illustrate how a phylogenetic perspective can be used to better understand the evolution of endemism
in the Mediterranean flora.
Received February 19, 2001 Accepted August 22, 2001 相似文献
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E. B. Kirichenko Yu. V. Orlova D. V. Kurilov 《Russian Journal of Plant Physiology》2008,55(6):846-853
Abstrac The composition of essential oil of Artemisia lerchiana Web. plants growing in Volgograd oblast was studied. Sampling was performed from plots contrasting in climatic and soil characteristics.
Essential oil was obtained by hydrodistillation. The content of essential oil in shoot biomass increased gradually during
shoot formation, flower bud formation, and flowering beginning and then decreased. The highest content of essential oil varied
from 1.1 to 1.5% of plant dry weight at the stage of flower bud formation. More than thirty compounds were identified by gas
chromatography-mass spectrometry. The following major components were found: camphor, borneol, bornylacetate, camphene, and
1,8-cineole. Some of compounds (sesquiterpenes and sesquiterpenoids) were identified for the first time. The time-course of
accumulation of essential oil components strongly depended on habitat edaphic factors and climatic conditions during the year
of sampling. The results permit a conclusion that A. lerchiana is a valuable producer of essential oils.
Original Russian Text ? E.B. Kirichenko, Yu.V. Orlova, D.V. Kurilov, 2008, published in Fiziologiya Rastenii, 2008, Vol. 55,
No. 6, pp. 934–941. 相似文献
26.
Takatoshi Murata Tsutomu Sato Takeshi Kamoda Hiromitsu Moriyama Yasuo Kumazawa Nobuhiro Hanada 《Experimental cell research》2014
Hydrogen sulfide (H2S) is a novel gasotransmitter that plays multiple biological roles in various body systems. In addition to its endogenous production, H2S is produced by bacteria colonizing digestive organs, including the oral cavity. H2S was previously shown to enhance pro-apoptotic effects in cancer cell lines, although the mechanisms involved remain unclear. To properly assess the anti-cancer effects of H2S, however, investigations of apoptotic effects in normal cells are also necessary. The aims of this study were (1) to compare the susceptibility to H2S-induced apoptosis between the oral cancer cell line Ca9-22 and oral keratinocytes that were derived from healthy gingiva, and (2) to identify candidate genes involved in the induction of apoptosis by H2S. The susceptibility to H2S-induced apoptosis in Ca9-22 cells was significantly higher than that in keratinocytes. H2S exposure in Ca9-22 cells, but not keratinocytes, enhanced the expression of pleckstrin homology-like domain, family A, member 1 (PHLDA1), which was identified through a differential display method. In addition, PHLDA1 expression increased during actinomycin D-induced apoptosis in Ca9-22 cells. Knockdown of PHLDA1 expression by small interfering RNA in Ca9-22 cells led to expression of active caspase 3, thus indicating apoptosis induction. The tongue cancer cell line SCC-25, which expresses PHLDA1 at a high level, showed similar effects. Our data indicate that H2S is an anti-cancer compound that may contribute to the low incidence of oral cancer. Furthermore, we demonstrated the role of PHLDA1 as an apoptosis suppressor. 相似文献
27.
DNA replication is a fundamental process of the cell that ensures accurate duplication of the genetic information and subsequent transfer to daughter cells. Various pertubations, originating from endogenous or exogenous sources, can interfere with proper progression and completion of the replication process, thus threatening genome integrity. Coordinated regulation of replication and the DNA damage response is therefore fundamental to counteract these challenges and ensure accurate synthesis of the genetic material under conditions of replication stress. In this review, we summarize the main sources of replication stress and the DNA damage signaling pathways that are activated in order to preserve genome integrity during DNA replication. We also discuss the association of replication stress and DNA damage in human disease and future perspectives in the field. 相似文献
28.
Accurately estimating patient-specific rupture risk remains a primary challenge in timing interventions for abdominal aortic aneurysms (AAAs). By re-analyzing published biaxial mechanical testing data from surgically repaired human AAAs, material anisotropy emerged as a potentially important determinant of patient-specific lesion progression. That is, based on a new classification scheme, we discovered that anisotropic aneurysmal specimens correlated with increased patient age at surgery when compared with more isotropic specimens (79.7 vs. 70.9 years, p<0.002), despite no significant difference in maximum diameter. Furthermore, using an idealized axisymmetric, finite-element growth and remodeling model of AAA progression, we found that both the initial axial extent of elastin loss and ongoing damage to elastin in the shoulder region of the AAA directly affected the degree of anisotropy as the lesion evolved, with more extensive insults increasing the anisotropy. This effect appeared to be mediated by alterations in axial loading and subsequent differences in orientation of deposited collagen fibers. While the observed increased age before surgical intervention may suggest a potential benefit of anisotropic remodeling, future biaxial tests coupled with pre-surgical data on expansion rates and detailed theoretical analyses of the biostability of a lesion as a function of anisotropy will be required to verify its clinical relevance to patient-specific rupture risk. 相似文献
29.
Activity of salivary glands in secreting honey‐elaborating enzymes in two subspecies of honeybee (Apis mellifera L) 下载免费PDF全文
Aliaa A. Al‐Sherif Adel M. Mazeed Mohamed A. Ewis Emad A. Nafea El‐Seid E. Hagag Ahmed A. Kamel 《Physiological Entomology》2017,42(4):397-403
The activity of invertase, glucose oxidase and amylase in the cephalic (post‐cerebral) and thoracic salivary glands is determined in Egyptian and Carniolan honeybees (Apis mellifera L). For this purpose, three ages of worker bees are selected for enzyme assays. The results show that the three target enzymes are detected in the two glands during the three worker ages, except invertase, which cannot be detected in the cephalic gland of newly emerged bees of both subspecies. In both glands, the secretion of invertase is highest, followed by amylase and then glucose oxidase. In Carniolan bees, invertase secretion of the cephalic and thoracic glands increases gradually with age. In Egyptian bees, invertase increases with age only in the cephalic gland, whereas, in the thoracic gland, the highest secretion activity is detected in 10–15‐day‐old bees. The highest amounts of glucose oxidase and amylase in the cephalic gland are detected in newly emerged individuals of both Egyptian and Carniolan bees. In the thoracic gland, however, the highest activity of both enzymes is recorded only in newly emerged Egyptian bees. The results are discussed in the light of bee management and biological aspects of the two subspecies. 相似文献
30.