首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   17篇
  免费   0篇
  2021年   2篇
  2018年   2篇
  2017年   1篇
  2015年   1篇
  2011年   5篇
  2009年   1篇
  2005年   1篇
  2001年   2篇
  1989年   1篇
  1971年   1篇
排序方式: 共有17条查询结果,搜索用时 31 毫秒
1.
2.
The effect of the deficiency in mineral nutrients was investigated in plant species representing various adaptation groups (stress-tolerant, competitive, and ruderal plants). Dry and fresh weight, as well as the length of shoots and underground organs, were determined in 20- to 50-day-old seedlings. The ratio between the dry weights of shoot and root (SRR), relative growth rate (RGR), the rate of total dark respiration (R), gross photosynthesis (P g), and the proportion of the respiratory expenditures to gross photosynthesis (R/P g) were calculated. When affected by a deficiency in mineral nutrients, the weight of the whole plant decreased. In resistant species of clover (Trifolium pratense L.) and alfalfa (Medicago sativa L.), this reduction was insignificant, whereas, in the ruderal species amaranth (Amaranthus retroflexus L.), it was at its highest. In all the species investigated, the ratio R/P g was 38–46%. Under stress conditions, this index increased. Given a deficiency in mineral nutrients, the changes in SRR, RGR, and R/P g were greater in amaranth, suggesting that this plant species is less tolerant to stress. The correlation between RGR and R observed in amaranth under normal conditions indicates that the major energy expenditures are associated with growth. Under stress conditions, such a correlation was not observed. In more resistant species of clover and alfalfa, a weak positive correlation between RGR and R was observed both under normal and stress conditions. In these species, the deficiency in mineral nutrients probably brought about a reduction in the growth component of total dark respiration and a rise in the adaptation component. The complex of indices (R/P g, RGR, and SRR) and the extent of their variation in the seedlings describe the potential productivity and resistance of particular species to a deficiency in mineral nutrients and may characterize the adaptation type of the plants.  相似文献   
3.
Bronchial asthma is a chronic inflammatory respiratory disease caused by a complex interaction of environmental influences and genetic susceptibility. The first genome-wide association study of bronchial asthma discovered a significant association between single nucleotide polymorphisms (SNPs) located within the genomic region 17q12-q21 and childhood bronchial asthma in individuals of European descent. This result was later replicated in a number of independent population samples of European and Asian origin. Here we report the results of the first genome-wide association study of bronchial asthma in the Volga-Urals region of Russia. The study involved 358 unrelated patients with physician-diagnosed bronchial asthma and 369 disease-free control subjects of different ethnicity (Russians, Tatars, and Bashkirs). DNA specimens were genotyped using an Illumina Human610 quad array as a part of the GABRIEL project (EC contract no. LSHB-CT-2006-018996). After QC filtering procedures, a final set of 550 915 SNPs genotyped in 330 patients and 348 controls was tested for association with bronchial asthma. Five markers on chromosome 17q12-21 showed significant association with bronchial asthma (p ≤ 4.79 × 10−7). The rs7216389 SNP located in GSDMB intron 1 showed the strongest evidence for association (p = 1.01 × 10−7). Association with childhood asthma (p = 1.97 × 10−6 for rs7216389) was stronger than with late-onset asthma (p = 1.8 × 10−4 for rs7216389). A replication study of three SNPs located within GSDMB confirmed association only with childhood asthma. In sum, these results suggest that genetic variants of 17q12–q21 play an important role in susceptibility to bronchial asthma in the Volga-Urals region of Russia.  相似文献   
4.
Serine proteinases and Kunitz type inhibitors are widely represented in venoms of snakes from different genera. During the study of the venoms from snakes inhabiting Russia we have cloned cDNAs encoding new proteins belonging to these protein families. Thus, a new serine proteinase called nikobin was identified in the venom gland of Vipera nikolskii viper. By amino acid sequence deduced from the cDNA sequence, nikobin differs from serine proteinases identified in other snake species. Nikobin amino acid sequence contains 15 unique substitutions. This is the first serine proteinase of viper from Vipera genus for which a complete amino acid sequence established. The cDNA encoding Kunitz type inhibitor was also cloned. The deduced amino acid sequence of inhibitor is homologous to those of other proteins from that snakes of Vipera genus. However there are several unusual amino acid substitutions that might result in the change of biological activity of inhibitor.  相似文献   
5.
Journal of Applied Phycology - The present study aimed to characterize in vitro antioxidant properties of red algae (Gracilaria birdiae) powder and to investigate its potential protective and...  相似文献   
6.
Homogeneous protein of staphylococcal enterotoxin type E has been isolated. The technique of isolation, permitting 48% yield of active material, includes concentration by ammonium sulfate precipitation, ion exchange chromatography on DEAE-cellulose and gel-filtration on sephacryl S-200. The molecular mass of the isolated protein is 32 Kd. Antigenic affinity of staphylococcal toxins types A and E has been established by immunochemical analysis.  相似文献   
7.
Determining links between plant defence strategies is important to understand plant evolution and to optimize crop breeding strategies. Although several examples of synergies and trade-offs between defence traits are known for plants that are under attack by multiple organisms, few studies have attempted to measure correlations of defensive strategies using specific single attackers. Such links are hard to detect in natural populations because they are inherently confounded by the evolutionary history of different ecotypes. We therefore used a range of 20 maize inbred lines with considerable differences in resistance traits to determine if correlations exist between leaf and root resistance against pathogens and insects. Aboveground resistance against insects was positively correlated with the plant's capacity to produce volatiles in response to insect attack. Resistance to herbivores and resistance to a pathogen, on the other hand, were negatively correlated. Our results also give first insights into the intraspecific variability of root volatiles release in maize and its positive correlation with leaf volatile production. We show that the breeding history of the different genotypes (dent versus flint) has influenced several defensive parameters. Taken together, our study demonstrates the importance of genetically determined synergies and trade-offs for plant resistance against insects and pathogens.  相似文献   
8.
The aim of this work was to estimate the trypsin inhibitor activity (TIA) in seeds of cultivated pea varieties, wild varieties and selected crosses between varieties from the first group and wild pea varieties and to study the variation in genes coding trypsin inhibitors. Mean TIA in field pea varieties ranged from 3.12 TIU/mg of sample in field pea variety from Czech Republic to 12.90 TIU/mg of sample in field pea variety FP S4 of Serbian origin. Wild field pea varieties showed TIA between 0.98 TIU/mg of sample in Pisum elatius and 9.79 TIU/mg of sample in Pisum abyssinicum. Selected crosses between cultivated field pea varieties and Pisum elatius showed a decrease in TIA in comparison with a parent line that has higher TIA content. The PCR amplification resulted in variety-specific amplification. Varieties with low TIA activity showed amplification with At13/At5 primer pair, while varieties with higher TIA activity showed amplification with primer pairs At12/At5, At14/At5 and At14/At8. Thus, At13/At5 primer pair could be sufficient to distinguish most varieties. These markers can be applied during an early screening of the valuable materials for future breeding programs of pea cultivars with the low level of tripsin inhibitor.  相似文献   
9.
Purpose: Vegetation plays a very important role in industrial regions in terms of not only air purification, but also oxygen enrichment, air humidity, and city aesthetics. The paper presents the authors’ study of oleaster mildew during 2012–2013 in the cities of Pavlodar, Ekibastuz, and Aksu. Method: The species composition of mildew, patterns of its growth and reproduction, seasonal dynamics, and the level of trees infection according to a six-score scale were determined. Result: Three cultivars of mildew from three genera were registered. The species composition of mildew of oleaster is studied for the first time in large industrial cities of the Pavlodar region. The comparative analysis of the systematic structure of phytopathogenic fungi was followed by the study of the micro flora of green planting in megalopolises. The seasonal dynamics of growth, development, and reproduction was determined. The impact of pests on host-plants was studied. Conclusion: Timely diagnosis and localization of disease outbreak increases the likelihood of successful treatment and saving of plants.  相似文献   
10.
Bronchial asthma is a chronic inflammatory respiratory disease that is caused by the complex interaction of environmental influences and genetic susceptibility. The first genome-wide association study of bronchial asthma discovered a significant association between SNPs within 17q12-21 genomic region and childhood bronchial asthma in individuals of European descent. Association with this genomic region was then replicated in a number of independent samples of European and Asian descent. Here we report results of the first genome-wide association study of bronchial asthma in the Volga-Ural region of Russia. The present study includes 358 unrelated patients with physician-diagnosed bronchial asthma and 369 disease-free control subjects of different ethnic origin (Russians, Tatars and Bashkirs). Genotyping of DNA samples was carried out using the Illumina Human610 quad array as a part of GABRIEL project (contract from the EC No LSHB-CT-2006-018996). After QC filtering procedures, a final set of 550915 SNPs genotyped in 330 cases and 348 controls was tested for association with bronchial asthma. Five markers on chromosome 17q12-21 showed statistically significant association with bronchial asthma (p < or = 4.79 x 10(-7)). SNP rs7216389 with the strongest evidence for association (p = 1.01 x 10(-7)) is located within the first intron of the GSDMB gene. Evidence for association was stronger with childhood-onset asthma (p = 1.97 x 10(-6) for SNP rs7216389) compared to late-onset asthma (p = 1.8 x 10(-4) for SNP rs7216389). Our replication study using three SNPs within GSDMB gene confirmed association with only childhood-onset asthma. In summary, these results suggest an important role for genetic variants within 17q12-q21 region in the development of bronchial asthma in the Volga-Ural region of Russia.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号