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1.
Penetration, development, and reproduction of a virulent ''Harmony'' population of Meloidogyne arenaria was studied on two nematode-resistant grape rootstocks 10-17A and 6-19B. ''Cabernet Sauvignon'' was used as a susceptible control for comparison. Plants were inoculated with 100 freshly hatched second-stage juveniles (J2) of M. arenaria. Greater numbers of J2 penetrated roots of ''Cabernet'' than 10-17A, and none penetrated roots of 6-19B 4 days after inoculation (DAI). At 7 DAI, vermiform J2 advanced to sausage-shaped J2 in roots of ''Cabernet,'' penetrated roots of 6-19B, and had egressed from roots of 10-17A. Resistant rootstocks expressed hypersensitive responses to penetrating J2 along the root epidermis, among the cortical cells, and along the differentiating vascular bundles. At 13 DAI, 68% of the J2 had attained globose stage in roots of ''Cabernet,'' whereas there was no development of vermiform J2 in roots of the other two rootstocks. The nematodes reproduced only in roots of ''Cabernet.'' Lack of development of J2 in roots of the two resistant grape rootstocks might be the result of a hypersensitive response to J2 feeding.  相似文献   

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Two new flavonol glycosides and three known flavonoids were isolated from seeds of Camellia semiserrata Chi. The structures of these new flavonol glycosides were established as kaempferol 3-O-[(2'''',3'''',4''''-triacetyl)-α-L-rhamnopyranosyl(1→3)(2''',4'''-diacetyl)-α-L-rhamnopyranosyl (1→6)-β-D-glucopyranoside] and kaempferol 3-O-[(3'''',4''''-diacetyl)-α-L-rhamnopyranosyl(1→3)(2''',4'''-diacetyl)-α-L-rhamnopyranosyl(1→6)-β-D-glucopyranoside] by spectroscopic methods. The estrogenic activity of these compounds was investigated by a recombinant yeast screening assay.  相似文献   

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东莞市人工景观结构与连接度的协整性及因果关系   总被引:1,自引:0,他引:1  
冯志新  陈颖彪  千庆兰  王帅帅 《生态学报》2015,35(14):4920-4930
城市人工景观特征逐步向城市外围自然及半自然景观渗透。近年来对快速城市化地区的景观格局特征定量化研究很多,但侧重于景观格局特征的简单分析和描述,忽略了城市空间扩展过程中,城市人工景观结构与景观连接度动态变化过程中之间的内部联系。以东莞市1988—2009年城市人工景观为研究对象,通过计算并分析景观结构与景观连接度指数,利用计量经济学中的协整概念与格兰杰因果检验方法并详细分析了这两类指数之间的具体关系。研究结果表明:(1)所选取的景观结构指数与景观连接度指数能较好地描述东莞市城市人工景观时空格局变化过程;(2)人工景观斑块类型面积(CA)与可能连通性指数(PC)存在协整关系。景观聚集度指数(AI)、蔓延度指数(CONTAG)与景观连通性指数(IIC与PC)也存在协整关系,即这些变量之间确实存在长期均衡关系;(3)格兰杰因果关系检验中,在不同滞后期的情况下,大部分的结果表明景观连接度指数(IIC与PC)是景观结构指数(CA、AI、CONTAG)的格兰杰成因,说明景观连接度指数信息有助于预测景观结构指数的变化。  相似文献   

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Inhibition of passive haemagglutination showed the presence of the allotypic specificities Aa1 Aa2, Aa3, Ab4, Ab5 and Ab6 on polypeptide subunits of rabbit IgG belonging to the phenotypes Aa1-3/Ab4-4 Aa2-2/Ab4-4, Aa3-3/Ab4-4, Aa3-3/Ab4-5 and Aa3-3/Ab4-6, prepared by oxidative sulphitolysis followed by isolation on Sephadex G-100 in 6m urea and 0.05m formic acid. The determinants Aa1, Aa2 and Aa3 were found only on H chains and Ab4, Ab5 and Ab6 only on L chains. Of the latter, Ab4 and Ab5 were found in both fractions, i.e. L1 and L2, of the light chains, while Ab6 was found only in fraction L1.  相似文献   

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Omega-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are essential nutrients for human health. However, vertebrates, including humans, have lost the abilities to synthesize EPA and DHA de novo, majorly due to the genetic absence of delta-12 desaturase and omega-3 desaturase genes. Fishes, especially those naturally growing marine fish, are major dietary source of EPA and DHA. Because of the severe decline of marine fishery and the decrease in n-3 LC-PUFA content of farmed fishes, it is highly necessary to develop alternative sources of n-3 LC-PUFA. In the present study, we utilized transgenic technology to generate n-3 LC-PUFA-rich fish by using zebrafish as an animal model. Firstly, fat1 was proved to function efficiently in fish culture cells, which showed an effective conversion of n-6 PUFA to n-3 PUFA with the n-6/n-3 ratio that decreased from 7.7 to 1.1. Secondly, expression of fat1 in transgenic zebrafish increased the 20:5n-3 and 22:6n-3 contents to 1.8- and 2.4-fold, respectively. Third, co-expression of fat2, a fish codon-optimized delta-12 desaturase gene, and fat1 in fish culture cell significantly promoted n-3 PUFA synthesis with the decreased n-6/n-3 ratio from 7.7 to 0.7. Finally, co-expression of fat1 and fat2 in double transgenic zebrafish increased the 20:5n-3 and 22:6n-3 contents to 1.7- and 2.8-fold, respectively. Overall, we generated two types of transgenic zebrafish rich in endogenous n-3 LC-PUFA, fat1 transgenic zebrafish and fat1/fat2 double transgenic zebrafish. Our results demonstrate that application of transgenic technology of humanized fat1 and fat2 in farmed fishes can largely improve the n-3 LC-PUFA production.  相似文献   

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Objective To investigate the influences on birth weight of maternal smoking during pregnancy across generations.Design Intergenerational cohort study.Participants Members of the 1958 birth cohort and their offspring and mothers.Setting England, Scotland, and Wales.Main outcome measure Birth weight.Results Information on grandmothers'' smoking during pregnancy was available for 9028 singleton offspring of 4302 female cohort members. Assuming heritable transmission through the intergenerational association, grandmothers'' smoking was predicted to result in a 34 g reduction (95% confidence interval -41 g to -28 g) in the birth weight of grandchildren. Random effects models showed a negative association between grandmothers'' smoking and birth weight of grandchildren (β regression coefficient -24 g, -50 g to 3 g), but this effect was eliminated after adjustment for maternal smoking (0 g, -26 g to 26 g).No association was evident among the offspring of non-smoking mothers (n = 6105; 14 g, -17 g to 46 g), and after adjustment for maternal birth weight, adult height and body mass index, grandmothers'' smoking was positively associated with the birth weight of grandchildren (45 g, 10 g to 80 g).Conclusion Deficits in mothers'' birth weight attributable to their mother smoking was not evident in the grandchildren.  相似文献   

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MicroRNAs (miRNAs) are small noncoding RNAs that are involved in key biological processes, including development, differentiation, and regeneration. The global miRNA expression profile that regulates the regenerative potential of the neonatal mouse heart has not been reported. We performed deep sequencing to determine the genome-wide miRNA expression profile of the neonatal mouse heart at three key ages (1, 6, and 7 days). The miRNAs at least 1.4-fold differentially expressed between the three time points were selected for further analysis. Two miRNAs (mmu-miR-22-5p and mmu-miR-338-3p) were significantly upregulated, and nine miRNAs (mmu-miR-324-5p, mmu-miR-337-5p, mmu-miR-339-5p, mmu-miR-365-1-5p, mmu-miR-500-3p, mmu-miR-505-5p, mmu-miR-542-5p, mmu-miR-668-3p, and mmu-miR-92a-1-5p) were significantly downregulated in cardiac tissue of 7-day-old mice compared to 1- and 6-day-old mice. The expression patterns of five significantly different miRNAs were verified by quantitative real-time PCR. Furthermore, the potential targets of these putative miRNAs were suggested using miRNA target prediction tools. The candidate target genes are involved in the myocardial regenerative process, with a prominent role for the Notch signaling pathway. Our study provides a valuable resource for future investigation of the biological function of miRNAs in heart regeneration.  相似文献   

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Merlinius paniculoides n. sp. is described from a bisexual Italian population found in northern Italy. This species has a coarsely annulated cuticle with approximately 30 longitudinal striae in addition to the six lateral field incisures; consequently the cuticle appears tessellate. The female tail is subcylindrical with a bluntly, rounded, non-annulated terminus. Merlinius paniculoides shares the tessellate cuticular ornamentation and the offset labial region with M. lenorus (Brown, 1956) Siddiqi, 1970 and M. tartuensis (Krall, 1959) Siddiqi, 1970. It differs from M. lenorus by the higher c and lower c'' ratios (c = 16-19 vs. 12-15 and c'' = 2.2-2,8 vs. 3.7) and greater number of longitudinal striae (28-32 vs. 24). It differs from M. tartuensis by a fewer number of annuti from stylet knob base to lip constriction (8-9 vs. 21), shorter stylet (19-21 vs. 24 μm), presence of males, and higher c'' value (c'' = 2.2-2.8 vs. 1.9).  相似文献   

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The effects of Meloidogyne incognita or M. javanica at five initial inoculum levels of 20, 100, 200, 1,000, and 2,000 eggs and infective juveniles per seedling on ''Floradade,'' ''Nemarex,'' ''Patriot,'' and ''PI 129149-2(sib)-5'' tomatoes maintained at 25 or 32.5 C were studied. The number of egg masses on roots of the susceptible cultivar Floradade was similar for both species of root-knot nematodes at either 2.5 or 32.5 C soil temperatures. At 25 C, very low numbers of egg masses were produced by both species of root-knot nematodes on Nematex, Patriot, and Lycopersicon peruvianum PI 129149-2(sib)-5. At 32.5 C, the best inoculum level for assessing resistance in these tomato genotypes was 200 eggs and infective juveniles per seedling. With 28 days of incubation, this temperature and inoculum level produced quantitative differences in resistance for both species of Meloidogyne.  相似文献   

13.
OBJECTIVE--To see whether there is a relation between grommet insertion operation and tonsillectomy rates, otolaryngology services, and deprivation scores in Scotland. DESIGN--Analysis of routine 1990 NHS data on grommet insertions and tonsillectomies in Scottish children aged 0-15 years compared with data on general practitioner and otolaryngology services and Carstairs deprivation scores. SETTING--All 15 Scottish health boards. SUBJECTS--All children aged 0-15 (1,021,933). RESULTS--Tonsillectomy was more common than grommet insertion operations in Scotland (6182:4850). Health boards with high grommet insertion rates were more likely to have low tonsillectomy rates (Spearman''s rank correlation -0.59; 95% confidence interval -0.87 to -0.03). Grommet insertion rates varied fourfold (from 2.4/1000 to 9.2/1000) and tonsillectomy rates twofold (from 3.6/1000 to 8.0/1000) across Scottish health boards. Variation between health boards had changed over the 15 years 1975-90. Variation in grommet insertion rates did not reflect variation in the supply of otolaryngology consultants (Spearman''s rank correlation -0.25). There was a non-significant tendency for high general practitioner referral rates to be associated with high grommet insertion rates, low tonsillectomy rates, and less deprived areas (Spearman''s rank correlation coefficients 0.50, -0.53, and -0.43). Deprivation (measured by Carstairs scoring for each health board) was associated with higher tonsillectomy rates (Spearman''s rank correlation 0.41; 95% confidence interval -0.22 to 0.80) and significantly lower grommet insertion rates (-0.73; -0.92 to -0.28). CONCLUSION--Social factors as well as differences in disease prevalence and medical practice need to be considered when studying variation in childhood grommet insertion and tonsillectomy rates.  相似文献   

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Thirty-eight grapevine (Vitis spp.) rootstocks were screened in pots for resistance to the dagger nematode, Xiphinema index, from 1979 to 1981. Resistance ratings were based on visible root symptoms and on changes in the nematode populations over 16 months. Nineteen of the 23 Californian hybrid rootstocks tested were resistant, as were ''Harmony'','' ''Freedom,'' ''Schwarzmann,'' and ''3309.'' Two hybrids of V. rufotomentosa, ''171-52'' and ''176-9,'' were possibly immune to X. index. The rootstocks ''ARG 1,'' '' 110 R,'' ''1202,'' and ''1616,'' which are used commercially for phylloxera resistance were susceptible.  相似文献   

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Morning plasma adrenocorticotrophic hormone (ACTH) concentrations were measured in 58 normal subjects and seven patients with pituitary-dependent Cushing''s syndrome (Cushing''s disease). Particular note was taken of the time of venepuncture. The range of values for the normal subjects irrespective of timing was 9-77 ng/l. The range between 9 0 am and 9 30 am was 9-24 ng/l. In the patients with Cushing''s disease the ACTH concentrations were in the range 39-109 ng/l. To distinguish patients with Cushing''s disease from normal subjects it is therefore important to define accurately the 9 am normal range, since these results show no overlap.  相似文献   

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β-cell mass (BCM) is known to be decreased in subjects with type-2 diabetes (T2D). Quantitative analysis for BCM would be useful for understanding how T2D progresses and how BCM affects treatment efficacy and for earlier diagnosis of T2D and development of new therapeutic strategies. However, a noninvasive method to measure BCM has not yet been developed.We developed four 18F-labeled exendin(9-39) derivatives for β-cell imaging by PET: [18F]FB9-Ex(9-39), [18F]FB12-Ex(9-39), [18F]FB27-Ex(9-39), and [18F]FB40-Ex(9-39). Affinity to the glucagon-like peptide-1 receptor (GLP-1R) was evaluated with dispersed islet cells of ddY mice. Uptake of exendin(9-39) derivatives in the pancreas as well as in other organs was evaluated by a biodistribution study. Small-animal PET study was performed after injecting [18F]FB40-Ex(9-39).FB40-Ex(9-39) showed moderate affinity to the GLP-1R. Among all of the derivatives, [18F]FB40-Ex(9-39) resulted in the highest uptake of radioactivity in the pancreas 30?min after injection. Moreover, it showed significantly less radioactivity accumulated in the liver and kidney, resulting in an overall increase in the pancreas-to-organ ratio. In the PET imaging study, pancreas was visualized at 30?min after injection of [18F]FB40-Ex(9-39).[18F]FB40-Ex(9-39) met the basic requirements for an imaging probe for GLP-1R in pancreatic β-cells. Further enhancement of pancreatic uptake and specific binding to GLP-1R will lead to a clear visualization of pancreatic β-cells.  相似文献   

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《FEBS letters》1985,191(1):154-158
In vitro studies have shown that the translational inhibitory activity of 2–5 A can be blocked by the oligoribonucleotide 2',5'-(pA)3. We have examined the effect of simultaneous introduction of inhibitor and antagonist into intact mouse cells using calcium phosphate coprecipitation. Upon introduction of 10−4 M 2',5'-(pA)3 and 10−6 M 2–5 A, inhibition of protein synthesis was prevented. Efficiency of calcium phosphate precipitation of 2–5 A in the presence or absence of 2',5'-(pA)3 was comparable. Introduction of 2',5'-(pA)3 analogs showed that nucleotides which do not bind well to the 2–5 A dependent endonuclease do not prevent 2–5 A inhibitory activity. Thus, 2',5'-(pA)3 functions as an antagonist of 2–5 A in vivo.  相似文献   

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Anti-idiotypic MK2-23 monoclonal antibody (anti-Id MK2-23 mAb), which mimics the high molecular weight melanoma-associated antigen (HMW-MAA), has been used to implement active immunotherapy against melanoma. However, due to safety and standardization issues, this approach never entered extensive clinical trials. In the present study, we investigated the usage of DNA vaccines as an alternative to MK2-23 mAb immunization. MK2-23 DNA plasmids coding for single chain (scFv) MK2-23 antibody were constructed via the insertion of variable heavy (V H) and light (V L) chains of MK2-23 into the pVAC-1mcs plasmids. Two alternative MK2-23 plasmids format V H/V L, and V L/V H were assembled. We demonstrate that both polypeptides expressed by scFv plasmids in vitro retained the ability to mimic HMW-MAA antigen, and to elicit specific anti-HMW-MAA humoral and cellular immunoresponses in immunized mice. Notably, MK2-23 scFv DNA vaccines impaired the onset and growth of transplantable B16 melanoma cells not engineered to express HMW-MAA. This pilot study suggests that optimized MK2-23 scFv DNA vaccines could potentially provide a safer and cost-effective alternative to anti-Id antibody immunization, for melanoma immunotherapy.  相似文献   

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A symbology of power is assigned to DNA and genetics both in the media and in scientific publications. The term 'genohype' was offered by Holtzman (Are genetic tests adequately regulated? Science , 286 (4539), pp. 409-410, 1999) to characterize the discourse of exaggerated claims and hyperbole attached to DNA and the effort to map the human genome. In this paper, I examine the relationship between language and ideology in a systematic search for 'genohype' in biotechnology industry investor handbooks and annual reports. Three forms for 'genohype' are identified and one of these - 'possessing nature' - is isolated as involving the making of medicine. Using the NVivo software, a search of finance-related and health-related keywords showed that 'genohype' is basically not present in this investor material. The results are interpreted as reflecting the separate domains of financial capital and intellectual capital that are the ideological theatres for the production of medical commodities.  相似文献   

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