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排序方式: 共有245条查询结果,搜索用时 31 毫秒
41.
Mounawer Badri Adel Zitoun Houcine Ilahi Thierry Huguet Mohamed Elarbi Aouani 《Journal of genetics》2008,87(3):241-255
Genetic variability in 10 natural Tunisian populations of Medicago laciniata were analysed using 19 quantitative traits and 12 polymorphic microsatellite loci. A large degree of genetic variability
within-populations and among-populations was detected for both quantitative characters and molecular markers. High genetic
differentiation among populations for quantitative traits was seen, with Q
ST
= 0.47, and F
ST
= 0.47 for microsatellite markers. Several quantitative traits displayed no statistical difference in the levels of Q
ST
and F
ST
. Further, significant correlations between quantitative traits and eco-geographical factors suggest that divergence in the
traits among populations may track environmental differences. There was no significant correlation between genetic variability
at quantitative traits and microsatellite markers within populations. The site-of-origin of eco-geographical factors explain
between 18.13% and 23.40% of genetic variance among populations at quantitative traits and microsatellite markers, respectively.
The environmental factors that most influence variation in measured traits among populations are assimilated phosphorus (P205) and mean annual rainfall, followed by climate and soil texture, altitude and organic matter. Significant associations between
eco-geographical factors and gene diversity, H
e
, were established in five-microsatellite loci suggesting that these simple sequence repeats (SSRs) are not necessarily biologically
neutral. 相似文献
42.
Mounawer Badri Adel Zitoun Sameh Soula Houcine Ilahi Thierry Huguet Mohamed Elarbi Aouani 《Conservation Genetics》2008,9(6):1509-1520
In this paper, we analyze the genetic variability in four Tunisian natural populations of Medicago ciliaris using 19 quantitative traits and six polymorphic microsatellite loci. We investigated the amplification transferability of
30 microsatellites developed in the model legume M. truncatula to M. ciliaris. Results revealed that about 56.66% of analyzed markers are valuable genetic markers for M. ciliaris. The most genetic diversity at quantitative traits and microsatellite loci was found to occur within populations (>80%).
Low differentiations among populations at quantitative traits Q
ST
= 0.146 and molecular markers F
ST
= 0.18 were found. The majority of measured traits exhibited no significant difference in the level of Q
ST
and F
ST
. Furthermore, significant correlations established between these traits and eco-geographical factors suggested that natural
selection should be invoked to explain the level of phenotypic divergence among populations rather than drift. There was no
significant correlation between population differentiation at quantitative traits and molecular markers. Significant spatial
genetic structure consistent with models of isolation by distance was detected within all studied populations. The site-of-origin
environmental factors explain about 9.07% of total phenotypic genetic variation among populations. The eco-geographical factors
that influence more the variation of measured traits among populations are the soil texture and altitude. Nevertheless, there
were no consistent pattern of associations between gene diversity (He) and environmental factors. 相似文献
43.
Parkinson JR Dhillo WS Small CJ Chaudhri OB Bewick GA Pritchard I Moore S Ghatei MA Bloom SR 《American journal of physiology. Endocrinology and metabolism》2008,294(4):E698-E708
Peptide YY (PYY) is secreted postprandially from the endocrine L cells of the gastrointestinal tract. PYY(3-36), the major circulating form of the peptide, is thought to reduce food intake in humans and rodents via high-affinity binding to the autoinhibitory neuropeptide Y (NPY) receptor within the arcuate nucleus. We studied the effect of early light-phase injection of PYY(3-36) on food intake in mice fasted for 0, 6, 12, 18, 24, and 30 h and show that PYY(3-36) produces an acute anorexigenic effect regardless of the duration of fasting. We also show evidence of a delayed orexigenic effect in ad libitum-fed mice injected with PYY(3-36) in the early light phase. This delayed orexigenic effect also occurs in mice administered a potent analog of PYY(3-36), d-Allo Ile(3) PYY(3-36), but not following injection of other anorectic agents (glucagon-like-peptide 1, oxyntomodulin, and lithium chloride). Early light-phase injection of PYY(3-36) to ad libitum-fed mice resulted in a trend toward increased levels of hypothalamic NPY and agouti-related peptide mRNA and a decrease in proopiomelanocortin mRNA at the beginning of the dark phase. Furthermore, plasma levels of ghrelin were increased significantly, and there was a trend toward decreased plasma PYY(3-36) levels at the beginning of the dark phase. These data indicate that PYY(3-36) injection results in an acute anorexigenic effect followed by a delayed orexigenic effect. 相似文献
44.
45.
46.
In order to investigate the reliability of the Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) for trace
element analysis of biological materials, we have carried out extensive investigations on human plasma, using an Applied Research
Laboratory’s ICP-AES. When we aspirated the untreated plasma into the spectrometer, we obtained unreliable and nonreproducible
results. However, when we pretreated the plasma by wet digestion (to destroy all the organic material), we achieved reproducible
and consistent results. It is, therefore, suggested that biological samples should be pretreated, preferably by wet digestion,
before being aspirated into the ICP-AES for analysis. 相似文献
47.
Sultan Ullah Yujin Park Muhammad Ikram Sanggwon Lee Chaeun Park Dongwan Kang Jungho Yang Jinia Akter Sik Yoon Pusoon Chun Hyung Ryong Moon 《Bioorganic & medicinal chemistry》2018,26(21):5672-5681
Pigmentation disorders are attributed to excessive melanin which can be produced by tyrosinase. Therefore, tyrosinase is supposed to be a vital target for the treatment of disorders associated with overpigmentation. Based on our previous findings that an (E)-β-phenyl-α,β-unsaturated carbonyl scaffold can play a key role in the inhibition of tyrosinase activity, and the fact that cinnamic acid is a safe natural substance with a scaffolded structure, it was speculated that appropriate cinnamic acid derivatives may exhibit potent tyrosinase inhibitory activity. Thus, ten cinnamamides were designed, and synthesized by using a Horner-Emmons olefination as the key step. Cinnamamides 4 (93.72% inhibition), 9 (78.97% inhibition), and 10 (59.09% inhibition) with either a 2,4-dihydroxyphenyl, or 4-hydroxy-3-methoxyphenyl substituent showed much higher mushroom tyrosinase inhibition at 25?µM than kojic acid (18.81% inhibition), used as a positive control. Especially, the two cinnamamides 4 and 9 having a 2,4-dihydroxyphenyl group showed the strongest inhibition. Docking simulation with tyrosinase revealed that these three cinnamamides, 4, 9, and 10, bind to the active site of tyrosinase more strongly than kojic acid. Cell-based experiments carried out using B16F10 murine skin melanoma cells demonstrated that all three cinnamamides effectively inhibited cellular tyrosinase activity and melanin production in the cells without cytotoxicity. There was a close correlation between cellular tyrosinase activity and melanin content, indicating that the inhibitory effect of the three cinnamamides on melanin production is mainly attributed to their capability for cellular tyrosinase inhibition. These results imply that cinnamamides having the (E)-β-phenyl-α,β-unsaturated carbonyl scaffolds are promising candidates for skin-lighting agents. 相似文献
48.
Ali Zohaib Muhammad Saqib Muhammad Ammar Athar Jing Chen Awais-ur-Rahman Sial Saeed Khan Zeeshan Taj Halima Sadia Usman Tahir Muhammad Haleem Tayyab Muhammad Asif Qureshi Muhammad Khalid Mansoor Muhammad Ahsan Naeem Bing-Jie Hu Bilal Ahmed Khan Ikram Din Ujjan Bei Li Wei Zhang Yun Luo Yan Zhu Cecilia Waruhiu Iahtasham Khan Xing-Lou Yang Muhammad Sohail Sajid Victor Max Corman Bing Yan Zheng-Li Shi 《中国病毒学》2018,33(5):410-417
Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a zoonotic pathogen capable of causing severe respiratory disease in humans. Although dromedary camels are considered as a major reservoir host, the MERS-CoV infection dynamics in camels are not fully understood. Through surveillance in Pakistan, nasal (n = 776) and serum (n = 1050)samples were collected from camels between November 2015 and February 2018. Samples were collected from animal markets, free-roaming herds and abattoirs. An in-house ELISA was developed to detect IgG against MERS-CoV. A total of 794 camels were found seropositive for MERS-CoV. Prevalence increased with the age and the highest seroprevalence was recorded in camels aged [ 10 years (81.37%) followed by those aged 3.1–10 years (78.65%) and B 3 years (58.19%).Higher prevalence was observed in female (78.13%) as compared to male (70.70%). Of the camel nasal swabs, 22 were found to be positive by RT-qPCR though with high Ct values. Moreover, 2,409 human serum samples were also collected from four provinces of Pakistan during 2016–2017. Among the sampled population, 840 humans were camel herders.Although we found a high rate of MERS-CoV antibody positive dromedaries (75.62%) in Pakistan, no neutralizing antibodies were detected in humans with and without contact to camels. 相似文献
49.
C. J. Burns-Cox K. P. Chandrasekhar H. Ikram T. H. Peirce J. Pilcher C. D. M. Quinlan J. Russell Rees 《BMJ (Clinical research ed.)》1971,4(5787):586-588
This paper reports a double-blind trial of a new antianginal drug, perhexiline. Fifty-five patients suffering from angina pectoris were studied for periods of 12 or 24 weeks in a cross-over comparison against a placebo in four centres in the United Kingdom and Ireland. Perhexiline was effective in most patients as judged by reducing the number of anginal attacks in 84% and the consumption of glyceryl trinitrate tablets in 64%. The major side effect, dizziness, noted in one-third of the patients, may be dose/body-weight related. Perhexiline is a valuable new agent for the treatment of patients with angina, especially those who do not respond to other antianginal agents. 相似文献
50.
I. I. Chaudhri 《Economic botany》1957,11(3):257-262
A high-yielding, naturally occurring source of ephedrine, Ephedra gerardiana, and a closely associated factory, gives West Pakistan a virtual world monopoly for the naturally produced drug. 相似文献