排序方式: 共有105条查询结果,搜索用时 15 毫秒
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Gunes A Inal A Alpaslan M Eraslan F Bagci EG Cicek N 《Journal of plant physiology》2007,164(6):728-736
It has been proposed that salicylic acid (SA) acts as an endogenous signal molecule responsible for inducing abiotic stress tolerance in plants. The effect of varying salicylic acid (SA) supply (0, 0.1, 0.5 and 1.0mM) on growth, mineral uptake, membrane permeability, lipid peroxidation, H(2)O(2) concentration, UV-absorbing substances, chlorophyll and carotenoid concentrations of NaCl (40 mM) stressed maize (Zea mays L.) was investigated. Exogenously applied SA increased plant growth significantly both in saline and non-saline conditions. As a consequence of salinity stress, lipid peroxidation, measured in terms of malondialdehyde (MDA) content and membrane permeability was decreased by SA. UV-absorbing substances (UVAS) and H(2)O(2) concentration were increased by increasing levels of SA. SA also strongly inhibited Na(+) and Cl(-) accumulation, but stimulated N, Mg, Fe, Mn and Cu concentrations of salt stressed maize plants. These results suggest that SA could be used as a potential growth regulator to improve plant salinity stress resistance. 相似文献
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Orkun B. Kovanci Bahattin Kovanci Nimet S. Gencer 《Biocontrol Science and Technology》2007,17(5):457-472
The species composition and relative abundance of predatory arthropod fauna were studied in organic strawberry fields in northwestern Turkey using sweep net sampling and pitfall trapping (activity density). Arachnida constituted 13.1 and 11.5% of the sweep net and pitfall trap catches, respectively. Among the predatory insects, the most abundant groups were Heteroptera (26.7%), Diptera (25.9%), Coleoptera (16.9%) and Orthoptera (10.8%) in sweep net samples. Coleoptera (84.2%) dominated the pitfall trap catches. Many aphid specific and polyphagous predators reached peak abundance during June and July. Pearson's two-tailed correlations showed a significant and positive relationship between syrphid, coccinellid or chrysopid predator numbers and strawberry aphid density. Aphid density was not significantly correlated with carabid or with nabid abundance. Examination of spatial distribution patterns of all predatory arthropod groups using Taylor's Power Law indicated that most arthropod predators, except carabids, exhibited aggregated dispersion patterns. Coccinellids changed their spatial patterns from a uniform to an aggregated distribution through the season. There was also a significant linear correlation between Anterastes sp. abundance (larvae+adults) and Isophya rectipennis+Poecilimon ricteri (larvae+adults) density at both locations. We observed, for the first time, Anterastes preying on Isophya and Poecilimon species. The seasonal abundance of the major predatory groups were described, and their potential importance in controlling strawberry aphid and other pests is discussed. 相似文献
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Canada generates approximately 1.45 x 10(8)t of residual biomass per year, containing an estimated energy value of 2.28 x 10(9)GJ, which is equivalent to about 22% of Canada's current annual energy use. Anaerobic digestion of these biomass residues using conventional technologies could generate 1.14 x 10(10)m(3)/year of CH(4) with a heating value of 4.56 x 10(8)GJ. Conversion of these residues using emerging technologies that favor the synthesis of H(2) and represses the synthesis of CH(4) could generate 1.47 x 10(10)m(3)/year renewable H(2), with a heating value of 1.89 x 10(8)GJ. While CH(4)-production results in a larger amount of energy recovery, generating H(2) from waste biomass is a renewable alternative that could fuel the hydrogen economy. Additional research to further both the technical and commercial development of microbial bio-energy from biomass is warranted. 相似文献
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Cicek C Karatas T Altuglu I Koturoglu G Kurugol Z Bilgic A 《The new microbiologica》2007,30(2):113-118
The aim of the study was to compare an enzyme immunoassay method with shell vial cell culture method for detection of rotavirus in fecal specimens. In addition, the correlation between laboratory results and clinical scores of patients with gastroenteritis was evaluated. A total of 219 fecal specimens from children (ages 3 weeks to 5 years) with acute gastroenteritis submitted to pediatric emergency room were evaluated by both ELISA and shell vial cell culture. A Vesikari score was used for assessing the severity of the illness. Among 219 stool samples tested, 107 (48.9%) were determined to be positive. Two specimens were positive by shell vial cell culture method while they were ELISA negative. According to these results the calculated sensitivity, specificity, PPV, and NPV of ELISA were 98.1%, 100%, 100%, and 98.2%, respectively. The mean severity score for the 107 episodes of rotavirus diarrhoea was 11.0 +/- 3.6 compared to 4.5 +/- 1.9 for the 112 episodes of non-rotavirus diarrhea in the same population. Our study indicates that ELISA, which is easier to perform, faster and cheaper than cell culture methods may be suitable for routine diagnosis of rotavirus infections. The severity of rotavirus positive gastroenteritis was significantly higher than that of rotavirus negative patients. 相似文献
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BACKGROUND: The aim of this study was to ascertain whether oxidative stress is a causative factor of migraine attacks for Helicobacter pylori-infected migraineurs. MATERIALS AND METHODS: A total of 35 consecutive migraine patients without aura who came to gastroenterology polyclinic with various complaints and diagnosed H. pylori infection were included in the study group and compared with a group of 29 patients (control group) without migraine and H. infection. H. pylori infection was diagnosed by histopathological biopsies, which were taken by endoscopy (Olympus-GIFXQ240 endoscope). Both the diagnosis and the classification of migraine were made according to the International Headache Society criteria. Blood samples for nitric oxide were taken from patients with migraine during headache-free period as well as the control group. The interaction of nitric oxide was measured by the determination of both nitrite and nitrate concentrations in the sample. RESULTS: The study group included 31 women and 4 men (mean age 49 +/- 8 years) and the control group included 25 women and 4 men (mean age 52.6 +/- 11 years). The mean frequency of migraine attacks was 2.94 +/- 1.58 days/month and the mean duration of attacks was 21.2 +/- 3 hours. It was found that the study group has lower nitrate levels than the control group. CONCLUSIONS: Our results do not support the role of oxidative stress in patients suffering from H. pylori infection and migraine. 相似文献
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Sylvi Haldorsen Hasan Akan Bahattin ?elik Manfred Heun 《Vegetation History and Archaeobotany》2011,20(4):305-318
The domestication of the Neolithic founder crops of the Near East has recently been a topic of debate particularly with respect
to how rapidly the domestication of these crops occurred. One school of thought maintains that these processes lasted several
thousand years (‘protracted model’ with ‘gathering’, ‘cultivation’ and ‘domestication’ as three stages of a continuum, each
taking up to several thousand years), while another favors the view that domestication occurred much more quickly, over several
hundred years at most (‘rapid transition’). Our study focuses on one of these crops, 1-grained domesticated Einkorn wheat,
incorporating data from geology, vegetation history, and climate. In the Karacadağ region of southeastern Turkey, where 1-grained
Einkorn wheat was domesticated, the climate was severe (i.e. cold and dry) during the Younger Dryas. The climate of the Younger
Dryas acted as boundary during which a) conditions were not suitable for ‘cultivation’, and b) Einkorn would have retreated
to refugia exhibiting more suitable moisture-bearing soils that would have made ‘gathering’ difficult. Around 11600 cal. b.p., the Younger Dryas ended and a very rapid climatic amelioration commenced at the beginning of the Early Holocene, enabling
grasses to spread throughout the region. A ritual PPNA/PPNB site (G?bekli Tepe) and associated PPNB settlements such as Nevali
?ori and ?ay?nü were established at this time. In the settlements of Nevali ?ori and Cafer H?yük, the oldest domesticated
Einkorn was found in the earliest archaeological layers. This confirms that the inhabitants made use of domesticated 1-grained
Einkorn from the very beginning of settlement activity, although they continued to practice a mixed lifestyle as hunter-gatherers
and farmers. For ?ay?nü the issue is more complex, but here domesticated Einkorn also appears around the same time. In summary,
by 10400 cal. b.p. domesticated 1-grained Einkorn was present in large quantities at a variety of sites. This would give a maximum window of
time lasting approximately 1,200 years and is therefore not in agreement with the ‘protracted’ model but would be consistent
with a ‘rapid transition’. It is improbable that the ‘cultivation’ of wild Einkorn was practiced in the Karacadağ region,
since wild Einkorn was plentiful during the favorable growing conditions following the Younger Dryas, making it more likely
that ‘gathering’ would have been practiced. Because Einkorn has not been found in early settlements in the southern Levant,
this crop cannot have been ‘gathered’ and ‘cultivated’ there but instead was ‘domesticated’ independently and solely in southeastern
Turkey. Therefore, the YD acts as a boundary, providing a maximum time frame for 1-grained Einkorn domestication. 相似文献
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Cicek E Sutcu R Gokalp O Yilmaz HR Ozer MK Uz E Ozcelik N Delibas N 《Molecular and cellular biochemistry》2005,277(1-2):131-135
Isoniazid (INH) has neurotoxic effects such as seizure, poor concentration, subtle reduction in memory, anxiety, depression and psychosis. INH-induced toxic effects are thought to be through increased oxidative stress, and these effects have been shown to be prevented by antioxidant therapies in various organs. Increased oxidative stress may be playing a role in these neurotoxic effects. N-methyl D-aspartat receptors (NMDA) are a member of the ionotropic group of glutamate receptors. These receptors are involved in a wide variety of processes in the central nervous system including synaptogenesis, synaptic plasticity, memory and learning. Erdosteine is a potent antioxidant and mucolytic agent. We aimed to investigate adverse effects of INH on rat hippocampal NMDAR receptors, and to elucidate whether erdosteine prevents possible adverse effects of INH. In the present study, compared to control group, NMDAR2A (NR2A) receptors were significantly decreased and malondialdehyde (MDA), end product of lipid peroxidation, production was significantly increased in INH-treated group. On the other hand, administration of erdosteine to INH-treated group significantly increased NR2A receptors and decreased MDA production. In conclusion, decreasing NR2A receptors in hippocampus and increasing lipid peroxidation correlates with the degree of oxidative effects of INH and erdosteine protects above effect of INH on NR2A receptors and membrane damage due to lipid peroxidation by its antioxidant properties. 相似文献
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