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排序方式: 共有374条查询结果,搜索用时 15 毫秒
41.
42.
A. I. Youssef F. N. Nasr S. S. Stefanos S. S. A. Elkhair W. A. Shehata E. Agamy A. Herz S. A. Hassan 《Journal of Applied Entomology》2004,128(9-10):593-599
Abstract: Six insecticides (Malathion, Quik, Cidial, Dimethoate, Actellic, Deltamethrin) and two mineral oils (Super misrona and Kemesol) are currently used to control the most important pests in Mediterranean olive cultivation (olive fly, olive moth and black scale). Potential side-effects of these compounds were tested on the egg parasitoid Trichogramma cacoeciae Marchal, following recommendations of the working group 'Pesticides and Beneficial Organisms' of the International Organization for Biological Control, West Palaearctic Regional Section (IOBC/WPRS). In the present study, three different types of test methods were carried out: (1) initial toxicity dose–response test on adult wasps; (2) initial toxicity test on pupae, using field recommended rates; and (3) persistent test on olive foliage to assess the duration of harmful activity. The six insecticides tested reduced parasitism by 80–95% and rated as moderately harmful at the field recommended doses. The two mineral oils reduced parasitism up to 25% and were therefore rated as harmless to the adult stage of the parasitoid. The results of the pupal test (parasitoid pupa inside the host egg) showed that Malathion was harmless; Quik, Actellic and Cidial were slightly harmful, while Dimethoate and Deltamethrin were moderately harmful. The results of the persistence test on olive foliage showed that Malathion, Quik and Actellic were slightly persistent, while Cidial, Dimethoate and Deltamethrin were moderately persistent. 相似文献
43.
Various physiological processes of Ulva fasciata were investigated in the laboratory under light intensities of 1500, 2500 and 3500 lux respectively.It was shown that there is a strong correlation between light intensity and growth rate, which increased with the increase in light intensity up till 2500 lux. Light intensities above 3000 lux resulted in bleaching of the algal thalli.In no instance there was any discharge of swarmers in total darkness nor at very reduced light intensities of about 100 lux.Zoospores were always negatively phototactic, while gametes were positively phototactic, appearing always on the well-illuminated sides of the culture bottles.The maximum yield of total nitrogen, dry weight, and amino acid content coincides with the optimum light intensity. Under such conditions leucine, valine, -alanine and glutamic acids are found in abundance, while phenyl alanine, -aminobutyric and glycine are moderately represented.The amount of total fat content increases with the increse in light intensity up till 3500 lux. This might refer to a strong correlation between the rate of photosynthesis and the fat synthesis.It was found that fructose and raffinose were present in negligible amounts under reduced light intensities (1500 lux), while sucrose was found in rather higher quantities. The quantity of glucose is higher than that of fructose and raffinose but much less than that of sucrose under the same light intensity.Alexandria UniversityKuwait UniversityKuwait University 相似文献
44.
Inga M. Höben Rim Hjeij Heike Olbrich Gerard W. Dougherty Tabea Nöthe-Menchen Isabella Aprea Diana Frank Petra Pennekamp Bernd Dworniczak Julia Wallmeier Johanna Raidt Kim G. Nielsen Maria C. Philipsen Francesca Santamaria Laura Venditto Israel Amirav Huda Mussaffi Freerk Prenzel Heymut Omran 《American journal of human genetics》2018,102(5):973-984
45.
Ayman H. Jawadi Anwar Wakeel Waleed Tamimi Amre Nasr Zafar Iqbal Abdullah Mashhour Mohamed A. Fattah Nawaf Alkhanein Ahmad S. Abu Jaffal 《Journal of genetics》2018,97(4):925-930
Developmental dysplasia of the hip (DDH) is a congenital condition characterized by abnormality in acetabulum size and/or shape. The incidence rate of DDH differs between different populations with risk factors including positive family history, breech presentation, sex, firstborn status, side of the hip, mode of delivery and oligohydramnios. It is recognized that DDH has a genetic component that exhibit autosomal dominant patterns. Many candidate genes have been studied and found to be associated with the disease; most of them are normally involved in cartilage development and joint metabolism. In this study, the association of four single-nucleotide polymorphisms (SNPs) (rs731236, rs1544410, rs7975232 and rs2228570) in the vitamin D receptor (VDR) gene was studied by a case–control analysis. The study sample involves 50 cases with confirmed DDH presentation and 50 nonDDH controls. SNPs were genotyped using conventional polymerase chain reaction (PCR) and restriction fragment-length polymorphism (RFLP) techniques. Genotype and allele frequencies were analysed using SPSS software. No significant associations were found between the VDR polymorphisms analysed and DDH. Further work need to be performed using genomewide analysis to elucidate the genetic basis of DDH. 相似文献
46.
André Homeyer Patrik Nasr Christiane Engel Stergios Kechagias Peter Lundberg Mattias Ekstedt Henning Kost Nick Weiss Tim Palmer Horst Karl Hahn Darren Treanor Claes Lundström 《Diagnostic pathology》2017,12(1):80
Background
Steatosis is routinely assessed histologically in clinical practice and research. Automated image analysis can reduce the effort of quantifying steatosis. Since reproducibility is essential for practical use, we have evaluated different analysis methods in terms of their agreement with stereological point counting (SPC) performed by a hepatologist.Methods
The evaluation was based on a large and representative data set of 970 histological images from human patients with different liver diseases. Three of the evaluated methods were built on previously published approaches. One method incorporated a new approach to improve the robustness to image variability.Results
The new method showed the strongest agreement with the expert. At 20× resolution, it reproduced steatosis area fractions with a mean absolute error of 0.011 for absent or mild steatosis and 0.036 for moderate or severe steatosis. At 10× resolution, it was more accurate than and twice as fast as all other methods at 20× resolution. When compared with SPC performed by two additional human observers, its error was substantially lower than one and only slightly above the other observer.Conclusions
The results suggest that the new method can be a suitable automated replacement for SPC. Before further improvements can be verified, it is necessary to thoroughly assess the variability of SPC between human observers.47.
Oversulfated chondroitin sulfate is a contaminant in heparin associated with adverse clinical events
Guerrini M Beccati D Shriver Z Naggi A Viswanathan K Bisio A Capila I Lansing JC Guglieri S Fraser B Al-Hakim A Gunay NS Zhang Z Robinson L Buhse L Nasr M Woodcock J Langer R Venkataraman G Linhardt RJ Casu B Torri G Sasisekharan R 《Nature biotechnology》2008,26(6):669-675
Recently, certain lots of heparin have been associated with an acute, rapid onset of serious side effects indicative of an allergic-type reaction. To identify potential causes for this sudden rise in side effects, we examined lots of heparin that correlated with adverse events using orthogonal high-resolution analytical techniques. Through detailed structural analysis, the contaminant was found to contain a disaccharide repeat unit of glucuronic acid linked beta1-->3 to a beta-N-acetylgalactosamine. The disaccharide unit has an unusual sulfation pattern and is sulfated at the 2-O and 3-O positions of the glucuronic acid as well as at the 4-O and 6-O positions of the galactosamine. Given the nature of this contaminant, traditional screening tests cannot differentiate between affected and unaffected lots. Our analysis suggests effective screening methods that can be used to determine whether or not heparin lots contain the contaminant reported here. 相似文献
48.
Schmidt FH Hüben M Gider B Renault F Teulade-Fichou MP Weinhold E 《Bioorganic & medicinal chemistry》2008,16(1):40-48
Plasmid DNA (pUC19 and pBR322) was sequence-specifically, covalently labelled with Cy3 fluorophores using a newly synthesised N-adenosylaziridine cofactor and the DNA methyltransferase M.TaqI. The fluorescently labelled plasmids were used for transfection of mammalian cells and their intracellular distribution was visualised by epifluorescence and confocal fluorescence microscopy. Although these prokaryotic plasmids do not contain nuclear import sequences, translocation into the nuclei was observed. 相似文献
49.
Cyclooxygenase-2 (Cox-2) is a key enzyme in the conversion of arachidonic acid to prostaglandins that has been shown to have
a particular importance in the progression of several malignancies including nasopharyngeal carcinoma (NPC). In the current
report, we designed a case-controlled study to evaluate the susceptibility and prognostic implications of the functional −765
G > C genetic variation in NPC. A PCR and restriction fragment length polymorphism analysis was used to determine the polymorphism
in a Tunisian population of patients with NPC (n = 180) and in healthy control subjects (n = 169). A higher risk for NPC was observed for carriers of COX-2 −765 C allele (OR = 1.76; P = 0.01). This association remains significant after adjustments for age and sex (OR = 1.89; P = 0.008). Regarding prognostic indicators, a significant association was found between −765 C allele carriers and the presence
of lymph node metastasis (OR = 2.28; P = 0.01), as well as, with tumor stage (OR = 2.73; P = 0.03). This is the first report on the studies of COX-2 SNPs in NPC and our data suggest that this genetic variant may
play a role in mediating susceptibility to NPC, as well as, in neoplastic progression, a finding which further supports the
involvement of COX-2 in NPC etiology.
Hela Ben Nasr and Karim Chahed contributed equally to the study. 相似文献
50.
There is accumulating evidence that excitotoxicity and oxidative stress resulting from excessive activation of glutamate (N-methyl-d-aspartate) NMDA receptors are major participants in striatal degeneration associated with 3-nitropropionic acid (3NP) administration.
Although excitotoxic and oxidative mechanisms are implicated in 3NP toxicity, there are conflicting reports as to whether
NMDA receptor antagonists attenuate or exacerbate the 3NP-induced neurodegeneration. In the present study, we investigated
the involvement of NMDA receptors in striatal degeneration, protein oxidation and motor impairment following systemic 3NP
administration. We examined whether NMDA receptor antagonists, memantine and ifenprodil, influence the neurotoxicity of 3NP.
The development of striatal lesion and protein oxidation following 3NP administration is delayed by memantine but not affected
by ifenprodil. However, in behavioral experiments, memantine failed to improve and ifenprodil exacerbated the motor deficits
associated with 3NP toxicity. Together, these findings suggest caution in the application of NMDA receptor antagonists as
a neuroprotective agent in neurodegenerative disorders associated with metabolic impairment. 相似文献