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61.
Elsayed E. Hafez Gamal M. Abdel-Fattah Safwat A. El-Haddad Younes M. Rashad 《Annals of microbiology》2013,63(3):1195-1203
A time course study was conducted to investigate disease development and molecular defense response in common bean (Phaseolus vulgaris L.) plants colonized by a mixture of five arbuscular mycorrhizal (AM) fungi, namely, Glomus mosseae, G. intraradices, G. clarum, Gigaspora gigantea, and Gigaspora margarita, and post-infected with the soil-borne pathogen Rhizoctonia solani. Results showed that pre-colonization of bean plants by AM fungi significantly reduced disease severity and disease incidence. DNA fingerprinting using the differential display technique revealed a genetic polymorphism (86.8 %) in bean plants that resulted from the colonization by AM fungi. Two genetic mechanisms were recorded: (1) switching on of new genes and (2) induction of other active genes, including the defense genes chitinase and β-1,3-glucanase, to a highly expressed state. 相似文献
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Plasmonics - This research demonstrates a high-performance temperature sensor based on the one-dimensional photonic crystal. The main idea of our sensing procedure is essentially depending on the... 相似文献
64.
The present work explores the possibility of formulating an oral insulin delivery system using nanoparticulate complexes made
from the interaction between biodegradable, natural polymer called chitosan and anionic surfactant called sodium lauryl sulfate
(SLS). The interaction between chitosan and SLS was confirmed by Fourier transform infrared spectroscopy. The nanoparticles
were prepared by simple gelation method under aqueous-based conditions. The nanoparticles were stable in simulated gastric
fluids and could protect the encapsulated insulin from the GIT enzymes. Additionally, the in vivo results clearly indicated that the insulin-loaded nanoparticles could effectively reduce the blood glucose level in a diabetic
rat model. However, additional formulation modifications are required to improve insulin oral bioavailability. 相似文献
65.
Two polyploid hybrids between cassava (Manihot esculenta) cultivar 307-2 and its wild relatives M. glaziovii and M. anomala, were studied to examine the relationship between ploidy level and the production of seeds without fertilization. A clearing method was applied to assess ovule sizes as an indication of multiembryony. The diploid cultivar 307-2 had regular 18 bivalents at meiotic metaphase 1 while the polyploid types showed chromosome configurations varying from 3 to 4 quadrivalents and 28 to 30 bivalents. A total of 14% of studied ovules of the polyploid hybrid involving M. glaziovii were multiebryonic, while the percentage of multiembryony was as low as 2% in the polyploid hybrid M. anomala×M. esculenta. Diploid hybrid types did not show any multi embryony. Adventitious embryos were found and documented for the first time in polyploid hybrids M. esculenta×M. glaziovii. The association of multiple embryo formation with ovary size and pollination showed that apomictic embryos form independently from fertilization. Simple iodized carmine stain for measuring pollen viability proved as efficient as the sophisticated Alexander method. 相似文献
66.
Elgamacy MA Shalaby RA Elkodsh AT Kamel AF Elsayed MS Abou-El-Ella DA 《Bioinformation》2011,7(2):52-58
We are reporting the discovery of small molecule inhibitors for vascular endothelial growth factor receptor type 2 (VEGFR-2) extracellular domain. The VEGFR-2 extracellular domain is responsible for the homo-dimerization process, which has been recently reported as a main step in VEGFR signal transduction cascade. This cascade is essential for the vascularization and survival of most types of cancers. Two main design strategies were used; Molecular docking-based Virtual Screening and Fragment Based Design (FBD). A virtual library of drug like compounds was screened using a cascade of docking techniques in order to discover an inhibitor that binds to this new binding site. Rapid docking methodology was used first to filter the large number of compounds followed by more accurate and slow ones. Fragment based molecular design was adopted afterwards due to unsatisfactory results of screening process. Screening and design process resulted in a group of inhibitors with superior binding energies exceeding that of the natural substrate. Molecular dynamics simulation was used to test the stability of binding of these inhibitors and finally the drug ability of these compounds was assisted using Lipinski rule of five. By this way the designed compounds have shown to possess high pharmacologic potential as novel anticancer agents. 相似文献
67.
For the past six decades, parasitic sea lampreys (Petromyzon marinus) have caused devastating losses to salmonid fisheries in the Great Lakes. To reduce the number of sea lampreys, the Great Lakes Fishery Commission began a large-scale program based on trapping male sea lampreys, sterilizing them, and releasing sterile males back into streams to compete with fertile males for spawning females. The transfer of lampreys among lakes can potentially lead to the transfer of various pathogens, and this has raised major concerns regarding the possibility of resident fish populations becoming infected by introduced pathogens. During a health inspection of sea lampreys collected from Lake Ontario, lampreys with obvious furuncle-like lesions (1-2 cm in diameter) were noticed. Most of the furuncles occupied the dorso-lateral musculature, and Aeromonas salmonicida subsp. salmonicida was isolated from the kidneys. This bacterium was cultured from kidneys of 2.5% of the sea lampreys collected from two locations within the Lake Ontario watershed in 2004. The identity of bacterial colonies was presumptively verified with biochemical reactions and confirmed with polymerase chain reaction. This is the first report of A. salmonicida infection in sea lamprey in the Great Lakes basin associated with furunculosis. 相似文献
68.
Phoma herbarum has been associated with two outbreaks of systemic mycosis in hatchery-reared chinook salmon (Oncorhynchus tshawytscha) fingerlings. Affected fish exhibited abnormal swimming behavior, exophthalmia, multiple rounded areas of muscle softening,
protruded hemorrhagic vents, and abdominal swelling. In all affected fish, swimbladders were filled with whitish creamy viscous
fungal mass, surrounded by dark red areas in swimbladder walls, kidneys, and musculature. Clinical and histopathological examinations
suggest that the infection may have started primarily in the swimbladder and then spread to the kidneys, gastrointestinal
tract, and surrounding musculature. Consistent microscopical findings included broad septate branched fungal hyaline hyphae,
5–12 μm in diameter within the swimbladder, stomach, and often within and adjacent to blood vessels. Profuse growths of woolly
brown fungal colonies were obtained from swimbladders and kidneys on Sabouraud medium. On corn meal agar the formation of
pycnidia, characteristic of Phoma spp., was detected within 10 days of incubation. Morphological and molecular analyses identified this fungus as Phoma herbarum. This report underscores systemic fungal infections as a threat to raceway-raised salmon. 相似文献
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Elsayed Mansour Ana M. Casas M. Pilar Gracia José Luis Molina-Cano Marian Moralejo Luigi Cattivelli William T. B. Thomas Ernesto Igartua 《Molecular breeding : new strategies in plant improvement》2014,33(2):249-265
Advances in plant breeding through marker-assisted selection (MAS) are only possible when genes or quantitative trait loci (QTLs) can contribute to the improvement of elite germplasm. A population of recombinant inbred lines (RILs) was developed for one of the best crosses of the Spanish National Barley Breeding Program, between two six-row winter barley cultivars Orria and Plaisant. The objective of this study was to identify favourable QTLs for agronomic traits in this population, which may help to optimise breeding strategies for these and other elite materials for the Mediterranean region. A genetic linkage map was developed for 217 RILs, using 382 single nucleotide polymorphism markers, selected from the barley oligonucleotide pool assay BOPA1 and two genes. A subset of 112 RILs was evaluated for several agronomic traits over a period of 2 years at three locations, Lleida and Zaragoza (Spain) and Fiorenzuola d’Arda (Italy), for a total of five field trials. An important segregation distortion occurred during population development in the region surrounding the VrnH1 locus. A QTL for grain yield and length of growth cycle was also found at this locus, apparently linked to a differential response of the VrnH1 alleles to temperature. A total of 33 QTLs was detected, most of them for important breeding targets such as plant height and thousand-grain weight. QTL × environment interactions were prevalent for most of the QTLs detected, although most interactions were of a quantitative nature. Therefore, QTLs suitable for MAS for most traits were identified. 相似文献