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71.
Amir H. Ahkami Michael Melzer Mohammad R. Ghaffari Stephan Pollmann Majid Ghorbani Javid Fahimeh Shahinnia Mohammad R. Hajirezaei Uwe Druege 《Planta》2013,238(3):499-517
To determine the contribution of polar auxin transport (PAT) to auxin accumulation and to adventitious root (AR) formation in the stem base of Petunia hybrida shoot tip cuttings, the level of indole-3-acetic acid (IAA) was monitored in non-treated cuttings and cuttings treated with the auxin transport blocker naphthylphthalamic acid (NPA) and was complemented with precise anatomical studies. The temporal course of carbohydrates, amino acids and activities of controlling enzymes was also investigated. Analysis of initial spatial IAA distribution in the cuttings revealed that approximately 40 and 10 % of the total IAA pool was present in the leaves and the stem base as rooting zone, respectively. A negative correlation existed between leaf size and IAA concentration. After excision of cuttings, IAA showed an early increase in the stem base with two peaks at 2 and 24 h post excision and, thereafter, a decline to low levels. This was mirrored by the expression pattern of the auxin-responsive GH3 gene. NPA treatment completely suppressed the 24-h peak of IAA and severely inhibited root formation. It also reduced activities of cell wall and vacuolar invertases in the early phase of AR formation and inhibited the rise of activities of glucose-6-phosphate dehydrogenase and phosphofructokinase during later stages. We propose a model in which spontaneous AR formation in Petunia cuttings is dependent on PAT and on the resulting 24-h peak of IAA in the rooting zone, where it induces early cellular events and also stimulates sink establishment. Subsequent root development stimulates glycolysis and the pentose phosphate pathway. 相似文献
72.
Mohammad Mahdi Najafpour Fahimeh Rahimi Davood Jafarian Sedigh Robert Carpentier Julian J. Eaton-Rye Jian-Ren Shen Suleyman I. Allakhverdiev 《Photosynthesis research》2013,117(1-3):423-429
In this report, gold or silver deposited on layered manganese oxide has been synthesized by a simple method and characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction spectrometry, atomic absorption spectroscopy, and energy-dispersive X-ray mapping. The gold deposited on layered manganese oxide showed efficient catalytic activity toward water oxidation in the presence of cerium(IV) ammonium nitrate. The properties associated with this compound suggest it is a functional model for the water-oxidizing complex in photosystem II. 相似文献
73.
Fahimeh Khodabandeh Mohamad Hassan Safaralizadeh Seyed Ali Safavi Shahram Aramideh 《Archives Of Phytopathology And Plant Protection》2013,46(5):610-614
Bacillus thuringiensis isolates were recovered from numerous sources including soil, grain dust, plant leaves, diseased insect larvae from insectariums and sericulture environments. B. thuringiensis strains were isolated using acetate selection method with 0.025?M. concentration. The morphology of crystals was studied using light microscopy. Bioassay tests were conducted on Ephestia kuehniella (Zeller) (L.) as well as Pieris brassicae (L.). Based on the results, 35 B. thuringiensis strains were isolated from 140 samples. Majority of strains (%31.42) had bipyramidal crystals. There was a significant difference in toxicity to insects among B. thuringiensis isolates; 28.57 and 14.28% of the isolates were toxic to the larvae of P. brassicae and E. kuehniella, respectively, causing more than 50% mortality. Results indicated that B. thuringiensis isolates with insecticidal activity could be used in integrated pest management to control farm and stored product pests. 相似文献
74.
Fahimeh Salimi Kai Zhuang Radhakrishnan Mahadevan Professor 《Biotechnology journal》2010,5(7):726-738
An alternative consolidated bioprocessing approach is the use of a co-culture containing cellulolytic and solventogenic clostridia. It has been demonstrated that the rate of cellulose utilization in the co-culture of Clostridium acetobutylicum and Clostridium cellulolyticum is improved compared to the mono-culture of C. cellulolyticum, suggesting the presence of syntrophy between these two species. However, the metabolic interactions in the co-culture are not well understood. To understand the metabolic interactions in the co-culture, we developed a genome-scale metabolic model of C. cellulolyticum comprising of 431 genes, 621 reactions, and 603 metabolites. The C. cellulolyticum model can successfully predict the chemostat growth and byproduct secretion with cellulose as the substrate. However, a growth arrest phenomenon, which occurs in batch cultures of C. cellulolyticum at cellulose concentrations higher than 6.7 g/L, cannot be predicted by dynamic flux balance analysis due to the lack of understanding of the underlying mechanism. These genome-scale metabolic models of the pure cultures have also been integrated using a community modeling framework to develop a dynamic model of metabolic interactions in the co-culture. Co-culture simulations suggest that cellobiose inhibition cannot be the main factor that is responsible for improved cellulose utilization relative to mono-culture of C. cellulolyticum. 相似文献
75.
Zohreh Sharifi Mahmood Mahmoodian Shooshtari Fahimeh Rangbar Kermani 《Indian journal of microbiology》2010,50(3):275-279
HCV infection is a leading cause of chronic liver disease, including cirrhosis of the liver. There are at least six major
genotypes and more than 50 subtypes of HCV. The prevalence and distribution of HCV genotypes depend on geographical location.
The aim of this study was to identify and compare the HCV genotypes in HCV infected blood donors and patients. In this cross-sectional
study, 167 serum samples from 103 blood donors and 64 patients with hepatitis C were investigated for HCV genotypes. HCV genotyping
was carried out using type-specific primers from the core region of the viral genome. The highest frequency was for genotype
1a, with 53 and 34 (51.5% versus 53.1%) of subjects in blood donors and patients respectively. Genotype 3a and 1b were the
other frequent genotypes with 4 and 16 (3.9% versus 25%) and 39 and 10 (37.9% versus 15.6%) subjects, respectively. There
was not any statistical significant association between the place of infection of the patients and genotype. The results of
this study indicate that the distribution of genotypes in the two populations was similar. The dominant HCV genotypes between
blood donors and patients were 1a, 3a and 1b respectively. 相似文献
76.
Alireza Khodavandi Fahimeh Alizadeh Farzad Aala Zamberi Sekawi Pei Pei Chong 《Mycopathologia》2010,169(4):287-295
Candidiasis is a term describing infections by yeasts from the genus Candida, and the type of infection encompassed by candidiasis ranges from superficial to systemic. Treatment of such infections often
requires antifungals such as the azoles, but increased use of these drugs has led to selection of yeasts with increased resistance
to these drugs. In this study, we used allicin, an allyl sulfur derivative of garlic, to demonstrate both its intrinsic antifungal
activity and its synergy with the azoles, in the treatment of these yeasts in vitro. In this study, the MIC50 and MIC90 of allicin alone against six Candida spp. ranged from 0.05 to 25 μg/ml. However, when allicin was used in combination with fluconazole or ketoconazole, the MICs
were decreased in some isolates. Our results demonstrated the existing synergistic effect between allicin and azoles in some
of the Candida spp. such as C. albicans, C. glabrata and C. tropicalis, but synergy was not demonstrated in the majority of Candida spp. tested. Nonetheless, In vivo testing needs to be performed to support these findings. 相似文献
77.
Haghi Ashtiani MT Rabbani A Mostafavi F Monajemzadeh M Ranjbar Kermani F Soltaninia J 《Biochemical genetics》2008,46(11-12):712-719
Congenital adrenal hyperplasia (CAH) is a group of potentially life-threatening disorders, most often caused by deficiency of steroid 21-hydroxylase. Children with ambiguous genitalia, hermaphroditism, or signs and symptoms of CAH admitted to Children's Medical Center were enrolled in the survey, and 101 patients were found. Karyotyping, clinical examination, and paraclinical tests were done. HLA typing was done in patients with proven classical CAH and their parents. HLA antigens were typed in children with CAH-type 21-hydroxylase deficiency. The antigen frequencies were compared with those of the control population. The studies revealed that two HLA antigens, HLA-B18 and HLA-B21, showed a significant increase in frequency. The calculated relative risk value was high, distinguishing the population of patients and their parents. The relative risk among patients was 11.82 for HLA-B18 and 1.75 for HLA-B21 antigens. There was no relationship between HLA-DR antigens and CAH. Studies on the correlation between HLA and CAH indicate an association with HLA-B18 and HLA-B21 antigens, and they can be used as genetic markers of the disorder in the Iranian population, if they are restricted to Iranian patients. 相似文献
78.
Identification of Staphylococcus aureus virulence genes in a murine model of bacteraemia using signature-tagged mutagenesis 总被引:13,自引:10,他引:3
Ji-Min Mei Fahimeh Nourbakhsh Charles W. Ford & David W. Holden 《Molecular microbiology》1997,26(2):399-407
Attaching and effacing (AE) bacteria are a diverse group of gastrointestinal pathogens, comprising members of four genera, that cause the intestinal epithelial microvilli to be replaced with raised clusters of filamentous actin that conform to the surface of attached bacteria. We have cloned a 35.4 kb 'pathogenicity island' from the prototype AE bacterium, enteropathogenic Escherichia coli , containing all previously described AE genes. Transfer of this pathogenicity island to avirulent E. coli converts the recipients into strains that secrete virulence proteins, induce host signal-transduction pathways, and cause AE lesions on cultured epithelial cells. These results demonstrate that this pathogenicity island contains all pathogen-specific genes necessary for inducing AE lesions, and that the defining feature of this class of pathogens can be acquired by an avirulent bacterium in a single genetic step. 相似文献
79.
80.
Crataegus coriifolia Sharifnia & Zarrinkolah is described as a new species from Iran. Its taxonomic relationships, ecology and distribution are discussed. An identification key to C. coriifolia and other two‐styled species of Crataegus occurring in Iran is provided. 相似文献