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21.
There is a high diversity among cultivated walnut trees in Iran due to its long time of seed propagation and vast area of cultivation. In this study some morphological characters as well as Simple Sequence Repeat (SSRs) markers were used to analyze the genetic diversity and relationships among 31 Iranian walnut genotypes along with four foreign cultivars. The nut weight ranged from 7.52 to 17.73 g, kernel weight from 4.00 to 9.83 g, and kernel percentage ratio from 38.78 to 67.05% among studied genotypes. In SSRs analysis, nine primer pairs were tested that produced 39 alleles ranging from 2 to 8, with a mean value of 5.10 allele per primer. The Iranian genotypes showed relatively high diversity both for their SSRs loci and morphological traits. Although the foreign cultivars (‘Serr’, ‘Vina’, ‘Franquette’ and ‘Lara’) clustered with each other, they also laid close and within the Iranian genotype. The results of the study provided us with valuable diversity among our genotypes which could be used for breeding studies and also showed the power of genetic markers for analysis and evaluation of this diversity.  相似文献   
22.
Production of superabsorbent polymers from cotton and viscose waste textiles was investigated. The cellulose wastes were carboxymethylated, crosslinked by divinylsulfone, and then converted to superabsorbent material using air-drying, freeze-drying, or air-drying after phase inversion. The separation of cellulose from synthetic polymers in the textile (polyester) was carried out by direct dissolution of cellulose in N-methylmorpholine-N-oxide (NMMO), or separation by dissolution in water after carboxymethylation of the textiles. The progress of the carboxymethylation reaction was evaluated by measurement of the degree of substitution (DS) of carboxymethyl cellulose (CMC). The DS values of 0.50–0.86 confirmed the prosperous substitution of hydrophilic carboxymethyl groups into the cellulosic chains. The water binding capacity and the swelling rate of the superabsorbents prepared under different conditions were measured. Under the best condition the superabsorbent obtained from waste textiles showed an ultimate water binding capacity of 541 g/g which was notably higher than that of the reference superabsorbent derived from cotton linter (470 g/g). The amount of absorbed water by this product exceeded that of the reference sample after 60 min immersion.  相似文献   
23.

Background:

Cutaneous leishmaniasis is one of the most important parasitic diseases in humans. In this disease, one of the responsible organisms is Leishmania major, which is transmitted by sandfly vector. There are specific differences in biochemical profiles and metabolite pathways in logarithmic and stationary phases of Leishmania parasites. In the present study, 1H NMR spectroscopy was used to examine the metabolites outliers in the logarithmic and stationary phases of promastigotes in L. major to enlighten more about the transmission mechanism in metacyclogenesis of L. major.

Methods:

Promastigote was cultured, logarithmic and stationary phases were separated by the peanut agglutinin, and cell metabolites were extracted. 1H NMR spectroscopy was applied, and outliers were analyzed using principal component analysis.

Results:

The most altered metabolites in stationary and logarithmic phases were limited to citraconic acid, isopropylmalic acid, L-leucine, ornithine, caprylic acid, capric acid, and acetic acid.

Conclusion:

1H NMR spectroscopy could play an important role in the characterization of metabolites in biochemical pathways during a metacyclogenesis process. These metabolites and their pathways can help in exploiting a transmission mechanism in metacyclogenesis, and outcoming data might be used in the metabolic network reconstruction of L. major modeling. Key Words: Leishmania major, Metabolomics, Principal component analysis  相似文献   
24.
In order to shed light on the role of Iran in apple evolution and domestication, we chose to investigate the relationships of a collection of 159 accessions of wild and domesticated apples including Iranian indigenous apple cultivars and landraces, selected wild species, and old apple scion and rootstock cultivars from different parts of the world. The majority of the wild species belonged to M. sieversii, which is widely believed to be the main maternal wild ancestor of domestic apples, from Kazakhstan and M. orientalis, which is one of the probable minor ancestors of domestic apples, from Turkey and Russia located on the east and west of Iran, respectively. The accessions were assigned into six arbitrary populations for the purpose of generating information on genetic parameters. Nine simple sequence repeat (SSR) loci selected from previous studies in apple were screened over DNA extracted from all the accessions. Results showed that all SSR loci displayed a very high degree of polymorphism with 11–25 alleles per locus. In total, there were 153 alleles across all loci with an average of 17 alleles per locus. The SSR allelic data were then used for estimation of population genetic parameters, including genetic variation statistics, F-statistics, gene flow, genetic identity, genetic distance and then cluster analysis using POPGENE 1.32 software. The F-statistics and gene flow in particular, showed that there was more intra-population than between population variation. The genetic identity and genetic distance estimates, and the dendrogram generated from the un-weighted pair group arithmetic average (UPGMA) method of cluster analysis showed that the Iranian cultivars and landraces were more closely related to M. sieversii from Central Asia (east of Iran) and M. orientalis native to Turkey and Russia than to other accessions of Malus species. Also, the old apple cultivars from different parts of the world have a closer genetic relationship to M. sieversii, M. orientalis and the Iranian apples, than to other wild species. Based on these results, we suggest that the Iranian apples may occupy an intermediate position between the domesticated varieties and wild species. We propose that Iran could be one of the major players in apples’ domestication and transfer from Central Asia to the western countries.  相似文献   
25.
Mother corm size is the most important factor for production of replacement corms, flower, and stigma yield in saffron. In semi-arid regions, water shortage is a deterrent agent for appropriate corm growth of saffron. Therefore, in this experiment the effects of six levels of superabsorbent polymer (SAP) including 0, 10, 20, 30, 40, and 50 kg ha-1 was investigated on growth indices of replacement corms of saffron. For this purpose, an experiment was evaluated at the research farm of the Saffron Research Group, Sarayan Faculty of Agriculture, University of Birjand, Iran, during 2013-2015. Results showed that SAP application did not considerable effect on corm growth indices in the first life cycle of saffron. Nevertheless, consumption of 30-40 kg ha-1 SAP somewhat improved the number and total weight of replacement corms per clone. In the second life cycle of saffron, the positive impact of SAP was clearly observed on the growth of replacement corms. The application of 40 kg ha-1 SAP increased the amount of number of replacement corms per clone by 13%, total weight of replacement corms per clone by 36%, and scale weight of corms per clone by 50% compared with control. In addition, the amount of mean weight of replacement corms and mean number of buds per corm in treatment of application of 40 kg ha-1 SAP were 29 and 27% higher than the control treatment, respectively. SAP application decreased the amount of non-standard (< 8 g) corm production while significantly increased the percentage of corms with standard weight. Overall, the increasing effect of SAP application on corm weight, bud number, and standard corm yield was higher than the number of produced corms per clone. In addition, water-use efficiency in SAP application treatments (6.1 kg standard corm m-3) was more than the control (4.34 kg m-3) treatment. In total, SAP application is an appropriate strategy for production of standard saffron corms in semi-arid regions.  相似文献   
26.
Determination of glucosamine and N-acetyl glucosamine in fungal cell walls   总被引:1,自引:0,他引:1  
A new method was developed to determine glucosamine (GlcN) and N-acetyl glucosamine (GlcNAc) in materials containing chitin and chitosan, such as fungal cell walls. It is based on two steps of hydrolysis with (i) concentrated sulfuric acid at low temperature and (ii) dilute sulfuric acid at high temperature, followed by one-step degradation with nitrous acid. In this process, chitin and chitosan are converted into anhydromannose and acetic acid. Anhydromannose represents the sum of GlcN and GlcNAc, whereas acetic acid is a marker for GlcNAc only. The method showed recovery of 90.1% of chitin and 85.7-92.4% of chitosan from commercial preparations. Furthermore, alkali insoluble material (AIM) from biomass of three strains of zygomycetes, Rhizopus oryzae, Mucor indicus, and Rhizomucor pusillus, was analyzed by this method. The glucosamine contents of AIM from R. oryzae and M. indicus were almost constant (41.7 +/- 2.2% and 42.0 +/- 1.7%, respectively), while in R. pusillus, it decreased from 40.0 to 30.0% during cultivation from 1 to 6 days. The GlcNAc content of AIM from R. oryzae and R. pusillus increased from 24.9 to 31.0% and from 36.3 to 50.8%, respectively, in 6 days, while it remained almost constant during the cultivation of M. indicus (23.5 +/- 0.8%).  相似文献   
27.
28.
Ovulation rate and litter size are important reproduction traits in sheep and are of high economic value. Reproduction traits typically have low to medium heritabilities and do not exhibit a noticeable response to phenotypic selection. Therefore, inclusion of genetic information of the genes associated with reproductive ability could efficiently enhance the selection response. The most important major genes affecting prolificacy and their genetic diversities in different sheep breeds were reviewed. Different causative mutations with major effects on reproductive traits including ovulation rate and litter size have been found in various sheep breeds around the world. A general overview of the studies on main prolificacy genes showed that some alleles may express different phenotypic effects in different breeds, and thus, further studies on epistatic effects are necessary for more understanding of genetic control of reproductivity in sheep. Regarding the polygenic control of fertility traits, application of new high‐throughput technologies to find new variants is essential for future studies. Moreover, genomewide association studies and genomic best linear unbiased predictions of breeding values are likely to be effective tools for genetic improvement of sheep reproductive performance traits.  相似文献   
29.
The purpose of this study was to evaluate the levels of Zinc, Copper, Iron and Copper/Zinc ratio in the serum of adult patients with pulmonary tuberculosis in Iran. Serum levels of Zinc and Copper were determined by flame atomic absorption spectrophotometer and scrum iron concentration was measured by using an Auto Analyzer. The study group consisted of 50 pulmonary tuberculosis patients before treatment and after 6 months of anti-tubercular therapy. Levels of scrum Zn (p < 0.001) and Fe (p < 0.001) in TB patients were significantly increased after 6 months of anti-tubercular therapy. However, serum Cu concentration (p < 0.01) and Cu/Zn ratio (p < 0.05) were decreased after 6 months of anti-tubercular therapy. Some studies indicated a strong association of Zn, Cu, Fe and the Cu/Zn ratio with TB. In this study, we found remarkable change in Cu/Zn ratio. Some researchers mentioned that serum Cu/Zn ratio could be used as an important laboratory marker for diagnosis and treatment of tuberculosis. They also mentioned that trace element levels must be closely monitored during the process of disease.  相似文献   
30.
Background:One of the main challenges with conventional scaffold fabrication methods is the inability to control scaffold architecture. Recently, scaffolds with controlled shape and architecture have been fabricated using 3D-printing. Herein, we aimed to determine whether the much tighter control of microstructure of 3DP PLGA/β-TCP scaffolds is more effective in promoting osteogenesis than porous scaffolds produced by solvent casting/porogen leaching. Methods:Physical and mechanical properties of porous and 3DP scaffolds were studied. The response of pre-osteoblasts to the scaffolds was analyzed after 14 days. Results:The 3DP scaffolds had a smoother surface (Ra: 22 ± 3 µm) relative to the highly rough surface of porous scaffolds (Ra: 110 ± 15 µm). Water contact angle was 112 ± 4° on porous and 76 ± 6° on 3DP scaffolds. Porous and 3DP scaffolds had the pore size of 408 ± 90 and 315 ± 17 µm and porosity of 85 ± 5% and 39 ± 7%, respectively. Compressive strength of 3DP scaffolds (4.0 ± 0.3 MPa) was higher than porous scaffolds (1.7 ± 0.2 MPa). Collagenous matrix deposition was similar on both scaffolds. Cells proliferated from day 1 to day 14 by fourfold in porous and by 3.8-fold in 3DP scaffolds. ALP activity was 21-fold higher in 3DP scaffolds than porous scaffolds. Conclusion:The 3DP scaffolds show enhanced mechanical properties and ALP activity compared to porous scaffolds in vitro, suggesting that 3DP PLGA/β-TCP scaffolds are possibly more favorable for bone formation. Key Words: Alkaline phosphatase, β-tricalcium phosphate, Poly(lactic-co-glycolic) acid copolymer  相似文献   
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