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51.
Sabra Khorsand Ahmadi Maryam Mahmoodian Moghadam Parisa Mokaberi Mohammad Reza Saberi 《Journal of biomolecular structure & dynamics》2013,31(9):1880-1898
The interaction between bovin β-Lactoglobulin (β-LG) and retinol at two different pH values was investigated by multispectroscopic, zeta potential, molecular modeling, and conductometry measurements. The steady state and polarization fluorescence spectroscopy revealed that complex formation at two different pH values could occur through a remarkable static quenching. According to fluorescence quenching, one set of binding site at pH 2 and two sets of binding sites at pH 7 were introduced for binding of retinol to β-LG that show the enhancement of saturation score of β-LG to retinol in dimmer condition. The polarization fluorescence analysis represented that there is more affinity between β-LG and retinol at pH 7 rather than at pH 2. The effect of retinol on β-LG was studied by UV-visible, circular dichroism (CD), and synchronous fluorescence, which indicated that retinol induced more structural changes on β-LG at pH 7. β-LG–retinol complex formation at two different pH values was recorded via applying resonance light scattering (RLS) and zeta potential. Conductometry and RLS showed two different behaviors of interaction between β-LG and retinol at two different pH values; therefore, dimmer formation played important roles in different behaviors of interaction between β-LG and retinol. The zeta potential was the implied combination of electrostatic and hydrophobic forces which are involved in β-LG–retinol complex at two different pH values, and the hydrophobic interactions play a dominant role in complex formation. Molecular modeling was approved by all experimental results. The acquired results suggested that monomer and dimmer states of β-LG can be induced by retinol with different behaviors. 相似文献
52.
A Moroccan Houbara Bustard pedigree was analyzed to evaluate the genetic variability in captive breeding population using genealogical approaches. The whole Houbara breeding flock (WP) for the period 1993–2004 was made up of 531 birds comprising 346 females and 185 males. The reference population (RP) comprised 198 individuals ready for reproduction from 2000 to 2004 cohorts. The corresponding percentage of known ancestors was estimated as 98.23% for the parent generation, 41.19% for the grandparent generation and 7.00% for the great grandparents generation. The average generation interval for Houbara was computed as 4.64 years. Genetic variability loss per generation was ascertained using the effective population size (), the founder genome equivalent (fge), the effective number of ancestors and founders (fa) and (fe), respectively, for the RP and across each cohort. The results showed no bottleneck events in the breed but some loss of genetic variability just after the initiation of the conservation program. However, the annual effective population size based on the realized increase in inbreeding () was estimated to be 207 for the RP and 1,000 for the WP. With regard to conservation breeding schemes, the genealogical evidence presented here is very useful as it revealed the positive effect of migration on Houbara breeding. The mating strategies will assist in the future control and management of the genetic variability of this population. Zoo Biol. 32:366‐373, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
53.
Nimra Akram Naheed Khan Mehreen Ameen Shahmeera Mahmood Komal Shamim Marium Amin 《Chronobiology international》2013,30(9):1262-1268
ABSTRACTSeveral studies have focused on determining the effect of chronotype and learning approach on academic achievement separately indicating that morning types have an academic advantage over the evening types and so have the deep learners over the surface learners. But, surprisingly none have assessed the possible relationship between chronotype and learning approach. So, the current study aimed to evaluate this association and their individual influence on academic performance as indicated by the Cumulative Grade Point Average (CGPA) as well as the effect of their interaction on academic performance. The study included 345 undergraduate medical students who responded to reduced Morningness-Eveningness Questionnaire and Biggs Revised Two-Factor Study Process Questionnaire. Morning types indulged in deep learning while evening types in surface learning. Morning and evening types did not differ on academic performance but deep learners had better academic outcomes than their counterparts. The interaction between chronotype and learning approach was significant on determining academic achievement. Our findings gave the impression that chronotype could have an impact on academic performance not directly but indirectly through learning approaches. 相似文献
54.
Hossein Jafari Mansoorian Amir Hossein Mahvi Ahmad Jonidi Jafari Mohammad Mehdi Amin Ahmad Rajabizadeh Narges Khanjani 《Enzyme and microbial technology》2013,52(6-7):352-357
Electricity generation from microbial fuel cells which treat food processing wastewater was investigated in this study. Anaerobic anode and aerobic cathode chambers were separated by a proton exchange membrane in a two-compartment MFC reactor. Buffer solutions and food industry wastewater were used as electrolytes in the anode and cathode chambers, respectively. The produced voltage and current intensity were measured using a digital multimeter. Effluents from the anode compartment were tested for COD, BOD5, NH3, P, TSS, VSS, SO4 and alkalinity. The maximum current density and power production were measured 527 mA/m2 and 230 mW/m2 in the anode area, respectively, at operation organic loading (OLR) of 0.364 g COD/l.d. At OLR of 0.182 g COD/l.d, maximum voltage and columbic efficiency production were recorded 0.475 V and 21%, respectively. Maximum removal efficiency of COD, BOD5, NH3, P, TSS, VSS, SO4 and alkalinity were 86, 79, 73, 18, 68, 62, 30 and 58%, respectively. The results indicated that catalysts and mediator-less microbial fuel cells (CAML-MFC) can be considered as a better choice for simple and complete energy conversion from the wastewater of such industries and also this could be considered as a new method to offset wastewater treatment plant operating costs. 相似文献
55.
Hassan Ahmadi Gavlighi Anne S. Meyer J. Dalgaard Mikkelsen 《Biotechnology letters》2013,35(2):205-212
Product inhibition by cellobiose decreases the rate of enzymatic cellulose degradation. The optimal reaction conditions for two Emericella (Aspergillus) nidulans-derived cellobiohydrolases I and II produced in Pichia pastoris were identified as CBHI: 52 °C, pH 4.5–6.5, and CBHII: 46 °C, pH 4.8. The optimum in a mixture of the two was 50 °C, pH 4.9. An almost fourfold increase in enzymatic hydrolysis yield was achieved with intermittent product removal of cellobiose with membrane filtration (2 kDa cut-off): The conversion of cotton cellulose after 72 h was ~19 % by weight, whereas the conversion in the parallel batch reaction was only ~5 % by weight. Also, a synergistic effect, achieving ~27 % substrate conversion, was obtained by addition of endo-1,4-β-d-glucanase. The synergistic effect was only obtained with product removal. By using pure, monoactive enzymes, the work illustrates the profound gains achievable by intermittent product removal during cellulose hydrolysis. 相似文献
56.
Maryam Pakfetrat Jamshid Roozbeh Shahroodi Ali Asgar Zolgadr Hasan Amin Larie Mohamad Hosein Nikoo Leila Malekmakan 《Biological trace element research》2013,153(1-3):11-15
Increased homocysteine (hCys) level is an independent risk factor for cardiovascular complications in end-stage renal disease (ESRD) patients. The aim of this study was to evaluate effect of zinc (Zn) supplement on serum hCys level in ESRD patients. One hundred ESRD patients with Zn deficiency were enrolled in this double-blind randomized clinical trial. They were randomly subdivided into two groups and supplemented with Zn (Zn group) or placebo (control group) for 6 weeks. Fasting plasma hCys and Zn levels were measured before and at 43rd days after the start of the study. Serum Zn levels increased significantly (p?<?0.0001), in Zn-treated group in comparison to placebo-treated group. In the Zn-treated group, serum hCys levels reduced significantly (p?<?0.0001), compared to placebo group (p?>?0.05). There was a significant (p?<?0.0001) reduction of mean percentage of hCys in Zn-treated group compared to the placebo group. Our study showed that Zn supplementation decreases serum hCys levels in ESRD patients with Zn deficiency. 相似文献
57.
Ismail Eş Maycon Carvalho Ribeiro Samuel Rodrigues dos Santos Júnior Amin Mousavi Khaneghah Armando Garcia Rodriguez André Corrêa Amaral 《Bioprocess and biosystems engineering》2016,39(10):1487-1500
The whole-cell immobilization on chitosan matrix was evaluated. Bacillus sp., as producer of CGTase, was grown in solid-state and batch cultivation using three types of starches (cassava, potato and cornstarch). Biomass growth and substrate consumption were assessed by flow cytometry and modified phenol–sulfuric acid assays, respectively. Qualitative analysis of CGTase production was determined by colorless area formation on solid culture containing phenolphthalein. Scanning electron microscopy (SEM) analysis demonstrated that bacterial cells were immobilized on chitosan matrix efficiently. Free cells reached very high numbers during batch culture while immobilized cells maintained initial inoculum concentration. The maximum enzyme activity achieved by free cells was 58.15 U ml?1 (36 h), 47.50 U ml?1 (36 h) and 68.36 U ml?1 (36 h) on cassava, potato and cornstarch, respectively. CGTase activities for immobilized cells were 82.15 U ml?1 (18 h) on cassava, 79.17 U ml?1 (12 h) on potato and 55.37 U ml?1 (in 6 h and max 77.75 U ml?1 in 36 h) on cornstarch. Application of immobilization technique increased CGTase activity significantly. The immobilized cells produced CGTase with higher activity in a shorter fermentation time comparing to free cells. 相似文献
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Zev A. Binder Kelli M. Wilson Vafi Salmasi Brent A. Orr Charles G. Eberhart I-Mei Siu Michael Lim Jon D. Weingart Alfredo Quinones-Hinojosa Chetan Bettegowda Amin B. Kassam Alessandro Olivi Henry Brem Gregory J. Riggins Gary L. Gallia 《PloS one》2016,11(3)