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81.
Zhao J Muhammad I Dunbar DC Mustafa J Khan IA 《Journal of agricultural and food chemistry》2005,53(3):690-693
Maca (Lepidium meyenii) has been used as a food in Peru for thousands of years. More recently a wide array of commercial maca products have gained popularity as dietary supplements, with claims of anabolic and aphrodisiac effects, although the biologically active principles are not fully known. In an earlier chemical investigation, two new alkamides and a novel fatty acid, as well as the N-hydroxypyridine derivative, macaridine, were isolated from L. meyenii. Further examination has led to the isolation of five additional new alkamides, namely, N-benzyl-9-oxo-12Z-octadecenamide (1), N-benzyl-9-oxo-12Z,15Z-octadecadienamide (2), N-benzyl-13-oxo-9E,11E-octadecadienamide (3), N-benzyl-15Z-tetracosenamide (4), and N-(m-methoxybenzyl)hexadecanamide (5). Their structures were established by spectrometric and spectroscopic methods including ESI-HRMS, EI-MS, (1)H, (13)C, and 2D NMR, as well as (1)H-(15)N 2D HMBC experiments. In addition, the identity of N-benzyl-15Z-tetracosenamide (4) was confirmed by synthesis. These compounds have been found from only L. meyenii and could be used as markers for authentication and standardization. 相似文献
82.
A split‐plot field trial was conducted to study the effect of foliar application of 0 kg/ha (control), 20 kg N/ha, 2 kg P/ha or 20 kg N + 2 kg P/ha at two basal levels, viz., 90 kg N + 40 kg P/ha (optimal dose) and 60 kg N + 27 kg P/ha (sub‐optimal dose). Each group received 50 kg K/ha, which was applied uniformly on the yield and quality of fennel. Spray was applied at the flowering stage, 120 days after sowing. The optimal basal dose gave better results than did the sub‐optimal one. Spray of 20 kg N + 2 kg P/ha proved optimum. This spray proved more effective at sub‐optimal than at optimal basal dose. The percentage of anethole (but not of fenchone) in the essential oil was significantly higher in plants grown with the sub‐optimal basal dose. Foliar application of N, P and N + P, on the other hand, decreased the anethole content of oil and increased that of fenchone significantly. Hence, foliar feeding may be recommended if the oil is required for perfumery and confectionary industries. 相似文献
83.
Gluten proteins from two cultivars of hard red spring (HRS) wheat with good and poor breadmaking quality were fractionated into 13 fractions by sequential extraction with dilute hydrochloric acid. Each subfraction was characterized by multistacking (MS) SDS‐PAGE under nonreducing conditions, followed by imaging densitometry. The glutenin polymers from the origins of MS‐SDS‐PAGE were analyzed by SDSP‐PAGE under reducing conditions to determine the composition of high and low molecular weight subunits. The results showed that fractions differed significantly in glutenin‐to‐gliadin ratios and in the size distribution of glutenin polymers. The earlier precipitated fractions were composed of more gliadins but fewer glutenin polymers. However, the glutenin polymers gradually increased in their relative quantities with the residue having the largest glutenin‐to‐gliadin ratio. The size distribution of glutenin polymers differed significantly from early precipitated to later fractions. The relative quantities of glutenin aggregates at the 4% origins increased significantly. The ratio of high molecular weight (HMW) to low molecular weight (LMW) glutenin subunits increased significantly from early to intermediate fractions. Between the two cultivars, significant differences were found in the ratio of HMW to LMW glutenin subunits and quantity of SDS insoluble glutenin polymers in the residue fraction with the better breadmaking quality cultivar ND706 having a greater ratio than the cultivar Sharp. It was concluded that the size distribution of glutenin polymers played an important role in determining the differences in breadmaking quality between the good and poor HRS wheat cultivars. 相似文献
84.
The use of capillary electrophoresis in SDS (SDS‐CE) for separation and quantification of HMW glutenin subunits (HMW‐GS) was investigated. HMW‐GS were precipitated with 40% acetone from 50% 1‐propanol extract of flour under reducing conditions after removal of monomeric proteins with 50% 1‐propanol. Poly (ethylene oxide) was used in the running buffer (3% w/v) for SDS‐CE. The results indicated that HMW‐GS could be well separated by SDS‐CE, including subunits 7+8, 7+9, 2+12, 5+10, and 17+18. However, HMW‐GS showed delayed migration times compared with molecular weight protein standards. Some HMW‐GS were reversed in their mobilities in SDS‐CE compared with their mobility and molecular weights by SDS‐PAGE. Therefore, the SDS‐CE was unsuitable for MW determination of HMW‐GS. A linear response was obtained from SDS‐CE of a plot of the concentration of HMW‐GS of the 40% acetone precipitate versus corrected areas for absorbance at 214 nm. Quantification of HMW‐GS for the two biotypes (subunits 5+10 vs. 2+12) of an Australian wheat cultivar Warigal confirmed the differences between the two biotypes in their quantity of HMW‐GS. Therefore, the technique could be used to quantify HMW‐GS in conjunction with SDS‐PAGE. 相似文献
85.
M. Zobayer Bin Mukhlish Maksudur Rahman Khan Mithun Chandra Bhoumick Sumona Paul 《Water, air, and soil pollution》2012,223(8):4949-4958
Batch sorption experiments were carried out to investigate the potentiality of papaya leaf powder (PLP) for the removal of methylene blue (MB) from aqueous solution. The effects of various experimental parameters, such as adsorbent dose, initial solution concentration, contact time, and solution pH were also studied. The amount of dye adsorbed was found to increase with increase in initial dye concentrations. Papaya leaf adsorbs MB better in basic medium. The adsorption equilibrium data fitted well in the Langmuir isotherm equation with a monolayer sorption capacity of 512.55?mg?g?1. The kinetics of MB adsorption onto papaya leaf was examined using the pseudo-first and pseudo-second order and unified approach kinetic models. The adsorption kinetics followed the pseudo-second order kinetic model, but the rate constant was found to depend on initial dye concentration. The unified approach model described the equilibrium and kinetics well. The forward and backward rate constants were determined from the unified approach model. 相似文献
86.
Faisal Khan Frieder Enzmann Michael Kersten Andreas Wiegmann Konrad Steiner 《Journal of Soils and Sediments》2012,12(1):86-96
Purpose
The purpose of this hydropedological work is to investigate the feasibility of a method to calculate permeability of soil peds on the matrix pore scale resolution. This paper focuses on imaging of the intra-aggregate microstructure and, based on the three-dimensional (3D) images, quantification of the pore network connectivity and permeability tensor. Finally, lattice Boltzmann equation (LBE) simulations of Navier–Stokes flow in the thus derived pore network allow to compute the heterogeneous 3D flow velocity field. 相似文献87.
P. N. Sivalingam D. K. Samadia Dhurendra Singh H. K. Changal Hanif Khan S. K. Sharma 《Genetic Resources and Crop Evolution》2011,58(7):1095-1103
Sixteen germplasm accessions of Prosopis cineraria with suitable horticultural traits were identified from north-western Rajasthan, India, propagated clonally by budding on
seedling rootstock and maintained in the field gene bank. Morphological characterization of seven-year-old trees of these
accessions by 21 traits indicated a lot of variation among the accessions tested. Higher number of flowers per raceme was
found in accession CIAH/K2, higher width of ripened pod in CIAH/K5, higher number of seeds per pod in CIAH/K12 and a higher
weight of seed per pod in CIAH/K6. Overall, CIAH/K16 was found to be a superior genotype for most of the useful traits. High
significant positive correlation was obtained with traits useful for horticultural values. Out of 62 random decamer primers
for random amplification (RAPD) reaction, and four minisatellite core sequence for direct amplification of minisatellite DNA
(DAMD) screened with these accessions, 12 RAPD and 2 DAMD primers were found polymorphic. Average polymorphism resolved by
these markers among the accessions was 93.2%. Genetic diversity revealed by Jaccard’s co-efficient was between 0.11 and 0.77,
and four major clusters were identified among these accessions by phylogenetic analysis using NTSYSpc-2.02e software. This
study shows the existence of high genetic diversity within these accessions. 相似文献
88.
Syed Mustafa Khizar Hussain Shah Abdul Naeem Muhammad Waseem Tauqeer Ahmad Sadullah Khan 《Water, air, and soil pollution》2011,217(1-4):57-65
Cr3+ sorption on strong acid exchanger Amberlyst-15(H+) is studied as a function of time and temperature using CrCl3.6H2O and [Cr4(SO4)5(OH)2] solutions. The rate is found to be governed by a mixed diffusion for both the solutions and faster for Cl1? solution than SO4 2?. The exchange capacities are found to be higher for Cl1? system than SO4 2?. From the rate constant values, the energies of activation are calculated using the well-known Arrhenius equation. Equilibrium data is explained with the help of the Langmuir equation. The Langmuir parameters are also found to be higher for exchange from the chloride solutions. Various thermodynamic parameters (??Ho, ??So, and ??Go) for Cr3+ exchange on the resin are calculated. The ??Go values are found to be negative while ??Ho and ??So are positive for both the Cr3+/Cl1? and Cr3+/SO4 2? systems. It is suggested that in case of Cl1? solutions, the metal is exchanged as Cr3+, while in case of SO4 2? solutions, the metal exchanging specie is CrSO4 +. 相似文献
89.
Comprehensive emission inventories for 2001 and 2004 for Kuwait’s main power stations located at Al-Doha and Al-Subyia have been prepared. These inventories are inserted, in conjunction with meteorological data, into the Source Complex model for Short Term Dispersion (ISCST4.5) to predict ambient ground level concentrations of sulphur dioxide (SO2) and nitrogen oxides (NOx) at selected receptors for years 2001 and 2004. The comparison of the results obtained for these 2 years show the influence of increase in emission rates due to urban and industrial growth. For model validation, computed results are compared with the measured daily average values of SO2 and NOx collected at a fixed Kuwait Environment Protection Agency air quality monitoring station located at the roof of polyclinic in Rabia. Individual contributions of each power station to the highest predicted values are assessed. The five highest hourly, daily and annual ground level concentration values under prevailing meteorological conditions are compared for 2001 and 2004. It is found that the hourly mean concentrations are strongly influenced by the prevailing meteorological conditions. The effect of meteorological conditions has not been that dominant for the daily and annual mean values and the predicted values for 2004 are higher than 2001, simply corresponding to a high emission rates, especially in summer months. Top 50 daily average values of SO2 show a slope of 0.806 for 2001 which means that the model predictions are 20% less than the observed levels. However, the predicted slope of SO2 for 2004 is 0.96 and the model predictions are in very close agreement with the observed data. 相似文献
90.
Rashid Iqbal Khan Ishfaq Ahmad Hafiz Touqeer Ahmad Ishaq Ahmed Abdul Ahad Qureshi 《Journal of plant nutrition》2013,36(18):2309-2319
The study was set up to evaluate the efficiency of amino acids and seaweed on vegetative growth, reproductive phase, yield, and postharvest storage quality of hydroponically grown bell pepper cultivars “Sven Rz F-1” and “Red Knight.” Different concentrations of amino acid and seaweed were sprayed on bell pepper plants under hydroponic conditions. Pre-harvest foliar application of amino acids and seaweed significantly increased plant height, number of leaves, leaf area, yield per plant, number of marketable fruits per plant, average fruit diameter, fruit wall thickness, and average single fruit weight. Amino acid and seaweed significantly improved postharvest physicochemical quality of both bell pepper cultivars under extended cold storage conditions. Conclusively, amino acid as well as seaweed extract not only improved growth, development, yield, and overall quality of bell pepper cultivars but also increased storage life with reduced weight loss and decay along with better physicochemical quality. 相似文献