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One myrsinol-type diterpene ester (1) isolated from Euphorbia decipiens was evaluated for analgesic activity in the acetic acid induced writhing test in mice. Different dose (5-20 mg/kg i.p.) of the compound showed significant antinociceptive activity, which was comparable to standard analgesic drugs, aspirin and ibuprofen (100 mg/kg i.p.).  相似文献   
3.
Genetic Resources and Crop Evolution - Cicer arietinum L. (chickpea) is one of the most significant legume crops domesticated in the Fertile Crescent. This study was aimed to characterize a diverse...  相似文献   
4.
A 2-step chromatographic separation, using both thin layer chromatography (TLC) and high pressure liquid chromatography (HPLC), in conjunction with the high sensitivity of laser fluorometry permits extension of the detection limits of aflatoxin contamination in corn to 0.1 ppb (microgram/kg) with a 26% root mean square variation. Aflatoxin B1 is extracted from corn with water-methanol and cleaned up by TLC. The recovery of aflatoxin from the TLC plates was linear from 10 to 1000 pg. Aflatoxin B1 is converted to the more highly fluorescent B2A derivative by treatment with 1N HCl. Experiments with aflatoxin B1 standard establish a constant conversion to B2A over approximately 3 orders of magnitude in B1 concentration. An extract of the B2A aflatoxin derivative is injected onto a reverse phase HPLC column. A flowing droplet of eluant is irradiated by an amplitude-modulated 325 nm He-Cd ion laser beam, and fluorescence from the droplet is detected by a lock-in amplifier in phase with the laser modulation. Several chromatograms are presented that demonstrate the capability of this procedure for removing interfering components in the corn extract.  相似文献   
5.
Abstract. The Olsen method is an indicator of plant-available phosphorus (P). The effect of time and temperature on residual phosphate in soils was measured using the Olsen method in a pot experiment. Four soils were investigated: two from Pakistan and one each from England (calcareous) and Colombia (acidic). Two levels of residual phosphate were developed in each soil after addition of phosphate by incubation at either 10 °C or 45 °C. The amount of phosphate added was based on the P maximum of each soil, calculated using the Langmuir equation. Ryegrass was used as the test crop. The pooled data for the four soils incubated at 10 °C showed good correlation between Olsen P and dry matter yield or P uptake ( r 2= 0.85 and 0.77, respectively), whereas at 45 °C, each soil had its own relationship and pooled data did not show correlation of Olsen P with dry matter yield or P uptake. When the data at both temperatures were pooled, Olsen P was a good indicator of yield and uptake for the English soil. For the Pakistani soils, Olsen P after 45 °C treatment was an underestimate relative to the 10 °C data and for the Colombian soil it was an overestimate. The reasons for these differences need to be explored further before high temperature incubation can be used to simulate long-term changes in the field.  相似文献   
6.
Recent advances in sequencing technology have brought several novel platforms for marker development and subsequent genotyping. The high-throughput and cost effective marker techniques have changed the entire scenario of marker applications. The huge genotypic data obtained with next generation sequencing (NGS) also demands analytical tools, statistical advances, and comprehensive understanding to cope with breeding applications. In the present review, we discussed different available marker techniques, their strengths, and limitations. Emphasis was given on software tools, analytical pipelines, workbenches, and online resources available for marker development. Comparison of SNP genotyping involving complexity reduction techniques like GBS, RRL, RAD, and array-based platforms were presented in a view to describe suitability for specific purposes. We found that genotyping by whole genome re-sequencing has great potential, and could be a routine application in the near future with continuously decreasing cost of sequencing. Microsatellites, still a valuable option for breeders, have also advanced with NGS. Here a catalogue of tools for microsatellite evaluation in short sequence reads was provided. The most common applications of molecular marker like QTL mapping, genome-wide association mapping (GWAS), and genomic selection were highlighted. The present review will be helpful for the effective utilization of available resources and for the planning of crop improvement programs employing molecular marker techniques.  相似文献   
7.
A nonlinear optical spectroscopy based on degenerate four-wave mixing has made possible direct measurements of species temperature and concentration profiles through the boundary layer of a reactive plasma at atmospheric pressure. Spectra were obtained for CH and C(2) radicals over a range of conditions including those for the plasma chemical vapor deposition of diamond films. Numerical simulations based on a one-dimensional stagnation-point flow model are in good agreement with the measurements. The CH mole fraction is shown to rise and fall as a function of distance from the substrate, which is compelling experimental evidence for the complex chemistry that is occurring in the plasma boundary layer.  相似文献   
8.
Proteins from human cerebrospinal fluid: binding with nucleic acids   总被引:3,自引:0,他引:3  
Cerebrospinal fluid (CSF) contains two groups of proteins that bind tightly to DNA and to polyriboguanylic acid, respectively. In certain diseases the amounts of a given nucleic acid bound by a constant volume of CSF may increase, while in others the amount of such proteins may be reduced. Binding of polyriboguanylic acid increased in CSF samples from patients with brain tumors, stroke, multiple sclerosis, and communicating hydrocephalus, but it significantly decreased in CSF samples from patients with obstructive hydrocephalus. These increases may or may not be proportional to the rise in total CSF proteins characteristic for these diseases. Elevated binding of DNA was observed in samples from patients with hydrocephalus, epilepsy, and cortical atrophy. The technique described may be applicable to the diagnosis of a variety of diseases of the central nervous system.  相似文献   
9.
The distribution of polycyclic aromatic hydrocarbons(PAHs) in the Allende meteorite has been probed with two-step laser desorption/laser multiphoton ionization mass spectrometry. This method allows direct in situ analysis with a spatial resolution of 1 square millimeter or better of selected organic molecules. Spectra from freshly fractured interior surfaces of the meteorite show that PAH concentrations are locally high compared to the average concentrations found by wet chemical analysis of pulverized samples. The data suggest that the PAHs are primarily associated with the fine-grained matrix, where the organic polymer occurs. In addition, highly substituted PAH skeletons were observed. Interiors of individual chondrules were devoid of PAHs at our detection limit(about 0.05 parts per million).  相似文献   
10.
Individual phospholipid vesicles, 1 to 5 micrometers in diameter, containing a single reagent or a complete reaction system, were immobilized with an infrared laser optical trap or by adhesion to modified borosilicate glass surfaces. Chemical transformations were initiated either by electroporation or by electrofusion, in each case through application of a short (10-microsecond), intense (20 to 50 kilovolts per centimeter) electric pulse delivered across ultramicroelectrodes. Product formation was monitored by far-field laser fluorescence microscopy. The ultrasmall characteristic of this reaction volume led to rapid diffusional mixing that permits the study of fast chemical kinetics. This technique is also well suited for the study of reaction dynamics of biological molecules within lipid-enclosed nanoenvironments that mimic cell membranes.  相似文献   
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