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Scientometrics
Authors:
Yan Wang
,
Yishan Wu
,
Yuntao Pan
,
Zheng Ma
, and
Ronald Rousseau
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Quantitative analysis of oxyresveratrol in different parts of Morus species by HPTLC and HPLC is described. The methods were validated for selectivity, extraction efficiency, sensitivity, accuracy, and intra-day and inter-day reproducibility. Extraction efficiency was in the range 100 ± 3.2%. Limits of detection and quantification for oxyresveratrol in plant samples were 50 and 200 ng per band, respectively, by HPTLC and 0.3 and 1.0 μg mL−1, respectively, by HPLC. The amount of oxyresveratrol was higher in stems than in leaves. It was not detected in leaves of Morus rubra L, and was detected only in roots and bark of Morus alba L. These methods, which were found to be simple and sensitive with good precision and reproducibility, were also used for analysis of oxyresveratrol in other related species and genera.

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A high-performance thin-layer chromatographic (HPTLC) method was developed for the quantification of two anthocyanins, viz., cyanidin-3-O-rutinoside and cyanidin-3-O-glucoside, from the berries of Euterpe oleracea Mart., commonly referred to as “acai” and dietary supplements claiming to contain acai. The extraction efficiency of anthocyanins from acai fruit pulp using acidified methanol was optimized using sonication techniques. Chromatographic separation of the selected anthocyanins was achieved with silica gel 60F254 HPTLC plates using ethyl acetate-formic acid-acetic acid-water (10:1.1:1.1:2.6 ν/ν) as the mobile phase. Quantification of anthocyanins was carried out using a densitometric reflection/absorption mode at 520 nm. Polynomial calibration curves were plotted for the concentration range of 100–500 ng spot−1 for both compounds and produced good correlation coefficients >0.99. The method was validated for precision, accuracy, and repeatability. The method’s accuracy was evaluated by a recovery study conducted at two different concentrations. The average recovery was found to be 100 to 102%. The specificity of the method was confirmed using retention factor (R F) and spectral correlation.

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The thermal decomposition process of the complex [Cu(NBOCTB)][Cu(NO3)4] H2O has been studied by TG and DTG technique, and possible intermediates of the thermal decomposition have also been conjectured from the TG and DTG curves. The results suggest that the decomposition of the complex involves five steps:

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Abstract  

In the present study, two novel 99mTc nitrido dithiocarbamate complexes containing heterocyclic linkage, the bis(N-2-(1-piperidyl)ethyl dithiocarbamato) nitrido technetium-99m complex 99mTcN(PPEDTC)2 and bis(N-2-(1-pyrrolidino)ethyl dithiocarbamato) nitrido technetium-99m complex 99mTcN(PREDTC)2 have been synthesized by the reduction of 99mTcO4 into [99mTcN]2+ with stannous chloride in the presence of succinic dihydrazide and propylenediamine tetraacetic acid, followed by the addition of the corresponding dithiocarbamate ligands. The radiochemical purity of the complexes were over 90% as measured by thin layer chromatography (TLC). In vitro studies showed that the complexes possessed good stability. Their partition coefficients indicated that they were lipophilic complexes. Biodistribution in mice showed that the 99mTcN(PPEDTC)2 complex accumulated in brain with high uptake and good retention. As compared with the 99mTcN(PREDTC)2 complex, the former showed much higher brain uptake than the latter.

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Genetic structure of 142 parent lines of sorghum [Sorghum bicolor (L.) Moench] was analyzed using model-based approach based on SSR markers. Forty-one selected from 103 SSR markers were used to analyze the parent lines, which generated 189 alleles revealed by each marker ranging from 2 to 11 with an average of 4.6 per marker. The polymorphic information content (PIC) value was 0.543 with a range of 0.089 to 0.850. All the parent lines were assigned to 7 subgroups, named Kafir, Kaoliang, Feterita, Shallu, Hegari, Milo and Durra. Parent lines without clear pedigree record were clustered into their corresponding groups, and genetic components of each line were estimated by Q-values. Information of this study would be useful for breeders to conclude their genetic background and select appropriate parents for germplasm improvement and hybrid breeding, and thus improve the efficiency of breeding programs.

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Abstract  

The kinetics of the reductive stripping of plutonium(IV) by dihydroxyurea (DHU) in 30% TBP/kerosene-HNO3 system was studied with a constant interfacial area cell. The stripping rate of plutonium(IV) increases with the increase of the stirring speed of two phases and the interfacial area. The activation energy of this process is 28.4 kJ/mol. Under the given experimental conditions, the mass transfer of Pu is not controlled by redox reaction, but controlled by molecular diffusion from the organic phase to organic film layer and from the aqueous film layer to aqueous phase. The rate equation of reductive stripping (process is controlled by diffusion) was obtained as: r 0 = k′[Pu(IV)]0[DHU]a 0.16[HNO3]a −0.34. The rate constant k′ is (5.0±0.4)·10−2 (mol/L)0.18·min−1 at 18.0°C.

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Abstract  

Using a LKB-2277 bioactivity monitor, stop-flow mode, the power–time curves of Candida albicans growth at 37 °C affected by berberine were measured. The check experiments were studied based on agar cup method to observe the inhibitory diameter and serial dilution method to determine the minimal inhibitory concentration (MIC) of berberine on C. albicans growth. By analyzing the quantitative thermogenic parameters taken from the power–time curves using correspondence analysis (CA), we could find that berberine at a low concentration (5.0 μg mL−1) began to inhibit the growth of C. albicans and at a high concentration (75.0 μg mL−1) completely inhibited C. albicans growth. The anti-fungal activity of berberine could also be expressed as half-inhibitory concentration IC50, i.e., 50% effective in this inhibition. The value of IC50 of berberine on C. albicans was 34.52 μg mL−1. The inhibitory diameters all exceeded 10 mm in test range and the MIC was 500 μg mL−1. Berberine had strong anti-fungal effect on C. albicans growth. This work provided an important idea of the combination of microcalorimetry and CA for the study on anti-fungal effect of berberine and other compounds. Compared with the agar cup method and serial dilution method, microcalorimetry not only offered a useful way for evaluating the bioactivity of drugs, but also provides more information about the microbial growth and all this information was significant for the synthesis and searching of antibiotics.

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Abstract  

Kinetic studies of stripping of Np(IV) from 30% Tri-Butyl-Phosphate/Odourless Kerosene (TBP/OK) into a nitric acid solution containing acetohydroxamic acid (CH3CONHOH) have been investigated using a Lewis cell. The different parameters affecting the back-extraction rate of Np(IV) such as Np, TBP, nitric acid, nitrate, acetohydroxamic acid(AHA) concentration in addition to temperature, stirring speed and special interfacial area were separately studied and a rate equation was deduced. Results have been compared among themselves and other published works on similar systems. Mechanisms of stripping processes have been proposed.

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Abstract  

The kinetics of back-extraction of Pu(IV) from 30% Tri-Butyl-Phosphate/Odourless Kerosene (TBP/OK) into a nitric acid solution containing N,N-dimethylhydroxylamine (DMHAN) have been investigated using a Lewis cell. The different parameters affecting the back-extraction rate of Pu(IV) such as plutonium, nitric acid, DMHAN concentration in addition to temperature, stirring speed were separately studied and a rate equation was deduced. The activation energy of this process is 28.4 kJ/mol.

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