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21.
Elements found in the edible parts of plants are considered to be the main source of nutrients for humans and animals. However, there is insufficient information on the relationship between heavy metal pollution in the growing soil of most edible plants. In this study, the distribution of elements in the edible forest nettle (Laportea alatipes) was evaluated as a function of geographical location. Forest land soils had higher concentrations of minor elements (Cu, Cr, Ni, and Zn) compared to soils from rural and suburban areas. Translocation factors for Cd and Pb showed effective translocation from the roots to the leaves; however, these heavy metals in leaves were still above South African maximum permissible levels for vegetables. Atmospheric depositions may play a significant role in higher Cd and Pb concentrations in the leaves. Bioaccumulation factors showed the plant to accumulate Cu, Mn, and Zn to meet physiological requirement levels. Geoaccumulation indices and enrichment factors showed no soil contamination or minimal enrichment by trace metals. Principal component analysis showed Co, Cr, Cu, Fe, Ni, Pb, and Zn in soil to originate from a common source which may be soil silicates and other minerals.  相似文献   
22.
Russian Journal of General Chemistry - The title compounds are synthesized by condensation of 2-[4-(arylidene)-5-oxo-4, 5-dihydrooxazol-2-yl]phenylacetate with aromatic amines in presence of the...  相似文献   
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24.
The reductive electrochemistry of substituted benzophenones in the aprotic room-temperature ionic liquid (RTIL) 1-butyl-1-methylpyrrolidinium bistriflimide occurs via two consecutive one-electron processes leading to the radical anion and dianion, respectively. The radical anion exhibited electrochemical reversibility at all time-scales whereas the dianion exhibited reversibility at potential sweep rates of >or=10 V s(-1), collectively indicating the absence of strong ion-paring with the RTIL cation. In contrast, reduction in 1-butyl-3-methylimidazolium bistriflimide is complicated by proton-transfer from the [Bmim] cation. At low potential sweep rates, reduction involves a single two-electron process characteristic of either an electrochemical, chemical, electrochemical (ECE) or disproportion-type (DISP1) mechanism. The rate of radical anion protonation in [Bmim] is governed by basicity and conforms to the Hammett free-energy relation. At higher potential sweep rates in [Bmim][NTf2], reduction occurs via two consecutive one-electron processes, giving rise to the partially reversible generation of the radical anion and the irreversible generation of the dianion, respectively. Also, the redox potentials for the reversible parent/radical anion couples were found to be a linear function of Hammett substituent constants in both RTIL media and exhibited effectively equivalent solvent-dependent reaction constants, which are similar to those for reduction in polar molecular solvents such as acetonitrile or alcohols.  相似文献   
25.
Herein, we report transition metal-catalyzed intramolecular cyclization of o-(1-alkynyl)benzenesulfonamides to afford 3-substituted benzothiazines regioselectively via a C-N bond forming reaction and Cu-catalyzed sequential C-N and C-C bond formation leading to the corresponding 3,4-disubstituted derivatives.  相似文献   
26.
The synthesis and spectroscopic characterization of ruthenium complexes(R-l to R-8) of the type[Ru(A)2(B)],(where A = 1,10-phenanthroline/2,2′-bipyridine and B = 3.4.5-tri-OCH3DPC,4-CH3-DPC,4-N-(CH32-DPC,4-NO2-DPC arc described. These ligands form bidentate octahedral ruthenium complexes.The title complexes were subjected to in vitro cytotoxic activity measurements against the human cancer T-lymphocyte cell lines MTT assay.In vitro evaluation of these ruthenium complexes revealed cytotoxic activity from 0.24 to 1.4μg/mL against CEM,0.44 to 1.9μg/mL against Molt4/C8.0.28 to 1.5μg/mL against L1210,0.24 to 0.98μg/mL against HL60,and 0.25 to 1.2μg/mL against BEL7402,depending the nature of the compound.  相似文献   
27.
Ultrasonic velocity, u density, ?? and viscosity, ?? of mixtures of N,N-dimethyl acetamide with equimolar mixture of ethanol?+?isopropyl alcohol/isobutyl alcohol/isoamyl alcohol, including those of pure liquids over the entire composition have been measured at T?=?308.15, 313.15, and 318.15?K. Using this data, various thermo-acoustic parameters such as deviations in ultrasonic velocity, ?u, isentropic compressibility, ?k s , viscosity, ????, excess molar volume, $ V_{\text{m}}^{\text{E}} $ and excess Gibb??s free energy of activation for viscous flow, ??G *E have been calculated at different temperatures. The calculated deviation and excess functions have been fitted to the Redlich?CKister type polynomial equation. The influence of temperature on the observed negative and positive values of deviation and excess thermodynamic properties has been explained in terms of molecular interactions present in the investigated acid?Cbase liquid mixtures. The experimental data of ultrasonic velocity have been used to check the applicability of velocity models of Nomoto, Van Dael and Vangeel and Junjie and viscosity data have also been availed to test the applicability of standard viscosity models of Grunberg-Nissan, Hind-Mc Laughlin, and Katti-Chaudhary for all the systems investigated at various temperatures.  相似文献   
28.
The ultrasonic velocities (u) and densities (??) for three binary mixture systems of 2-chloroaniline (CA) with ethyl acrylate (EA), butyl acrylate (BA), and 2-ethylhexyl acrylate (EHA) were measured over the entire mole fraction range at the temperature 308.15?K, including those of pure liquids. From these data, the deviations in ultrasonic velocity (??u), the excess molar volumes ( $V_{\mathrm{m}}^{\mathrm{E}}$ ), deviations in excess molar volume ( $\delta V_{\mathrm{m}}^{\mathrm{E}}$ ), deviations in isentropic compressibility (??k S), excess intermolecular free lengths ( $L_{\mathrm{f}}^{\mathrm{E}}$ ), and excess acoustic impedances (Z E) have been calculated. The variations of these properties with solution composition are discussed in terms of molecular interactions among unlike molecules of the mixtures. The excess and deviation functions have been fitted to Redlich-Kister type polynomials and the corresponding standard deviations ??(Y E) have been calculated. The deviations and excess values were plotted against the mole fraction of CA over the whole composition range. The $V_{\mathrm{m}}^{\mathrm{E}}$ and ??k S values are negative in the EA + CA and BA + CA systems but are positive in the EHA + CA system, which indicates the presence of specific interactions between unlike molecules. Further, theoretical values of the sound velocity in these mixtures have been evaluated using various theories and have been compared with experimental sound velocities to verify the applicability of such theories to the investigated systems. Two types of polynomial equations, f(x) and g(x), have been fitted to experimental values of ultrasonic velocities. The sound velocities obtained by these polynomials have extremely small deviations from the experimental values.  相似文献   
29.
Ceramides are known to be involved in various biological processes with their physiological levels elevated in various disease conditions such as diabetes, Alzheimer's, atherosclerosis. To facilitate the rapid screening of Cer d18:1/16:0, d18:1/24:0, d18:1/24:1, d18:1/18:0, d18:1/14:0, d18:1/20:0, and d18:1/22:0 inhibition in HepG2 cells, a RapidFire coupled to tandem mass spectrometry (RF–MS/MS) method has been developed. The RF platform provides an automated solid-phase extraction system that gave a throughput of 12.6 s per sample to an MS/MS system using electrospray ionization under the positive ion mode. Chromatographic separation of Cer d18:1/16:0, d18:1/24:0, d18:1/24:1, d18:1/18:0, d18:1/14:0, d18:1/20:0, and d18:1/22:0 was achieved using a ternary gradient on C8 type E cartridge. The MS/MS ion transitions monitored were 538.2 → 264.2, 650.7 → 264.2, 648.6 → 264.2, 566.4 → 264.2, 510.4 → 264.2, 594.4 → 264.2, 622.5 → 264.2, and 552.3 → 250.2 for Cer d18:1/16:0, d18:1/24:0, d18:1/24:1, d18:1/18:0, d18:1/14:0, d18:1/20:0, d18:1/22:0, and the internal standard (Cer d17:1/18:0), respectively. The RF–MS/MS methodology showed an excellent performance with an average Z′ value of 0.5–0.7. This is the first report of an RF–MS/MS assay for screening of ceramides which is amenable for high-throughput screening.  相似文献   
30.
The activity concentration of primordial radionuclides 226Ra, 232Th, and 40K in soil samples of Thirthahalli taluk were measured systematically by using a low background HPGe detector coupled to 16 K MCA. The measured activity concentration of 226Ra lies between 5.1?±?0.2 and 79.5?±?1.7 Bq kg?1with an average activity of 25.99 Bq kg?1, 232Th ranges from 5.1?±?0.3 to 95.3?±?2.2 Bq kg?1with an average activity of 33.60 Bq kg?1and that of 40K varies from 18.3?±?1.5 to 833.4?±?17.5 Bq kg?1with an average activity of 175.52 Bq kg?1. Higher concentration of these radionuclides were found in the soil samples where the regional geology is granites. The consequential gamma dose and the corresponding radiation hazard was also estimated and is found to be within the permissible limits. The possible radiological impact on the public was also determined and these results are presented in this paper.  相似文献   
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