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J. L. Gardea-Torresdey K. J. Tiemann J. R. Peralta-Videa J. G. Parsons M. Delgado 《Microchemical Journal》2004,76(1-2):65
Traditional treatment methods used to clean-up heavy metal contamination of soils and waters are cost intensive whereas more cost effective methods need to be developed. The use of plant materials to remediate heavy contamination has been studied for the past two decades. This technique has shown much promise for many of the common heavy metal contaminants, but few studies have focused on the lanthanide series elements. By investigating the binding and interactions of the lanthanide elements to alfalfa biomass, a more complete understanding of the binding mechanisms and the interactions of heavy metals with biomaterials can be obtained. Different chemical functional groups on the alfalfa biomass, carboxyl, amino, sulfur, and ester groups, were modified to investigate the binding mechanisms of erbium(III) and holmium(III). Batch experiments were performed with native and chemically modified alfalfa biomass suggesting that the carboxyl groups play a major role in the binding of erbium(III) and holmium(III) to the alfalfa biomass. In addition, X-ray absorption spectroscopy (XAS) studies corroborated the data obtained from the batch experiments. 相似文献
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H. Bovensmann gen. Schröer E. Tiemann 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1994,31(1):67-73
In a strong laser field (I=2 GW/cm2) TlI is dissociated by a two-photon process and the Tl fragment is detected state specifically. The yield of Tl 6p 2 P 3/2 (Tl*) is measured as a function of the dissociation wavelength (480 nm–540 nm). If the dissociation wavelength is close to two-photon transitions of the Tl atom from 6p 2 P 3/2 to np2 P 1/2,3/2 or mf2 F 5/2,7/2,n=10 ... 15,m=7 ... 12 dips in the yield are observed. These dips show a significant asymmetric broadening, compared to a free atomic transition and the observation is interpreted as an absorption process of the transient state of dissociating TlI during the laser pulse. By applying the Landau-Zener approximation for the potential crossing of dressed molecular states, we are able to describe the broadening and the power density dependence of the observations. Simulations show that the asymmetry is determined by the difference potential of the electronic states which are coupled by the laser field. 相似文献
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Tahira Foyzun Abdullah Al Mahmud Md. Salim Ahammed Md. Imran Nur Manik Md. Kamrul Hasan KM Monirul Islam Simin Sobnom Lopa Md. Yusuf Al-Amin Kushal Biswas Mst. Rejina Afrin AHM Khurshid Alam Golam Sadik 《Molecules (Basel, Switzerland)》2022,27(3)
Neurotoxicity is a serious health problem of patients chronically exposed to arsenic. There is no specific treatment of this problem. Oxidative stress has been implicated in the pathological process of neurotoxicity. Polyphenolics have proven antioxidant activity, thereby offering protection against oxidative stress. In this study, we have isolated the polyphenolics from Acacia nilotica and investigated its effect against arsenic-induced neurotoxicity and oxidative stress in mice. Acacia nilotica polyphenolics prepared from column chromatography of the crude methanol extract using diaion resin contained a phenolic content of 452.185 ± 7.879 mg gallic acid equivalent/gm of sample and flavonoid content of 200.075 ± 0.755 mg catechin equivalent/gm of sample. The polyphenolics exhibited potent antioxidant activity with respect to free radical scavenging ability, total antioxidant activity and inhibition of lipid peroxidation. Administration of arsenic in mice showed a reduction of acetylcholinesterase activity in the brain which was counteracted by Acacia nilotica polyphenolics. Similarly, elevation of lipid peroxidation and depletion of glutathione in the brain of mice was effectively restored to normal level by Acacia nilotica polyphenolics. Gallic acid methyl ester, catechin and catechin-7-gallate were identified in the polyphenolics as the major active compounds. These results suggest that Acacia nilotica polyphenolics due to its strong antioxidant potential might be effective in the management of arsenic induced neurotoxicity. 相似文献
6.
O.?Docenko M.?Tamanis R.?FerberEmail author A.?Pashov H.?Kn?ckel E.?Tiemann 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2005,36(1):49-55
We present a detailed experimental study of the D1Π state of the
NaRb molecule by means of Fourier transform spectroscopy of laser induced
fluorescence. The entire data field for the D1Π state of Na85Rb
and Na87Rb consists of rovibrational levels with v′=0-39 and
J′=1-200. The data were incorporated into a direct fit of a
single potential energy curve to the level energies using the Inverted
Perturbation Approach method. The D1Π state q factors, which
describe the Λ-doubling, have been obtained in a wide range of
rotational and vibrational quantum numbers. Analysis revealed several
perturbation regions in the D1Π state.
Electronic supplementary material Online Material 相似文献
7.
The hyperfine structure of the (v'-v") = (27-0) band of the b(3)Pi(u0(+)) <-- X(1)Sigma(+)(g) transition has been observed by laser excitation spectroscopy in a highly collimated molecular beam. Hyperfine parameters for magnetic dipole and electric quadrupole interaction are derived from least-squares fitting of the hyperfine pattern and deperturbation between A(1)Sigma(+)(u) and b(3)Pi(u0(+)). Copyright 2000 Academic Press. 相似文献
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With a semiclassical model the measured energy and width of quasibound levels are described for theB 1Γ u state of Na2. A reliable complete potential function of this electronic state is derived including the potential hump which results from the competition between the electron exchange energy and the long range dipole-dipole interaction. The proposed computation of molecular potentials can be used in the general case and shows some advantages over RKR determinations. 相似文献