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81.
Aswini Panigrahi Julius Benicky Renhuizi Wei Jaeil Ahn Radoslav Goldman Miloslav Sanda 《Molecules (Basel, Switzerland)》2022,27(7)
Development of high throughput robust methods is a prerequisite for a successful clinical use of LC-MS/MS assays. In earlier studies, we reported that nLC-MS/MS measurement of the O-glycoforms of HPX is an indicator of liver fibrosis. In this study, we show that a microflow LC-MS/MS method using a single column setup for capture of the analytes, desalting, fast gradient elution, and on-line mass spectrometry measurements, is robust, substantially faster, and even more sensitive than our nLC setup. We demonstrate applicability of the workflow on the quantification of the O-HPX glycoforms in unfractionated serum samples of control and liver disease patients. The assay requires microliter volumes of serum samples, and the platform is amenable to one hundred sample injections per day, providing a valuable tool for biomarker validation and screening studies. 相似文献
82.
V. Ragupathi M. Safiq P. Panigrahi T. Hussain S. Raman R. Ahuja G. S. Nagarajan 《Ionics》2017,23(7):1645-1653
LiMnBO3 has been identified as a promising cathode material for next-generation lithium-ion batteries. In this study, LiMnBO3 along with glassy lithium borate material (LiMnBO3 (II)) is synthesized by sol-gel method. X-ray diffraction (XRD) analysis depicts the existence of LiBO2 glassy phase along with m-LiMnBO3 phase. Transmission electron microscopy (TEM) analysis confirms the presence of LiBO2 glassy phase. An enhanced electrical conductivity of 3.64 × 10?7 S/cm is observed for LiMnBO3 (II). The LiBO2 glassy phase is found to promote the Li reaction kinetics in LiMnBO3 (II). The synthesized LiMnBO3 (II) delivers a first discharge capacity of 310 mAh g?1 within a potential window of 1.5–4.5 V at C/10 rate. Further, a discharge capacity of 186 mAh g?1 at the 27th cycle shows a better cycle performance. The enhanced capacity is due to the presence of LiBO2 glassy phase and more than one Li-ion transfer in the lithium-rich stoichiometry of LiMnBO3 (II). Density functional theory calculation reveals the exact electronic structure of m-LiMnBO3 with a band gap of 3.05 eV. A charge transfer mechanism is predicted for delithiation process of m-LiMnBO3. 相似文献
83.
84.
Corrections to results of electric field gradient (EFG) already published [Pramana — J. Phys.41, 443 (1993)] are reported. The corrected net EFG is:q=−8.01×1013 esu/cm3 against the published valueq=16.06×1013 esu/cm3. The present result agrees reasonably well with the experimental result, |q
expt|=13×1013 esu/cm3.
Recently, a computational error is detected, which modifies the results of EFG, we have already published [1]. The error was
committed mainly in the part that evaluated thep-p contribution [1] to EFG by the conduction electrons. The corrected results are summarized in table 1 which must replace the
table 1 of the published work [1].
In addition, the lattice parameters as well as the temperature were also misquoted in the previous work [1]. The right parameters
are:a=6.25311 au andc=9.96509 au. The temperature at which EFG’s are calculated is 293 K instead of 11 K as reported before [1].
The discussions and conclusions made in the published work [1] remain almost unchanged except that they now refer to the corrected
numbers. Although the corrected net EFG suffers a sign reversal from the one already published [1], the agreement with experiment
is still considered reasonably good because the sign of experimental EFG is not determined. The computational error however
does not affect the introduction and theory section of the published work [1]. 相似文献
85.
Rate of oxidation of acetophenones by Ce(IV) in aqueous acetic acid 80:20 (v/v) either slows down or remains constant over a range of cetyltrimethyl ammonium bromide (CTAB) concentration exceeding the cmc value. The rate is then found to increase sharply as the surfactant concentration increases with no sign of reaching a maximum or constant value. From Fluorescence quenching, binding constant for p-nitro acetophenone has been evaluated. The rate data have been rationalized on the basis of a reaction between the acetophenones situated on the micelle surface and active Ce(IV) species in the bulk aqueous phase. 相似文献
86.
Aliphatic amino acids are smoothly oxidized by peroxomonophosphoric acid (PMPA) in the pH region 6–10. Kinetic studies reveal second order dependence in the amino acid not observed hitherto in any of the PMPA oxidations. Dependence in PMPA is unity. Rate-pH profile yields a maximum around pH 8. The reaction path includes oxidation steps due to H2PO5? and HPO52?. Second order dependence in the amino acid has been attributed to participation of two Zwitter-ionic molecules of the amino acid to form a nucleophile. 相似文献
87.
The kinetics of oxidation of sodium thiosulphate by potassiumbis(tellurato) cuprate(III) in an alkaline medium has been reported. The reaction is first order in [S2O
3
2−
] but zero order in copper(III). Hydroxide ions are found to retard the oxidation rate. A rate expression rationalising the
kinetic data has been derived. Sodium tetrathionate has been found to be the product of oxidation. 相似文献
88.
Panigrahi BS 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2000,(7):1337-1344
Fluorescence enhancement of Tb3+ has been studied, using substituted benzoic acids as ligands. These ligands enhance the fluorescence of Tb3+ by about three orders of magnitude. The enhancement is observed due to ligand sensitized fluorescence. The fluorescence of Tb3+ in these complexes is synergistically enhanced by the addition of trioctylphosphine oxide (TOPO) in Triton X-100. The synergism displayed by TOPO was observed only when Triton X-100 micellar medium was used. TOPO dissolved in SDS/DTAB micellar medium did not result in synergistic fluorescence enhancement of Tb3+. These observations are discussed in detail and the synergism displayed by TOPO is rationalized on the basis of the structure of the surfactants. 相似文献
89.
Dhara S Chandra S Magudapathy P Kalavathi S Panigrahi BK Nair KG Sastry VS Hsu CW Wu CT Chen KH Chen LC 《The Journal of chemical physics》2004,121(24):12595-12599
Photoluminescence study using the 325 nm He-Cd excitation is reported for the Au nanoclusters embedded in SiO(2) matrix. Au clusters are grown by ion beam mixing with 100 KeV Ar(+) irradiation on Au [40 nm]/SiO(2) at various fluences and subsequent annealing at high temperature. The blue bands above approximately 3 eV match closely with reported values for colloidal Au nanoclusters and supported Au nanoislands. Radiative recombination of sp electrons above Fermi level to occupied d-band holes are assigned for observed luminescence peaks. Peaks at 3.1 and 3.4 eV are correlated to energy gaps at the X- and L-symmetry points, respectively, with possible involvement of relaxation mechanism. The blueshift of peak positions at 3.4 eV with decreasing cluster size is reported to be due to the compressive strain in small clusters. A first principle calculation based on density functional theory using the full potential linear augmented plane wave plus local orbitals formalism with generalized gradient approximation for the exchange correlation energy is used to estimate the band gaps at the X- and L-symmetry points by calculating the band structures and joint density of states for different strain values in order to explain the blueshift of approximately 0.1 eV with decreasing cluster size around L-symmetry point. 相似文献
90.
Indian Reduced Activation Ferritic Martensitic steel is implanted with 130 keV helium ions to a fluence of 5 × 1014 and 1 × 1016 ions/cm2 and investigated using positron annihilation spectroscopy. The samples were characterised by defect sensitive S and W-parameters using depth resolved slow positron beam. A dose dependency is observed in the nucleation and growth of helium bubbles with annealing temperature. An experimental evidence for the migration of smaller helium-vacancy complexes is observed via the variation in thickness/width of irradiated layer with temperature. The S–W plot clearly shows the regions corresponding to defect annealing, bubble nucleation and growth. 相似文献