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71.
A strategy for the simultaneous detection of multiple microRNA (miRNA) targets was developed utilizing fluorophore/quencher-labeled oligonucleotide probe sets. Two miRNA targets (miR-155 and miR-103), whose misregulation has afforded them status as putative biomarkers in certain types of cancer, were detected using our assay design. In the absence of target, the complementary fluorophore-probe and quencher-probe hybridize, resulting in a fluorescence resonance energy transfer-based quenching of the fluorescence signal. In the presence of unlabeled target, however, the antisense quencher-probe can hybridize with the target, resulting in increased fluorescence intensity as the quencher-probe is sequestered beyond the Förster radius of the fluorescent-probe. The assay design was tested in multiple matrices of buffer, cellular extract, and serum; and detection limits were found to be matrix-dependent, ranging from 0.34 to 8.89 pmol (3.4–59.3 nM) for miR-155 and 2.90–11.8 pmol (19.3–79.0 nM) for miR-103. Single, double, and triple nucleotide selectivity was also tested. Additionally, miR-155 concentrations were assessed in serum samples obtained directly from breast cancer patients without the need for RNA extraction. This assay is quantitative, possesses a low detection limit, can be applied in multiple complex matrices, and can obtain single-nucleotide selectivity. This method can be employed for the multiplex detection of solution-phase DNA or RNA targets and, more specifically, for the direct detection of serum miRNA biomarkers. 相似文献
72.
An organoselenium-based NSe(3) type of tripodal system 2 as a Hg(2+)-selective fluorescence "turn-on" probe is described. The "turn-on" fluorescence behavior of this selenotripod 2 is significant because it depends on Hg-Se bond formation and acts as a reporting unit for this system. The system exhibits immediate response (15 s) with a subnanomolar detection limit (0.1 nM) for the Hg(2+) ion. It efficiently detects both aqueous and nonaqueous Hg(2+) at 2 nM concentration. 相似文献
73.
A simple mechanism of replica symmetry breaking for spin-glass, as suggested by Parisi, has been used to solve the anisotropic
spin-glass model of Sherrington and Ghatak. Temperature variation of the correlation parameters and the resulting variations
with the temperature of the thermodynamic quantities like internal energy, specific heat and entropy have been evaluated.
It is found that the anisotropy has considerable effect on the properties of the spin system. At low temperatures, the specific
heat varies asT
2. However, the entropy is positive for temperatures above 0.1°K, which is a considerable improvement on the results of Sherrington
and Ghatak. The results are expected to be in good agreement with experiment or computer simulation studies near transition
temperatures. 相似文献
74.
Jacques kagan Katrina Tadema-Wielandt Ging Chan Som N. Dhawan Jeffrey Jaworsky Indra Prakash Sudershan K. Arora 《Photochemistry and photobiology》1984,39(4):465-467
Abstract— Phenylheptatriyne (PHT) is a good singlet oxygen sensitizer in vitro. In vivo , its phototoxicity toward E. coli B has been proved unequivocally to depend on the presence of oxygen. The literature reports indicating that phenylheptatriyne was representative of a new class of sensitizers were probably based on experiments conducted under conditions which were not strictly anaerobic. 相似文献
75.
P. Singha Deo V. A. Schweigert F. M. Peeters A. K. Geim 《Physica E: Low-dimensional Systems and Nanostructures》1998,1(1-4)
The Ginzburg–Landau equations coupled with the three-dimensional Maxwell equations are solved for the disc geometry in order to explain recent magnetization experiments. In order to explain the experimental results on a 0.5
m radius Al disc, we have to assume that the superconducting state stays in the lowest angular momentum giant-vortex state even in regions where it is not the lowest energy state. 相似文献
76.
Vimal Chandra Srivastava Indra Deo Mall Indra Mani Mishra 《Colloids and surfaces. A, Physicochemical and engineering aspects》2008,312(2-3):172-184
The present study reports the competitive adsorptive removal of cadmium (Cd(II)) and zinc (Zn(II)) ions from binary systems using rice husk ash (RHA), a waste obtained from the rice husk-fired furnaces, as an adsorbent. The initial pH (pH0) affects significantly the capacity of RHA for adsorbing the metallic ions in the aqueous solution. The pH0 ≈ 6.0 is found to be the optimum for the removal of Cd(II) and Zn(II) ions by RHA. The single ion equilibrium adsorption from the binary solution is better represented by the non-competitive Redlich–Peterson (R–P) and the Freundlich models than by Langmuir model in the initial metal concentration range of 10–100 mg/l. The adsorption of Zn(II) ion is more than that of Cd(II) ion, and this trend is in agreement with the single-component adsorption data. The equilibrium metal removal decreases with increasing concentrations of the other metal ion and the combined effect of Cd(II) and Zn(II) ions on RHA is generally found to be antagonistic. Non-modified Langmuir, modified Langmuir, extended-Langmuir, extended-Freundlich, Sheindorf–Rebuhn–Sheintuch (SRS), non-modified R–P and modified R–P adsorption models were tested to find the most appropriate competitive adsorption isotherm for the binary adsorption of Cd(II) and Zn(II) ions onto RHA by minimizing the Marquardt's percent standard deviation (MPSD) error function. The extended-Freundlich model satisfactorily represents the adsorption equilibrium data of Cd(II) and Zn(II) ions onto RHA. 相似文献
77.
Veda Ramaswamy Vimal Kothiyal Indra D. Singh Rajamani Krishna 《Fresenius' Journal of Analytical Chemistry》1988,332(4):358-361
Summary A simple and fast column chromatographic procedure for the separation of vacuum residues into saturates, mono-, di-, polyaromatics and polars has been standardized using silica-alumina-bauxite adsorbents and gradient elution with n-pentane, benzene, and methanol. The cut points have been monitored employing ultraviolet and infrared spectroscopy. The method is applicable for preparative separation of short residues from processed products.
Rasche Trennung der Kohlenwasserstofftypen von Vakuum-RückstÄnden相似文献
78.
The preparation, electrical conductivity, magnetic moments, infrared, reflectance, and 57Fe Mössbauer spectra of tris(2,2,2-trichloroethoxy) iron(III) and its adducts with some oxygen and nitrogen donor ligands are reported. Cryoscopic data of the parent compound and its complex with ethylacetate suggest these compounds to be dimeric in nitrobenzene and benzene respectively. All the compounds are covalent with FeIII having distorted octahedral arrangement which is achieved through alkoxy bridging. The magnetic moments are lesser than those required for the spin only value indicating antiferromagnetic interactions in FeIII atoms. The Mössbauer spectra are explained in terms of two FeIII high spin sites corresponding to trans- and cis-positions in the structure. 相似文献
79.
80.