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1.
Morey Timothy E. Varshney Manoj Flint Jason A. Seubert Christoph N. Smith W. Brit Bjoraker David G. Shah Dinesh O. Dennis Donn M. 《Journal of nanoparticle research》2004,6(2):159-170
Background: Although microemulsion-based nanoparticles (MEs) may be useful for drug delivery or scavenging, these benefits must be balanced against potential nanotoxicological effects in biological tissue (bio-nano interface). We investigated the actions of assembled MEs and their individual components at the bio-nano interface of thrombosis and hemolysis in human blood.
Methods: Oil-in-water MEs were synthesized using ethylbutyrate, sodium caprylate, and pluronic F-68 (ME4) or F-127 (ME6) in 0.9% NaClw/v. The effects of MEs or components on thrombosis were determined using thrombo-elastography, platelet contractile force, clot elastic modulus, and platelet counting. For hemolysis, ME or components were incubated with erythrocytes, centrifuged, and washed for measurement of free hemoglobin by spectroscopy.
Results and conclusions: The mean particle diameters (polydispersity index) for ME6 and ME4 were 23.6 ± 2.5 nm (0.362) and 14.0 ± 1.0 nm (0.008), respectively. MEs (0, 0.03, 0.3, 3 mM) markedly reduced the thromboelastograph maximal amplitude in a concentration-dependent manner (49.0 ± 4.2, 39.0 ± 5.6, 15.0 ± 8.7, 3.8 ± 1.3 mm, respectively), an effect highly correlated (r2 = 0.94) with similar changes caused by pluronic surfactants (48.7 ± 10.9, 30.7 ± 15.8, 20.0 ± 11.3, 2.0 ± 0.5) alone. Neither oil nor sodium caprylate alone affected the thromboelastograph. The clot contractile force was reduced by ME (27.3 ± 11.1–6.7 ± 3.4 kdynes/cm2, P = 0.02, n = 5) whereas the platelet population not affected (175 ± 28–182 ± 23 106/ml, P = 0.12, n = 6). This data suggests that MEs reduced platelet activity due to associated pluronic surfactants, but caused minimal changes in protein function necessary for coagulation. Although pharmacological concentrations of sodium caprylate caused hemolysis (EC50 = 213 mM), MEs and pluronic surfactants did not disrupt erythrocytes. Knowledge of nanoparticle activity and potential associated nanotoxicity at this bio-nano interface enables rational ME design for in vivo applications. 相似文献
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The concept of strong interactions need not be limited to the sector of physics taken by QCD. While this domain is investigated by RHIC, LHC will be able to probe potential new strong interactions simultaneously: Finding the precise mechanism for electroweak symmetry breaking is one of the prime problems of physics. Intricately linked to this point is the question after the true nature or even the existence of the Higgs boson. Here, we present stronly interacting theories providing an explanation for the hierarchy problem and leading to a light composite Higgs boson, favoured by experimental data. Our variation of the standard model is consistent with precision data. We achieve this accordance by using technifermions in a higher representation of their gauge group. Anomaly conditions require at least one extra lepton family for some of the theories whereby they contain a natural dark matter candidate. We can accurately determine the masses of said leptons from experimental data. 相似文献
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Ashwani K. Padthe Nalin A. Chaturvedi Dennis S. Bernstein Sanjay P. Bhat Anthony M. Waas 《International Journal of Non》2008,43(4):277-291
We study a linearly damped preloaded two-bar linkage that exhibits hysteresis due to the presence of multiple attracting equilibria. The dynamics at the unstable equilibrium, through which a snap-through buckle occurs, are not linearizable due to a solution-dependent singularity. We stabilize the unstable equilibrium using two distinct non-linear controllers. The feedback-linearization controller requires knowledge of the linkage parameters, whereas the robust version of the intrinsic non-linear proportional-derivative controller requires only an upper bound on the stiffness. 相似文献
9.
Roberto Ballini Dennis Fiorini Maria Victoria Gil Alessandro Palmieri 《Tetrahedron》2004,60(12):2799-2804
Nitroalkanes have been found to give good yields in Michael and nitroaldol (Henry) reactions by the use of a catalytic amount (10 mol%) of CTAOH, at room temperature and under solvent free conditions and in very short reaction times. The methods do not need a large excess of the nitroalkanes and show good chemoselectivity toward further functionalities. 相似文献
10.
Isosteric derivatives and analogues of the 7-keto-8-aminopelargonic acid (KAPA), 7,8-diaminopelargonic acid (DAPA) and desthiobiotin (DTB) vitamer intermediates involved in the biosynthetic pathway of biotin were prepared and evaluated as potential herbicides. The most active compound was desmethyl-KAPA which displayed a GR50 (concentration of the active compound that causes a 50% growth inhibition) value of 8 ppm, where values <50 ppm are considered herbicidal. Other KAPA analogs where the terminal Me group was replaced by bulkier substituents such as Et, i-Pr and HOCH2 showed moderate activity. 相似文献