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排序方式: 共有689条查询结果,搜索用时 36 毫秒
661.
Dr. Vít Herynek Dr. Karolína Turnovcová Dr. Andrea Gálisová Dr. Ondřej Kaman Dr. Dana Mareková Dr. Jakub Koktan Dr. Magda Vosmanská Lucie Kosinová Dr. Pavla Jendelová 《ChemistryOpen》2019,8(2):155-165
Manganese-zinc ferrite nanoparticles were synthesized by using a hydrothermal treatment, coated with silica, and then tested as efficient cellular labels for cell tracking, using magnetic resonance imaging (MRI) in vivo. A toxicity study was performed on rat mesenchymal stem cells and C6 glioblastoma cells. Adverse effects on viability and cell proliferation were observed at the highest concentration (0.55 mM) only; cell viability was not compromised at lower concentrations. Nanoparticle internalization was confirmed by transmission electron microscopy. The particles were found in membranous vesicles inside the cytoplasm. Although the metal content (0.42 pg Fe/cell) was lower compared to commercially available iron oxide nanoparticles, labeled cells reached a comparable relaxation rate R2, owing to higher nanoparticle relaxivity. Cells from transgenic luciferase-positive rats were used for in vivo experiments. Labeled cells were transplanted into the muscles of non-bioluminescent rats and visualized by MRI. The cells produced a distinct hypointense signal in T2- or T2*-weighted MR images in vivo. Cell viability in vivo was verified by bioluminescence. 相似文献
662.
Convergence of Monotone Iterations for Differential Problem 总被引:4,自引:0,他引:4
Tadeusz Jankowski 《数学学报(英文版)》2000,16(4):711-720
We use the method of lower and upper solutions combined with monotone iterations to differential problems with a parameter.
Existence of extremal solutions to such problems is proved.
Received April 15, 1999, Revised December 6, 1999, Accepted July 18, 2000 相似文献
663.
Roman Shayduk David Pennicard Konstantin Krausert Peter Gaal Sergey Volkov Vedran Vonk Uta Hejral Maciej Jankowski Matthias Reinhardt Wolfram Leitenberger Andreas Stierle 《Journal of synchrotron radiation》2017,24(5):1082-1085
A simple experiment to characterize the gating properties of X‐ray area detectors using pulsed X‐ray sources is presented. For a number of time‐resolved experiments the gating uniformity of area detectors is important. Relative gating delays between individual modules and readout chips of PILATUS2 series area X‐ray detectors have been observed. For three modules of a PILATUS 300K‐W unit the maximum gating offset between the modules is found to be as large as 30 ns. On average, the first photosensor module is found to be triggered 15 ns and 30 ns later than the second and the third modules, respectively. 相似文献
664.
Robert Pluskota Karol Jaroch Piotr Koliski Blanka Ziomkowska Agnieszka Lewiska Stefan Kruszewski Barbara Bojko Marcin Koba 《Molecules (Basel, Switzerland)》2021,26(17)
2-Arylidene-indan-1,3-done derivatives have very different properties, thanks to which they find various applications in science, medicine, and industry. Selected derivatives show antiviral, antibacterial, and anti-inflammatory activity. This paper presents a procedure for the synthesis of a series of indan-1,3-dione derivatives that present antiproliferative activity. The aim of the work was to develop a method of simple synthesis and purification, evaluate the fulfillment of the Lipiński’s and Veber’s rule, and determine the potential scope of application of the obtained series of compounds. The structure of the synthesized compounds was confirmed, and their lipophilicity was determined using experimental and computational methods. Their antiproliferative activity against selected cell lines was tested in accordance with the MTT protocol; the ability to bind to albumin was tested, and the parameters related to the toxicity of substances in silico were determined. The selected compounds which showed antiproliferative activity were strongly bound to albumin and, in most cases, met the Lipiński’s and Veber’s rule. Thus, the obtained results suggest that 2-arylidene-indan-1,3-done derivatives appear to be good candidates for drugs with a potential leading structure for further development. 相似文献
665.
An efficient synthesis of 17-epi-calcitriol 2, an epimer of natural hormone, via 17-epi-cholesterol 5a is described. Synthesis of 5a includes palladium-catalyzed cyclopropanation of the common androstane derivative 7 with an alkyl diazoacetate, reductive fission of the less shielded side of cyclopropane carboxylic acid esters 6, oxidation of the products into acid 11a, and alkylation of ester 11b. Photolysis of 7,8-dedydro-17-epi-25-hydroxycholesterol 19b and consecutive thermal rearrangement gave a mixture of several products that was subjected to ozonolysis to provide, after chromatography, hydroxy ketone 3a. The silyl derivative 3b was coupled with the respective ring A building block. 相似文献
666.
Rama Subba Reddy Gorla Frank Jankowski David Textor 《International Journal of Heat and Fluid Flow》1988,9(4):421-426
An analysis is presented to investigate the time-mean characteristics of the laminar boundary layer near an axisymmetric stagnation point when the velocity of the oncoming flow relative to the body oscillates. Different solutions are obtained for the small and high values of the reduced frequency parameter. The range of Reynolds number considered was from 0.01 to 100. Numerical solutions for the velocity functions are presented, and the wall values of the velocity gradients are tabulated. 相似文献
667.
668.
669.
[reaction: see text] Substituted vinylphosphine oxides have been prepared in good yield and exclusive (E)-olefin selectivity via olefin cross-metathesis using Grubbs and Hoveyda-type ruthenium catalysts. In addition, metathesis of chiral vinylphosphine oxides proceeds without racemization of the phosphorus chirality center, providing easy access to functionalized chiral nonracemic (E)-alkenylphosphine oxides. 相似文献
670.
The Horn-Weinstein formula and the variational principle, combined with numerical results for a few many-electron systems, are used to provide support for a conjecture that the exact ground-state wave function for a Hamiltonian system containing up to two-body terms may be represented by an exponential cluster expansion employing a finite two-body operator. 相似文献