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991.
An instance of the quadratic assignment problem (QAP) with cost matrix is said to be linearizable if there exists an instance of the linear assignment problem (LAP) with cost matrix such that for each assignment, the QAP and LAP objective function values are identical. The QAP linearization problem can be solved in time. However, for the special cases of Koopmans–Beckmann QAP and the multiplicative assignment problem the input size is of . We show that the QAP linearization problem for these special cases can be solved in time. For symmetric Koopmans–Beckmann QAP, Bookhold [I. Bookhold, A contribution to quadratic assignment problems, Optimization 21 (1990) 933–943.] gave a sufficient condition for linearizability and raised the question if the condition is necessary. We show that Bookhold’s condition is also necessary for linearizability of symmetric Koopmans–Beckmann QAP. 相似文献
992.
993.
Pemberton C Hoffman R Aserin A Garti N 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2011,208(2):262-269
Silica is used as an important component for NMR “chromatography”. In this study the effect of the binding strength to silica of a variety of compounds on their diffusion rate is measured for the first time. Over two orders of magnitude of diffusion difference enhancement was obtained in the presence of silica for some compounds. An explanation of the enhancement is given that also allows one to predict the “chromatographic” behavior of new compounds or mixtures. The binding strength is divided into categories of weakly bound, singly bound and multiply bound. Carboxylates, sulfonates, and diols are found to be particularly strongly bound and to diffuse up to 2½ orders of magnitude more slowly in the presence of silica. 相似文献
994.
Cytotoxicity and fluorescence studies of silica-coated CdSe quantum dots for bioimaging applications
Muthunayagam Vibin Ramachandran Vinayakan Annie John Vijayamma Raji Chellappan S. Rejiya Naresh S. Vinesh Annie Abraham 《Journal of nanoparticle research》2011,13(6):2587-2596
The toxicological effects of silica-coated CdSe quantum dots (QDs) were investigated systematically on human cervical cancer
cell line. Trioctylphosphine oxide capped CdSe QDs were synthesized and rendered water soluble by overcoating with silica,
using aminopropyl silane as silica precursor. The cytotoxicity studies were conducted by exposing cells to freshly synthesized
QDs as a function of time (0–72 h) and concentration up to micromolar level by Lactate dehydrogenase assay, MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium
Bromide] assay, Neutral red cell viability assay, Trypan blue dye exclusion method and morphological examination of cells
using phase contrast microscope. The in vitro analysis results showed that the silica-coated CdSe QDs were nontoxic even at
higher loadings. Subsequently the in vivo fluorescence was also demonstrated by intravenous administration of the QDs in Swiss
albino mice. The fluorescence images in the cryosections of tissues depicted strong luminescence property of silica-coated
QDs under biological conditions. These results confirmed the role of these luminescent materials in biological labeling and
imaging applications. 相似文献
995.
Let ?? be a bounded symmetric domain of type IV and dimension bigger than four. We show that a Stein manifold of the same dimension as ?? and with the same automorphism group is biholomorphic to ??. 相似文献
996.
Abraham Colin-Molina Marcus J. Jellen Dr. Joelis Rodríguez-Hernández Dr. Miguel Eduardo Cifuentes-Quintal Jorge Barroso Dr. Rubén A. Toscano Prof. Gabriel Merino Prof. Braulio Rodríguez-Molina 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(51):11727-11733
Two new crystalline rotors 1 and 2 assembled through N−H⋅⋅⋅N hydrogen bonds by using halogenated carbazole as stators and 1,4-diaza[2.2.2]bicyclooctane (DABCO) as the rotator, are described. The dynamic characterization through 1H T1 relaxometry experiments indicate very low rotational activation barriers (Ea) of 0.67 kcal mol−1 for 1 and 0.26 kcal mol−1 for 2 , indicating that DABCO can reach a THz frequency at room temperature in the latter. These Ea values are supported by solid-state density functional theory computations. Interestingly, both supramolecular rotors show a phase transition between 298 and 250 K, revealed by differential scanning calorimetry and single-crystal X-ray diffraction. The subtle changes in the crystalline environment of these rotors that can alter the motion of an almost barrierless DABCO are discussed here. 相似文献
997.
Anuji Abraham Omar Elkassabany Mary E. Krause Andrew Ott 《Magnetic resonance in chemistry : MRC》2019,57(10):873-877
Determining the moisture content in lyophilized solids is a fundamental step towards predicting the quality and stability of lyophilized products, but conventional methods are time-consuming, invasive, and destructive. High levels of residual moisture in a lyophilized product can lead to cake collapse, product degradation, and reduced shelf life. The aim of this study was to develop a fast, noninvasive, nondestructive, and inexpensive method for determining the moisture content in a lyophilized monoclonal antibody (mAb) formulation using benchtop low-field time-domain nuclear magnetic resonance spectroscopy. 相似文献
998.
T.G. Akin Sharon Kennedy Ben Dribus Jeremy L. Marzuola Lise Johnson Jason Alexander E.R.I. Abraham 《Optics Communications》2012,285(1):84-89
Multiply-connected traps for cold, neutral atoms fix vortex cores of quantum gases. Laguerre–Gaussian laser modes are ideal for such traps due to their phase stability. We report theoretical calculations of the Bose–Einstein condensation transition properties and thermal characteristics of neutral atoms trapped in multiply connected geometries formed by Laguerre–Gaussian (LGpl) beams. Specifically, we consider atoms confined to the anti-node of a LG01 laser mode detuned to the red of an atomic resonance frequency, and those confined in the node of a blue-detuned LG11 beam. We compare the results of using the full potential to those approximating the potential minimum with a simple harmonic oscillator potential. We find that deviations between calculations of the full potential and the simple harmonic oscillator can be up to 3%–8% for trap parameters consistent with typical experiments. 相似文献
999.
In this article, we use a unified approach to prove several classes of planar graphs are DP-3-colorable, which extend the corresponding results on 3-choosability. 相似文献
1000.
Nagaraja SreeHarsha Jagadeesh G. Hiremath Rajesh Kumar Aitha Abraham J. Domb Bandar E. Al‐Dhubiab Chandramouli Ramnarayanan Abdullah Mossa Alzahrani Katharigatta N. Venugopala Sabah H. Akrawi Mahesh Attimarad Anroop B. Nair 《先进技术聚合物》2019,30(10):2613-2622
This research presents a thin‐film hydration‐solvent evaporation method to formulate the paclitaxel loaded poly (DL lactic acid co castor oil) 4:6 with poloxamer‐F68 cylindrical shape nanoparticles. The particles were less than 250 nanometers (nm) in size, with an average width of 60 nm and an average length of 100 nm. The percent yield, encapsulation efficiency (EE), and percent drug loading (DL) were detected. This approach produces drug loading values between 5% and 20% w/w. X‐ray powder diffraction (XRD) identified the physicochemical properties of nanoparticles differential scanning calorimetry (DSC) and Fourier‐transform infrared spectroscopy (FTIR). The investigation shows that the drug is molecularly dispersed in polymers or given in an amorphous or semicrystalline state. Horizontal water bath shaker technology considered the in vitro release of PTX loaded nanoparticles under sink conditions. Poly (DL lactic acid co castor oil) 4:6 nanoparticles exhibited a sustained release analysis. At the end of 30 hours, the percent cumulative drug release from the formulations was between 74.52% and 92.87% for F1 and F4. In vitro cytotoxicity assays indicate that PTX having p (DLLA:CO60:40) nanoparticles have a higher cytotoxic effect on MCF‐7/ADR. 相似文献