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51.
Murugesan S Park TJ Yang H Mousa S Linhardt RJ 《Langmuir : the ACS journal of surfaces and colloids》2006,22(8):3461-3463
Although nanotechnology has provided a rich variety of nanomaterials (1-100 nm) for in vivo medical applications, the blood compatibility of all these nanobiomaterials is still largely unexamined. Here, we report the preparation of blood-compatible carbon nanotubes (CNTs) that potentially represent the building blocks for nanodevices having in vivo applications. Activated partial thromboplastin time (APTT) and thromboelastography (TEG) studies prove that heparinization can significantly enhance the blood compatibility of nanomaterials. 相似文献
52.
Gounder MK Lin H Stein M Goodin S Bertino JR Kong AN DiPaola RS 《Biomedical chromatography : BMC》2012,26(5):650-654
2‐Deoxyglucose (2‐DG), an analog of glucose, is widely used to interfere with glycolysis in tumor cells and studied as a therapeutic approach in clinical trials. To evaluate the pharmacokinetics of 2‐DG, we describe the development and validation of a sensitive HPLC fluorescent method for the quantitation of 2‐DG in plasma. Plasma samples were deproteinized with methanol and the supernatant was dried at 45°C. The residues were dissolved in methanolic sodium acetate–boric acid solution. 2‐DG and other monosaccharides were derivatized to 2‐aminobenzoic acid derivatives in a single step in the presence of sodium cyanoborohydride at 80°C for 45 min. The analytes were separated on a YMC ODS C18 reversed‐phase column using gradient elution. The excitation and emission wavelengths were set at 360 and 425 nm. The 2‐DG calibration curves were linear over the range of 0.63–300 µg/mL with a limit of detection of 0.5 µg/mL. The assay provided satisfactory intra‐day and inter‐day precision with RSD less than 9.8%, and the accuracy ranged from 86.8 to 110.0%. The HPLC method is reproducible and suitable for the quantitation of 2‐DG in plasma. The method was successfully applied to characterize the pharmacokinetics profile of 2‐DG in patients with advanced solid tumors. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
53.
T. V. Beatriceveena Dr. A. Sree Rama Murthy Dr. S. Murugesan Dr. E. Prabhu Prof. K. I. Gnanasekar 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(6):2261-2265
Owing to a wide range of industrial applications and fundamental importance, delafossite compounds have gathered tremendous interest in research community. In this study, the formation of hexagonal nanoplates of AgInO2 mainly dominated by (00l) facets with no metallic Ag impurity, reported using a facile hydrothermal route at 180 °C using KOH as mineralizer by adopting a factorial design approach. Rietveld analysis of the powder XRD pattern and SAED confirms the rhombohedral system of AgInO2. FE-SEM image shows a uniform hexagonal plate-like morphology with an average width of about 300 nm and thickness of 70 nm. XPS and EDX analysis confirm potassium ion free AgInO2. A specific surface area of about 48.5 m2 g−1 is arrived from N2 adsorption studies. Temperature-dependent AC impedance measurements revealed an activation energy of 0.24 eV/f.u. Further, TG-DTA studies found that the compound is stable in air up to 595 °C. 相似文献
54.
Benial AM Ichikawa K Murugesan R Yamada K Utsumi H 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2006,182(2):273-282
DNP parameters relevant to Overhauser-enhanced magnetic resonance imaging (OMRI) are reported for a few nitroxyl radicals and their corresponding (15)N and (2)H enriched analogues, used in simultaneous imaging by OMRI. DNP enhancement was measured at 14.529 mT, using a custom-built scanner operating in a field-cycled mode, for different concentrations, ESR irradiation times and RF power levels. DNP enhancements increased with agent concentration up to 2.5 mM and decreased above 3 mM, in tune with ESR line broadening measured at X-band as a function of the agent concentration. The proton spin-lattice relaxation times (T(1)) measured at very low Zeeman field (14.529 mT) and the longitudinal relaxivity parameters were estimated. The relaxivity parameters were in good agreement with those independently computed from the linear region of the concentration dependent enhancement. The leakage factor showed an asymptotic increase with increasing agent concentration. The coupling parameters of (14)N- and (15)N-labeled carbamoyl-PROXYL showed the interaction between the electron and nuclear spins to be mainly dipolar in origin. Upon (2)H labeling, about 70% and 40% increases in enhancement for (15)N- and (14)N-labeled nitroxyl agents were observed, respectively. It is envisaged that the results reported here may enable better understanding of the factors determining DNP enhancement to design suitable 'beacons' for simultaneous molecular imaging by OMRI. 相似文献
55.
C. Ramesh G. Velayutham N. Murugesan V. Ganesan V. Manivannan G. Periaswami 《Ionics》2004,10(1-2):50-55
An improved polymer electrolyte membrane (PEM) fuel cell based amperometric hydrogen sensor that operates at room temperature
has been developed. The electrolyte used in the sensor is PVA/H3PO4 blend, which is a proton conducting solid polymer electrolyte. A blend of palladium and platinum coated on the membrane is
used as anode and platinum as cathode. The sensor functions as a fuel cell, H2/Pd-Pt//PVA-H3PO4//Pt/O2, and the short circuit current is found to be linearly related to the hydrogen concentration. The present study aims at investigating
the dependence of sensor behaviour on the anode composition.
Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, India, Nov. 28–30, 2003. 相似文献
56.
Ajayan Vinu Mani Karthik Masahiko Miyahara Velayudam Murugesan Katsuhiko Ariga 《Journal of molecular catalysis. A, Chemical》2005,230(1-2):151-157
CoAl-MCM-41 (X) catalysts with X = nSi/(nCo + nAl) various ratios were synthesized and ethylation of phenol with ethanol was studied in vapor-phase at temperatures between 250 and 450 °C. The products obtained were O-alkylated product (ethyl phenyl ether), C-alkylated products (2-ethylphenol and 4-ethylphenol), and C-/O-alkylated products (ethyl ethylphenyl ether). The phenol conversion increased significantly with reaction temperature over all the catalysts. The activity of the catalysts followed the order CoAl-MCM-41 (20) > CoAl-MCM-41 (50) > CoAl-MCM-41 (80). Selectivity between the C-alkylation and the O-alkylation depended on the factors such as acidity of the catalyst and the reaction temperature. CoAl-MCM-41 (20) catalyst displayed a phenol conversion of 40% and a selectivity of more than 80% for 2-ethylphenol under the optimized reaction condition. The ethanol to phenol ratios and the reactant flow rate are also influential for both activity and selectivity of CoAl-MCM-41 catalysts. 相似文献
57.
Gábor Blaskó Natesan Murugesan S.Fazal Hussain Robert D. Minard Maurice Shamma Bilge Şener Mekin Tanker 《Tetrahedron letters》1981,22(33):3135-3138
Fumarofine is not a spirobenzylisoquinoline. Rather, it is the first know reduced indenobensazepine alkaloid, and possesses the cis B/C fused structure . Rearrangement of synthetic spirobensylisoquinoline using methanesulfonyl chloride furnished indenobensazepine . Osmium tetroxide oxidation of gave cis-glysol . O-Methylfumarofine () was then obtained through pyridinium chlorochromate oxidation of . 相似文献
58.
Devasahayam N Murugesan R Matsumoto K Mitchell JB Cook JA Subramanian S Krishna MC 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2004,168(1):110-117
A method to generate shaped radiofrequency pulses for uniform excitation of electron spins in time-domain radio frequency (RF) electron paramagnetic resonance (EPR) imaging is presented. A commercial waveform generator was integrated with the transmit arm of the existing time-domain RF-EPR spectrometer to generate tailored excitation pulses with sub-nano second resolution for excitation with a 90 degrees flip-angle. A truncated sinc [sin(x)/x] pulse, tailored to compensate for the Q-profile (RF frequency response) of the resonator, was shown to yield images from phantom objects as well as in vivo images, with minimal distortion. These studies point to the advantages in using shaped sinc pulses to achieve improved uniform excitation over a relatively wide bandwidth region in time-domain RF-EPR imaging (RF-FT-EPRI). 相似文献
59.
Yamada K Murugesan R Devasahayam N Cook JA Mitchell JB Subramanian S Krishna MC 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2002,154(2):287-297
The performance of two electron paramagnetic resonance (EPR) spectrometers/imagers, one configured in pulsed mode and the other in continuous wave (CW) mode, at an operating frequency of 300 MHz is compared. Using the same resonator (except for altered Q-factors), identical samples and filling factors in the two techniques have been evaluated for their potentials and limitations for in vivo spectroscopic and imaging applications. The assessment is based on metrics such as sensitivity, spatial and temporal resolution, field of view, image artifacts, viable spin probes, and subjects of study. The spectrometer dead time limits the pulsed technique to samples with long phase memories (>275 ns). Nevertheless, for viable narrow-line spin probes, the pulsed technique offers better sensitivity and temporal resolution. The CW technique, on the other hand, does not restrict the choice at spin probes. In addition, the phase-sensitive narrow-band detection of the CW technique gives artifact-free images even for large objects. Selected examples illustrating the performance of the CW and pulsed techniques are presented to put the capabilities of the two techniques in perspective. 相似文献
60.
Hartmann M Vinu A Elangovan SP Murugesan V Böhlmann W 《Chemical communications (Cambridge, England)》2002,(11):1238-1239
The direct synthesis of the new mesoporous molecular sieve AlSBA-1 containing exclusively tetrahedrally coordinated aluminium and the catalytic activity of the novel material in the isomerization of n-decane are reported. 相似文献