1,145 research outputs found
Synthesis, structures and antitumor activity of the first crown ester-linked bipyridyl platinum complexes
No full textThree new crown ester-linked bipyridine homologs with three, four or five ethylene glycol units, which are bulky and soluble in both hydrophilic and lipophilic;media, were synthesized. The reaction of the appropriate macrocycles with K2PtCl4 in water gave yellow cisplatin analogs in good yield. These complexes were converted to carboplatin analogs by exchange of the leaving group. All the compounds were characterized by elemental analysis and various spectroscopic methods. Carboplatin analogs showed good solubility in both hydrophilic and lipophilic media. The crystal structure of 2c, the carboplatin analog with macrocycles containing five ethylene glycol units, was determined by X-ray diffraction: space group P (1) over bar, a = 9.798(1), b = 12.580(3), c = 13.945(2) Angstrom, alpha =108.61(2), beta = 94.59(1), gamma = 97.42(2)degrees, Z = 2, R = 0.0618. Some of platinum complexes Showed a moderate cytotoxic effect on both murine leukemia L1210 and P388 even though they do not have any NH proton. (C) 1999 Elsevier Science Inc. All rights reserved.Korea Research Foundation and the Korea Science and Engineering Foundatio
Updates on Paget’s Disease of Bone
No full textPaget's disease of the bone is a prevalent bone disease characterized by disorganized bone remodeling; however, it is comparatively uncommon in East Asian countries, including China, Japan, and Korea. The exact cause still remains unknown. In genetically susceptible individuals, environmental triggers such as paramyxoviral infections are likely to cause the disease. Increased osteoclast activity results in increased bone resorption, which attracts osteoblasts and generates new bone matrix. Fast bone resorption and formation lead to the development of disorganized bone tissue. Increasing serum alkaline phosphatase or unique radiographic lesions may serve as the diagnostic indicators. Common symptoms include bone pain, bowing of the long bones, an enlarged skull, and hearing loss. The diagnosis is frequently confirmed by radiographic and nuclear scintigraphy of the bone. Further, bisphosphonates such as zoledronic acid and pamidronate are effective for its treatment. Moreover, biochemical monitoring is superior to the symptoms as a recurrence indicator. This article discusses the updates of Paget's disease of bone with a clinical case
HETEROLEPTIC CROWN THIOETHER COMPLEXES - SYNTHESIS AND CHARACTERIZATION OF [M(CO)3(9S3)] (M = CR, MO, W) - CRYSTAL-STRUCTURE OF [W(CO)3 (9S3)](9S3 = 1,4,7-TRITHIACYCLONONANE)
No full textThis work was in part supported by the Korea Science and Engineering Foundation. YD thanks Yun Am Cultural Foundation
HETERODINUCLEAR GROUP-6 METALLACARBORANES - SYNTHESIS AND CHARACTERIZATION OF [CLOSO-3,3,3-(CO)3-3-SNPH3-3,1,2-MC2B9H11]-(M = CR, MO, W)
No full textHeterodinuclear group 6 metallacarborane anions [closo-3,3,3-(CO)3-3-SnPh3-3,1,2-MC2B9H11]-(M = Cr, 2; Mo, 3; W, 4) were prepared from the equimolar reaction systems of Tl2C2B9H11/M(CO)3(MeCN)3/SnPh3Cl/(PPN)Cl in MeCN as the [PPN]+ (PPN+ = bis(triphenylphophoranylidene ammonium cation) salts and were characterized by various means including multinuclear NMR and single-crystal X-ray diffraction. Crystals of [PPN].4 are monoclinic, C2/c, with a = 45.777(4), b = 11.669(1), c = 26.826(3) angstrom, beta = 125.134(2)degrees, V = 11718 angstrom 3 and Z = 8. Convergence was achieved with R (R(w)) = 6.7 (8.0)% for 5487 (I > 3-sigma(I)) observed reflections. The nido anion C2B9H11(2-) interacts with W via the C2B3 pentagonal] plane and forms the closo WC2B9 geometry. The W-Sn distance of 2.825(1) angstrom and the observation of 1J(Sn-119-W-183) = 262 Hz in Sn-119 NMR spectrum of 4 establish the presence of a W-Sn bonding interaction. The structural integrities of 2, 3 and 4 are similar and each compound remains intact in solution.Korea Science and Engineering
Foundation and in part by the Office of Naval Researc
Sensitivity Enhancement of a Miniaturized Surface Plasmon Resonance Sensor Using Combination of Self-Assembled Mono layer and Protein G
No full textThe detection capabilities of surface plasmon resonance (SPR) sensor chips modified with protein G, a self-assembled monolayer (SAM), and a combination of protein G and a SAM were investigated and compared using a miniaturized SPR sensor system. The miniaturized SPR system had two flow channels, with one used as a reference. To immobilize the antibodies on the SPR sensor chip for the detection of C-reactive protein (CRP), different linker molecules were formed on the gold SPR sensor chip at the beginning of the experiment. The CRP has been reported as a biomarker of future cardiovascular events. The antibody of CRP and bovine serum albumin (BSA) were then sequentially injected. The responses to CRP at concentrations of 0.5, 1, 3, and 5 μg/ml were observed and the sensitivities of each system compared. The SPR sensor chips modified with the protein G on the SAM layer exhibited the highest sensitivity and a stable linearity. The results demonstrated the feasibility of using the proposed SPR immunosensors for detecting CRP for early diagnosis without any additional chemical treatments. Copyright © 2012 American Scientific Publishers.
Exposure of Iron Nanoparticles to Arabidopsis thaliana Enhances Root Elongation by Triggering Cell Wall Loosening
No full textIn this study, we investigated the effect of nZVI on plant root elongation in Arabidopsis thaliana and showed, for the first time, that nZVI enhanced root elongation by inducing OH radical-induced cell wall loosening.. Exposure of plants to 0.5 g/L nZVI enhanced root elongation by 150-200% over that in the control, and further mechanistic studies showed that this occurred via nZVI-mediated OH radical-induced cell wall loosening. The oxidation capacity of nZVI, leading to release of H2O2, allowed it to cause OH radical-induced cell wall loosening in roots. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometers (MALDI-TOFMS)-based analysis clearly revealed that pectin-polysaccharides in roots were degraded; they are one of the main matrix-polysaccharide-connecting and load-bearing polymers in cell walls. Rapid elongation led to structural changes in root cell walls: reduction of cell wall thickness and a bias on the orientation of cellulose microfibrils. Additionally, the asymmetrical distribution of tensional strength resulted from the OH radical-induced cell wall loosening enhanced endocytosis. These findings emphasize that OH radical-induced cell wall loosening is important for mechanical regulation of the cell wall and provide new insights into the cellular responses of plants exposed to reactive metal nanoparticles.X114944sciescopu
Author's reply to comment on ""Biological removal of polychlorinated dibenzo-p-dioxins from incinerator fly ash by sphingomonas wittichii RW1"" by Rolf U. Halden
No full textX111sciescopu
FOURIER TRANSFORM MICROWAVE SPECTROSCOPY OF SCS (X), YS (X) AND VS (X)
No full textAuthor Institution: Department of Chemistry and Steward Observatory, University of Arizona, Tucson, AZ 85721Pure rotational spectra of three transition-metal monosulfides, ScS, YS, and VS, have been recorded using Fourier transform microwave spectroscopy (FTWM) in the range 10-40 GHz. These molecules are all free radicals and have been synthesized in a mixture of HS gas with metal vapor, obtained by laser ablation of a metal rod. In the case of ScS and VS, a discharge was necessary to successfully produce the molecules. For YS, the N=10, 21, 32 and 43 rotational transitions have been recorded. For ScS and VS, the N=10, N=21 and N=32 have been obtained. Vanadium, scandium and yttrium hyperfine structures were resolved for these species. Rotational, fine structure and hyperfine coupling constants have been determined for all three radicals. This works completes the high-resolution pure rotational measurements of 3d transition-metal monosulfides, and provides the most accurate values of the hyperfine parameters for these molecules to date. Bond lengths and spectroscopic parameters will be presented
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