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21.
Saqib Ali Syed Usman Ahmad Saira Shahzadi Sadiq‐ur‐Rehman Masood Parvez Muhammad Mazhar 《应用有机金属化学》2005,19(1):201-201
Me2Sn(S2CN(CH2)5)Cl contains five‐coordinated tin with a bidentate dithiocarbamate ligand spanning equatorial and axial positions in a distorted trigonal bipyramidal geometry. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
22.
Nathan Hollingsworth Graeme A. Horley Muhammed Mazhar Mary F. Mahon Kieran C. Molloy Peter W. Haycock Christopher P. Myers Gary W. Critchlow 《应用有机金属化学》2006,20(10):687-695
Tin(II) methoxide reacts with N,N′‐dimethylaminoethanol (dmaeH) to yield Sn(dmae)2 ( 1 ) along with small amounts of the hydrolysis product Sn6(O)4(dmae)4 ( 2 ). The geometrically more regular iso‐structural cage Sn6(O)4(OEt)4 ( 3 ) was obtained as the only tractable product isolated from reaction of 2 and Sb(OEt)3, while 1 reacted with CdX2 (X = acac, I) to afford Sn(dmae)2Cd(acac)2 ( 4 ) and Sn(dmae)2CdI2 ( 5 ). The X‐ray structures of 2, 3 and 4 are reported. Decomposition of 4 under aerosol‐assisted chemical vapour deposition conditions leads to amorphous tin oxide films with no detectable cadmium (i.e. ca < 2% cadmium), rather than a stoichiometric Sn:Cd oxide. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
23.
A.A. Dosiyev Z. Mazhar S.C. Buranay 《Journal of Computational and Applied Mathematics》2010,235(3):805-816
An extremely accurate, exponentially convergent solution is presented for both symmetric and non-symmetric Laplacian problems on L-shaped domains by using one-block version of the block method (BM). A simple and highly accurate formula for computing the stress intensity factor is given. Comparisons with various results in the literature are included. 相似文献
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Facilitated transport of silver(I) ions in acidic medium, across a supported liquid membrane (SLM) by using triethanolamine (TEA) as carrier, dissolved in cyclohexanone, has been investigated. The parameters studied are HNO3 concentration variation in the feed, pH of the feed solution, carrier concentration in the membrane phase, silver(I) ions concentration in the feed phase and KCN concentration in the stripping phase. Increase in H+ concentration by increasing HNO3 concentration from 0.5 to 1 M results into an increase in silver ions flux but a decrease in flux has been found beyond 1 M HNO3 concentration in the feed, providing a maximum flux of 3.21 × 10−7 mol/m2 s at 1 M HNO3. Increase in TEA concentration inside the membrane enhances flux with its maximum value at 2.25 M TEA. Further increase in the concentration of TEA leads to a decreased rate of transport due to the increase in viscosity of membrane liquid. The optimum conditions for Ag(I) ions transport are 1 M HNO3 (feed), 2.25 M TEA (membrane) and 1.5 M KCN in the stripping phase. It has been observed that Ag(I) flux across the membrane tends to increase with increase in Ag(I) ions concentration in the feed phase. Applying the studied conditions to silver plating waste solutions, Ag ions have been removed up to 99% in a time interval of 5 h. 相似文献
26.
Some novel lower homologues of diorganotin derivatives of germyl substituted propanoic acids with general formula [Ar(3)GeCH(R(1))CH(R(2))COO](2)SnR(2)(3), where Ar = p-CH(3)C(6)H(4), C(6)H(5), R(1) = p-CH(3)C(6)H(4), p-CH(3)OC(6)H(4), o-CH(3)OC(6)H(4), C(6)H(5), R(2) = H, CH(3), R(3) = CH(3), C(2)H(5) have been prepared by the condensation reaction of dialkyltin oxide and triarylgermyl(substituted) propanoic acid in 1 : 2 M ratio, respectively, and were characterized by IR, multinuclear ((1)H, (13)C, (119)Sn) NMR, (119 m)Sn M?ssbauer spectroscopy. The synthesized compounds were also screened for their toxicity and possible antibacterial, antifungal activities and found some encouraging results. 相似文献
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Siddiqua A Luo Y Meyer V Swanson MA Yu X Wei G Zheng J Eaton GR Ma B Nussinov R Eaton SS Margittai M 《Journal of the American Chemical Society》2012,134(24):10271-10278
Tau pathology in Alzheimer's disease is intimately linked to the deposition of proteinacious filaments, which akin to infectious prions, have been proposed to spread via seeded conversion. Here we use double electron-electron resonance (DEER) spectroscopy in combination with extensive computational analysis to show that filaments of three- (3R) and four-repeat (4R) tau are conformationally distinct. Distance measurements between spin labels in the third repeat, reveal tau amyloid filaments as ensembles of known β-strand-turn-β-strand U-turn motifs. Whereas filaments seeded with 3R tau are structurally homogeneous, filaments seeded with 4R tau are heterogeneous, composed of at least three distinct conformers. These findings establish a molecular basis for the seeding barrier between different tau isoforms and offer a new powerful approach for investigating the composition and dynamics of amyloid fibril ensembles. 相似文献
29.
In this paper, a sensitive water-soluble fluorescent conjugated polymer biosensor for catecholamine (dopamine DA, adrenaline AD and norepinephrine NE) was developed. In the presence of horse radish peroxidase (HRP) and H(2)O(2), catecholamine could be oxidized and the oxidation product of catecholamine could quench the photoluminescence (PL) intensity of poly(2,5-bis(3-sulfonatopropoxy)-1,4-phenylethynylenealt-1,4-poly(phenylene ethynylene)) (PPESO(3)). The quenching PL intensity of PPESO(3) (I(0)/I) was proportional to the concentration of DA, AD and NE in the concentration ranges of 5.0 × 10(-7) to 1.4 × 10(-4), 5.0 × 10(-6) to 5.0 × 10(-4), and 5.0 × 10(-6) to 5.0 × 10(-4) mol L(-1), respectively. The detection limit for DA, AD and NE was 1.4 × 10(-7) mol L(-1), 1.0 × 10(-6) and 1.0 × 10(-6) mol L(-1), respectively. The PPESO(3)-enzyme hybrid system based on the fluorescence quenching method was successfully applied for the determination of catecholamine in human serum samples with good accuracy and satisfactory recovery. The results were in good agreement with those provided by the HPLC-MS method. 相似文献
30.
Antioxidant and Anti-Inflammatory Effects of Peganum harmala Extracts: An In Vitro and In Vivo Study
Malik Waseem Abbas Mazhar Hussain Muhammad Qamar Sajed Ali Zahid Shafiq Polrat Wilairatana Mohammad S. Mubarak 《Molecules (Basel, Switzerland)》2021,26(19)
Peganum harmala (P. harmala) belongs to the family Zygophyllaceae, and is utilized in the traditional medicinal systems of Pakistan, China, Morocco, Algeria, and Spain to treat several chronic health disorders. The aim of the present study was to identify the chemical constituents and to evaluate the antioxidant, anti-inflammatory, and toxicity effects of P. harmala extracts both in vitro and in vivo. Sequential crude extracts including 100% dichloromethane, 100% methanol, and 70% aqueous methanol were obtained and their antioxidant and anti-inflammatory effects evaluated both in vitro and in vivo. The anti-inflammatory effect of the extract was investigated using the carrageenan-induced paw edema method in mice, whereas the toxicity of the most active extract was evaluated using an acute and subacute toxicity rat model. In addition, we have used the bioassay-guided approach to obtain potent fractions, using solvent–solvent partitioning and reversed phase high performance liquid chromatography from active crude extracts; identification and quantification of compounds from the active fractions was achieved using electrospray ionization mass spectrometry and high performance liquid chromatography techniques. Results revealed that the 100% methanol extract of P. harmala exhibits significant in vitro antioxidant activity in DPPH assay with an IC50 of 49 µg/mL as compared to the standard quercetin with an IC50 of 25.4 µg/mL. The same extract exhibited 63.0% inhibition against serum albumin denaturation as compared to 97% inhibition by the standard diclofenac sodium in an in vitro anti-inflammatory assay, and in vivo anti-inflammatory against carrageenan-induced paw edema (75.14% inhibition) as compared to 86.1% inhibition caused by the standard indomethacin. Furthermore, this extract was not toxic during a 14 day trial of acute toxicity when given at a dose of 3 g/kg, indicating that the lethal dose (LD50) of P. harmala methanol extract was greater than 3 g/kg. P. harmala methanolic fraction 2 obtained using bioassay-guided fractionation showed the presence of quinic acid, peganine, harmol, harmaline, and harmine, confirmed by electrospray ionization mass spectrometry and quantified using external standards on high performance liquid chromatography. Taken all together, the current investigation further confirms the antioxidant, anti-inflammatory, and safety aspects of P. harmala, which justifies its use in folk medicine. 相似文献