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81.
The nominal (Hg1−x
Re
x
)Sr2CuO4+δ (x=0.10 and 0.20) samples were synthesized at ∼ 920°C in partial vacuum. The compound with x=0.10 exhibits superconductivity at ∼ 54 K while the composition x=0.20 is non-superconducting down to 5 K. On cooling below 10 K in an applied field of 4 kOe, the former causes a noticeable
upturn in the field cooled (FC) magnetization signal. Such a change in magnetic response is also reflected in the magnetic
hysteresis loop generated at 9 K. We attribute this effect to a paramagnetic contribution arising from Re in (Hg,Re)-1201
phase. 相似文献
82.
Subramanian B Kim N Lee W Spivak DA Nikitopoulos DE McCarley RL Soper SA 《Langmuir : the ACS journal of surfaces and colloids》2011,27(12):7949-7957
Droplet microfluidics performed in poly(methyl methacrylate) (PMMA) microfluidic devices resulted in significant wall wetting by water droplets formed in a liquid-liquid segmented flow when using a hydrophobic carrier fluid such as perfluorotripropylamine (FC-3283). This wall wetting led to water droplets with nonuniform sizes that were often trapped on the wall surfaces, leading to unstable and poorly controlled liquid-liquid segmented flow. To circumvent this problem, we developed a two-step procedure to hydrophobically modify the surfaces of PMMA and other thermoplastic materials commonly used to make microfluidic devices. The surface-modification route involved the introduction of hydroxyl groups by oxygen plasma treatment of the polymer surface followed by a solution-phase reaction with heptadecafluoro-1,1,2,2-tetrahydrodecyl trichlorosilane dissolved in fluorocarbon solvent FC-3283. This procedure was found to be useful for the modification of PMMA and other thermoplastic surfaces, including polycyclic olefin copolymer (COC) and polycarbonate (PC). Angle-resolved X-ray photoelectron spectroscopy indicated that the fluorination of these polymers took place with high surface selectivity. This procedure was used to modify the surface of a PMMA droplet microfluidic device (DMFD) and was shown to be useful in reducing the wetting problem during the generation of aqueous droplets in a perfluorotripropylamine (FC-3283) carrier fluid and could generate stable segmented flows for hours of operation. In the case of PMMA DMFD, oxygen plasma treatment was carried out after the PMMA cover plate was thermally fusion bonded to the PMMA microfluidic chip. Because the appended chemistry to the channel wall created a hydrophobic surface, it will accommodate the use of other carrier fluids that are hydrophobic as well, such as hexadecane or mineral oils. 相似文献
83.
Interaction of Amino Acid Schiff Base Metal Complexes with DNA/BSA Protein and Antibacterial Activity: Spectral Studies,DFT Calculations and Molecular Docking Simulations 下载免费PDF全文
Cu(II), Ni(II) and Zn(II) complexes of (E)‐2‐((2,4‐dihydroxybenzylidene)amino)‐3‐(1H‐indol‐3‐yl)propanoic acid Schiff base ( L ) were synthesized and characterized by various spectral methods. ESI‐MS was used to confirm the structure of synthesized compounds. Molecular geometries of the complexes were predicted by optimizing the structure by DFT/B3LYP method with LANL2DZ basis set in the gas phase. The interaction of the metal complexes with CT‐DNA and BSA protein has been examined by UV‐vis, fluorescence and viscometer titrations reveal that the complexes bind to DNA through intercalation binding mode. The copper complexes exhibit effective cleavage of pUC19 DNA by the oxidative mechanism. The synthesized compounds screened for their antibacterial activities against various bacteria strains exhibit the L and copper complex show potential activity against Pseudomonas aeruginosa and Escherichia coli, respectively. Subsequently, molecular docking studies were performed on to understand the binding of the compounds with DNA, BSA and bacteria. 相似文献
84.
The Fourier Transform Infrared and Raman spectra of the L-Alaninium oxalate (LAO) have been recorded and analyzed. The fundamental vibrational wave numbers intensities of vibrational bands and optimized geometrical parameters of the compound were evaluated using DFT (B3LYP) method with 6-31+G(d,p) basis set. Natural Bond Orbital (NBO) and Natural Population Analysis (NPA) analysis for the LAO compound was carried out. Mulliken population analyses on atomic charges were also calculated. 相似文献
85.
The Molecular Structure of 4-Amino-3-phenylbutanoic acid conformers have been studied in the gas phase. Natural Bond Orbital Analysis (NBO) and Mulliken analysis of atomic charges of 4-Amino-3-phenylbutanoic acid have been performed by DFT level of theory using B3LYP/6-311++G(d,p) basis set. The atomic charges, electronic exchange interaction and charge delocalization of the molecule have been performed by Natural Bond Orbital(NBO) analysis and Natural Population Analysis(NPA) have been constructed at B3LYP/6-311++G(d,p) level. 相似文献
86.
Suppression of Interference Caused by Fragment Brownian Movement through the Utilisation of Fuzzy Formulation 下载免费PDF全文
V. Kathikeyan K. Balamurugan Y.Palin Visu R.Varun Prakash 《Journal of Nonlinear Modeling and Analysis》2024,6(2):228-237
The proposed fuzzy composition-based filtering method aims to remove a presence of fractal Brownian noise in the MR brain images. The fractional Brownian motion (FBM) noise is a continuous time Gaussian processed noise and it''s very difficult to identify the positions and range of noise density level, due to a smoothed noise. The projected fuzzy scheme encloses an equivalent fuzzy interference scheme, a fuzzy average procedure and a fuzzy composition procedure. The noise subtraction scheme has been confirmed to be the finest while the depiction is tainted by means of \textit{fractional Brownian motion}. With an average o/p Peak Signal to Noise Ratio(PSNR) of 37.22 and an average noisy image PSNR of 20.28, the average PSNR rate has improved by 16.94. In addition, the average mean square error (MSE) rate has decreased from 609.48 to 12.33 percent. An experimental result confirms that the fuzzy filtering achieves an outstanding eminence of reinstated images in terms of PSNR and MSE without the assistance of noiseless depiction. 相似文献
87.
Dr. Balamurugan Dhayalan Dr. Yen-Shan Chen Prof. Nelson B. Phillips Mamuni Swain Dr. Nischay K. Rege Ali Mirsalehi Dr. Mark Jarosinski Prof. Faramarz Ismail-Beigi Prof. Norman Metanis Prof. Michael A. Weiss 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(21):4695-4700
Long-acting insulin analogues represent the most prescribed class of therapeutic proteins. An innovative design strategy was recently proposed: diselenide substitution of an external disulfide bridge. This approach exploited the distinctive physicochemical properties of selenocysteine (U). Relative to wild type (WT), Se-insulin[C7UA, C7UB] was reported to be protected from proteolysis by insulin-degrading enzyme (IDE), predicting prolonged activity. Because of this strategy's novelty and potential clinical importance, we sought to validate these findings and test their therapeutic utility in an animal model of diabetes mellitus. Surprisingly, the analogue did not exhibit enhanced stability, and its susceptibility to cleavage by either IDE or a canonical serine protease (glutamyl endopeptidase Glu-C) was similar to WT. Moreover, the analogue's pharmacodynamic profile in rats was not prolonged relative to a rapid-acting clinical analogue (insulin lispro). Although [C7UA, C7UB] does not confer protracted action, nonetheless its comparison to internal diselenide bridges promises to provide broad biophysical insight. 相似文献
88.
Mani Iyer Prasanth Subramanyam Gayathri James Prabhanand Bhaskar Venkateswaran Krishnan Krishnaswamy Balamurugan 《Photochemistry and photobiology》2020,96(1):139-147
Aging, a universal and unique process, occurs both intrinsically (chronological) and extrinsically (photoaging). Ultraviolet-A (UV-A)-mediated stress is a growing health hazard to mankind as it is the major cause of photoaging, which could lead to much damage of skin cells and tissues ranging from tan, burn, or even cancer. The present study focuses on the role of antioxidants and other natural compounds which have been widely used in oral/topical applications to combat and delay the effects of photoaging using model nematode Caenorhabditis elegans. Compounds like green tea extract, naringenin, and naringin, which are known for their antioxidant properties, were able to extend life span and healthspan of the nematode in normal as well as under UV-A-mediated stress conditions. Regulation of both the stress-responsive genes (skn-1 and sir-2.1) and the aging-regulating genes (daf-2 and age-1) was attributable for these conditions. Interestingly, it was observed that these compounds when combined in equal ratios by weight worked synergistically to combat the aging process. Pronounced synergistic effects were observed during UV-A-mediated stress conditions, suggesting that these could be used as potential antiphotoaging compounds which will be of greater significance for health-based research. 相似文献
89.
P. Balamurugan R. Jagan K. Sivakumar 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(3):o109-o113
The title compounds, 2‐chloroanilinium dihydrogen phosphate (2CADHP) and 4‐chloroanilinium dihydrogen phosphate (4CADHP), both C6H7NCl+·H2PO4−, form two‐dimensional supramolecular organic–inorganic hybrid frameworks. In 2CADHP, the dihydrogen phosphate anions form a double‐stranded anionic chain generated parallel to the [010] direction through O—H...O hydrogen bonds, whereas in 4CADHP they form a two‐dimensional supramolecular net extending parallel to the crystallographic (001) plane into which the cations are linked through strong N—H...O hydrogen bonds. 相似文献
90.
A conducting fluorine-doped tin oxide (FTO) electrode, first modified with zinc oxide nanorods (ZnONRs) and subsequently attached with photosynthesized silver nanoparticles (AgNPs), designated as AgNPs/ZnONRs/FTO electrode, was used as an amperometric sensor for the determination of hydrogen peroxide. The first layer (ZnONRs) was obtained by chemical bath deposition (CBD), and was utilized simultaneously as the catalyst for the photoreduction of Ag ions under UV irradiation and as the matrix for the immobilization of AgNPs. The aspect ratio of ZnONRs to be deposited was optimized by controlling the number of their CBDs to render enough surface area for Ag deposition, and the amount of AgNPs to be attached was controlled by adjusting the UV-irradiation time. The immobilized AgNPs showed excellent electrocatalytic response to the reduction of hydrogen peroxide. The resultant amperometric sensor showed 10-fold enhanced sensitivity for the detection of H2O2, compared to that without AgNPs, i.e., only with a layer of ZnONRs. Amperometric determination of H2O2 at −0.55 V gave a limit of detection of 0.9 μM (S/N = 3) and a sensitivity of 152.1 mA M−1 cm−2 up to 0.983 mM, with a response time (steady-state, t95) of 30-40 s. The selectivity of the sensor was investigated against ascorbic acid (AA) and uric acid (UA). Energy dispersive X-ray (EDX) analysis, transmission electron microscopic (TEM) image, X-ray diffraction (XRD) patterns, cyclic voltammetry (CV), and scanning electron microscopic (SEM) images were utilized to characterize the modified electrode. Sensing properties of the modified electrode were studied both by CV and amperometric analysis. 相似文献