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排序方式: 共有809条查询结果,搜索用时 15 毫秒
801.
802.
Flat H-terminated Si(111) substrates modified with alkyl monolayers terminated with hydrophobic and hydrophilic functional groups were prepared using known surface functionalization methods and characterized by FTIR, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The surfaces were then used for the study of non-specific binding of proteins from complex mixtures (using standard mixture of proteins with average molecular weight approximately 6-66 kDa) by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Protein adsorption on these surfaces (following on-probe fractionation of the mixture) was found to be dependent on the nature of surface functional groups, and nature and pH of rinsing solutions used. The results obtained in this work demonstrate that simple silicon-based surface modifications can be effective for direct analysis of complex mixtures by MALDI-MS. Preliminary results obtained using similarly functionalized porous silicon substrates proved that such substrates are (due to their increased surface areas) better performing than flat silicon. 相似文献
803.
Lugo-Mas P Dey A Xu L Davin SD Benedict J Kaminsky W Hodgson KO Hedman B Solomon EI Kovacs JA 《Journal of the American Chemical Society》2006,128(34):11211-11221
804.
Photonic crystal slab cavities were investigated for increased light-matter interaction based on selective placement of sublattice hole sized defect holes inside L3 cavities. A multiple-hole defect (MHD) consisting of three defect holes placed in the regions of highest cavity mode field intensity were demonstrated through finite-difference time-domain simulations and experiments to exhibit the strongest light-matter interaction without introducing significant scattering losses. Compared to an L3 cavity without defect holes, these strategically designed three-hole MHD cavities presented higher quality factor and more than double the resonance wavelength shift upon exposure to a thin oxide and two small chemical molecules. 相似文献
805.
Fuad Fares Soliman Khatib Jacob Vaya Lital Sharvit Einav Eizenberg Solomon Wasser 《Molecules (Basel, Switzerland)》2022,27(9)
The aim of the present study was to identify the structure of active compounds in Cyathus stratus that previously demonstrated anti-pancreatic cancer activity. The active compounds were purified from a crude extract by a series of RP-18 preparative chromatography using homemade octadecyl silica gel column. HPLC injection of the crude extract revealed a chromatogram with three main peaks with retention times (RT) 15.6, 18.2, and 22.5 min. Each fraction that exhibited promising activity in vitro was further separated using various available chromatographic techniques. The purified compound with the ultimate anti-cancer activity appeared at RT of 15.8 in the HPLC chromatogram with more than 90% purity. The main peak at the mass spectra appeared at m/z = 446.2304 with the calculated molecular formula of C25H34O7. One- and two-dimensional NMR analyses indicated that the structure of the active molecule (peak 15.8 min in HPLC) was identified as striatal C. Exposure of human pancreatic cancer cells to purified striatal C resulted in induction of apoptosis. Further studies are needed in order to develop a method for the synthesis of striatal in order to use it in clinical studies for treatment of cancer. 相似文献
806.
Ermias Mergia Terefe Faith Apolot Okalebo Solomon Derese Moses K. Langat Eduard Mas-Claret Kamal Ahmad Qureshi Mariusz Jaremko Joseph Muriuki 《Molecules (Basel, Switzerland)》2022,27(20)
In recent years, elucidation of novel anti-HIV bioactive compounds from natural products is gaining importance rapidly, not only from the research and publications, but also from controlled clinical studies. Here we report three new anti-HIV eudesmane-type sesquiterpenes, 5β-Hydroxy-8α-methoxy eudesm-7(11)-en-12,8-olide (1), 5β,8α-Dihydroxy eudesm-7(11)-en-12,8-olide (2) and 5β-Hydroxy-8H-β-eudesm-7(11)-en-12,8-olide (3). These are trivially named ermiasolide A-C and were isolated from the bark of Croton megalocarpus. 5β-Hydroxy-8α-methoxy eudesm-7(11)-en-12,8-olide (1), showed the highest anti-HIV activity by inhibiting 93% of the viral replication with an IC50 = 0.002 µg/mL. On the other hand, 5β-Hydroxy-8H-β-eudesm-7(11)-en-12,8-olide (3) and 5β,8α-dihydroxy eudesm-7(11)-en-12,8-olide (2), inhibited viral replication by 77.5% at IC50 = 0.04 µg/mL and 69.5% at IC50 = 0.002 µg/mL, respectively. Molecular docking studies showed that the proposed mechanism of action leading to these results is through the inhibition of HIV-protease. 相似文献
807.
Solomon Bekele Zegeye Habtu Zegeye Mengstu Goa Sangago Oganeditse A. Boikanyo Sebsibe Teferi Woldeamanuel 《Mathematical Methods in the Applied Sciences》2023,46(2):2884-2905
In this paper, we propose an inertial algorithm for solving split equality of monotone inclusion and -fixed point of Bregman relatively -nonexpansive mapping problems in reflexive real Banach spaces. Using the Bregman distance function, we prove a strong convergence theorem for the algorithm produced by the method in real reflexive Banach spaces. In addition, we provide some applications of our method and give numerical results to demonstrate the applicability and efficiency of the proposed method. 相似文献
808.
Simmi Abrol Peter A. Kambouris Mark G. Looney David H. Solomon 《Macromolecular rapid communications》1997,18(9):755-760
Microgels which are soluble crosslinked polymer networks have been prepared using the nitroxide living free radical polymerization methodology. When heated in the presence of tert-butylstyrene and 1,4-divinylbenzene, the alkoxyamine 1 derived from 2,2′-azoisobutyronitrile (AIBN) afforded a high molecular weight soluble polymer which was shown by size exclusion chromatography in conjunction with an on-line multi angle laser light scattering (MALLS) detector to have microgel properties. 相似文献
809.