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排序方式: 共有239条查询结果,搜索用时 15 毫秒
1.
Aik Sian Tan Jaymeer Singh Nurul Syafiqah Rezali Musthahimah Muhamad Nik Nur Syazni Nik Mohamed Kamal Yvan Six Mohamad Nurul Azmi 《Molecules (Basel, Switzerland)》2022,27(17)
The Heck cross-coupling reaction is a well-established chemical tool for the synthesis of unsaturated compounds by formation of a new C-C bond. In this study, 1,3-diarylpropene derivatives, designed as structural analogues of stilbenoids and dihydrostilbenoids, were synthesised by the palladium-catalysed reactions of 2-amidoiodobenzene derivatives with either estragole or eugenol. The products were obtained with high (E) stereoselectivity but as two regioisomers. The ratios of isomers were found to be dependent on the nature of the allylbenzene partner and were rationalised by electronic effects exercising a determining influence in the β-hydride elimination step. In addition, the cytotoxic effects of all the Heck reaction products were evaluated against MCF-7 and MDA-MB-231 human breast cancer cells, with unpromising results. Among all, compound 7d exhibited weak cytotoxic activity towards MCF-7 cell lines with IC50 values of 47.92 µM in comparison with tamoxifen and was considered to have general toxicity (SI value < 2). 相似文献
2.
Wafa Arif Nosheen Fatima Rana Iqra Saleem Tahreem Tanweer Muhammad Jawad Khan Sohad Abdulkaleg Alshareef Huda M. Sheikh Fatima S. Alaryani Manal Othman AL-Kattan Hanan Ali Alatawi Farid Menaa Aroosa Younis Nadeem 《Molecules (Basel, Switzerland)》2022,27(21)
Resin composites have been widely used in dental restoration. However, polymerization shrinkage and resultant bacterial microleakage are major limitations that may lead to secondary caries. To overcome this, a new type of antibacterial resin composite containing ciprofloxacin-loaded silver nanoparticles (CIP-AgNPs) were synthesized. The chemical reduction approach successfully produced CIP-AgNPs, as demonstrated by FTIR, zeta potential, scanning electron microscopy, and ultraviolet-visible (UV-vis) spectroscopy. CIP-AgNPs were added to resin composites and the antibacterial activity of the dental composite discs were realized against Enterococcus faecalis, Streptococcus mutans, and the Saliva microcosm. The biocompatibility of modified resin composites was assessed and mechanical testing of modified dental composites was also performed. The results indicated that the antibacterial activity and compressive strength of resin composites containing CIP-AgNPs were enhanced compared to the control group. They were also biocompatible when compared to resin composites containing AgNPs. In short, these results established strong ground application for CIP-AgNP-modified dental composite resins. 相似文献
3.
H. M. Noor ul Huda Khan Asghar Yi Tan Shuang Shi Dachuan Jiang Shiqiang Qin Jiao Liao Shutao Wen Wei Dong Yao Liu 《Applied Physics A: Materials Science & Processing》2014,115(3):753-757
Small amounts of multicrystalline silicon were melted in an electron beam furnace in different experimental conditions in order to investigate the oxygen evaporation behavior during the electron beam melting (EBM) process. The oxygen content level before and after EBM was determined by secondary ion mass spectroscopy. The oxygen content was reduced from 6.177 to 1.629 ppmw when silicon was melted completely at 15 kW with removal efficiency up to 73.6 %. After that, it decreased continually to <0.0517 ppmw when the refining time exceeded 600 s with a removal efficiency of more than 99.08 %. During the melting process, the evaporation rate of silicon is 1.10 × 10?5 kg/s. The loss of silicon could be reduced up to 1.7 % during oxygen removal process to a desirable figure, indicating EBM is an effective method to remove oxygen from silicon and decrease the loss of silicon. 相似文献
4.
5.
Osman Ayop Mohamad Kamal A. Rahim Noor Asniza Murad Huda A. Majid 《Applied Physics A: Materials Science & Processing》2014,117(2):651-656
This paper presents the analysis of circular ring metamaterial absorber with the existing of copper lines. The structure is designed using lossy FR4 substrate with thin copper layers. The circular ring shape with copper lines is printed on the top surface of FR4 substrate, while at the bottom surface is printed with full copper ground plane. Parametric study is done to investigate the effect of copper lines on the resonance frequency. From the simulation, the circular ring metamaterial absorber with vertical copper lines can resonates at lower frequency, but this structure is polarized sensitive. This drawback can be improved by adding horizontal copper lines together with the vertical copper lines. The circular ring structure with vertical and horizontal copper lines is not only polarization insensitive, but it can works at wide operating angle of incident waves. 相似文献
6.
Leslie W. Deady Andrew B. Hughes Indumathy B. Mahadevan Nurul H. Quazi Leann M. Tilley 《合成通讯》2013,43(5):803-820
The synthesis of fluorescent 2,10-derivatives of the title chromophore are described. The substituents contain amino-reactive N-hydroxysuccinimde ester and thiol-reactive iodoacetamide groups for attachment to biomolecules. A phosphate derivative was also prepared as an enzyme substrate. 相似文献
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8.
V. L. Y. Loke G. M. Huda E. U. Donev V. Schmidt J. T. Hastings M. Pinar Mengüç T. Wriedt 《Applied physics. B, Lasers and optics》2014,115(2):237-246
We investigate the plasmonic response of gold nanospheres calculated using discrete dipole approximation validated against the results from other discretization methods, namely the finite-difference time-domain method and the finite-element methods. Comparisons are also made with calculations from analytical methods such as the Mie solution and the null-field method with discrete sources. We consider the nanoparticle interacting with the incident field both in free space and sitting on a planar substrate. In the latter case, discrete dipole approximation with surface interaction is used; this includes the interaction with the ‘image dipoles’ using Sommerfeld integration. 相似文献
9.
10.
Stereoselective route to tricyclo[5.3.1.01,5]undecane and bicyclo[4.2.0]octane ring systems present in the molecular structure of tricycloillicinone, cedrenoids and endiandric acid, elysiapyrones, respectively, is described. A tandem oxidative dearomatization of o-hydroxymethylphenol, π4s+π2s cycloaddition, reactivity modulation in excited state and ring-closing metathesis are the key features of our approach. 相似文献