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排序方式: 共有158条查询结果,搜索用时 15 毫秒
41.
Kawther M Musthaf Azura Hamzah Ooi Wei Ling Ahmad Haziq Aiman Rosol Norliza Mohame Sulaiman Wadi Harun 《光电子快报》2024,20(6):321-329
42.
Fakhry Abdel-Aziz El-Bassiouny 《中国化学》1991,9(4):360-364
α- and β-Acetylnaphthalenes condensed with dimethyl β,β-dimethyl glutarate in the presence of sodium hydride to give the corresponding half-esters, the E-isomers 2a and 2b being predominant. The structure and configuration of the half-esters were characterized by chemical and spectroscopic means. 相似文献
43.
44.
Tasneem Mokhtar Radwan Maher Abdel-Aziz El-Hashash Ashraf Abdel-Hamid Farouk Wasfy Suzan Abdelhalim Abdallah 《Journal of heterocyclic chemistry》2020,57(3):1111-1122
Heterocyclic compounds with different heterocycle moieties, namely benzoxazinone, benzimidazole, quinazolinone, and benzofuranone heterocyclic rings, were synthesized, characterized, and evaluated for their anticancer activity against human hepatocellular carcinoma cell line (HepG2) using sulforhodamine B (SRB) and dimethylthiazol-diphenyltetrazolium bromide (MTT) assays. Also, their cytotoxic activities were tested against human epithelioid carcinoma (Hela) cell line in comparison with normal cell, amniotic epithelial (WISH) cell line, as an in vitro toxicity estimation model. The results showed clearly that 2-(2-benzyl-4-oxoquinazolin-3(4H)-yl)acetohydrazide 4 is the most potent antioxidant and anticancer agents. Although, 3-amino-2-benzylquinazolin-4(3H)-one 5 is less potent anticancer agent against Hela but it is more safe against normal cell (WISH). 相似文献
45.
Krishnan Kumar Elias Saion M. K. Halimah Yap CK Muhd Suhaimi Hamzah 《Journal of Radioanalytical and Nuclear Chemistry》2014,301(3):667-676
A study is carried out on the concentrations of rare earth element (REE) elements present in surface mangrove sediments from 10 locations throughout west coast Malaysia. In carrying out the analysis, the best and most convenient method being the instrumental neutron activation analysis (INAA). Samples were obtained, dried, crushed to powdery form and samples prepared for INAA. All the samples for analysis were weighted approximately 150 mg for short irradiation and 200 mg for long irradiation time. As calibration and quality control procedures, blank samples, standard reference material SL-1 were then irradiated with thermal neutron flux of 4 × 1012 cm?2 s?1 at the MINT TRIGA Mark II research reactor which operated at 750 kW by using a pneumatic transport facility. The REE elements of surface sediment samples in this study are Dy, Sm, Eu,Yb, Lu, Tb, La and Ce. It was found that the level of concentrations of all the REE elements varies in the range (0.35–117.4 mg/kg). The geochemical behavior of REEs in surface sediments and normalized pattern (chondrite and shale) has been studied. The degree of sediments contaminations were computed using an enrichment factor. The results showed that the enrichment factor varied in the range (0.75–6.75). 相似文献
46.
A. Hamzah M. C. Paul S. W. Harun N. A. D. Huri A. Lokman M. Pal S. Das S. K. Bhadra H. Ahmad S. Yoo M. P. Kalita A. J. Boyland J. K. Sahu 《Laser Physics》2011,21(1):176-179
A compact Erbium-doped fiber laser (EDFL) operating in L-band region is demonstrated using a fabricated Erbium-doped Zirconia fiber (EDZF) for the first time. The fiber is fabricated by combining Zr and Al to achieve the maximum Erbium ion concentration of 4320 wt ppm. By using a fiber Bragg grating (FBG) in a ring configuration, the laser operates at 1579.6 nm with a slope efficiency of 13.6% and the threshold pump power of 25.1 mW. The lasing wavelength is obtained at Bragg wavelength with an output power of 13 dBm and a 3 dB spectral width of 0.02 nm using a piece of 2 m long EDZF in conjunction with 120 mW of 1480 nm pump power. 相似文献
47.
Abdel-Aziz S. El-ahl 《合成通讯》2013,43(12):2223-2231
The reaction of 6-aminouracils 2a, b with 2-oxoindolin-3-ylideneacetophenones 1a-h afforded Pyrimido[5,4:5', 6'] pyrido-[2, 3-b] indole- 2,4-diones 3 a-k via a regiospecific Michael addition, followed by cyclization. Alternatively, the reaction of 2a with 2-oxoindolin-3-ylidenemalononitriles 6a, b gave rise to regiospecific formation of spiro indolin-2-one-3, 5'-pyrido[2,3-d]pyrimidines 7a,b. 相似文献
48.
Zurina Shaameri Sharifah Hidayah Sharif Ali Mohd Fazli Mohamat Bohari M. Yamin Ahmad Sazali Hamzah 《Journal of heterocyclic chemistry》2013,50(2):320-325
A brief and efficient approach for the synthesis of (±)‐5‐benzyl‐4‐hydroxy‐2‐pyrrolidine ( 1 ) from phenylalanine racemate is described. The key step is the stereocontrolled reduction of the keto functionality of benzylated pyrrolidinone intermediate ( 6 ) via sodium borohydride in carboxylic acid medium furnishing both (R,R)‐ and (S,S)‐configured diastereomers. The natural (R,R) enantiomer ( 2 ), however, crystallized out from its racemic mixture. Structure of 2 was confirmed by NMR, IR, elemental analyzer, and single crystal X‐ray crystallographic techniques. 相似文献
49.
Endothelial cell dysfunction is considered to be one of the major causes of vascular complications in diabetes. Polyphenols are known as potent antioxidants that can contribute to the prevention of diabetes. Corn silk has been reported to contain polyphenols and has been used in folk medicine in China for the treatment of diabetes. The present study aims to investigate the potential protective role of the phenolic-rich fraction of corn silk (PRF) against injuries to vascular endothelial cells under high glucose conditions in vitro and in vivo. The protective effect of PRF from high glucose toxicity was investigated using human umbilical vein endothelial cells (HUVECs). The protective effect of PRF was subsequently evaluated by using in vivo methods in streptozotocin (STZ)-induced diabetic rats. Results showed that the PRF significantly reduced the cytotoxicity of glucose by restoring cell viability in a dose-dependent manner. PRF was also able to prevent the histological changes in the aorta of STZ-induced diabetic rats. Results suggested that PRF might have a beneficial effect on diabetic patients and may help to prevent the development and progression of diabetic complications such as diabetic nephropathy and atherosclerosis. 相似文献
50.
Hamad M. Alkahtani Amer Alhaj Zen Ahmad J. Obaidullah Mohammed M. Alanazi Abdulrahman A. Almehizia Siddique Akber Ansari Fadilah Sfouq Aleanizy Fulwah Yahya Alqahtani Rana M. Aldossari Raghad Abdullah Algamdi Lamees S. Al-Rasheed Sami G. Abdel-Hamided Alaa A.-M. Abdel-Aziz Adel S. El-Azab 《Molecules (Basel, Switzerland)》2023,28(1)