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61.
A single chip optical receiver with an integrated large-diameter photodiode, transimpedance amplifier, two stages active equalizer, post amplifier and 50 Ω driver is used for gigabit transmission over PMMA step plastic optical fiber (SI-POF). The large-diameter photodiode with an antireflection coating optimized for red light. The integrated equalizer enables the presented optical receiver to reach 1 Gbit/s over 50 m SI-POF at bit error ratio of 10− 6. An error free (< 10− 9) 1 Gbit/s data rate over 40 m standard PMMA step-index plastic optical fiber is also achieved. 相似文献
62.
Cyclization of 2‐furan‐2‐yl‐4‐mercapto‐6‐methylpyrimidine‐5‐carbonitrile 1 with ethyl chloroacetate gave o‐aminoester thienopyrimidine derivative 3 , which was reacted with a variety of reagents to give a series of novel thienopyrimidines including tetrazolyl thienopyrimidine, pyrrolylthienopyrimidine, pyrimidothienotriazine, and thienodipyrimidines. Some of the synthesized compounds were tested for their antibacterial activities against Gram‐positive and Gram‐negative bacteria. 相似文献
63.
Prof. Dr. Farid A. Badria Saleh Atef Prof. Dr. Abdullah Mohammed Al-Majid M. Ali Dr. Yaseen A. M. M. Elshaier Dr. Hazem A. Ghabbour Mohammad Shahidul Islam Dr. Assem Barakat 《ChemistryOpen》2019,8(10):1288-1297
The Michael addition reaction of barbituric acid with chalcones incorporating the indole scaffold was achieved by using a highly efficient bimetallic Iron–palladium catalyst in the presence of acetylacetone (acac). This catalytic approach produced the desired products in a simple operation and low catalyst loading with acceptable yield of the new hybrids. All tested compounds were subjected for biological activity on α-glucosidase and α-amylase. The results revealed that all synthesized compounds exhibited very good activity against both enzymes when compared to positive control (acarbose). Moreover, compound 5o showed the best activity whereas its IC50 (μM) are 13.02+0.01 and 21.71+0.82 for α-glucosidase and α-amylase respectively. Both compounds 5o and 5l exhibited high similarity in binding mode and pose with amylase protein (4UAC). The obtained data may be used for developing potential hypoglycemic agents. 相似文献
64.
Robrecht M. A. Vergauwe Anoop Thomas Kalaivanan Nagarajan Atef Shalabney Jino George Thibault Chervy Marcus Seidel Eloïse Devaux Vladimir Torbeev Thomas W. Ebbesen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(43):15468-15472
Vibrational strong coupling (VSC) has recently emerged as a completely new tool for influencing chemical reactivity. It harnesses electromagnetic vacuum fluctuations through the creation of hybrid states of light and matter, called polaritonic states, in an optical cavity resonant to a molecular absorption band. Here, we investigate the effect of vibrational strong coupling of water on the enzymatic activity of pepsin, where a water molecule is directly involved in the enzyme's chemical mechanism. We observe an approximately 4.5‐fold decrease of the apparent second‐order rate constant kcat/Km when coupling the water stretching vibration, whereas no effect was detected for the strong coupling of the bending vibration. The possibility of modifying enzymatic activity by coupling water demonstrates the potential of VSC as a new tool to study biochemical reactivity. 相似文献
65.
Al-Wasidi A. S. Al-Jafshar N. M. Al-Anazi A. M. Refat M. S. Ismail L. A. Al-Omar M. A. Naglah A. M. Kalmouch Atef 《Russian Journal of General Chemistry》2019,89(10):2121-2128
Russian Journal of General Chemistry - Mixed ligand vanadyl(II) complexes of orotic acid and six different amino acids (isoleucine, threonine, proline, phenylalanine, lysine, and glutamine) have... 相似文献
66.
Dr. Atef Shalabney Dr. Jino George Dr. Hidefumi Hiura Dr. James A. Hutchison Dr. Cyriaque Genet Prof. Petra Hellwig Prof. Thomas W. Ebbesen 《Angewandte Chemie (International ed. in English)》2015,54(27):7971-7975
Ground‐state molecular vibrations can be hybridized through strong coupling with the vacuum field of a cavity optical mode in the infrared region, leading to the formation of two new coherent vibro‐polariton states. The spontaneous Raman scattering from such hybridized light–matter states was studied, showing that the collective Rabi splitting occurs at the level of a single selected bond. Moreover, the coherent nature of the vibro‐polariton states boosts the Raman scattering cross‐section by two to three orders of magnitude, revealing a new enhancement mechanism as a result of vibrational strong coupling. This observation has fundamental consequences for the understanding of light‐molecule strong coupling and for molecular science. 相似文献
67.
(3R,4aR,5S,6R)-6-Hydroxy-5-methylramulosin (1) was isolated from a culture of a sterile mycelium, which was derived from the green alga, Codium fragile, along with (-)-5-methylmellein (2), (-)-5-hydroxymethylmellein (3), and (-)-(3R,4R)-cis-4-hydroxy-5-methylmellein (4). The absolute configuration of 1 was determined by the NMR data along with the lactone sector rule by circular dichroism (CD). Compound 1 exhibited moderate cytotoxic activity against HeLa cells. 相似文献
68.
Monodictyquinone A: a new antimicrobial anthraquinone from a sea urchin-derived fungus Monodictys sp
El-Beih AA Kawabata T Koimaru K Ohta T Tsukamoto S 《Chemical & pharmaceutical bulletin》2007,55(7):1097-1098
A new antimicrobial anthraquinone, 1,8-dihydroxy-2-methoxy-6-methylanthraquinone, monodictyquinone A (1), was isolated from a culture of a marine-derived fungus of the genus Monodictys which was isolated from the sea urchin, Anthocidaris crassispina, along with three known compounds, pachybasin (2), chrysophanol (3), and emodin (4). 相似文献
69.
70.
Ahmed Bakr Abdelwahab Eslam Reda El-Sawy Atef G. Hanna Denyse Bagrel Gilbert Kirsch 《Molecules (Basel, Switzerland)》2022,27(8)
Cdc25 phosphatases have been considered promising targets for anticancer development due to the correlation of their overexpression with a wide variety of cancers. In the last two decades, the interest in this subject has considerably increased and many publications have been launched concerning this issue. An overview is constructed based on data analysis of the results of the previous publications covering the years from 1992 to 2021. Thus, the main objective of the current review is to report the chemical structures of Cdc25s inhibitors and answer the question, how to design an inhibitor with better efficacy and lower toxicity? 相似文献