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21.
Hicham Mahfoz Kotb Mohamad Mahmoud Ahmad Sajid Ali Ansari Tarek S. Kayed Adil Alshoaibi 《Molecules (Basel, Switzerland)》2022,27(3)
In the current study, we report on the dielectric behavior of colossal-dielectric-constant Na1/2La1/2Cu3Ti4O12 (NLCTO) ceramics prepared by mechanochemical synthesis and spark plasma sintering (SPS) at 850 °C, 900 °C, and 925 °C for 10 min. X-ray powder diffraction analysis showed that all the ceramics have a cubic phase. Scanning electron microscope observations revealed an increase in the average grain size from 175 to 300 nm with an increase in the sintering temperature. SPS NLCTO ceramics showed a room-temperature colossal dielectric constant (>103) and a comparatively high dielectric loss (>0.1) over most of the studied frequency range (1 Hz–40 MHz). Two relaxation peaks were observed in the spectra of the electrical modulus and attributed to the response of grain and grain boundary. According to the Nyquist plots of complex impedance, the SPS NLCTO ceramics have semiconductor grains surrounded by electrically resistive grain boundaries. The colossal dielectric constant of SPS NLCTO ceramics was attributed to the internal barrier layer capacitance (IBLC) effect. The high dielectric loss is thought to be due to the low resistivity of the grain boundary of SPS NLCTO. 相似文献
22.
Ramajayam Govindan Mohamed El-Sherbiny Khalid Mohamed Morsy Ibraheem Srinivasan Narasimhan Mohamed EL-Dosoky Mohamed Salama Fazil Ahmad Selvaraj Jayaraman Vishnu Priya Veeraraghavan Srinivasan Vengadassalapathy Surapaneni Krishna Mohan Vidhya Rekha Umapathy Gayathri Rengasamy Shazia Fathima Jaffer Hussain Maheshkumar Poomarimuthu Senthilkumar Kalimuthu 《Molecules (Basel, Switzerland)》2022,27(3)
23.
Ibrahim Mssillou Abdelkrim Agour Aimad Allali Hamza Saghrouchni Mohammed Bourhia Abdelfattah El Moussaoui Ahmad Mohammad Salamatullah Abdulhakeem Alzahrani Mourad A. M. Aboul-Soud John P. Giesy Badiaa Lyoussi Elhoussine Derwich 《Molecules (Basel, Switzerland)》2022,27(7)
Since some synthetic insecticides cause damage to human health, compounds in plants can be viable alternatives to conventional synthetic pesticides. Dittrichia viscosa L. is a perennial Mediterranean plant known to possess biological activities, including insecticidal properties. The chemical composition of an essential oil (EOD) from D. viscosa, as well as its antioxidant, antimicrobial, and insecticidal effects on the cowpea weevil (Callosobruchus maculatus) were determined. Forty-one volatile compounds were identified in EOD, which accounted for 97.5% of its constituents. Bornyl acetate (41%) was a major compound, followed by borneol (9.3%), α-amorphene (6.6%), and caryophyllene oxide (5.7%). EOD exhibited significant antioxidant activity in all tests performed, with an IC50 of 1.30 ± 0.05 mg/mL in the DPPH test and an EC50 equal to 36.0 ± 2.5 mg/mL in the FRAP assay. In the phosphor-molybdenum test, EOD results ranged from 39.81 ± 0.7 to 192.1 ± 0.8 mg AAE/g E. EOD was active on E. coli (9.5 ± 0.5 mm), S. aureus (31.0 ± 1.5 mm), C. albicans (20.4 ± 0.5 mm), and S. cerevisiae (28.0 ± 1.0 mm), with MICs ranging from 0.1 mg/mL to 3.3 mg/mL. We found that 1 µL of EOD caused 97.5 ± 5.0% insect mortality after 96 h in the inhalation test and 60.0 ± 8.3% in the ingestion assay. The median lethal concentration (LC50) was 7.8 ± 0.3 μL EO/L, while the effective concentration in the ingestion test (LC50) was 15.0 ± 2.1 μL EO/L. We found that 20 µL of EOD caused a reduction of more than 91% of C. maculatus laid eggs. 相似文献
24.
25.
Laila Rubab Sumbal Afroz Sajjad Ahmad Saddam Hussain Iram Nawaz Ali Irfan Fozia Batool Katarzyna Kotwica-Mojzych Mariusz Mojzych 《Molecules (Basel, Switzerland)》2022,27(5)
Coumarin is an important six-membered aromatic heterocyclic pharmacophore, widely distributed in natural products and synthetic molecules. The versatile and unique features of coumarin nucleus, in combination with privileged sulfonamide moiety, have enhanced the broad spectrum of biological activities. The research and development of coumarin, sulfonamide-based pharmacology, and medicinal chemistry have become active topics, and attracted the attention of medicinal chemists, pharmacists, and synthetic chemists. Coumarin sulfonamide compounds and analogs as clinical drugs have been used to cure various diseases with high therapeutic potency, which have shown their enormous development value. The diversified and wide array of biological activities such as anticancer, antibacterial, anti-fungal, antioxidant and anti-viral, etc. were displayed by diversified coumarin sulfonamides. The present systematic and comprehensive review in the current developments of synthesis and the medicinal chemistry of coumarin sulfonamide-based scaffolds give a whole range of therapeutics, especially in the field of oncology and carbonic anhydrase inhibitors. In the present review, various synthetic approaches, strategies, and methodologies involving effect of catalysts, the change of substrates, and the employment of various synthetic reaction conditions to obtain high yields is cited. 相似文献
26.
Kulsoom Zahara Yamin Bibi Saadia Masood Sobia Nisa Ahmad Sher Naushad Ali Sunjeet Kumar Abdul Qayyum Waseem Ahmed Rokayya Sami Amina A. M. Al-Mushhin Amani H. Aljahani 《Molecules (Basel, Switzerland)》2022,27(6)
The genus Bidens a member of family Compositae, is widely documented as an ethno-medicinally important genus of plants. In the present study, anticancer potential of three ethno-medicinally important species i.e., B. bipinnata, B. biternata and B. pilosa were tested. For in-vitro evaluation, an MTT (Thiazolyl blue tetrazolium bromide) assay was performed against cervical cancer cells (HeLa), hepatocellular carcinoma (HepG), and adenocarcinoma human alveolar basal epithelial cells (A549). For in vivo evaluation, Artemia salina, Danio rerio, and Caenorhabditis elegans were used. Among all the tested extracts, the ethanol extract of B. biternata appeared to have highest anticancer activity, and the compounds responsible for this activity were identified to be Tris (2,4-di-tert-butylphenyl), 4-hydroxy-2,4′-dimethoxychalcone, and 2,4-di-tert-butylphenol. This is the first report of the isolation of Tris (2,4-di-tert-butylphenyl) phosphate from the genus Bidens and the first report of 4-hydroxy-2,4′-dimethoxychalcone and 2,4-di-tert-butylphenol from B. biternata. Among the isolated compounds, 4-hydroxy-2,4′-dimethoxychalcone showed the highest anticancer activity with an LD50 value of 236.7 µg/mL. Therefore, this compound carries promising potential for being established as a pharmaceutical for chemoprevention and chemotherapy. 相似文献
27.
Xiaoxiao Zheng Rongli Zhai Zihao Zhang Baoqing Zhang Jiangwei Liu Aamir Razaq Muhammad Ashfaq Ahmad Rizwan Raza Muhammad Saleem Syed Rizwan Syed Hassan Mujtaba Jafri Hu Li Raffaello Papadakis 《Molecules (Basel, Switzerland)》2022,27(6)
Composite materials and their applications constitute a hot field of research nowadays due to the fact that they comprise a combination of the unique properties of each component of which they consist. Very often, they exhibit better performance and properties compared to their combined building blocks. Graphene oxide (GO), as the most widely used derivative of graphene, has attracted widespread attention because of its excellent properties. Abundant oxygen-containing functional groups on GO can provide various reactive sites for chemical modification or functionalization of GO, which in turn can be used to develop novel GO-based composites. This review outlines the most recent advances in the field of novel dyes and pigments encompassing GO as a key ingredient or as an important cofactor. The interactions of graphene with other materials/compounds are highlighted. The special structure and unique properties of GO have a great effect on the performance of fabricated hybrid dyes and pigments by enhancing the color performance of dyes, the anticorrosion properties of pigments, the viscosity and rheology of inks, etc., which further expands the applications of dyes and pigments in dyeing, optical elements, solar-thermal energy storage, sensing, coatings, and microelectronics devices. Finally, challenges in the current development as well as the future prospects of GO-based dyes and pigments are also discussed. This review provides a reference for the further exploration of novel dyes and pigments. 相似文献
28.
A stable, passively Q-switched thulium fluoride fiber laser(TFFL) using a multi-walled carbon nanotube(MWCNT)-based saturable absorber(SA) for operation in the S-band region is proposed and demonstrated.The proposed TFFL has a central lasing wavelength of 1486.4 nm and an input power range of 87.1–126.6 m W.The output pulses have a repetition rate and pulse width range of 30.1–40.0 k Hz and 9.0–3.2 μs, respectively,with a maximum pulse energy of 28.9 n J. This is the first time, to the author's knowledge, of the successful demonstration of a passively Q-switched S-band TFFL using an MWCNT-based SA. 相似文献
29.
Reiter P Khoo TL Lauritsen T Lister CJ Seweryniak D Sonzogni AA Ahmad I Amzal N Bhattacharyya P Butler PA Carpenter MP Chewter AJ Cizewski JA Davids CN Ding KY Fotiades N Greene JP Greenlees PT Heinz A Henning WF Herzberg R Janssens RV Jones GD Kondev FG Korten W Leino M 《Physical review letters》2000,84(16):3542-3545
The entry distribution in angular momentum and excitation energy for the formation of 254No has been measured after the 208Pb(48Ca,2n) reaction at 215 and 219 MeV. This nucleus is populated up to spin 22Planck's over 2pi and excitation energy greater, similar6 MeV above the yrast line, with the half-maximum points of the energy distributions at approximately 5 MeV for spins between 12Planck's over 2pi and 22Planck's over 2pi. This suggests that the fission barrier is greater, similar5 MeV and that the shell-correction energy persists to high spin. 相似文献
30.
Water vapor adsorption onto activated carbons prepared from cattle manure compost (CMC) 总被引:1,自引:0,他引:1
Qingrong Qian Satoshi Sunohara Muhammad Abbas Ahmad Zaini Hideki Tatsumoto 《Applied Surface Science》2008,254(15):4868-4874
Activated carbons were prepared from cattle manure compost (CMC) using zinc chloride activation. The structural and surface chemical characteristics of CMC-based activated carbons were determined by N2 adsorption-desorption and Boehm titration, respectively. The water vapor adsorption properties of the prepared activated carbons with various pore structure and surface nature were examined, and the mechanism of water adsorbed onto activated carbon was also discussed. The results show that the adsorption of water vapor on carbons begins at specific active sites at low relative humidity (RH), followed by micropore filling at medium RH through the formation of pentamer cluster of water molecules in the narrow micropores. The water vapor adsorption capacity of activated carbon is predominantly dependent on its pore volume and surface area. Although capillary condensation is not the mechanism for water adsorption onto activated carbon, water can adsorb on narrow mesopore to some extent. 相似文献