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81.
Wajheeba Khan Naeem Khan Nargis Jamila Rehana Masood Aaliya Minhaz Farhat Amin Amir Atlas Umar Nishan 《Saudi Journal of Biological Sciences》2022,29(2):894-904
Rhus javanica (Anacardiaceae) containing abundant glucopyranosidal constituents, is traditionally used to treat gastric and duodenal ulcer, dysentery, and diarrhea. Rumex hastatus (Polygonaceae) widely distributed in Pakistan, has traditional importance in treating wound healing, jaundice, rheumatism, and skin diseases. Callistemon viminalis (Myrtaceae), a rich source of essential oils, saponins, triterpenoids, phloroglucinols, and flavonoids is used in industries, perfumes, nutrition, and cosmetics. Taking the importance of the subject plants, this study is designed to synthesize silver nanoparticles via aqueous extracts of R. javanica (RJAgNPs), R. hastatus (RHAgNPs), and C. viminalis (CVAgNPs). Synthesis, surface, and sizes of silver nanoparticles (AgNPs) were confirmed using spectroscopic techniques including ultraviolet–visible (UV–Vis), Fourier transform-infrared (FT-IR), and scanning electron microscopy (SEM). AgNPs were produced in ratios 1:15, 1:16, and 1:9 and inferred via appearance of a sharp surface plasmon resonance (SPR) absorption peak (400–435 nm), which represented well-defined, stable, and spherical AgNPs. From SEM analysis, the sizes of RJAgNPs, RHAgNPs, and CVAgNPs were found to be 67 nm, 61 nm, and 55 nm, respectively. The synthesized AgNPs exhibited potential free radical scavenging, antibacterial, and catalytic properties in degradation of dyes including Congo red, methylene blue, methyl orange, rhodamine B, ortho and para-nitrophenols, and several food colours. Hence, the subject AgNPs in the current study might display promising role in drug development and remediation of environmental/industrial effluents. 相似文献
82.
Mohamed T. El-Saadony Ahmed M. Saad Hend A. Elakkad Amira M. El-Tahan Omniah A. Alshahrani Mashaeal S. Alshilawi Hanan El-Sayed Shimaa A. Amin Alshaymaa I. Ahmed 《Saudi Journal of Biological Sciences》2022,29(1):346
This work aims to enhance the flavor of functional cucumber juice using herbal extracts of peppermint, basil, lavender, and lemongrass ethanolic extracts and extend its lifetime by controlling the chemical and microbial fluctuations. Cucumber juices were processed as; non-supplemented (J-Con), J-PME, J-BE, J-LE, and J-LEE supplemented with peppermint, basil, lavender, and lemongrass ethanolic extracts, respectively. Peppermint extract was significantly scavenged 88% of DPPH radicals and inhibited the growth of tested gram-positive, gram-negative bacteria and fungi followed by the lemongrass extract. The antioxidant activity of cucumber juices increased due to polyphenols and aroma compounds in the added extracts. However, the antioxidant content was decreased after two months of storage at 4 °C, due to the decrease in polyphenols. The flavor compounds were determined using GC mass, wherein hydrocarbons, acids, alcohols, and carbonyl compounds were the main aroma contents in cucumber juices, and their contents decreased with storage time. Peppermint and lemongrass extracts were significantly (p ≤ 0.05) increased the whiteness of J-PME, and J-LEE, respectively. The highest score of flavor and taste was observed in J-PME that scored 8.3 based on panelists'' reports followed by J-LEE. The PME was significantly maintained 91% of the odor and color of J-PME as compared to other juices. 相似文献
83.
Plasmonics - We study two-dimensional (2D) hole arrays drilled into a perfect conductor slab covered with a graphene sheet. Such arrays support the extraordinary transmission of electromagnetic... 相似文献
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Sharma P Steinbach PJ Sharma M Amin ND Barchi JJ Pant HC 《The Journal of biological chemistry》1999,274(14):9600-9606
Cyclin-dependent kinase 5 (CDK5), unlike other CDKs, is active only in neuronal cells where its neuron-specific activator p35 is present. However, it phosphorylates serines/threonines in S/TPXK/R-type motifs like other CDKs. The tail portion of neurofilament-H contains more than 50 KSP repeats, and CDK5 has been shown to phosphorylate S/T specifically only in KS/TPXK motifs, indicating highly specific interactions in substrate recognition. CDKs have been shown to have a high preference for a basic residue (lysine or arginine) as the n+3 residue, n being the location in the primary sequence of a phosphoacceptor serine or threonine. Because of the lack of a crystal structure of a CDK-substrate complex, the structural basis for this specific interaction is unknown. We have used site-directed mutagenesis ("charged to alanine") and molecular modeling techniques to probe the recognition interactions for substrate peptide (PKTPKKAKKL) derived from histone H1 docked in the active site of CDK5. The experimental data and computer simulations suggest that Asp86 and Asp91 are key residues that interact with the lysines at positions n+2 and/or n+3 of the substrates. 相似文献
87.
Tetracycline up-regulates COX-2 expression and prostaglandin E2 production independent of its effect on nitric oxide 总被引:4,自引:0,他引:4
Attur MG Patel RN Patel PD Abramson SB Amin AR 《Journal of immunology (Baltimore, Md. : 1950)》1999,162(6):3160-3167
Tetracyclines (doxycycline and minocycline) augmented (one- to twofold) the PGE2 production in human osteoarthritis-affected cartilage (in the presence or absence of cytokines and endotoxin) in ex vivo conditions. Similarly, bovine chondrocytes stimulated with LPS showed (one- to fivefold) an increase in PGE2 accumulation in the presence of doxycycline. This effect was observed at drug concentrations that did not affect nitric oxide (NO) production. In murine macrophages (RAW 264.7) stimulated with LPS, tetracyclines inhibited NO release and increased PGE2 production. Tetracycline(s) and L-N-monomethylarginine (L-NMMA) (NO synthase inhibitor) showed an additive effect on inhibition of NO and PGE2 accumulation, thereby uncoupling the effects of tetracyclines on NO and PGE2 production. The enhancement of PGE2 production in RAW 264.7 cells by tetracyclines was accompanied by the accumulation of both cyclooxygenase (COX)-2 mRNA and cytosolic COX-2 protein. In contrast to tetracyclines, L-NMMA at low concentrations (< or = 100 microM) inhibited the spontaneous release of No in osteoarthritis-affected explants and LPS-stimulated macrophages but had no significant effect on the PGE2 production. At higher concentrations, L-NMMA (500 microM) inhibited NO release but augmented PGE2 production. This study indicates a novel mechanism of action of tetracyclines to augment the expression of COX-2 and PGE2 production, an effect that is independent of endogenous concentration of NO. 相似文献
88.
Milking of microalgae 总被引:6,自引:0,他引:6
The low productivity of algal cultures in the production of high-value compounds is the most significant bottleneck for commercialization of this technology. Cultures in which cell mass is reused for continuous production are proposed as a solution to overcome this problem. Recently, a method was developed in which beta-carotene was harvested from the microalga Dunaliella salina grown in a two-phase bioreactor. This raises the question of whether this technique could also be used in the mass production of secondary metabolites. Understanding the mechanism of the milking process and its relationship to the product formation pathway should reveal whether other products can be milked from various species of microalgae. 相似文献
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