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排序方式: 共有995条查询结果,搜索用时 31 毫秒
981.
Harumi Kaga Atsushi Narumi Toshifumi Satoh Takeshi Matsuda Mohd. Sharfuddin Toyoji Kakuchi 《Macromolecular Symposia》2002,181(1):95-100
Coupling reactions of TEMPO-terminated polystyrene (PS-TEMPO) with divinylbenzene were performed in the presence of vinyl saccharides 1 , successfully producing star-shaped polystyrenes with glycoconjugated core 2 . Amphiphilic star-shaped polystyrenes with cores containing saccharide as hydrophilic segments 3 were obtained by the deacetylation of 2 , which exhibited an encapsulation ability toward methyl orange (MO) in chloroform. A positive Cotton effect was observed in the CD spectrum for the MO/ 3 in the adsorption area of MO, indicating that MO existed in a chiral segment, i.e., the glycoconjugated core. 相似文献
982.
Kinetics of the condensation reaction of ninhydrin and the [Ni(II)–histidine]+ complex has been studied spectrophotometrically at pH 5.0, both in aqueous and aqueous–cationic micelles of cetyltrimethylammonium bromide (CTAB). The same product was obtained in both the media. The results obtained in the micellar medium are treated quantitatively in terms of the kinetic pseudo‐phase and Piszkiewicz models. The rate constants, binding constants with the micelles, and the index of cooperativity have been evaluated. On the basis of observed data a possible mechanism has been proposed. The same product was obtained in nonionic micelles of TX‐100, but the studies were hampered due to the appearance of turbidity, whereas anionic micelles of sodium dodecyl sulphate did not catalyze the reaction. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 47–54, 1999 相似文献
983.
Kaushik Kumar Bharadwaj Bijuli Rabha Siddhartha Pati Tanmay Sarkar Bhabesh Kumar Choudhury Arpita Barman Dorothy Bhattacharjya Ankit Srivastava Debabrat Baishya Hisham Atan Edinur Zulhisyam Abdul Kari Noor Haslina Mohd Noor 《Molecules (Basel, Switzerland)》2021,26(21)
Gold nanoparticles (AuNPs) have been widely explored and are well-known for their medical applications. Chemical and physical synthesis methods are a way to make AuNPs. In any case, the hunt for other more ecologically friendly and cost-effective large-scale technologies, such as environmentally friendly biological processes known as green synthesis, has been gaining interest by worldwide researchers. The international focus on green nanotechnology research has resulted in various nanomaterials being used in environmentally and physiologically acceptable applications. Several advantages over conventional physical and chemical synthesis (simple, one-step approach to synthesize, cost-effectiveness, energy efficiency, and biocompatibility) have drawn scientists’ attention to exploring the green synthesis of AuNPs by exploiting plants’ secondary metabolites. Biogenic approaches, mainly the plant-based synthesis of metal nanoparticles, have been chosen as the ideal strategy due to their environmental and in vivo safety, as well as their ease of synthesis. In this review, we reviewed the use of green synthesized AuNPs in the treatment of cancer by utilizing phytochemicals found in plant extracts. This article reviews plant-based methods for producing AuNPs, characterization methods of synthesized AuNPs, and discusses their physiochemical properties. This study also discusses recent breakthroughs and achievements in using green synthesized AuNPs in cancer treatment and different mechanisms of action, such as reactive oxygen species (ROS), mediated mitochondrial dysfunction and caspase activation, leading to apoptosis, etc., for their anticancer and cytotoxic effects. Understanding the mechanisms underlying AuNPs therapeutic efficacy will aid in developing personalized medicines and treatments for cancer as a potential cancer therapeutic strategy. 相似文献
984.
Hui Ming Ong Ahmad Farhan Ahmad Azmi Sze Wei Leong Faridah Abas Enoch Kumar Perimal Ahmad Akira Omar Farouk Daud Ahmad Israf Mohd Roslan Sulaiman 《Molecules (Basel, Switzerland)》2021,26(24)
The present study focuses on the possible involvement of l-arginine-nitric oxide-cGMP-ATP-sensitive K+ channel pathway in the antinociceptive activity of a novel diarylpentanoid analogue, 2-benzoyl-6-(3-bromo-4-hydroxybenzylidene)cyclohexen-1-ol (BBHC) via a chemical nociceptive model in mice. The antinociceptive action of BBHC (1 mg/kg, i.p.) was attenuated by the intraperitoneal pre-treatment of l-arginine (a nitric oxide synthase precursor) and glibenclamide (an ATP-sensitive K+ channel blocker) in acetic acid-induced abdominal constriction tests. Interestingly, BBHC’s antinociception was significantly enhanced by the i.p. pre-treatment of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a selective inhibitor of soluble guanylyl cyclase (p < 0.05). Altogether, these findings suggest that the systemic administration of BBHC is able to establish a significant antinociceptive effect in a mice model of chemically induced pain. BBHC’s antinociception is shown to be mediated by the involvement of l-arginine-nitric oxide-cGMP-ATP-sensitive K+ channel pathway, without any potential sedative or muscle relaxant concerns. 相似文献
985.
986.
Mohd. Sajid Ali Kahkashan Anjum Javed M. Khan Rizwan H. Khan 《Colloids and surfaces. B, Biointerfaces》2011,82(1):258-262
Herein we report our studies carried out on the interaction between IMP and gelatin in aqueous medium at 25 °C using conductimetry, surface tensiometry and circular dichroism (CD) techniques. Both surface tensiometry and conductimetry results indicate that the drug interacts with the gelatin in a surfactant-like manner, i.e., both critical aggregation (cac) and polymer saturation points (psp) were observed. The interaction starts with the formation of a highly surface-active complex as revealed by the lowering of surface tension on the addition of drug to the macromolecule. The decrease in cac on increasing gelatin concentration is an indication of the strong interaction between gelatin and IMP. However, at low concentration of gelatin the interaction was not much strong as exposed by surface tension study, i.e., the cac was not very clear (as with higher gelatin concentrations). As usual, the psp increased on increasing the gelatin concentration and was always higher than the critical micelle concentration of the drug in pure aqueous medium. Using CD measurements the influence of IMP on the secondary structure of gelatin in aqueous solutions was also investigated. CD studies (performed at very low drug concentrations) illustrated that the random coil content of gelatin increases with increasing drug concentration. Free energies of aggregation (ΔGagg) and micellization (ΔGmic) were computed with the help of degrees of micelle ionization obtained from the specific conductivity – [IMP] plots. 相似文献
987.
The kinetics of the oxidative degradation of dipeptide glycyl–glycine (Gly-Gly) by water-soluble colloidal MnO2 in acidic medium has been studied by employing visible spectrophotometer in the aqueous and micellar media at 35 °C. To obtain the rate constants as functions of [Gly-Gly], [MnO2] and [HClO4], pseudo-first-order conditions were maintained in each kinetic run. The first-order-rate is observed with respect to [MnO2], whereas fractional-order-rates are determined in both [Gly-Gly] and [HClO4]. The addition of sodium pyrophosphate and sodium fluoride has composite effects (catalytic and inhibition). The reaction proceeds through the fast adsorption of Gly-Gly on the surface of the colloidal MnO2. The observed results are discussed in terms of Michaelis–Menten/Langmuir–Hinshelwood model. The Arrhenius and Eyring equations are found valid for the reaction over a range of temperatures and different activation parameters have been evaluated. A probable reaction mechanism, in agreement with the observed kinetic results, has been proposed and discussed. The influence of changes in the surfactant concentrations on the observed rate constant is also investigated and the reaction followed the same type of kinetic behavior in micellar media. The pseudo-first-order rate constant (kψ) is found to increase about two-fold with increase in [TX-100]. The catalytic effect of nonionic surfactant TX-100 is explained in terms of the mathematical model proposed by Tuncay et al. 相似文献
988.
Dr. Mohd Waheed Dr. Meshari A. Alsharif Dr. Mohammed Issa Alahmdi Dr. Sayeed Mukhtar Dr. Humaira Parveen 《European journal of organic chemistry》2023,26(14):e202300136
An efficient, environmentally benign and one-pot approach for the synthesis of 2-arylimino-2H-chromenes from 2-hydroxybenzyl alcohols and β-ketothioamides at room temperature under visible light has been developed. The reported reaction conditions were favorable for a wide range of β-ketothioamides afforded good to excellent yields of the respective products. The low cost and air stable Knölker iron catalyst has been employed for the dehydrogenation of 2-hydroxybenzyl alcohols under photolysis that would usually require a higher temperature. 相似文献
989.
Isha Gupta Syeda Nashvia Adin Mohd. Aqil Mohd. Mujeeb Yasmin Sultana 《Biomedical chromatography : BMC》2023,37(1):e5510
The current research work describes the development of a rapid HPLC method for the concurrent detection of pregabalin and piperine in dual drug-loaded nanoformulations. The primary goal was to recognize the chromatographic conditions wherein propitious segregation of the integrants with quality peaks can be attained. An attempt to expound the target analytical profile was made to accomplish this goal, and critical method attributes (CMAs), viz. percentage acetonitrile content, injection volume and pH, which affect critical quality attributes (CQAs), were identified using systemic risk analysis. Box–Behnken design was employed to develop a relationship between CMAs and CQAs, which engenders an analytical design space. Efficient chromatographic separation for pregabalin and piperine was attained using an analytical C18 column and mobile phase comprising acetonitrile–water (pH 6.9; 70:30%, v/v) in an isocratic elution mode with a 1 ml/min flow rate. The elution was descried at an isosbestic wavelength of 221 nm using a photodiode array detector. The International Conference on Harmonization guidelines were adopted for the developed HPLC method. The validated HPLC method can be further utilized for the simultaneous quantification and detection of pregabalin and piperine in other lipid-based nanopharmaceuticals such as polymeric nanoparticles, nanocrystals, solid-lipid nanoparticles, metallic nanoparticles, etc., in in vitro and in vivo studies. 相似文献
990.
Revathy Deivasigamani Nur Nasyifa Mohd Maidin Nur Shahira Abdul Nasir Abdullah Abdulhameed Aminuddin Bin Ahmad Kayani Mohd Ambri Mohamed Muhamad Ramdzan Buyong 《Electrophoresis》2023,44(5-6):573-620
Dielectrophoresis (DEP) bioparticle research has progressed from micro to nano levels. It has proven to be a promising and powerful cell manipulation method with an accurate, quick, inexpensive, and label-free technique for therapeutic purposes. DEP, an electrokinetic phenomenon, induces particle movement as a result of polarization effects in a nonuniform electrical field. This review focuses on current research in the biomedical field that demonstrates a practical approach to DEP in terms of cell separation, trapping, discrimination, and enrichment under the influence of the conductive medium in correlation with bioparticle viability. The current review aims to provide readers with an in-depth knowledge of the fundamental theory and principles of the DEP technique, which is influenced by conductive medium and to identify and demonstrate the biomedical application areas. The high conductivity of physiological fluids presents obstacles and opportunities, followed by bioparticle viability in an electric field elaborated in detail. Finally, the drawbacks of DEP-based systems and the outlook for the future are addressed. This article will aid in advancing technology by bridging the gap between bioscience and engineering. We hope the insights presented in this review will improve cell suspension medium and promote DEP-viable bioparticle manipulation for health-care diagnostics and therapeutics. 相似文献