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排序方式: 共有157条查询结果,搜索用时 15 毫秒
1.
Sreenivasa Nayak Meghashyama P. Bhat A.C. Udayashankar T.R. Lakshmeesha Nagaraja Geetha Sudisha Jogaiah 《应用有机金属化学》2020,34(4):e5567
Dillenia indica L. is a traditional medicinal plant well known for its ability to cure various human diseases. In the current study, silver nanoparticles have been synthesized by simple and eco-friendly method using Dillenia indica extract. The green synthesized nanoparticles were characterized by Fourier transform infrared (FTIR), UV–visible spectroscopy, Atomic force microscopy (AFM), High-resolution transmission electron microscopy (HR-TEM), Zeta Potential and Size Distribution. UV–visible and FTIR spectra, AFM, HR-TEM and Zeta Potential readings and size distribution conformed that the synthesized silver particles were in the size of nano. The green synthesized silver nanoparticles were subjected for antibacterial activity against Gram-positive bacteria Enterococcus faecalis and Gram-negative bacteria Escherichia coli by agar well diffusion method. The synthesized AgNPs exhibited significant inhibition of 27 and 16 mm against the test bacteria at 0.25 mg/ml. Further the antibacterial activity was confirmed by live and dead cell assay by fluorescence microscopy and morphological changes of bacteria were studied by Scanning electron microscope (SEM). The study recommends that the synthesized silver nanoparticles using Dillenia indica extract have potential application in inhibition of bacteria owing to their potent antibacterial activity. 相似文献
2.
Yarabally R Girish Kanchipura R Raghavendra Dasappa Nagaraja Kothanahally S Sharath Kumar Sheena Shashikanth 《中国化学》2015,33(2):181-184
An efficient, inexpensive and simple method for the reduction of various α,β‐unsaturated ketones to corresponding saturated ketones using tosyl hydrazide as a hydrogen donor in DMF using calcium oxide powder has been reported. A variety of enones underwent reduction without forming undesirable side products. High chemoselectivity, broad functional group tolerance and good yields are the noteworthy features of this protocol. 相似文献
3.
Synthesis of Novel Benzofuran‐Gathered C‐2,4,6‐substituted Pyrimidine Derivatives Conjugated by Sulfonyl Chlorides: Orally Bioavailable,Selective, Effective Antioxidants and Antimicrobials Drug Candidates 下载免费PDF全文
Javarappa Rangaswamy Honnaiah Vijay Kumar Salakatte Thammaiah Harini Nagaraja Naik 《Journal of heterocyclic chemistry》2015,52(5):1349-1360
In the present study, we have made an effort to develop the novel synthetic antioxidants and antimicrobials with improved potency. The novel benzofuran‐gathered C‐2,4,6‐substituted pyrimidine derivatives 5a , 5b , 5c , 5d , 5e , 5f , 6a , 6b , 6c , 6d , 6e , 6f , 7a , 7b , 7c , 7d , 7e , 7f , 8a , 8b , 8c , 8d , 8e , 8f , 9a , 9b , 9c , 9d , 9e , 9f were synthesized by simple and efficient four‐step reaction pathway. Initially, o‐alkyl derivative of salicylaldehyde readily furnish corresponding 2‐acetyl benzofuran 2 in good yield, upon the treatment with potassium tertiary butoxide in the presence of molecular sieves. Further, Claisen–Schmidt condensation with aromatic aldehydes via treatment with thiourea followed by coupling reaction with different sulfonyl chlorides afforded target compounds. The structures of newly synthesized compounds were confirmed by IR, 1H NMR, 13C NMR, mass, and elemental analysis and further screened for their antioxidant and antimicrobial activities. The results showed that the synthesized compounds 8b , 8e , 9b , and 9e produced significant antioxidant activity with 50% inhibitory concentration higher than that of reference, whereas compounds 7d and 7c produced dominant antimicrobial activity at concentrations 1.0 and 0.5 mg/mL compared with standard Gentamicin and Nystatin, respectively. 相似文献
4.
Snehasish Panigrahy Jinhu Liang Shashank S. Nagaraja Zhaohong Zuo Gihun Kim Shijun Dong Goutham Kukkadapu William J. Pitz Subith S. Vasu Henry J. Curran 《Proceedings of the Combustion Institute》2021,38(1):479-488
To improve our understanding of the combustion characteristics of propyne, new experimental data for ignition delay times (IDTs), pyrolysis speciation profiles and flame speed measurements are presented in this study. IDTs for propyne ignition were obtained at equivalence ratios of 0.5, 1.0, and 2.0 in ‘air’ at pressures of 10 and 30 bar, over a wide range of temperatures (690–1460 K) using a rapid compression machine and a high-pressure shock tube. Moreover, experiments were performed in a single-pulse shock tube to study propyne pyrolysis at 2 bar pressure and in the temperature range 1000–1600 K. In addition, laminar flame speeds of propyne were studied at an unburned gas temperature of 373 K and at 1 and 2 bar for a range of equivalence ratios. A detailed chemical kinetic model is provided to describe the pyrolytic and combustion characteristics of propyne across this wide-ranging set of experimental data. This new mechanism shows significant improvements in the predictions for the IDTs, fuel pyrolysis and flame speeds for propyne compared to AramcoMech3.0. The improvement in fuel reactivity predictions in the new mechanism is due to the inclusion of the propyne + H?2 reaction system along with ?H radical addition to the triple bonds of propyne and subsequent reactions. 相似文献
5.
Syed Mohammed Basheeruddin Asdaq Earla Swathi Sunil S Dhamanigi Mohammed Asad Yahya Ali Mohzari Ahmed A. Alrashed Abdulrahman S. Alotaibi Batool Mohammed Alhassan Sreeharsha Nagaraja 《Molecules (Basel, Switzerland)》2020,25(22)
The carrot plant (Daucus carota) and its components are traditionally reported for the management of gastric ulcers. This study was performed to evaluate the role of carrot when administered concurrently with a conventional antiulcer treatment, pantoprazole, in alleviating gastric and duodenal ulcers in female experimental animals. The study involved standard animal models to determine the ulcer preventive effect using pylorus ligation, ethanol, and stress induced acute gastric ulcer models and duodenal ulcer models involving cysteamine. Acetic acid-induced chronic gastric ulcer and indomethacin-induced gastric ulcer models were used to evaluate the ulcer healing effect. Carrot fruit (500 mg/kg) and its co-administration with pantoprazole produced significant protection in an ethanol- and stress-induced acute gastric ulcer and cysteamine-induced duodenal ulcer. The healing of the acetic acid-induced chronic gastric ulcer was also augmented with this combination. Both total proteins and mucin contents were significantly increased in indomethacin-induced gastric ulcers. Similarly, in pylorus ligation, the pepsin content of gastric juice, total acidity, and free acidity were reduced. Overall, both ulcer preventive effects and ulcer healing properties of the pantoprazole were significantly enhanced in animals who received the co-administration of carrot fruit (500 mg/kg). 相似文献
6.
Suppose we have a renewal process observed over a fixed length of time starting from a random time point and only the times
of renewals that occur within the observation window are recorded. Assuming a parametric model for the renewal time distribution
with parameter θ, we obtain the likelihood of the observed data and describe the exact and asymptotic behavior of the Fisher information (FI)
on θ contained in this window censored renewal process. We illustrate our results with exponential, gamma, and Weibull models
for the renewal distribution. We use the FI matrix to determine optimal window length for designing experiments with recurring
events when the total time of observation is fixed. Our results are useful in estimating the standard errors of the maximum
likelihood estimators and in determining the sample size and duration of clinical trials that involve recurring events associated
with diseases such as lupus. 相似文献
7.
M. P. Telenkov Yu. A. Mityagin V. V. Agafonov K. K. Nagaraja 《Bulletin of the Lebedev Physics Institute》2015,42(12):343-345
Kinetics of intrasubband energy relaxation of electrons in the system of Landau levels lying below the optical phonon energy is studied. Extraordinary behavior of the relaxation of electronic subsystem excitation energy is detected. Despite the fact that its main channel is optical phonon emission, the total relaxation time exceeds the characteristic times of scattering on optical phonons by several orders of magnitude. 相似文献
8.
Kalkote Uttam Ramrao Choudhary Anil Ramkumar Natu Arvind Anant Ayyangar Nagaraja Ramanuja 《合成通讯》2013,43(10-11):1129-1135
1-Alkylaminoanthraquinones ( 2 a-f) and 1,4-bisalkylaminoanthraquinones ( 4 a-c) were prepared from aminoanthraquinones ( 1,3 ) by alkylation with alkyl sulphate/alkyl halide in presence of powdered sodium hydroxide, potassium carbonate and phase transfer catalyst. 相似文献
9.
Gundibasappa K. Nagaraja Vijayavittala P. Vaidya Koodamara Sheshappa Rai Kittappa M. Mahadevan 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2797-2806
A novel and efficient method for the synthesis of substituted thiazepines and diazepines has been developed. A simple one-pot reaction of chalcones 1a–f with 1-amino-2-mercapto-5-phenyl-1,3,4-triazole and o-phenylenediamine in the presence of a catalytic amount of sodium acetate under microwave irradiation gave 2-(3,8-diphenyl-7,8-dihydro[1,2,4]triazolo[3,4-b][1,3,4]thiadiazepin-6-yl)phenoles 2a–f and 2-(2-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-4-yl)phenoles 3a–f, respectively. The structure of all the synthesized compounds was elucidated on the basis of elemental analysis, IR, 1H and 13C NMR, and mass spectral data. 相似文献
10.
B. N. Lakshminarayana C. R. Gnanendra T. N. Mahadeva Prasad M. A. Sridhar Nagaraja Naik D. Chenne Gowda J. Shashidhara Prasad 《Journal of chemical crystallography》2010,40(8):686-690