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排序方式: 共有134条查询结果,搜索用时 15 毫秒
1.
A simple spectrophotometric method for determination of isoxsuprine hydrochloride in pharmaceuticals
A spectrophotometric method has been developed for the determination of isoxsuprine hydrochloride and its dosage forms, based on its coupling reaction with diazotized sulphanilic acid. The yellow chromophore has an absorption maximum at 440 nm. Beer's law holds over the range 0.8-8 mu/ml in the final solution. 相似文献
2.
[reaction: see text] Direct asymmetric catalytic Michael reactions have been performed using chiral-amine/acid bifunctional catalysts. Performed with 0.3 equiv of (S)-(+)-1-(2-pyrrolidinylmethyl)pyrrolidine and 0.3 equiv of trifluoroacetic acid as the catalyst, the reaction of alpha,alpha-dialkylaldehydes with (E)-beta-nitrostyrene provided the alpha,alpha-dialkyl Michael products in up to 96% yield with up to 91% ee. With respect to enantioselectivity, l-proline was a poor catalyst of this class of Michael reactions. 相似文献
3.
Glass-ceramic was prepared by sol–gel method using Ca(NO3)2·4H2O and P2O5 as Ca and P precursors, respectively. In order to improve the bioactivity of the implant material, glass-ceramic (β-Ca2P2O7) coating was developed on 316L SS substrate by spin coating method. Coating was annealed at different temperatures and its
corrosion resistance was evaluated by electrochemical polarization and impedance analysis using Ringer’s solution as electrolyte.
The results from the present study, show excellent corrosion resistance for coated 316L SS, corroborated by the high values
of charge transfer resistance from impedance analysis and higher breakdown and repassivation potential with the corresponding
lower current density from polarization measurements. Based on the results, the glass-ceramic coating on 316L SS can be considered
as a corrosion resistant material. 相似文献
4.
Rajakumar Govindasamy Vaishnavi Raja Sonalika Singh Mydhili Govindarasu Sulthana Sabura Kaliaperumal Rekha V. Devi Rajeswari Salman S. Alharthi Manju Vaiyapuri Rajagopal Sudarmani S. Jesurani Baskar Venkidasamy Muthu Thiruvengadam 《Molecules (Basel, Switzerland)》2022,27(17)
The advanced technology for synthesizing nanoparticles utilizes natural resources in an environmentally friendly manner. Additionally, green synthesis is preferred to chemical and physical synthesis because it takes less time and effort. The green synthesis of cobalt oxide nanoparticles has recently risen due to its physico-chemical properties. In this study, many functional groups present in Psidium guajava leaf extracts are used to stabilize the synthesis of cobalt oxide nanoparticles. The biosynthesized cobalt oxide nanoparticles were investigated using UV-visible spectroscopic analysis. Additionally, Fourier-transform infrared spectroscopy revealed the presence of carboxylic acids, hydroxyl groups, aromatic amines, alcohols and phenolic groups. The X-ray diffraction analysis showed various peaks ranging from 32.35 to 67.35°, and the highest intensity showed at 36.69°. The particle size ranged from 26 to 40 nm and confirmed the average particle size is 30.9 nm. The green synthesized P. guajava cobalt oxide nanoparticles contain cobalt as the major abundant element, with 42.26 wt% and 18.75 at% confirmed by the EDAX techniques. SEM images of green synthesized P. guajava cobalt oxide nanoparticles showed agglomerated and non-uniform spherical particles. The anti-bacterial activity of green synthesized P. guajava cobalt oxide nanoparticles was evaluated against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli with a 7 to 18 mm inhibitory zone. The photocatalytic activity was evaluated using green synthesized P. guajava cobalt oxide nanoparticles and observed 79% of dye degradation. The MTT assay of P. guajava cobalt oxide nanoparticles showed an excellent cytotoxic effect against MCF 7 and HCT 116 cells compared to normal cells. The percentage of cell viability of P. guajava cobalt oxide nanoparticles was observed as 90, 83, 77, 68, 61, 58 and 52% for MCF-7 cells and 82, 70, 63, 51, 43, 40, and 37% for HCT 116 cells at the concentration of 1.53, 3.06, 6.12, 12.24, 24.48, 50, and 100 μg/mL compared to control cells. These results confirmed that green synthesized P. guajava cobalt oxide nanoparticles have a potential photocatalytic and anti-bacterial activity and also reduced cell viability against MCF-7 breast cancer and HCT 116 colorectal cancer cells. 相似文献
5.
Priyanka Lohar Manish Kumar Sharma Amit Kumar Sahu Rajeswari Rathod Pinaki Sengupta 《Biomedical chromatography : BMC》2019,33(12)
The combination of acebrophylline (ABP), levocetirizine (LCZ) and pranlukast (PRN) is used to treat allergic rhinitis, asthma, hay‐fever and other conditions where patients experience difficulty in breathing. This study was carried out with the aim of developing and validating a reverse‐phase high‐performance liquid chromatographic bioanalytical method to simultaneously quantitate ABP, LCZ and PRN in rat plasma. The objective also includes determination of the pharmacokinetic interaction of these three drugs after administration via the oral route after individual and combination treatment in rat. Optimum resolution between the analytes was observed with a C18 Kinetex column (250 mm × 4.6 mm × 5 μm). The chromatography was performed in a gradient elution mode with a 1 mL/min flow rate. The calibration curves were linear over the concentration range of 100–1600 ng/mL. The intra‐ and inter‐day precision and accuracy were found to be within acceptable limits as specified in US Food and Drug Administration guideline for bioanalytical method validation. The analytes were stable on the bench‐top (8 h), after three freeze–thaw cycles, in the autosampler (8 h) and as a dry extract (?80°C for 48 h). The statistical results of the pharmacokinetic study in Sprague–Dawley rats showed a significant change in pharmacokinetic parameters for PRN upon co‐administration of the three drugs. 相似文献
6.
Seth Sheeba Thavamani Murugesan Sudharsan Anitha Santhana Mariya Devarajan Suresh Arlin Jose Amali Sanniyasi Rajeswari Thomas Peter Amaladhas 《应用有机金属化学》2020,34(9):e5752
The catalytic activity of CeO2 and palladium nanoparticles supported fly ash zeolite (CeO2/Pd@FAZ) for Csp2-Csp2 bond formation was studied. CeO2/Pd@FAZ was characterized by FTIR, XRD, EDAX and TEM studies. In the Suzuki-Miyauracross-coupling reaction, biphenyl derivatives with excellent yields were obtained, and the reaction conditions were optimized. The catalytic activity was explored using a wide variety of diversely substituted aryl bromides and chlorides with aryl boronic acid under optimized reaction conditions. The recyclability of the catalyst was established for three cycles, with the conversion rate from 99 to 40%, which gained the advantage of heterogeneous catalysis. 相似文献
7.
8.
A. Sengupta B. Rajeswari R. M. Kadam R. J. Kshirsagar 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(2):903-908
The use of serpentine as a potential nuclear shielding material necessitates a chemical quality control of the samples before
its use in reactors. With this in view, characterization of these mineral samples was carried out using inductively coupled
plasma atomic emission spectrometry (ICP-AES) and Instrumental neutron activation analysis (INAA) methods. The analytical
results obtained by both ICP-AES and NAA techniques were found to be comparable. Na, Cr, Co, Zn, and Cu were found to be present
in all samples of Indian origin while Ga, Ag, Ni, and Cd were found to below the limits of detection. A comparison on the
detection limits of elements of interest was also carried out by both the analytical techniques and found to be in good agreement.
An infrared spectroscopic investigation was also carried out on all the mineral samples. Bands at 3,689 and 3,648 cm−1 were attributed to inner and outer hydroxyl stretching of Mg–OH, respectively. The weak and broad band centered around 3,416 cm−1 was assigned due to the stretching vibrations of the adsorbed water molecules while three bands at 1076, 1022 and 968 cm−1 were prescribed to the vibrations of the SiO4 tetrahedra. 相似文献
9.
N. Rajeswari R. Nagarathinam S. Viswanathan H. Kothandaraman E. Ponnusamy 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(12):1585-1610
New polymaleamides were synthesized by ring-opening polyaddition of N,N'-biphenylbismaleimide (BPBMI) to the aliphatic diamines 1,4-diaminobutane, 1,6-diaminohexane, 1,8-diaminooctane, piperazine, and 2,5-dimethylpiperazine in m-cresol. The appropriate model compound was also prepared. These polymers are completely soluble in concentrated sulfuric acid as well as in m-cresol and are found to be insoluble in common organic solvents. The identities of BPBMI, the model compound, and the polymaleamides were confirmed by elemental analysis and IR spectroscopy. These polymaleamides were found to have inherent viscosities in the range 0.10–0.14 dL/g. Their IR spectra reveal the retention of cis-geometry about the C=C bonds in BPBMI and in the polymaleamides. The thermal degradation behavior of the polymaleamides was studied by thermogravimetric analysis, differential scanning calorimetry, and mass spectrometry. Fragmentation schemes for the polymaleamides are proposed. 相似文献
10.
Harinash Rao Sulin Choo Sri Raja Rajeswari Mahalingam Diajeng Sekar Adisuri Priya Madhavan Abdah Md. Akim Pei Pei Chong 《Molecules (Basel, Switzerland)》2021,26(7)
Biofilms play an essential role in chronic and healthcare-associated infections and are more resistant to antimicrobials compared to their planktonic counterparts due to their (1) physiological state, (2) cell density, (3) quorum sensing abilities, (4) presence of extracellular matrix, (5) upregulation of drug efflux pumps, (6) point mutation and overexpression of resistance genes, and (7) presence of persister cells. The genes involved and their implications in antimicrobial resistance are well defined for bacterial biofilms but are understudied in fungal biofilms. Potential therapeutics for biofilm mitigation that have been reported include (1) antimicrobial photodynamic therapy, (2) antimicrobial lock therapy, (3) antimicrobial peptides, (4) electrical methods, and (5) antimicrobial coatings. These approaches exhibit promising characteristics for addressing the impending crisis of antimicrobial resistance (AMR). Recently, advances in the micro- and nanotechnology field have propelled the development of novel biomaterials and approaches to combat biofilms either independently, in combination or as antimicrobial delivery systems. In this review, we will summarize the general principles of clinically important microbial biofilm formation with a focus on fungal biofilms. We will delve into the details of some novel micro- and nanotechnology approaches that have been developed to combat biofilms and the possibility of utilizing them in a clinical setting. 相似文献