Central University of Kerala

About: Central University of Kerala is a education organization based out in Kāsaragod, India. It is known for research contribution in the topics: Population & Catalysis. The organization has 556 authors who have published 881 publications receiving 7474 citations.

Prevalence of mutations in genes associated with isoniazid resistance in Mycobacterium tuberculosis isolates from re-treated smear-positive pulmonary tuberculosis patients: A meta-analysis.

Abstract: Objectives The prevalence of isoniazid (INH) monoresistance is high in India. In this study, molecular epidemiological characteristics associated with INH resistance mutations in Mycobacterium tuberculosis in codon katG315 and in the promoter region of the inhA gene were investigated. Methods Sputum specimens of smear-positive tuberculosis (TB) patients were subjected to GenoType MTBDRplus assay to identify katG and inhA mutations in M. tuberculosis. In addition to the current study, 17 publications assessed 14 100 genotypically resistant M. tuberculosis isolates for mutations in katG inclusive of codon 315. Results In total, 1821 (11.8%) of 15 438 INH-resistant strains had detectable mutations: 71.0% in katG315 and 29.0% in the inhA promoter region. The prevalence of IHN monoresistance was 89.1% in the economically-active age group, 0.4% in the paediatric age group and 10.5% in those aged >60 years; the rate in males and females was 12.0% and 10.8%, respectively. Meta-analysis derived a pooled katGS315T resistant TB prevalence of 67.3% (95% CI 59.3–75.4%) with Q = 732.19, I2 = 98.35% and P = 0.000 for treated TB cases. Conclusion INH resistance was spread widely and transmission of INH-resistant isolates, especially with katG315T mutation, was confirmed. Therefore, it is important to diagnose katG315T mutants among INH-resistant strains as it may be a risk factor for subsequent development of multidrug-resistant TB (MDR-TB). Prompt detection of patients with INH-resistant strains would expedite modification of treatment regimens, and appropriate infection control measures could be taken in time to diminish the risk of further development and transmission of MDR-TB.

Synthesis, Pharmacological and Toxicological Screening of Penicillin-Triazole Conjugates (PNTCs).

Abstract: Open in a separate window A series of hybrid antimicrobial compounds were prepared by carboxylic acid protection of 6-aminopenicillanic acid using benzyl alcohol and thionyl chloride succeeded by azide displacement using trifluoromethanesulfonyl azide in dichloromethane. The azide thus formed was reacted with substituted alkynes to furnish benzyl-protected penicillin–triazole conjugates. Benzyl deprotection of the conjugates resulted in furnishing PNTCs under water methanol mixture using Pd/C as a catalyst. The PNTCs (7a–j) formed were screened for in vitro antibacterial potency against pathogenic strains of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pyogenes and antifungal potency against Candida albicans, Aspergillus niger, and Aspergillus clavatus. Further antimicrobial evaluation revealed compounds 7c, 7d, 7e, 7g, and 7i to be the most compounds of the series with minimum inhibitory concentration value for antibacterial in the range 0.5–50 μg/mL and for antifungal in the range 9–300 μg/mL. Toxicological analysis documented for compounds 7c, 7d, 7e, 7g, and 7i revealed compound 7i to be the most promising member of the series with 1000 and 500 mg/kg LD50, and no-observed-adverse-effect level to facilitate future clinical studies of the same.

High voltage generation from lead-free magnetoelectric coaxial nanotube arrays and their applications in nano energy harvesters

Abstract: Harvesting energy from surrounding vibrations and developing self-powered portable devices for wireless and mobile electronics have recently become popular. Here the authors demonstrate the synthesis of piezoelectric energy harvesters based on nanotube arrays by a wet chemical route, which requires no sophisticated instruments. The energy harvester gives an output voltage of 400 mV. Harvesting energy from a sinusoidal magnetic field is another interesting phenomenon for which the authors fabricated a magnetoelectric energy harvester based on piezoelectric–magnetostrictive coaxial nanotube arrays. Piezoelectric K0.5Na0.5NbO3 (KNN) is fabricated as the shell and magnetostrictive CoFe2O4 (CFO) as the core of the composite coaxial nanotubes. The delivered voltages are as high as 300 mV at 500 Hz and at a weak ac magnetic field of 100 Oe. Further tailoring of the thickness of the piezoelectric and magnetic layers can enhance the output voltage by several orders. Easy, single-step wet chemical synthesis enhances the industrial upscaling potential of these nanotubes as energy harvesters. In view of the excellent properties reported here, the lead-free piezoelectric component (KNN) in this nanocomposite should be explored for eco-friendly piezoelectric as well as magnetoelectric power generators in nanoelectromechanical systems (NEMS).

Functionalization of Magnetic Hollow Spheres With (3-Aminopropyl)Triethoxysilane for Controlled Drug Release

Abstract: Direct functionalization strategy has been employed to modify the surface of the magnetic hollow spheres (MHS) with (3-aminopropyl)triethoxysilane (APTES) for controlled drug release. The MHS were prepared by the solvothermal method and characterized by X-ray diffraction, field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy, and vibrating sample magnetometer. The FE-SEM study shows that MHS have a size of ~200 nm and are made up of smaller nanoparticles (NPs) having average size of ~20–25 nm. MHS exhibits a superparamagnetic behavior with a saturation magnetization of 74 emu/g at room temperature. The direct functionalization of MHS with APTES provided an efficient loading of model anti-cancer drug Camptothecin (CPT). The drug release study performed at pH of 7.4 showed 30% of CPT release in a controlled way after 4 h.