The Pr doped cubic nanoceria acts as better catalyst under both oxygen lean and oxygen rich environments, and their application to enhance combustion property of hydrocarbon fuel is explored.
Display ...omitted
A series of praseodymium (Pr) doped cubic ceria nanoparticles (CeO2 NPs) with different ratio of cerium (Ce) and ‘Pr’ was synthesized by hydrothermal method. Manganese (‘Mn’) doped cubic CeO2 NPs with 10:90 ratio of Mn:Ce and undoped cubic CeO2 NPs have also been synthesized. The crystalline structure of the synthesized nanomaterials has been studied by powder X-Ray diffraction (XRD) and Rietveld analysis. In the Raman spectrum, the intensity of F2g signal at 450–460 cm−1 decreased while the intensity of extrinsic vacancy at 570–580 cm−1 increased by doping with ‘Pr’ or ‘Mn’ in cubic CeO2 nanocrystals. X-ray photoelectron spectroscopy (XPS) results showed that surface oxygen vacancy of cubic CeO2 NPs increased by doping with 25 % of ‘Pr’. The ‘Pr’ doped CeO2 NPs (Pr:Ce = 25:75) exhibited higher surface adsorption dynamic oxygen storage capacity (OSCDyn), while the ‘Mn’ doped cubic CeO2 NPs (Mn:Ce = 10:90) showed increased bulk lattice OSCDyn. The ‘Pr’ doped cubic CeO2 NPs (Pr:Ce = 25:75) exhibited better low temperature catalytic combustion activity, and their nanodispersion in mineral turpentine oil (MTO) added liquefied petroleum gas (LPG) exhibited better fuel efficiency with a flame temperature of 912 °C.
Background: Surface functionalization of gold nanoparticles (AuNPs) has emerged as a promising field of research with enormous biomedical applications. The folate (FA)-attached polymer-gold ...nanoconjugates play vital role in targeting the cancer cells. Methods: AuNPs were synthesized by using di- or tri-carboxylate-polyethylene glycol (PEG) polymers, including citrate-PEG (CPEG), malate-PEG (MAP), and tartrate-PEG (TAP), as a reducing and stabilizing agent. After synthesis of polymer-AuNPs, the freely available hydroxyl and carboxylate groups of CPEG, MAP, and TAP were used to attach a cancer cell- targeting agent, FA, via a 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxy succinimide coupling reaction to obtain FA-CPEG-AuNP, FA-MAP-AuNP, and FA-TAP-AuNP nanoconjugates, respectively. The 5-fluorouracil (5FU) was attached to pi back-bonded carbonyl oxygens of the nanoconjugates, and the in vitro drug release profile was studied by high pressure liquid chromatography. Biocompatibility profiles of the FA-CPEG-AuNP, FA-MAP-AuNP, and FATAP-AuNP nanoconjugates were investigated using adult human dermal fibroblasts. Anti- breast cancer activity of 5FU-loaded nanoconjugates was investigated using MCF-7 breast cancer cells. Results: X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy analyses confirmed that AuNPs attached to CPEG, MAP, or TAP via the formation of pi back bonding between AuNPs and the ester carbonyl group. The pi back-bonded nanoconjugates exhibited sustained release of 5FU up to 27 days. FA-MAP-AuNPs exhibited an IC.sub.50 at 5 microlg/mL, while FACPEG-AuNPs and FA-TAP-AuNPs showed the IC.sub.50 at 100 microg/mL toward MCF-7 cancer cells. Conclusion: The developed polymer pi back-bonded multifunctional gold nanoconjugates could be used as a potential drug delivery system for targeting MCF-7 cancer cells. Keywords: polymer-gold nanoconjugates, 5-fluorouracil, anticancer activity, MCF- 7 cells, green synthesis
Display omitted
► Low molecular weight PLGA–PEG–PLGA triblock copolymers are obtained in solid form. ► First time, Isoniazid loaded polymeric core–shell nanoparticles are reported. ► In vitro release ...kinetics mechanisms are investigated. ► The in vitro and in vivo drug release characteristics are reported. ► The nanoparticles showed a sustained and mechanistic drug release up to 124h.
A series of biodegradable low molecular weight PLGA–PEG–PLGA tri-block copolymers have been synthesized in powder form. The anti-tuberculosis drug Isoniazid (INH) loaded polymeric core–shell nanoparticles (CSNPs) have been prepared by sonication followed by water-in-oil-in-water (w/o/w) double emulsification technique. The nanoparticles (NPs) have been characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD) and X-ray photo electron spectroscopic (XPS) techniques. The drug loaded CSNPs were found to be 150–400nm in size with spherical shape. The drug loading efficiency and drug content of the polymer NPs were determined by UV–vis spectrophotometry. The drug loading efficiency and drug content of the NPs were (12.8–18.67%) and (6.4–8.9%) respectively. The in vitro release behavior of the polymer NPs has been investigated by UV–vis spectrophotometry and the release kinetics mechanism has been evaluated by Korsemeyer-Peppas (KP) and Higuchi models. The in vitro release studies show initial burst release followed by controlled and uniform release for longer duration. The pharmacokinetic studies show that the INH bioavailability of INH loaded CSNPs is 28 fold higher than that of free INH and also the CSNPs show sustained drug release for longer duration.
Four new heteroleptic silver(I) complexes with the general formula Ag(L
)(nap) (
-
), where L
= 2-(1-(4-substitutedphenyl)ethylidene)hydrazinecarbothioamide and nap = naproxen, have been ...synthesized and characterized. The geometric parameters determined from density functional theory and UV-Vis studies indicate distorted tetrahedral geometry around silver(I) ion. Fourier transform infrared (FT IR) spectra evidenced asymmetric bidentate coordination mode of carboxyl oxygen atoms of naproxen with silver(I) ion. The complexes are stable for 72 h and biocompatibility was analysed towards normal human dermal fibroblast cells, which showed non-toxic nature up to 100 ng/ml.
anti-proliferative activity of the complexes by MTT assay was tested against three human cancerous cell lines and one non-tumorigenic human breast epithelial cell line (MCF-10a) in which the complex
exhibited enhanced activity. The morphological changes observed by acridine orange/ethidium bromide and Hoechst 33258 staining method reveal apoptosis-inducing ability of the complexes. The molecular docking studies suggest hydrogen bonding, hydrophobic and π-pair interactions with the active site of epidermal growth factor receptor, vascular endothelial growth factor receptor 2 and lipoxygenase receptors.
The effect of π-back-bonding between AuNPs and the carbonyl group of multiblock copolyester on tuberculosis multi-drug delivery has been investigated. The carbonyl group of copolyester has vacant p ...orbitals and these vacant orbitals accept electron clouds from the filled d orbitals of Au0 to form π-back-bonding, which enhances the electron density for the carbonyl oxygen. This high electron density results in the strong binding of drug molecules with multiblock copolyesters and hence sustained drug release is achieved for a longer duration when compared to polymer systems without AuNPs. A new series of tartarate-linked poly(lactic-co-glycolic acid) (PLGA)-polyethylene glycol (PEG)-based multiblock copolymers has been synthesized using a solvent-free melt reaction. The biocompatibility of multiblock copolyesters and AuNP nanoconjugates was investigated with an in vitro cytotoxicity study on the Vero cell line. Three major tuberculosis drugs, namely, rifampicin-, isoniazid- and pyrazinamide-loaded AuNP multiblock copolymer NPs were prepared by probe sonication followed by the self-assembly method. An in vitro drug release experiment was carried out and the amount of the three drugs released at various time intervals was determined simultaneously by the HPLC technique. The nanoconjugates exhibit 33%-40% RIF, 71%-95% INH, 77%-99% PYZ loading efficiencies, while the polymer NPs exhibit relatively lesser values. The nanoconjugates show sustained drug release for up to 264 h.
The effect of pi-back-bonding between AuNPs and the carbonyl group of multiblock copolyester on tuberculosis multi-drug delivery has been investigated. The carbonyl group of copolyester has vacant p ...orbitals and these vacant orbitals accept electron clouds from the filled d orbitals of Au super(0) to form pi-back-bonding, which enhances the electron density for the carbonyl oxygen. This high electron density results in the strong binding of drug molecules with multiblock copolyesters and hence sustained drug release is achieved for a longer duration when compared to polymer systems without AuNPs. A new series of tartarate-linked poly(lactic-co-glycolic acid) (PLGA)-polyethylene glycol (PEG)-based multiblock copolymers has been synthesized using a solvent-free melt reaction. The biocompatibility of multiblock copolyesters and AuNP nanoconjugates was investigated with an in vitro cytotoxicity study on the Vero cell line. Three major tuberculosis drugs, namely, rifampicin-, isoniazid- and pyrazinamide-loaded AuNP multiblock copolymer NPs were prepared by probe sonication followed by the self-assembly method. An in vitro drug release experiment was carried out and the amount of the three drugs released at various time intervals was determined simultaneously by the HPLC technique. The nanoconjugates exhibit 33%-40% RIF, 71%-95% INH, 77%-99% PYZ loading efficiencies, while the polymer NPs exhibit relatively lesser values. The nanoconjugates show sustained drug release for up to 264 h.
A meta-analysis was carried out using 20 publicly available metagenomic datasets obtained from diverse wastewater samples. A taxonomic assignment was performed, and the diversity measures were ...calculated. A total of 6,11,942 reads were analysed, and the sequences were assigned to 2605 operational taxonomic units (OTUs) based on ≥ 97% sequence identity. The taxonomic classification carried out at the phyla level indicated that
Proteobacteria
,
Firmicutes
, and
Bacteroidetes
were the dominant bacterial phyla. At the genera level,
Comamonas
,
Pseudomonas
,
Acidovorax
,
Arcobacter
, and
Acinetobacter
were prevalent across most wastewaters, forming the core microbial genera. Similarly,
Burkholderiaceae
,
Rhodocyclaceae
,
Ruminococcaceae
,
Rhodobacteraceae
, and
Rhizobiaceae
formed the core microbial families across the selected wastewaters. Spearman correlation analysis showed positive and negative correlations between the identified core microbiome, indicating the symbiotic relationship among bacteria involved in bioremediation. Metabolic pathway analysis indicated the presence of genes related to xenobiotics biodegradation and metabolism pathways in the datasets analysed. Majority of the wastewaters harbored an unclassified and uncultured bacterial consortia, indicating a novel microbiome yet to be characterised. Diversity analysis showed similarity in the habitation of microbiome irrespective of the physico-chemical nature and characteristics of wastewaters. As a comprehensive survey of diverse wastewater microbiome, this study provides insights into the core microbial diversity that could improve the existing bioremediation strategies.
Misleading identification and subsequent publications on biological, molecular, and aquaculture data of mangrove mud crab (genus
Scylla
de Hann 1833) is a major concern in many countries. In this ...study, multiple molecular markers were used for genetic identification of all four known mud crab species under genus
Scylla
collected from India, Philippines, Myanmar, Malaysia and Indonesia. Internal Transcribed Spacer (
ITS
-
1
), Polymerase chain reaction (PCR)–Restriction Fragment Length Polymorphism (PCR–RFLP) and PCR-based species-specific markers were used to resolve taxonomic ambiguity. PCR–RFLP techniques using
NlaIV
and
BsaJI
restriction endonucleases were efficient to differentiate four different mud crab species under genus
Scylla
with specific fragment profile. The results also justified the use of
ITS
-
1
and PCR-based species-specific markers to identify mud crab species available in many countries quite rapidly and effectively. Several new molecular markers generated during the study are reported here to resolve the taxonomic ambiguity of
Scylla
species and the results reconfirmed that India is only having two commonly available mud crab species which was reported by the authors earlier.
Tuberculosis Research Centre, Chennai.
To rapidly identify multidrug-resistant Mycobacterium tuberculosis using a novel method.
A new assay, based on DNA-lanthanide fluorescence, was standardised and ...evaluated using 93 each of coded rifampicin-resistant and rifampicin-sensitive M. tuberculosis clinical isolates for the correct identification of rifampicin resistance. The results obtained by the new assay were compared with the conventional results.
The new assay gave a sensitivity and specificity of 88% and 85%, respectively. It is simple, easy to perform and requires 48 hours for the drug susceptibility results to be available after obtaining the primary culture.
PDF
