National Chemical Laboratory

About: National Chemical Laboratory is a facility organization based out in Pune, Maharashtra, India. It is known for research contribution in the topics: Catalysis & Nanoparticle. The organization has 8891 authors who have published 14837 publications receiving 387600 citations.

Decreased antioxidant enzymes and membrane essential polyunsaturated fatty acids in schizophrenic and bipolar mood disorder patients.

Abstract: Oxidative stress-mediated cell damage has been considered in the pathophysiology of schizophrenia. Abnormal findings have often been considered related to differences in ethnicity, life style, dietary patterns and medications, all of which influence indices of oxidative stress and oxidative cell damage. To minimize these confounds, schizophrenic patients were compared with age-matched control subjects with the same ethnic background and similar lifestyle, as well as with bipolar mood disorder (BMD) patients. Levels of antioxidant defense enzymes (i.e. superoxide dismutase, SOD; catalase, CAT; and glutathione peroxidase, GPx) were lower in schizophrenic patients than in controls, indicating conditions for increased oxidative stress. The contents of plasma thiobarbituric acid reactive substances (TBARS) were only marginally higher in schizophrenic patients, who had normal levels of arachidonic acid (AA), a major source of TBARS, indicating no significant oxidative membrane lipid peroxidation. Levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), however, were significantly lower in schizophrenic patients. When the same indices in BMD patients were compared with findings in matched controls, levels of only SOD and CAT were lower in the patients, whereas GPx was not. Again, as in schizophrenia, the contents of TBARS were marginally higher in BMD patients with no change in levels of AA. Levels of alpha-linolenic acid and EPA were significantly lower and levels of DHA were slightly lower in BMD patients. These data indicate that certain biochemical characteristics may be common to a spectrum of psychiatric disorders, and suggest supplementation of antioxidants and essential fatty acids might affect clinical outcome.

Motor subtype and cognitive decline in Parkinson’s disease, Parkinson’s disease with dementia, and dementia with Lewy bodies

Abstract: Background: A previous cross sectional study found over-representation of a postural instability gait difficulty (PIGD) motor subtype in Parkinson’s disease patients with dementia (PDD) and dementia with Lewy bodies (DLB), compared with Parkinson’s disease (PD). Aims: (1) To examine rates of cognitive and motor decline over two years in PD (n = 40), PDD (n = 42) and DLB (n = 41) subjects, compared with age matched controls (n = 41), (2) to record whether motor phenotypes of PD, PDD, and DLB subjects changed during the study, (3) to find out if cognitive and motor decline in PD was associated with baseline motor subtype, and (4) to report the incidence of dementia in PD patients in relation to baseline motor subtype. Results: Most of PDD and DLB participants were PIGD subtype at baseline assessment. In the non-demented PD group, tremor dominant (TD) and PIGD subtypes were more evenly represented. Cognitive decline over two years was greater in PDD and DLB groups (mean decline in MMSE − 4.5 and − 3.9, respectively), compared with PD ( − 0.2) and controls (−0.3). There was an association between PIGD subtype and increased rate of cognitive decline within the PD group. Of 40 PD patients, 25% of the 16 PIGD subtype developed dementia over two years, compared with none of the 18 TD or six indeterminate phenotype cases (χ 2 = 6.7, Fisher’s exact test p Conclusion: A PIGD motor subtype is associated with a faster rate of cognitive decline in PD and may be considered a risk factor for incident dementia in PD.

Biosynthesis of zirconia nanoparticles using the fungus Fusarium oxysporum

Abstract: Zirconia nanoparticles may be produced by challenging the fungus Fusarium oxysporum with aqueous ZrF62− anions; extra-cellular protein-mediated hydrolysis of the anionic complexes results in the facile room temperature synthesis of nanocrystalline zirconia. Extracellular hydrolysis of the metal anions by cationic proteins of molecular weight around 24 to 28 kDa, which are rather similar in nature to silicatein, is shown to be responsible for the synthesis of zirconia nanoparticles, opening up the exciting possibility of large-scale biological synthesis of technologically important oxide materials.

Antibiotic mediated synthesis of gold nanoparticles with potent antimicrobial activity and their application in antimicrobial coatings

Abstract: We report a one-pot synthesis of spherical gold nanoparticles (52–22 nm) and their capping with cefaclor, a second-generation antibiotic, without use of other chemicals. The differently sized gold nanoparticles were fabricated by controlling the rate of reduction of gold ions in aqueous solution by varying the reaction temperature (20–70 °C). The primary amine group of cefaclor acted as both the reducing and capping agent for the synthesis of gold nanoparticles leaving the β-lactam ring of cefaclor available for activity against microbes. Antimicrobial testing showed that cefaclor reduced gold nanoparticles have potent antimicrobial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria as compared to cefaclor or gold nanoparticles alone. The minimum inhibition concentrations (MICs) of cefaclor reduced gold nanoparticles were 10 µg mL−1 and 100 µg mL−1 for S. aureus and E. coli respectively. The cefaclor reduced gold nanoparticles were further coated onto poly(ethyleneimine) (PEI) modified glass surfaces to obtain antimicrobial coatings suitable for biomedical applications and were tested against E. coli as an exemplar of activity. The antimicrobial coatings were very robust under adverse conditions (pH 3 and 10), inhibited the growth of E. coli on their surfaces, and could be used many times with retained activity. Results from a combined spectroscopic (FTIR) and microscopic study (AFM) suggest that the action of these novel particles is through the combined action of cefaclor inhibiting the synthesis of the peptidoglycan layer and gold nanoparticles generating “holes” in bacterial cell walls thereby increasing the permeability of the cell wall, resulting in the leakage of cell contents and eventually cell death.

Role of halide ions and temperature on the morphology of biologically synthesized gold nanotriangles.

Abstract: In this paper, we demonstrate the effect of halide ions on the formation of biogenically prepared gold nanotriangles using the leaf extract of lemongrass (Cymbopogon flexuosus) plant. We have also studied the effect of halide ions on the morphology of biogenic nanotriangles. It has been shown that iodide ions have a greater propensity to transform flat gold nanotriangles into circular disk-like structures as compared to other halide ions. The study also suggests that the presence of Cl- ions during the synthesis promotes the growth of nanotriangles, whereas the presence of I- ions distorts the nanotriangle morphology and induces the formation of aggregated spherical nanoparticles. The change in the morphology of gold nanotriangles has been explained in terms of the ability of the halide ions to stabilize or inhibit the formation of (111) faces to form [111] oriented gold nanotriangles. Last, we have also shown that the temperature is an important parameter for controlling the aspect ratio and the relative amounts of gold nanotriangles and spherical particles. The results show that, by varying the temperature of reaction condition, the shape, size, and optical properties of anisotropic nanoparticles can be fine-tuned.