Effect of Various Nutritional Supplements on Hyaluronic Acid Production

Effect of various nutritional supplementations on production of hyaluronic acid (HA) using Streptococcus equi subsp. zooepidemicus ATCC 39920 was evaluated at shake flask. Among the different carbon sources used, maltodextin showed HA of 0.9 g/L followed by 0.7 g/L for dextrose. L-arginine HCl at 2.0 g/L increased the yield of HA from 0.7 g/L to 0.85 g/L. L-arginine and L-glutamine showed the yield of HA of 0.7 g/L and 1.0 g/L, respectively at 2.0 g/L concentration. L-glutamine (2.0 g/L) and uridine (0.75 g/L) showed HA yield of 0.8 and 1.045 g/L, respectively. Addition of sodium glucuronate at 0.25 g/L concentration at 8 h, the yield of HA was increased from 0.7 g/L to 0.85 g/L. Pantothenic acid at concentration of 8.33 mg/L supplemented to the P10 medium, yield of 0.87 g/L of HA was obtained. Active dry yeast at 5.0 g/L increased yield of HA from 0.7 g/L to 0.85 g/L. Tween 80 at higher concentration reduced HA production. The addition of MgSO4.7H2O at 1.0 g/L improved the production of HA. Other metal ions like manganese, ferrous, copper, and zinc have no significant effect on HA production. Thus, it has been found that various nutritional supplements have effect on production of HA using S. equi subsp. zooepidemicus ATCC 39920

Effect of Various Physical Parameters and Statistical Medium Optimization on Production of Hyaluronic Acid Using S. Equi Subsp. Zooepidemicus ATCC 39920

It has been shown that initial conditions for bacterial cultivation are extremely important for the successful production of hyaluronic acid (HA) by fermentation. We investigated several physical parameters that affect productivity of HA under shake flask. i.e. transfer criteria of seed, agitation and aeration of fermentation flasks. Among the various physical parameters studied, inoculum age of 8-10 h, pH 6.4, optical density (600 nm) 2.0 and 3% level inoculum transfer found to be optimum. After inoculating with Streptococcus equi subsp. zooepidemicus ATCC 39920, the temperature 37 0C and 90 rpm found optimum during growth as well as for the HA production. The fractional factorial design of six factors with two levels showed yeast extract, potassium dihydrogen phosphate and sodium bicarbonate as significant model terms. The factor potassium dihydrogen phosphate was relatively more significant than yeast extract.

CdSe Quantum Dots Anchored on TiO2and Carbon Nanotubes: 1D Architectures as Scaffolds to Improve the Efficiency of Solar Cells

Environmentally friendly energy resources are needed to meet our clean energy demand. Semiconductor nanoparticle and nanotube assemblies provide new ways to develop next generation solar cells.[1-4]. Of particular interest is the nanowire/nanotube architecture which can significantly improve the efficiency of nanostructure based solar cells. We have now developed quantum dot solar cells by assembling different size CdSe quantum dots on TiO2 films composed of particle and nanotube morphologies (Scheme 1). Upon bandgap excitation, CdSe quantum dots inject electrons into TiO2 nanoparticles and nanotubes, thus enabling the generation of photocurrent in a photoelectrochemical solar cell. These composite semiconductor nanostructures can be tailored to tune the photoelectrochemical response via size control of CdSe quantum dots and improve the photoconversion efficiency by facilitating the charge transport through TiO2 nanotube architecture. Ways to improve power conversion efficiency and maximize the light harvesting capability through the construction of a rainbow solar cell and carbon nanotube-semiconductor hybrid assemblies will be presented. The salient features of carbon nanotube and graphene scaffolds for facilitating charge collection and charge transport will also be discussed

Experimental Techniques for the Measurement of Mechanical Properties of Materials Used in Microelectromechanical Systems

The knowledge of mechanical properties of materials used in microelectromechanical systems (MEMS) devices is critical not only in designing structures such as cantilevers and beams but also for ensuring their reliability during operation of these devices. It has been established that the mechanical properties are scaleand-process-dependent, and hence it is essential to measure the mechanical properties of these materials at the same length scale and using the same process as that used in their usage in MEMS devices. The various experimental techniques in vogue to measure the mechanical properties of these materials are briefly reviewed. The facilities established at the Defence Metallurgical Research Laboratory, Hyderabad, and their capabilities are also highlighted.Defence Science Journal, 2009, 59(6), pp.605-615, DOI:http://dx.doi.org/10.14429/dsj.59.156

AN INVESTIGATION OF IMAGE PROCESSING TECHNIQUES FOR PAINT DEFECT DETECTION USING A MACHINE VISION SYSTEM

Detection and inspection of metal surface corrosion in the ballast tanks of U.S. Navy ships has been a long time problem. The adverse climatic conditions to which the ballast tanks are exposed and the uneven geometry of ballast tanks makes the visual inspection process of surface coatings a difficult job. Thousands of tanks are inspected yearly, with the average cost of an individual tank inspection at approximately $8-15 thousand/each. To aid the visual inspection process, this research is conducted to develop a new technique to automate the visual task of metal surface inspection by image acquisition and post processing. The best results of image processing are achieved by the enhanced contrast between the paint defect and the background using a newly developed optically active additive (OAA) used in paints. Thorough investigation of image processing algorithms has been carried out and a background of imaging theory and experiments is illustrated in this work

ANTIFUNGAL ACTIVITY OF LIPASE MODIFIED FLAVONOIDS FROM CITRUS LIMETTA

Objective: The aim of the present study is to bring about enzymatic modification of flavonoids from Citrus limetta in order to increase their antifungal activity. Methods: Methanolic extraction of flavonoids from citrus peels was carried out and their presence was confirmed by various tests. Crude extract of flavonoids was subjected to enzymatic modification by enzyme lipase in presence of acyl donor tributyrin in order to bring about esterification. Esterification was confirmed using IR spectroscopy and sodium hydroxide- phenolphthalein test. Antifungal activity of the treated sample and control sample were tested against Candida albicans and compared with fluconazole by Kirby Bauer disk diffusion method. Results: Methanolic extract showed the presence of flavonoids on carrying out various test. While testing enzymatic modification, IR spectra did not show a significant difference between treated and control; however, enhanced esterification was confirmed by sodium hydroxide-phenolphthalein test. On carrying out antifungal activity, treated samples showed a 56.52% increase in zone of inhibition against Canidida albicans as compared to the control and was also found to be more in comparison to fluconazole. Conclusion: The results signify that enzymatic modification increases the antifungal activity of flavonoids from Citrus limetta

Solar Fuels. Photocatalytic Hydrogen Generation

The necessity for developing clean energy technology has led to the surge in renewable energy research. A major effort is in discovering new approaches for producing transportable fuels. Hydrogen, which possesses the highest energy density (120 MJ/kg) known for any fuel and no carbon footprint, is regarded as the leading contender for meeting future fuel needs. The term Hydrogen Economy is often referred collectively to the topics of production, storage, and transport of hydrogen

Record catch of rock perch, Epinephelus fasciatus by bottom trawling off Ratnagiri

A productive fishing ground for rock perch (Epinephelus fasciatus) was located off Ratnagiri between 17 degree 00' to 17 degree 10' N latitude and 72 degree 20' to 72 degree 30' E longitude, around a depth of 96m during November, 1983. An average catch of 2 ton/hr. was recorded. Length frequency studies of E. fasciatus indicate the probability of a nursery ground consisting of three brood stocks. Hydrographic studies of the ground revealed that the bottom water was oxygen deficient below a strong thermocline extending from 15-75 m depth with the recorded bottom temperature amounting to 20.5 degree C

COLISTIN-CARBAPENEM COMBINATION THERAPY AGAINST CARBAPENEM RESISTANT GRAM NEGATIVE BACILLI INFECTIONS: CLINICAL AND AN IN VITRO SYNERGY STUDY

Objective: Combination therapy is recommended for carbapenem resistant Gram negative bacilli (CR GNB) infections. However, limited data exists on the clinical effectiveness of antibiotic combinations. The purpose of this study was to evaluate the efficacy of colistin-carbapenem combination against CR GNB infection in a clinical study and an in vitro synergy study using Etest. Methods: A study was conducted in a tertiary care hospital to evaluate the clinical outcome of patients with CR GNB infections who were treated with colistin-carbapenemcombination between January to April, 2013. It was comprised of 33 patients with CR GNB infection. Detection of in vitro synergy was performed by Etest for colistin-meropenem combination on five isolates. These isolates were also screened for the resistant genes blaOXA-23, blaVIMand blaNDM using single target PCR. Results: 33 CR GNB included Acinetobacterspp. (19), Pseudomonas aeruginosa (7) and Enterobacteriaceae spp. (7). Overall clinical success of 60.6% was observed in patients receiving colistin-carbapenem combination therapy. In respiratory infection, the clinical success rate was only 25%, whereas in soft tissue infection it was 57.1%. In bloodstream infection 100%  clinical success was observed. All five isolates screened using PCR was carrying bla NDM gene, whereas isolate of Acinetobacter baumannii also carried blaOXA-23 and blaVIM gene. Indifferent interactions were observed between colistin and meropenem against all five isolates. Conclusion: We observed low clinical success rate for colistin-carbapenem combination therapy, probably due to indifferent interactions between colistin and meropenem against NDM producing strain. In addition, probable pharmacokinetic concern of colistin may have a role to play

CHARACTERIZATION OF CARBAPENEM RESISTANT ACINETOBACTER BAUMANNII ISOLATED IN A TERTIARY CARE HOSPITAL: EPIDEMIOLOGY AND TREATMENT OUTCOME

Objective: Carbapenem resistant Acinetobacter baumannii (CR-Ab) has emerged as a major nosocomial pathogen, but optimal treatment regimens are unknown. Our objectives were to determine the epidemiology and outcome of CR-Ab infections at a tertiary care hospital.Methods: CR-Ab isolates were collected from January to April 2013. MICs were determined and isolates were subjected to screening for carbapenemase production by Modified Hodge test (MHT), metallo-β-lactamase (MBLs) by EDTA disk synergy test and AmpC β-lactamase by AmpC disk test. 15 isolates were subjected to PCR for detection of resistant genes, blaOXA-23, blaVIM and blaNDM. Treatment outcomes of infections were evaluated.Results: 51 CR-Ab isolates from tracheal aspirate (21), blood (15); tissue/wound/drainage (13) and urine samples (2) were collected. Colistin appeared to be the most effective agent with 98% in vitro activity. MHT showed 98% positivity, MBLs production was detected in 94.1% isolates and 64.7% were positive for AmpC β-lactamase production. All 15 isolates carried blaOXA-23 and blaVIM, of these 3 also carried blaNDM gene. Colistin containing combinations were more commonly used (68.3%). Colistin-noncarbapenem combination showed improved clinical response compared to colistin-carbapenem combination against Acinetobacter isolates carrying blaOXA-23 and blaVIM.Conclusion: A stringent infection control practice along with antimicrobial stewardship is needed to prevent emergence of Acinetobacter carrying multiple carbapenemase genes along with blaNDM. Various colistin combinations are preferentially used to treat CR-Ab infections. Identification of antimicrobial combinations with proven in vitro activity that encompass local susceptibility patterns as well as molecular mechanisms of resistance is needed to provide better outcome.Keywords: Acinetobacter baumannii, Carbapenem resistance, Carbapenemases, Colistin combination, metallo-β-lactamase, NDMÂ