45 research outputs found

    PHASE MEASUREMENTS WITH A TWO-MODE SQUEEZED STATE OF LIGHT.

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    Introducing squeezed states of light into interferometers can increase the phase sensitivity of the device beyond the standard quantum limit (SQL). We discuss an SU(1,1) interferometer, where nonlinear optical elements replace the beam splitters in a Mach-Zehnder interferometer. A two-mode squeezed state of light is generated inside of such an interferometer. We talk about the phase sensitivities of an SU(1,1) interferometer with different detection schemes and their improvement over the SQL. We also discuss the concept of an optimal detection scheme for phase measurement in an interferometer. We describe a modification of the SU(1,1) interferometer which reduces the experimental complexities while giving the same phase sensitivity. We call the design a truncated SU(1,1) interferometer. We show our experimental results of 4 dB improvement in phase sensitivity over the SQL using a truncated SU(1,1) interferometer. We also compare the theoretical sensitivities of vacuum-seeded configurations of a conventional and a truncated SU(1,1) interferometer, and show our experimental results for the phase sensitivity of the truncated version. We explain the dependence of phase sensitivity on the measurement of squeezing. We talk about the methods to improve the measurement of squeezing in a 4-wave mixing experiment, and our efforts in implementing them. Finally, we mention our progress in measuring a big phase shift using an adaptive algorithm in the truncated SU(1,1) interferometer, and discuss the technicalities involved in big phase measurements

    Green synthesis of acetohydroxamic acid by thermophilic amidase of Bacillus smithii IIIMB2907

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    373-377Acetohydroxamic acid is a pharmaceutically active metal chelating agent which has various applications in the field of medicine. Current study focuses on the enzymatic synthesis of acetohydroxamic acid catalysed by thermophilic amidase from Bacillus smithii IIIMB2907. Bacterial cells were grown in 7 L fermenter for amidase production and effect of pH, temperature and substrate concentration for the biotransformation of acetamide to acetohydroxamic acid was studied. Batch reaction was also successfully optimized at bench scale with the recovery of ≈ 81% acetohydroxamic acid (purified)

    Green synthesis of acetohydroxamic acid by thermophilic amidase of Bacillus smithii IIIMB2907

    Get PDF
    Acetohydroxamic acid is a pharmaceutically active metal chelating agent which has various applications in the field of medicine. Current study focuses on the enzymatic synthesis of acetohydroxamic acid catalysed by thermophilic amidase from Bacillus smithii IIIMB2907. Bacterial cells were grown in 7 L fermenter for amidase production and effect of pH, temperature and substrate concentration for the biotransformation of acetamide to acetohydroxamic acid was studied. Batch reaction was also successfully optimized at bench scale with the recovery of ≈ 81% acetohydroxamic acid (purified)

    Coronarin K and L: Two Novel Labdane Diterpenes From Roscoea purpurea: An Ayurvedic Crude Drug

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    The main objective of cancer treatment with chemotherapy is to kill the cancerous cells without affecting the healthy normal cells. In the present study, bioactivity-guided purification of the n-chloroform soluble fraction from the methanol extract of Roscoea purpurea resulted in the identification of two new labdane diterpenes: coronarin K (1) and coronarin L (2), along with eight known compounds, coronarin A (3), bisdemethoxycurcumin (4), kaempferol 3-O-methyl ether (5), kaempferol (6), fenozan acid (7), 3-(3-methoxy,4-hydroxyphenyl)-2-propenoic acid ferulic acid (8), caffeic acid (9), and gallic acid (10). The structural identification of new compounds (1 and 2) were determined by detailed analysis of 1D (1H and 13C) and 2D NMR (COSY, HSQC, and HMBC) spectroscopic data. The relative configurations of 1 and 2 were determined with the help of NOESY correlations and comparison of optical rotations with known labdane diterpenes, with established stereochemistry, while structure of known compounds was established by direct comparison of their NMR data with those reported in the literature. This is the first report of isolation of this labdane diterpenes and phenolic classes of secondary metabolites in R. purpurea. In the preliminary screening, the methanol extract and its fractions were tested for the cytotoxic activity against a panel of four cancer cell lines (A549, HCT-116, Bxpc-3, and MCF-7); extract and its chloroform fraction were found to be active against the lung cancer cell line, A-549, with IC50 value <25 μg/ml. Owing to the notable cytotoxic activity of the chloroform fraction, the compounds (1–5) were screened for their cytotoxicity against all the cell lines by MTT assay. Coronarin K, 1 showed significant cytotoxic potential against lung cancer cell lines (A-549), with IC50 value of 13.49 μM, while other compounds did not show activity below 22 μM

    Management of bronchial carcinoid: An anaesthetic challenge

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    Carcinoid tumours pose a great challenge to anaesthesiologist, especially if carcinoid syndrome is present. We report peri-operative management of a patient with carcinoid syndrome who underwent upper lobectomy. Pre-operative optimisation for 10 days before surgery with injection octreotide and administration on the day of surgery as per guidelines was followed (North American Neuroendocrine Tumour Society guidelines). Our main goals were to prevent mediator release, avoidance of triggering factors and management of peri-operative carcinoid crisis. During tumour handling patient developed carcinoid crisis which was effectively treated with intravenous bolus octreotide and increasing rate of infusion
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