Publications by authors named "Sunita Rani"

9 Publications

  • Page 1 of 1

200-mm segmented cylindrical figured crystal for von Hamos x-ray spectrometer.

Rev Sci Instrum 2020 Jan;91(1):013101

Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, South Korea.

A von Hamos Bragg crystal spectrometer at 1C beamline of Pohang Accelerator Laboratory for x-ray emission spectroscopy (XES) is described. Diced Si crystals of different orientations ([111], [110], [100], and [311]) are glued onto a planoconcave glass substrate having 250/500 mm radius of curvature. To enhance the spectrometer efficiency, the length of the crystal analyzer is kept 200 mm. The emission spectra of Cu foil and Fe foil and elastic scattering from Al foil are measured using the von Hamos geometry in which curved crystals disperse the x-rays. Spectrometer efficiency and energy resolution are measured at various x-ray photon energies. X-rays are incident at 6.54 keV, 9.00 keV, 9.205 keV, and 11.51 keV for Si(440), Si(444), Si(800), and Si(933) crystal analyzers, respectively. The cylindrical figured analyzer is placed near 80° with respect to the sample, which gives better energy resolution. The spectrometer efficiency of the Si(444) crystal analyzer increases by ∼2 times when the length of the analyzer is increased from 100 mm to 200 mm. Furthermore, to measure Fe Kα, Kα, and K simultaneously, we made a mixed crystal analyzer in which alternative strips of Si[111] and Si[110] are glued onto one preshaped cylindrical substrate. The enhanced efficiency and simultaneous measurement of K and K emission lines will give an edge over in situ and time-resolved x-ray emission spectroscopy studies. The information extracted with a high efficiency spectrometer from low intensity XES emission lines will be useful for the in situ elemental characterization in catalytic reactions.
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http://dx.doi.org/10.1063/1.5115321DOI Listing
January 2020

Design, synthesis and biological evaluation of chalconyl blended triazole allied organosilatranes as giardicidal and trichomonacidal agents.

Eur J Med Chem 2016 Jan 2;108:287-300. Epub 2015 Dec 2.

Centre for Nano-science and Nano-technology, Panjab University, Chandigarh, 160014, India.

A series of chalconyl blended triazole allied silatranes (7a-g/8a-g/9a-g) were synthesized in good yields using a simple, economical and biocompatible synthetic route. The blend of three different pharmacologically active moieties into a single scaffold resulted into synergistic effect in their bio-activity. Various substitutions were tried to study the structure activity relationship (SAR) of the synthesized compounds on the basis of biological results. All the newly synthesized compounds were well characterized by IR, (1)H and (13)C NMR, low resolution mass spectroscopy and elemental analysis. The structures of 7a and 7c were authenticated by single crystal X-ray crystallography. These compounds were screened by using Molinspiration software for their physicochemical properties and all the compounds showed good oral bioavailability. The antiparasitic activity of the newly synthesized compounds was evaluated against unicellular parasites (Giardia lamblia and Trichomonas vaginalis) in comparison to standard drug (metronidazole) by 3-(4,5-dimethylthiazol-yl)-diphenyl tetrazolium bromide (MTT) assay. All the compounds displayed significant activity against G. lamblia and T. vaginalis with IC50 values ranging from 19.58-131.2 μM to 18.24-101.26 μM respectively. The entire library of compounds was found to be more active than metronidazole except 9a, 9f and 9g. Notably, 9e and 7e were found to be most significant against G. lamblia and T. vaginalis respectively.
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http://dx.doi.org/10.1016/j.ejmech.2015.11.029DOI Listing
January 2016

Effect of dexmedetomidine as an adjuvant to levobupivacaine in supraclavicular brachial plexus block: A randomized double-blind prospective study.

J Anaesthesiol Clin Pharmacol 2015 Jul-Sep;31(3):333-8

Department of Anaesthesia, GGS Medical College and Hospital, Faridkot, Punjab, India.

Background And Aims: Regional anesthesia is a recommended technique for upper and lower limb surgeries with better postoperative profile. In this, randomized, double-blind study, we evaluated the effectiveness of the addition of dexmedetomidine to varying concentration of levobupivacaine for supra clavicular brachial plexus block.

Material And Methods: After obtaining ethical Committee approval, a double-blind, randomized prospective clinical study was conducted on 90 American Society of Anesthesiologist Grade I and II patients in the age group of 18-55 years, divided randomly into two groups: Group A received 40 ml of solution containing 30 ml 0.5% levobupivacaine and 10 ml 1% lignocaine and group B received 40 ml of solution containing 30 ml 0.25% levobupivacaine and 10 ml 1% lignocaine with dexmedetomidine 1 microg/kg for supraclavicular brachial plexus block. Besides effectiveness, other parameters observed were: duration of sensory blockade; onset and duration of motor blockade; duration of postoperative analgesia; and patient satisfaction score.

Results: Onset of sensory and motor blockade was 7.6 ± 1.006 min and 8.3 ± 0.877 min in group A, while it was 6.96 ± 1.077 min an 7.6 ± 1.1 min in group B, respectively. The difference was statistically significant (P < 0.05). Duration of sensory block was 8.5 ± 0.77 h in group A and 8.5 ± 0.98 in group B (P > 0.05). Duration of motor block was 8.45 ± 0.75 h in group A and 5.6 ± 0.98 in group B (P < 0.05). Duration of analgesia was 8.5 ± 0.77 h in group A and 9.2 ± 1.05 in group B (P < 0.05).

Conclusion: Addition of 1 microg/kg dexmedetomidine to 0.25% levobupivacaine for supraclaviclar plexus block shortens sensory, motor block onset time and motor block durations, extends sensory block, and analgesia durations. Reduction in total levobupivacaine dose also increases the safety margin of the block.
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http://dx.doi.org/10.4103/0970-9185.161668DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4541179PMC
September 2015

Rapid plasma reagin test: High false positivity or important marker of high risk behavior.

Asian J Transfus Sci 2015 Jan-Jun;9(1):109

Department of Blood Bank, Dr. Ram Manohar Lohia Hospital, New Delhi, India.

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http://dx.doi.org/10.4103/0973-6247.150979DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4339923PMC
February 2015

Study of optical phase conjugation in amorphous Zn(x)-S(y)-Se(100-x-y) chalcogenide thin films using degenerate four-wave mixing.

Spectrochim Acta A Mol Biomol Spectrosc 2014 Jan 27;118:733-6. Epub 2013 Sep 27.

Laser Laboratory, Department of Applied Physics, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana, India. Electronic address:

Degenerate four-wave mixing (DFWM) experiment is performed to obtain light wavefront inversion (phase conjugation) in semiconducting chalcogenide thin films. Third order nonlinearity of amorphous Zn(x)-S(y)-Se(100-x-y) chalcogenide thin films using DFWM technique is studied at second harmonic of Nd:YAG laser. Influence of total input irradiance on phase conjugate signal is deliberated using log-log plot that has a slope of three and hence implies third order nonlinearity. The dependence of phase conjugate signal on forward beam and backward beam is also studied. The period of the grating formed by interference of forward and probe beam is determined. As the temporal overlapping and sample thickness conditions are satisfied, the third order nonlinear susceptibility, figure of merit and nonlinear refractive index of amorphous films are estimated. The nonlinear behavior is analyzed in terms of decrease in band gap with increasing Zinc and decreasing Sulfur content.
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http://dx.doi.org/10.1016/j.saa.2013.09.038DOI Listing
January 2014

Fabrication of a cytochrome c biosensor based on cytochrome oxidase/NiO-NPs/cMWCNT/PANI modified Au electrode.

J Biomed Nanotechnol 2013 Mar;9(3):409-16

Department of Biochemistry, M.D. University, Rohtak 124001, India.

An amperometric biosensor for determination of Cytochrome c (Cyt c) was fabricated by immobilizing Cytochrome c oxidase (COx) onto nickel oxide nanoparticles (NiO-NPs) decorated carboxylated multiwalled carbon nanotubes/polyaniline (NiO-NPs/cMWCNT/PANI) film electrodeposited on the surface of a gold (Au) electrode. The electrochemical characteristics of immobilized COx were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), Scanning Electron Microscopy (SEM) and Fourier transform Infra-red spectroscopy (FTIR). Cyclic voltammetric (CV) studies of the electrode at different stages of construction of enzyme electrode demonstrated that the modified Au electrode had enhanced electrochemical oxidation of H2O2, which offers a number of attractive features to develop amperometric biosensors based on split of H2O2. There was a good linear relationship between the current (mA) and Cyt c concentration in the range 5 x 10(-12) M to 5 x 10(-7) M. The sensor had a detection limit of 5 x 10(-12) M (S/N = 3) with a high sensitivity of 3.7 mA cm(-2) nM(-1). The sensor gave accurate and satisfactory results, when employed for determination of Cyt c in different serum samples.
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http://dx.doi.org/10.1166/jbn.2013.1549DOI Listing
March 2013

Sensitive measurement of optical nonlinearity in amorphous chalcogenide materials in nanosecond regime.

Spectrochim Acta A Mol Biomol Spectrosc 2012 Jul 3;93:135-9. Epub 2012 Mar 3.

Laser Laboratory, Department of Applied Physics, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana, India.

The present work focuses on the nonlinear optical behavior of chalcogenide As(2)S(3) film as well as on bulk material. The thin film of As(2)S(3) grown by thermal evaporation and bulk glass developed by melt-quenched technique has been characterized using nanosecond pulses of Nd:YAG (532 nm) and Nd:YVO(4) (1,064 nm) laser. Using Z-scan technique, the laser induced nonlinear optical parameters viz. nonlinear refractive index (n(2)), nonlinear absorption coefficient (β) and third order nonlinear susceptibility (χ(3)) have been estimated. At 1,064 nm excitation, the materials exhibit stronger nonlinearity as compared to that of 532 nm laser. In case of As(2)S(3) thin film, observed nonlinearity attributes to two-photon absorption. The optical limiting response of chalcogenide film as well as bulk sample has also been reported. The study predicts that the As(2)S(3) thin film is a better optical limiting material than bulk glass due to relatively higher nonlinearity and lower limiting threshold.
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http://dx.doi.org/10.1016/j.saa.2012.02.093DOI Listing
July 2012

Phytochemical investigation of the seeds of Althea officinalis L.

Nat Prod Res 2010 Sep;24(14):1358-64

Department of Pharmaceutical Chemistry, Jamia Hamdard (Hamdard University), New Delhi 110062, India.

Phytochemical investigation of the seeds of Althea officinalis L. (Malvaceae) led to the isolation of three new phytoconstituents, identified as n-hexacos-2-enyl-1,5-olide (altheahexacosanyl lactone), 2beta-hydroxycalamene (altheacalamene) and 5,6-dihydroxycoumarin-5-dodecanoate-6beta-D-glucopyranoside (altheacoumarin glucoside), along with the known phytoconstituents lauric acid, beta-sitosterol and lanosterol. The structures of these compounds were established on the basis of spectral analysis and chemical reactions.
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http://dx.doi.org/10.1080/14786411003650777DOI Listing
September 2010

Preparation and partial characterization of collagen sheet from fish (Lates calcarifer) scales.

Int J Biol Macromol 2008 Jan 26;42(1):6-9. Epub 2007 Aug 26.

Central Leather Research Institute, Adyar, Chennai 96, India.

Fish scales, which are hitherto discarded as waste, were collected and cleaned thoroughly. The scales were hydrolyzed under controlled acidic conditions, neutralized and made in to a sheet, i.e., fish scale collagen sheet (FCS). The FCS was characterized for its infrared spectroscopy (IR), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), and mechanical properties. The IR study has shown that the sheet contains both organic and inorganic phases revealing that the scales are partially deminaralized. The tensile strength of FCS is enough if it is used as a wound dressing material. The SEM studies have shown that FCS is porous and exhibited fibrous nature.
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http://dx.doi.org/10.1016/j.ijbiomac.2007.08.003DOI Listing
January 2008