155 research outputs found

    Spectrophotometric Assay of Phenylephrine Hydrochloride Using 4-Aminoantipyrine and Copper (II)

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    A new spectrophotometric method is proposed for determination of phenylephrine hydrochloride. The method is based on the coupling of 4-aminoantipyrine (4-AAP) with phenylephrine hydrochloride (PEH) to give a new ligand that reacts with copper (II) in the presence of sodium tetraborate buffer solution of pH 9.00 at 50 °C to give an intense red colored chelate having maximum absorption at 480 nm. The optimization of the experimental conditions is described. The method has been used for the determination of 2.0–50.0 μg/ml of PEH. The molar absorptivity is 5.34×103 L.mol.-1cm.-1 and the accuracy of the method is achieved by the value of average recovery (101.28 %) and the precision is supported by relative standard deviation (RSD=1.25 %) values. The results of the method was compared with those of the standard method. The interference of excipients was studied. The mechanism of the chemical reaction has been proposed. The proposed method was successfully applied for the determination of the PEH in pharmaceutical syrup formulations

    Star Formation in the vicinity of Nuclear Black Holes: Young Stellar Objects close to Sgr A*

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    It is often assumed that the strong gravitational field of a super-massive black hole disrupts an adjacent molecular cloud preventing classical star formation in the deep potential well of the black hole. Yet, young stars have been observed across the entire nuclear star cluster of the Milky Way including the region close (<<0.5~pc) to the central black hole, Sgr A*. Here, we focus particularly on small groups of young stars, such as IRS 13N located 0.1 pc away from Sgr A*, which is suggested to contain about five embedded massive young stellar objects (<<1 Myr). We perform three dimensional hydrodynamical simulations to follow the evolution of molecular clumps orbiting about a 4×106 M⊙4\times10^6~M_{\odot} black hole, to constrain the formation and the physical conditions of such groups. The molecular clumps in our models assumed to be isothermal containing 100 M⊙M_{\odot} in <<0.2 pc radius. Such molecular clumps exist in the circumnuclear disk of the Galaxy. In our highly eccentrically orbiting clump, the strong orbital compression of the clump along the orbital radius vector and perpendicular to the orbital plane causes the gas densities to increase to values higher than the tidal density of Sgr A*, which are required for star formation. Additionally, we speculate that the infrared excess source G2/DSO approaching Sgr A* on a highly eccentric orbit could be associated with a dust enshrouded star that may have been formed recently through the mechanism supported by our models.Comment: 18 pages, 11 figures, accepted for publication in MNRA

    Spectrophotometric Assay of some Nitrogen Containing Drugs in Pharmaceutical Formulations using p-Chloranilic Acid Reagent

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    A spectrophotometric method is developed for the determination of some drugs containing amino groups (sulfacetamide sodium, lidocaine and terbutaline sulfate) based on their reaction with p-chloranilic acid reagent in an organic medium forming colored charge transfer complexes. The complexes have maximum absorptions at 530 and 527 nm for sulfacetamide sodium and lidocaine respectively, but terbutaline sulfate gave two maximum absorptions at 529 and 319 nm. Beers law is obeyed over the concentration range of 10-60 µg.ml-1 for sulfacetamide sodium and lidocaine and 5-70 µg.ml-1 for terbutaline sulfate. The molar absorptivity values are 0.94—103, 0.913—103 L.mol-1.cm-1 for sulfacetamide sodium and lidocaine respectively while terbutaline sulfate gave 0.987—103 L.mol-1.cm-1 at 529 nm and 7.407—103 L.mol-1.cm-1 at 319 nm with accuracy range between 100.20% and 101.42% and RSD better than 3.15% for all drugs. The method is applied successfully for determination of these drugs in pharmaceutical formulations and compared favorably with British Pharmacopeia standard methods. F and t tests are less than the tabulated values at 95% confidence level

    A new bow-shock source with bipolar morphology in the vicinity of Sgr A*

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    Here we present a new bowshock blue-shifted source in the close vicinity of Sgr A* that we name X8. We use data-sets that are based on SINFONI observations with the Very Large Telescope. We can trace the source between 2006 and 2016 in the blue-shifted line maps and it shows not only positional similarities to X7 but also the same spectral footprint. The symmetry axis of both extended sources points towards Sgr A* and exhibits [Fe III] emission lines that arise due to wind-wind shocks. In particular, the source X8 has a bipolar morphology, which makes it the closest bipolar source in the vicinity of Sgr A*. In addition, we can trace a K-band continuum counterpart of X8. This points towards a stellar counterpart to the line-map emission. Overall, the source X8 can be interpreted as either a Young Stellar Object or a young planetary nebula, which makes this source unique among so-far detected main-sequence OB stars in this region.Comment: Accepted for publication by A&A, 15 pages, 13 figure

    Spectrophotometric Determination of Catecholamine Containing Drugs Using Calcon Dye

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    Calcon dye has been used for spectrophotometric determination of catecholamine-containing drugs, namely, adrenaline, methyldopa and dopamine in their pure forms and pharmaceutical formulations. The method is based on the oxidation of the above drugs with an excess of N-bromosuccinimide (NBS) in an acidic medium. The residual oxidizing agent bleaches the blackish-brown color of calcon measured at 510 nm. The decolorization of the dye is proportional to the residual amount of NBS, which is proportional to the concentration of the drug. Linear calibration graphs were obtained in the concentration range 0.5-16.0, 2.0-40.0 and 1.036.0 μgmL-1 with molar absorptivity values 1.10×104, 3.2×103 and 4.3×103 Lmol-1cm-1 for above drugs, respectively. The method is simple, sensitive, accurate, precise and free from excipients. The developed method was successfully applied to determine the drugs in their pharmaceutical formulations

    Naturally occurring ingredients as potential antiaging cosmetics

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    The criteria adopted for establishing whether a determined substance has potential as a cosmetic constituent are based on the present legislation of each country. In this study, natural antiaging constituents as Fomes officinalis, rice protein and glutamic acid were pharmacologically evaluated using neuromuscular preparation. These constituents induced a neuromuscular blockade, individually and also in mixture, simulating a Botox®, but not, dimethylaminoethanol-effect. The pharmacological knowledge is beneficial since the real effect of each ingredient becomes apparent, increasing the consumer's confidence on the antiaging cosmetic.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Host galaxies of merging compact objects: mass, star formation rate, metallicity, and colours

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    Characterizing the properties of the host galaxies of merging compact objects provides essential clues to interpret current and future gravitational-wave detections. Here, we investigate the stellar mass, star formation rate (SFR), metallicity, and colours of the host galaxies of merging compact objects in the local Universe by combining the results of MOBSE population-synthesis models together with galaxy catalogues from the EAGLE simulation. We predict that the stellar mass of the host galaxy is an excellent tracer of the merger rate per galaxy n(GW) of double neutron stars (DNSs), double black holes (DBHs), and black hole-neutron star binaries (BHNSs). We find a significant correlation also between n(GW) and SFR. As a consequence, n(GW) correlates also with the r-band luminosity and with the g-r colour of the host galaxies. Interestingly, greater than or similar to 60 per cent, greater than or similar to 64 per cent, and greater than or similar to 73 per cent of all the DNSs, BHNSs, and DBHs merging in the local Universe lie in early-type galaxies, such as NGC 4993. We predict a local DNS merger rate density of similar to 238 Gpc(-3) yr(-1) and a DNS merger rate similar to 16-121 Myr(-1) for Milky Way-like galaxies. Thus, our results are consistent with both the DNS merger rate inferred from GW170817 and the one inferred from Galactic DNSs

    Naturally occurring ingredients as potential antiaging cosmetics

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    The criteria adopted for establishing whether a determined substance has potential as a cosmetic constituent are based on the present legislation of each country. In this study, natural antiaging constituents as Fomes officinalis, rice protein and glutamic acid were pharmacologically evaluated using neuromuscular preparation. These constituents induced a neuromuscular blockade, individually and also in mixture, simulating a Botox®, but not, dimethylaminoethanol-effect. The pharmacological knowledge is beneficial since the real effect of each ingredient becomes apparent, increasing the consumer's confidence on the antiaging cosmetic.Colegio de Farmacéuticos de la Provincia de Buenos Aire
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