1,407 research outputs found

    A Validated Reversed-Phase HPLC Method for the Determination of Atorvastatin Calcium in Tablets

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    A Reversed-Phase Liquid Chromatographic (RP-LC) assay method was developed for the quantitative determination of atorvastatin calcium in the presence of its degradation products. The assay involved an isocratic elution of atorvastatin calcium in a LiChroCARTR 250*4 mm HPLC Cartridge LiChrospherR 100 RP-18 (5 ÎŒm) column using a mobile phase consisting of 0.1% acetic acid solution: acetonitrile (45:55, v/v), pH = 3.8. The flow rate was 0.8 mL/min and the analytes monitored at 246 nm. The assay method was found to be linear from 8.13 to 23.77 ÎŒg/mL. All the validation parameters were within the acceptance range. The developed method was successfully applied to estimate the amount of atorvastatin calcium in tablets.Fil: Simionato, Laura Daniela. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂ­mica. Departamento de TecnologĂ­a FarmacĂ©utica; ArgentinaFil: Ferello, L.. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂ­mica. Departamento de TecnologĂ­a FarmacĂ©utica; ArgentinaFil: Stamer. S.. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂ­mica. Departamento de TecnologĂ­a FarmacĂ©utica; ArgentinaFil: Repetto, M. F.. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂ­mica. Departamento de TecnologĂ­a FarmacĂ©utica; ArgentinaFil: Zubata, P. D.. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂ­mica. Departamento de TecnologĂ­a FarmacĂ©utica; ArgentinaFil: Segall, Adriana Ines. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂ­mica. Departamento de TecnologĂ­a FarmacĂ©utica; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay; Argentin

    Efficienza dei servizi sanitari ed utilizzo ottimale delle risorse. Una applicazione al Policlinico Universitario di Cagliari

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    l’applicazione del nomogramma di Barber, che puĂČ essere impiegato nel controllo della gestione di un dato reparto ospedaliero considerando le diverse patologie (DRG) che ad esso afferiscono sia per effettuare analisi di tipo descrittivo e/o investigativo relativamente ai singoli DRG sia per condurre indagini diacroniche finalizzate a cogliere quali siano state le variazioni del livello di efficienza nel corso del tempo dei reparti e/o delle varie patologie. In ultima analisi l’utilizzazione del modello quale strumento di valutazione della gestione delle attivitĂ  sanitarie

    Measurement of the Permanent Electric Dipole Moment of the 129^{129}Xe Atom

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    We report on a new measurement of the CP-violating permanent Electric Dipole Moment (EDM) of the neutral 129^{129}Xe atom. Our experimental approach is based on the detection of the free precession of co-located nuclear spin-polarized 3^3He and 129^{129}Xe samples. The EDM measurement sensitivity benefits strongly from long spin coherence times of several hours achieved in diluted gases and homogeneous weak magnetic fields of about 400~nT. A finite EDM is indicated by a change in the precession frequency, as an electric field is periodically reversed with respect to the magnetic guiding field. Our result, (−4.7±6.4)⋅10−28\left(-4.7\pm6.4\right)\cdot 10^{-28} ecm, is consistent with zero and is used to place a new upper limit on the 129^{129}Xe EDM: ∣dXe∣<1.5⋅10−27|d_\text{Xe}|<1.5 \cdot 10^{-27} ecm (95% C.L.). We also discuss the implications of this result for various CP-violating observables as they relate to theories of physics beyond the standard model

    The Formation of Cataclysmic Variables: The Influence of Nova Eruptions

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    The theoretical and observed populations of pre-cataclysmic variables are dominated by systems with low-mass white dwarfs (WDs), while the WD masses in cataclysmic variables (CVs) are typically high. In addition, the space density of CVs is found to be significantly lower than in the theoretical models. We investigate the influence of nova outbursts on the formation and initial evolution of CVs. In particular, we calculate the stability of the mass transfer in the case where all of the material accreted on the WD is lost in classical novae and part of the energy to eject the material comes from a common-envelope-like interaction with the companion. In addition, we study the effect of an asymmetry in the mass ejection that may lead to small eccentricities in the orbit. We find that a common-envelope-like ejection significantly decreases the stability of the mass transfer, particularly for low-mass WDs. Similarly, the influence of asymmetric mass loss can be important for short-period systems and even more so for low-mass WDs; however, this influence likely disappears long before the next nova outburst due to orbital circularization. In both cases the mass-transfer rates increase, which may lead to observable (and perhaps already observed) consequences for systems that do survive to become CVs. However, a more detailed investigation of the interaction between nova ejecta and the companion and the evolution of slightly eccentric CVs is needed before definite conclusions can be drawn

    The ePetri dish, an on-chip cell imaging platform based on subpixel perspective sweeping microscopy (SPSM)

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    We report a chip-scale lensless wide-field-of-view microscopy imaging technique, subpixel perspective sweeping microscopy, which can render microscopy images of growing or confluent cell cultures autonomously. We demonstrate that this technology can be used to build smart Petri dish platforms, termed ePetri, for cell culture experiments. This technique leverages the recent broad and cheap availability of high performance image sensor chips to provide a low-cost and automated microscopy solution. Unlike the two major classes of lensless microscopy methods, optofluidic microscopy and digital in-line holography microscopy, this new approach is fully capable of working with cell cultures or any samples in which cells may be contiguously connected. With our prototype, we demonstrate the ability to image samples of area 6 mm × 4 mm at 660-nm resolution. As a further demonstration, we showed that the method can be applied to image color stained cell culture sample and to image and track cell culture growth directly within an incubator. Finally, we showed that this method can track embryonic stem cell differentiations over the entire sensor surface. Smart Petri dish based on this technology can significantly streamline and improve cell culture experiments by cutting down on human labor and contamination risks

    Evaluation of the program ‘understanding and learning in the classroom’

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    We present the program “understanding and learning in the classroom” centered on the improvement of reading comprehension strategies. We present also an evaluation of this program
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