4,645 research outputs found

    A VALIDATED STABILITY INDICATING RP-HPLC METHOD FOR THE SIMULTANEOUS DETERMINTION OF ATORVASTATIN CALCIUM AND EZETIMIBE HYDROCHLORIDE IN BULK AND TABLET DOSAGE FORM

    Get PDF
    Objective: To develop a simple, selective and precise stability indicating reverse-phase high performance liquid chromatography method for the simultaneous estimation of atorvastatin calcium and ezetimibe hydrochloride in bulk and tablet dosage form.Methods: The chromatographic separation was performed by Agilent Zorbax column (250×4.6 mm, 5 µm) using methanol: 0.1 % v/v orthophosphoric acid in water (65:35) as mobile phase at flow rate of 1.0 ml/min with injection volume 20 µl and the detection was carried out using UV detector at 240 nm. The method was validated as per ICH guidelines.Results: The retention time for atorvastatin calcium (ATV) and ezetimibe hydrochloride (EZT) was found to be 6.81 min and 4.96 min respectively. The linear regression analysis data for the calibration plots showed good linear relationship in the concentration range of 5-50 µg/ml for both ATV and EZT. The percentage recoveries of ATV and EZT in the marketed dosage form were found to be 100.82 and 94.27 respectively. The correlation coefficients for ATV and EZT were 0.9983 and 0.998 respectively. The percentage degradation at different stress conditions like acid, alkaline, oxidative and photolytic for atorvastatin calcium were found to be 14.91, 8.26, 8.02 and 2.65 respectively and for ezetimibe hydrochloride, found to be 9.70, 32.18, 2.51 and 0.16 respectively.Conclusion: The developed method was successfully validated as per ICH guidelines. This method is simple, selective, linear, precise, accurate and sensitive, and can be used for routine analysis of tablet dosage forms containing both the drugs.Keywords: Atorvastatin calcium, Ezetimibe hydrochloride, RP-HPLC, Stress degradatio

    Modular detergents tailor the purification and structural analysis of membrane proteins including G-protein coupled receptors

    Get PDF
    Detergents enable the purification of membrane proteins and are indispensable reagents instructural biology. Even though a large variety of detergents have been developed in the lastcentury, the challenge remains to identify guidelines that allowfine-tuning of detergents forindividual applications in membrane protein research. Addressing this challenge, here weintroduce the family of oligoglycerol detergents (OGDs). Native mass spectrometry (MS)reveals that the modular OGD architecture offers the ability to control protein purificationand to preserve interactions with native membrane lipids during purification. In addition to abroad range of bacterial membrane proteins, OGDs also enable the purification and analysisof a functional G-protein coupled receptor (GPCR). Moreover, given the modular design ofthese detergents, we anticipatefine-tuning of their properties for specific applications instructural biology. Seen from a broader perspective, this represents a significant advance forthe investigation of membrane proteins and their interactions with lipids

    Casein haplotype structure in five Italian goat breeds

    Get PDF
    The aim of this work was to investigate the genetic structure of the casein gene cluster in 5 Italian goat breeds and to evaluate the haplotype variability within and among populations. A total of 430 goats from Vallesana, Roccaverano, Jonica, Garganica, and Maltese breeds were genotyped at alphas1-casein (CSN1S1), alphas2-casein, (CSN1S2), beta-casein (CSN2), and kappa-casein (CSN3) loci using several genomic techniques and milk protein analysis. Casein haplotype frequencies were estimated for each breed. Principal component analysis was carried out to highlight the relationship among breeds. Allele and haplotype distributions indicated considerable differences among breeds. The haplotype CSN1S1*F- CSN1S2*F-CSN3*D occurred in all breeds with frequencies >0.100 and was the most common haplotype in the Southern breeds. A high frequency of CSN1S1*0-CSN1S2*C-CSN3*A haplotype was found in Vallesana population (0.162). Principal component analysis clearly separated the Northern and Southern breeds by the first component. The variability of the caprine casein loci and variety of resulting haplotypes should be exploited in the future using specific breeding programs aiming to preserve biodiversity and to select goat genetic lines for specific protein production

    Operational experience, improvements, and performance of the CDF Run II silicon vertex detector

    Full text link
    The Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and the end of operations in September 2011, the Tevatron delivered 12 fb-1 of integrated luminosity of p-pbar collisions at sqrt(s)=1.96 TeV. Many physics analyses undertaken by CDF require heavy flavor tagging with large charged particle tracking acceptance. To realize these goals, in 2001 CDF installed eight layers of silicon microstrip detectors around its interaction region. These detectors were designed for 2--5 years of operation, radiation doses up to 2 Mrad (0.02 Gy), and were expected to be replaced in 2004. The sensors were not replaced, and the Tevatron run was extended for several years beyond its design, exposing the sensors and electronics to much higher radiation doses than anticipated. In this paper we describe the operational challenges encountered over the past 10 years of running the CDF silicon detectors, the preventive measures undertaken, and the improvements made along the way to ensure their optimal performance for collecting high quality physics data. In addition, we describe the quantities and methods used to monitor radiation damage in the sensors for optimal performance and summarize the detector performance quantities important to CDF's physics program, including vertex resolution, heavy flavor tagging, and silicon vertex trigger performance.Comment: Preprint accepted for publication in Nuclear Instruments and Methods A (07/31/2013

    Composite Oncocytoma and Papillary Renal Cell Carcinoma of the Kidney Treated by Partial Nephrectomy: A Case Report

    Get PDF
    We present the case of a 73-year-old woman who presented with lethargy and a nonproductive cough. Computerised tomography of her abdomen revealed a 38-mm mass in the lower pole of her left kidney. She underwent a partial nephrectomy, with final histopathological analysis confirming the presence of a concomitant oncocytoma and papillary cell carcinoma. To our knowledge, this is the only case report in the world literature describing a papillary renal cell carcinoma within an oncocytoma treated by partial nephrectomy

    Silicon photonics in Pirelli

    Get PDF
    Silicon is the dominant material in the microelectronic industry and silicon photonics is rapidly gaining importance as a technological platform for a wide range of applications in telecom, and optical interconnect. It allows the implementation of many photonic functions through the use of wafer-scale technologies normally used for advanced CMOS-processing. In this paper some of the most important issues toward a practical implementation of Silicon photonics into an industrial device will be addressed: low loss waveguides, polarization handling, tunability, hitless switching. A tunable Add-Drop multiplexer has been chosen as a case Study of a fully integrated device

    Modular detergents tailor the purification and structural analysis of membrane proteins including G-protein coupled receptors

    Get PDF
    Detergents enable the purification of membrane proteins and are indispensable reagents in structural biology. Even though a large variety of detergents have been developed in the last century, the challenge remains to identify guidelines that allow fine-tuning of detergents for individual applications in membrane protein research. Addressing this challenge, here we introduce the family of oligoglycerol detergents (OGDs). Native mass spectrometry (MS) reveals that the modular OGD architecture offers the ability to control protein purification and to preserve interactions with native membrane lipids during purification. In addition to a broad range of bacterial membrane proteins, OGDs also enable the purification and analysis of a functional G-protein coupled receptor (GPCR). Moreover, given the modular design of these detergents, we anticipate fine-tuning of their properties for specific applications in structural biology. Seen from a broader perspective, this represents a significant advance for the investigation of membrane proteins and their interactions with lipids

    A collection of primary tissue cultures of tumors from vacuum packed and cooled surgical specimens: a feasibility study

    Get PDF
    Primary cultures represent an invaluable tool to set up functional experimental conditions; however, creation of tissue cultures from solid tumors is troublesome and often unproductive. Several features can affect the success rate of primary cultures, including technical issues from pre-analytical procedures employed in surgical theaters and pathology laboratories. We have recently introduced a new method of collection, transfer, and preservation of surgical specimens that requires immediate vacuum sealing of excised specimens at surgical theaters, followed by time-controlled transferring at 4°C to the pathology laboratory. Here we investigate the feasibility and performance of short-term primary cell cultures derived from vacuum packed and cooled (VPAC) preserved tissues. Tissue fragments were sampled from 52 surgical specimens of tumors larger than 2 cm for which surgical and VPAC times (the latter corresponding to cold ischemia time) were recorded. Cell viability was determined by trypan blue dye-exclusion assay and hematoxylin and eosin and immunohistochemical stainings were performed to appreciate morphological and immunophenotypical features of cultured cells. Cell viability showed a range of 84-100% in 44 out of 52 (85%) VPAC preserved tissues. Length of both surgical and VPAC times affected cell viability: the critical surgical time was set around 1 hour and 30 minutes, while cells preserved a good viability when kept for about 24 hours of vacuum at 4°C. Cells were maintained in culture for at least three passages. Immunocytochemistry confirmed the phenotype of distinct populations, that is, expression of cytokeratins in epithelioid cells and of vimentin in spindle cells. Our results suggest that VPAC preserved tissues may represent a reliable source for creation of primary cell cultures and that a careful monitoring of surgical and cold ischemia times fosters a good performance of primary tissue cultures

    Evidence for the exclusive decay Bc+- to J/psi pi+- and measurement of the mass of the Bc meson

    Get PDF
    We report first evidence for a fully reconstructed decay mode of the B_c^{\pm} meson in the channel B_c^{\pm} \to J/psi \pi^{\pm}, with J/psi \to mu^+mu^-. The analysis is based on an integrated luminosity of 360 pb$^{-1} in p\bar{p} collisions at 1.96 TeV center of mass energy collected by the Collider Detector at Fermilab. We observe 14.6 \pm 4.6 signal events with a background of 7.1 \pm 0.9 events, and a fit to the J/psi pi^{\pm} mass spectrum yields a B_c^{\pm} mass of 6285.7 \pm 5.3(stat) \pm 1.2(syst) MeV/c^2. The probability of a peak of this magnitude occurring by random fluctuation in the search region is estimated as 0.012%.Comment: 7 pages, 3 figures. Version 3, accepted by PR

    Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt(s) = 1.96 TeV

    Get PDF
    We present a measurement of the top quark pair production cross section in ppbar collisions at sqrt(s)=1.96 TeV using 318 pb^{-1} of data collected with the Collider Detector at Fermilab. We select ttbar decays into the final states e nu + jets and mu nu + jets, in which at least one b quark from the t-quark decays is identified using a secondary vertex-finding algorithm. Assuming a top quark mass of 178 GeV/c^2, we measure a cross section of 8.7 +-0.9 (stat) +1.1-0.9 (syst) pb. We also report the first observation of ttbar with significance greater than 5 sigma in the subsample in which both b quarks are identified, corresponding to a cross section of 10.1 +1.6-1.4(stat)+2.0-1.3 (syst) pb.Comment: Accepted for publication in Physics Review Letters, 7 page
    corecore