834 research outputs found

    DEVELOPMENT OF NEW PYRAZOLE HYBRIDS AS ANTITUBERCULAR AGENTS: SYNTHESIS, BIOLOGICAL EVALUATION AND MOLECULAR DOCKING STUDY

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    Objective: synthesis of new 1, 3-diphenyl pyrazole derivatives 9(a-f) and 10(a-f) using molecular hybridization approach for antitubercular and cytotoxic studies.Methods: The structures of synthesized compounds were confirmed by 1H-NMR, 13C-NMR and mass spectra's. The antitubercular activity of compounds and standard drugs were assessed against Mycobacterium tuberculosis using microplate Alamar Blue assay (MABA).  The cytotoxic activities were performed by Sulforhodamine B (SRB) assay. The molecular docking and in silico ADME prediction were studied by using Schrodinger.Results: The results reveals that the compounds 9c, 9d, 10c and 10d exhibited substantial antitubercular potential with MIC < 20 μM. The cytotoxic studies revealed that the active compounds (9d, 10a, and 10d) are non-toxic to HeLa cancer cell lines with selectivity index >10. The molecular docking study was performed to study the binding orientation and affinity of synthesized compounds for InhA enzyme.Conclusion: The study explored that the 1, 3-diphenyl pyrazole hybrids coupled with well known antitubercular drugs could be a potential lead for antitubercular agents. In-silico molecular docking study helps to identify their corresponding intermolecular ligand-protein interactions with target enzyme. Also ADME prediction studies revealed that the compounds were in acceptable range to have pharmacokinetic parameters

    How managers can build trust in strategic alliances: a meta-analysis on the central trust-building mechanisms

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    Trust is an important driver of superior alliance performance. Alliance managers are influential in this regard because trust requires active involvement, commitment and the dedicated support of the key actors involved in the strategic alliance. Despite the importance of trust for explaining alliance performance, little effort has been made to systematically investigate the mechanisms that managers can use to purposefully create trust in strategic alliances. We use Parkhe’s (1998b) theoretical framework to derive nine hypotheses that distinguish between process-based, characteristic-based and institutional-based trust-building mechanisms. Our meta-analysis of 64 empirical studies shows that trust is strongly related to alliance performance. Process-based mechanisms are more important for building trust than characteristic- and institutional-based mechanisms. The effects of prior ties and asset specificity are not as strong as expected and the impact of safeguards on trust is not well understood. Overall, theoretical trust research has outpaced empirical research by far and promising opportunities for future empirical research exist

    Changes in particulate matter concentrations at different altitudinal levels with environmental dynamics

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    Ambient air quality is defined not only by the source strength but a variety of meteorological parameters as well. In the current study, ambient concentrations of PM along with temperature and relative humidity levels were monitored at seven different locations of Pakistan. A DustTrak DRX (Model 8533, TSI Inc.) was employed for twenty four hours real time monitoring of particulate matter at the selected sites. A considerable variation was observed in the 24 hour trend of particulate matter (PM) at different locations owing to variation in meteorological conditions due to different altitudes and seasons, and natural and anthropogenic sources in the vicinity. The highest average concentrations of PM2.5 (407 mu g/m(3)) were observed at highest elevation (Makra Peak, Shogran, 3089 m) while lowest averages (102 mu g/m(3)) were obtained at the seaside (Hawks Bay, Karachi, 0 m). On the other hand PMTotal fraction exhibited highest levels at site B (506 mu g/m(3)) and lowest at Site A (121 mu g/m(3)). Correlation factors were determined for PM and meteorological parameters at each location. More research needs to be conducted to have a comprehensive knowledge about the physical parameters controlling particulate dispersal at different altitudes within the country

    Evolution of the superposition of displaced number states with the two-atom multiphoton Jaynes-Cummings model: interference and entanglement

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    In this paper we study the evolution of the two two-level atoms interacting with a single-mode quantized radiation field, namely, two-atom multiphoton Jaynes-Cummings model when the radiation field and atoms are initially prepared in the superpostion of displaced number states and excited atomic states, respectively. For this system we investigate the atomic inversion, Wigner function, phase distribution and entanglement.Comment: 18 pages, 17 figure

    Changes in particulate matter concentrations at different altitudinal levels with environmental dynamics

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    Ambient air quality is defined not only by the source strength but a variety of meteorological parameters as well. In the current study, ambient concentrations of PM along with temperature and relative humidity levels were monitored at seven different locations of Pakistan. A DustTrak DRX (Model 8533, TSI Inc.) was employed for twenty four hours real time monitoring of particulate matter at the selected sites. A considerable variation was observed in the 24 hour trend of particulate matter (PM) at different locations owing to variation in meteorological conditions due to different altitudes and seasons, and natural and anthropogenic sources in the vicinity. The highest average concentrations of PM2.5 (407μg/m3 were observed at highest elevation (Makra Peak, Shogran, 3089 m) while lowest averages (102 μg/m3) were obtained at the seaside (Hawks Bay, Karachi, 0 m).On the other hand PMTotal fraction exhibited highest levels at site B (506 μg/m3) and lowest at Site A (121 μg/m3).Correlation factors were determined for PM and meteorological parameters at each location. More research needs to be conducted to have a comprehensive knowledge about the physical parameters controlling particulate dispersal at different altitudes within the country

    Casimir interaction: pistons and cavity

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    The energy of a perfectly conducting rectangular cavity is studied by making use of pistons' interactions. The exact solution for a 3D perfectly conducting piston with an arbitrary cross section is being discussed.Comment: 10 pages, 2 figures, latex2

    Revival-collapse phenomenon in the fluctuations of quadrature field components of the multiphoton Jaynes-Cummings model

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    In this paper we consider a system consisting of a two-level atom, initially prepared in a coherent superposition of upper and lower levels, interacting with a radiation field prepared in generalized quantum states in the framework of multiphoton Jaynes-Cummings model. For this system we show that there is a class of states for which the fluctuation factors can exhibit revival-collapse phenomenon (RCP) similar to that exhibited in the corresponding atomic inversion. This is shown not only for normal fluctuations but also for amplitude-squared fluctuations. Furthermore, apart from this class of states we generally demonstrate that the fluctuation factors associated with three-photon transition can provide RCP similar to that occurring in the atomic inversion of the one-photon transition. These are novel results and their consequence is that RCP occurred in the atomic inversion can be measured via a homodyne detector. Furthermore, we discuss the influence of the atomic relative phases on such phenomenon.Comment: 17 pages, 4 figure

    On the evolution of superposition of squeezed displaced number states with the multiphoton Jaynes-Cummings model

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    In this paper we discuss the quantum properties for superposition of squeezed displaced number states against multiphoton Jaynes-Cummings model (JCM). In particular, we investigate atomic inversion, photon-number distribution, purity, quadrature squeezing, Mandel QQ parameter and Wigner function. We show that the quadrature squeezing for three-photon absorption case can exhibit revivals and collapses typical to those occurring in the atomic inversion for one-photon absorption case. Also we prove that for odd number absorption parameter there is a connection between the evolution of the atomic inversion and the evolution of the Wigner function at the origin in phase space. Furthermore, we show that the nonclassical states whose the Wigner functions values at the origins are negative will be always nonclassical when they are evolving through the JCM with even absorption parameter. Also we demonstrate that various types of cat states can be generated via this system.Comment: 27 pages, 10 figure

    Dynamics, correlations and phases of the micromaser

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    The micromaser possesses a variety of dynamical phase transitions parametrized by the flux of atoms and the time-of-flight of the atom within the cavity. We discuss how these phases may be revealed to an observer outside the cavity using the long-time correlation length in the atomic beam. Some of the phase transitions are not reflected in the average excitation level of the outgoing atom, which is the commonly used observable. The correlation length is directly related to the leading eigenvalue of the time evolution operator, which we study in order to elucidate the phase structure. We find that as a function of the time-of-flight the transition from the thermal to the maser phase is characterized by a sharp peak in the correlation length. For longer times-of-flight there is a transition to a phase where the correlation length grows exponentially with the flux. We present a detailed numerical and analytical treatment of the different phases and discuss the physics behind them.Comment: 60 pages, 18 figure files, Latex + \special{} for the figures, (some redundant figures are eliminated and others are changed

    Serous cystic neoplasm of the pancreas: A multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas)

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    OBJECTIVES: Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality. DESIGN: Retrospective multinational study including SCN diagnosed between 1990 and 2014. RESULTS: 2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58\u2005years (16-99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40\u2005mm (2-200)), 9% had resection beyond 1\u2005year of follow-up (3\u2005years (1-20), size at diagnosis: 25\u2005mm (4-140)) and 39% had no surgery (3.6\u2005years (1-23), 25.5\u2005mm (1-200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1\u2005year (n=1271), size increased in 37% (growth rate: 4\u2005mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCN's related mortality was 0.1% (n=1). CONCLUSIONS: After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN
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