1,456 research outputs found
Dissecting Photometric Redshift for Active Galactic Nucleus Using XMM- and Chandra-COSMOS Samples
In this paper, we release accurate photometric redshifts for 1692 counterparts to Chandra sources in the central square degree of the Cosmic Evolution Survey (COSMOS) field. The availability of a large training set of spectroscopic redshifts that extends to faint magnitudes enabled photometric redshifts comparable to the highest quality results presently available for normal galaxies. We demonstrate that morphologically extended, faint X-ray sources without optical variability are more accurately described by a library of normal galaxies (corrected for emission lines) than by active galactic nucleus (AGN) dominated templates, even if these sources have AGN-like X-ray luminosities. Preselecting the library on the bases of the source properties allowed us to reach an accuracy σ_(Δz/(1+z(spec))~0.015 with a fraction of outliers of 5.8% for the entire Chandra-COSMOS sample. In addition, we release revised photometric redshifts for the 1735 optical counterparts of the XMM-detected sources over the entire 2 deg^2 of COSMOS. For 248 sources, our updated photometric redshift differs from the previous release by Δz > 0.2. These changes are predominantly due to the inclusion of newly available deep H-band photometry (H_(AB) = 24 mag). We illustrate once again the importance of a spectroscopic training sample and how an assumption about the nature of a source together, with the number and the depth of the available bands, influences the accuracy of the photometric redshifts determined for AGN. These considerations should be kept in mind when defining the observational strategies of upcoming large surveys targeting AGNs, such as eROSITA at X-ray energies and the Australian Square Kilometre Array Pathfinder Evolutionary Map of the Universe in the radio band
Unitarity and the color confinement
We discuss how confinement property of QCD results in the rational
unitarization scheme and how unitarity saturation leads to appearance of a
hadron liquid phase at very high temperatures.Comment: 10 pages, no figire
FORMULATION AND DEVELOPMENT OF TOPICAL ANTI ACNE FORMULATION OF SPIRULINA EXTRACT
Objective: The objective of this research was to formulate and evaluate anti-acne ointment of C-phycocyanin(C-PC) extracted from spirulina.Methods: C-PC was successfully extracted from spirulina by using sonication and cold-maceration process and further purified by dialysis method. By employing disc diffusion and agar dilution method, antimicrobial activity and minimum inhibitory concentration(MIC) of C-PC as determined against Propionibacterium acne (P. acne) and Staphylococcus epidermidis(S. epidermidis). Further, the two different formulations were prepared by using water soluble and oleaginous bases, and the formulations were characterized for particle size, viscosity, pH, consistency, drug diffusion, antimicrobial activity, and antioxidant effect and stability studies.Results: C-PC showed MIC value of 1.5±0.1 mg/ml and 1.8±0.2 mg/ml against P. acne and S. epidermidis respectively. The developed formulation had a globule diameter of 5.44 mm, pH of 6.8±0.09, the viscosity of 175±0.2cps, spreadability of an 8.6±0.12g. cm/sec and had good consistency. Both formulations were found stable among which, formulation B(FB) had maximum drug content of 95±0.6% and drug release was up to 92±0.8%.Conclusion: The prepared topical C-PC ointment can be successfully employed in the treatment of acneagainstP. acne and S. epidermidis
Double-Logarithmic Two-Loop Self-Energy Corrections to the Lamb Shift
Self-energy corrections involving logarithms of the parameter Zalpha can
often be derived within a simplified approach, avoiding calculational
difficulties typical of the problematic non-logarithmic corrections (as
customary in bound-state quantum electrodynamics, we denote by Z the nuclear
charge number, and by alpha the fine-structure constant). For some logarithmic
corrections, it is sufficient to consider internal properties of the electron
characterized by form factors. We provide a detailed derivation of related
self-energy ``potentials'' that give rise to the logarithmic corrections; these
potentials are local in coordinate space. We focus on the double-logarithmic
two-loop coefficient B_62 for P states and states with higher angular momenta
in hydrogenlike systems. We complement the discussion by a systematic
derivation of B_62 based on nonrelativistic quantum electrodynamics (NRQED). In
particular, we find that an additional double logarithm generated by the
loop-after-loop diagram cancels when the entire gauge-invariant set of two-loop
self-energy diagrams is considered. This double logarithm is not contained in
the effective-potential approach.Comment: 14 pages, 1 figure; references added and typographical errors
corrected; to appear in Phys. Rev.
Ultrasoft NLL Running of the Nonrelativistic O(v) QCD Quark Potential
Using the nonrelativistic effective field theory vNRQCD, we determine the
contribution to the next-to-leading logarithmic (NLL) running of the effective
quark-antiquark potential at order v (1/mk) from diagrams with one potential
and two ultrasoft loops, v being the velocity of the quarks in the c.m. frame.
The results are numerically important and complete the description of ultrasoft
next-to-next-to-leading logarithmic (NNLL) order effects in heavy quark pair
production and annihilation close to threshold.Comment: 25 pages, 7 figures, 3 tables; minor modifications, typos corrected,
references added, footnote adde
Resolving the Large-N Nuclear Potential Puzzle
The large nuclear potential puzzle arose because three- and
higher-meson exchange contributions to the nucleon-nucleon potential did not
automatically yield cancellations that make these contributions consistent with
the general large scaling rules for the potential. Here it is proposed
that the resolution to this puzzle is that the scaling rules only apply for
energy-independent potentials while all of the cases with apparent
inconsistencies were for energy-dependent potentials. It is shown explicitly
how energy-dependent potentials can have radically different large N behavior
than an equivalent energy-independent one. One class of three-meson graphs is
computed in which the contribution to the energy-independent potential is
consistent with the general large N rules even though the energy-dependent
potential is not.Comment: Corrections to the toy mode
FORMULATION AND DEVELOPMENT OF LENALIDOMIDE LOADED DELAYED RELEASE MINI TABLETS IN CAPSULES
Objective: Formulation and development of delayed release mini tablets in the capsule of drug lenalidomidein terms of dissolution and stability was the objective of the present work.Methods: Tablets of less than or equal to 3 millimetres diameter are Mini-tablets, which were filled into a capsule. Direct compression method using multi-tip punch was used for compression and coated with eudragit L100 as a seal coating material and with eudragit L30D55 as an enteric coating material was done. Different formulations were prepared and subjected for evaluation like weight variation, hardness, friability, disintegration, and dissolution studies. The optimized formulation was compared to marketed product based on drug released profile and also subjected for stability studies.Results: The results revealed that the in vitro drug release of prepared formulations, F1, F2, F3, and F4 was subjected for acid resistance test for 2 h in 0.1N HCl and has a comparable dissolution profile in phosphate buffer of 6.8 pH. FormulationF4 was subjected for stability studies and no significant difference was observed in 3 mo 40 °C/75% RH accelerated stability condition.Conclusion: The dissolution profile of formulation F4 was found better than that of market product. Based on evaluation results, the study concluded that F4formulationwas considered as an optimized formulation.Â
PREPARATION AND EVALUATION OF SIMVASTATIN TRANSDERMAL FILM
Objective: The objective of the study was to prepare simvastatin transdermal films for the treatment of atherosclerosis and to evaluate the effect of concentration of polymer on penetration enhancement.
Methods: Solvent evaporation technique was employed for the preparation of films and the prepared films were evaluated for various physicochemical properties of films such as tensile strength, thickness, surface pH, swellability, drug content, moisture content and folding endurance. In vitro drug, release study and release kinetics were also studied.
Results: Tensile strength ranged from 3.56±0.343 to 4.56±0.12 (N/mm²). The films were of uniform weight. Thickness varied from 0.2±0.3 mm to 0.2±0.8 mm. Surface pH ranged from 6.6±0.14 to 6.9±0.16. Percentage swellability ranged from12.1±0.36 to 16.3±0.22. Percentage drug content ranged from 88.4±0.7% to 90.5±0.6% in all the formulation. Percentage moisture content ranged from 0.864 to 1.03%. Moisture uptake was from 2.6±0.24 to 2.9±0.072. The folding endurance test gave satisfactory results and F3 formulation showed maximum drug release.
Conclusion: From the study, it was concluded that out of various formulations, the F3 formulation was found to be the optimum formulation with 88% drug release at the fourteenth hour
Deciphering top flavor violation at the LHC with B factories
The LHC will have unprecedented sensitivity to flavor-changing neutral
current (FCNC) top quark decays, whose observation would be a clear sign of
physics beyond the standard model. Although many details of top flavor
violation are model dependent, the standard model gauge symmetries relate top
FCNCs to other processes, which are strongly constrained by existing data. We
study these constraints in a model independent way, using a low energy
effective theory from which the new physics is integrated out. We consider the
most important operators which contribute to top FCNCs and analyze the current
constraints on them. We find that the data rule out top FCNCs at a level
observable at the LHC due to most of the operators comprising left-handed first
or second generation quark fields, while there remains a substantial window for
top decays mediated by operators with right-handed charm or up quarks. If FCNC
top decays are observed at the LHC, such an analysis may help decipher the
underlying physics.Comment: 17 pages, 5 figures; some typos correcte
The 678Â Hz acoustic immittance probe tone: a more definitive indicator of PET than the traditional 226Â Hz method.
BACKGROUND: The accurate diagnosis of Eustachian tube (ET) dysfunction can be very difficult. Our aim is to determine whether a 678 Hz probe tone is a more accurate indicator of Patulous ET (PET) than the 226 Hz probe tone when used in compliance over time (COT) testing. METHODS: Twenty subjects (11 normal ET ears and 7 PET ears) were individually seated in an examination room and connected to a GSI TympStar Middle Ear Analyzer. The order of probe tone frequency (678 or 226 Hz) was randomized. Baseline "testing" COT recordings for each ear undergoing testing were completed. Subjects were instructed to occlude their contralateral nostril and to breathe forcefully in and out through their ipsilateral nostril until the test had run to completion. This process was repeated with the probe tone that had not been previously run. For the control group, each subject had one random ear tested. For the experimental group, only the affected ear(s) was tested. Wilcoxon rank rum tests were performed to determine statistical significance. RESULTS: The baseline COT measurements for the control group and PET group were similar, 0.86 mL (SD = 0.34) and 0.74 (SD = 0.33) respectively. Comparing the 226 Hz tone between groups revealed that PET patients had a median COT difference 0.19 mL higher than healthy ET patients, and for the 678 Hz tone, PET patients had a median COT difference of 0.57 mL higher than healthy ET patients. Both were deemed to be statistically significant (p = 0.002, p = 0.004 respectively). The was a statistically significant median COT difference between the 678 Hz and 226 Hz of 0.61 mL (p = 0.034) for the PET group, while the same comparison for the control group of 0.05 mL was not significant (p = 0.262), suggesting that the 678 Hz tone yields a larger response for PET than the 226 Hz tone, and no difference for the control group, thus making it less prone to artifact noise interference. CONCLUSION: The 678 Hz probe tone is a more reliable indicator of ET patency, and should be preferably used over the 226 Hz tone for future COT testing
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