760 research outputs found
On a Class of Generalized Elliptic-type Integrals
The aim of this paper is to study a generalized form of elliptic-type integrals
which unify and extend various families of elliptic-type integrals studied
recently by several authors. In a recent communication [1] we
have obtained recurrence relations and asymptotic formula for this generalized
elliptic-type integral. Here we shall obtain some more results which
are single and multiple integral formulae, differentiation formula, fractional
integral and approximations for this class of generalized elliptic-type integrals
DEVELOPMENT OF MESALAZINE MICROSPHERES FOR COLON TARGETING
Objective: The present work was aimed at preparation of mesalazine microspheres by a non-aqueous solvent evaporation method using eudragit S 100 and eudragit L 100 as pH dependent polymers for colon targeting.
Methods: The ratio of drug to polymer was varied and the effect of formulation variables revolutions per minute (RPM) (1000, 1500, 2000 and 2500) and concentration of span 80 (1%, 1.5%, 2% and 2.5%) were studied. Prepared microspheres were evaluated for particle size, percent drug entrapment, granular analysis, in vitro drug release studies, Fourier transformed infrared spectroscopy (FT-IR) Differential Scanning Calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies.
Results: Particle size has decreased and percent drug entrapment had increased with increase in RPM in all formulations. When the span 80 concentration increased, the particle size of the microsphere formulations increased and percent drug entrapment decreased in eudragit S 100 microspheres; whereas in eudragit L 100 microspheres, as the concentration of span 80 increased, the particle size of the microsphere formulations decreased. The prepared microspheres sustained the drug release over a period of 12 h.
Conclusion: Thus eudragit S 100 and eudragit L 100 microspheres could constitute a promising approach for colon-specific and sustained delivery of mesalazine for the treatment of inflammatory bowel disease
Photoaversion in inherited retinal diseases: clinical phenotypes, biological basis, and qualitative and quantitative assessment
Severe light sensitivity is a feature common to a range of ophthalmological and neurological diseases. In
inherited retinal diseases (IRDs) particularly, this may be accompanied by significant visual disruption. These
symptoms are extremely debilitating for affected individuals and have significant implications in terms
of day-to-day activities. Underlying mechanisms remain to be fully elucidated. Currently, there are many
assessments of photoaversion (PA), however, all have limitations, with quantitative measurement in particular needing further evaluation. To understand the complexities associated with photoaversion from
different pathologies, qualitative and quantitative assessments of the light aversion response must be
standardized. There is no treatment to date, and strategies to alleviate symptoms focus on light avoidance.
With respect to IRDs, however, gene therapy is currently being investigated in clinical trials and promising
and further treatments may be on the horizon. The better characterization of these symptoms is an
important end point measure in IRD gene therapy trials
Cake Cutting Algorithms for Piecewise Constant and Piecewise Uniform Valuations
Cake cutting is one of the most fundamental settings in fair division and
mechanism design without money. In this paper, we consider different levels of
three fundamental goals in cake cutting: fairness, Pareto optimality, and
strategyproofness. In particular, we present robust versions of envy-freeness
and proportionality that are not only stronger than their standard
counter-parts but also have less information requirements. We then focus on
cake cutting with piecewise constant valuations and present three desirable
algorithms: CCEA (Controlled Cake Eating Algorithm), MEA (Market Equilibrium
Algorithm) and CSD (Constrained Serial Dictatorship). CCEA is polynomial-time,
robust envy-free, and non-wasteful. It relies on parametric network flows and
recent generalizations of the probabilistic serial algorithm. For the subdomain
of piecewise uniform valuations, we show that it is also group-strategyproof.
Then, we show that there exists an algorithm (MEA) that is polynomial-time,
envy-free, proportional, and Pareto optimal. MEA is based on computing a
market-based equilibrium via a convex program and relies on the results of
Reijnierse and Potters [24] and Devanur et al. [15]. Moreover, we show that MEA
and CCEA are equivalent to mechanism 1 of Chen et. al. [12] for piecewise
uniform valuations. We then present an algorithm CSD and a way to implement it
via randomization that satisfies strategyproofness in expectation, robust
proportionality, and unanimity for piecewise constant valuations. For the case
of two agents, it is robust envy-free, robust proportional, strategyproof, and
polynomial-time. Many of our results extend to more general settings in cake
cutting that allow for variable claims and initial endowments. We also show a
few impossibility results to complement our algorithms.Comment: 39 page
Trafficking activity of myosin XXI is required in assembly of Leishmania flagellum
Actin-based myosin motors have a pivotal role in intracellular trafficking in eukaryotic cells. The parasitic protozoan organism Leishmania expresses a novel class of myosin, myosin XXI (Myo21), which is preferentially localized at the proximal region of the flagellum. However, its function in this organism remains largely unknown. Here, we show that Myo21 interacts with actin, and its expression is dependent of the growth stage. We further reveal that depletion of Myo21 levels results in impairment of the flagellar assembly and intracellular trafficking. These defects are, however, reversed by episomal complementation. Additionally, it is shown that deletion of the Myo21 gene leads to generation of ploidy, suggesting an essential role of Myo21 in survival of Leishmania cells. Together, these results indicate that actin-dependent trafficking activity of Myo21 is essentially required during assembly of the Leishmania flagellum
Classical generalized constant coupling model for geometrically frustrated antiferromagnets
A generalized constant coupling approximation for classical geometrically
frustrated antiferromagnets is presented. Starting from a frustrated unit we
introduce the interactions with the surrounding units in terms of an internal
effective field which is fixed by a self consistency condition. Results for the
magnetic susceptibility and specific heat are compared with Monte Carlo data
for the classical Heisenberg model for the pyrochlore and kagome lattices. The
predictions for the susceptibility are found to be essentially exact, and the
corresponding predictions for the specific heat are found to be in very good
agreement with the Monte Carlo results.Comment: 4 pages, 3 figures, 2 columns. Discussion about the zero T value of
the pyrochlore specific heat correcte
Effect of corrosion on flexural bond strength
Corrosion is one of the main causes affecting durability of structures. Corrosion effects on structures cannot be ignored and replaced. To understand the performance of structures there is a need to study the rate at which different corrosion levels occur. Hence the present investigation has been taken up to study the behaviour of NBS (National Bureau of Standard) beam specimens made up of Ordinary Portland Cement (OPC) and Portland Pozzolona Cement (PPC) concrete matrix were subjected to accelerated corrosion for different corrosion levels of 2.5 % to 10 % at 2.5 % interval. Results are compared with those for control beam specimen. It is observed that bond stress value decreases with the increase in corrosion levels. Also corrosion leads to the decline of load carrying capacity
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