429 research outputs found
p53 Mutation in Squamous Cell Carcinomas from Psoriasis Patients Treated with Psoralen + UVA (PUVA)
Individuals suffering from psoriasis are treated with a combination of psoralen and UVA radiation, commonly referred to as "PUVA" therapy. Epidemiologic studies have shown that PUVA therapy is a risk factor for skin cancer in psoriasis patients. Although PUVA treatment induces skin cancer in laboratory animals, it is unknown whether the increased incidence of skin cancer reported in PUVA-treated psoriasis patients is due to the carcinogenic effects of PUVA or due to other factors such as UVB. Because CV and PUVA induce different types of DNA damage resulting in unique types of p53 mutation, we investigated whether skin cancers from PUVA-treated psoriasis patients have PUVA-type or UV-type p53 mutations. Analysis of 17 squamous cell carcinomas (SCCs) from Austrian PUVA-treated patients revealed a total of 25 p53 mutations in 11 SCCs. A majority of p53 mutations occurred at 5'TpG sites. Although previous studies have shown that 5'TpA sites are the primary targets for PUVA mutagenesis, substitutions at 5'TpG sites are also quite common. Interestingly, a sizable portion of p53 mutations detected were C→T or CC→TT transitions, characteristic of UV-induced mutations. Because some psoriasis patients had substantial exposure to UVB before PUVA therapy and because the light sources used in PUVA therapy contained small but significant wave-lengths in the UVB region, it is possible that the C→T and CC→TT transitions detected in SCCs from PUVA-treated patients were induced by UVB. Nonetheless, our results indicate that both PUVA and UVB may play a role in the development of skin cancer in Austrian psoriasis patients who undergo PUVA therapy
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Model predictive control of a CSTR: A comparative study among linear and nonlinear model approaches
© 2017 IEEE. This paper presents a comparative study of two widely accepted model predictive control schemes based on mixed logical dynamical (MLD) and nonlinear modeling approaches with application to a continuous stirred tank reactor (CSTR) system. Specifically, we approximate the nonlinear behavior of a CSTR system with multiple local linear models in a MLD framework. The main benefit of such a scheme is the significant improvement in model accuracy when compared with a single linearized model. The benefits and trade-offs associated with predictive control laws synthesized using MLD and nonlinear modeling approaches are also compared.National Research Foundation, Singapore
Rotating compact star with superconducting quark matter
A compact star with superconducting quark core, the hadron crust and the
mixed phase between the two is considered. The quark meson coupling model for
hadron matter and the color flavor locked quark model for quark matter is used
in order to construct the equation of state for the compact star. The effect of
pairing of quarks in the color flavor locked phase and the mixed phase on the
mass, radius, and period of the rotating star is studied.Comment: 11 pages, 5 figure
Modified Newton-Raphson Method to Tune Feedback Gains of Control System for Standing by Functional Neuromuscular Stimulation Following Spinal Cord Injury
Background: Functional neuromuscular stimulation (FNS) can restore standing capabilities following spinal cord injury.
Feedback control of these systems can optimize performance by reducing the required upper extremity support. However, tuning
these control systems can be intensive and clinically inconvenient
Effect of altitude on volatile organic and phenolic compounds of Artemisia brevifolia Wall ex Dc. from the Western Himalayas
Evaluation of Annual Statice (Limonium sinuatum L.) Cultivars
A field study was conducted during rabi season of 2003-2004 to evaluate the potential of statice cultivars as cut flower crop in the field of Department of Floriculture and Landscape Gardening, K.R.C. College of Horticulture, Arabhavi. The experiment was laid out as a Randomised Block Design with four replications. The panicles of each variety were harvested when calycys of individual flower have mostly opened and showing colour. The cultivar Turbo White recorded maximum plant height (21.78 cm), panicle length (80.94 cm), stem diameter (0.61 cm), no. of leaves (186.60), maximum fresh weight of panicles (530.09 g/plant), plant spread 62.15 cm2 and remained superior over others. The results are in agreement with the findings of Angadi (2000) in China aster. Maximum panicle production per plant (25.64) was recorded in cv. Turbo White, which was on par with the cultivar Turbo Carmine (22.54). The results were in line with the findings of Kumar et al. (1998) in annual statice Turbo White. The cultivar Turbo White was good in quality parameters by recording maximum panicle length, girth and number of branches per panicle. It was also vigorous in vegetative growth. Therefore, the cultivar could produce better quality panicles and found to be suitable for semi arid regions
The electron electric dipole moment enhancement factors of Rubidium and Caesium atoms
The enhancement factors of the electric dipole moment (EDM) of the ground
states of two paramagnetic atoms; rubidium (Rb) and caesium (Cs) which are
sensitive to the electron EDM are computed using the relativistic
coupled-cluster theory and our results are compared with the available
calculations and measurements. The possibility of improving the limit for the
electron EDM using the results of our present work is pointed out.Comment: AISAMP7 Conference paper, Accepted in Journal of Physics: Conference
Series: 200
Theoretical determination of lifetimes of metastable states in Sc III and Y III
Lifetimes of the first two metastable states in Sc^{2+} and Y^{2+} are
determined using the relativistic coupled-cluster theory. There is a
considerable interest in studying the electron correlation effects in these
ions as though their electronic configurations are similar to the neutral
alkali atoms, their structures are very different from the latter. We have made
a comparative study of the correlation trends between the above doubly ionized
systems with their corresponding neutral and singly ionized iso-electronic
systems. The lifetimes of the excited states of these ions are very important
in the field of astrophysics, especially for the study of post-main sequence
evolution of the cool giant stars.Comment: 13 pages, 1 figure and 5 table
Exploring Biorthonormal Transformations of Pair-Correlation Functions in Atomic Structure Variational Calculations
Multiconfiguration expansions frequently target valence correlation and
correlation between valence electrons and the outermost core electrons.
Correlation within the core is often neglected. A large orbital basis is needed
to saturate both the valence and core-valence correlation effects. This in turn
leads to huge numbers of CSFs, many of which are unimportant. To avoid the
problems inherent to the use of a single common orthonormal orbital basis for
all correlation effects in the MCHF method, we propose to optimize independent
MCHF pair-correlation functions (PCFs), bringing their own orthonormal
one-electron basis. Each PCF is generated by allowing single- and double-
excitations from a multireference (MR) function. This computational scheme has
the advantage of using targeted and optimally localized orbital sets for each
PCF. These pair-correlation functions are coupled together and with each
component of the MR space through a low dimension generalized eigenvalue
problem. Nonorthogonal orbital sets being involved, the interaction and overlap
matrices are built using biorthonormal transformation of the coupled basis sets
followed by a counter-transformation of the PCF expansions.
Applied to the ground state of beryllium, the new method gives total energies
that are lower than the ones from traditional CAS-MCHF calculations using large
orbital active sets. It is fair to say that we now have the possibility to
account for, in a balanced way, correlation deep down in the atomic core in
variational calculations
Relativistic calculations of the lifetimes and hyperfine structure constants in Zn
This work presents accurate {\it ab initio} determination of the magnetic
dipole (M1) and electric quadrupole (E2) hyperfine structure constants for the
ground and a few low-lying excited states in Zn, which is one of
the interesting systems in fundamental physics. The coupled-cluster (CC) theory
within the relativistic framework has been used here in this calculations. Long
standing demands for a relativistic and highly correlated calculations like CC
can be able to resolve the disagreements among the lifetime estimations
reported previously for a few low-lying states of Zn. The role of
different electron correlation effects in the determination of these quantities
are discussed and their contributions are presented.Comment: 9 pages, 1 figure. submitted to J. Phys. B Fast Trac
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