3,636 research outputs found
Time-delayed models of gene regulatory networks
We discuss different mathematical models of gene regulatory networks as relevant to the onset and development of cancer. After discussion of alternativemodelling approaches, we use a paradigmatic two-gene network to focus on the role played by time delays in the dynamics of gene regulatory networks. We contrast the dynamics of the reduced model arising in the limit of fast mRNA dynamics with that of the full model. The review concludes with the discussion of some open problems
Detection of human papillomavirus from liquid-based cytology specimens by in-house PCR: a pilot study
The Papanicolaou smear remains the most common method for the detection of precancerous changes in cervical cytology. However, the introduction of a liquidbased cytology (LBC) technique expands the possibility of cervical intraepithelial neoplasia (CIN) diagnosis, and permits detection of precancerous changes and human papillomavirus (HPV) simultaneously. In the pilot study reported here, using an in-house polymerase chain reaction (PCR) method, high-grade HPV was detected in 32% of a cohort of 38 patients. This conventional PCR method could be developed for use on a real-time PCR platform or in a microtitre-well format and subsequently automated
Pressure sensor using liquid crystals
A pressure sensor includes a liquid crystal positioned between transparent, electrically conductive films (18 and 20), that are biased by a voltage (V) which induces an electric field (E) that causes the liquid crystal to assume a first state of orientation. Application of pressure (P) to a flexible, transparent film (24) causes the conductive film (20) to move closer to or farther from the conductive film (18), thereby causing a change in the electric field (E'(P)) which causes the liquid crystal to assume a second state of orientation. Polarized light (P.sub.1) is directed into the liquid crystal and transmitted or reflected to an analyzer (A or 30). Changes in the state of orientation of the liquid crystal induced by applied pressure (P) result in a different light intensity being detected at the analyzer (A or 30) as a function of the applied pressure (P). In particular embodiments, the liquid crystal is present as droplets (10) in a polymer matrix (12) or in cells (14) in a polymeric or dielectric grid (16) material in the form of a layer (13) between the electrically conductive films (18 and 20). The liquid crystal fills the open wells in the polymer matrix (12) or grid (16) only partially
Critical Properties of Symmetric Nuclear Matter in Low-Density Regime Using Effective-Relativistic Mean Field Formalism
The effective field theory motivated relativistic mean-field (E-RMF)
formalism is employed to study the equation of state (EoS) for the infinite
symmetric nuclear matter at finite temperature using the recently developed
forces FSUGarnet, IOPB-I, G3, and the well known NL3 force parameter. The EoS
is then used to estimate the critical temperature , pressure and
density of the symmetric nuclear matter for the liquid-gas phase
transition. As is not a constrained parameter in both experiments and
theoretical calculations, there is a large uncertainty around its value.
Although, the critical parameters are correlated among themselves. It is
revealed that vector self-coupling of used forces play determining
role in EoS in finite temperature limit. Keeping the incompressibility in
acceptable limit i.e. 240 20 MeV, the lower value of gives a
better result of when compared to the several experimental data. The
critical parameters however show weak correlation with the properties at
saturation density at zero temperature. The compressibility factors calculated
with these parameters are in agreement with the universal value of liquid-gas
systems. Stability conditions are examined along with binodal and spinodal
regions. Besides this, the thermodynamic properties like specific heat and
latent heat are also worked out. We have carried out detailed consistency check
of our calculations using critical exponents and standard scaling laws. All the
exponents are well within the theoretical mean-field results
Properties of hot finite nuclei and associated correlations with infinite nuclear matter
This work aim to study the various thermal characteristics of nuclei in view
of the saturation and critical behavior of infinite nuclear matter. The free
energy of a nucleus is parametrized using the density and temperature-dependent
liquid-drop model and interaction among nucleons is worked out within the
effective relativistic mean-field theory (E-RMF). The effective mass (m,)
and critical temperature of infinite symmetric nuclear matter () of a
given E-RMF parameter force play a seminal role in the estimation of thermal
properties. A larger (m) and of the E-RMF set estimate larger
excitation energy, level density, and limiting temperature for a given
nucleus. The limiting temperature of a nucleus also depends on the behavior of
the nuclear gas surrounding the nucleus, making the equation of state (EoS) at
subsaturation densities an important input. A stiff EoS in the subsaturation
region estimates a higher pressure of the nuclear gas making it less stable.
Since the plays an important part in these calculations, we perform a
Pearson correlation statistical study of fifteen E-RMF parameter sets,
satisfying the relevant constraint on EoS. Effective mass seems to govern the
thermal characteristics of infinite as well as finite nuclear matter in the
framework of E-RMF theory.Comment: 13 pages, 9 figure
Thermal effects in hot and dilute homogeneous asymmetric nuclear matter
We present a comprehensive analysis of hot and dilute isospin-asymmetric
nuclear matter employing the temperature-dependent effective-relativistic
mean-field theory (E-RMF). The E-RMF is applied to study the effect of
and meson cross-coupling on the thermal properties of asymmetric
nuclear matter using two recently developed IOPB-I and G3 parameter sets. These
sets are known to reproduce the nuclear matter properties in agreement with
various experimental and observational constraints. We consider the nuclear
matter to be homogeneous and study the equation of state (EoS) for densities,
temperature and asymmetry which are relevant for astrophysical simulations such
as supernovae explosion. The effect of temperature is investigated in reference
to the density-dependent free symmetry energy and its higher-order derivatives
using the well known parabolic approximation. The larger value of
cross-coupling in G3 in addition to the meson
coupling in G3 smoothen the free symmetry energy. Thermal effects on various
state variables are examined at fixed temperature and isospin asymmetry by
separating their T=0 and the finite-T expressions. The thermal effects are
mainly governed by effective mass with larger effective mass estimating larger
thermal contribution. The effect of temperature on isothermal and isentropic
incompressibility is discussed which is in harmony with various available
microscopic calculations. The liquid-gas phase transition properties are
examined in asymmetric matter with two conserved charges in the context of
different slope parameter and comparable symmetry energy in IOPB-I and G3 set.
The spinodal instability, binodal curve and critical properties are found to be
influenced by the slope parameter
Self -extinguishable cellulosic textile from Spinacia oleracea
Flame retardancy has been imparted to cellulosic cotton textiles using spinach (Spinacia Oleracea) juice (SJ). The extracted juice has been made alkaline and then applied a fresh to a bleached and premordanted cotton fabric. The flame retardant properties of both the control and the treated fabrics are analysed for limiting oxygen index (LOI) and vertical flammability. The study shows that the SJ treated fabrics have good flame retardant properties, with LOI of 30 for the SJ treated fabric, showing an increase by about 1.6 times compared to the control fabric with LOI of 18. As a result, the treated fabric does not catch flame and in the vertical flammability test, it burns with an afterglow and a propagation rate of 43.5 mm/min, which is almost 5 times lower than that observed with the control fabric. The mechanism of imparting the flame retardancy to the cotton fabric by application of SJ has been postulated and supported by SEM, EDX and char mechanism studies. The durability of the treatment to soap washing, rubbing, dry-cleaning and sunlight has also been studied. Besides, its application produces a natural green colour on the fabric, and no deterioration in other physical properties is observed
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