1,434 research outputs found
Relationship between Electronic and Geometric Structures of the O/Cu(001) System
The electronic structure of the
O/Cu(001) system has been calculated using locally self-consistent, real space
multiple scattering technique based on first principles. Oxygen atoms are found
to perturb differentially the long-range Madelung potentials, and hence the
local electronic subbands at neighboring Cu sites. As a result the
hybridization of the oxygen electronic states with those of its neighbors leads
to bonding of varying ionic and covalent mix. Comparison of results with those
for the c(2x2) overlayer shows that the perturbation is much stronger and the
Coulomb lattice energy much higher for it than for the
phase. The main driving force for the
0.5ML oxygen surface structure formation on Cu(001) is thus the long-range
Coulomb interaction which also controls the charge transfer and chemical
binding in the system.Comment: 17 pages, 8 figure
Classical and quantum geometrodynamics of 2d vacuum dilatonic black holes
We perform a canonical analysis of the system of 2d vacuum dilatonic black
holes. Our basic variables are closely tied to the spacetime geometry and we do
not make the field redefinitions which have been made by other authors. We
present a careful discssion of asymptotics in this canonical formalism.
Canonical transformations are made to variables which (on shell) have a clear
spacetime significance. We are able to deduce the location of the horizon on
the spatial slice (on shell) from the vanishing of a combination of canonical
data. The constraints dramatically simplify in terms of the new canonical
variables and quantization is easy. The physical interpretation of the variable
conjugate to the ADM mass is clarified. This work closely parallels that done
by Kucha{\v r} for the vacuum Schwarzschild black holes and is a starting point
for a similar analysis, now in progress, for the case of a massless scalar
field conformally coupled to a 2d dilatonic black hole.Comment: 21 pages, latex fil
Doping induced inhomogeneity in high-Tc superconductors
Doping and disorder are inseparable in the superconducting cuprates. Assuming
the simplest possible disordered doping, we construct a semiphenomenological
model and analyze its experimental consequences. Among the affected
experimental quantities are the ARPES spectra and thermodynamic properties.
From our model we make a prediction for the width of the local
superconducting gap distribution with the only experimentally unknown parameter
being the superconducting correlation length. Thus, our model provides a direct
way of determining the superconducting correlation length from a known
experimental gap distribution.Comment: 5 pages, 3 eps figures. Expanded version of talk presented by AVB at
the ISS 2000, Oct 14-16, Tokyo, Japa
PRODUCTION OF BETALAINS FROM HAIRY ROOT CULTURE OF BETA VULGARIS AND ITS USE IN PARACETAMOL SYRUP AS A NATURAL COLOURANT
Objective: The present study was aimed to extract betalains from hairy root culture of Beta vulgaris and its use in pharmaceutical formulations as a colorant.
Methods: Hairy roots were initiated using different strains of Agrobacterium rhizogenes such as A.2/83, A.20/83, A.4, and LMG 150; LMG 150 was found to initiate a large number of hairy roots, and betalain content was estimated. Paracetamol syrup was prepared using extracted betalains as a colorant at different concentrations of 10 and 30 mg/150 ml. Stability studies were carried out at a different temperatures such as 25°C, 30°C, and 40°C) and light (dark, 1000 and 2000 lux) for 45 days.
Results: In case of a concentration of 10 mg/150 ml syrup, the effects of temperature such as 25°C, 30°C, and 40°C and dark condition on the degradation of betalains were found to be 48%, 88%, and 100% in 45 days, respectively. The effects of temperature such as 25°C, 30°C, and 40°C at light 1000 lux on degradations of betalains were found to be 81% and 98% at 25°C and 30°C in 45 days, respectively, and 100% at 40°C in 30 days and at 2000 lux were found to be 100% at 25°C and 30°C in 30 days and 100% at 40°C in 10 days. The similar levels of degradation rate were observed with a concentration of 30 mg/150 ml.
Conclusion: Experimental data demonstrated that formulation with betalains exhibited better stability at the dark condition and lower temperature
Dirac Quantization of Parametrized Field Theory
Parametrized field theory (PFT) is free field theory on flat spacetime in a
diffeomorphism invariant disguise. It describes field evolution on arbitrary
foliations of the flat spacetime instead of only the usual flat ones, by
treating the `embedding variables' which describe the foliation as dynamical
variables to be varied in the action in addition to the scalar field. A formal
Dirac quantization turns the constraints of PFT into functional Schrodinger
equations which describe evolution of quantum states from an arbitrary Cauchy
slice to an infinitesimally nearby one.This formal Schrodinger picture- based
quantization is unitarily equivalent to the standard Heisenberg picture based
Fock quantization of the free scalar field if scalar field evolution along
arbitrary foliations is unitarily implemented on the Fock space. Torre and
Varadarajan (TV) showed that for generic foliations emanating from a flat
initial slice in spacetimes of dimension greater than 2, evolution is not
unitarily implemented, thus implying an obstruction to Dirac quantization.
We construct a Dirac quantization of PFT,unitarily equivalent to the standard
Fock quantization, using techniques from Loop Quantum Gravity (LQG) which are
powerful enough to super-cede the no- go implications of the TV results. The
key features of our quantization include an LQG type representation for the
embedding variables, embedding dependent Fock spaces for the scalar field, an
anomaly free representation of (a generalization of) the finite transformations
generated by the constraints and group averaging techniques. The difference
between 2 and higher dimensions is that in the latter, only finite gauge
transformations are defined in the quantum theory, not the infinitesimal ones.Comment: 33 page
2008 Abstracts Collection -- IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science
This volume contains the proceedings of the 28th international conference on the Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2008), organized under the auspices of the Indian Association for Research in Computing Science (IARCS)
PHARMACOLOGICAL AND ANTI CANCER ACTIVITY OF Ipomoea sepiaria METHANOLIC EXTRACT AGAINST PC-3 CELL LINE
A few conventional restorative plants contain in explored concerning their enemy of corpulence likely wellsprings of is Ipomoea sepiaria Koenig ex. Roxb. The medicine is supposed in tales game plan of prescription for various accommodating properties like, love elixir and arsenic hurting, tonic, re-establishing, diuretic, laxative, uterotonic and sterility in women and leaves is shown particularly in diabetes. Phytochemical screening of different concentrates of Ipomoea sepiaria exposed the presence and non-attendance of various phytochemicals are available in ethanol remove, further examinations were done with leaves of Ipomoea sepiaria ethanol separate. PC3 (PC-3) is a human prostate malignancy cell lines that are profoundly utilized in examining the biochemical changes prostatic disease cells. Explores on PC-3 human prostate malignancy cell lines control are required in the current many years. The anticancer action of fluid concentrate of Ipomoea sepiaria was researched by 3-(4,5-dimethylthiazol-2-yl)- 2, 5-diphenyltetrazolium (MTT) measure utilizing PC-3 cell line. The current experimentation was indicated that watery concentrate of Ipomoea sepiaria, when exposed to various focuses on PC-3 cells demonstrated IC50 cell hindrance at about 5μM for 48 hours and about 2 μM for 72 hours. The information made by this particular examination gives relevant pharmacognostic and phytochemical data needed for proper distinctive confirmation and check of leaves of this particular species.
 
PHYTOCHEMICAL SCREENING AND COMPARATIVE GC–MS ANALYSIS OF BIOACTIVE COMPOUNDS PRESENT IN METHANOLIC LEAF AND LATEX EXTRACT Calotropis gigantea (L)
Medicinal plants are considered as important source of promising bioactive compounds. Calotropis gigantea is a traditional medicinal plant which is known to have biochemical constituents with potential medicinal properties. Qualitative analysis showed the presence of alkaloids, terpenoids, saponins, tannins and cardiac glycosides and absence of flavonoids in ethanolic extract of C. gigantea, while the chloroform leaf extract showed absence of flavonoids and cardiac glycosides. Bioactive compounds since leaf and latex of C. gigantea utilized GC-MS and activity investigation. The GC-MS investigation uncovered the presence of complete 46 bioactive mixes (24 from leaves and 22 from latex) with significant movement. The majority of the mixes were discovered to be comparable in both leaf and latex, however little variety was likewise seen in their synthetic profile. The concoction mixes saw in just latex were 1-[(T-butyl) dimethyl silyl thin] butane, 1-Hexadecyne, Hexadecane, L-Glutamic corrosive, Phenol-3-isoproxy-5-methyl, Trocosane and Z-1,6-Tridecadiene. Mixes distinguished uniquely from the leaves were Azulene, Benalaxyl, Cis-vaccenic corrosive, Levomenol, Profenofos, β-Tocopherol and β-Sitosterol, while the remainder of the mixes were comparable in both leaf and latex. Major of bioactive compounds presents Gas Chromatography-Mass Spectroscopy (GC-MS) analysis. C. gigantea is a perennial plant abundantly found in all parts of the country (India) and wild in nature. The leaves of the plant were found to contain various primary and secondary metabolites
Oral Health Status of Children with Cardiac Disease and the Awareness, Attitude and Knowledge of their Parents.
The prevention of oral disease is the most desirable way of ensuring
good dental health for children with cardiac disease. Oral cavity is a natural
source of many microorganism and alteration in oral health leads to changes in
the eco system where some of the organisms become pathogenic and move
into the blood stream leading to septicaemia. Dental and gingival infections in
patients with cardiac disease may lead to several cardiac complications.
Many situations in which bacteraemia occur, may not be readily identifiable,
and other bacteraemia may occur spontaneously and cannot logically be
prevented. All children at risk should be properly instructed to establish and
maintain best possible oral health to reduce these potential sources of
bacteraemia.
In children with complex heart disease, other associated problems
often appear that may jeopardize dental health. Many of these children have
difficulties with nutrition during the first year of life. Vomiting is a common
problem and to compensate for this they should be fed frequently and night
meals are often necessary to maintain energy intake at an acceptable level. In
addition some of the medicines for heart disease contain sucrose together with
diuretics that can cause xerostomia. Infections often last for longer periods
than in normal children with an increased need for feeding, sometimes at night
when salivary protection is low.
Considering all these aspects, the importance of evaluating the practice
and oral health conditions of children at risk for infective endocarditis was
recognized, as was the need to discover the extent of their parental awareness.9
This study was done to determine the oral health status of children and the
parental knowledge on the importance of oral health in preventing cardiac
complications.
AIMS AND OBJECTIVES:
The aim of this study was
To assess the oral health status of children with cardiac problems.
To determine their parental knowledge, attitude and awareness about
the cardiac disease, importance of maintaining oral health and
importance of infective endocarditis prophylaxis to prevent cardiac
complications
CONCLUSION: It can be concluded :
This study shows that the prevalence of dental caries was high (81.7%)
among the cardiac patients with a mean deft of 3.6 and mean DMFT of
0.76.
The study also showed the untreated component (85% in primary and
98% in mixed dentition) of the caries experience was more than the
treated component (15% in primary and 2% in mixed dentition).
31.33% of children had poor oral hygiene.
The caries experience is relatively high even though the children’s oral
hygiene practices are good. The study showed that 97.3% of children
were tooth brush users, 97.3% were paste users, 93.3% of children
were those who brushed atleast once daily.
Very few parents were aware of the importance of maintaining oral
health (16% ) and importance of infective endocarditis prophylaxis
(7% ) even though most of them were aware of the cardiac problems
of children (87%). Attitude towards dentistry among parents was poor.
84% had never taken their child to a dentist
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