1,047 research outputs found
Electrically neutral Dirac particles in the presence of external fields: exact solutions
In the present article we present exact solutions of the Dirac equation for
electric neutral particles with anomalous electric and magnetic moments. Using
the algebraic method of separation of variables, the Dirac equation is
separated in cartesian, cylindrical and spherical coordinates, and exact
solutions are obtained in terms of special functions.Comment: 20pp, IVIC-CFLE-93/02 (this is a version without Tex problems, the
first version was corrupted
Regularities in Phenotypic Variation as a Property of the Developmental System: Evidence from the Evolution of Early Amphibians
An evident non-randomness in the variability of living organisms is caused by the integrity of their developmental systems, which undergo the evolutionary transformation as a whole. The commonest manifestation of such orderliness is the occurrence of homologous variations in related forms. The evolution of the dominant group of early amphibians (Temnospondyli) provides numerous examples of this phenomenon
IHC characteristics of stem cell markers in PDAC with different degrees of differentiation
Introduction. Cancer stem cells (CSCs) play a key role in the development, progression and metastasis of cancer. Cell surface markers, in particular CD44 and EpCAM, are used to identify CSCs. Marker expression patterns depend on the stage of progression and differentiation. Materials and methods. Histopathological and IHC studies of 49 cases of the pancreas ductal adenocarcinoma (PDAC) of G2, G3 degrees of differentiation. Results of IHC reactions with antibodies against CD44 and EpCAM were estimated by photo digital morphometry and were expressed in immunostained cells relative area (%). Results. Adenocarinoma of the pancreas is characterized by a moderate level of expression of cell surface markers CSC - CD44 and EpCAM. The expression level of CD44 in the І gr. - Me = 34.11% (Q1 = 31.03; Q3 = 38.39), in the II gr. - Me = 43.17% (Q1 = 39.83; Q3 = 47.04), significantly higher than in the I gr. (Kruskal-Wallis test p<0.05). The expression level of EpCAM in the I gr. - Ме=26,10% (Q1=20,42; Q3=31,89), in the II gr. - Ме=31,07% (Q1=27,03; Q3=34,00) (p>0,05). In both groups, the relative area of EpCAM was significantly lower than CD44 (Kruskal-Wallis test p<0.05). Correlation analysis (Pearson's ratio) showed a weak negative relationship between markers at G2 (r = -0.17, p>0.05), at G3 - a weak positive (r = + 0.06, p>0.05)
Quasiparticle band structure based on a generalized Kohn-Sham scheme
We present a comparative full-potential study of generalized Kohn-Sham
schemes (gKS) with explicit focus on their suitability as starting point for
the solution of the quasiparticle equation. We compare quasiparticle
band structures calculated upon LDA, sX, HSE03, PBE0, and HF functionals for
exchange and correlation (XC) for Si, InN and ZnO. Furthermore, the HSE03
functional is studied and compared to the GGA for 15 non-metallic materials for
its use as a starting point in the calculation of quasiparticle excitation
energies. For this case, also the effects of selfconsistency in the
self-energy are analysed. It is shown that the use of a gKS scheme as a
starting point for a perturbative QP correction can improve upon the
deficiencies found for LDA or GGA staring points for compounds with shallow
bands. For these solids, the order of the valence and conduction bands is often
inverted using local or semi-local approximations for XC, which makes
perturbative calculations unreliable. The use of a gKS starting point
allows for the calculation of fairly accurate band gaps even in these difficult
cases, and generally single-shot calculations following calculations
using the HSE03 functional are very close to experiment
Determination of Different Biological Factors on the Base of Dried Blood Spot Technology
It is well-known that distinct biological indices (analytes) have distinct
variability. We try to use some mathematical algorithms to pick out a set of
blood parameters which give an opportunity to retrieve the initial volume of
the blood spotted, and use it to calculate exact concentrations of analyts
interesting to a physician. For our analysis we used the database of
biochemical blood parameters obtained in Russian Scientific Center of
Roentgen-Radiology during 1995-2000, which includes more than 30000 of
patients.Comment: 5 page
Exact solution of the two-dimensional Dirac oscillator
In the present article we have found the complete energy spectrum and the
corresponding eigenfunctions of the Dirac oscillator in two spatial dimensions.
We show that the energy spectrum depends on the spin of the Dirac particle.Comment: revtex, 6pp. IVIC-CFLE 93/0
Structure of 2-Methyl-5,6,7-triphenyl-6,7-dihydropyrazolo[2,3-\u3cem\u3ea\u3c/em\u3e]pyrimidine
C25H21N3, Mr = 363.46, monoclinic, P21/n, a = 9.245 (2), b = 23.502 (5), c = 9.340 (2) Å, β= 103.50(3)°, V=1973.3(2) Å3, Z=4, Dx= 1.220 (2) g cm-3, λ (Mo Kα )= 0.71069 Å, μ = 0.068 cm-1, F(000) = 768, T= 292 K, R = 0.091 for 1442 unique observed reflections. The dihydropyrimidine ring adopts a distorted sofa conformation. The aryl substituents on the saturated C atoms have an axial orientation
Vacuum effects in an asymptotically uniformly accelerated frame with a constant magnetic field
In the present article we solve the Dirac-Pauli and Klein Gordon equations in
an asymptotically uniformly accelerated frame when a constant magnetic field is
present. We compute, via the Bogoliubov coefficients, the density of scalar and
spin 1/2 particles created. We discuss the role played by the magnetic field
and the thermal character of the spectrum.Comment: 17 pages. RevTe
Applications of Pulsed Electromagnetic Fields in Powder Materials High Speed Forming
In current article, applications of electromagnetic pulsed fields for processing of powder
materials are presented. The main attention is paid to the following applications of pulse
electromagnetic fields in powder metallurgy and allied industries: pressing of powders,
manufacturing of powder coatings, and conveying of ferromagnetic powders by means of
pulsed electromagnetic field
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