237 research outputs found
Collectivity, Phase Transitions and Exceptional Points in Open Quantum Systems
Phase transitions in open quantum systems, which are associated with the
formation of collective states of a large width and of trapped states with
rather small widths, are related to exceptional points of the Hamiltonian.
Exceptional points are the singularities of the spectrum and eigenfunctions,
when they are considered as functions of a coupling parameter. In the present
paper this parameter is the coupling strength to the continuum. It is shown
that the positions of the exceptional points (their accumulation point in the
thermodynamical limit) depend on the particular type and energy dependence of
the coupling to the continuum in the same way as the transition point of the
corresponding phase transition.Comment: 22 pages, 4 figure
Pseudo-Hermiticity of an Exactly Solvable Two-Dimensional Model
We study a two-dimensional exactly solvable non-Hermitian non-symmetric
quantum model with real spectrum, which is not amenable to separation of
variables, by supersymmetrical methods. Here we focus attention on the property
of pseudo-Hermiticity, biorthogonal expansion and pseudo-metric operator. To
our knowledge this is the first time that pseudo-Hermiticity is realized
explicitly for a nontrivial two-dimensional case. It is shown that the
Hamiltonian of the model is not diagonalizable.Comment: 14 page
ΠΠ½Π³ΠΈΠ±ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΊΠ°ΡΠΏΠ°Π·Ρ-2 Π² ΠΊΠ»Π΅ΡΠΊΠ°Ρ Π’-ΠΊΠ»Π΅ΡΠΎΡΠ½ΠΎΠΉ Π»ΠΈΠΌΡΠΎΠΌΡ ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ° Jurkat ΠΏΡΠΈ ΠΏΠΎΠΌΠΎΡΠΈ ΠΏΠ΅ΡΠ΅ΠΊΠ»ΡΡΠ°ΡΡΠ΅Π³ΠΎ ΡΠΏΠ»Π°ΠΉΡΠΈΠ½Π³ ΠΎΠ»ΠΈΠ³ΠΎΠ½ΡΠΊΠ»Π΅ΠΎΡΠΈΠ΄Π° ΠΊ Π΅Ρ ΠΏΡΠ΅-ΠΌΠ ΠΠ
Caspase-2 is a key enzyme thinvolved in induction of apoptosis. The caspase-2 level is regulated by alternative splicing (AS) of its mRNA. The aim of this work was to determine the ability of an oligonucleotide complementary to Casp-2 pre-mRNA to induce AS. This oligonucleotide blocked the binding of splicing-regulating proteins to their sites at the end of exon 9 of Casp-2 pre-mRNA, leading to induction of AS of Casp-2 mRNA. The decrease in expression of full-size active splice-variant (Casp-2L) and the increase the expression of a shortened variant (Casp-2S) was demonstrated in human T-cell lymphoma Jurkat cell line. The expression level of total Casp-2 remained unchanged. Disproportion of splice variants of Casp-2 led to inhibition of enzymatic activity of caspase-2.ΠΠ°ΡΠΏΠ°Π·Π°-2 ΡΠ²Π»ΡΠ΅ΡΡΡ ΡΠ΅ΡΠΌΠ΅Π½ΡΠΎΠΌ, ΡΡΠ°ΡΡΠ²ΡΡΡΠΈΠΌ Π² ΠΈΠ½Π΄ΡΠΊΡΠΈΠΈ Π°ΠΏΠΎΠΏΡΠΎΠ·Π°. ΠΠΎΠ»ΠΈΡΠ΅ΡΡΠ²ΠΎ Π°ΠΊΡΠΈΠ²Π½ΠΎΠ³ΠΎ ΡΠ΅ΡΠΌΠ΅Π½ΡΠ° ΠΊΠ°ΡΠΏΠ°Π·Ρ-2 ΡΠ΅Π³ΡΠ»ΠΈΡΡΠ΅ΡΡΡ Π°Π»ΡΡΠ΅ΡΠ½Π°ΡΠΈΠ²Π½ΡΠΌ ΡΠΏΠ»Π°ΠΉΡΠΈΠ½Π³ΠΎΠΌ (ΠΠ‘) Π΅Ρ ΠΌΠ ΠΠ. Π¦Π΅Π»ΡΡ Π΄Π°Π½Π½ΠΎΠΉ ΡΠ°Π±ΠΎΡΡ Π±ΡΠ»ΠΎ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ ΡΠΏΠΎΡΠΎΠ±Π½ΠΎΡΡΠΈ ΠΎΠ»ΠΈΠ³ΠΎΠ½ΡΠΊΠ»Π΅ΠΎΡΠΈΠ΄Π°, ΠΊΠΎΠΌΠΏΠ»Π΅ΠΌΠ΅Π½ΡΠ°ΡΠ½ΠΎΠ³ΠΎ ΠΏΡΠ΅-ΠΌΠ ΠΠ Casp-2, ΠΈΠ½Π΄ΡΡΠΈΡΠΎΠ²Π°ΡΡ ΠΠ‘. ΠΠ°Π½Π½ΡΠΉ ΠΎΠ»ΠΈΠ³ΠΎΠ½ΡΠΊΠ»Π΅ΠΎΡΠΈΠ΄ Π±Π»ΠΎΠΊΠΈΡΠΎΠ²Π°Π» ΡΠ²ΡΠ·ΡΠ²Π°Π½ΠΈΠ΅ ΡΠ΅Π³ΡΠ»ΠΈΡΡΡΡΠΈΡ
ΡΠΏΠ»Π°ΠΉΡΠΈΠ½Π³ Π±Π΅Π»ΠΊΠΎΠ² ΡΠΎ ΡΠ²ΠΎΠΈΠΌΠΈ ΡΠ°ΠΉΡΠ°ΠΌΠΈ Π½Π° ΠΊΠΎΠ½ΡΠ΅ ΡΠΊΠ·ΠΎΠ½Π° 9 ΠΏΡΠ΅-ΠΌΠ ΠΠ Casp-2, ΡΡΠΎ ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΠ»ΠΎ ΠΊ ΠΈΠ½Π΄ΡΠΊΡΠΈΠΈ ΠΠ‘ ΠΌΠ ΠΠ Casp-2: ΠΏΠΎΠ½ΠΈΠΆΠ΅Π½ΠΈΡ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ ΠΏΠΎΠ»Π½ΠΎΡΠ°Π·ΠΌΠ΅ΡΠ½ΠΎΠ³ΠΎ Π°ΠΊΡΠΈΠ²Π½ΠΎΠ³ΠΎ ΡΠΏΠ»Π°ΠΉΡ-Π²Π°ΡΠΈΠ°Π½ΡΠ° Casp-2L ΠΈ ΠΏΠΎΠ²ΡΡΠ΅Π½ΠΈΡ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ ΡΠΊΠΎΡΠΎΡΠ΅Π½Π½ΠΎΠ³ΠΎ Π²Π°ΡΠ°Π½ΡΠ° Casp-2S Π² ΠΊΠ»Π΅ΡΠΊΠ°Ρ
Π’-ΠΊΠ»Π΅ΡΠΎΡΠ½ΠΎΠΉ Π»ΠΈΠΌΡΠΎΠΌΡ ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ° Π»ΠΈΠ½ΠΈΠΈ Jurkat. ΠΡΠΈ ΡΡΠΎΠΌ ΡΡΠΎΠ²Π΅Π½Ρ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ ΠΎΠ±ΡΠ΅ΠΉ Casp-2 Π½Π΅ ΠΈΠ·ΠΌΠ΅Π½ΡΠ»ΡΡ. ΠΠ°ΡΡΡΡΠ΅Π½ΠΈΠ΅ ΠΏΡΠΎΠΏΠΎΡΡΠΈΠΈ ΡΠΏΠ»Π°ΠΉΡ-Π²Π°ΡΠΈΠ°Π½ΡΠΎΠ² Casp-2 ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΠ» ΠΊ ΠΈΠ½Π³ΠΈΠ±ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΡΠ΅ΡΠΌΠ΅Π½ΡΠ°ΡΠΈΠ²Π½ΠΎΠΉ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΊΠ°ΡΠΏΠ°Π·Ρ-2
Hamiltonian systems of hydrodynamic type in 2 + 1 dimensions
We investigate multi-dimensional Hamiltonian systems associated with constant
Poisson brackets of hydrodynamic type. A complete list of two- and
three-component integrable Hamiltonians is obtained. All our examples possess
dispersionless Lax pairs and an infinity of hydrodynamic reductions.Comment: 34 page
Highly reflective Ru Y multilayer mirrors for the spectral range of 9 11 nm
The results of the investigation of the reflective characteristics of multilayer mirrors based on Ru Y are presented. Reflection coefficients at the level of 38.5 at an operating wavelength of 9.4 nm. It is shown that the deposition of B4C barrier layers onto Y layers makes it possible to significantly increase the reflection coefficient compared to structures without barrier layers. A reflectance of 54 was obtained for mirrors optimized for 11.4 nm, which is close to the theoretical limit for these material
A toy model of fractal glioma development under RF electric field treatment
A toy model for glioma treatment by a radio frequency electric field is
suggested. This low-intensity, intermediate-frequency alternating electric
field is known as the tumor-treating-field (TTF). In the framework of this
model the efficiency of this TTF is estimated, and the interplay between the
TTF and the migration-proliferation dichotomy of cancer cells is considered.
The model is based on a modification of a comb model for cancer cells, where
the migration-proliferation dichotomy becomes naturally apparent. Considering
glioma cancer as a fractal dielectric composite of cancer cells and normal
tissue cells, a new effective mechanism of glioma treatment is suggested in the
form of a giant enhancement of the TTF. This leads to the irreversible
electroporation that may be an effective non-invasive method of treating brain
cancer.Comment: Submitted for publication in European Physical Journal
Quantum deformation of the angular distributions of synchrotron radiation. Emission of particles in the first excited state
The exact expressions for the characteristics of synchrotron radiation of
charged particles in the first excited state are obtained in analytical form
using quantum theory methods. We performed a detailed analysis of the angular
distribution structure of radiation power and its polarization for particles
with spin 0 and 1/2. It is shown that the exact quantum calculations lead to
results that differ substantially from the predictions of classical theory
Π€ΠΈΠ·ΠΈΠΊΠΎ-Ρ ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ²ΠΎΠΉΡΡΠ²Π° ΠΌΡΡΠ°Π½ΡΠ½ΡΡ ΡΠΎΡΠΌ L-Π°ΡΠΏΠ°ΡΠ°Π³ΠΈΠ½Π°Π·Ρ ΠΈΠ· Rhodospirillum rubrum, ΠΎΠ±Π»Π°Π΄Π°ΡΡΠΈΡ Π°Π½ΡΠΈΡΠ΅Π»ΠΎΠΌΠ΅ΡΠ°Π·Π½ΠΎΠΉ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡΡ
Rru_A3730 protein is a bacterial Rhodospirillum rubrum L-asparaginase (RrA), which is known by its anticancer activity. RrA variants with point amino acid substitutions in the region of 150 amino acids residues: RrA17N, K149E, RrAE149R, V150P, F151T, RrΠ17N, E149R, V150P, RrAE149R, V150P, showed antiproliferative properties, and also by their ability to suppress telomerase activity. This work is devoted to comparison of physical-chemical and catalytic properties of these mutant forms of RrA. It is shown that pH optimum is in the alkaline zone (8.5 β 9.3); L-glutaminase and D-asparaginase activity is respectively not more than 0.1% and 1.6% of L-asparaginase for all studied variants of RrA. The presence of the N17-terminal amino acid sequence MASMTGGQMGRGSSRQ of the capsid protein of bacteriophage T7 in the RrA structure leads to an increase in the thermal stability of mutant RrA analogues (from 50Β°C to 56Β°C) and their resistance to denaturation in the presence of 3 β 4 M urea. It is of Metal ions exhibit multidirectional effects on L-asparaginase activity of RrA. K+, Ca2+, Zn2+, Cs+, Co2+ in significantly affect the activity of L-asparaginase, while Mn2+, Cu2+, Fe3+ ions inhibit it. There was no correlation between antitelomerase (antiproliferative) activity and kinetic properties of mutant forms of L-asparaginase RrA.ΠΠ΅Π»ΠΎΠΊ Rru_A3730, ΠΈΠ·Π²Π΅ΡΡΠ½ΡΠΉ ΠΊΠ°ΠΊ Π±Π°ΠΊΡΠ΅ΡΠΈΠ°Π»ΡΠ½Π°Ρ L-Π°ΡΠΏΠ°ΡΠ°Π³ΠΈΠ½Π°Π·Π° Rhodospirillum rubrum, ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»ΡΠ΅Ρ ΠΈΠ½ΡΠ΅ΡΠ΅Ρ Π² ΠΊΠ°ΡΠ΅ΡΡΠ²Π΅ ΠΏΠΎΡΠ΅Π½ΡΠΈΠ°Π»ΡΠ½ΠΎΠ³ΠΎ ΠΏΡΠΎΡΠΈΠ²ΠΎΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΠΎΠ³ΠΎ ΡΡΠ΅Π΄ΡΡΠ²Π°, ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎ Π΅Ρ Π²Π°ΡΠΈΠ°Π½ΡΡ Ρ ΡΠΎΡΠ΅ΡΠ½ΡΠΌΠΈ Π°ΠΌΠΈΠ½ΠΎΠΊΠΈΡΠ»ΠΎΡΠ½ΡΠΌΠΈ Π·Π°ΠΌΠ΅Π½Π°ΠΌΠΈ Π² ΡΠ°ΠΉΠΎΠ½Π΅ 150 Π°ΠΌΠΈΠ½ΠΎΠΊΠΈΡΠ»ΠΎΡΠ½ΠΎΠ³ΠΎ ΠΎΡΡΠ°ΡΠΊΠ° (Π°.ΠΊ.ΠΎ.): RrA17N, K149E, RrAE149R, V150P, F151T, RrΠ17N, E149R, V150P, RrAE149R, V150P, ΠΎΠ±Π»Π°Π΄Π°ΡΡΠΈΠ΅ Π½Π΅ ΡΠΎΠ»ΡΠΊΠΎ Π°Π½ΡΠΈΠΏΡΠΎΠ»ΠΈΡΠ΅ΡΠ°ΡΠΈΠ²Π½ΡΠΌΠΈ ΡΠ²ΠΎΠΉΡΡΠ²Π°ΠΌΠΈ, Π½ΠΎ ΠΈ ΡΠΏΠΎΡΠΎΠ±Π½ΠΎΡΡΡΡ ΠΏΠΎΠ΄Π°Π²Π»ΡΡΡ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ ΡΠ΅Π»ΠΎΠΌΠ΅ΡΠ°Π·Ρ. ΠΠ°Π½Π½Π°Ρ ΡΠ°Π±ΠΎΡΠ° ΠΏΠΎΡΠ²ΡΡΠ΅Π½Π° ΡΡΠ°Π²Π½Π΅Π½ΠΈΡ ΡΠΈΠ·ΠΈΠΊΠΎ-Ρ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΈ ΠΊΠ°ΡΠ°Π»ΠΈΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ²ΠΎΠΉΡΡΠ² ΡΡΠΈΡ
ΠΌΡΡΠ°Π½ΡΠ½ΡΡ
ΡΠΎΡΠΌ RrA. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ Π΄Π»Ρ Π²ΡΠ΅Ρ
ΠΈΠ·ΡΡΠ΅Π½Π½ΡΡ
Π²Π°ΡΠΈΠ°Π½ΡΠΎΠ² RrA ΡΠ ΠΎΠΏΡΠΈΠΌΡΠΌ Π½Π°Ρ
ΠΎΠ΄ΠΈΡΡΡ Π² ΡΠ΅Π»ΠΎΡΠ½ΠΎΠΉ Π·ΠΎΠ½Π΅ (8.5 β 9.3); L-Π³Π»ΡΡΠ°ΠΌΠΈΠ½Π°Π·Π½Π°Ρ ΠΈ D-Π°ΡΠΏΠ°ΡΠ°Π³ΠΈΠ½Π°Π·Π½Π°Ρ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ ΡΠΎΡΡΠ°Π²Π»ΡΡΡ, ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²Π΅Π½Π½ΠΎ, Π½Π΅ Π±ΠΎΠ»Π΅Π΅ 0.1% ΠΈ 1.6% ΠΎΡ L-Π°ΡΠΏΠ°ΡΠ°Π³ΠΈΠ½Π°Π·Π½ΠΎΠΉ. ΠΡΠΈΡΡΡΡΡΠ²ΠΈΠ΅ 17N-ΠΊΠΎΠ½ΡΠ΅Π²ΠΎΠΉ Π°ΠΌΠΈΠ½ΠΎΠΊΠΈΡΠ»ΠΎΡΠ½ΠΎΠΉ ΠΏΠΎΡΠ»Π΅Π΄ΠΎΠ²Π°ΡΠ΅Π»ΡΠ½ΠΎΡΡΠΈ MASMTGGQQMGRGSSRQ ΠΊΠ°ΠΏΡΠΈΠ΄Π½ΠΎΠ³ΠΎ Π±Π΅Π»ΠΊΠ° Π±Π°ΠΊΡΠ΅ΡΠΈΠΎΡΠ°Π³Π° Π’7 Π² ΡΡΡΡΠΊΡΡΡΠ΅ RrA ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΡ ΠΊ ΠΏΠΎΠ²ΡΡΠ΅Π½ΠΈΡ ΡΠ΅ΡΠΌΠΎΡΡΠ°Π±ΠΈΠ»ΡΠ½ΠΎΡΡΠΈ ΠΌΡΡΠ°Π½ΡΠ½ΡΡ
Π°Π½Π°Π»ΠΎΠ³ΠΎΠ² RrA (ΠΎΡ 50Β°Π‘ Π΄ΠΎ 56Β°Π‘) ΠΈ ΠΈΡ
ΡΡΡΠΎΠΉΡΠΈΠ²ΠΎΡΡΠΈ ΠΊ Π΄Π΅Π½Π°ΡΡΡΠ°ΡΠΈΠΈ Π² ΠΏΡΠΈΡΡΡΡΡΠ²ΠΈΠΈ 3 β 4 Π ΠΌΠΎΡΠ΅Π²ΠΈΠ½Ρ. ΠΡΡΠ²Π»Π΅Π½ ΡΠ°Π·Π½ΠΎΠ½Π°ΠΏΡΠ°Π²Π»Π΅Π½Π½ΡΠΉ ΡΡΡΠ΅ΠΊΡ ΠΈΠΎΠ½ΠΎΠ² ΠΌΠ΅ΡΠ°Π»Π»ΠΎΠ² Π½Π° L-Π°ΡΠΏΠ°ΡΠ°Π³ΠΈΠ½Π°Π·Π½ΡΡ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ Π²Π°ΡΠΈΠ°Π½ΡΠΎΠ² RrA: ΠΈΠΎΠ½Ρ K+, Ca2+, Zn2+, Cs+, Co2+ ΡΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎ Π½Π΅ Π²Π»ΠΈΡΡΡ Π½Π° Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ L-Π°ΡΠΏΠ°ΡΠ°Π³ΠΈΠ½Π°Π·Ρ, Π΄ΠΎΠ±Π°Π²Π»Π΅Π½ΠΈΠ΅ ΠΈΠΎΠ½ΠΎΠ² Mn2+, Cu2+, Fe3+ ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΡ ΠΊ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΡ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ. ΠΠ΅ ΠΎΠ±Π½Π°ΡΡΠΆΠ΅Π½ΠΎ ΠΊΠΎΡΡΠ΅Π»ΡΡΠΈΠΈ ΠΌΠ΅ΠΆΠ΄Ρ Π°Π½ΡΠΈΡΠ΅Π»ΠΎΠΌΠ΅ΡΠ°Π·Π½ΠΎΠΉ (Π°Π½ΡΠΈΠΏΡΠΎΠ»ΠΈΡΠ΅ΡΠ°ΡΠΈΠ²Π½ΠΎΠΉ) Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡΡ ΠΈ ΠΊΠΈΠ½Π΅ΡΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ ΡΠ²ΠΎΠΉΡΡΠ²Π°ΠΌΠΈ ΠΌΡΡΠ°Π½ΡΠ½ΡΡ
ΡΠΎΡΠΌ L-Π°ΡΠΏΠ°ΡΠ°Π³ΠΈΠ½Π°Π·Ρ RrA
Interface electronic states and boundary conditions for envelope functions
The envelope-function method with generalized boundary conditions is applied
to the description of localized and resonant interface states. A complete set
of phenomenological conditions which restrict the form of connection rules for
envelope functions is derived using the Hermiticity and symmetry requirements.
Empirical coefficients in the connection rules play role of material parameters
which characterize an internal structure of every particular heterointerface.
As an illustration we present the derivation of the most general connection
rules for the one-band effective mass and 4-band Kane models. The conditions
for the existence of Tamm-like localized interface states are established. It
is shown that a nontrivial form of the connection rules can also result in the
formation of resonant states. The most transparent manifestation of such states
is the resonant tunneling through a single-barrier heterostructure.Comment: RevTeX4, 11 pages, 5 eps figures, submitted to Phys.Rev.
Ultra-high field transport in GaN-based heterostructures
This paper describes measurements of the velocity of electrons at electric fields up to 100 kV/cm in GaN/AlGaN heterostructures. In order to avoid the Joule heating effect, a pulse technique with a time sweep of 10-30 ns was used. The experimental results indicate that overheating of the 2DEG does not exceed 1000 K in this electric field range and drift velocity as high as ~10β· cm/s was obtained. Additionally, the low frequency 1/f noise spectra measured for a different bias voltage are analyzed with respect to field-induced contribution of hopping conductivity in AlGaN barrier region
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