59 research outputs found
Cogeneration scheme of using SER of gas-processing plant
This article describes the thermal protection schemes application of the secondary resources to generate electricity, as well as the technological plan for energy disposal plant is given. The analyses of numerous research works in the sphere of thermodynamic effectiveness of power plant cycles with different working substances were presented. It is shown that the application of secondary resources provides a considerable volume of electricity for balance-of-plant needs
Double parton scattering in double logarithm approximation of perturbative QCD
Using the explicit form of the known single distribution functions (the
Green's functions) in the double logarithm approximation of perturbative QCD,
we analyze the structure of splitting diagrams as a source of double parton
perturbative correlations in the proton. The related phenomenological effects
are discussed for the conditions of the LHC experiments.Comment: 8 pages, 1 figure, Refs. and explanations added, published version
(Phys. Rev. D
A fresh look at double parton scattering
A revised formula for the inclusive cross section for double parton
scattering in terms of the modified collinear two-parton distributions
extracted from deep inelastic scattering is suggested. The possible
phenomenological issues are discussed.Comment: 6 pages, 2 figures, revtex4, discussion slightly modified, 3
references adde
Differences in In Vitro Properties of Pancreatin Preparations for Pancreatic Exocrine Insufficiency as Marketed in Russia and CIS
BACKGROUND: Pancreatic enzyme-replacement therapy (PERT), provided as pancreatin to patients with pancreatic exocrine insufficiency (PEI), is considered an essential substitute for the pivotal physiological function the pancreas fulfills in digestion. PEI involves a reduction in the synthesis and secretion of pancreatic enzymes (lipase, protease, amylase), which leads to an inadequate enzymatic response to a meal and consequently to maldigestion and malabsorption of nutrients. The efficacy of PERT is strongly dependent on enzyme activity, dissolution, and pancreatin particle size. OBJECTIVE: The physiological properties of eight pancreatin preparations (nine batches; five different brands) available in Russia and CIS (Commonwealth of Independent States: Armenia, Azerbaijan, Belarus, Kazakhstan, Kyrgyzstan, Moldova, Russia, Tajikistan, Uzbekistan) were investigated. METHODS: The lipase activity, dissolution, and particle size distribution of samples from multiple batches of pancreatin of different strengths were measured. RESULTS: Regarding lipase activities, all pancreatin preparations except Micrazim(R) matched the labeled content. Considerable differences were observed in particle size and dissolution. CONCLUSION: Pancreatin preparations available in Russia and CIS demonstrate product-to-product and batch-to-batch variability regarding the measured properties of lipase activity, dissolution, and particle size. This may impact the efficacy of PERT and therefore clinical outcomes
Excitonic effects on the two-color coherent control of interband transitions in bulk semiconductors
Quantum interference between one- and two-photon absorption pathways allows
coherent control of interband transitions in unbiased bulk semiconductors;
carrier population, carrier spin polarization, photocurrent injection, and spin
current injection may all be controlled. We extend the theory of these
processes to include the electron-hole interaction. Our focus is on photon
energies that excite carriers above the band edge, but close enough to it so
that transition amplitudes based on low order expansions in are
applicable; both allowed-allowed and allowed-forbidden two-photon transition
amplitudes are included. Analytic solutions are obtained using the effective
mass theory of Wannier excitons; degenerate bands are accounted for, but
envelope-hole coupling is neglected. We find a Coulomb enhancement of two-color
coherent control process, and relate it to the Coulomb enhancements of one- and
two-photon absorption. In addition, we find a frequency dependent phase shift
in the dependence of photocurrent and spin current on the optical phases. The
phase shift decreases monotonically from at the band edge to 0 over an
energy range governed by the exciton binding energy. It is the difference
between the partial wave phase shifts of the electron-hole envelope function
reached by one- and two-photon pathways.Comment: 31 pages, 4 figures, to be published in Phys. Rev.
Morphological peculiarites and functional activity of adipose-derived mesenchimal stem cells during in vitro cultivation conditions
The studies were conducted on 2-3-months-old males of C57BL/6 mice weighing 20–24 g. Obtaining and cultivating of adipose-derived mesenchimal stem cells (AD MSCs) were carried out in a sterile laminar box with compliance of conditions of asepsis and antiseptics. AD MSCs of the 2, 4, 7 and 12 passages were analyzed. Morphometric analysis was performed using a light microscopy. Morphometric parameters such as cell and nucleus area or nuclear-cytoplasmic ratio (NCR) were calculated using the Axiovision light microscope (Carl Zeiss, Germany) and ImageJ 1.45 software. Trypan blue dye used for investigation of the viability of MSC. The morphological characteristics of mesenchymal stem cells from adipose tissue during the process of cultivation changes: at the first passages of cultivation, the cells are spindle-shaped with two, at least three, long long cytoplasmic processes, located bipolar. Near the nucleus the Golgi complex is clearly visible – a sign of active cells. At later passages cells have a small cytoplasmic processes and the bipolar arrangement of processes changes by stellar arrangement. Golgi complex is also clearly visualized. The indicator of the nuclear-cytoplasmic ratio in MSC from adipose tissue is significantly reduced at 7 passage to 0.2189 ± 0.0122 (P < 0.01), and at 12 passage to 0.1111 ± 0.0086 (P < 0.001) compared to the 2 passage. The coefficient of proliferation of MSC from adipose tissue is significantly reduced at 12th passage. The viability of mesenchymal stem cells from adipose tissue with an increasing of a number of passages significantly reduces and at the 12th passage of cultivation reaches 84,67 ± 1,36* (P < 0.05). The content of apoptotic cells that exhibited sensitivity to serum-free significantly increased at 7 and 12 passages and was respectively 21.33 ± 1.36 (P < 0.05) and 23.67 ± 0.97% (P < 0.05)
Derivation of the Boltzmann equation and entropy production in functional mechanics
A derivation of the Boltzmann equation from the Liouville equation by the use
of the Grad limiting procedure in a finite volume is proposed. We introduce two
scales of space-time: macro- and microscale and use the BBGKY hierarchy and the
functional formulation of classical mechanics. According to the functional
approach to mechanics, a state of a system of particles is formed from the
measurements, which are rational numbers. Hence, one can speak about the
accuracy of the initial probability density function in the Liouville equation.
We assume that the initial data for the microscopic density functions are
assigned by the macroscopic one (so, one can say about a kind of hierarchy and
subordination of the microscale to the macroscale) and derive the Boltzmann
equation, which leads to the entropy production.Comment: 14 page
The first experience of a hybrid approach in the surgical treatment of atrial fibrillation
Background: Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is associated with an increased risk of death, progression of heart failure, and the development of cardiogenic thromboemboli. Despite the significant success in the management of AF in the paroxysmal form, the results of the treatment for patients with persistent forms of AF remain unsatisfactory. Though the surgical approach provides higher rates of efficiency regarding the restoration of a sinus rhythm, transmural lesions are not always attainable, as a result, the rate of AF recurrence in the long-term period remains fairly high. It is also impossible to create ablative patterns to the mitral and tricuspid valves during thoracoscopic epicardial ablation, which can cause the development of recurrent AF, perimitral and typical atrial flutter. Therefore, the development of hybrid approaches combining the advantages of catheter and thoracoscopic techniques is an urgent task of contemporary surgical and interventional arrhythmology.
Aims: to estimate the immediate results of a hybrid approach in the management of patients with persistent AF.
Methods: We report the first experience of a hybrid treatment of patients with persistent AF. 6 patients aged 53-64 years (1 female, 5 males) were included in the study. At the first stage, thoracoscopic epicardial bipolar ablation was performed (modified GALAXY protocol); the second stage (in 3 to 6 months after the thoracoscopic stage) included an intracardiac electrophysiological study with three-dimensional endocardial mapping followed by endocardial ablation.
Results: The thoracoscopic stage of the hybrid treatment included ablation according to the box lesion scheme using a bipolar irrigation equipment. No lethal outcomes and severe, life-threatening complications were registered. The duration of the inpatient period was 510 hospital-days. The 2nd stage of the hybrid treatment was limited to intracardiac electrophysiological examination only in 2 patients. In 4 patients, epicardial radiofrequency ablation was complemented by endocardial radiofrequency exposure. In 3 of the 4 patients who underwent endocardial radiofrequency ablation, catheter ablation of the mitral and cavotricuspid isthmus was required because of the induction of perimitral and typical flutter, respectively. After the 2nd stage of the hybrid treatment, at the time of discharge all the patients maintained a stable sinus rhythm. There were no severe complications or lethal outcomes.
Conclusion: a hybrid approach in the AF management is a safe and effective method of treatment, which combines the advantages of minimally invasive surgery and endocardial intervention in patients with persistent AF. The technique is safe and has acceptable short-term results
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