256 research outputs found
Gaussian modeling and Schmidt modes of SPDS biphoton states
A double-Gaussian model and the Schmidt modes are found for the biphoton wave
function characterizing spontaneous parametric down-conversion with the
degenerate collinear phase-matching of the type I and with a pulsed pump. The
obtained results are valid for all durations of the pump pulses, short, long
and intermediately long
Projectile fragmentation at Fermi energies with transport simulations
Projectile fragmentation at Fermi energies is an important method to produce radioactive beams for the study of isospin asymmetric nuclear matter. Fragmentation is usually parametrized successfully by empirical phase space models. In this contribution we apply a microscopical method, semiclassical transport theory, to study in detail the reaction mechanism of the fragmentation process. We apply it to experimental data of 18O on 181Ta at E/A = 35 MeV measured in Dubna. We calculate consistently the excitation energy of the primary fragments and take into account their decay by a statistical model. It is found that the dissipative part of the fragment spectra is well described by transport theory. However, there are in addition important direct and collective contributions
TREATMENT OF INSUFFICIENT JOINT EXTENSOR MECHANISM IN PRIMARY AND REVISION KNEE REPLACEMENT
Insufficiency of the knee joint extensor mechanism is the absolute contraindication for total knee arthroplasty. Therefore, it is necessary to restore the extensor mechanism before arthroplasty or to change the treatment approach.Purpose of the study – to evaluate the outcomes of surgical reconstruction of the knee joint extensor mechanism during primary or revision knee arthroplasty.Materials and methods. 25 reconstructions of extensor mechanisms (24 patients) were performed in the period from 2006 to 2015. Five procedures out of 25 were performed in primary TKA and 20 in revision TKA. Indications for extensor mechanism reconstruction were as follows: patellar tendon rupture in 15 cases (60,0%), fracture of patella in 5 cases (20,0%), quadriceps tendon rupture in 3 cases (12,0%) and other indications in 2 cases (8,0%). One of the following four techniques was used to restore the extensor mechanism: “Frame / Loop” allograft of patellar tendon in 6 cases (24,0%); bone – patellar tendon – bone allograft in 9 cases (36,0%); quadriceps tendon – patella-patellar tendon – bone allografts in 7 cases (28,0%); weber’s internal fixation of patella in 3 cases (12,0%).Results. All patients were evaluated based on clinical examination, KSS and WOMAC scores (18 patients), and standard x-rays (13 patients). The mean follow-up period in the present study was 44 months postoperatively. Reconstruction of the knee joint extensor mechanism resulted in a significant reduction of pain in 38.8% of patients, the knee stability was restored in 83,3% of patients and the active knee extension improved significantly in the vast majority of patients.Conclusion. Despite the objective improvement of the knee joint function after the reconstructions of extensor mechanism, the KSS and WOMAC evaluation scores remained low which should be taken into consideration during preoperative planning
Obstructive sleep apnea syndrome and cardiovascular risk factors in the antihypertensive therapy “escape” phenomenon
Aim. To assess the role of obstructive sleep apnea and other cardiovascular (CV) risk factors in the development of the antihypertensive therapy (AHT) efficacy escape phenomenon in patients with arterial hypertension (AH).
Materials and methods. The data of 75 patients with AH stage III, grades 13 were proceeded. All patients included in the study underwent night respiratory monitoring. After AHT prescription, blood pressure (BP) was monitored by three measurement methods (office, daily monitoring and self-control of blood pressure) initially, in 1, 3 and 6 months after the inclusion in order to confirm the initial therapy efficacy and to identify or exclude the escape phenomenon.
Results. In 36.0% of patients, the escape phenomenon was diagnosed in 1 or 3 months of observation. When comparing the group with the escape phenomenon, an initially higher level of systolic BP was revealed according to office measurements, 24-hour monitoring and self-control BP monitoring (134.04.7 mmHg vs 126.08.5 mmHg; 129.02.3 mmHg vs 121.07.7 mmHg; 131.08.2 mmHg vs 121.56.2 mmHg resp.; р0,05). There were no differences in sleep apnea and CV risk factors between the groups. However in patients with a minimal SpO285% during sleep, there were a higher levels of office systolic BP both before the AHT prescription, and during its use (157.610.4 mmHg vs 152.48.1 mmHg resp., р0,05; 132.06.8 vs 127.18.9 mmHg resp.; р0,05), and mean 24-hour systolic BP (125.75.9 vs 121.68.2 mmHg resp.; р0,05) compared with patients with a minimum SpO285%.
Conclusion. The higher BP level in patients with lover nocturnal hypoxemia does not allow us to exclude the delayed negative impact of obstructive sleep apnea, especially severe, on the BP profile in case of initially successful AH control
The research of uranium monoxide-oxide dissolution process in nitric acid
The kinetics of concentrates of uranium monoxide-oxide dissolution process by nitric acid solutions of 5...9 mole/l in the range of 11...90 °C has been studied. It is stated that initial nitric acid concentration increasing results in some uranium dissolution degree increasing only at the first process stage. Temperature increasing significantly raises uranium dissolution degree at the first stage as well. Uranium dissolution degree increases for all studied temperatures with increasing of the process period. The main feature of the studied process is that while dissolving uranium monoxide-oxide the behavior of iron, molybdenum, silicon additives is adequate to that of uranium. The equation of the reducing sphere describes the uranium leaching process from its nitric acid concentrate
Characteristics of erythropoietin antibodies in patients treated with recombinant human erythropoietin
Our aim was to characterize anti-EPO antibodies in serum samples of the patients treated with erythropoietin. 106 serum samples from the patients treated with erythropoietin (EPO) were collected and assayed. 134 serum samples of patients who did not receive EPO were taken for comparative analysis. The anti-EPO antibody detection was performed in ELISA test with rhEPO, by passive capture on ELISA plates, using steptavidin-biotin immunochemical system. Mouse monoclonal antibodies to human IgG, IgG1, IgG2, IgG3 and IgG4 conjugated to horseradish peroxidase were used to detect anti-EPO antibodies, and protein-A peroxidase conjugate was used for quantitative assays. Rabbit anti-human EPO polyclonal antibodies at known concentrations were used as a calibration standard. Six calibration samples at the concentration range of 16-1000 ng/ml were used to plot calibration curves. The lower detection limit was 12 ng/mL, and the quantitative detection limit was 31 ng/ml. Immunochemical capturing led to increasing of total IgG antibody detection by 3.2 times, IgG1 – by 1.1 times IgG2 – by 1.25 times, IgG3 – by 1.5 times, IgG4 – by 1.7 times. Antibodies of mixed isotype were found in most patients. IgG1 or IgG4 antibodies to EPO were determined only in 3 samples. Specific IgM was not detectable among 106 sera samples, whereas total IgG antibodies were detected in 36.8 % of cases. In 34% of sera, their presence was confirmed by detection of at least one of the subclasses. IgG1 antibody was detected in 83.3%; IgG4, in 80.6% of the samples positive for total IgG antibodies. In all cases, IgG2 and/or IgG3 were detected in presence of IgG1 or IgG4 antibodies. The antibody concentration was 3.2 to 35.5 µg/mL in sera from 28 patients, in 8 cases the level of antibodies was > 50 µg/ml, however, being below the limit of quantitative detection in 3 patients. Only 6 samples contained antibodies with avidity index of > 50%. Immunochemical capturing of the antigen led to increased sensitivity for detecting all subclasses of specific antibodies. The specific IgG antibodies to EPO were found in more than 1/3 of serum samples from the patients treated with erythropoietin. Low-avidity antibodies of IgG1 and IgG4 subclasses were determined in most cases
Financial Planning as the Most Important Element in the Enterprise Management System
The modern development of a market economy dictates its own requirements for economic units, the effectiveness of which directly depends on the implementation of financial policy and its planning. Planning, in turn, allows you to determine the prospect of the enterprise, that is, to foresee its future and avoid possible risks. As an example, the article considers financial planning within the banking sector.Современное развитие рыночной экономики диктует свои требования к хозяйственным единицам, эффективность которых напрямую зависит от реализации финансовой политики и ее планирования. Планирование в свою очередь позволяет определить перспективу предприятия, то есть предвидеть его будущее и избежать возможных рисков. В качестве примера в статье рассмотрено финансовое планирование в рамках банковского сектора
Capabilities of the GAMMA-400 gamma-ray telescope to detect gamma-ray bursts from lateral directions
The currently developing space-based gamma-ray telescope GAMMA-400 will
measure the gamma-ray and electrons + positrons fluxes using the main top-down
aperture in the energy range from ~20 MeV to several TeV in the highly elliptic
orbit (without shadowing the telescope by the Earth and outside the radiation
belts) continuously for a long time. The instrument will provide fundamentally
new data on discrete gamma-ray sources, gamma-ray bursts (GRBs), sources and
propagation of Galactic cosmic rays and signatures of dark matter due to its
unique angular and energy resolutions in the wide energy range. The gamma-ray
telescope consists of the anticoincidence system (AC), the converter-tracker
(C), the time-of-flight system (S1 and S2), the position-sensitive and
electromagnetic calorimeters (CC1 and CC2), the top and bottom scintillation
detectors of the calorimeter (S3 and S4) and lateral detectors of the
calorimeter (LD). In this paper, the capabilities of the GAMMA-400 gamma-ray
telescope to measure fluxes of GRBs from lateral directions of CC2 are analyzed
using Monte-Carlo simulations. The analysis is based on second-level trigger
construction using signals from S3, CC2, S4 and LD detectors. For checking the
numerical algorithm the data from space-based GBM and LAT instruments of the
Fermi experiment are used, namely, three long bursts: GRB 080916C, GRB 090902B,
GRB 090926A and one short burst GRB 090510A. The obtained results allow us to
conclude that from lateral directions the GAMMA-400 space-based gamma-ray
telescope will reliably measure the spectra of bright GRBs in the energy range
from ~10 to ~100 MeV with the effective area of about 0.13 m2 (for each of the
four sides of CC2) and total field of view of about 6 sr.Comment: 19 pages, 18 figures, the paper will be submitted to Advances in
Space Researc
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