Impact ionization fronts in Si diodes: Numerical evidence of superfast propagation due to nonlocalized preionization

We present numerical evidence of a novel propagation mode for superfast impact ionization fronts in high-voltage Si $p^+$-$n$-$n^+$ structures. In nonlinear dynamics terms, this mode corresponds to a pulled front propagating into an unstable state in the regime of nonlocalized initial conditions. Before the front starts to travel, field-ehanced emission of electrons from deep-level impurities preionizes initially depleted $n$ base creating spatially nonuniform free carriers profile. Impact ionization takes place in the whole high-field region. We find two ionizing fronts that propagate in opposite directions with velocities up to 10 times higher than the saturated drift velocity.Comment: 3 pages, 4 figure

Theory of superfast fronts of impact ionization in semiconductor structures

We present an analytical theory for impact ionization fronts in reversely biased p^{+}-n-n^{+} structures. The front propagates into a depleted n base with a velocity that exceeds the saturated drift velocity. The front passage generates a dense electron-hole plasma and in this way switches the structure from low to high conductivity. For a planar front we determine the concentration of the generated plasma, the maximum electric field, the front width and the voltage over the n base as functions of front velocity and doping of the n base. Theory takes into account that drift velocities and impact ionization coefficients differ between electrons and holes, and it makes quantitative predictions for any semiconductor material possible.Comment: 18 pagers, 10 figure

Soliton dual comb in crystalline microresonators

We present a novel compact dual-comb source based on a monolithic optical crystalline MgF$_2$ multi-resonator stack. The coherent soliton combs generated in two microresonators of the stack with the repetition rate of 12.1 GHz and difference of 1.62 MHz provided after heterodyning a 300 MHz wide radio-frequency comb. Analogous system can be used for dual-comb spectroscopy, coherent LIDAR applications and massively parallel optical communications.Comment: 5 pages, 5 figure

To the practical design of the optical lever intracavity topology of gravitational-wave detectors

The QND intracavity topologies of gravitational-wave detectors proposed several years ago allow, in principle, to obtain sensitivity significantly better than the Standard Quantum Limit using relatively small anount of optical pumping power. In this article we consider an improved more ``practical'' version of the optical lever intracavity scheme. It differs from the original version by the symmetry which allows to suppress influence of the input light amplitude fluctuation. In addition, it provides the means to inject optical pumping inside the scheme without increase of optical losses. We consider also sensitivity limitations imposed by the local meter which is the key element of the intracavity topologies. Two variants of the local meter are analyzed, which are based on the spectral variation measurement and on the Discrete Sampling Variation Measurement, correspondingly. The former one, while can not be considered as a candidate for a practical implementation, allows, in principle, to obtain the best sensitivity and thus can be considered as an ideal ``asymptotic case'' for all other schemes. The DSVM-based local meter can be considered as a realistic scheme but its sensitivity, unfortunately, is by far not so good just due to a couple of peculiar numeric factors specific for this scheme. From our point of view search of new methods of mechanical QND measurements probably based on improved DSVM scheme or which combine the local meter with the pondermotive squeezing technique, is necessary.Comment: 27 pages, 6 figure

Comparison of survival rates made by the 6-th and 7-th editions of TNM classification in stomach cancer patients

The available classifications of malignant tumors reflect various aspects of their growth and some biological features. The most commonly used in Ukraine is the 6-th revision of TNM classification, which differs from the previous classifications of the section "Gastric cancer", mainly staging of category N, reflecting the presence of metastases in regional lymph nodes. Transition to the 7-th classification of TNM translates a part of patients from one stage to another, there is a so-called "stage migration" phenomenon. The famous mathematical phenomenon of Will Rogers describes this transition and theoretically substantiates its objectivity. The authors tracked the migration of patients and the change in the stage mainly from the point of view of the effect of this event on the survival of patients with stomach cancer

Analysis of survival after radical surgery for stomach cancer in odessa regional cancer center

The survival of patients with the locally advanced stage of stomach cancer (SC), who underwent various variants of preventive lymphatic nodes dissection, was considered. The survival of patients was compared with the stage and T, N indexes. Lymphadenectomy D2 were effective and increased cumulative survival in patient`s group T4aNoMo, stage IIB and T4aN1Mo, stage III A, and in groups of patients where D2 lymphadenectomy were ineffective - T4bNoMo, stage ІІІB, T4bN1Мo, stage ІІІB and T4aN2Мo, stage IIIB. D2 were more efficient operation in the case of tumor serosa invasion and invasion to the peritoneal cavity (SE) in the absence of multiple metastases to the regional lymph nodes (N1 according to the 7th revision of the classification - 1-2 metastatic lymph nodes), and when the tumor infiltrated the surrounding organs (SI) and the presence of multiple regional metastases, D2 lymphodissection did not gave positive results, comparising with D1

Optimizing the regimes of Advanced LIGO gravitational wave detector for multiple source types

We develop here algorithms which allow to find regimes of signal-recycled Fabry-Perot--Michelson interferometer (for example, Advanced LIGO), optimized concurrently for two (binary inspirals + bursts) and three (binary inspirals + bursts + millisecond pulsars) types of gravitational waves sources. We show that there exists a relatevely large area in the interferometer parameters space where the detector sensitivity to the first two kinds of sources differs only by a few percent from the maximal ones for each kind of source. In particular, there exists a specific regime where this difference is ~0.5 for both of them. Furthermore we show that even more multipurpose regimes are also possible, that provide significant sensitivity gain for millisecond pulsars with only minor sensitivity degradation for binary inspirals and bursts.Comment: 10 pages, 14 figures, 3 tables. Minor corrections in main text are done in version 2 and two plots and one table are added for the sake of clarity of the obtained result

Significance of basic clinical tests changing after the Hypec procedure in patients with gastric cancer and some other tumors

Hyperthermic intraperitoneal chemotherapy is a popular method of palliative treatment in patients with malignant abdominal tumors. This review is devoted to trace changes in general clinical tests in patients with carcinomatosis. The patients were operated on at the Clinic of Reconstructive and Plastic Medicine of the Odessa National Medical University. All patients satisfactorily tolerated this procedure. The object of the study was to track those changes with patients that took place in the immediate (prior to discharge) postoperative period. 25 patients have recruited to the study. In the group changes in 11 basic clinical and laboratory parameters among those included were monitored in the study. Hemoglobin, leukocytes, platelets, total protein, bilirubin, serum glucose concentration, liver enzymes alanine aminotransferase and aspartate aminotransferase levels, thymol test and coagulogram indices. Thus, the most significant indicators, such as the concentration of hemoglobin, leukocytes and platelets, have not undergone significant changes after HIPEC. Hemoglobin decreased by 6 units (g / l), the concentration of leukocytes, on the contrary, increased by 2 units (T/l), platelet levels dropped by 61 units (also G/l). The concentration of total protein decreased by 7 units. The concentration of total bilirubin practically did not change, decreasing by about 1 unit. Indicators of AST and ALT did not increase, decreasing by 8 and 3 units, respectively. The average concentration value of blood glucose level slightly increased by almost 1 unit. Thymol levels have not changed. The prothrombin index decreased by 3 units; the concentration of fibrinogen in serum remained at approximately the same level. HIPEC procedure does not significantly affect the clinical and laboratory parameters. However, the tendency of this category of patients to hypercoagulation, hypoproteinemia and hyperglucosemia was noted

Lymph node dissection impact on long-term survival rate of gastric cancer patients in Ukraine

Over a period of 2007-2011 188 stomach cancer (SC) patients have been included in the research in abdominal oncosurgical department of Odessa oncological center. Volume of lymph node dissections differed by quantity of lymph nodes to be removed. All patients were divided into three groups. Patients with D1 or D1+ lymph node dissections have been performed, totally 90 patients are included in group of historical control. In all cases so-called lymph node dissections for principal reasons have been executed. The multifactorial analysis of patients survival is implemented depending on a type of a lymph node dissections, a stage of the cancer, number of involved lymph nodes, involvement of the tumoral microcirculatory net (ly is carried out, v) signs of a perinevral invasion (Nev), availability of residual tumoral tissue (R), degree of a differentiation (G). Regardless of a disease stage, SC at 60 % of patients, represented with initially hematologicaly disseminated disease. 40 % of SC`s had no signs of intratumoral microcirculatory net involvement even in case of more than 15 regional lymph nodes are involved