Theoretical study of important bulk properties of nuclei far from stability such us the nuclear skin and its correlation with the density dependence of the symmetry energy in uniform matter is reviewed. The formation of neutron skin and its evolution with an increase of the neutron number is investigated on the basis of a self-consistent deformed mean-field Hartree - Fock method using density-dependent Skyrme force sand pairing correlations in BCS approach. We study isotopic chains of Ni, Kr, and Sn nuclei and consider all the experimentally observed isotopes from neutron-deficien to neutron-rich ones. Various definition of the neutron skin thickness based on the differences between neutron and proton radii as well as on comparison of the tail soft he neutron and proton density distributions have been tested. The effects of deformation on the neutron skins in even-even deformed nuclei are discussed on the example of Kr isotopes. The symmetry energy, the neutron pressure and the asymmetric compressibility of spherical Ni, Sn, and Pb and deformed Kr and Sm neutron-rich even-even nuclei are calculated within the coherent density fluctuation model using the symmetry energy as a function of density within the Brueckner energy-density functional. The correlation between the thickness of the neutron skin and the characteristics related with the density dependence of the nuclear symmetry energy is investigated for isotopic chains of these nuclei. The mass dependence of the nuclear symmetry energy and the neutron skin thickness are also studied together with the role of the neutron-proton asymmetry. The studied correlations reveal a smoother behavior in the case of spherical nuclei than for deformed ones. We also note that the neutron skin thickness obtained for <^>208Pb with SLy4 force is found to be in a good agreement with the recent data. In addition, we analyse the existence of peculiarities of the studied quantities in Ni and Sn isotopic chains that are not present in the Pb chain.

Behaviour of the equilibrium interval of the wave frequency spectrum is investigated. It is argued that spectra of Phillips, Toba and Zakharov-Filonenko are consistent with each other, and transition between <$E f sup -4> and <$E f sup -5> subintervals is parameterised by means of field data including those obtained at short fetches from Katsiveli research tower. Role of the wave breaking, wind input and nonlinear interactions in formation of the spectrum tail is discussed.

To date, genome instability is considered to be a common feature not only of tumor cells, but also of non-malignant cells of cancer patients, including peripheral blood lymphocytes (PBLs). The issue of the association between genome instability in tumor cells and PBLs, as well as of its relationship with tumor progression remains poorly understood. Aim - to evaluate the level DNA damage in tumor cells and PBLs of endometrial cancer (EC) patients with regard to clinical and morphological characteristics of the patients. DNA damage was assessed in 106 PBLs samples and 42 samples of tumor cell suspension from EC patients by comet assay. PBLs from 30 healthy women were used as control. The level of DNA damage was expressed as the percentage of DNA in the comet tails (% tail DNA). Results: it was revealed that the amount of DNA damage in PBLs of EC patients was 2,2 times higher in comparison with that of healthy donors (8,3 +- 0,7 and 3,7 +- 0,4 % tail DNA, respectively) (p << 0,05). In this study, no association between the levels of DNA damage in endometrial tumor cells and PBLs was observed (r = 0,11 ; p >> 0,05). The amounts of DNA damage both in tumor cells and PBLs were not related to the degree of tumor differentiation as well as the depth of myometrial invasion, but depended on the body mass index (BMI) of EC patients: high level of lesions was observed in patients with elevated BMI values. Furthermore, the level of DNA damage in tumor cells was associated to familial aggregation of cancer and was significantly higher in endometrial cells from patients with family history of cancer vs that from EC patients with sporadic tumors (32,3 +- 2,9 and 22,8 +- 1,8 % tail DNA, respectively) (p << 0,05). It was also found that for women who had high level of DNA damage in PBLs, the risk of EC was greater (odds ratio value of 3,5) compared to those with low level of such lesions. Conclusion: genome instability that appears as an increased level of DNA damage in tumor cells and PBLs of EC patients is associated with BMI and family history of cancer and can reflect a predisposition to cancer.

Background - the development of hormone-dependent cancers, including endometrial carcinomas, in great part may be mediated by the genotoxic effects of estrogen metabolites, among which 4-hydroxyestradiol (4OHE2) is characterized by the most prominent DNA-damaging properties. It is assumed that the individual sensitivity to the 4OHE2 may determine the predisposition to endometrial cancer (EС). Aim - to analyze the sensitivity of peripheral blood lymphocytes (PBLs) of EC patients to the 4OHE2 and to evaluate the repair efficiency of 4OHE2-induced DNA damage. The study was performed on the PBLs of 53 EC patients and 20 healthy women. The level of DNA damage was measured using the comet assay and was expressed as % tail DNA. The DNA repair efficiency (%) was evaluated by determining the ratio between the amount of repaired DNA damage and the level of 4OHE2-induced damage that appeared after incubation of PBLs with 4OHE2. In PBLs of EC patients, a higher level of 4OHE2-induced DNA damage (32,0 +- 2,2 % tail DNA) and lower DNA repair efficiency (34,0 +- 4,5 %) was observed compared to PBLs of healthy women (22,3 +- 2,3 % tail DNA and 48,8 +- 4,5 %, respectively). PBLs of EC patients with deep tumor invasion of myometrium were characterized by more prominent decrease of DNA repair than those with less invasive tumor (<< 1/2 of myometrium) (20,9 +- 7,8 and 43,7 +- 6,7 %, respectively). Furthermore, lower DNA repair efficiency was detected in the PBLs of EC patients with a family history of cancer compared to this parameter in patients with sporadic tumors (20,9 +- 7,8 and 47,1 +- 5,5 %, respectively). Conclusion: the PBLs of EC patients are characterized by increased sensitivity to the genotoxic effect of 4OHE2 and reduced repair efficiency regarding 4OHE2-induced DNA damage. A lower level of DNA repair is observed in EC patients with deep tumor myometrial invasion and a family history of cancer.

Центральное ядро амигдалярного комплекса (Ce) является структурой, в которой заканчивается один из важнейших ноцицептивных путей, спино (тригемино)-парабрахио-амигдалярный тракт. В экспериментах на белых крысах-самцах Ce билатерально электролитически разрушалось. Уровень ноцицепции оценен по значениям латентного периода реакции отдергивания хвоста, которые сравнивали с соответствующими величинами у интактных и псевдооперированных крыс. Стереотаксическая билатеральная электролитическая коагуляция Се существенно снижала болевую чувствительность. Кроме того, изменения болевой чувствительности в пределах дня, характерные для контрольных животных, заметно сглаживались.

Aim - to investigate the influence of exogenous lactoferrin (LF) on tumor growth, energy and lipid metabolism of Walker-256 carcinosarcoma and to assess genotoxic effects of LF. The study was performed on Walker-256 tumor-bearing rats. Total lipids and phospholipids were determined by thin-layer chromatography. Comet assay was used to investigate the genotoxic effects of LF. Daily i.p. administrations of exogenous LF at concentrations of 1 mg/kg and 10 mg/kg starting from the 4<^>th day after tumor transplantation suppressed growth of Walker-256 carcinosarcoma by almost 44 %. After treatment with recombinant LF in both doses, the phospholipid composition of Walker-256 carcinosarcoma cells was changed (3-fold increase of phosphatidylethanolamine, 3.4-fold increase of phosphatidylcholine, and 1.8-fold increase of sphingomyelin, while the cardiolipin content decreased by 67 %. Exogenous LF was not genotoxic for bone marrow cells (as assessed by the ratio of PCE/NCE, number of micronuclei) and peripheral blood lymphocytes (percentage of DNA in the tail of a comet) in Walker-256 carcinosarcoma-bearing rats. Conclusion: exogenous LF caused the inhibition of Walker-256 carcinosarcoma growth and a decrease in the microviscosity of plasma cell membranes, and exerted no genotoxicity toward bone marrow cells and peripheral blood of experimental animals.

Fullerene C60 films were grown using physical vapor deposition on Si substrates at room temperature. Then chemical modification with cross-linking these films was performed using the reaction with 1,8-octanediamine (DA) or octane-1,8-dithiol (DT). These chemically cross-linked C60 films are capable of stable binding the Ag or Au nanoclusters. Optical properties of the obtained nanostructured hybrid films were investigated by both reflectance spectroscopy and spectral ellipsometry within the spectral range 1,55 to 5,0 eV at various angles of incidence. From the spectral dependences of the extinction coefficient in the region of optical absorption edge, the physical nature of the fundamental allowed direct band-gap transitions between HOMO-LUMO states <$E E sub g>, the optical absorption edge near the intrinsic transition <$E E sub o>, and exponential tail of the density-of-states caused by defects have been determined. Influence of chemical modification and decoration of metal nanoparticles on the above mentioned parameters has been analyzed.

We present an explicit water molecular dynamics simulation of dilute solutions of model alkyltrimethylammonium surfactant ions (number of methylene groups in the tail is 3, 5, 8, 10, and 12) in mixture with NaF, NaCl, NaBr, and NaI salts, respectively. The SPC/E model is used to describe water molecules. Results of the simulation at 298 K are presented in the form of radial distribution functions between nitrogen and carbon atoms of CH2 groups on the alkyltrimethylammonium ion, and the counterion species in the solution. The running coordination numbers between carbon atoms of surfactants and counterions are also calculated. We show that I<^>- counterion exhibits the highest, and F<^>- the lowest affinity to "bind" to the model surfactants. The results are discussed in view of the available experimental and simulation data for this and similar solutions.

The model-independent part of the radiative corrections, due to the hard-photon emission from the lepton vertex in the elastic electron-deuteron scattering (the so-called elastic radiative tail), has been calculated to the deep inelastic scattering of the electron beam on the deuteron target. The elastic radiative tail has been calculated both for the unpolarized scattering and for the scattering of unpolarized electron beam on the tensor polarized deuteron target.

The aim of present study was to develop a model for a functional analysis of a recently identified marker of the ovarian cancer - sodium-dependent phosphate transporter NaPi2b. For this purpose, we have created HEK293 stable cell lines expressing wild type or mutant forms of NaPi2b (T330V substitution in a large extracellular loop and a 6 amino acid residues deletion in the C-terminal cytoplasmic tail), revealed in the ovarian cancer cell lines. The expression of wild type and mutant forms NaPi2b in the stable cell lines created was confirmed by Western-blot analysis with monoclonal antibodies against NaPi2b. The cellular models described here will be useful for studying the function of sodium-dependent phosphate transporter NaPi2b in health and disease.

A computer model to simulate hybrid solar cells based on hydrogenated amorphous silicon carbide (a-SiC:H) and crystalline silicon (c-Si) was developed. Using the developed approach, the current-voltage characteristics of p(n) a-SiC:H/n(p) c-Si heterojunction solar cells were analyzed. It was shown that the maximum cell efficiency of the p - n and n - p tandems is observed for the amorphous layer thickness ~ 0,03 - 0,06 and 0,01 - 0,03 <$E mu>m, respectively. The efficiency of the n - p heterojunctions is found to be higher than that of the p - n tandem by approximately 1,5 %. This is attributed to the fact that, in n-doped a-SiC:H, the conductive band tail is narrower compared to the valence band one in p-doped films. The simulated results are compared with the available experimental data obtained with a-SiC:H/c-Si heterostructures.

We search for marginal Fermi-liquid behavior in the two-band Hubbard model with one narrow band. We consider the limit of low electron densities in the bands and strong intraband and interband Hubbard interactions. We analyze the influence of electron - polaron effect and other mechanisms of mass-enhancement (related to momentum dependence of the self-energies) on effective mass and scattering times of light and heavy components in the clean case (electron - electron scattering and no impurities). We find the tendency towards phase-separation (towards negative partial compressibility of heavy particles) in a 3D case for large mismatch between the densities of heavy and light bands in a strong coupling limit. We also observe that for low temperatures and equal densities the resistivity in a homogeneous state R(T) ~ T<^>2 behaves in a Fermi-liquid fashion both in 3D and 2D cases. For temperatures higher then effective bandwidth for heavy electrons <$E T~>>~W sub h sup *> the coherent behavior of heavy component is totally destroyed. The heavy particles move diffusively in the surrounding of light particles. In the same time the light particles scatter on the heavy ones as if on immobile (static) impurities. In this regime the heavy component is marginal, while the light one is not. The resistivity goes on saturation for <$E T~>>~W sub h sup *> in the 3D case. In 2D the resistivity has a maximum and localization tail due to weak-localization corrections of Altshuler - Aronov type. Such behavior of resistivity in 3D could be relevant for some uranium-based heavy-fermion compounds like UNi2Al3

and in 2D for some other mixed-valence compounds possibly including the layered manganites. We also consider briefly the superconductive (SC) instability in the model. The leading instability is towards p-wave pairing and is governed by enhanced Kohn - Luttinger mechanism of SC at low electron density. The critical temperature corresponds to the pairing of heavy electrons via polarization of the light ones in 2D.

Індекс рубрикатора НБУВ: В317.23 + В317.242

Рубрики:

Квантова статистика

Теорія фазових переходів 2 роду

Шифр НБУВ: Ж14063 Пошук видання у каталогах НБУВ 
Повний текст  Наукова періодика України 

Background: intraoperative ultrasound examination (IOUS) is indispensable part of modem surgical interventions in tumors of hepatopancreatobiliary zone. In this study retrospective analysis of IOUS efficiency in surgical treatment of pancreatic tumors was provided. In the period from January 2013 till November 2015 in the National Cancer Institute IOUS was applied during 76 surgical interventions: for pancreatic head tumors - in 46 (60,5 %) patients, for body/tail pancreatic tumors - in 20 (26,3 %) patients, in 10 (13,2 %) patients - for periampullary zone neoplasms. In IOUS we performed primary tumor assessment (localization, degree of tumor spreading to superior mesenteric vessels, hepatoduodenal ligament vessels, additional foci occurrence in pancreas), and liver metastases detection. Surgical interventions were performed: pancreatoduodenectomy in 52 (68,4 %) patients, radical antegrade modal pancreatosplenectomy - in 14 (18,4 %) patients. IOUS allowed determining additional tumor foci in pancreas in 2 (2,6 %) patients, in 8 (10,5 %) observations tumor invasion into portal or superior mesenteric vein was determined. In 21 (27,6 %) patient additional hepatic neoplasms were detected (in half of cases - 11,8 %, metastases). These findings resulted in change of surgical intervention extent in 23 (30,3 %) patients: expansion to combined resections in 14 (18,4 %) patients, reduction to symptomatic operations in 5 (6,6 %) cases, organ-preserving operations were performed in 4 (5,3 %) patients. Variant anatomy of hepatic arterial blood supply was determined in 41 (53,9 %) patients that necessitated performance correction of resection stages for preservation of adequate hepatic blood supply. Conclusions: IOUS is a highly-precise diagnostic method substantively influencing operation course in pancreatic tumors, enabling surgeon to provide adequate staging and permanent correction of operation course.

Influence of light polarization on absorption saturation for wurtzite modification CdSe has been investigated. It has been ascertained that the size of blurring the fundamental absorption edge for wurtzite modification CdSe is determined by the non-equilibrium electron filling both the conduction band extremum, when the energy of photons <$Eh nu> is higher than the bandgap energy Eg, and the density-of-state tail caused by the presence of static disorder, when the <$Eh nu~<<~E sub g>. The density-of-state tail resulting from the presence of dynamic disorder is not filled with electrons because of continuous changes of the dynamic potential relief value in time. In the high-energy spectral region, change in the absorption coefficient is limited by the stimulated emission processes.

The effects of long-term administration of phytoestrogens (PEs), genistein (Gen) and naringenin (Nar), on nociception, imflammatory hyperalgesia, and metamizol-induced analgesia, the efficacy of PEs vs 17<$E beta>-E to modulate nociception, as well as the gender dependency of PE effects, and NOS and TH (NO synthase and tyrosine hydroxylase, respectively) expression in the periaqueductal gray (PAG) were studied in gonadectomized female and male rats. The paw pressure, tail flick, and hot plate tests, incapacitance test, and plethismometry were employed for in vivo studies. For in vitro studies, immuno- or histochemical staining of NOS and TH expression in PAG were applied. Data revealed that PEs like 17<$E beta>-E dicreased nociceptive thresholds in both sexes, but more significantly in the female rats. Genistein intensified carrageenan-induced exudative inflammatory reaction and modulated metamizol-induced analgesia. The long-term PE administration resulted in gender-specific alterations of NO and TH expression. The effects of PEs might correlate to gender-specific 17<$E beta>-E-like action in male and female individuals. The results suggest that, similarly to other estrogen-like compounds, PEs can play a significant role in the individualization of analgesic therapy.

AMPS-1D (Analysis of Microelectronic and Photonic Structure) simulation program was used to simulate Amorphous Silicon p-i-n Solar Cell. The simulated result of illuminated current density-voltage characteristics was in a good agreement with experimental values. The dependence of the open-circuit voltage on the characteristics of the a-Si:H intrinsic layer was investigated. The simulation result shows that the open-circuit voltage does not depend on the thickness of the intrinsic layer. The open-circuit voltage decreases when the front contact barrier height is small or the energy gap of the intrinsic layer is small. The open-circuit voltage increases when the distribution of the tail states is sharp or the capture cross sections of these states are small.

Cu5,5P1,2Se5,0I1,3 thin film was deposited onto silicate glass substrate by nonreactive radio frequency magnetron sputtering. Structural studies were carried out using X-ray diffraction and SEM techniques. Spectrometric studies of transmission spectra of Cu5,5P1,2Se5,0I1,3 thin film in the temperature interval 77 to 300 К were investigated. It is shown that the temperature behaviour of optical absorption edge is described by the Urbach rule. Temperature dependences of optical parameters of the Urbach absorption edge and refractive index have been analyzed. The influence of temperature and structural disordering on the Urbach tail has been studied. The comparison of optical parameters of Cu6PSe5I crystal and Cu5,5P1,2Se5,0I1,3 thin film has been performed.

The overdamped Brownian motion of a self-propelled particle which is driven by a projected internal force is studied by solving the Langevin equation analytically. The "active" particle under study is restricted to move along a linear channel. The direction of its internal force is orientationally diffusing on a unit circle in a plane perpendicular to the substrate. An additional time-dependent torque is acting on the internal force orientation. The model is relevant for active particles like catalytically driven Janus particles and bacteria moving on a substrate. Analytical results for the first four time-dependent displacement moments are presented and analysed for several special situations. For a vanishing torque, there is a significant dynamical non-Gaussian behaviour at finite times t as signalled by a non-vanishing normalized kurtosis in the particle displacement which approaches zero for long time with a 1/t long-time tail.

It is shown that systemic injections of analgin and ketorolac in doses equivalent to those used in clinics induce antinociception in awake rats (tail-flick test) and, when carried out repetitively, induce tolerance to these agents and cross-tolerance to morphine (blocked by naloxone).

Лимонна вербена (ЛВ) використовується в традиційній народній медицині як засіб проти астми, спазмів, застуди, лихоманки, болю різного походження, безсоння і т. п., проте її ефекти не досліджувались експериментально. Вивчали дію водного екстракту листя цієї рослини на параметри тестів, пов'язаних із ноцицепцією, - тесту відсмикування хвоста та тесту "кислотних корчів". Готували перший водний екстракт із листя ЛВ та дегітратували його. Досліди було проведено на 7-ми експериментальних групах щурів лінії Вістар; тварини цих груп одержували внутрішньоочеревинні ін'єкції фізіологічного розчину (контроль), ЛВ-екстракту в 4-х дозах (10, 100, 500 та 1000 мг сухої речовини на 1 кг маси тіла), морфіну та екстракту ЛВ (1000 мг/кг) із попередньою ін'єкцією налоксону. Ін'єкції екстракту в дозах 500 та 1000 мг/кг призводили до суттєвого збільшення латентного періоду реакції відсмикування хвоста у порівнянні з аналогічним показником у контролі (P << 0,001). Кількість "корчів" у відповідному тесті протягом 1 год суттєво зменшувалася після ін'єкцій екстракту в дозах від 100 до 1000 мг/кг. Максимальні аналгетичні ефекти були близькими до таких після ін'єкцій морфіну (10 мг/кг). Налоксон повністю усував ефекти екстракту ЛВ у тесті відсмикування хвоста, але лише частково пригнічував відповідну дію в тесті "корчів". Отже, результати проведених експериментів показали, що водний екстракт листя ЛВ має відчутну антиноцицептивну дію; можливості застосування цього екстракту або його похідних у контролі болю мають бути досліджені в подальшому.