High precision studies of soft dipole mode in two-neutron halo nuclei: 6^{6}He case

The "soft dipole" E1 strength function is calculated for the transition from the $^{6}$He $0^+$ ground state to the $1^-$ continuum $^{4}$He+$n$+$n$. The calculations were performed within the hyperspherical harmonics formalism. The sensitivity of the results to the $^{6}$He ground state structure and to final state interactions, are analyzed. The large-basis calculations show the reliably converged results for soft dipole strength function and for momentum correlations of the ^{6}\mbox{He} \rightarrow \, ^{4}He+$n$+$n$ dissociation products. Transition mechanisms are analyzed based on the momentum correlations. The comparison with experimental data is provided.Comment: 16 pages, 17 figure

From Coulomb excitation cross sections to non-resonant astrophysical rates in three-body systems: 17^{17}Ne case

Coulomb and nuclear dissociation of $^{17}$Ne on light and heavy targets are studied theoretically. The dipole E1 strength function is determined in a broad energy range including energies of astrophysical interest. Dependence of the strength function on different parameters of the $^{17}$Ne ground state structure and continuum dynamics is analyzed in a three-body model. The discovered dependence plays an important role for studies of the strength functions for the three-body E1 dissociation and radiative capture. The constraints on the $[s^2]/[d^2]$ configuration mixing in $^{17}$Ne and on $p$-wave interaction in the $^{15}$O+$p$ channel are imposed based on experimental data for $^{17}$Ne Coulomb dissociation on heavy target.Comment: 12 pages, 13 figure

Asymptotic normalization coefficient method for two-proton radiative capture

The method of asymptotic normalization coefficients is a standard approach for studies of two-body non-resonant radiative capture processes in nuclear astrophysics. This method suggests a fully analytical description of the radiative capture cross section in the low-energy region of the astrophysical interest. We demonstrate how this method can be generalized to the case of three-body $2p$ radiative captures. It was found that an essential feature of this process is the highly correlated nature of the capture. This reflects the complexity of three-body Coulomb continuum problem. Radiative capture $^{15}$O+$p$+$p \rightarrow ^{\,17}$Ne+$\gamma$ is considered as an illustration.Comment: 9 pages, 8 figure

Superhalo of C 22 reexamined

An unusually large value of the C22 matter radius, extracted by Tanaka et al. [Phys. Rev. Lett. 104, 062701 (2010)PRLTAO0031-900710.1103/PhysRevLett.104.062701] from measured reaction cross sections, attracted great attention of scientific community. Since that time, several experimental works related to the C22 nucleus have appeared in the literature. Some of the experimental data, measured with high accuracy, allow us to fix C22 structure more reliably. Two limiting models reproducing C22 nuclear structure within the three-body cluster approach, that allow us to describe all existing experimental data, are presented. The C22 ground state, continuum structure, and geometry are obtained. With fixed C22 wave function, the prediction for the soft dipole mode in C22, which is studied in the process of Coulomb fragmentation, is performed

Halo Excitation of 6^6He in Inelastic and Charge-Exchange Reactions

Four-body distorted wave theory appropriate for nucleon-nucleus reactions leading to 3-body continuum excitations of two-neutron Borromean halo nuclei is developed. The peculiarities of the halo bound state and 3-body continuum are fully taken into account by using the method of hyperspherical harmonics. The procedure is applied for A=6 test-bench nuclei; thus we report detailed studies of inclusive cross sections for inelastic $^6$He(p,p')$^6$He$^*$ and charge-exchange $^6$Li(n,p)$^6$He$^*$ reactions at nucleon energy 50 MeV. The theoretical low-energy spectra exhibit two resonance-like structures. The first (narrow) is the excitation of the well-known $2^+$ three-body resonance. The second (broad) bump is a composition of overlapping soft modes of multipolarities $1^-, 2^+, 1^+, 0^+$ whose relative weights depend on transferred momentum and reaction type. Inelastic scattering is the most selective tool for studying the soft dipole excitation mode.Comment: Submitted to Phys. Rev. C., 11 figures using eps

Local cytokine levels as prognostic factors for early relapse of non-muscle-invasive bladder carcinoma

The aim of our study is to assess the local cytokine levels as prognostic factors for early relapse in NMIBC patients. 75 patients with NMIBC were enrolled in the study: 51 with primary NMIBC and 24 with initially recurrent NMIBC, LG and HG tumors were diagnosed in each group. Patients with primary NMIBC were monitored during 9 months after treatment: TURB and chemotherapy (No. 6). During TURB samples of tumors were taken, supernatants were obtained and tissue cytokine levels were measured (IL-1β, IL-6, IL-10, IL-18, TNFα, IFNγ, IL-8) by ELISA test. The results showed that in patients with primary NMIBC early relapses were diagnosed in 15 (46.8%) of LG tumors and in 11 (45%) of HG tumors matching that there was no difference depending upon tumor grade. In initially recurrent tumors of both LG and HG NMIBC the amounts of cytokines were maximal: in LG tumors they exceeded the primary ones from 7.1 (IFNγ) to 300 (IL-6) while in HG - from 2.0 (IL-10) to 9.7 (IL-6). The amounts of IL-1β, IL-6, IL-10, IFNγ, IL-8 were higher in those LG primary tumors which relapsed in 6-9 months compared to the ones which didn't, though their levels were much lower than in initially manifested relapse (from 2.6 times for IFNy to 150 times for IL-6). A similar trend, though not for all the same cytokines, was observed in HG tumors: tissue levels of IL-6, IL-10, IL-18 and TNFα were higher in tumors which relapsed in 6-9 months after treatment. The increase of 2 cytokines' levels were common for both LG and HG tumors (IL-6 and IL-10). This finding might be considered as a new prognostic factor of the early relapse. We conclude that relapse of LG and HG NMIBC is related to some immune mechanisms, namely to local hyperproduction of cytokines, especially IL-6 and IL-10, though IL-1β, IL-8, IFNγ could have an impact on LG and IL-18, TNFα — on HG tumors. Taking into account common signaling pathways of IL-6 and IL-10 like JAK/STAT, these transcription factors might be potential targets for new effective approaches to treatment

The 6^{6}H states studied in the d(8He,α)d(^8\text{He},\alpha) reaction and evidence of extremely correlated character of the 5^{5}H ground state

The extremely neutron-rich system $^{6}$H was studied in the direct $^2\text{H}(^8\text{He},{^4\text{He}})^{6}$H transfer reaction with a 26 $A$ MeV secondary $^{8}$He beam. The measured missing mass spectrum shows a resonant state in $^{6}$H at $6.8(3)$ MeV relative to the $^3$H+$3n$ threshold. The population cross section of the presumably $p$-wave states in the energy range from 4 to 8 MeV is $d\sigma/d\Omega_{\text{c.m.}} \simeq 190(40)$ $\mu$b/sr in the angular range $5^{\circ}<\theta_{\text{c.m.}}<16^{\circ}$. The obtained missing mass spectrum is free of the $^{6}$H events below 3.5 MeV ($d\sigma/d\Omega_{\text{c.m.}} \lesssim 3$ $\mu$b/sr in the same angular range). The steep rise of the $^{6}$H missing mass spectrum at 3 MeV allows to show that $4.5(3)$ MeV is the lower limit for the possible resonant state energy in $^{6}$H tolerated by our data. According to paring energy estimates, such a $4.5(3)$ MeV resonance is a realistic candidate for the $^{6}$H ground state (g.s.). The obtained results confirm that the decay mechanism of the $^{7}$H g.s.\ (located at 2.2 MeV above the $^{3}$H+$4n$ threshold) is the ``true'' (or simultaneous) $4n$ emission. The resonance energy profiles and the momentum distributions of the sequential $^{6}$H \,\rightarrow \, ^5H(g.s.)+n\, \rightarrow \, ^3H+$3n$ decay fragments were analyzed by the theoretically-updated direct four-body-decay and sequential-emission mechanisms. The measured momentum distributions of the $^{3}$H fragments in the $^{6}$H rest frame indicate very strong ``dineutron-type'' correlations in the $^{5}$H ground state decay.Comment: 9 pages, 11 figure

Expression of some molecular and biological markers in esophageal tumors of various stages and grades

Objectives: immunohistochemical study of the expression of molecular and biological markers (p53, bcl-2 and ki-67) in esophageal tumors of various stages and grades, and evaluation of the markers in the disease prognosis. Material and methods: the study included 30 patients of a retrospective group with stage II-III squamous cell carcinoma of the esophagus. Immunohistochemical study of paraffi n sections was performed using primary mouse monoclonal antibodies against p53, bcl-2 and ki67, and Reveal Polyvalent HRP-DAB Detection System. Results: diff erences in the rates and expression of molecular and biological markers (p53, bcl-2 and ki-67), controlling apoptosis and proliferation, depended on the tumor stage and grade. Conclusions: fdvanced cancer of the esophagus demonstrated an increase in rates and expression of p53+ and ki-67, as well as in the proliferative activity of tumor cells. Bcl-2 expression was more frequent and intensive in stage II tumors, compared to stage III. Esophageal tumors of higher grades were characterized with higher rates and expression of p53 and ki-67, and conversely for the bcl-2 expression. Th e revealed diff erences can be used in the disease prognosis

Ecto-5′-nucleotidase and intestinal ion secretion by enteropathogenic Escherichia coli

Enteropathogenic Escherichia coli (EPEC) triggers a large release of adenosine triphosphate (ATP) from host intestinal cells and the extracellular ATP is broken down to adenosine diphosphate (ADP), AMP, and adenosine. Adenosine is a potent secretagogue in the small and large intestine. We suspected that ecto-5′-nucleotidase (CD73, an intestinal enzyme) was a critical enzyme involved in the conversion of AMP to adenosine and in the pathogenesis of EPEC diarrhea. We developed a nonradioactive method for measuring ecto-5′-nucleotidase in cultured T84 cell monolayers based on the detection of phosphate release from 5′-AMP. EPEC infection triggered a release of ecto-5′-nucleotidase from the cell surface into the supernatant medium. EPEC-induced 5′-nucleotidase release was not correlated with host cell death but instead with activation of phosphatidylinositol-specific phospholipase C (PI-PLC). Ecto-5′-nucleotidase was susceptible to inhibition by zinc acetate and by α,β-methylene-adenosine diphosphate (α,β-methylene-ADP). In the Ussing chamber, these inhibitors could reverse the chloride secretory responses triggered by 5′-AMP. In addition, α,β-methylene-ADP and zinc blocked the ability of 5′-AMP to stimulate EPEC growth under nutrient-limited conditions in vitro. Ecto-5′-nucleotidase appears to be the major enzyme responsible for generation of adenosine from adenine nucleotides in the T84 cell line, and inhibitors of ecto-5′-nucleotidase, such as α,β-methylene-ADP and zinc, might be useful for treatment of the watery diarrhea produced by EPEC infection