Glass capillary X-ray lens: fabrication technique and ray tracing calculations

A new method for producing a compound refractive X-ray lens is described. The lens is designed as glass capillary "lled by a set of concave individual lenses. The method is appropriate for the preparation of 10}1000 spherical lenses in a glass capillary with a diameter of 0.1}1 mm. Lens aberrations are considered and simple formulas for spot size are derived. Ray-tracing simulations on the focusing experiments using 18 keV X-rays are reported. ( 2000 Elsevier Science B.V. All rights reserved

Target mass number dependence of subthreshold antiproton production in proton-, deuteron- and alpha-particle-induced reactions

Data from KEK on subthreshold \bar{\mrm{p}} as well as on $\pi^\pm$ and \mrm{K}^\pm production in proton-, deuteron- and $\alpha$-induced reactions at energies between 2.0 and 12.0 A GeV for C, Cu and Pb targets are described within a unified approach. We use a model which considers a nuclear reaction as an incoherent sum over collisions of varying numbers of projectile and target nucleons. It samples complete events and thus allows for the simultaneous consideration of all final particles including the decay products of the nuclear residues. The enormous enhancement of the \bar{\mrm{p}} cross section, as well as the moderate increase of meson production in deuteron and $\alpha$ induced compared to proton-induced reactions, is well reproduced for all target nuclei. In our approach, the observed enhancement near the production threshold is mainly due to the contributions from the interactions of few-nucleon clusters by simultaneously considering fragmentation processes of the nuclear residues. The ability of the model to reproduce the target mass dependence may be considered as a further proof of the validity of the cluster concept.Comment: 9 pages, 4 figure

Oxidation Of Adenosine And Inosine: The Chemistry Of 8-oxo-7,8-dihydropurines, Purine Iminoquinones, And Purine Quinones As Observed By Ultrafast Spectroscopy

Oxidative damage to purine nucleic acid bases proceeds through quinoidal intermediates derived from their corresponding 8-oxo-7,8-dihydropurine bases. Oxidation studies of 8-oxo-7,8-dihyroadenosine and 8-oxo-7,8-dihydroinosine indicate that these quinoidal species can produce stable cross links with a wide variety of nucleophiles in the 2-positions of the purines. An azide precursor for the adenosine iminoquinone has been synthesized and applied in ultrafast transient absorption spectroscopic studies. Thus, the adenosine iminoquinone can be observed directly, and its susceptibility to nudeophilic attack with various nucleophiles as well as the stability of the resulting cross linked species have been evaluated Finally, these observations indicate that this azide might be a very useful photoaffurity labeling agent, because the reactive intermediate, adenosine iminoquinone, is such a good mimic for the universal purine base adenosine

ОСОБЕННОСТИ КЛИНИЧЕСКОГО ТЕЧЕНИЯ МЕТАСТАТИЧЕСКИХ И ПЕРВИЧНЫХ ОПУХОЛЕЙ ЯИЧНИКОВ ПРИ РАКЕ ТОЛСТОЙ КИШКИ

The aim of this study was to investigate clinical pecuiliarities of ovarian tumors in colon cancer patients and determination of complex diagnostic methods.Subject and methods. Russian N.N.  Blokhin Cancer Research Center archives were used for retrospective study, patients, who underwent treatment during 1989–2013  were included. Colon cancer patients with ovarian metastases and with synchronous or metachronous tumors were included.Results. 141 patients were included: 91 patients had colon cancer with ovarian metastases (group 1) and 50 patients had synchronous or metachronous ovarian tumours (group 2). Ovarian tumors were diagnosed during the 1 year in 74 (81.3 %) patients in group 1 and in 23 (46 %) in group 2. Patients in group 2 less frequently had children (9 (18.0 %) vs 5 (5.5 + 2.3 %), р < 0.05), family history of cancer (3 (6 %) vs 16 (17.6 %), р < 0.05) and concomitant diseases. Median CA 125 level in group 1 was 64.96 ng/ml and 180 ng/ml in group 2. Ovarian tumors had solid and cystic structure during US examination in 66 (73 %) patients in group 1 and 31 (62 %) patients in group 2 had solid ovarian tumors on US examination.Conclusions. The differential diagnostics of primary and metastatic ovarian tumors must include CEA, CA 19–9 and CA 125 serum levels and pelvic US.Цель исследования: изучение клинических особенностей опухолей яичников у больных раком толстой кишки (РТК) и определениероли комплексного подхода к их диагностике.Материалы и методы исследования. Материалом для исследования служил архив ФГБУ «РОНЦ им. Н.Н. Блохина»РАМН с 1989 по 2013 г. Включались больные РТК с метастазами в яичники или с синхронным или метахронным раком яичников. Результаты. В исследовании проанализирована 141 история болезни пациенток с установленным диагнозом РТК, из них 91 с ме- тастатическим поражением яичников (1-я группа) и 50 пациенток с первично-множественным поражением яичников при РТК (2-я группа). В течение первого года опухоли яичников диагностированы у 74 (81,3 %) пациенток в 1-й группе и у 23 (46 %) – во 2-й. Пациентки во 2-й группе достоверно чаще были нерожавшими (9 (18,0 %) против 5 (5,5 + 2,3 %), р < 0,05), реже имели семейный анамнез (3 (6 %) против 16 (17,6 %), р < 0,05) и сопутствующие заболевания. Медиана уровня маркера СА 125 соста- вила 64,96 нг/мл в 1-й группе против 180 нг/мл во 2-й группе. При ультразвуковом исследовании (УЗИ) метастазы в яичники чаще имели солидно-кистозную структуру – у 66 (73,3 %) пациенток, а первичные опухоли яичников – солидную – у 31 (62 %). Выводы. Для ранней диагностики поражения яичников в диагностический алгоритм необходимо включение определения уровня опухолевых маркеров РЭА, СА 19–9,  СА 125, УЗИ органов малого таза

Microspot x-ray focusing using a short focal-length compound refractive lenses

We have fabricated and tested short focal-length compound refractive lenses (CRLs) composed of microbubbles embedded in epoxy encased in glass capillaries. The interface between the bubbles formed 90 to 350 spherical biconcave microlenses reducing the overall focal length inversely by the number of lenses or bubbles. When compared with CRLs manufactured using other methods, the microbubble lenses have shorter focal lengths with higher transmissions and larger gains for moderate energy x rays (e.g., 7–20 keV). We used beamline 2–3 at the Stanford Synchrotron Radiation Laboratory and beamline 5BM-D-DND at the Advanced Photon Source to measure focal lengths between 100–250 mm with lens apertures varying between 97 and 321 mm. Transmission profiles were measured giving, for example, a peak transmission of 46% for a 240 mm focal length CRL at 20 keV. The focal-spot sizes were also measured yielding, for example, a vertical spot size of 1.2 mm resulting from an approximate 20-fold demagnification of the APS 23 mm source size. The measured gains in intensity over that of unfocused beam were between 9 and 26

The Ethnic 'Other' in Ukrainian History Textbooks: The Case of Russia and the Russians

This paper examines portrayals of Russia and the Russians in two generations of Ukrainian history textbooks. It observes that the textbooks are highly condemning of Ukraine's main ethnic other in the guise of foreign ruler: the tsarist authorities and the Soviet regime are always attributed dubious and malicious intentions even if there is appreciation for some of their policies. By contrast, the books, certainly those of the second generation, refrain from presenting highly biased accounts of the ethnic other as a national group (i.e. Russians). Instances where negative judgements do fall onto Russians are counterbalanced by excerpts criticizing ethnic Ukrainians or highlighting conflicting interests within the Ukrainian ethnic group. The negative appraisal of the ethnic other as foreign ruler is clearly instrumental for the nation-building project as it sustains a discourse legitimating the existence of Ukraine as independent state. However, recent trends in history education, the paper concludes, suggest that the importance of nurturing patriotism as a national policy objective is diminishing

Near-threshold production of omega mesons in the pn -> d omega reaction

The first measurement of the p n -> d omega total cross section has been achieved at mean excess energies of Q = 28 and 57 MeV by using a deuterium cluster-jet target. The momentum of the fast deuteron was measured in the ANKE spectrometer at COSY-Juelich and that of the slow "spectator" proton p(sp) from the p d -> p(sp) d omega reaction in a silicon telescope placed close to the target. The cross sections lie above those measured for p p -> p p omega but seem to be below theoretical predictions.Comment: 7 pages, 8 figures; second approach to describe the background has been added; results changed insignificantly, EPJ in pres

Subthreshold antiproton production in proton-carbon reactions

Data from KEK on subthreshold antiproton as well as on pi(+-) and K(+-) production in proton-nucleus reactions are described at projectile energies between 3.5 and 12.0 GeV. We use a model which considers a hadron-nucleus reaction as an incoherent sum over collisions of the projectile with a varying number of target nucleons. It samples complete events and allows thus for the simultaneous consideration of all particle species measured. The overall reproduction of the data is quite satisfactory. It is shown that the contributions from the interaction of the projectile with groups of several target nucleons are decisive for the description of subthreshold production. Since the collective features of subthreshold production become especially significant far below the threshold, the results are extrapolated down to COSY energies. It is concluded that an antiproton measurement at ANKE-COSY should be feasible, if the high background of other particles can be efficiently suppressed.Comment: 15 pages, 5 figures, gzipped tar file, submitted to J. Phys. G v2: Modification of text due to demands of referee

Resonant X-ray Scattering in Manganites - Study of Orbital Degree of Freedom -

Orbital degree of freedom of electrons and its interplay with spin, charge and lattice degrees of freedom are one of the central issues in colossal magnetoresistive manganites. The orbital degree of freedom has until recently remained hidden, since it does not couple directly to most of experimental probes. Development of synchrotron light sources has changed the situation; by the resonant x-ray scattering (RXS) technique the orbital ordering has successfully been observed . In this article, we review progress in the recent studies of RXS in manganites. We start with a detailed review of the RXS experiments applied to the orbital ordered manganites and other correlated electron systems. We derive the scattering cross section of RXS where the tensor character of the atomic scattering factor (ASF) with respect to the x-ray polarization is stressed. Microscopic mechanisms of the anisotropic tensor character of ASF is introduced and numerical results of ASF and the scattering intensity are presented. The azimuthal angle scan is a unique experimental method to identify RXS from the orbital degree of freedom. A theory of the azimuthal angle and polarization dependence of the RXS intensity is presented. The theoretical results show good agreement with the experiments in manganites. Apart from the microscopic description of ASF, a theoretical framework of RXS to relate directly to the 3d orbital is presented. The scattering cross section is represented by the correlation function of the pseudo-spin operator for the orbital degree of freedom. A theory is extended to the resonant inelastic x-ray scattering and methods to observe excitations of the orbital degree of freedom are proposed.Comment: 47 pages, 24 figures, submitted to Rep. Prog. Phy