522 research outputs found
Optical-electronic System and Software Complex for Research and Identification of Macro- and Micro-optical Elements of Security Holograms
The paper presents an automated optical-electronic software and hardware complex for carrying out activities to identify and control the authenticity of diffraction and holographic optical security elements. The developed complex makes it possible to significantly simplify the work of the expert in conducting forensic studies of objects marked with security holograms
Review of the some specific features of the detecting of heavy recoils
In this paper, we present the results of the first beam tests of the
detection system at the focal plane of the Dubna Gas-Filled Recoil Separator-2
(DGFRS-2), which receives beams from the DC-280 FLNR cyclotron. The high beam
intensity of Ca heavy ions from the cyclotron enables us to
obtain a number of superheavy recoils sufficient to compare both the measured
and calculated spectra of superheavy recoils implanted into a silicon detector.
A real-time algorithm to search for an Evaporation Residue (ER) --
correlated sequences is described in brief. It should be noted that the DGFRS-2
spectrometer operates in conjunction with the 48x128 strip DSSD (Double-sided
Silicon Strip Detector; 48x226 mm2) detector and a low-pressure pentane-filled
gaseous detector (1.2 Torr; 80x230 mm). A block-diagram of the spectrometer
and the event format are also presented. Special attention is paid to the
response of a low-pressure pentane-filled DeltaE multiwire proportional chamber
for recoils of Fl, synthesized in the Pu+Ca Fl +3n
complete fusion nuclear reaction. Some actual parameters of the detection
system have also been extracted from Yb + Ca, Th +
Ca, Am + Ca, U + Ca reactions. The effect
of neighbor strip charge sharing for the ohmic side of the DSSD detector is
also under consideration.Comment: 18 page
Composite implants coated with biodegradable polymers prevent stimulating tumor progression
In this experiment we studied oncologic safety of model implants created using the solution blow spinning method with the use of the PURASORB PL-38 polylactic acid polymer and organic mineral filler which was obtained via laser ablation of a solid target made of dibasic calcium phosphate dihydrate. For this purpose the implant was introduced into the area of Wistar rats’ iliums, and on day 17 after the surgery the Walker sarcoma was transplanted into the area of the implant. We evaluated the implant’s influence on the primary tumor growth, hematogenous and lymphogenous metastasis of the Walker sarcoma. In comparison with sham operated animals the implant group demonstrated significant inhibition of hematogenous metastasis on day 34 after the surgery. The metastasis inhibition index (MII) equaled 94% and the metastases growth inhibition index (MGII) equaled 83%. The metastasis frequency of the Walker sarcoma in para aortic lymph nodes in the implant group was not statistically different from the control frequency; there was also no influence of the implant on the primary tumor growth noted. In case of the Walker sarcoma transplantation into the calf and the palmar pad of the ipsilateral limb to the one with the implant in the ilium, we could not note any attraction of tumor cells to the implant area, i.e. stimulation of the Walker sarcoma relapse by the implant. Thus, the research concluded that the studied implant meets the requirements of oncologic safety
Composite implants coated with biodegradable polymers prevent stimulating tumor progression
In this experiment we studied oncologic safety of model implants created using the solution blow spinning method with the use of the PURASORB PL-38 polylactic acid polymer and organic mineral filler which was obtained via laser ablation of a solid target made of dibasic calcium phosphate dihydrate. For this purpose the implant was introduced into the area of Wistar rats’ iliums, and on day 17 after the surgery the Walker sarcoma was transplanted into the area of the implant. We evaluated the implant’s influence on the primary tumor growth, hematogenous and lymphogenous metastasis of the Walker sarcoma. In comparison with sham operated animals the implant group demonstrated significant inhibition of hematogenous metastasis on day 34 after the surgery. The metastasis inhibition index (MII) equaled 94% and the metastases growth inhibition index (MGII) equaled 83%. The metastasis frequency of the Walker sarcoma in para aortic lymph nodes in the implant group was not statistically different from the control frequency; there was also no influence of the implant on the primary tumor growth noted. In case of the Walker sarcoma transplantation into the calf and the palmar pad of the ipsilateral limb to the one with the implant in the ilium, we could not note any attraction of tumor cells to the implant area, i.e. stimulation of the Walker sarcoma relapse by the implant. Thus, the research concluded that the studied implant meets the requirements of oncologic safety
Spontaneous periodic travelling waves in oscillatory systems with cross-diffusion
We identify a new type of pattern formation in spatially distributed active
systems. We simulate one-dimensional two-component systems with predator-prey
local interaction and pursuit-evasion taxis between the components. In a
sufficiently large domain, spatially uniform oscillations in such systems are
unstable with respect to small perturbations. This instability, through a
transient regime appearing as spontanous focal sources, leads to establishment
of periodic traveling waves. The traveling waves regime is established even if
boundary conditions do not favor such solutions. The stable wavelength are
within a range bounded both from above and from below, and this range does not
coincide with instability bands of the spatially uniform oscillations.Comment: 7 pages, 4 figures, as accepted to Phys Rev E 2009/10/2
Tevatron Beam Halo Collimation System: Design, Operational Experience and New Methods
Collimation of proton and antiproton beams in the Tevatron collider is
required to protect CDF and D0 detectors and minimize their background rates,
to keep irradiation of superconducting magnets under control, to maintain
long-term operational reliability, and to reduce the impact of beam-induced
radiation on the environment. In this article we briefly describe the design,
practical implementation and performance of the collider collimation system,
methods to control transverse and longitudinal beam halo and two novel
collimation techniques tested in the Tevatron.Comment: 25 p
Предиктивная и прогностическая значимость явления потери гетерозиготности в генах ABC-транспортеров в опухоли молочной железы
ABC-transporter family genes have been well studied and their involvement in the development of drug resistance has been assessed. The presence of aberrant conditions in these genes can affect the treatment and prognosis of the disease. Loss of heterozygosity (LOH) is one of these conditions; it is a common event in cancer development. Therefore, the aim of this study was to investigate the relationship between LOH in ABC transporter genes in breast cancer and response to chemotherapy and disease prognosis. Material and Methods. A total of 130 breast cancer patients were included in the study. Microarray analysis was performed on Affymetrix CytoScan™ HD Array high-density DNA chips to assess LOH status. Chromosome Analysis Suite 4.1 software (Affymetrix, USA) was used to process microarray results. Results. Forty-nine ABC transporter genes were evaluated for LOH. The frequency of LOH ranged from 6.9 % to 90 %. An association analysis identified two genes: ABCG5 and ABCG8, in which the presence of LOH was associated with a lack of objective response to neoadjuvant chemotherapy. The presence of LOH in the ABCA5, ABCA6, ABCA8, ABCA9, ABCA10 and ABCC3 genes was associated with high rates of metastasis-free survival (log-rank test, p<0.04). conclusion. The presence of loss of heterozygosity in the ABC transporter genes was found to have no significant effect on the response to chemotherapy. However, a high prognostic potential of ABCA family genes was found
The influence of the dechanneling process on the photon emission by an ultra-relativistc positron channeling in a periodically bent crystal
We investigate, both analytically and numerically, the influence of the
dechanneling process on the parameters of undulator radiation generated by
ultra-relativistic positron channelling along a crystal plane, which is
periodically bent. The bending might be due either to the propagation of a
transverse acoustic wave through the crystal, or due to the static strain as it
occurs in superlattices. In either case the periodically bent crystal serves as
an undulator which allows to generate X-ray and gamma-radiation.
We propose the scheme for accurate quantitative treatment of the radiation in
presence of the dechanneling. The scheme includes (i) the analytic expression
for spectral-angular distribution which contains, as a parameter, the
dechanneling length, (ii) the simulation procedure of the dechanneling process
of a positron in periodically bent crystals. Using these we calculate the
dechanneling lengths of 5 GeV positrons channeling in Si, Ge and W crystals,
and the spectral-angular and spectral distributions of the undulator over broad
ranges of the photons. The calculations are performed for various parameters of
the channel bending.Comment: published in J. Phys. G: Nucl. Part. Phys. 27 (2001) 95-125,
http://www.iop.or
Опыт обоснования изменения коэффициента возраста и стажа водителя в ОСАГО
The article highlights the influence of the equity factor in the insurance industry on the example of the age and driving experience coefficient development in the motor third-party liability insurance (MTPL). The aim of the research is to study risk level variation in the car insurance industry depending on the age and experience of a driver. The authors consider the Automated Information System (AIS) data of MTPL as a methodological basis of the article. The results show that the risk level depends on each of the parameters, in particular, risk levels for older drivers are lower by comparison with younger drivers with the same level of driving experience. On this basis, the authors design a two-dimensional table to assess risk levels where the risk level between separate cells differ in five times. The study presents and analyses the actuarial calculations which served as a foundation for the MTPL policy change in 2018* 1. The article provides recommendations on improving MTPL tariffing within the modern model framework and motor tariff liberalization. The study allowed the authors to verify theoretical assumptions and find direct mathematical relations between the age and experience coefficient and its constituent data. The authors concluded that it is reasonable to introduce additional categories of drivers taking into consideration demographic changes and retirement age increase. The results of the research may improve MTPL affordability and have practical utility for motor insurers in transition to individual tariffs. They also can help to address discussions and approaches to estimate a coefficient of age and experience (CAE) set by Article 9 of the Federal law of 25.04.2002 No. 40-FZ “About obligatory insurance of civil liability of owners of vehicles”.Авторы рассматривают влияние фактора справедливости на страховые отношения на примере развития коэффициента возраст/стаж в обязательном страховании гражданской ответственности автовладельцев (ОСАГО). Цель работы - исследование изменения уровня риска в автостраховании в зависимости от возраста и стажа водителя. Методологической основой исследования стал анализ первичных данных по договорам и убыткам ОСАГО, полученных из базы данных автоматизированной информационной системы обязательного страхования автогражданской ответственности (АИС ОСАГО). В результате установлено, что уровень риска зависит от каждого из параметров. В частности, водители более старшего возраста при одинаковом опыте вождения с молодыми водителями будут формировать меньший уровень риска. Это позволяет построить двумерную таблицу оценки уровня риска, где его значение между отдельными ячейками будет отличаться более, чем в пять раз. Представлены и проанализированы актуарные расчеты, положенные в основу изменения практики тарификации ОСАГО в 2018 г.* Даны рекомендации по совершенствованию тарификации ОСАГО в рамках современной модели и в случае либерализации страховых тарифов. Проведенное исследование позволило проверить теоретические предположения и выявило наличие прямых математических закономерностей коэффициента возраст-стаж от составляющих его данных. Сделан вывод, что существует возможность и целесообразность введения дополнительных категорий водителей с учетом изменения демографической ситуации и повышения пенсионного возраста. Результаты исследования могут быть применены в целях повышения ценовой доступности полисов ОСАГО в рамках практической деятельности автостраховщиков при переходе к индивидуальным тарифам, а также могут использоваться в рамках обсуждения предложений по реформе подходов к расчету коэффициента возраст-стаж (КВС), установленного ст. 9 Федерального закона от 25.04.2002 № 40-ФЗ «Об обязательном страховании гражданской ответственности владельцев транспортных средств»
One-dimensional Model of a Gamma Klystron
A new scheme for amplification of coherent gamma rays is proposed. The key
elements are crystalline undulators - single crystals with periodically bent
crystallographic planes exposed to a high energy beam of charged particles
undergoing channeling inside the crystals. The scheme consists of two such
crystals separated by a vacuum gap. The beam passes the crystals successively.
The particles perform undulator motion inside the crystals following the
periodic shape of the crystallographic planes. Gamma rays passing the crystals
parallel to the beam get amplified due to interaction with the particles inside
the crystals. The term `gamma klystron' is proposed for the scheme because its
operational principles are similar to those of the optical klystron. A more
simple one-crystal scheme is considered as well for the sake of comparison. It
is shown that the gamma ray amplification in the klystron scheme can be reached
at considerably lower particle densities than in the one-crystal scheme,
provided that the gap between the crystals is sufficiently large.Comment: RevTeX4, 22 pages, 4 figure
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