3D Structure of the Tail Complex of E. coli Bacteriophage DT57C

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Assessment of the possibility for large-scale 238Pu production in a VVER-1000 power reactor

The paper presents the estimates for the possibility for large-scale production of 238Pu in the core of a VVER-1000 power reactor. The Np-fraction of minor actinides extracted from transuranic radioactive waste is proposed to be used as the starting material. The irradiation device with NpO2 fuel elements is installed at the reactor core center. The NpO2 fuel lattice pitch is varied and the irradiation device is surrounded by a heavy moderator layer to create the best possible spectral conditions for large-scale production (~ 3 kg/year) of conditioned plutonium with the required isotopic composition (not less than 85% of 238Pu and not more than 2 ppm of 236Pu). Plutonium with such isotopic composition can be used as the thermal source in thermoelectric radioisotope generators and in cardiac pacemakers. It has been demonstrated that the estimated scale of the 238Pu production in a VVER-type power reactor exceeds considerably the existing scale of its production in research reactors

The ACTN3 R577X Polymorphism across Three Groups of Elite Male European Athletes

The ACTN3 R577X polymorphism (rs1815739) is a strong candidate to influence elite athletic performance. Yet, controversy exists in the literature owing to between-studies differences in the ethnic background and sample size of the cohorts, the latter being usually low, which makes comparisons difficult. In this case:control genetic study we determined the association between elite athletic status and the ACTN3 R577X polymorphism within three cohorts of European Caucasian men, i.e. Spanish, Polish and Russian [633 cases (278 elite endurance and 355 power athletes), and 808 non-athletic controls]. The odds ratio (OR) of a power athlete harbouring the XX versus the RR genotype compared with sedentary controls was 0.54 [95% confidence interval (CI): 0.34–0.48; P = 0.006]. We also observed that the OR of an endurance athlete having the XX versus the RR genotype compared with power athletes was 1.88 (95%CI: 1.07–3.31; P = 0.028). In endurance athletes, the OR of a “world-class” competitor having the XX genotype versus the RR+RX genotype was 3.74 (95%CI: 1.08–12.94; P = 0.038) compared with those of a lower (“national”) competition level. No association (P>0.1) was noted between the ACTN3 R577X polymorphism and competition level (world-class versus national-level) in power athletes. Our data provide comprehensive support for the influence of the ACTN3 R577X polymorphism on elite athletic performance

Nano-liposome of thyme essential oil promotes growth performance, antioxidant and immune responses to aeromonad septicemia in Nile tilapia, Oreochromis niloticus, fingerlings

Nano-encapsulation protects essential oils and increases their efficiency, compared to bulk forms. Hence in the present study, four diets (328 g/kg crude protein and 4402 kcal/kg gross energy) containing 0 (CTL), 25 mg/kg (25TV), 50 mg/kg (50TV), and 100 mg/kg (100TV) thyme, Thymus vulgaris, essential oil nano-liposomes (TV-NP) were offered to Nile tilapia fingerlings (initial weight of 4.27 ± 0.05 g) at water temperature of 26.46 ± 0.43°C, followed by intraperitoneal infection by Aeromonas hydrophila. Three hundred and sixty healthy fish were stocked in 12 tanks (60 L), 30 fish per tank, with daily water renewal rate of 40%. Each diet was offered to three tanks for 70 days. The fish were sampled at the end of feeding period and 12 h after the bacterial challenge. Compared to CTL, 50TV and 100TV treatments exhibited significant elevations in growth rate (14-17%; P<0.001), intestinal activities of amylase (9-19%; P=0.004), lipase (13-26%; P<0.001), protease (20-23%; P=0.001), and post-challenge survival (26-27%; P=0.001). Plasma lysozyme (14-15% P<0.001) and complement (5.1-5.4%; P=0.004) activities significantly increased in 25TV and 50TV, but decreased (lysozyme: 19%, complement 5.9%) in 100TV before the challenge; however, all TV-NP treatments showed similar lysozyme and complement activities after the challenge that were higher than CTL. 50TV and 100TV treatments also showed a decrease in lipid peroxidation (23-26%; P<0.001) and highest glutathione peroxidase activity (17-18%; P=0.001) and pre-challenge superoxide dismutase (21%; P=0.046) and catalase (15-17%; P=0.001) activities. Expression of tumor necrosis factor-alpha (11-fold, P<0.001), inerleukin-1 beta (5-fold, P<0.001), and transforming growth factor-beta (31-fold; P=0.001) in head kidney significantly increased in 100TV before the challenge. After the challenge, the transcripts of the cytokines significantly increased in all treatments and the highest expressions were observed in 50TV and 100TV treatments (62-148-fold). In conclusion, dietary 50-100 mg/kg TV-NP can be considered as a new feed additive in tilapia culture, as it improves growth rate, antioxidant capacity, and disease resistance in the fish

Роль компонентов микробиоты в модификации иммунного ответа при отдельных вариантах течения хронической обструктивной болезни легких

Background. According to the World Health Organization, chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality in the world. COPD with frequent exacerbations is a most challenging variant of the disease. Currently it is not clear how respiratory microbiota can modify the immune response in this disease.Aim. To establish the role of bacterial oligonucleotides in modification of the immune response in patients with COPD.Materials and мethods. In accordance with the protocol of the study, 10 patients with stable COPD with frequent exacerbations and 10 patients without frequent exacerbations were included. Immature dendritic cells were obtained by culturing the monocyte fraction of the peripheral blood of patients with COPD. The cells were stimulated by addition of bacterial lipopolysaccharide and small oligodeoxynucleotides (CpG-ODN) of A or B classes. Then the immunophenotypical profile of the obtained cells was determined by flow-cytometry with the use of monoclonal antibodies to antigens CD40, CD83, CD86. To determine the antigen-presenting properties, these dendritic cells were cultivated with CD4+, and then the phenotypic profile of the obtained T-lymphocytes was evaluated by using antibodies to CD4, CD25, CD127, and CD45RO.Results. Cultivation of stimulated dendritic cells by СpG-ODN of A class with T-cells in COPD patients without exacerbations leads to an increase of the amount of lymphocytes of CD25+CD45RO phenotype (15% increase after stimulation), in contrast to the group of patients with frequent exacerbations of COPD (p = 0,018). It may indicate inadequate control of persistent inflammation, mediated by CD25+CD45RO pool of cells in the group of COPD patients with frequent exacerbations.Conclusion. This study demonstrated the presence of discoordination of the immune response of a bidirectional nature in patients with COPD with frequent and infrequent exacerbations. По данным Всемирной организации здравоохранения, хроническая обструктивная болезнь легких (ХОБЛ) является одной из ведущих причин заболеваемости и смертности в мире. Неблагоприятным вариантом течения болезни, с точки зрения прогноза, является ХОБЛ с частыми обострениями. В настоящее время недостаточно изучен вклад компонентов микробиоты на изменение иммунного ответа при данной болезни.Цель работы. Установить роль компонентов бактерий – бактериальных олигонуклеотидов в модификации иммунного ответа при ХОБЛ.Материал и методы. В соответствии с протоколом в исследование включены 10 пациентов со стабильной ХОБЛ с частыми обострениями и 10 пациентов без частых обострений. Незрелые дендритные клетки, полученные при культивировании моноцитарной фракции периферической крови больных ХОБЛ, стимулировали путем добавления бактериального липополисахарида, а также малых олигодеоксинуклеотидов (ODN) с неметилированными CpG (CpG-ODN) классов А или В, после чего определяли иммунофенотипический профиль полученных клеток методом проточной цитофлуориметрии с использованием моноклональных антител к антигенам CD40, CD83, CD86. Для определения антиген-представляющих свойств полученных дендритных клеток их сокультивировали с CD4+, после чего оценивали фенотипический профиль полученных Т-лимфоцитов с использованием антител к CD4, CD25, CD127 и CD45RO.Результаты. Сокультивирование стимулированных СpG-ODN класса А-дендритных клеток с Т-клетками у больных ХОБЛ без обострений приводит к увеличению содержания лимфоцитов с фенотипом CD25+CD45RO- на 15% после стимуляции в отличие от группы пациентов с частыми обострениями ХОБЛ (р = 0,018). Это может свидетельствовать о недостаточном контроле над персистирующим воспалением, опосредованным CD25+CD45RO-пулом клеток, в группе больных ХОБЛ с частыми обострениями.Выводы и заключение. Проведенное исследование продемонстрировало наличие дискоординации иммунного ответа разнонаправленного характера при ХОБЛ с частыми и редкими обострениями, что может быть основой развития варианта течения ХОБЛ с частыми обострениями.

Половое развитие подростков в Томской области

Background. Sexual development of adolescents is one of the important indicators of the population well-being, the study of which, in the context of the world trend towards a change in the period of puberty, can contribute to the identification of public health problems. Objective. Our aim was to study the basic indicators of sexual development of adolescents and to determine the regional characteristics of this population. Methods. The evaluation of secondary sexual characteristics was carried out by specialists according to Tanner criteria. Ultrasound examination of organs of the reproductive system was carried out using a portable scanner Mindray M7. The analysis of the results was carried out taking into account the gender, living conditions, physical development. Results. We examined 7,120 adolescents aged from 13 to 16 years. The degree of axillary hair distribution by Tanner criteria was 2.4±0.7 in young men, 2.9±0.4 — in girls, pubic hair — 2.0±0.9 and 2.6±0.8, respectively. The indicator of development of mammary glands by Tanner criteria in girls was 2.6±0.8, menstrual function by Tanner criteria — 2.4±0.8. Herewith, urban adolescents had later terms of appearance of the secondary sexual characteristics in comparison with the inhabitants of rural areas. Conclusion. We registered the delayed sexual development in 8.1% of girls and 13.6% of young men. Urban youths have experienced a delay in gonadal growth. Among the female population there was an outstripping growth and development of the uterus and ovaries in comparison with rural adolescents. Половое развитие подростков — один из важных показателей благополучия населения, изучение которого в условиях мировой тенденции к изменению сроков наступления пубертатного периода может способствовать выявлению проблем общественного здравоохранения. Цель исследования — изучить основные показатели полового развития подростков и определить региональные особенности данной популяции. Методы. Оценка вторичных половых признаков проводилась врачами-специалистами по критериям Tanner. Ультразвуковое исследование органов репродуктивной системы осуществлялось при помощи переносного сканера Mindray M7. Анализ результатов проводили с учетом пола, условий проживания, физического развития. Результаты. Обследовано 7120 подростков в возрасте от 13 до 16 лет. Степень оволосения подмышечной впадины по критериям Tanner составила у юношей 2,4±0,7, у девушек — 2,9±0,4, степень лобкового оволосения — 2,0±0,9 и 2,6±0,8 соответственно. Показатель развития молочных желез по критериям Tanner у девушек составил 2,6±0,8, менструальная функция по критериям Tanner — 2,4±0,8. При этом у городских подростков выявлены более поздние сроки появления вторичных половых признаков в сравнении с жителями сельских районов. Заключение. У 8,1% девушек и 13,6% юношей зарегистрирована задержка полового развития. У городских юношей выявлена задержка роста гонад; среди женского населения наблюдалось опережение роста и развития матки и яичников в сравнении с сельскими подростками.

Proliferation protection of uranium due to the presence of U-232 decay products as intense sources of hard gamma radiation

The objectives of the article are (1) to show the nuclear and physical causes of hard γ-quanta in the U-232 decay chain, (2) to propose tactics for handling uranium containing U-232, and (3) to assess the efficiency of its protective γ-barrier against uncontrolled proliferation. The authors show the general picture of the decay chains of U-232 nuclide transformations, on which the protection of uranium from its uncontrolled proliferation is based. During the decay of nuclei, their emission of α- or β-particles is only the first stage of the most complex process of rearrangement of both the internal structure of the nucleus itself, which consists in the rearrangement of the neutron and proton shells and the levels of its excitation, and in the rearrangement of the electron shells of the atom. As a rule, the daughter nucleus is in a highly excited state, which is removed by the emission of hard γ-quanta and internal conversion electrons. After the second case, the remaining excitation of the atom is removed by the emission of characteristic γ-quanta and Auger-electrons with characteristic γ-quanta. In addition, explanations are given for the quantum-mechanical reasons for the hard γ-radiation of Tl-208 and Bi-212, which complete the U-232 decay chain. The authors also proposed a tactic for handling uranium containing uranium-232. Since the hard γ-quanta of Tl-208 and Bi-212 appear only at the end of the U-232 decay chain, after its chemical purification from its decay products, U-232 itself does not pose a radiation hazard; therefore, at this time it is advisable to conduct all necessary operations for transporting the material to the plant, fabricating uranium-based fuel containing U-232, and transporting this fuel to the nuclear facility where it will be used

Comprehensive analysis of proliferation protection of uranium due to the presence of 232U and its decay products

For a comprehensive assessment of the protection of uranium against proliferation due to the presence of uranium-232 in it, the authors of the article propose and substantiate an integral protection criterion for this material. The criterion is based on the physical barriers against the proliferation of uranium created by uranium-232, namely: (1) the radiolysis of uranium hexafluoride, which hinders attempts to re-enrich uranium and, as a result, a significant critical mass; (2) hard γ-radiation, which leads to incapacity and death of those who try to handle this material without radiation protection; (3) increased heat release, which disables the components of a nuclear explosive device; and (4) a significant source of neutrons that causes predetonation and thereby reduces the energy yield of a nuclear explosive device. These barriers appear at various stages of uranium handling not only in the indicated order but also act simultaneously, mutually reinforcing one another

Application of small perturbation theory for assessing variations of prompt neutron lifetime in a lead-cooled fast reactor

The paper considers the applicability of small perturbation theory to assessing the variations of the prompt neutron lifetime caused by variations in the isotope composition of a lead-cooled fast reactor. The generalized small perturbation theory formulas have been developed to calculate derivatives of the prompt neutron lifetime regarded as a bilinear neutron flux and neutron worth ratio. A numerical algorithm has been proposed for the step-by-step application of the small perturbation theory formulas to assess the prompt neutron lifetime variations caused by a major perturbation in the reactor isotope composition, e.g. by the complete change of the material used earlier as the neutron reflector. The advantage of the proposed approach has been shown which consists in that it is basically possible to determine the role of different neutron reactions, isotopes and energy groups in and their contributions to the total prompt neutron lifetime variation caused by major changes in the reactor isotope composition