THERMAL STABILITY AND EXTRA-STRENGTH OF AN ULTRAFINE GRAINED STAINLESS STEEL PRODUCED BY HIGH PRESSURE TORSION

International audienceInvestigations of an ultrafine-grained (UFG) Cr-Ni austenitic stainless steel produced by high pressure torsion (HPT) at room and elevated (400 C) temperatures followed by series of annealing up to 700 C are reported. The grain size of the alloy processed at room temperature (55 nm) was found to be about twice lower than the grain size of the alloy (90 nm) processed at elevated temperature. Besides, both as-processed states demonstrated a very high value of microhardness (~590 Hv) , while the steel in initial quenched state had the microhardness about 155 Hv. It is shown that the hardness of the steel in both UFG states does not decrease with annealing up to 650 C, and even a certain increase in hardness was observed for the steel produced at room temperature. At higher temperature (700 C), the recrystallization starts, and precipitation was observed

Muon-Induced Background Study for Underground Laboratories

We provide a comprehensive study of the cosmic-ray muon flux and induced activity as a function of overburden along with a convenient parameterization of the salient fluxes and differential distributions for a suite of underground laboratories ranging in depth from $\sim$1 to 8 km.w.e.. Particular attention is given to the muon-induced fast neutron activity for the underground sites and we develop a Depth-Sensitivity-Relation to characterize the effect of such background in experiments searching for WIMP dark matter and neutrinoless double beta decay.Comment: 18 pages, 28 figure

Transvaginal mesh-reconstruction of anterior apical prolapse: a selective implant choosing approach

Introduction. Transvaginal mesh-reconstruction of urogenital prolapse remains a controversial trend in modern urogynecology. We have seen growth in transvaginal mesh surgery since 2004, followed by a sharp decline after 2011 due to FDA restrictions related to imperfections in previously available prostheses and implantation techniques. Improving the efficacy and minimizing complications of transvaginal mesh-surgery is at the forefront of research in the field of modern urogynecology.Purpose of the study. To optimize the indications for transvaginal mesh-reconstruction of anterior apical prolapse.Materials and methods. The study enrolled 375 patients with anterior apical prolapse. The grade of prolapse was assessed using POP-Q. In patients with endopelvic pelvic fascia insufficiency, severe cystocele (Aa ≥ +1) and hysteroptosis grade II – IV, the correction was carried out using the six-arm OPUR® («ABISS», Saint-Étienne, France). lightweight polypropylene monofilament implant (n = 290). When the cystocele was not prominent (Aa ≤ -1) and grade III – IV hysteroptosis, posterior sacrospinal hysteropexy was preferred with the CYRENE® («ABISS», Saint-Étienne, France) tape (n = 85). In 35 patients, the operation was combined with anterior colporrhaphy. In 5 patients, a simultaneous conization/amputation of the cervix was performed. The examination was performed 1 month after surgery and then annually. Prolapse ≥ grade II was as recurrent. The follow-up period of 67 patients was more than 4 years.Results. After OPUR® prosthesis implantation, recurrent hysteroptosis was detected in 6 women with cervical hypertrophy / elongation within a period of 1 mo to 3.5 yr and cystocele in 4 patients. The efficacy was 96%. In 9 patients, an postoperative ischuria was found associated with extensive dissection and hypotension of the bladder wall due to chronic urinary retention in severe cystocele. Urination improved in 88% of cases. In the remaining cases, long-term mediator and hormone replacement therapy were continued., One recurrent hysteroptosis was observed during the implantation of the CYRENE® prosthesis. No damage to the bladder was observed. Acute urinary retention was detected in 1 case, which resolved after intermittent catheterization. Conclusion. The availability of 2 types of transvaginal prostheses for various degrees and configurations of urogenital prolapses allows a differentiated approach to their choice. Both prostheses suggest reliable «reconstruction-imitation» of the sacroiliac ligament by sacrospinal hysteropexy. If necessary, the operation can be supplemented with anterior colporrhaphy. The prevalence of anterior prolapse with endopelvic fascia insufficiency requires more extensive reconstruction, which can be performed relatively safely and effectively by implantation of a 6-arm OPUR® prosthesis

The Microstructure and Strength of UFG 6060 alloy after superplastic deformation at a lower homologous temperature

The paper reports on the features of low-temperature superplasticity of the heat-treatable aluminum Al-Mg-Si alloy in the ultrafine-grained state at temperatures below 0.5 times the melting point as well as on its post-deformation microstructure and tensile strengt

Production of Radioactive Isotopes through Cosmic Muon Spallation in KamLAND

Radioactive isotopes produced through cosmic muon spallation are a background for rare-event detection in $\nu$ detectors, double-$\beta$-decay experiments, and dark-matter searches. Understanding the nature of cosmogenic backgrounds is particularly important for future experiments aiming to determine the pep and CNO solar neutrino fluxes, for which the background is dominated by the spallation production of $^{11}$C. Data from the Kamioka liquid-scintillator antineutrino detector (KamLAND) provides valuable information for better understanding these backgrounds, especially in liquid scintillators, and for checking estimates from current simulations based upon MUSIC, FLUKA, and GEANT4. Using the time correlation between detected muons and neutron captures, the neutron production yield in the KamLAND liquid scintillator is measured to be $(2.8 \pm 0.3) \times 10^{-4} \mu^{-1} g^{-1} cm^{2}$. For other isotopes, the production yield is determined from the observed time correlation related to known isotope lifetimes. We find some yields are inconsistent with extrapolations based on an accelerator muon beam experiment.Comment: 16 pages, 20 figure

The ethnic-specific spectrum of germline nucleotide variants in DNA damage response and repair genes in hereditary breast and ovarian cancer patients of Tatar descent

© 2018 Frontiers Media S.A. All Rights Reserved. The Russian population consists of more than 100 ethnic groups, presenting a unique opportunity for the identification of hereditary pathogenic mutations. To gain insight into the landscape of heredity pathogenic variants, we employed targeted next-generation sequencing to analyze the germline mutation load in the DNA damage response and repair genes of hereditary breast and ovary cancer syndrome (HBOCS) patients of Tatar ethnicity, which represents ∼4% of the total Russian population. Several pathogenic mutations were identified in DNA double-strand break repair genes, and the spectrum of these markers in Tatar patients varied from that previously reported for patients of Slavic ancestry. The CDK12 gene encodes cyclin-dependent kinase 12, the key transcriptional regulator of the genes involved in DNA damage response and repair. CDK12 analysis in a cohort of HBOCS patients of Tatar decent identified a c.1047-2A>G nucleotide variant in the CDK12 gene in 8 of the 106 cases (7.6%). The c.1047-2A>G nucleotide variant was identified in 1 of the 93 (1.1%) HBOCS patients with mixed or unknown ethnicity and in 1 of the 238 (0.42%) healthy control patients of mixed ethnicity (Tatars and non-Tatars) (p = 0.0066, OR = 11.18, CI 95% = 1.53-492.95, Tatar and non-Tatar patients vs. healthy controls). In a group of mixed ethnicity patients from Tatarstan, with sporadic breast and/or ovarian cancer, this nucleotide variant was detected in 2 out of 93 (2.2%) cases. In a cohort of participants of Slavic descent from Moscow, comprising of 95 HBOCS patients, 80 patients with sporadic breast and/or ovarian cancer, and 372 healthy controls, this nucleotide variant was absent. Our study demonstrates a strong predisposition for the CDK12 c.1047-2A>G nucleotide variant in HBOCS in patients of Tatar ethnicity and identifies CDK12 as a novel gene involved in HBOCS susceptibility

Активация аутофагии в клетках рака молочной железы in vitro после воздействия ингибиторами PI3K/AKT/mTOR

Introduction. Current chemotherapy of breast cancer has a wide range of disadvantages, in particular, the development of therapy-related infections and hormonal imbalance. Combination of main cytostatic with glucocorticoids allows to broaden its therapeutic interval and to decrease the total toxicity of the treatment. However, long-term treatment with glucocorticoids leads to the development of severe side effects via activation of multiple molecular mechanisms. Thus, glucocorticoids activate prosurvival mTOR-dependent autophagy. Therefore, the evaluation of PI3K (phosphoinositide 3-kinases) / Akt (protein kinase B) / mTOR (mammalian target of rapamycin) inhibitors as adjuvants for breast cancer therapy is important for optimization of treatment protocol.Aim. Analysis of the effects of PI3K/Akt/mTOR inhibitors, rapamycin, wortmannin and LY-294002 in combination with glucocorticoids in breast cancer cell lines of different subtypes.Materials and methods. We demonstrated the inhibition of PI3K/Akt/mTOR signaling and the autophagy induction after the treatment of breast cancer cells with rapamycin, wortmannin and LY-294002 by Western blotting analysis of Beclin-1, phospho-Beclin-1 (Ser93 and Ser30).Conclusion. PI3K/Akt/mTOR inhibitors in combination with Dexamethasone cooperatively inhibited mTOR signaling and activated autophagy in breast cancer cells in vitro.Введение. Химиотерапия рака молочной железы имеет широкий спектр недостатков, в частности развитие сопутствующих инфекций и гормональных нарушений. Комбинация с синтетическими глюкокортикоидами позволяет расширить терапевтический интервал и снизить общую токсичность препаратов основной линии терапии. Однако длительное применение глюкокортикоидов способствует развитию ряда побочных эффектов, которые могут реализовываться за счет различных молекулярных механизмов. Так, глюкокортикоиды могут инициировать индукцию аутофагии, ведущую к выживанию опухолевых клеток. Запуск механизма аутофагии является mTOR-зависимым, в связи с чем актуальной является оценка возможности введения в качестве адъювантов в терапию рака молочной железы ингибиторов сигнального пути PI3K (фосфоинозитид-3‑киназа) / Akt (протеинкиназа B) / mTOR (мишень рапамицина млекопитающих).Цель работы – анализ действия ингибиторов PI3K / Akt / mTOR рапамицина, вортманнина и LY-294002 в комбинации с глюкокортикоидами на запуск аутофагии в клеточных линиях рака молочной железы различного гистогенеза.Материалы и методы. Методом Вестерн-блоттинга было показано, что рапамицин, вортманнин и LY-294002 ингибируют активность сигнального пути PI3K / Akt / mTOR и индуцируют аутофагию в клетках рака молочной железы, о чем судили по повышению уровня ключевого белка макроаутофагии, Beclin-1, и его фосфорилированных форм phospho-Beclin-1 по остаткам серина Ser93 и Ser30.Заключение. В ходе работы было показано, что ингибиторы сигнального пути PI3K / Akt / mTOR в комбинации с дексаметазоном кооперативно подавляют сигнальный путь mTOR и активируют аутофагию в клетках РМЖ in vitro

Neutron production by cosmic-ray muons at shallow depth

The yield of neutrons produced by cosmic ray muons at a shallow depth of 32 meters of water equivalent has been measured. The Palo Verde neutrino detector, containing 11.3 tons of Gd loaded liquid scintillator and 3.5 tons of acrylic served as a target. The rate of one and two neutron captures was determined. Modeling the neutron capture efficiency allowed us to deduce the total yield of neutrons $Y_{tot} = (3.60 \pm 0.09 \pm 0.31) \times 10^{-5}$ neutrons per muon and g/cm$^2$. This yield is consistent with previous measurements at similar depths.Comment: 12 pages, 3 figure

Upper Limit on the Prompt Muon Flux Derived from the LVD Underground Experiment

We present the analysis of the muon events with all muon multiplicities collected during 21804 hours of operation of the first LVD tower. The measured depth-angular distribution of muon intensities has been used to obtain the normalization factor, A, the power index, gamma, of the primary all-nucleon spectrum and the ratio, R_c, of prompt muon flux to that of pi-mesons - the main parameters which determine the spectrum of cosmic ray muons at the sea level. The value of gamma = 2.77 +/- 0.05 (68% C.L.) and R_c < 2.0 x 10^-3 (95% C.L.) have been obtained. The upper limit to the prompt muon flux favours the models of charm production based on QGSM and the dual parton model.Comment: 10 pages, 4 figures, RevTex. To appear in Phys. Rev.

On inconsistency of experimental data on primary nuclei spectra with sea level muon intensity measurements

For the first time a complete set of the most recent direct data on primary cosmic ray spectra is used as input into calculations of muon flux at sea level in wide energy range $E_\mu=1-3\cdot10^5$ GeV. Computations have been performed with the CORSIKA/QGSJET and CORSIKA/VENUS codes. The comparison of the obtained muon intensity with the data of muon experiments shows, that measurements of primary nuclei spectra conform to sea level muon data only up to several tens of GeV and result in essential deficit of muons at higher energies. As it follows from our examination, uncertainties in muon flux measurements and in the description of nuclear cascades development are not suitable to explain this contradiction, and the only remaining factor, leading to this situation, is underestimation of primary light nuclei fluxes. We have considered systematic effects, that may distort the results of the primary cosmic ray measurements with the application of the emulsion chambers. We suggest, that re-examination of these measurements is required with the employment of different hadronic interaction models. Also, in our point of view, it is necessary to perform estimates of possible influence of the fact, that sizable fraction of events, identified as protons, actually are antiprotons. Study of these cosmic ray component begins to attract much attention, but today nothing definite is known for the energies $>40$ GeV. In any case, to realize whether the mentioned, or some other reasons are the sources of disagreement of the data on primaries with the data on muons, the indicated effects should be thoroughly analyzed