The blue vibronically resolved electroluminescence of azatrioxa[8]circulene

Organic Light Emitting Dioides (OLED)devices were fabricated with blue emission based on azatrioxa[8]circulene and 4,4-N,N'-Dicarbazolyl-1,1'-biphenyl (CBP) with maximum brightness of 840 kd/m(2) at 12 V and the starting voltage of 3.5 V. The vibronic emission spectrum was analyzed by the promotive modes calculation method. The electroluminescence of fabricated OLED device is caused by the 0-0 electronic transition and single excitations of 1473 cm(-1) and 1673 cm(-1) modes and combinations thereof.Peer reviewe

High-Pressure torsion-Induced Grain Growth in Electrodeposited Nanocrystalline Ni

Deformation-induced grain growth has been reported in nanocrystalline (nc) materials under indentation and severe cyclic loading, but not under any other deformation mode. This raises an issue on critical conditions for grain growth in nc materials. This study investigates deformation-induced grain growth in electrodeposited nc Ni during high-pressure torsion (HPT). Our results indicate that high stress and severe plastic deformation are required for inducing grain growth, and the upper limit of grain size is determined by the deformation mode and parameters. Also, texture evolution suggests that grain-boundary-mediated mechanisms played a significant role in accommodating HPT strain

Influence of severe plastic deformation on the precipitation hardening of a FeSiTi steel

The combined strengthening effects of grain refinement and high precipitated volume fraction (~6at.%) on the mechanical properties of FeSiTi alloy subjected to SPD processing prior to aging treatment were investigated by atom probe tomography and scanning transmission electron microscopy. It was shown that the refinement of the microstructure affects the precipitation kinetics and the spatial distribution of the secondary hardening intermetallic phase, which was observed to nucleate heterogeneously on dislocations and sub-grain boundaries. It was revealed that alloys successively subjected to these two strengthening mechanisms exhibit a lower increase in mechanical strength than a simple estimation based on the summation of the two individual strengthening mechanisms

Outcomes in poor responders treated with in vitro fertilization/intracytoplasmic sperm injection according to bologna criteria

Purpose of the study was to evaluate the effectiveness of various approaches of artificial reproductive technologies (ART) in advanced maternal age patients with poor ovarian response (POR). Materials and methods. This is retrospective cohort study of 455 patients with POR who have undergone an IVF and embryo transfer program at from June 2016 to June 2018. Researchers evaluated pregnancy rate (PR) per embryo transferand live birth rate (LBR) per embryo transferas in vitro fertilization (IVF) outcomes. The patients fulfilled Bologna criteria were divided into 5 groups: long protocol, ant-gonadotropin-releasing hormone protocol, freeze embryos transfer without preimplantation genetic diagnostic (PGS), freeze embryos transfer with PGS, natural cycle. Results. There was no statistically significant difference in the age, Anti-Müllerian hormone level and duration of infertility between the groups. Despite different protocols of ovarian stimulation, there was no statistically significant difference in pregnancy rate in fresh cycles. At the same time, cancellation of transfer was significantly higher observed in natural cycles (p <0.001). PR and LBR were statistically significant higher in freeze embryo transfer group 29% and 12.1% vs 13.3% and 5,5% respectively (p<0.001 and p = 0.040). During the transfer of the embryo unexamined by PGS and after PGS the pregnancy rate did not differ (29.4% vs 28.2%, p <0.05), but LBR was statistically significant higher after euploid embryo transfer (8.2% without PGS vs 20.5% after PGS, p = 0.028). Conclusion. The most effective approach in patients with a poor ovarian response was cycle segmentation, cryopreservation of embryos, PGS and transfer of an euploid embryo. This category of patients requires a personalized approach to the treatment of infertility. The choice of protocol in ART program must be carried out with the full voluntary and informed consent of the patient, depending on their desires and capabilities, including financial

A new look at acid catalyzed deacetylation of carbohydrates : A regioselective synthesis and reactivity of 2-O-acetyl aryl glycopyranosides

Abstract In the present work we report that acetyl groups of per – acetylated aryl glycosides have different reactivity during the acidic deacetylation using HCl/EtOH in CHCl3, which leads to preferential deacetylation at O-3, O-4 and O-6. Thereby, the one-step preparation of 2-O-acetyl aryl glycosides with simple aglycon was accomplished for the first time. It was proved that the found reagent is to be general and unique for the preparation of series of 2-О-acetyl aryl glycosides. We have determined the influence of both carbohydrate moiety and the aglycon on the selectivity of deacetylation reaction by kinetic experiments. Using DFT/B3LYP/6-31G(d,p) and semi-empirical АМ1 methods we have found that the highest activation barrier is for 2-О-acetyl group. This completely explains the least reactivity of 2-О-acetyl group.Peer reviewe

Experience Of The International Cooperation of the Archaeological Institute named after A.Kh. Khalikov TAS with Scientific Organizations of Uzbekistan in 2022-2023

The Institute of Archaeology named after A.Kh. Khalikov of the Tatarstan Academy of Sciences has been actively cooperating with scientific centres and universities of the Republic of Uzbekistan since 2022. One of the fields of cooperation is the implementation of the scientific and educational project "Bolgar International Archaeological School". The support of the International Institute for Central Asian Studies (Samarkand, Uzbekistan) and the successful implementation of the scientific and educational project served as the beginning of closer and fruitful cooperation. In March 2023, jointly with Termez State University, an interdisciplinary study of the archaeological heritage site "Palace of Termezshahs", dating from the XI–XII centuries, was carried out. In May-June 2023, archaeological studies were conducted together with the Nukus State Pedagogical Institute named after Ajiniyaz on the Khaivan-Kala fortified settlement of the VII–X centuries. Within the scientific and educational cooperation at Termez State University, specialists of the Institute of Archaeology named after A.Kh. Khalikov RT implemented an additional professional training programme "Geoinformation technologies and non-destructive methods"

Electron transport and optical properties of shallow GaAs/InGaAs/GaAs quantum wells with a thin central AlAs barrier

Shallow GaAs/InGaAs/GaAs quantum well structures with and without a three monolayer thick AlAs central barrier have been investigated for different well widths and Si doping levels. The transport parameters are determined by resistivity measurements in the temperature range 4-300 K and magnetotransport in magnetic fields up to 12 T. The (subband) carrier concentrations and mobilities are extracted from the Hall data and Shubnikov-de Haas oscillations. We find that the transport parameters are strongly affected by the insertion of the AlAs central barrier. Photoluminescence spectra, measured at 77 K, show an increase of the transition energies upon insertion of the barrier. The transport and optical data are analyzed with help of self-consistent calculations of the subband structure and envelope wave functions. Insertion of the AlAs central barrier changes the spatial distribution of the electron wave functions and leads to the formation of hybrid states, i.e. states which extend over the InGaAs and the delta-doped layer quantum wells.Comment: 14 pages, pdf fil

Renalase – a new instrument in multicomponent heart failure assessment

Heart failure (HF) remains a serious problem in Russian and world health care due to the growing morbidity and mortality from complications of heart failure, despite the development and implementation of programs for the early detection and treatment of heart failure in asymptomatic patients. Currently, a large number of new biological markers have been studied that could serve as a laboratory tool for diagnosing and predicting the course of heart failure, but only brain natriuretic peptides have found application in real clinical practice. Renalase is a recently discovered cytokine that is synthesized by the kidneys and released into the blood. To date, seven subtypes of renalase have been found, each of which plays a different physiological role in the human body. Renalase is usually positioned as a signaling molecule that activates cytoprotective intracellular signals, leading to a decrease in blood pressure and protection of the heart muscle. The concentration of renalase freely circulating in the bloodstream of an adult is approximately 3–5 ng / ml. Currently, the level of renalase is determined by the enzyme immunoassay with a detection range of 3.12 to 200 ng / ml, while the minimum detectable concentration of the marker is less than 1.38 ng / ml. The presence of missense polymorphism of renalase is associated with myocardial dysfunction. Data from animal and human studies have shown that renalase plays a key role in the metabolism of catecholamines and in cardioprotective processes. Studies have shown the contribution of renalase to the occurrence of cardiovascular diseases: ischemic heart disease, arterial hypertension, diabetes mellitus, and aortic stenosis. Moreover, detailed protocols of multicenter prospective studies have demonstrated that functional polymorphism of the renalase gene was associated with myocardial hypertrophy in patients with aortic stenosis, hypertension, metabolic syndrome, unstable angina pectoris and stable forms of coronary artery disease, as well as in patients receiving renal replacement therapy. Based on these data and further studies, renalase has been proposed as a predictive biomarker of ischemia in patients with coronary microvascular dysfunction, as well as a predictor of clinically significant progression of chronic kidney disease in patients with cardiovascular diseases.Our review presents data on the role of renalase in heart failure. Further study of the structure and function of renalase, as well as future clinical studies, will allow determining the diagnostic, prognostic and, possibly, therapeutic significance of this biological marker in HF and other cardiovascular diseases

Anatomical and physiological characteristics of a pregnant woman as a predictor of the symphusiopathy development

The article deals main factors contributing to the development of symphysiopathy during pregnancy. A model of an average woman with a high probability of developing symphysiopathy also created.В статье рассмотрены основные факторы, способствующие развитию симфизиопатии во время беременности. Разработана модель среднестатистической женщины с высокой вероятностью развития симфизиопатии