Aggregate ranking of the world's leading universities

The paper presents a methodology for calculating the aggregate global university ranking (Aggregated Global University Ranking, or AGUR), which consists of an automated presentation of the comparable lists of names for different universities from particular global university rankings and a simple procedure of aggregating particular global university rankingsyesBelgorod State Universit

On the superfluidity of classical liquid in nanotubes

In 2001, the author proposed the ultra second quantization method. The ultra second quantization of the Schr\"odinger equation, as well as its ordinary second quantization, is a representation of the N-particle Schr\"odinger equation, and this means that basically the ultra second quantization of the equation is the same as the original N-particle equation: they coincide in 3N-dimensional space. We consider a short action pairwise potential V(x_i -x_j). This means that as the number of particles tends to infinity, $N\to\infty$, interaction is possible for only a finite number of particles. Therefore, the potential depends on N in the following way: $V_N=V((x_i-x_j)N^{1/3})$. If V(y) is finite with support $\Omega_V$, then as $N\to\infty$ the support engulfs a finite number of particles, and this number does not depend on N. As a result, it turns out that the superfluidity occurs for velocities less than $\min(\lambda_{\text{crit}}, \frac{h}{2mR})$, where $\lambda_{\text{crit}}$ is the critical Landau velocity and R is the radius of the nanotube.Comment: Latex, 20p. The text is presented for the International Workshop "Idempotent and tropical mathematics and problems of mathematical physics", Independent University of Moscow, Moscow, August 25--30, 2007 and to be published in the Russian Journal of Mathematical Physics, 2007, vol. 15, #

Large-scale Samples Irradiation Facility at the IBR-2 Reactor in Dubna

The irradiation facility at the beam line no.3 of the IBR-2 reactor of the Frank Laboratory for Neutron Physics is described. The facility is aimed at irradiation studies of various objects with area up to 800 cm$^2$ both at cryogenic and ambient temperatures. The energy spectra of neutrons are reconstructed by the method of threshold detector activation. The neutron fluence and $\gamma$ dose rates are measured by means of alanine and thermoluminescent dosimeters. The boron carbide and lead filters or $(n/\gamma)$ converter provide beams of different ratio of doses induced by neutrons and photons. For the lead filter, the flux of fast neutrons with energy more than 0.1 MeV is $1.4 \cdot 10^{10}$ \fln and the neutron dose is about 96\% of the total radiation dose. For the $(n/\gamma)$ converter, the $\gamma$ dose rate is $\sim$500 Gy h$^{-1}$ which is about 85\% of the total dose. The radiation hardness tests of GaAs electronics and materials for the ATLAS detector to be put into operation at the Large Hadron Collider (LHC) have been performed successfully at this facility

Сравнение расчетных и измеренных значений мощности кермы в воздухе над почвой, загрязненной 137Cs

In 2010, a study was conducted to determine the air gamma dose rate from 137Cs deposited in soil. The gamma dose rate measurements and soil sampling were performed at 30 reference plots from the south-west districts of the Bryansk region (Russia) that had been heavily contaminated as a result of the Chernobyl accident. The 137Cs inventory in the top 20 cm of soil ranged from 260 kBq m–2 to 2800 kBq m–2. Vertical distributions of 137Cs in soil cores (6 samples per a plot) were determined after their sectioning into ten horizontal layers of 2 cm thickness. The vertical distributions of 137Cs in soil were employed to calculate air kerma rates, K, using two independent methods proposed by Saito and Jacob [Radiat. Prot. Dosimetry, 1995, Vol. 58, P. 29–45] and Golikov et al. [Contaminated Forests– Recent Developments in Risk Identification and Future Perspective. Kluwer Academic Publishers, 1999. – P. 333–341]. A very good coincidence between the methods was observed (Spearman’s rank coefficient of correlation = 0.952; P<0.01); on average, a difference between the kerma rates calculated with two methods did not exceed 3%. The calculated air kerma rates agreed with the measured dose rates in air very well (Spearman’s coefficient of correlation = 0.952; P<0.01). For large grassland plots (n=19), the measured dose rates were on average 6% less than the calculated kerma rates. The tested methods for calculating the air dose rate from 137Cs in soil can be recommended for practical studies in radiology and radioecology. В 2010 г. было проведено исследование, целью которого являлось сравнение расчетных и измеренных значений мощности кермы гамма-излучения в воздухе от радионуклида 137Cs, залегающего в почве. Измерения мощности кермы в воздухе, K , и отбор проб почвы были выполнены на 30 референтных участках, находящихся в юго-западных районах Брянской области России. Эти участки почвы были сильно загрязнены в результате Чернобыльской аварии. Запас 137Cs в верхних 20 см почвы на этих участках колебался от 260 кБк/м2 до 2800 кБк/м2. Исследовано вертикальное распределение активности 137Cs в почве, которое было использовано для расчета мощности кермы в воздухе, K , с применением двух независимых методов, предложенных Saito and Jacob [Radiat. Prot. Dosimetry, 1995, Vol. 58, P. 29–45] и Golikov et al. [Contaminated Forests– Recent Developments in Risk Identification and Future Perspective. Kluwer Academic Publishers, 1999. – P. 333–341]. В среднем расхождение между результатами расчетов двумя методами составило 3% (коэффициент корреляции Спирмена=0,952; P<0,01). Для больших открытых площадок (n=19) обнаружено хорошее согласие между результатами расчетов и результатами измерений мощности кермы в воздухе (коэффициент корреляции Спирмена=0,935; P<0,01). Измеренная мощность кермы в воздухе оказалась в среднем на 6% меньше, чем рассчитанная. Обе расчетные модели могут быть использованы в практических радиоэкологических и радиационно-гигиенических работах для оценки мощности кермы гамма-излучения в воздухе от 137Cs, залегающего в почве

Sn delta-doping in GaAs

We have prepared a number of GaAs structures delta-doped by Sn using the well-known molecular beam epitaxy growth technique. The samples obtained for a wide range of Sn doping densities were characterised by magnetotransport experiments at low temperatures and in high magnetic fields up to 38 T. Hall-effect and Shubnikov-de Haas measurements show that the electron densities reached are higher than for other delta-dopants, like Si and Be. The maximum carrier density determined by the Hall effect equals 8.4x10^13 cm^-2. For all samples several Shubnikov-de Haas frequencies were observed, indicating the population of multiple subbands. The depopulation fields of the subbands were determined by measuring the magnetoresistance with the magnetic field in the plane of the delta-layer. The experimental results are in good agreement with selfconsistent bandstructure calculations. These calculation shows that in the sample with the highest electron density also the conduction band at the L point is populated.Comment: 11 pages text (ps), 9 figures (ps), submitted to Semicon. Science Tech

ПРОБЛЕМЫ РЕВАСКУЛЯРИЗАЦИИ ПРИ ОСТРОМ ИНФАРКТЕ МИОКАРДА С ПОДЪЕМОМ СЕГМЕНТА ST

SUMMARY. Based on the data of 370 patients with acute myocardial infarction with ST segment elevation, problems affecting the efficiency of revascularization treatment by PCI have been analyzed. It has been considered difficult to achieve further reduction in the timing of PCI compared to the available. The acceleration dynamics of ST segment on the electrocardiogram during PCI against thrombolysis and limitations of ECG monitoring during reperfusion in assessing myocardial perfusion have been specified. The necessity and appropriateness of PCI in different periods from the onset of MI have been reasoned. The prospects of using perfusion myocardial SPECT in assessing hypoperfusion and prognosis of restoration of myocardial function have been mentioned. РЕЗЮМЕ. На основании данных о 370 больных острым инфарктом миокарда (ИМ) с подъемом сегмента ST проанализированы проблемы, влияющие на эффективность реваскуляризационного лечения методом чрескожного коронарного вмешательства (ЧКВ). Признано трудно выполнимым дальнейшее сокращение сроков проведения ЧКВ по сравнению с имеющимися. Уточнено ускорение динамики сегмента ST на электрокардиограмме (ЭКГ) при ЧКВ по сравнению с тромболизисом. Уточнены ограничения ЭКГ-контроля при проведении реперфузии в оценке миокардиальной перфузии. Обоснована необходимость и целесообразность выполнения ЧКВ в различные сроки от начала ИМ. Отмечены перспективы использования перфузионной однофотонной эмиссионной компьютерной томографии миокарда в оценке степени гипоперфузии и прогнозе восстановления функции миокарда.

The Effectiveness of Using Rust Converters of Domestic and Foreign Production to Protect Steel Surface from Corrosion

В работе исследованы защитные свойства поверхностных слоев, которые сформированы преобразователями ржавчины различных российских и зарубежных производителей на стальных пластинах, покрытых продуктами коррозии, по отношению к воздействию нейтрального соляно го тумана.The protective properties of the surface layers formed by rust converters of various russian and foreign manufacturers on steel plates coated with corrosion products in relation to the impact of neutral salt spray are investigated in this research.Авторы выражают благодарность научному руководителю — доктору технических наук, профессору Н.Л. Медяник.The authors express their gratitude to the scientific supervisor — doctor of sciences in engineering, professor N.L. Medyanik

ФАРМАКОИНВАЗИВНАЯ ТАКТИКА ЛЕЧЕНИЯ ИНФАРКТА МИОКАРДА

Study objective was to conduct a prospective observational study to assess the effect of pharmacointerventional tactics on the outcome of acute ST-elevation myocardial infarction (STEMI) in terms of mortality.MATERIAL AND METHODS. The study included 405 patients with acute STEMI. The Thrombolysis in Myocardial Infarction (TIMI) Risk Score was used to assess the coronary circulation recovery in a major epicardial coronary artery (CA). Percutaneoous coronary interventions (PCIs) were undertaken either as initial interventions, or in a framework of pharmacointervantional treatment tactics.RESULTS. Among 405 patients with STEMI, 154 (38%) underwent a thrombolytic therapy (TLT). Coronarography performed within 24 h from the onset of disease clinical symptoms demonstrated a completely occluded CA that had supplied blood to the area of present infarction in 73% of patients without previous TLT and in 74% of patients after TLT. TLT proved to be effective only in 36 % of patients. A successful revascularization, compared to that of inefficient, reduced the relative all-cause mortality risk and MI-caused mortality risk in the initially high-risk patients by 74% and 78 %, respectively.concLusIons A timely myocardium revascularization using PCI is effective after successfully performed TLT. This proves the benefit of pharmacointerventional treatment tactics for the patients with STEMI in the cases when initial PCI appeared impossible for some reasons. ЦЕЛЬ ИССЛЕДОВАНИЯ. В ходе выполнения проспективного обсервационного исследования оценить влияние фармакоинвазивной тактики лечения больных острым инфарктом миокарда (ИМ) с подъемом сегмента ST на летальность.МАТЕРИАЛ И МЕТОДЫ. В исследование были включены данные о 405 больных с острым ИМ с подъемом сегмента ST. Для оценки степени восстановления коронарного кровотока в крупной эпикардиальной коронарной артерии использовали классификацию TIMI (Thrombolysis In Myocardial Infarction) [7]. Чрескожное вмешательство на коронарной артерии выполняли в виде первичных вмешательств либо в рамках фармакоинвазивной тактики.РЕЗУЛЬТАТЫ. Из 405 больных с ИМ с подъемом сегмента ST тромболитическая терапия (ТЛТ) была выполнена у 154 больных (38%). По данным коронарографии, выполненной в течение 24 ч после развития клинических проявлений заболевания, полная окклюзия коронарной артерии, кровоснабжавшей зону инфаркта, в отсутствие предшествующей тромболитической терапии (ТЛТ) и после выполнения ТЛТ была выявлена у 73% и 47% больных соответственно. ТЛТ оказалась эффективной лишь у 36% больных. При успешной реваскуляризации по сравнению с неэффективной относительный риск смерти от любой причины и смерти от ИМ у больных с исходно более высоким риском снижался на 74% и 78% соответственно.ВЫВОДЫ. Своевременная реваскуляризация миокарда с помощью ЧВКА эффективна после выполнения успешной ТЛТ, что свидетельствует об обоснованности фармакоинвазивной тактики лечения больных острым ИМ с подъемом сегмента ST в случаях, когда выполнение первичного ЧВКА по каким-либо причинам оказалось невозможным.

К МЕТОДИКЕ ОЦЕНКИ ПЕРФУЗИИ МИОКАРДА ЛЕВОГО ЖЕЛУДОЧКА ПРИ ИНФАРКТЕ МИОКАРДА С ПОМОЩЬЮ ОДНОФОТОННОЙ ЭМИССИОННОЙ КОМПЬЮТЕРНОЙ ТОМОГРАФИИ

SUMMARY. On the basis of single photon emission computed tomography of the myocardium (SPECT) with Technetril 99mTc performed in 81 patients with myocardial infarction (MI), we confirmed the proportion of myocardial segments of the left ventricle (LV) with varying degrees of RP inclusion and, therefore, with varying degrees of perfusion impairment. In 75% of patients, reduction of hypoperfusion area in the remote period after myocardial infarction has been revealed compared to the acute period. The relation between slow ECG evolution with the severe impairment of left ventricular myocardial perfusion has been showed. The relation between the degree of impairment of LV myocardial perfusion (by SPECT) and its contraction (according to the two-dimensional echocardiogram) has been revealed. It is shown that one of the leading factors in the restoration of myocardial perfusion is the time of intracoronary intervention. РЕЗЮМЕ. На основании проведения у 81 больного инфарктом миокарда (ИМ) перфузионной однофотонной эмиссионной компьютерной томографии (ОФЭКТ) миокарда с 99mTc-технетрилом уточнено соотношение сегментов миокарда левого желудочка (ЛЖ) с разной степенью включения радиофармпрепарата и, следовательно, с разной степенью нарушения перфузии. У 75% пациентов установлено сокращение площади гипоперфузии в отдаленный период инфаркта по сравнению с острым. Продемонстрирована связь замедленной ЭКГ-эволюции ИМ с глубокими расстройствами перфузии миокарда ЛЖ. Выявлена взаимосвязь степени нарушения перфузии миокарда ЛЖ (по данным ОФЭКТ) и его сократимости (по данным двухмерной Эхо-КГ). Показано, что одним из ведущих факторов восстановления перфузии миокарда является время выполнения внутрико- ронарного вмешательства.

The significance of cephalopod beaks as a research tool: An update

The use of cephalopod beaks in ecological and population dynamics studies has allowed major advances of our knowledge on the role of cephalopods in marine ecosystems in the last 60 years. Since the 1960's, with the pioneering research by Malcolm Clarke and colleagues, cephalopod beaks (also named jaws or mandibles) have been described to species level and their measurements have been shown to be related to cephalopod body size and mass, which permitted important information to be obtained on numerous biological and ecological aspects of cephalopods in marine ecosystems. In the last decade, a range of new techniques has been applied to cephalopod beaks, permitting new kinds of insight into cephalopod biology and ecology. The workshop on cephalopod beaks of the Cephalopod International Advisory Council Conference (Sesimbra, Portugal) in 2022 aimed to review the most recent scientific developments in this field and to identify future challenges, particularly in relation to taxonomy, age, growth, chemical composition (i.e., DNA, proteomics, stable isotopes, trace elements) and physical (i.e., structural) analyses. In terms of taxonomy, new techniques (e.g., 3D geometric morphometrics) for identifying cephalopods from their beaks are being developed with promising results, although the need for experts and reference collections of cephalopod beaks will continue. The use of beak microstructure for age and growth studies has been validated. Stable isotope analyses on beaks have proven to be an excellent technique to get valuable information on the ecology of cephalopods (namely habitat and trophic position). Trace element analyses is also possible using beaks, where concentrations are significantly lower than in other tissues (e.g., muscle, digestive gland, gills). Extracting DNA from beaks was only possible in one study so far. Protein analyses can also be made using cephalopod beaks. Future challenges in research using cephalopod beaks are also discussed.info:eu-repo/semantics/publishedVersio