Investigation of the temporal fluctuations of the 1960–2010 seismicity of Caucasus

The time-clustering behaviour of the seismicity of the Caucasus spanning from 1960 to 2010 was investigated. The analysis was performed on the whole and aftershock-depleted catalogues by means of the method of Allan Factor, which permits the identification and quantification of time-clustering in point processes. The whole sequence is featured by two scaling regimes with the scaling exponent at intermediate timescales lower than that at high timescales, and a crossover that could be probably linked with aftershock time activiation. The aftershock-depleted sequence is characterized by higher time-clustering degree and the presence of a periodicity probably correlated with the cyclic earth surface load variations on regional and local scales, e.g. with snow melting in Caucasian mountains and large Enguri dam operations. The obtained results were corroborated by the application of two surrogate methods: the random shuffling and the generation of Poissonian sequences

A novel method for bone fatigue monitoring and prediction

Bone fatigue, often manifest as stress fractures, is a common injury that plagues many individuals, adversely affect quality of life, and is an obstacle to extended human spaceflight. This manuscript details a pilot study that was conducted to determine if the Phase Space Warping (PSW) methodology could be used to monitor/predict fatigue failure in bone tissue. A Moon\u27s beam experimental apparatus was used to perform variable amplitude fatigue tests on bovine bone specimens. Scanning electron microscopy was used to evaluate the fracture surface and identify the fracture type. The PSW method allowed for successful identification of the various damage modes and may lead to the development of a viable tool for predicting the health and fatigue life of bone

Скрининг сердечно-сосудистой системы футбольных арбитров перед игрой: клинические результаты и опыт

Arbitrii de fotbal sunt supuși unui efort fizic analogic sportivilor profesioniști în timpul meciului, totodată aceştia sunt implicați intens în cantonamentul săptămânal înainte de meci. Prin urmare, arbitrii de fotbal, asemeni sportivilor, riscă să facă moarte subită cardiacă (MSC), cauzată de insuficiența cardiacă de bază.Футбольные арбитры испытывают аналогичные физические нагрузки как и профессиональные игроки во время матча, а также они часто подвергаются долгосрочной интенсивной недельной подготовке перед матчем. Следовательно, судьи одинаково подвержены риску внезапной сердечной смерти (ВСС) из-за основных сердечных расстройств

Compression-induced electrical percolation and enhanced mechanical properties of polydimethylsiloxane-based nanocomposites

YesIn this work, a compression-induced percolation threshold was found when the thickness of polydimethylsiloxane (PDMS) nanocomposite samples was reduced via a spatial confining forced network assembly (SCFNA) process from 1.0 mm to 0.1 mm. Such as for PDMS/2 wt% short carbon fiber/4 wt% carbon nanotube (CNT) composite, its conductivity was more than 8 times enhanced to 487 S/m from 59.5 S/m, and the mechanical properties of composites have been improved by more than 15% accordingly. Comparatively, when increased the concentration of CNT or Gr from 1 to 4 wt%, the electrical conductivity of PDMS nanocomposites at 1 mm thickness was barely changed as it generally reached saturation and became independent of filler loading. Compared with the traditional blending method, it indicates that the SCFNA process can further promote the maximum electrical conductivity of polymer nanocomposites when the filler concentration has little effect on the conductivity. Especially under the condition of relatively high filler concentration, the electrical conductivity enhancement effect becomes more significant that is contrary to the classical percolation theory. Moreover, the mechanical properties of the nanocomposites can be slightly improved by the mechanical compression, which makes it more suitable for flexible electronic devices' applications

New Ways of Radiation Migration into Natural Environment by Means of Cesium-Rich Condensed Micro-Particles (CsMPs)

Cesium-rich micro-particles - CsMPs - generated at the Fukushima nuclear power plant were first detected in atmospheric particles 170 km southwest of the plant. Particle formation took place during melting inside the reactor. These particles provide important information about the physical and chemical properties of radioactive materials inside the reactor. A high-resolution transmission electron microscope as well as conventional radio-analytical techniques were used for their study

On Indoor Environment Contamination by Cesium-Rich Radioactive Microparticles Released from the Fukushima Daiichi Nuclear Power Plant: A Review

Advanced nuclear technologies in conditions of geological disaster can lead to unpredictable ecological hazards. Through unknown processes Cesium-rich micro-particles CsMPs formation took place during melting inside the reactor. Not much has been documented on the occurrence of CsMPs inside buildings. After Fukushima disaster new ways of radiation contamination of the natural environment by CsMPs were identified

ОКСИДАТИВНИЙ СТРЕС – ЯК СУРОГАТ НЕСТАБІЛЬНОСТІ КОРОНАРНОЇ АТЕРОСКЛЕРОТИЧНОЇ БЛЯШКИ ТА ПРЕДИКТОР ЇЇ РОЗРИВУ

Background. Oxidative stress is crucial in developing broad spectrum of diseases, including atherosclerosis and related life-threatening conditions, such as acute coronary syndrome (ACS) mainly caused by atherosclerotic plaque vulnerability. Objective. To clarify the relation between oxidative stress and plaque instability we decided to compare oxidative profiles of patients with acute coronary syndrome (ACS) and with chronic coronary syndrome (CCS), evaluated at admission to the coronary care unit (CCU) of LTD Clinic-LJ (Kutaisi, Georgia) in April 2018 - June 2019, who underwent successful primary percutaneous coronary intervention (PCI). Methods. 191 patients were enrolled (100 patients with ACS in Group 1 and 91 patients with CCS in Group 2) into the study. Using the CR3000 FORM PLUS (Callegari Srl, Catellani Group, Italy) – Callegari Point of Care instrument we evaluated free oxygen radical test (FORT), free oxygen radicals defense (FORD), calculated REDOX Index and the overall Profile of oxidative stress. Results. The mean/median concentration of Free Oxygen Radicals was significantly higher in the patients with ACS (404.37±9.83 Fort units/2.36 mmol/l H2O2 eq. vs 282.34±9.83 Fort units/2.36 mmol/l H2O2 eq., p<0.0001). Significant correlation was found between advanced oxidative stress and acute coronary syndrome (OR 14.42 95% CI (7.08-29.4), RR 3.26 95% CI (2.31-4.60) with high diagnostic characteristics (sensitivity of 82% and specificity of 92.3%; positive predictive value of 92% and positive likelihood ratio of 11). Conclusion. Oxidative stress is crucial in life-threatening acute coronary events. Measurement of overall oxidative stress profile, as a surrogate of plaque instability and rupture predictor, could help the clinicians in risk stratification and prevention of acute coronary syndrome (ACS).Вступ. Оксидативний стрес відіграє важливу роль у патогенезі багатьох захворювань, в тому числі атеросклерозу та його ускладнень, як гострий коронарний синдром (ГКС), що переважно зумовлений нестабільністю атеросклеротичної бляшки. Мета – з’ясувати  взаємозв’язок ступенем оксидативного стресу та нестабільністю бляшки шляхом порівняння оксидативного профілю пацієнтів з ГКС та хронічним коронарним синдромом (ХКС). Дослідження проводили у кардіологічному відділені LTD Клініки-LJ (Кутаїсі, Грузія) в період з квітня 2018 року до червня 2019 року серед пацієнтів, котрим успішно було проведено первинні перкутанні коронарні втручання (ПКВ). Методи. До дослідження було залучено 191 пацієнта (100 пацієнтів з ГКС (Група 1) та 91 пацієнт з ХКС (Група 2). Досліджували такі показники: тест для визначення інтенсивності вільнорадикальних реакцій (Free Oxygen Radical Test, FORT); тест для визначення антиоксидантної здатності (Free Oxygen Radicals Defense Test, FORD); визначали REDOX індекс та Профіль оксидативного стресу за допомогою CR3000 FORM PLUS (Callegari Srl, Catellani Group, Italy).   Результати. Концентрація вільних радикалів кисню була достовірно вищою у пацієнтів з ГКС (404,37±9,83 vs 282,34±9,83 Fort од/2.36 ммоль/л H2O2 екв., p<0,0001). Між інтенсивністю оксидативного стресу та розвитком гострого коронарного синдрому встановлено вірогідні кореляційні зв’язки (OR 14,42 95% CI (7.08-29.4), RR 3,26 95% CI (2,31-4,60) з високими діагностичними характеристиками (чутливість 82,0% та специфічність 92,3%; позитивна прогностична роль 92,0% та позитивний коефіцієнт вірогідності 11). Висновки. Оксидативний стрес відіграє вирішальну роль при гострих коронарних подіях, що загрожують життю. Вимірювання оксидативного профілю, як сурогату нестабільності атеросклеротичної бляшки та предиктора її розриву, може допомогти лікарю у стратифікації ризику коронарних подій для попередження гострого коронарного синдрому (ГКС). &nbsp

Relationship between seismicity and water level in the Enguri high dam area (Georgia) using the singular spectrum analysis

The declustered seismic catalog from 1965 to 2010 around the Enguri high dam reservoir in western Georgia was analyzed using the singular spectrum analysis (SSA) technique in order to investigate the relationship of local seismicity with the reservoir water variations. In particular, the seismic activity was analyzed in two periods: a "reference" period, from 1965 to 1970, before the start of dam building in 1971; and an "active" period, from 1978 to 2010, in which the influence of the reservoir was significantly effective on the seismic activity (since the first flooding of the dam occurred in 1978). The SSA was applied to both the monthly number of earthquakes and the time series of the monthly mean of the water level. The first four reconstructed components explained most of the total variance in both seismicity and water level. Clear signatures of the annual oscillation linked with the loading/unloading operations of the dam are present in the periodogram of the second and the third reconstructed components of the seismic activity during the "active" period. Such annual cycle is absent in the periodogram of the reconstructed components of the seismic activity during the "reference" period. This is a clear indication of the reservoir-induced character of the seismicity around the Enguri dam