Thunderstorm ground enhancements: Multivariate analysis of 12 years of observations

We present a survey of more than a half-thousand thunderstorm ground enhancements (TGEs, fluxes of electrons, and gamma rays associated with thunderstorms) registered in 2008–2022 at Aragats space environmental center (ASEC). We analyze correlations between various measured parameters characterizing TGEs measured on Aragats. Two special cases of TGE events are considered: one, terminated by nearby lightning flashes, and another one—with a sufficiently large ratio of electrons to gamma rays. On the basis of the analysis, we summarize the most important results obtained during 12 years of TGE study, which include the following statements: (i) TGEs originated from multiple relativistic runaway electron avalanches starting with seed electrons from the ambient population of cosmic rays, which enter an extended region of the electric field with strength exceeding the critical value; (ii) quite frequently, TGEs occur prior to lightning flashes and are terminated by them; (iii) the energy spectra of avalanche electrons observed on Aragats indicate that the strong electric field region can extend very low above the ground covering a large area on the earth’s surface

Heat Treated NiP–SiC Composite Coatings: Elaboration and Tribocorrosion Behaviour in NaCl Solution

Tribocorrosion behaviour of heat-treated NiP and NiP–SiC composite coatings was investigated in a 0.6 M NaCl solution. The tribocorrosion tests were performed in a linear sliding tribometer with an electrochemical cell interface. It was analyzed the influence of SiC particles dispersion in the NiP matrix on current density developed, on coefficient of friction and on wear volume loss. The results showed that NiP–SiC composite coatings had a lower wear volume loss compared to NiP coatings. However, the incorporation of SiC particles into the metallic matrix affects the current density developed by the system during the tribocorrosion test. It was verified that not only the volume of co-deposited particles (SiC vol.%) but also the number of SiC particles per coating area unit (and consequently the SiC particles size) have made influence on the tribocorrosion behaviour of NiP–SiC composite coatings

Improved study of a possible Theta+ production in the pp -> p K0 sigma+ reaction with the COSY-TOF spectrometer

The pp -> p K0 Sigma+ reaction was investigated with the TOF spectrometer at COSY at 3.059 GeV/c incident beam momentum. The main objective was to clarify whether or not a narrow exotic S = +1 resnance, the Theta+ pentaquark, is populated at 1.53 GeV/c2 in the K0 p subsystem with a data sample of much higher statistical significance compared to the previously reported data in this channel. An analysis of these data does not confirm the existence of the Theta+ pentaquark. This is expressed as an upper limit for the cross section sigma (pp -> p K0 Sigma+) < 0.15 microbarn at the 95 percent confidence level.Comment: 11 pages, 5 figure

Удосконалена система хірургічного лікування постраждалих з пошкодженнями таза та тазових органів при політравмі

Мета. Оцінити ефективність удосконаленої системи хірургічного лікування постраждалих з пошкодженнями таза та тазових органів при політравмі. Матеріали і методи. В основу дослідження покладено клінічні спостереження 406 постраждалих з нестабільними пошкодженнями таза (НПТ) при політравмі (оцінка тяжкості за шкалою ISS 17 балів і вище).  НПТ у 98 (24,1%) постраждалих з політравмою були поєднані з пошкодженнями тазових органів. Сформовано дві клінічні групи: основну – 137 (33,7%) постраждалих, із них у 37 (27,0%) НПТ були поєднані з пошкодженнями тазових органів, і контрольну – 269 (66,3%) постраждалих, із них у 61 (22,7%) постраждалого НПТ були поєднані з пошкодженнями тазових органів. У постраждалих основної групи застосована диференційована хірургічна тактика лікування, яка базувалась на оцінці тяжкості травми, прогнозі перебігу травматичної хвороби (ТХ) у залежності від її періодів, а також запропонованих сучасних методах діагностики і лікування пошкоджень таза й інших анатомічних ділянок (АД). Для лікування пацієнтів контрольної групи застосовували хірургічну тактику згідно з тимчасовими галузевими уніфікованими стандартами медичних технологій діагностично-лікувального процесу стаціонарної допомоги дорослому населенню в лікувально-профілактичних закладах України, затвердженими наказом МОЗ України №226 від 27 липня 1998 р. Результати. При травмі сечового міхура у 47 (83,9%) постраждалих зашили розрив стінки міхура з епіцистостомією і катетеризацією міхура катетером Фолея. При травмі уретри епіцистостомію поєднували з шинуванням уретри катетером у 27 (81,8%) хворих. У 3 пацієнтів основної групи використали первинний шов уретри в гострому періоді ТХ. У всіх пацієнтів з пошкодженнями прямої кишки накладали дводульну сигмостому. Операції на внутрішніх статевих органах виконані 3 (3,2%) постраждалим. Усього на тазових органах у гострому періоді ТХ виконано 94 оперативних втручання різної складності. Висновки. При політравмі переломи кісток таза були поєднані з травмою тазових органів у 24,1% постраждалих. Поєднане пошкодження тазових органів (за винятком пошкоджень прямої кишки) не є протипоказанням до виконання внутрішнього або комбінованого металоостеосинтезу нестабільного тазового кільця у постраждалих з політравмою в ранньому та пізньому періодах ТХ

The Observed Correlations for the Strange Multibaryon States in Systems with Λ\Lambda-Hyperon from pa Collision at Momentum of 10 Gev/cc

he observed well-known resonances $\Sigma^0$ $\Sigma^{*+}$(1385) and $K^{*\pm}$(892) from PDG are good tests of this method. Exotic strange multibaryon states have been observed in the effective mass spectra of: $\Lambda \pi^{\pm}$,$\Lambda \gamma$, $\Lambda p$, $\Lambda p p$ subsystems. The mean value of mass for $\Sigma^{*-}(1385)$ resonance is shifted till mass of 1370 MeV/$c^2$ and width is two times larger than the same value from PDG. Such kind of behavior for width and invariant mass of $\Sigma^{*-}(1385)$ resonance is interpreted as extensive contribution from stopped $\Xi^-\to\Lambda\pi^-$ and medium effect with invariant mass. The mean value of mass for $\Sigma^{*+}(1385)$ from secondary interactions is also shifted till mass of 1370 MeV/$c^2$. The width of $\Sigma^0$ is $\approx$ 2 times larger than the experimental error. There are enhancement production for all observed hyperons.Comment: 4 pages, 6 figures, XXIst Rencontres de Blois "Windows on the Universe " Blois, France June 21st - June 26th, 200

Surgical treatment of wounded persons with complicated thoracic damages

Objective. To improve the results of complex surgical treatment of wounded and injured persons with thoracic trauma, complicated by bronchopleural fistulas, pleural empyema and defects in the thoracic wall soft tissues, basing on introduction of the proposed procedure of vacuum therapy in combination with bronchoscopic obturation of certain bronchus. Materials and methods. Analysis of results of the complex surgical help delivery for 54 wounded persons with defects of the thoracic wall soft tissues, broncho-pleural fistulas and pleural empyema, caused by the combat thoracic trauma, on ІІІ and ІV levels of medical support while conduction of the Antiterrorist operation/Operation of the Joined Forces (the main group) and 73 injured persons with thoracic trauma of the peace period (the comparison group) in the 2014 - 2019 yrs period was conducted. Results. Improvement of complex surgical treatment of the wounded and damaged persons with thoracic trauma and defects of the thoracic wall soft tissues have permitted to reduce the complications frequency by 6.7%, and lethality - by 9.2% in the main group. Conclusion. There was proposed a procedure of vacuum therapy, ultrasound cavitation together with bronchoscopic bronchial obturation for its fistula, which have proved its efficacy in complex surgical treatment of severely wounded persons with the gun-shot thoracic damages and presence of combination of pleural empyema, bronchial fistula and defects of soft tissues

C-reactive protein in the very early phase of acute ischemic stroke: association with poor outcome and death

Acute ischemic stroke may trigger an inflammatory response that leads to increased levels of C-reactive protein (CRP). High levels of CRP may be associated with poor outcome because they reflect either an inflammatory reaction or tissue damage. We evaluated the prognostic value of CRP within 12 h of onset of ischemic stroke. Levels of CRP were routinely obtained within 12 h of symptom onset in 561 patients with ischemic stroke. CRP values were dichotomized as <7 or ≥7 mg/L. The full range of CRP values was used to detect a possible level-risk relationship. We studied the relation between CRP values and poor outcome (modified Rankin Scale score >2) or death at 3 months. A multiple logistic regression model was applied to adjust for age, sex, NIHSS score, current cigarette smoking, diabetes mellitus, hypertension, statin use, and stroke subtype. After adjustment for potential confounders, patients with CRP levels ≥7 mg/L had a significantly increased risk of poor outcome (adjusted OR 1.6, 95% CI 1.1–2.4) or death (adjusted OR 1.7, 95% CI 1.0–2.9) at 3 months. In addition, the risk of poor outcome or death at 3 months increased with higher levels of CRP. CRP within 12 h of ischemic stroke is an independent prognostic factor of poor outcome at 3 months

Association of severe hypertension with pneumonia in elderly patients with acute ischemic stroke

Pneumonia is one of the most frequent complications in elderly patients with acute ischemic stroke. Although severe hypertension is often observed in the early phase of acute stroke, there are few studies of acute hypertension as a factor influencing the incidence of stroke-associated pneumonia (SAP) in elderly subjects with acute ischemic stroke. To assess the association of acute phase blood-pressure elevation with the incidence of SAP, we compared 10 elderly patients with acute ischemic stroke complicated with severe hypertension (⩾200/120 mm Hg) with 43 patients with moderate hypertension (160–199/100–119 mm Hg), as well as with 65 control normotensive or mildly hypertensive (<160/100 mm Hg) controls on admission. Data were collected on known risk factors, type of ischemic stroke and underlying chronic conditions. The significance of differences in risk factors was analyzed using univariate and multivariate comparisons of 38 SAP cases and others, 8 SAP death cases and others, and 28 patients with poor outcome associated with in-hospital death or artificial feeding at discharge and others. After adjustment for potential confounding factors, the relative risk estimates for SAP, SAP death and poor outcome were 2.83 (95% confidence interval 1.14–7.05), 5.20 (1.01–26.8) and 6.84 (1.32–35.4), respectively, for severe hypertension relative to normotensive or mildly hypertensive controls. We conclude that severe hypertension on admission is an independent predictive factor for SAP in elderly patients with acute ischemic stroke