48 research outputs found

    Wettability Inversion of Aluminum-Magnesium Alloy Surfaces

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    The paper presents the experimental results on the use of low-temperature heating to reduce time of wetting inversion (from superhydrophilicity to hydrophobicity) of aluminum-magnesium alloy surfaces textured by laser radiation. Stable growth of the contact angle to 137.3-144.2° after heating surfaces (wettability properties deteriorate) was recorded. Wetting inversion from superhydrophilicity to hydrophobicity occurs in 2-3 hours of low-temperature heating of textured samples. The wettability inversion time depends on the type of texture. A significant increase in carbon content of elemental composition of the near-surface layer of samples after their low-temperature heating was registered

    Comparison of a ceiling-mounted 3D flat panel detector vs. conventional intraoperative 2D fluoroscopy in plate osteosynthesis of distal radius fractures with volar locking plate systems

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    Methods Using a common volar approach on 12 cadaver forearms, total intraarticular distal radius fractures were induced, manually reduced and internally fixated with a 2.4 distal radius locking compression plate. 2D (anterior-posterior and lateral) and 3D (rotational) fluoroscopic images were taken as well as computed tomographies. Fluoroscopic images, Cone Beam CT (CBCT), 360° rotating sequences (so called "Movies") and CT scans were co-evaluated by a specialist orthopedic surgeon and a specialist radiologist regarding quality of fracture reduction, position of plate, position of the three distal locking screws and position of the three diaphyseal screws. In reference to gold standard CT, sensitivity and specifity were analyzed. Results "Movie" showed highest sensitivity for detection of insufficient fracture reduction (88%). Sensitivity for detection of incorrect position of plate was 100% for CBCT and 90% for "Movie." For intraarticular position of screws, 2D fluoroscopy and CBCT showed highest sensitivity and specifity (100 and 91%, respectively). Regarding detection of only marginal intraarticular position of screws, sensitivity and specifity of 2D fluoroscopy reached 100% (CBCT: 100 and 83%). "Movie" showed highest sensitivity for detection of overlapping position of screws (100%). When it comes to specifity, CBCT achieved 100%. Regarding detection of only marginal overlapping position of screws, 2D fluoroscopy and "Movie" showed highest sensitivity (100%). CBCT achieved highest specifity (100%). Conclusion As for assessment of quality of fracture reduction and detection of incorrect position of plate as well as overlapping position of the three diaphyseal screws CBCT and "Movie" are comparable to CT - especially when combined. Particularly sensitivity is high compared to standard 2D fluoroscopy

    Funding Era Free Speech Theory: Applying Traditional Speech Protection to the Regulation of Anonymous Cyberspace

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    Abstract Background Blunt trauma is the most frequent mechanism of injury in multiple trauma, commonly resulting from road traffic collisions or falls. Two of the most frequent injuries in patients with multiple trauma are chest trauma and extremity fracture. Several trauma mouse models combine chest trauma and head injury, but no trauma mouse model to date includes the combination of long bone fractures and chest trauma. Outcome is essentially determined by the combination of these injuries. In this study, we attempted to establish a reproducible novel multiple trauma model in mice that combines blunt trauma, major injuries and simple practicability. Methods Ninety-six male C57BL/6 N mice (n = 8/group) were subjected to trauma for isolated femur fracture and a combination of femur fracture and chest injury. Serum samples of mice were obtained by heart puncture at defined time points of 0 h (hour), 6 h, 12 h, 24 h, 3 d (days), and 7 d. Results A tendency toward reduced weight and temperature was observed at 24 h after chest trauma and femur fracture. Blood analyses revealed a decrease in hemoglobin during the first 24 h after trauma. Some animals were killed by heart puncture immediately after chest contusion; these animals showed the most severe lung contusion and hemorrhage. The extent of structural lung injury varied in different mice but was evident in all animals. Representative H&E-stained (Haematoxylin and Eosin-stained) paraffin lung sections of mice with multiple trauma revealed hemorrhage and an inflammatory immune response. Plasma samples of mice with chest trauma and femur fracture showed an up-regulation of IL-1β (Interleukin-1β), IL-6, IL-10, IL-12p70 and TNF-α (Tumor necrosis factor- α) compared with the control group. Mice with femur fracture and chest trauma showed a significant up-regulation of IL-6 compared to group with isolated femur fracture. Conclusions The multiple trauma mouse model comprising chest trauma and femur fracture enables many analogies to clinical cases of multiple trauma in humans and demonstrates associated characteristic clinical and pathophysiological changes. This model is easy to perform, is economical and can be used for further research examining specific immunological questions

    Properties of nickel-phosphorous coatings codeposited by the electroless and electrochemical plating process

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    At present, despite numerous studies and practical application, the process of chemical nickel plating remains imperfect. The low nickel deposition rate, the high consumption of the solution components, and the complexity of the deposition process do not contribute to the widespread use of chemical nickel plating. At the same time, chemically deposited coatings are significantly different from the electrochemical: they possess valuable properties. In the paper, the intensification method of chemical nickel plating considered through the use of the co-deposition process with chemical and electrochemical methods. The co-deposition was carried out in an acidic electrolyte solution on an aluminum plate with the stationary potential shift from - 0.01 to - 0.25 V with the use of three electrode system. The presented technique of intensification due to the combination of nickel deposition processes by chemical and electrochemical methods is able to increase the deposition rate of the coatings, and also allows influencing their composition and mechanical properties

    Does the time of the day affect multiple trauma care in hospitals? A retrospective analysis of data from the TraumaRegister DGU®

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    Results Fewer patients were admitted during the night (6.00 pm-11.59 pm: 18.8% of the patients, 0.00-5.59 am: 4.6% of the patients) than during the day. Patients who arrived between 0.00 am-5.59 am were younger (49.4 ± 22.8 years) and had a higher injury severity score (ISS) (21.4 ± 11.5) and lower Glasgow Coma Scale (GCS) score (11.6 ± 4.4) than those admitted during the day (12.00 pm-05.59 pm; age: 55.3 ± 21.6 years, ISS: 20.6 ± 11.4, GCS: 12.6 ± 4.0). Time in the trauma department and time to an emergency operation were only marginally different. Time to imaging was slightly prolonged during the night (0.00 am-5.59 am: X-ray 16.2 ± 19.8 min; CT scan 24.3 ± 18.1 min versus 12.00 pm- 5.59 pm: X-ray 15.4 ± 19.7 min; CT scan 22.5 ± 17.8 min), but the delay did not affect the outcome. The outcome was also not affected by level of the trauma center. There was no relevant difference in the Revised Injury Severity Classification II (RISC II) score or mortality rate between patients admitted during the day and at night. There were no differences in RISC II scores or mortality rates according to time period. Admission at night was not a predictor of a higher mortality rate. Conclusion The patient population and injury severity vary between the day and night with regard to age, injury pattern and trauma mechanism. Despite the differences in these factors, arrival at night did not have a negative effect on the outcome

    Ontogenetic conflicts and rank reversals in two Mediterranean oak species: Implications for coexistence

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    In heterogeneous environments, species segregate spatially in response to selective abiotic and biotic filters occurring throughout plant ontogeny. Ontogenetic conflicts in recruitment may lead to spatially discordant patterns of regeneration among microhabitats with different plant cover. In addition, species differing in seed size may be subjected to opposing ecological and evolutionary pressures throughout the life cycle of the plant. We used a multi-stage demographic approach aimed at characterizing the main stage-specific probabilities of recruitment (seed survival, seed germination, seedling emergence and survival during the first 3years of life) in two Mediterranean oak species coexisting at southern Spain. We calibrated linear and nonlinear likelihood models for each of these consecutive life history stages and calculated overall probabilities of recruitment along a wide range of plant cover and seed size variation. Seed predation and seedling mortality over the dry season were the most limiting processes for the two studied oak species. However, species ranking diverged substantially through the life history stages considered in this study due to different ontogenetic trends among species. At the intraspecific level, recruitment-driving processes during the seed and the seedling stages showed opposing tendencies along the explored range of plant cover and seed size. Thus, small-sized acorns and open areas were favoured for the seed stage, whereas large acorns and dense microhabitats did for the seedling stage. The existence of opposing selective pressures on seed mass and their differential influence on the two studied oak species determined the occurrence of species-specific optimal seed sizes (small acorns for Quercus canariensis vs. acorns of large or intermediate size for Quercus suber). The spatial patterns predicted by our overall-recruitment models provided some evidence of regeneration niche partitioning in the two coexisting oak species, supporting their current distribution patterns as saplings and adults at the study area. Synthesis. We conclude that within- and among-species differences through plant ontogeny, arising from species differential response to microhabitat heterogeneity and seed size variation, could be of great importance for oak species niche segregation, driving stand dynamics and spatial pattern distribution along the landscape. The information provided by this study could be also applied to optimize management and restoration programmes since it has enabled us to identify the most favourable conditions and traits for recruitment in oak species that exhibit serious constraints for natural regeneration.This study was supported by a JAE-doc—contract to IMPR, by the Spanish MEC projects Heteromed (REN2002-4041-C02-02), Dinamed (CGL2005-5830-C03-01) and Interbos (CGL2008-04503-C03-01), the Andalusian PE2010-RNM-5782 project, and by European FEDER funds. This research is part of the Globimed (http:// www.globimed.net) network in forest ecology.Peer Reviewe

    УЯЗВИМОСТИ ADS-B

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    В данном исследовании рассмотрим более детально, как работают системы управления воздушными потоками старого и нового по-коления, а также представим найденные во время его исследования уязвимости и наиболее серьезные риски, связанные с ними. Авиатехнологии находятся на границе нового технического прорыва, и так, как это уже случилось со смартфонами и сетями мобильной связи примерно 5-10 лет назад, новые технологии приводят к новым проблемам. На этот раз – куда более опасным

    Positron annihilation technique in hydrogen storage materials

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    The feasibility of using the positron annihilation methods is discussed. Two main methods of electron positron annihilation - positron annihilation lifetime spectroscopy and coincidence Doppler broadening are used to characterize the materials - hydrogen accumulators
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