3,165 research outputs found
Experimental Study of the Superconducting Microstrip Antenna as a Protective Device of the Receiver From Electromagnetic Damage
The paper presents the results of experimental studies of a superconducting protective antenna, which consists of a high-temperature film deposited by a magnetron or a laser beam on a substrate. The work is carried out:- analysis of the selection criteria for the substrate type (Al2O3, Y2O3, SrTiO3, MgO) and the method for depositing a high-temperature superconducting film (HTSF) on its surface – YBaCuO- analysis of the methods of making contacts, which allow to reduce losses when passing a signal from the superconducting microstrip antenna to the waveguide path.The aim of this article is determination of the parameters of a prototype sample of a microstrip antenna device made from HTSF: transient characteristics of high-temperature superconductors, HTSF impulsive characteristics, recovery time of the superconducting state after the action of a powerful pulse on the protective device, the amplitude-frequency characteristics of the protective device in the superconducting state. This will allow to evaluate the possibility of using a microstrip antenna device made from high-temperature superconductors to protect the receiving systems from electromagnetic damage. The absence of a unified theory of high-temperature superconductivity leads to the need to select an analytical form of the functions of the amplitude-frequency characteristics of superconducting protection, and for this mathematical models are used in the programs "APPROX", "MathCAD14.0". The reliability of the obtained results of mathematical modeling of the processes of protection and recovery of the superconducting state after electromagnetic shock are confirmed in the course of experimental studies (an error of 0.15%)
Lack of prophylaxis before the onset of acute venous thromboembolism among hospitalized cancer patients: the SWIss Venous ThromboEmbolism Registry (SWIVTER)
Background: Venous thromboembolism (VTE) prophylaxis remains underutilized, particularly in cancer patients. We explored clinical predictors of prophylaxis in hospitalized cancer patients before the onset of acute VTE. Methods: In the SWiss Venous ThromboEmbolism Registry, 257 cancer patients (61 ± 15 years) with acute VTE and prior hospitalization for acute medical illness or surgery within 30 days (91% were at high risk with Geneva VTE risk score ≥3) were enrolled. Results: Overall, 153 (60%) patients received prophylaxis (49% pharmacological and 21% mechanical) before the onset of acute VTE. Outpatient status at the time of VTE diagnosis [odds ratio (OR) 0.31, 95% confidence interval (CI) 0.18-0.53], ongoing chemotherapy (OR 0.51, 95% CI 0.31-0.85), and recent chemotherapy (OR 0.53, 95% CI 0.32-0.88) were univariately associated with the absence of VTE prophylaxis. In multivariate analysis, intensive care unit admission within 30 days (OR 7.02, 95% CI 2.38-20.64), prior deep vein thrombosis (OR 3.48, 95% CI 2.14-5.64), surgery within 30 days (OR 2.43, 95% CI 1.19-4.99), bed rest >3 days (OR 2.02, 95% CI 1.08-3.78), and outpatient status (OR 0.38, 95% CI 0.19-0.76) remained the only independent predictors of thromboprophylaxis. Conclusions: Although most hospitalized cancer patients were at high risk, 40% did not receive any prophylaxis before the onset of acute VTE. There is a need to improve thromboprophylaxis in cancer patients, particularly in the presence of recent or ongoing chemotherap
Gefäßmedizin heute: Die Berner Sicht
Zusammenfassung: Die moderne Behandlung von Gefäßpatienten stellt eine reizvolle und anspruchsvolle Aufgabe dar, welche aufgrund der Komplexität und der Breite des Spektrums heute in interdisziplinären Gefäßzentren durchgeführt werden sollte. Die enge Zusammenarbeit zwischen Gefäßchirurgen und Angiologen hat an der Universität Bern eine lange Tradition. Der vorliegende Artikel legt die grundlegende Philosophie unserer gefäßchirurgisch-angiologischen Freundschaft und Zusammenarbeit dar und schildert deren Umsetzung im klinischen Allta
Use of biomarkers or echocardiography in pulmonary embolism: the Swiss Venous Thromboembolism Registry
Background: Cardiac biomarkers and echocardiography for assessing right ventricular function are recommended to risk stratify patients with acute non-massive pulmonary embolism (PE), but it remains unclear if these tests are performed systematically in daily practice. Design and methods: Overall, 587 patients with acute non-massive PE from 18 hospitals were enrolled in the Swiss Venous Thromboembolism Registry (SWIVTER): 178 (30%) neither had a biomarker test nor an echocardiographic evaluation, 196 (34%) had a biomarker test only, 47 (8%) had an echocardiogram only and 166 (28%) had both tests. Results: Among the 409 (70%) patients with biomarkers or echocardiography, 210 (51%) had at least one positive test and 67 (16%) had positive biomarkers and right ventricular dysfunction. The ICU admission rates were 5.1% without vs. 5.6% with testing (P = 0.78), and thrombolysis or embolectomy were performed in 2.8% vs. 4.9%, respectively (P = 0.25). In multivariate analysis, syncope [odds ratio (OR): 3.49, 95% confidence interval (CI): 1.20-10.15; P = 0.022], tachycardia (OR: 2.31, 95% CI: 1.37-3.91; P = 0.002) and increasing age (OR: 1.02; 95% CI: 1.01-1.04; P < 0.001) were associated with testing of cardiac risk; outpatient status at the time of PE diagnosis (OR: 2.24, 95% CI: 1.49-3.36; P < 0.001), cancer (OR: 1.81, 95% CI: 1.17-2.79; P = 0.008) and provoked PE (OR: 1.58, 95% CI: 1.05-2.40; P = 0.029) were associated with its absence. Conclusions: Although elderly patients and those with clinically severe PE were more likely to receive a biomarker test or an echocardiogram, these tools were used in only two-thirds of the patients with acute non-massive PE and rarely in combinatio
Differences in duration of anticoagulation after pulmonary embolism and deep vein thrombosis: Findings from the SWIss Venous ThromboEmbolism Registry (SWIVTER).
Although the two manifestations of venous thromboembolism (VTE), deep vein thrombosis (DVT) and pulmonary embolism (PE), vary considerably, the consensus guidelines recommend similar algorithms for therapeutic anticoagulation in both conditions. Real-world data assessing contemporary management strategies in PE and DVT alone may help tailoring future recommendations towards more individualized patient care.
In the present analysis, we compared demographics, comorbidities, treatment patterns, and clinical outcomes of PE versus DVT only among 2062 consecutive patients with confirmed VTE enrolled by 11 acute care hospitals between November 2012 and February 2015 in the SWIss Venous ThromboEmbolism Registry (SWIVTER).
Overall, 1246 (60 %) patients were diagnosed with PE. In comparison to DVT alone, PE patients were older (66 vs. 59 years; p < 0.001), more frequently had acute and chronic comorbidities, less frequently had prior VTE and hormone replacement, and were less often pregnant. VTE was considered similarly often provoked in patients with PE and DVT alone (33.8 % vs. 33.5 %; p = 0.88). Anticoagulation for an indefinite duration was more often prescribed to patients with PE than those with DVT alone (45.7 vs. 19.6 %; p < 0.001), and PE diagnosis was the strongest independent predictor of indefinite anticoagulation (OR 3.21; 95 % CI 2.55-4.06; p < 0.001). Diagnosis of PE was associated with both increased risk of 90-day mortality (HR 2.31, 95 % CI 1.44-3.71; p = 0.001) and major bleeding (HR 3.88, 95 % CI 1.63-9.22; p = 0.002).
Our analysis affirms differences in demographics, risk factors, and clinical outcomes of PE versus DVT alone. In routine clinical practice, duration of anticoagulation is being managed differently between the two manifestations of VTE, in contrast to recommendations of the current consensus guidelines
The relationship of organization Failure Modes and Effects Analysis with the safety quality for Supply Chain Risk Management
Abstract- Supply chain risk management (SCRM) is a key component of not only supply success but firm success as well. All Companies aim to achieve the highest level in quantity and quality of their products in the shortest time while preserving the safety of their workers and providing all appropriate conditions for them. Whereas many institutions spend a lot of money to implement international safety and quality standards in order to reach this goal, they continue to suffer from some failures on the level of worker safety and unstable product quality. The presence of the human factor necessarily means the possibility of errors, and these errors naturally have accumulations that may reach even the furthest point in the organization and this leads to an increased possibility of accidents and fluctuations in product quality and waste of time. In view of the common goals and similarities between the Failure Modes and Effects Analysis (FMEA) organization, supply chain risk management, and the effective pivotal role of the FMEA organization in extracting points of failure and errors at the FMEA organization and field levels. Linking them in a way that allows managers to explore errors in the least time possible to remedy its consequences. The relationship between the FMEA organization and product quality management aims to improve performance and improve product quality in the shortest possible time
Flow interactions with an aquatic macrophyte: a field study using stereoscopic particle image velocimetry
This paper reports the morphology of a natural patch of Ranunculus penicillatus and presents high-resolution measurements of flow velocities in its wake using a stereoscopic PIV field measurement system. The patch was 3.80 m long, 1.24 m wide and caused substantial changes to downstream mean velocities and turbulence. Vertical profiles of streamwise mean velocity were not logarithmic and flow was redirected under the positively buoyant canopy, enhancing vertical turbulent mixing in the wake and generating a large region where the velocity covariance u'w'
was positive. Turbulent kinetic energy was enhanced downstream from the patch lateral shear layer, but not at the centre of the wake. Spectra downstream from the patch showed that turbulence was neither dominated by fine-scale nor large-scale structures, likely due to the low energy of the flow conditions and lack of a developed vortex street within the measurement domain. Sedimentation was observed at the upstream end of the patch, but not underneath the floating canopy. The methods and results of this work will be useful for planning other in situ studies. Also, the reported data on macrophyte geometry and biometrics will assist with the design of more realistic replicas for use in laboratory studies
Soil patterns as a factor of crop heterogeneity
This paper examines the relationship between the heterogeneity of different crops in the Tula region of the Russian Federation based on vegetation observations during the period 2015-2020 with the mapping units of a large (scale 1:10,000) soil map. NDVI values calculated from Sentinel-2 satellite data were used as a measure of crop heterogeneit
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