214 research outputs found

    Full State Feedback of DC-Motor Position and Speed Control Using LQR and Kalman Filter

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    DC motors are used in various industrial, robotic and motion control applications, and generally angular position and speed are used as the main control variables. This paper presents the design of an LQR controller with a Kalman Filter (KF) for state estimation during position and speed control of a DC motor. The proposed controller is evaluated for low and high speed reference profiles to demonstrate its efficiency in different types of applications. This approach is compared with the classical control method using a PID controller. From the results, it is observed that the settling time of the LQR-KF method is less, being 30% more efficient than the PID. In addition, the use of LQR provides an optimal state feedback control that minimizes the quadratic state error and control effort. The experimental results demonstrate the feasibility of the controller design for high precision applications. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG

    Design, Assembly and Working Modes of Spherical 3-RRR Coaxial Parallel Robot

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    Design, configuration and operation modes of spherical 3-_RRR coaxial parallel robot were performed. A mathematical analysis of the robot was made, which consists of inverse and forward kinematic using geometric and numerical methods respectively, using MATLAB environment. Based on the above, eight possible operation and configuration modes were derived. The proposed approach demonstrates that a unique solution for the specific configuration and operation mode of a coaxial robot can be calculated. Moreover, mechanical design of the robot prototype was performed in the SolidWorks design program presented in detail for experimental verification of the performed numerical and simulation analyses. Results obtained from this work can be implemented in the development of real time orientation control systems for coaxial robots. As future works, an analysis of singularities, performance and dynamic will be carried out. © 2021 IEEE

    Worldwide Disparities in Recovery of Cardiac Testing 1 Year Into COVID-19

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    BACKGROUND The extent to which health care systems have adapted to the COVID-19 pandemic to provide necessary cardiac diagnostic services is unknown. OBJECTIVES The aim of this study was to determine the impact of the pandemic on cardiac testing practices, volumes and types of diagnostic services, and perceived psychological stress to health care providers worldwide. METHODS The International Atomic Energy Agency conducted a worldwide survey assessing alterations from baseline in cardiovascular diagnostic care at the pandemic's onset and 1 year later. Multivariable regression was used to determine factors associated with procedure volume recovery. RESULTS Surveys were submitted from 669 centers in 107 countries. Worldwide reduction in cardiac procedure volumes of 64% from March 2019 to April 2020 recovered by April 2021 in high- and upper middle-income countries (recovery rates of 108% and 99%) but remained depressed in lower middle- and low-income countries (46% and 30% recovery). Although stress testing was used 12% less frequently in 2021 than in 2019, coronary computed tomographic angiography was used 14% more, a trend also seen for other advanced cardiac imaging modalities (positron emission tomography and magnetic resonance; 22%-25% increases). Pandemic-related psychological stress was estimated to have affected nearly 40% of staff, impacting patient care at 78% of sites. In multivariable regression, only lower-income status and physicians' psychological stress were significant in predicting recovery of cardiac testing. CONCLUSIONS Cardiac diagnostic testing has yet to recover to prepandemic levels in lower-income countries. Worldwide, the decrease in standard stress testing is offset by greater use of advanced cardiac imaging modalities. Pandemic-related psychological stress among providers is widespread and associated with poor recovery of cardiac testing

    923-3 Fluosol Reduces Myocardial Reperfusion Injury by Prolonged Suppression of Neutrophils by its Detergent Component (RheothRx) and not by Enhancing O2Delivery

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    Fluosol, a complex mixture of O2carrying perfluorocarbons (PFCs) emulsified by the detergent pluronic F-68 and a variety of lipids, significantly reduces myocardial reperfusion injury (RI) in animals and humans as shown in some initial clinical trials. Potential mechanisms for Fluosol include enhanced O2delivery to the reperfused tissue and modulation of various neutrophil (PMNs) functions. Recent studies in dogs and man demonstrate the same beneficial effect for treatment of Rl with the detergent component alone, RheothRx, which is currently undergoing clinical trials. We have shown that the effect of Fluosol on PMNs is related to this detergent. However, prolonged infusion (48 hrs) of detergent is required to reduce Rl to the same extent as Fluosol given over only 1 hr. Possible mechanisms for the beneficial effects of Fluosol (O2delivery vs effects on PMNs) were investigated in a model of regional ischemia utilizing rabbits undergoing 30mins of circumflex occlusion and 48 hrs of reperfusion. Infarct size (area of necrosis, AN) was determined histologically and expressed as percent of risk region (area at risk, AR). Animals received Fluosol (30cc/kg) with or without O2or saline over the first 60mins of reperfusion. AR was similar in all groups. (Mean±SEM of AN/AR (%), n=11 for all groups). The treatment with Fluosol with or without O2(44±3 and 40;±3, respectively) was significantly (p<0.05) reduced compared to control (63±4). Another group received F-I08, a larger size pluronic detergent found to be 2.5-fold more potent in suppressing PMN function in vitrocompared to F-68, during the first 3 hrs of reperfusion. This treatment did not alter the infarct size (63±5). RheothRx was found to form 4 nm micelles in solution whereas Fluosol formed particles approximately 100 times larger. Similar sized particles were formed by substituting the perfluorocarbons with mineral oil. The in vitroactivity of this pluronic/mineral oil micelle on PMN function was similar to Fluosol. Infusion of these larger oil micelles was tolerated by rabbits and used in further infarct studies.ConclusionsThese studies suggest that (1) reduction of RI by Fluosol is not due to enhanced O2delivery by the PFCs to reperfused myocardium and (2) since the Fluosol emulsion markedly reduces the clearance of the detergent F-68 (t½: Fluosol ≅ 8 hrs vs RheothRx ≅ 1.5 hrs). prolonged PMN suppression rather than potency of suppression is the mechanism whereby Fluosol ameliorates RI. Fluosol's clinical efficacy may be enhanced by prolonging its infusion to ensure an adequate blood level to suppress PMN function beyond the time of reperfusion injury. RheothRx's clinical usefulness may be facilitated by decreasing its renal clearance by delivering larger micelles of the detergent in order to produce prolonged PMN suppression with a shorter infusion time

    Fauna asociada a la palma de vino <i>Attalea butyracea</i> (Mutis ex L.f.) Wess.Boer (1988) (Arecales: Arecaceae) en un agroecosistema de Galeras, Sucre, Colombia

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    Se estudió la fauna asociada a Attalea butyracea en un agroecosistema de Galeras, Sucre, Colombia. Se efectuaron muestreos en junio de 2016 en la nca Mi Ranchito, donde se revisaron 42 palmas. De las palmas se extrajeron artrópodos y se buscaron vertebrados. Posteriormente, el material se identi có y se registraron 13 órdenes, con las siguientes frecuencias de aparición y abundancias: Hymenoptera (100 %; 232), Coleoptera (97,62 %; 240), Araneae (95,24 %; 169), Blattodea (88,09 %; 143), Hemiptera (88,09 %; 82), Amblypygi (85,71 %; 166), Polydesmida (78,57 %; 103), Lepidoptera (73,81 %; 69), Archaeognatha (71,43 %; 81), Orthoptera (69,04 %; 31), Scorpiones (69,04 %; 30), Ixodida (66,66 %; 34) y Opiliones (66,66 %; 57). Se identi caron las siguientes 18 especies: Arachnida: Charinus sp., Hapalopus sp., Phrynus barbadensis y Tityus tayrona; Insecta: Phileurus sp., Rhodnius pallescens y Triatoma dimidiata; Amphibia: Elachistocleis pearsei y Rhinella humboldti; Sauropsida: Bothrops asper, Cnemidophorus lemniscatus, Gonatodes albogularis, Gymnophthalmus speciosus y Mabuya sp.; y Mammalia: Artibeus lituratus, Didelphis marsupialis, Molossus sp. y Mus musculus. En conclusión, la palma de vino, por su arquitectura, funciona como microambiente para artrópodos y vertebrados pequeños; es utilizada como vivienda, dormitorio o refugio ocasional, lo que hace de esta planta un sitio importante en las interacciones de animales silvestres

    Fauna asociada a la palma de vino Attalea butyracea (Mutis ex L.f.) Wess.Boer (1988) (Arecales: Arecaceae) en un agroecosistema de Galeras, Sucre, Colombia

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    The fauna associated with Attalea butyracea was studied in an agroecosystem of Galeras, Sucre, Colombia. Samplings were carried out during June 2016 in the farm Mi Ranchito, where 42 palms were checked. From the palms, arthropods were extracted and vertebrates were searched for. Subsequently, the material was identified and 13 orders were recorded with appearance frequencies and abundances as follows: Hymenoptera (100%; 232), Coleoptera (97.62%; 240), Araneae (95.24%; 169), Blattodea (88.09%; 143), Hemiptera (88.09%; 82), Amblypygi (85.71%; 166), Polydesmida (78.57%; 103), Lepidoptera (73.81%; 69), Archaeognatha (71.43%; 81), Orthoptera (69.04%; 31), Scorpiones (69.04%; 30), Ixodida (66.66%; 34) and Opiliones (66.66%; 57). Eighteen species were identified as follows: Arachnida: Charinus sp., Hapalopus sp., Phrynus barbadensis and Tityus tayrona; Insecta: Phileurus sp., Rhodnius pallescens and Triatoma dimidiata; Amphibia: Elachistocleis pearsei and Rhinella humboldti; Sauropsida: Bothrops asper, Cnemidophorus lemniscatus, Gonatodes albogularis, Gymnophthalmus speciosus and Mabuya sp.; and Mammalia: Artibeus lituratus, Didelphis marsupialis, Molossus sp. and Mus musculus. In conclusion, the Wine Palm functions as a microenvironment for arthropods and small vertebrates due to its architecture; it is used as a dwelling, dormitory or occasional refuge, making it an important site for interactions of wild animals.Se estudió la fauna asociada a Attalea butyracea en un agroecosistema de Galeras, Sucre, Colombia. Se efectuaron muestreos en junio de 2016 en la nca Mi Ranchito, donde se revisaron 42 palmas. De las palmas se extrajeron artrópodos y se buscaron vertebrados. Posteriormente, el material se identi có y se registraron 13 órdenes, con las siguientes frecuencias de aparición y abundancias: Hymenoptera (100 %; 232), Coleoptera (97,62 %; 240), Araneae (95,24 %; 169), Blattodea (88,09 %; 143), Hemiptera (88,09 %; 82), Amblypygi (85,71 %; 166), Polydesmida (78,57 %; 103), Lepidoptera (73,81 %; 69), Archaeognatha (71,43 %; 81), Orthoptera (69,04 %; 31), Scorpiones (69,04 %; 30), Ixodida (66,66 %; 34) y Opiliones (66,66 %; 57). Se identi caron las siguientes 18 especies: Arachnida: Charinus sp., Hapalopus sp., Phrynus barbadensis y Tityus tayrona; Insecta: Phileurus sp., Rhodnius pallescens y Triatoma dimidiata; Amphibia: Elachistocleis pearsei y Rhinella humboldti; Sauropsida: Bothrops asper, Cnemidophorus lemniscatus, Gonatodes albogularis, Gymnophthalmus speciosus y Mabuya sp.; y Mammalia: Artibeus lituratus, Didelphis marsupialis, Molossus sp. y Mus musculus. En conclusión, la palma de vino, por su arquitectura, funciona como microambiente para artrópodos y vertebrados pequeños; es utilizada como vivienda, dormitorio o refugio ocasional, lo que hace de esta planta un sitio importante en las interacciones de animales silvestres

    Barriers to medication counselling for people with mental health disorders : A six country study

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    Provision of medication information may improve adherence and prevent medication related problems. People with mental health disorders commonly receive less medication counselling from pharmacists than people with other common long term and persistent disorders. Objective: The objective of this study was to compare and contrast barriers pharmacy students perceive toward providing medication counselling for people with mental health disorders in Australia, Belgium, Estonia, Finland, India and Latvia. Methods: Barriers identified by third-year pharmacy students as part of the International Pharmacy Students' Health Survey were content analysed using a directed approach. Students' responses were categorised as pharmacist related, patient related, health-system related, or social or cultural related. Quantitative data were analysed using SPSS version 14.0. Results: Survey instruments were returned by 649 students. Of the respondents, 480 identified one or more barriers to medication counselling for people with mental health disorders. Patient related factors accounted for between 25.3% and 36.2% of barriers identified by the pharmacy students. Pharmacist related factors accounted for between 17.6% and 45.1% of the barriers identified by the pharmacy students. Students in India were more likely to attribute barriers to pharmacist and social and cultural related factors, and less likely to healthsystem related factors, than students studying in other countries. Conclusion: The nature of barriers identified by pharmacy students differed according to the country in which they studied. Undergraduate and postgraduate pharmacy education programs may need to be amended to address common misconceptions among pharmacy students.publishersversionPeer reviewe

    Case report: Two unexpected cases of DGUOK-related mitochondrial DNA depletion syndrome presenting with hyperinsulinemic hypoglycemia

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    Timely diagnosis of persistent neonatal hypoglycemia is critical to prevent neurological sequelae, but diagnosis is complicated by the heterogenicity of the causes. We discuss two cases at separate institutions in which clinical management was fundamentally altered by the results of molecular genetic testing. In both patients, critical samples demonstrated hypoketotic hypoglycemia and a partial glycemic response to glucagon stimulation, thereby suggesting hyperinsulinism (HI). However, due to rapid genetic testing, both patients were found to have deoxyguanosine kinase (DGUOK)-related mitochondrial DNA depletion syndrome, an unexpected diagnosis. Patients with this disease typically present with either hepatocerebral disease in the neonatal period or isolated hepatic failure in infancy. The characteristic features involved in the hepatocerebral form of the disease include lactic acidosis, hypoglycemia, cholestasis, progressive liver failure, and increasing neurologic dysfunction. Those with isolated liver involvement experience hepatomegaly, cholestasis, and liver failure. Although liver transplantation is considered, research has demonstrated that for patients with DGUOK-related mitochondrial DNA depletion syndrome and neurologic symptoms, early demise occurs. Our report advocates for the prompt initiation of genetic testing in patients presenting with persistent neonatal hypoglycemia and for the incorporation of mitochondrial DNA depletion syndromes in the differential diagnosis of HI
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