Field Oriented Control of Multiphase Drives with Passive Fault-Tolerance

Multiphase machines provide continuous operation of the drive with no additional hardware in the event of one or more open-phase faults. This faulttolerant capability is highly appreciated by industry for security and economic reasons. However, the steadystate post-fault operation has only been feasible in previous works after the fault localization and control reconfiguration. Even though this is done at the software stage, the obligation to identify the faulty phases and store the modifications for every fault scenario adds further complexity. This work reveals that this software reconfiguration can be avoided if the field-oriented control (FOC) strategy is designed to satisfactorily handle pre- and post-fault situations. Experimental results confirm the capability to obtain suitable postfault operation without fault localization and control reconfiguration, thus achieving a passive/natural fault tolerance.Ministerio de Ciencia, Innovación y Universidades RTI2018-096151-B-I0

Knowledge, attitudes, perceptions and habits towards antibiotics dispensed without medical prescription: a qualitative study of Spanish pharmacists

Objective To investigate community pharmacists’ knowledge, attitudes, perceptions and habits with regard to antibiotic dispensing without medical prescription in Spain. Methods A qualitative research using focus group method (FG) in Galicia (north-west Spain). FG sessions were conducted in the presence of a moderator. A topic script was developed to lead the discussions, which were audiorecorded to facilitate data interpretation and transcription. Proceedings were transcribed by an independent researcher and interpreted by two researchers working independently. We used the Grounded Theory approach. Setting Community pharmacies in Galicia, region Norwest of Spain. Participants Thirty pharmacists agreed to participate in the study, and a total of five FG sessions were conducted with 2–11 pharmacists. We sought to ensure a high degree of heterogeneity in the composition of the groups to improve our study's external validity. Pharmacists’ participation had no gender or age restrictions, and an effort was made to form FGs with pharmacists who were both owners and non-owners, provided in all cases that they were Official Colleges of Pharmacists-registered community pharmacists. For the purpose of conducting FG discussions, the basic methodological principle of allowing groups to attain their ‘own structural identity’ was applied. Main outcome measurements Community pharmacists’ habits and knowledge with regard to antibiotics and identification of the attitudes and/or factors that influence antibiotic dispensing without medical prescription. Results Pharmacists attributed the problem of antibiotics dispensed without medical prescription and its relationship to antibiotic resistance to the following attitudes: external responsibility (doctors, dentists and the National Health Service (NHS)); acquiescence; indifference and lack of continuing education. Conclusions Despite being a problem, antibiotic dispensing without a medical prescription is still a common practice in community pharmacies in Galicia, Spain. This practice is attributed to acquiescence, indifference and lack of continuing education. The problem of resistance was ascribed to external responsibility, including that of patients, physicians, dentists and the NHS.S

Thematic Trends Around Gamification in MOOC: A Bibliometric Analysis

Currently, educational systems have assumed a relevant role in developing knowledge and strengthening skills in individuals, an aspect that has become a determining factor for the advancement of society. However, these systems present constant challenges, especially influenced by the advance in information and communication technologies, access to the Internet, and mobile devices, which implies transformations in the new paradigms of teaching and learning methodologies. In this scenario, gamification has been one of the strategies used within virtual learning environments such as MOOCs to increase student motivation in the development of courses. In the last decade, interest in this topic has been evidenced. Therefore, this study aims to identify the main research trends in studies on gamification in MOOCs in the last ten years. For this purpose, a bibliometric analysis was carried out using the Scopus database, from which 265 publications were obtained. The main actors (authors and journals) most cited and thematic trends were identified based on the recurrence of keywords. Among the findings, it was identified that researchers are interested in e-Learning, motivation, online learning, serious games, student engagement, badges and rewards, and the use of the Internet as a tool for learning.info:eu-repo/semantics/publishedVersio

Adiponectina en suero materno en la enfermedad hipertensiva del embarazo.

Introducción: La adiponectina es una proteína sintetizada en el tejido adiposo blanco, y circula en altas concentraciones (μg/mL) en el suero con efectos antiaterogénico, antidiabético y anti-inflamatorio. Se ha señalado que los niveles de adiponectina disminuyen en pacientes con hipertensión en el embarazo. Objetivo: Evaluar las concentraciones plasmáticas de adiponectina en pacientes con y sin trastornos hipertensivos del embarazo. Método: Es un estudio observacional, longitudinal, prospectivo, no ciego, comparativo, en el que se incluyeron 55 casos pacientes con trastorno hipertensivo del embarazo y 56 controles pacientes normotensas. La adiponectina plasmática se analizó por método de ELISA. Estadística fue con t de Student y valor de p; media, varianza y la prueba U de Mann-Whitney. Resultados: El nivel promedio de adiponectina plasmática de las mujeres con HTA fue significativamente menor que en las pacientes sin HTA (3.12 μg/mL vs. 4.41 μg/ mL) (p ≤0.00042). El análisis de varianzas demostró que la adiponectina fue mayor entre las mujeres con preeclampsia-eclampsia que en las de hipertensión gestacional. Conclusión: Se demostró una disminución significativa de los valores de adiponectina plasmática en pacientes con trastorno hipertensivo del embarazo; los valores fueron aún menores en la hipertensión gestacional que en la preeclampsia-eclampsia (varianza 1.82 vs. 5.25, F = 2.88)

Direct Torque Control based on Virtual Voltage Vector for a Six-phase Induction Machine

[EN] Direct torque control (DTC) strategy is one of the methods used to control multiphase machines. This strategy has been popular in recent decades owing to its speed, robustness and simplicity in the control scheme. However, the appearance of the new secondary x-y currents components typical of multiphase systems can deteriorate the currents quality and increase the losses in the stator copper if they are not regulated properly. That is why the definition and use of the called virtual voltage vectors allow the reduction of these x-y components, thus alleviating the main problem of the direct extension of the DTC to systems with more than three phases. This paper presents the implementation of virtual voltage vectors in a direct torque control for the speed regulation of a six-phase induction machine, validating the goodness of the control strategy proposed by experimental results.[ES] La estrategia de control directo de par (DTC por sus siglas en inglés) es uno de los métodos empleados para el control de máquinas multifásicas. Esta estrategia ha sido popular en las últimas décadas gracias a su rapidez, robustez y simplicidad en el esquema de control. Sin embargo, la aparición de las nuevas componentes secundarias de corrientes x-y propias de los sistemas multifásicos pueden deteriorar la calidad de las corrientes y aumentar las pérdidas en el cobre del estator si no se regulan adecuadamente. Es por ello por lo que la definición y el uso de los denominados vectores virtuales de tensión permiten la reducción de estas componentes x-y, paliando así el principal problema de la extensión directa del DTC a sistemas con más de tres fases. Este artículo presenta la implementación de vectores virtuales de tensión en un control directo de par para la regulación de la velocidad de máquina de inducción de seis fases, validando la bondad de la estrategia de control propuesta mediante resultados experimentales.García Entrambasaguas, P.; González Prieto, I.; Durán Martínez, MJ.; Bermúdez Guzmán, M.; Barrero García, FJ. (2018). Vectores Virtuales de Tensión en Control Directo de Par para una Máquina de Inducción de Seis Fases. Revista Iberoamericana de Automática e Informática industrial. 15(3):277-285. https://doi.org/10.4995/riai.2018.9837OJS277285153Abdel-Khalik, A.S., Masoud, M.I. y Williams, B.W. 2012. Improved flux pattern with third harmonic injection for multiphase induction machines. IEEE Transactions on Power Electronics 27, No. 3, 1563-1578.Abdel-Khalik, A.S., Masoud, M.I. y Williams, B.W. 2012. Vector controlled multiphase induction machine: harmonic injection using optimized constant gains. Electric Power Systems Research 89, 116-128.Alcharea, R., Kianinezhad, R., Nahid-Mobarakeh, B., Betin, F. y Capolino, G.A. 2008. Direct torque control for six-phase symmetrical induction machines. 34th Annual Conference of IEEE Industrial Electronics.Arahal, M.R. y Durán, M.J. 2009. PI tuning of five-phase drives with third harmonic injection. Control Engineering Practice 17, 787-797.Arnanz, R., García, F.J. y Miguel, L.J. 2016. Métodos de control de motores de inducción: síntesis de la situación actual. Revista Iberoamericana de Automática e Informática industrial 13, 381-392.Barrero, F. y Durán, M.J. 2016. Recent advances in the design modeling, and control of multiphase machines - Part I. IEEE Transactions on Industrial Electronics 63, No. 1, 449-458.Benatmane, M. y McCoy, T. 1998. Development of a 19 MW PWM converter for U.S. Navy surface ships. Proc. Int. Conf. ELECSHIP, Istanbul, Turkey, 109-113.Bermúdez, M., González-Prieto, I., Barrero, F., Guzmán, H., Durán, M.J. y Kestelyn, X. 2017. Open-phase fault-tolerant direct torque control technique for five-phase induction motor drives. IEEE Transactions on Industrial Electronics 64, No. 2, 902-911.Bojoi, R., Levi, E., Farina, F., Tenconi, A. y Proumo, F. 2006. Dual three-phase induction motor drive with digital current control in the stationary reference frame. IEEE Proceedings Electric Power Applications 153, No. 1, 29-139.Che, H.S., Levi, E., Jones, M., Hew, W.P. y Rahim, N.A. 2014a. Current control methods for an asymmetrical six-phase induction motor drive. IEEE Transactions on Power Electronics 29, No. 1, 407-417.Che, H.S., Levi, E., Jones, M., Durán, M.J., Hew, W.P. y Rahim, N.A. 2014b. Operation of a six-phase induction machine using series-connected machine-side converters. IEEE Transactions on Industrial Electronics 61, No. 1, 164-176.Che, H.S., Durán, M.J., Levi, E., Jones, M., Hew, W.P. y Rahim, N.A. 2013. Post-fault operation of an asymmetrical six-phase induction machine with single and two isolated neutral points. IEEE Energy Conversion Congress and Exposition, 1131-1138.Cortés, P., Kazmierkowski, M.P., Kennel, R.M., Quevedo, D.E. y Rodríguez, J. 2008. Predictive control in power electronics and drives. IEEE Transactions on Industrial Electronics 55, No. 12, 4312-4324.Durán, M.J., Riveros, J.A., Barrero, F., Guzmán, H. y Prieto, J. 2012. Reduction of common-mode voltage in five-phase induction motor drives using predictive control techniques. IEEE Transactions on Industrial Applications 48, No. 6, 2059-2067.Durán, M.J. y Barrero, F. 2016. Recent Advances in the design modeling, and control of multiphase machines - Part II. IEEE Transactions on Industrial Electronics 63, No. 1, 459-468.Ferreira, C.L. y Bucknall, R.W.G. 2004. Modelling and real-time simulation of an advanced marine full-electrical propulsion system. Proc. IEEE PEMD Conference, Edinburgh, U.K., 2, No. 498, 574-579.Gamesa Technological Corporation S.A., 2016. Gamesa 5.0 MW. Recuperado de: http://www.gamesacorp.com/recursos/doc/ productos-servicios/aerogeneradores/catalogo-g10x-45mw.pdfGao, L., Fletcher, J.E. y Zheng, L. 2011. Low-speed control improvements for a two-level five-phase inverter-fed induction machine using classic direct torque control. IEEE Transactions on Industrial Electronics 58, No. 7, 2744-2754.González, O., Rodas, J., Ayala, M., Gregor, R., Rivera, M., Durán, M. y González-Prieto, I. 2016. Predictive current control with kalman filter observer for a five-phase induction machine operating at fixed switching frequency.González-Prieto, I., Durán, M.J., Barrero, F., Bermúdez, M. y Guzmán, H. 2017. Impact of postfault flux adaptation on six-phase induction motor drives with parallel converters. IEEE Transactions on Power Electronics 32, No. 1, 515-528.González-Prieto, I., Durán, M.J., Che, H.S., Levi, E., Bermúdez, M. y Barrero, F. 2016. Fault-tolerant operation of six-phase energy conversion systems with parallel machine-side converters. IEEE Transactions on Power Electronics 31, No. 4, 3068-3079.González-Prieto, I., Durán, M.J. y Barrero, F. 2016. Fault-tolerant control of six-phase induction motor drives with variable current injection. IEEE Transactions on Power Electronics.Gregor, R., Rodas, J., Gregor, D. y Barrero, F. 2015. Reduced-order observer analysis in MBPC techniques applied to the six-phase induction motor drives. INTECH Open Science.Guzmán, H., Durán, M.J. y Barrero, F. 2012. A comprehensive fault analysis of a five-phase induction motor drive with an open phase. 15th International Power Electronics and Motion Control Conference, LS5b.3-1 - LS5b.3-6.Guzmán, H., Durán, M.J., Barrero, F., Bogado, B. y Toral, S. 2014. Speed control of five-phase induction motors with integrated open-phase fault operation using model-based predictive current control techniques. IEEE Transactions on Industrial Electronics 61, No. 9, 4474-4484.Guzmán, H., Durán, M.J., Barrero, F., Zarri, L., Bogado, B., González-Prieto, I. y Arahal, M.R. 2016. Comparative study of predictive and resonant controllers in fault-tolerant five-phase induction motor drives. IEEE Transactions on Industrial Electronics 63, No. 1, 606-617.Hodge, C., Williamson, S. y Smith, A.C. 2002. Direct drive marine propulsion motors. Proc. Int. Conf. Electrical Machines (ICEM), Bruges, Belgium, CD-ROM, Paper 807.Jones, M., Slobodan, N., Vukosavic, S., Dujic, D. y Levi, E. 2009. A synchronous current control scheme for multiphase induction motor drives. IEEE Transactions on Energy Conversion 24, No. 4, 860-868.Jung, E., Yoo, H., Sul, S., Choi, H. y Choi, Y. 2012. A nine-phase permanent-magnet motor drive system for an ultrahigh-speed elevator. IEEE Transactions on Industrial Applications 48, No. 3, 987-995.Khan, M.R., Iqbal, A. y Ahmad, M. 2008. MRAS-based sensorless control of a vector controlled five-phase induction motor drive. Electric Power Systems Research 78, 1311-1321.Kianinezhad, R., Nahid, B., Betin, F. y Capolino, G.A. 2006. A novel direct torque control (DTC) method for dual three phase induction motors. IEEE International Conference on Industrial Technology.Kianinezhad, R., Alcharea, R., Nahid, B., Betin, F. y Capolino, G.A. 2008. A novel direct torque control (DTC) for six-phase induction motors witch common neutrals. IEEE International Symposium on Power Electronics, Electrical Drives, Automation and Motion.Kouro, S., Cortés, P., Vargas, R., Ammann, U. y Rodríguez, J. 2009. Model predictive control - a simple and powerful method to control power converters. IEEE Transactions on Industrial Electronics 56, No. 6, 1826-1838.Levi, E. 2016. Advances in converter control and innovative exploitation of additional degrees of freedom for multiphase machines. IEEE Transactions on Industrial Electronics 63, No. 1, 433-448.Libo, Z., Fletcher, J.E., Williams, B.W. y Xiangning, H. 2008. Dual-plane vector control of a five-phase induction machine for an improved flux pattern. IEEE Transactions on Industrial Electronics 55, No. 5, 1996-2005.Lu, S. y Corzine, K. 2005. Multilevel multi-phase propulsion drives. Proc. IEEE ESTS, Philadelphia, PA, 363-370.Martín, C., Arahal, M.R., Barrero, F. y Durán, M.J. 2016. Five-phase induction motor rotor current observer for finite control set model predictive control of stator current. IEEE Transactions on Industrial Electronics 63, No. 7, 4527-4538.McCoy, T. y Benatmane, M. 1998. The all-electric warship: An overview of the U.S. Navy's integrated power system development programme. Proc. Int. Conf. ELECSHIP, Istanbul, Turkey, 1-4.Mengoni, M., Zarri, L., Tani, A., Parsa, L., Serra, G. y Casadei, D. 2015. High-torque density control of multiphase induction motor drives operating over a wide speed range. IEEE Transactions on Industrial Electronics 62, No. 2, 814-825.Munim, W.N.W.A., Durán, M.J. Che, H.S, Bermúdez, M. y González-Prieto, I 2016. A unified analysis of the fault tolerance capability in six-phase induction motor drive. IEEE Transactions on Power Electronics.Pandit, J.K., Aware, M.V., Nemade, R.V. y Levi, E. 2017. Direct torque control scheme for a six-phase induction motor with reduced torque ripple. IEEE Transactions on Industrial Electronics 32, No. 9, 7118-7129.Ren, Y. y Zhu, Z.Q. 2015a. Enhancement of steady-state performance in direct-torque-controlled dual three-phase permanent-magnet synchronous machine drives with modified switching table. IEEE Transactions on Industrial Electronics 62, No. 6, 3338-3350.Ren, Y. y Zhu, Z.Q. 2015b. Reduction of both harmonic current and torque ripple for dual three-phase permanent-magnet synchronous machine using modified switching-table-based direct torque control. IEEE Transactions on Industrial Electronics 62, No. 11, 6671-6683.Ríos-García, N., Durán, M.J., González-Prieto, I., Martín, C. y Barrero, F. 2017. An open-phase fault detection method for six-phase induction motor drives. International Conference on Renewable Energies and Power Quality.Riveros, A., Yepes, A.G., Barrero, F., Doval-Gandoy, J., Bogado, B., López, O., Jones, M. y Levi, E. parameter identification of multiphase induction machines with distributed windings-Part 2: time-domain techniques. IEEE Transactions on Energy Conversion 27, No. 4, 1067-1077, 2012.Simoes, M.G. y Vieira, P. 2002. A high-torque low-speed multiphase brushless machine - A perspective application for electric vehicles. IEEE Transactions on Industrial Electronics 49, No. 5, 1154-1164.Singh, G.K., Nam, K. y Lim, S.K. 2005. A simple indirect field-oriented control scheme for multiphase induction machine. IEEE Transactions on Industrial Electronics 52, No. 4, 1177-1184.Smith, S. 2002. Developments in power electronics, machines and drives. IEEE Power Engineering Journal 16, No. 1, 13-17.Sudhoff, S.D., Alt, J.T., Hegner, N.J. y Robey, H.N. Jr. 1997. Control of a 15-phase induction motor drive system. Proc. Naval Symp. Electr. Mach., Newport, RI, 69-75.Taheri, A. 2016. Harmonic reduction of direct torque control of six-phase induction motor. ISA Transactions 63, 299-314.Tani, A., Mengoni, M., Zarri, L., Serra, G. y Casadei, D. 2012. Control of multiphase induction motors with an odd number of phases under open-circuit phase faults. IEEE Transactions on Power Electronics 27, No. 2, 565-577.Terrien, F., Siala, S. y Noy, P. 2004. Multiphase induction motor sensorless control for electric ship propulsion. Proc. IEEE PEMD Conference, Edinburgh, U.K., 2, No. 498, 556-561.Vukosavic, S., Jones, M., Levi, E. y Varga, J. 2005. Rotor flux oriented control of a symmetrical six-phase induction machine. Electric Power Systes Research 75, No. 2/3, 142-152.Yaramasu, V., Dekka, A., Durán, M.J., Kouro, S. y Wu, B. 2017. PMSG-based wind energy conversion systems: survey on power converters and control. IET Electric Power Aplications, 13 pp.Yepes, A.G., Malvar, J., Vidal, A., López, O. y Doval-Gandoy, J. 2015. Current harmonic compensation based on multiresonant control in synchronous frame for symmetrical n-phase machines. IEEE Transactions on Industrial Electronics 62, No. 5, 2708-2720.Zhao, Y. y Lipo, T.A. 1995. Space vector PWM control of dual three-phase induction machine using vector space decomposition. IEEE Transactions on Industry Applications 31, No. 5, 1100-1109.Zheng, L., Fletcher, J.E., Williams, B.W. y He, X. 2011. A novel direct torque control scheme for a sensorless five-phase induction motor drive. IEEE Transactions on Industrial Electronics 58, No. 2, 503-513

Water diversion and pollution interactively shape freshwater food webs through bottom-up mechanisms

[EN] Water diversion and pollution are two pervasive stressors in river ecosystems that often co-occur. Individual effects of both stressors on basal resources available to stream communities have been described, with diversion reducing detritus standing stocks and pollution increasing biomass of primary producers. However, interactive effects of both stressors on the structure and trophic basis of food webs remain unknown. We hypothesized that the interaction between both stressors increases the contribution of the green pathway in stream food webs. Given the key role of the high-quality, but less abundant, primary producers, we also hypothesized an increase in food web complexity with larger trophic diversity in the presence of water diversion and pollution. To test these hypotheses, we selected four rivers in a range of pollution subject to similar water diversion schemes, and we compared food webs upstream and downstream of the diversion. We characterized food webs by means of stable isotope analysis. Both stressors directly changed the availability of basal resources, with water diversion affecting the brown food web by decreasing detritus stocks, and pollution enhancing the green food web by promoting biofilm production. The propagation of the effects at the base of the food web to higher trophic levels differed between stressors. Water diversion had little effect on the structure of food webs, but pollution increased food chain length and trophic diversity, and reduced trophic redundancy. The effects at higher trophic levels were exacerbated when combining both stressors, as the relative contribution of biofilm to the stock of basal resources increased even further. Overall, we conclude that moderate pollution increases food web complexity and that the interaction with water abstraction seems to amplify this effect. Our study shows the importance of assessing the interaction between stressors to create predictive tools for a proper management of ecosystems.Ministerio de Economia, Industria y Competitividad, Gobierno de Espana, Grant/Award Number: GL2016-77487-R; European Social Fund; Diputacion Foral de Bizkaia; Serra Hunter Fellow; Labex, Grant/Award Number: ANR-10-LABX-41; H2020 European Research Council; Eusko Jaurlaritza; Consejo Nacional de Investigaciones Cientificas y Tecnicas; FRAGCLIM Consolidator, Grant/Award Number: 72617

Diagnóstico y evaluación de los factores de riesgo psicosociales relacionados con clima organizacional de la estación de policía de sonsón antioquia para el año 2021

lista de gráficas, cuadros y entrevistaClima organizacional son el mecanismo que adopta más importancia en la competitividad institucional, este componente abarca las características que equilibran a una organización, estas incluyen el ambiente laboral la percepción que tienen los empleados frente a la institución y cómo influye ésta en ellos. El de este estudio es establecer la eficiencia y eficacia de la mediación psicológica en el progreso del ambiente o clima de la organización dentro de la estación de policía de Sonsón Antioquia; la población objeto de estudio estuvo conformada por 22 uniformados hombres y mujeres que trabajan en la estación. El proceso de investigación se desarrolló mediante una entrevista semiestructurada aplicada a los integrantes de la estación de policía de Sonsón Antioquia, logrando identificar aquellos factores que generan estrés en el personal uniformado y que provocan afectación al clima organizacional, logrando identificar las mejores acciones en el marco de las prácticas y gestión de talento humano.The organizational climate is the most important mechanism in institutional competitiveness, this component covers the characteristics that balance an organization, these include the work environment, the perception that employees have of the institution and how it influences them. The objective of this study is to establish the efficiency and effectiveness of psychological mediation in the progress of the organizational climate in the Sonsón Antioquia police station; the sample consisted of 22 uniformed men and women who work at the station. The investigation process was developed through a semi-structured interview applied to the members of the Sonsón Antioquia police station, managing to identify those factors that generate stress in uniformed personnel and that affect the organizational climate, managing to identify the best human talent management practices

Hepatoprotective effect of commercial herbal extracts on carbon tetrachloride-induced liver damage in Wistar rats

Background: The antioxidant and anti-inflammatory effects of arbutin protect against a number of diseases. Objectives: The present study evaluated the protective effect of arbutin against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. Methods: Sixty-three Wistar rats were divided into nine groups. Groups I and II were the normal control groups. Group III, the hepatotoxic group, was given CCl4. Groups IV, VI, and VIII received different dosages of arbutin along with CCl4. Groups V, VII, and IX were administered different dosages of arbutin. The albumin content, total protein, and bilirubin were assayed to determine their serum and antioxidant levels; lipid peroxidation was assessed in the serum and liver tissue. Histological studies were carried out to confirm the biochemical results. Results: Treatment with CCl4 for 28 d decreased the levels of total protein and albumin and increased the level of bilirubin and lipid peroxidation. Arbutin treatment raised the level of albumin and lowered the lipid peroxidation to normal levels. Necrosis and fibrosis were observed in the liver tissue of CCl4-injected rats, and the administration of arbutin had a protective effect on the liver tissue. Conclusions: The results of this study showed that arbutin may protect the liver against CCl4-induced oxidative damage in rats. This hepatoprotective effect might be correlated with the antioxidant and free radical scavenger effects of arbutin

Does native Trypanosoma cruzi calreticulin mediate growth inhibition of a mammary tumor during infection?

Indexación: Web of Science.Background: For several decades now an antagonism between Trypanosoma cruzi infection and tumor development has been detected. The molecular basis of this phenomenon remained basically unknown until our proposal that T. cruzi Calreticulin (TcCRT), an endoplasmic reticulum-resident chaperone, translocated-externalized by the parasite, may mediate at least an important part of this effect. Thus, recombinant TcCRT (rTcCRT) has important in vivo antiangiogenic and antitumor activities. However, the relevant question whether the in vivo antitumor effect of T. cruzi infection is indeed mediated by the native chaperone (nTcCRT), remains open. Herein, by using specific modified anti-rTcCRT antibodies (Abs), we have neutralized the antitumor activity of T. cruzi infection and extracts thereof, thus identifying nTcCRT as a valid mediator of this effect. Methods: Polyclonal anti-rTcCRT F(ab')(2) Ab fragments were used to reverse the capacity of rTcCRT to inhibit EAhy926 endothelial cell (EC) proliferation, as detected by BrdU uptake. Using these F(ab')(2) fragments, we also challenged the capacity of nTcCRT, during T. cruzi infection, to inhibit the growth of an aggressive mammary adenocarcinoma cell line (TA3-MTXR) in mice. Moreover, we determined the capacity of anti-rTcCRT Abs to reverse the antitumor effect of an epimastigote extract (EE). Finally, the effects of these treatments on tumor histology were evaluated. Results: The rTcCRT capacity to inhibit ECs proliferation was reversed by anti-rTcCRT F(ab')(2) Ab fragments, thus defining them as valid probes to interfere in vivo with this important TcCRT function. Consequently, during infection, these Ab fragments also reversed the in vivo experimental mammary tumor growth. Moreover, anti-rTcCRT Abs also neutralized the antitumor effect of an EE, again identifying the chaperone protein as an important mediator of this anti mammary tumor effect. Finally, as determined by conventional histological parameters, in infected animals and in those treated with EE, less invasive tumors were observed while, as expected, treatment with F(ab')(2) Ab fragments increased malignancy. Conclusion: We have identified translocated/externalized nTcCRT as responsible for at least an important part of the anti mammary tumor effect of the chaperone observed during experimental infections with T. cruzi.http://bmccancer.biomedcentral.com/articles/10.1186/s12885-016-2764-

Spironolactone Effect in Hepatic Ischemia/Reperfusion Injury in Wistar Rats

Introduction. Ischemia/reperfusion (IR) injury, often associated with liver surgery, is an unresolved problem in the clinical practice. Spironolactone is an antagonist of aldosterone that has shown benefits over IR injury in several tissues, but its effects in hepatic IR are unknown. Objective. To evaluate the effect of spironolactone on IR-induced damage in liver. Materials and Methods. Total hepatic ischemia was induced in rats for 20 min followed by 60 min of reperfusion. Spironolactone was administered and hepatic injury, cytokine production, and oxidative stress were assessed. Results. After IR, increased transaminases levels and widespread acute inflammatory infiltrate, disorganization of hepatic hemorrhage trabeculae, and presence of apoptotic bodies were observed. Administration of SPI reduced biochemical and histological parameters of liver injury. SPI treatment increased IL-6 levels when compared with IR group but did not modify either IL-1β or TNF-α with respect to IR group. Regarding oxidative stress, increased levels of catalase activity were recorded in IR + SPI group in comparison with group without treatment, whereas MDA levels were similar in IR + SPI and IR groups. Conclusions. Spironolactone reduced the liver damage induced by IR, and this was associated with an increase in IL-6 production and catalase activity