197 research outputs found

    In-vitro application of pentoxifylline preserved ultrastructure of spermatozoa after vitrification in asthenozoospermic patients

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    Abstract PURPOSE: To evaluate the effect of in vitro application of pentoxifylline (PX) on sperm parameters and ultrastructure after vitrification in asthenozoospermic patients. MATERIALS AND METHODS: A total of 30 asthenozoospermic semen samples (aged 25-45 years) were divided into four groups before vitrification, after vitrification, control (without PX) and experimental (with PX). In experimental group, each sample was exposed for 30 min to 3.6mmol/l PX and the control group without any treatment apposing in 370C for 30 min. After incubation, the samples were washed and analyzed again. Vitrification was done according to straw method. Eosin-nigrosin and Papanicolaou staining were applied for assessment of sperm viability and morphology, respectively. The samples without PX and post treatment with PX were assessed by transmission electron microscopy (TEM). RESULTS: A significant decrease in sperm motility (P ≤ .001), morphology (11.47 ± 2.9 versus 6.73 ± 2.01) and viability (73.37 ± 6.26 versus 54.67 ± 6.73) was observed post vitrification, but sperm motility (19.85 ± 4.75 versus 32.07 ± 5.58, P ≤ .001) was increased significantly following application of PX. This drug had no significant (P >.05) detrimental neither negative effect on ultrastructure acrosome, plasma membrane and coiled tail statues of spermatozoa. CONCLUSION: Vitrification had detrimental effects on sperm parameters, but PX reversed detrimental effects on sperm motility. However, PX had no alteration on ultrastructure morphology of human spermatozoa after vitrification

    Effect of syngas composition on the combustion and emissions characteristics of a syngas/diesel RCCI engine

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    Reactivity controlled compression ignition (RCCI) strategy uses two different fuels with different reactivities which provides more control over the combustion process and has the potential to dramatically lower combustion temperature and NOX and PM emissions. The objective of the present study is to numerically investigate the impact of syngas composition on the combustion and emissions characteristics of an RCCI engine operating with syngas/diesel at constant energy per cycle. For this purpose, different syngas compositions produced through gasification process have been chosen for comparison with the simulated syngas (mixture of hydrogen and carbon monoxide). The results obtained indicate that using syngas results in more soot, CO and UHC emissions compared with simulated syngas. Even though more NOX reduction can be achieved while operating with syngas, the engine could suffer from poor combustion and misfire at low loads due to the presence of nitrogen in the mixture. In terms of exergy, both syngas mixtures lead to more exergy destruction by the increase of syngas substitution. Nevertheless, the magnitude of exergy destruction for simulated syngas is less than the normal syngas

    Retraction Note: Ambient particulate matter concentration levels of Ahvaz, Iran, in 2017 (Environmental Geochemistry and Health, (2019), 41, 2, (841-849), 10.1007/s10653-018-0182-0)

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    The Editor-in-Chief has retracted this article because it contains material that substantially overlaps with another published article [1]. Sina Dobaradaran agrees to this retraction. Gholamreza Goudarzi, Sahar Geravandi, and Mohammad Javad Mohammadi do not agree to this retraction. Nadali Alavi, Ahmad Reza Yari, Farzaneh Aslanpour Alamdari, Majid Farhadi, Hamed Biglari, Maryam Dastoorpour, and Bayram Hashemzadeh have not responded to any correspondence from the publisher about this retraction

    Predicting inpatient length of stay in Iranian Hospital: Conceptualization and validation

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    Objective: The length of stay is an important indicator of hospital performance and efficiency. Regarding the importance of the length of stay, this study aimed to design a structural model of the inpatients' length of stay in the educational and therapeutic health care facilities of Iran in order to identify the influencing dimensions. Methods: The present study was an analytical and applied study. The face validity of the data gathering tool was investigated by the expert judgment and the construct validity was examined by using the exploratory factor analysis. In order to verify the reliability of the tool, the internal consistency was also trialed by using the Cronbach's alpha. For ranking the influencing dimensions and factors and also in order to examine the causal relationships between the variables in a coherent manner and presenting the final model, the structural equation modeling technique was used in AMOS software at a significant level of 0.05. Results: The mentioned structural model consists of 4 dimensions and 29 factors influencing the length of stay of hospitalized patients. The independent variables are based on priority and importance as follows: patients' conditions, the underlying factors, the clinical staff performance, and hospitals' service delivery, which were examined by second-order factor analysis in order to study the relationship between them and the inpatients' length of stay. Conclusion: Considering the importance of each one of the proposed dimensions from the point of view of service providers in some therapeutic centers of the country by paying attention to the role of each one of them in preventing prolonged hospitalization can be essential in the effectiveness of the treatment and cost reduction. © 2020 Asian Pacific Organization for Cancer Prevention

    The effect of aminoguanidine on sperm motility and mitochondrial membrane potential in varicocelized rats

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    Objective(s): Increased levels of nitric oxide (NO) in the testicular veins of people suffering from varicocele have already been reported. However, the role of NO-synthase (NOS) isozymes and their inhibitors have not been extensively studied. We aimed to evaluate the inhibitory effects of aminoguanidine (AG), on sperm motility, vitality, and mitochondrial membrane potential (MMP) in varicocelized rats. Materials and Methods: Twenty fore male Wister rats were divided into control, sham, varicocele, and treatment groups. Varicocele and treatment groups underwent partial ligation of left renal vein. Rats in the sham group underwent the same procedures as the varicocele group with the exception of vein ligation. 10 weeks after varicocele induction, sperm parameters were evaluated in all groups. The treatment group received 50 mg/kg AG injection daily for 10 weeks after which they were sacrificed prior to assessment of the parameters. Sperm viability and MMP were assessed by flow cytometry using propidium iodide (PI) and rhodamine 123 (Rh123), respectively. Results: The results of this study show a decrease in sperm viability, motility and MMP in the varicocele group compared with the other groups. After AG injection, we observed that all the parameters were significantly enhanced in the treatment group compared with the other groups. Rh123 staining revealed a positive relation between MMP and sperm motility, whereas PI staining showed a positive relation between sperm motility and viability. Conclusion: The findings of our study show that AG improves sperm motility and MMP, and thus, might be useful in the management of varicocele-related infertility. © 2016, Mashhad University of Medical Sciences. All rights reserved

    Reversible Pulmonary Hypertension and Isolated Right-sided Heart Failure Associated with Hyperthyroidism

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    Hyperthyroidism may present with signs and symptoms related to dysfunction of a variety of organs. Cardiovascular pathology in hyperthyroidism is common. A few case reports describe isolated right heart failure, tricuspid regurgitation, and pulmonary hypertension as the prominent cardiovascular manifestations of hyperthyroidism. Although most textbooks do not mention hyperthyroidism as a cause of pulmonary hypertension and isolated right heart failure, the literature suggests that some hyperthyroid patients may develop reversible pulmonary hypertension and isolated right heart failure. We report a case of hyperthyroidism presenting with signs and symptoms of isolated right heart failure, tricuspid regurgitation, and pulmonary hypertension, which resolved with treatment of hyperthyroidism

    Entrepreneurial intentions and entrepreneurship education to University students in Portugal

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    [EN] This article analyzes entrepreneurial intentions and motivations that encourage university students of Tourism to create their own company. Methodology is based on an empirical study, using a questionnaire adapted from a model of Veciana and Urbano (Actitudes de los estudiantes universitarios hacia la creación de empresas: un estudio empírico comparativo entre Catalunya y Puerto Rico. El emprendedor innovador y la creación de empresas de I + D + I, University of Valencia, pp 35 58, 2004), including the desirability and viability concepts. One hundred and sixty students answered the questionnaire from a total study population of 243 official Tourism degree students of the Superior Institute of Accounting and Management of Porto. This research finds out that the university students have a very positive perception about the desire to create their own company; a 90 % of students express their desire to do it, and 83.5 % express their intention. Moreover, a 57.5 % think that within actual crisis it is more difficult to do than before it. This research lets us get an in-depth study of a student of Tourism degree, finding out his entrepreneurial attitudes. It can be the first step to wake up and encourage students interest for starting up their own business.Del Rio-Rama, MDLC.; Peris-Ortiz, M.; Álvarez García, J.; Rueda Armengot, C. (2016). Entrepreneurial intentions and entrepreneurship education to University students in Portugal. Technology, Innovation and Education. 2(7):1-11. doi:10.1186/s40660-016-0013-5S11127Ajzen I (1991) The theory of plannes behavior. Organ Behav Hum Decis Process 50:179–211Aponte M (2002) Factores condicionantes de la creación de empresas en Puerto Rico: un enfoque institucional. Doctoral dissertation, Autonomous University of BarcelonaAponte M, Urbano D, Veciana JM (2006) Actitudes hacia la creación de empresas: un estudio comparativo entre Catalunya y Puerto Rico. Centro de Investigaciones Comerciales e Iniciativas Académicas de la Facultad de Administración de Empresas. Forum Empresarial 11(2):52–75Bae TJ, Qian S, Miao C, Fiet JO (2014) The relationship between entrepreneurship education and entrepreneurial intentions: a meta-analytic review. Entrep Theory Pract 38(2):217–254Brice J (2004) The role of personality dimensions on the formation of entrepreneurial intentions. USASBE Small Business Advancement National Center. University of Central Arkansas, USACabana-Villca R, Cortes-Castillo I, Plaza-Pasten D, Castillo-Vergara M, Alvarez-Marin A (2013) Análisis de las capacidades emprendedoras potenciales y efectivas en alumnos de centros de educación superior. J Technol Manag Innov 8(1):65–75Davidsson P (1989) Continued entrepreneurship and small firm business. Stockholm School of Economics, StockholmDavidsson P (1995) Culture, structure and regional levels of entrepreneurship. Entrep Reg Dev 7(1):41–62De Jorge-Moreno J, Castillo LL, Triguero MS (2012) The effect of business and economics education programs on students’ entrepreneurial intention. Eur J Train Dev 36(4):409–425Díaz JC, Hernández RM, Barata ML (2007) Estudiantes universitarios y creación de empresas. Un análisis comparativo entre España y Portugal. In Ayala, J.C. (coord.) Conocimiento, innovación y emprendedores: camino al futuro. Grupo FEDRA, MadridDo Paço AMF, Ferreira JM, Raposo M, Rodrigues RG, Dinis A (2011) Behaviours and entrepreneurial intention: empirical findings about secondary students. J Int Entrep 9(1):20–38Dohse D, Walter SG (2010) The role of entrepreneurship education and regional context in forming entrepreneurial intentions (No. 2010, 18). Document de treball de l’IEBEuropean Commission (2006). Entrepreneurship education in Europe: Fostering entrepreneurial mindsets through education and learning, Final Proceedings of the Conference on Entrepreneurship Education in OsloEurostat (2014) Informes sobre el empleo en la Unión Europea. Available in: http://europa.eu/publications/statistics/index_es.htmFuentes F, Saco F, Rodríguez P (2013) Estudio sobre el perfil emprendedor en el alumnado universitario de Córdoba. UCO Consejo Social de la Universidad de Córdoba, III Edición, Córdoba, pp 1–180Fuentes García FJ (2007) Análisis del Perfil Emprendedor del alumnado universitario y preuniversitario de Córdoba. Consejo Social Universidad de Córdoba, pp 1–105Genesca Garrigosa E, Veciana Verges JM (1984) Actitudes hacia la creación de empresas. Información Comercial Española 611:147–155Gerba DT (2012) Impact of entrepreneurship education on entrepreneurial intentions of business and engineering students in Ethiopia. Afr J Econ Manag Stud 3(2):258–277Gorman G, Hanlon D, King W (1997) Some research perspectives on entrepreneurship education and education for small business management: a ten-year literature review. Int Small Bus J 15(3):56–77Guerrero M, Rialp J, Urbano D (2008) The impact of desirability and feasibility on entrepreneurial intentions: a structural equation model. Int Entrep Manag J 4(1):35–50Haynie JM, Shepherd DA, McMullen JS (2009) An opportunity for me? The role of resources in opportunity evaluation decisions. J Manage Stud 46(3):337–361Hernangomez J, Martín N, Rodriguez AI, Saboia F (2005) El emprendedor nace o se hace? Un análisis de los determinantes del espíritu emprendedor. XVI Spanish-Portuguese Meeting of Scientic Management. Sevilla:33–44Hmieleski KM, Corbett AC (2006) Proclivity for improvisation as a predictor of entrepreneurial intentions. J Small Bus Manage 44(1):45–63Honjo Y (2004) Growth of new start-up firms: evidence from the Japanese manufacturing industry. Appl Econ Lett 11(1):21–32Hyde GC (1989) The relationship between policy and research. In Rosa, P.; Birley, S. Cannon, T. and O´Neill, K. The Role and Contribution of Small Business Research, Chap. 3:55–77, Institute ReportKolvereid L (1996) Prediction of employment status choice intentions. Entrep Theory Pract 21(1):47–57Kourilsky ML, Walstad WB (1998) Entrepreneurship and female youth: knowledge, attitude, gender differences, and educational practices. J Bus Ventur 13(1):77–88Krueger N, Brazeal D (1994) Entrepreneurial Potencial and Potencial Entrepreneurs. Entrep Theory Pract 18(3):91–104Krueger NF, Carsrud AL (1993) Entrepreneurial intentions: applying the theory of planned behaviour. Entrep Reg Dev 5(4):315–330Lanero A, Vázquez JL, Gutiérrez P, García MP (2011) The impact of entrepreneurship education in European universities: an intention-based approach analyzed in the Spanish area. Int Rev Public Nonprofit Marketin 8(2):111–130Miller BK, Bell JD, Palmer M, González A (2009) Predictors of entrepreneurial intentions: a quasi-experiment comparing students enrolled in introductory management and entrepreneurship classes. J Bus Entrep 21(2):39–62Neck HM, Zacharakis AL, Bygrave WD, Reynolds PD (2003) Global entrepreneurship monitor: 2002 executive report. Babson College, Babson, MANorth DC (1990) Institutions, Institutional Change and Economic Performance. Cambridge University Press, Cambridge (UK)North D (1993) Instituciones, cambio institucional y desempeño económico. Fondo de Cultura Económica, MéxicoNorth DC (2005) Understanding the Process of Economic Change. Academic Foundation. University Press, PrincentonGEM Portugal (2012) Estudo sobre o Empreendedorismo. Global Entrepreneruship Monitor (GEM). Instituto Universitário de Lisboa (ISCTEIUL) http://web.spi.pt/GEMportugal2012/files/GEM_PORTUGAL_2012.pdfRaposo M, do Paço A, Ferreira J (2008a) Entrepreneur’s profile: a taxonomy of attribu tes and motivations of university students. J Small Bus Enterp Dev 15(2):405–420Raposo MLB, Ferreira JJM, do Paço AMF, Rodrigues RJG (2008b) Propensity to firm creation: empirical research using structural equations. Int Entrep Manag J 4(4):485–504Robinson PB, Stimpson DV, Huefner JC, Hunt HK (1991) An attitude approach to the prediction of entrepreneurship. Entrep Theory Pract 15(4):13–31Samad Aghayi J (2008) Entrepreneurship organization. Public Administration Training Center Publications, TehranScherer RF, Adams JS, Carley S, Wiebe FA (1989) Role model performance effects on development of entrepreneurial career preference. Entrep Theory and Pract, spring:53–71Scherer RF, Brodzinski JD, Wiebe F (1991) Examining the relationship between personality and entrepreneurial career preference. Entrep Reg Dev 3(2):195–206Shane S (2003) A General Theory of Enttrepreneurship- The Individual Oportunity Nexus. Edward Elgar EditoresShapero A (1982) Social dimensions of entrepreneurship. In: Kent CA et al (eds) The encyclopedia of entrepreneurship. Prentice-Hall, Englewood Cliffs, pp 72–89Shapero A, Sokol L (1982) The social dimensions of entrepreneurship.Encyclopedia of Entrepreneurship:72–90Storey DJ (1994) Employment. In Storey, D.J. Understanding the small business sector. Capítulo 6, pp. 160–203. London: RoutledgeToledano N, Urbano D (2008) Promoting entrepreneurial mindsets at universities: a case study in the South of Spain. Eur J Int Manag 2(4):382–399Trequattrini R, Lombardi R, Lardo A, Cuozzo B (2015). The Impact of Entrepreneurial Universities on Regional Growth: a Local Intellectual Capital Perspective. Journal of the Knowledge Economy, 1–13Urbano D (2006) La creación de empresas en Catalunya. Organismos de apoyo y actitudes hacia la actividad emprendedora, Ed. Generalitat de Catalunya-CIDEM, BarcelonaUrbano D, Toledano N (2008) The systems of university education and their influence on the students’ attitudes in the business world: a multiple case study. Oikos 25:87–103Veciana JM (1989) Características del empresario en España. Papeles de Economía Española 39:19–36Veciana JM, Urbano D (2004) Actitudes de los estudiantes universitarios hacia la creación de empresas: un estudio empírico comparativo entre Catalunya y Puerto Rico. El emprendedor innovador y la creación de empresas de I + D + I, University of Valencia, pp 35–58Veciana JM, Aponte M, Urbano D (2005) University student’s attitudes towards entrepreneurship: a two countries comparison. Int Entrep Manag J 1:165–182Wang CK, Wong PK (2004) Entrepreneurial interest of university students in Singapore. Technovation 24(2):163–172White SB, Reynolds PD (1996) Government programs and high growth new firms. Frontiers of Entrepreneurship Research. Center for Entrepreneurial Studies Babson College. Wellesley, MA.: 621–635Yari A, Toulabi Z, Pourashraf Y (2013) Designing propensity to entrepreneurship paradigm in Ilam universities (structural equation model approach). J Novel Appl Sci 2:872–88

    p53 Transactivation and the Impact of Mutations, Cofactors and Small Molecules Using a Simplified Yeast-Based Screening System

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    The p53 tumor suppressor, which is altered in most cancers, is a sequence-specific transcription factor that is able to modulate the expression of many target genes and influence a variety of cellular pathways. Inactivation of the p53 pathway in cancer frequently occurs through the expression of mutant p53 protein. In tumors that retain wild type p53, the pathway can be altered by upstream modulators, particularly the p53 negative regulators MDM2 and MDM4. promoter, ii) single copy, chromosomally located p53-responsive and control luminescence reporters, iii) enhanced chemical uptake using modified ABC-transporters, iv) small-volume formats for treatment and dual-luciferase assays, and v) opportunities to co-express p53 with other cofactor proteins. This robust system can distinguish different levels of expression of WT and mutant p53 as well as interactions with MDM2 or 53BP1.We found that the small molecules Nutlin and RITA could both relieve the MDM2-dependent inhibition of WT p53 transactivation function, while only RITA could impact p53/53BP1 functional interactions. PRIMA-1 was ineffective in modifying the transactivation capacity of WT p53 and missense p53 mutations. This dual-luciferase assay can, therefore, provide a high-throughput assessment tool for investigating a matrix of factors that can influence the p53 network, including the effectiveness of newly developed small molecules, on WT and tumor-associated p53 mutants as well as interacting proteins

    A systematic review evaluating the psychometric properties of measures of social inclusion

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    Introduction: Improving social inclusion opportunities for population health has been identified as a priority area for international policy. There is a need to comprehensively examine and evaluate the quality of psychometric properties of measures of social inclusion that are used to guide social policy and outcomes. Objective: To conduct a systematic review of the literature on all current measures of social inclusion for any population group, to evaluate the quality of the psychometric properties of identified measures, and to evaluate if they capture the construct of social inclusion. Methods: A systematic search was performed using five electronic databases: CINAHL, PsycINFO, Embase, ERIC and Pubmed and grey literature were sourced to identify measures of social inclusion. The psychometric properties of the social inclusion measures were evaluated against the COSMIN taxonomy of measurement properties using pre-set psychometric criteria. Results: Of the 109 measures identified, twenty-five measures, involving twenty-five studies and one manual met the inclusion criteria. The overall quality of the reviewed measures was variable, with the Social and Community Opportunities Profile-Short, Social Connectedness Scale and the Social Inclusion Scale demonstrating the strongest evidence for sound psychometric quality. The most common domain included in the measures was connectedness (21), followed by participation (19); the domain of citizenship was covered by the least number of measures (10). No single instrument measured all aspects within the three domains of social inclusion. Of the measures with sound psychometric evidence, the Social and Community Opportunities Profile-Short captured the construct of social inclusion best. Conclusions: The overall quality of the psychometric properties demonstrate that the current suite of available instruments for the measurement of social inclusion are promising but need further refinement. There is a need for a universal working definition of social inclusion as an overarching construct for ongoing research in the area of the psychometric properties of social inclusion instruments
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