Nitric oxide (NO) a free radical having both cytoprotective as well as tumor promoting agent is formed from l-arginine by converting it to l-citrulline via nitric oxide synthase enzymes. The reaction product of nitric oxide with superoxide generates potent oxidizing
agent, peroxynitrite which is the main mediator of tissue and cellular injury. Peroxynitrite is reactive towards many biomolecules
which includes amino acids, nucleic acid bases; metal containing compounds, etc. NO metabolites may play a key role in mediating
many of the genotoxic/carcinogenic effects as DNA damage, protein or lipid modification, etc. The basic reactions of nitric
oxide can be divided as direct effect of the radical where it alone plays a role in either damaging or protecting the cell
milieu and an indirect effect in which the byproducts of nitric oxide formed by convergence of two independent radical generating
pathways play the role in biological reactions which mainly involve oxidative and nitrosative stress. Nitric oxide is also
capable of directly interacting with mitochondria through inhibition of respiration or by permeability transition. Reaction
of nitric oxide with metal ions include its direct interaction with the metals or with oxo complexes thereby reducing them
to lower valent state. Excessive production of nitric oxide can be studied by inhibiting the synthetic pathway of nitric oxide
using both selective or specific nitric oxide synthase inhibitor or non-selective nitric oxide synthase inhibitor with respect
to isoforms of nitric oxide. 相似文献
This paper presents the development of an Argument-Learning System （ALES）. The idea is based on the AIF （argumentation interchange format） ontology using ＂Walton theory＂. ALES uses different mining techniques to manage a highly structured arguments repository. This repository was designed, developed and implemented by the authors. The aim is to extend the previous framework proposed by developing an intelligent tutoring environment for argument learning that aims to： （1） guide the students during argument learning; （2） aid in improving the students＇ argument skills; and （3） offer an argument classifier agent that retrieves the most relevant results to the subject of search. This paper focuses on the environment development specifying the status of each of the constituent modules. 相似文献
AbstractMedia competencies are a set of skills that every individual should possess in order to be able to consume and produce media and digital and information products in a critical and analytical way. This exploratory and comparative work analyses the level of media competence among 1,676 university students and 524 professors in Brazil, Spain, Portugal and Venezuela. One of the main results shows that the level of knowledge of technology and interaction — which is linked to digital competencies — does not depend solely on age, thus contradicting theories of digital natives and migrants. Our study also found that the general level of media competence is no better than medium to low when considering language, technology, interaction, production and dissemination, ideology and values, and aesthetics. These results point to the need to develop transversal actions for instructing both university professors and students in media competencies to face an ecosystem dominated by fake news and disinformation, as well as public policies directed at improving these skills among citizens at large. 相似文献
This study evaluated effect of mental rotation (MR) training on learning outcomes and explored effectiveness of teaching via three-dimensional (3D) software among medical students with diverse spatial intelligence. Data from n = 67 student volunteers were included. A preliminary test was conducted to obtain baseline level of MR competency and was utilized to assign participants to two experimental conditions, i.e., trained group (n = 25) and untrained group (n = 42). Data on the effectiveness of training were collected to measure participants’ speed and accuracy in performing various MR activities. Six weeks later, a large class format (LCF) session was conducted for all students using 3D software. The usefulness of technology-assisted learning at the LCF was evaluated via a pre- and post-test. Students’ feedback regarding MR training and use of 3D software was acquired through questionnaires. MR scores of the trainees improved from 25.9±4.6 points to 28.1±4.4 (P = 0.011) while time taken to complete the tasks reduced from 20.9±3.9 to 12.2±4.4 minutes. Males scored higher than females in all components (P = 0.016). Further, higher pre- and post-test scores were observed in trained (9.0±1.9 and 12.3±1.6) versus untrained group (7.8±1.8; 10.8±1.8). Although mixed-design analysis of variance suggested significant difference in their test scores (P < 0.001), both groups reported similar trend in improvement by means of 3D software (P = 0.54). Ninety-seven percent of students reported technology-assisted learning as an effective means of instruction and found use of 3D software superior to plastic models. Software based on 3D technologies could be adopted as an effective teaching pedagogy to support learning across students with diverse levels of mental rotation abilities. 相似文献
La propuesta curricular de la Generalitat de Catalunya y el modelo curricular de la LOGSE son dos realizaciones sucesivas, y por ese orden, del mismo planteamiento. Incluimos aquí esta propuesta curricular como la primera de otras posibles que versen sobre el tratamiento que reciben los códigos de representación en la reforma que viene y como un elemento mas del debate científico-profesional al que desde ahora invitamos a nuestros lectores. 相似文献
The research reported here was part of a large study of the impact of age, disability, race and sex on the teaching profession in England. The basic question asked in this research was how do these factors interact with career aspirations and achievements of classteachers, promoted teachers and headteachers? There were three different data sources: a large postal survey drawn from diverse geographic regions across England with over 2000 respondents; face‐to‐face individual interviews with over 100 teachers in 18 case study schools from across all of the main regions of England; discussions with special interest groups of teachers. Not surprisingly, the answer to the above question was complex. Nonetheless, the paper's conclusion highlights some of the noteworthy themes across this broad sample of teachers from primary, secondary and special schools.
Les travaux de recherche décris dans cet article ont fait partie d'une large étude sur l'impact de l'age, des handicaps, de l'origine ethnique et du genre sur les professions de l'enseignement. L'une des questions abordées dans cette recherche était de savoir comment ces facteurs interagissaient avec les aspirations professionnelles et les carrières des enseignants, administratifs et chefs d'établissement. Trois principales sources d'information ont été utilisées: un sondage par courrier de plus de 2000 personnes, couvrant différentes régions géographiques de l'Angleterre; des entretiens individuels avec une centaine d'enseignants de 18 écoles cibles, reparties sur les principales régions de l'Angleterre; des discussions avec des groupes de travail d'enseignants. De manière non surprenante, la réponse à la question ci‐dessus s'est avérée complexe. Néanmoins, cet article met en évidence un ensemble de thèmes significatifs à travers ce large groupe d'enseignants issus du primaire, du secondaire et d'institutions spécialisées.
La investigación que se presenta aquí formó parte de un largo estudio sobre el impacto que tenía la edad, discapacidad, diferencias de etnia y género en la profesión de maestro en Inglaterra. Una de las principales cuestiones a contestar en la presente investigación fue cómo estos factores interactúan en las aspiraciones profesionales de maestros, jefes del departamento y directores, se presentan en este artículo. Hubo tres principales fuentes de datos. Estas incluían: una amplia encuesta por correo la cual tuvo en cuenta diversas regiones de la geografía de Inglaterra, con cerca de unas 2000 personas encuestadas; entrevistas individuales cara a cara a unos 100 maestros en 18 estudios de casos de escuelas a través de todas las principales regiones de Inglaterra; y discusiones con grupos interesantes de maestros. No nos debe sorprender que las respuestas a las preguntas comentadas anteriormente fueran complejas de resolver. De todas formas las conclusiones del artículo dan luz a algunos de los temas significativos a través de la amplia muestra de maestros de escuelas de primaria, secundaria y escuelas especiales.
Die hier präsentierte Forschungsarbeit war Teil einer umfassenden Studie, die sich mit der Auswirkung von Alter, Behinderung, ethnischer Herkunft und Geschlecht auf den Lehrberuf in England auseinandersetzt. Die wesentliche Frage, die in dieser Forschungsarbeit gestellt wurde, lautete wie folgt: wie wirken sich genannte Faktoren auf Karriereaspirationen und Leistungen von Klassenlehrern, beförderten Lehrern und Schulleitern aus? Die Daten wurden aus drei Hauptquellen bezogen; dazu gehören: eine umfassende, geographisch breitgefächerte Postumfrage in England, auf die über 2000 Befragte antworteten; persönliche Gespräche mit über 100 Lehrern aus 18 zu Fallstudien herangezogenen Schulen in den Haupregionen Englands; und Diskussionen mit Lehrern, die bestimmte Interessengruppen vertreten. Die Antwort zu der oben genannten Frage war erwartungsgemäss komplex. Nichtsdestoweniger werden in dieser Arbeit einige der Themen hervorgehoben, die Lehrer aus dem Primär‐, Sekundär‐ und Sonderschulbereich für besonders erwähnenswert hielten. 相似文献
