Diseño de una práctica de química como proyecto de ciencias, procesos de extracción de proteínas

El desarrollo del Aprendizaje de ciencia, en los estudiantes de la Licenciatura de Educación Secundaria con la especialidad en Química, se lleva a cabo empleando como una buena técnica la de aprendizaje basado en proyectos, el proyecto presentado como una propuesta es la extracción de compuestos orgánicos, para esto se diseñó una práctica de extracción de proteínas por dos métodos, uno convencional que es la precipitación isoeléctrica y otro casi desconocido como método de extracción de proteínas, que es el de miscelización. La experimentación práctica que se diseñó para tratar de establecer como obligada para el final de curso de ciencias de educación secundaria, ya que integra varios componentes que permiten aprender tanto química como procesos fisicoquímicos de extracción, además de que la medición de pH hace que se comprenda mejor al hacer curvas base de los procesos de extracción, esto es debido a que se emplean dos métodos que permiten establecer diferencias de extracción de proteína de fuentes como las leguminosas y de pastas residuales de oleaginosas. Se encontró relevante que ambos procesos de extracción son factibles para obtener proteína en alta concentración, y con ambos procesos parece ser factible obtener no solo concentrados, sino aislados proteicos.The development of learning science, students of the Bachelor of Secondary Education with a specialization in Chemistry, is performed using a good technique of project-based learning, the project presented as a proposal is the removal of organic compounds to practice this protein extraction by two methods was designed, which is a conventional isoelectric precipitation and other almost unknown as protein extraction method, which is to miscelización. Practical experimentation which was designed to try to establish as a must for the end of year high school science education, because it integrates several components that allow you to learn both chemical and physicochemical extraction processes, in addition to the measurement of pH makes you understand better to make curves based extraction processes, this is due to two methods for extraction differentiate sources of protein such as legumes and oil waste pastes are used. It was found that both processes relevant extraction are feasible for protein in high concentration, and both processes appear to be feasible to obtain not only concentrated, but protein isolates

Actividad antibacteriana, hemolítica y coagulante del veneno crudo de la serpiente Crotalus atrox in vitro

Diversos estudios demuestran el efecto antibacteriano y hemolítico del veneno de Bothrops atrox, pero se desconoce si el veneno de la especie Crotalus atrox en cautiverio, perteneciente a la misma familia y con amplia distribución en el país, tiene efectos similares. En este trabajo se evaluó la actividad antibacteriana, hemolítica y coagulante del veneno crudo de C. atrox mediante ensayos in vitro. Se obtuvo una concentración de 40 μg/μl de proteína en el veneno. El veneno crudo (60 µg/µl) presentó actividad antibacteriana determinada por los halos de inhibición en Staphylococcus aureus y Escherichia coli. Se observaron halos de hemolisis alfa de ~20 mm con 300 a 900 μg/μl de veneno. La actividad coagulante se presentó hasta las 24 h después de la aplicación del veneno. Se realizó una electroforesis para la obtención del patrón proteico del veneno y se mostró una banda de 130 kDa, la cual podría pertenecer a algún miembro de la familia de la L-aminoácido oxidasa y otras por debajo de los 15 kDa, donde podrían estar incluidas la crotamina y la fosfolipasa A₂.Several studies show that Bothrops atrox venom has antibacterial and hemolytic activities; however, whether the venom from Crotalus atrox –a species that belongs to the same family and is widely distributed in our country– has similar effects, remains unknown. In this work, the antibacterial, hemolytic and clotting activities of crude C. atrox venom were evaluated in vitro. The crude venom contained 40 μg/μl protein. It displayed Staphylococcus aureus and Escherichia coli inhibition at 60 µg/µL, and ~20 mm alpha hemolysis at 300-900 μg/μl. Clotting activity appeared later, 24 h post exposition to the venom. Electrophoretic separation of the venom protein content revealed a 130 kDa band, which could belong to a member of L-amino acid oxidase family, and a sub-15 kDa band, wich could comprise crotamin and phospholipase A₂

Algunas noticias y novedades del género Genista L. en el SW de Europa

Some news of the genus Genista L. in the Southwest of Europe. Two new hybrids are described in the genus Genista L. (Fabaceae): G. × prestameroi (G. scorpius subsp. scorpius × G. teretifolia Willk.) and G. × aseginolazae (G. carpetana × G. hystrix). Also the known distribution area of G. germanica L. is enlarged in the south west of Europe and it shows a list of the hybrids of this genus known in the Iberian Peninsul

Cómo perciben la evaluación por una prueba objetiva de la asignatura de LIC II, los estudiantes de segundo semestre de Biología de la FES Iztacala

En este trabajo se valoró la percepción que tienen los estudiantes de segundo semestre de la carrera de Biología de la FESI con respecto a la evaluación mediante una prueba objetiva en la asignatura de Laboratorio de Investigación Científica II, ya que se sabe que la evaluación debe ser objetiva y evidenciar el manejo de habilidades, destrezas y competencias. Se construyó un instrumento de 24 ítems, agrupados en 2 dimensiones: Percepción cognitiva del examen y reacciones del stress ante el examen. El instrumento fue validado por contenido, aplicación y constructo en una muestra de 68 alumnos voluntarios. El alfa de Cronbach dio un valor de 0.85, un índice KMO de 0.849, la esfericidad de Bartlett de 0.003. Con respecto a los estudiantes, éstos contestaron que los ítems muestran concordancia con la asignatura, el nivel de aprendizaje y los objetivos de su aplicación; y el nivel de estrés afecta el aprendizaje.In this work, the perception of students of the second semester of the career of Biology from the FESI with regard the evaluation across an objective test in the subject of Laboratorio de Investigación Científica II was valorated, since it is known the evaluation must be objective and evidence the management of skills, abilities and competencies. An instrument of 24 items, grouped in two dimensions was constructed: Cognitive perception of the test and stress reactions to the test. The instrument was validated by content, application and construct, in a sample of 68 voluntary students. The value of Cronbach´s Alpha was 0.85, the KMO index was 0.849 and the Bartlett´s sphericity was 0.003. With regard to the students, they answered that the items show concordance with the subject, the learning level and the objectives of its application, and the level stress affects learning

Lipidomics as a Tool in the Diagnosis and Clinical Therapy

The lipids are essential compounds of cells, with biochemical and structural properties. Lipids are classified according to their chain length or saturation levels and biogenesis. Lipidomics is a spectroscopic and spectrometric technique, like Mass Spectrometry and Nuclear Magnetic Resonance, as well as bioinformatics to quantify and characterize the lipid profile. Lipidomics enables the fundamental understanding of lipid biology, the identification of drug targets for therapy, and the discovery of lipid biomarkers of disease cohorts. Therefore, lipidomics allows knowing the diagnosis and clinical follow-up in medical therapy towards any disease. In this way, the lipid profile allows us to monitor the administration of a clinical treatment and assertively diagnose human diseases

Pathogenic variant profile in DNA damage response genes correlates with metastatic breast cancer progression-free survival in a Mexican-mestizo population

IntroductionMetastatic breast cancer causes the most breast cancer-related deaths around the world, especially in countries where breast cancer is detected late into its development. Genetic testing for cancer susceptibility started with the BRCA 1 and 2 genes. Still, recent research has shown that variations in other members of the DNA damage response (DDR) are also associated with elevated cancer risk, opening new opportunities for enhanced genetic testing strategies.MethodsWe sequenced BRCA1/2 and twelve other DDR genes from a Mexican-mestizo population of 40 metastatic breast cancer patients through semiconductor sequencing.ResultsOverall, we found 22 variants –9 of them reported for the first time– and a strikingly high proportion of variations in ARID1A. The presence of at least one variant in the ARID1A, BRCA1, BRCA2, or FANCA genes was associated with worse progression-free survival and overall survival in our patient cohort.DiscussionOur results reflected the unique characteristics of the Mexican-mestizo population as the proportion of variants we found differed from that of other global populations. Based on these findings, we suggest routine screening for variants in ARID1A along with BRCA1/2 in breast cancer patients from the Mexican-mestizo population

Ultraviolet Radiation and Its Effects on Plants

Ultraviolet radiation is a portion of the electromagnetic spectrum ranging from 10 to 400 nm, classified into three main categories: UV-A (320–400 nm), UV-B (280–320 nm), and UV-C (100–280 nm). The UV radiation from the sun that crosses the atmosphere and reaches the earth’s surface is composed largely of UV-A radiation (95%) and, to a lesser extent, UV-B (5%), which is normally filtered by stratospheric ozone. With the thinning of the ozone layer, UV-B radiation penetrates deeper into the earth’s surface, where it becomes dangerous due to its high energy content that acts at the molecular level, affecting the cycles of carbon, nitrogen, and other elements, thus, having a direct impact on global warming. On the other hand, UV radiation alters numerous essential organic compounds for living organisms. Since its discovery, it has been established that e UV-B causes alterations in plant development and metabolism, both primary and secondary. In this chapter, we summarize the current knowledge about the effects of UV radiation on the morphological, biochemical, and genetic processes in plants

COVID-19: Una mirada interdisciplinaria a la pandemia

La pandemia de COVID-19 (Acrónico del inglés coronavirus disease) fue declarada por la OMS el 11 de marzo de 2020; se trata de una enfermedad altamente infecciosa causada por el virus SARS- a pandemia de COVID-19 (acrónimo del inglés coronavirus disease) CoV-2, la cual se detectó por primera vez en la ciudad china de Wuhan (provincia de Hubei) en diciembre de 2019. El exacerbado contagio a nivel global y en escalas signifcativas ha comenzado a generar serios problemas sanitarios y económicos en todos los países. También se han generado diversos debates sobre el origen, causas, impactos y medidas en torno a esta crisis global. Desde la Universidad Dr. José Matías Delgado, a través de su Centro de Investigaciones en Ciencias y Humanidades (CICH), proponemos esta reflexión interdisciplinaria para generar un registro de nuestra preocupación científica y para compartir con la comunidad académica y la sociedad algunas ideas importantes, desde reflexiones teóricas hasta propuestas de abordaje. El COVID-19 como fenómeno epidemiológico está impactando en la vida de diversos sectores, generando un posible cambio que deje huella signifcativa y profunda. Estamos ante la gran crisis del siglo XXI, y ésta comienza a transformar la realidad doméstica, social, cultural, política y económica. Asimismo, se desarrollan serios desequilibrios y conflictos. El aislamiento y las cuarentenas aplicadas para lograr el aislamiento que corte el contagio comienzan a deteriorar el bienestar psicológico de los ciudadanos, el comercio informal y la microeconomía, lo que podría modificar el paisaje sociológico contemporáneo. En estas reflexiones que presentamos desde el CICH apuntamos ideas claves desde la perspectiva científica, ideas necesarias y fundamentales para abordar y sobreponernos a la crisis, y sobre todo una reflexión para recuperar la anhelada normalizaciónBoletín Especial del Centro de Investigaciones en Ciencias y Humanidades (CICH)

Micro-RNAs as Potential Predictors of Response to Breast Cancer Systemic Therapy: Future Clinical Implications

Despite advances in diagnosis and new treatments such as targeted therapies, breast cancer (BC) is still the most prevalent tumor in women worldwide and the leading cause of death. The principal obstacle for successful BC treatment is the acquired or de novo resistance of the tumors to the systemic therapy (chemotherapy, endocrine, and targeted therapies) that patients receive. In the era of personalized treatment, several studies have focused on the search for biomarkers capable of predicting the response to this therapy; microRNAs (miRNAs) stand out among these markers due to their broad spectrum or potential clinical applications. miRNAs are conserved small non-coding RNAs that act as negative regulators of gene expression playing an important role in several cellular processes, such as cell proliferation, autophagy, genomic stability, and apoptosis. We reviewed recent data that describe the role of miRNAs as potential predictors of response to systemic treatments in BC. Furthermore, upon analyzing the collected published information, we noticed that the overexpression of miR-155, miR-222, miR-125b, and miR-21 predicts the resistance to the most common systemic treatments; nonetheless, the function of these particular miRNAs must be carefully studied and further analyses are still necessary to increase knowledge about their role and future potential clinical uses in BC