Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe

Plan de acciones para mitigar la contaminación del río Cazones en el tramo Coatzintla-Cazones, Veracruz, México

Trabajo Recepcional presentado a la Facultad de Ingeniería Química de la Universidad Veracruzana. Región Xalapa

SARS-CoV-2: basic concepts, origin and treatment advances

The first cases of COVID-19, caused by the virus called SARS-CoV-2, were recorded in Wuhan, China, in December 2019; however, its transmission ability caused for the infection to be practically present throughout the world six months later. The origin of the virus appears to be zoonotic; it has been proposed that it comes from a bat and that it may have had an intermediate host that led to its introduction in the human population. SARS-CoV-2 is an enveloped virus, with a positive single-stranded RNA genome, and it binds to the angiotensin-converting enzyme, present in susceptible cells, to infect the human respiratory system. Although other coronaviruses have been previously known, they have not had the same impact, and, therefore, research on pharmacological treatments is not sufficiently developed to face the current challenge. Almost since the beginning of the epidemic, several molecules have been proposed for the treatment of infection; however, there is not yet a drug available with sufficient effectiveness for treatment. This review describes SARSCoV- 2 main characteristics, its replicative cycle, its possible origin and some advances in the development of antiviral treatments

Las vesículas extracelulares y su papel en la salud y el cáncer

La comunicación entre células es esencial para la homeostasis de los organismos. Existen al menos cinco tipos de comunicación celular (Tabla 1) que en su mayoría ocurren cuando algunas células liberan moléculas llamadas ligandos que actúan sobre los receptores proteicos de otras células, (blanco o diana). A pesar de los diversos estudios sobre este mecanismo, quedan algunas dudas por responder. ¿Cómo logran llegar con especificidad las moléculas a su destino celular al ser liberadas las moléculas al torrente sanguíneo y linfático? ¿cómo evaden al sistema inmunológico y a enzimas degradadoras como proteasas? Este paradigma está siendo abordado con el estudio de estructuras derivadas de los sistemas celulares, denominadas vesículas extracelulares. En este trabajo se revisa el estado actual del conocimiento relacionado con las vesículas extracelulares y su papel en la salud y cancer

Percepciones de las culturas emergentes en el contexto de la enseñanza universitaria

La universidad como escenario fundamental para el abordaje de saberes a partir de quienes en ella intervienen, convoca permanentemente a docentes y alumnos a reflexionar en torno a la enseñanza dando cuenta de la didáctica, la pedagogía, el papel de la educación superior en la sociedad y las prácticas resultantes de las interacciones entre los actores del aula universitaria. Éste trabajo de investigación encontró necesario dar una mirada al joven estudiante concibiéndolo como un sujeto cultural, el cual representa a diferentes grupos, expresando sus intereses en múltiples formas y cómo estos intereses son percibidos al interior del contexto áulico, particularmente en relación con las prácticas de enseñanza. Por lo anterior se planteó como objetivo fundamental, identificar las percepciones de profesores y estudiantes sobre las culturas emergentes o tribus urbanas en el ámbito del salón de clases en articulación con las prácticas de enseñanza, para tal fin el proceso de investigación se basó en un diseño de naturaleza descriptiva y exploratoria utilizando como técnica de recolección de información la entrevista semi- estructurada la cual se aplicó a cuatro docentes y ocho estudiantes de la facultad de Artes de la Pontifica Universidad Javeriana. En los resultados se evidenció que en el aula universitaria existe una cierta estigmatización al joven perteneciente a las culturas emergentes. Adicionalmente, se encontró la necesidad de que el docente esté más permeado por dichas culturas con el propósito de proponer las estrategias pertinentes en sus prácticas de enseñanza. De la misma manera se evidenció que las relaciones en el aula universitaria están condicionadas por el imaginario que los actores posean de las diferentes culturas.The University as a fundamental stage for the approach of knowledge from those who are involved in it. It permanently invites teachers and students to reflect on teaching, taking into account didactics, pedagogy, the role of higher education in the society and practices resulting from the interactions between the players in the University classroom. This research paper found the need of taking a look at the young student, conceiving him/her as a cultural subject which represents various groups expressing their interests in multiple forms and how they are perceived in the interior of the university context, in relation to the teaching practices. Therefore arose the next objective: to identify the perceotion of teachers and students about the emerging cultures or urban tribes in the classroom in relation with the teaching practices, for such purpose the research process was qualitative ordered with a design of description and exploratory technique. Collecting information from the semi-structured interview which was applied to four teachers and eight students of the Faculty of Arts at Javeriana University. The results showed that there is a certain stigma in the University classroom towards the young belonging to the emerging cultures. In addition, we found the need for the teacher to be more permeated by these cultures in order to propose appropriate strategies in their teaching practices. Similarly the results showed that the relations in the University classroom are conditioned by the percepctions that the teachers and students have from them

Effectiveness of PCR primers for the detection of occult hepatitis B virus infection in Mexican patients.

BACKGROUND:Occult hepatitis B infection (OBI) is defined as the presence of hepatitis B virus (HVB) DNA in the liver of HBsAg negative individuals with or without detectable viral DNA in serum. OBI is a diagnostic challenge as it is characterized by a very low viral load, intermittently detectable through time. Individuals with OBI can develop chronic hepatic disease, including liver cirrhosis and hepatocellular carcinoma. The aim of this work was to produce tools to improve OBI detection of the HVB genotypes prevalent in Mexico. METHODS:We designed and tested primers to detect OBI in serum samples by nested and real-time PCR. Conserved sites in the viral genome were determined by alignment of the most frequent HBV genotypes in Mexico (H, G/H, F and D) and primers spanning the entire viral genome were designed for first round and nested PCR. Primers were tested in serum samples of 45 patients not co-infected with hepatitis C virus or with HIV, out of a group of 116 HBsAg (-)/anti-HBc (+) individuals. Primers were also tested in a control group with chronic HBV. Nested PCR products obtained from HBsAg (-)/anti-HBc (+) were sequenced and used to design primers for real-time PCR (SYBR Green). RESULTS:The most effective primer pairs to detect HBV products by nested PCR targeted ORF regions: PreS2/P, S/P, X/PreC, and C; while by real-time PCR they targeted ORF regions PreS2/P, S/P, X, and C. Out of the 45 HBsAg (-)/anti-HBc (+) patients tested, the viral genome was detected in 28 (62.2%) and 34 (75.5%), with nPCR and real-time PCR respectively. CONCLUSION:Primers designed for real-time PCR detected up to 75.5% of suspected OBI Mexican patients, with or without liver disease, which represents an improvement from previous PCR strategies

Subtotal parotidectomy with facial nerve preservation. A case report

<p><strong>Background</strong></p><p>We present a clinical case of a 60-year-old female patient with a parotid tumor which is scheduled for partial resection and an adequate dissection of the nerve and identification of the 5 branches is observed. In this article we try to present the theory and its adequate application to clinical practice in a surgery as delicate as a superficial parotidectomy. An adequate post-surgical performance of the patient was demonstrated and trans-surgical images and subsequent results are presented.</p><p> </p><p><strong>Keywords: </strong>Subtotal parotidectomy, Facial nerve, Pleomorphic adenoma.</p&gt