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Permanent URI for this collectionhttps://hdl.handle.net/11285/345284
Artículo científico o editorial en una publicación periódica académica sujeto a revisión de pares. Cumple con los índices internacionales o bases de datos de amplia cobertura, como el listado del Current Contents, ISI WEB of Knowledge (http://isiknowledge.com/) e índice de revistas mexicanas de CONACYT (www.conacyt.mx/dac/revistas). Éstos indizan y resumen los artículos de revistas seleccionadas, en todas las áreas del saber.
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- Antimicrobial and antiproliferative activity of essential oil, aqueous and ethanolic extracts of Ocimum micranthum Willd leaves(Springer Open, 2018-02-08) Caamal-Herrera, Isabel O; Carrillo-Cocom, Leydi M; Escalante-Réndiz, Diana Y; Aráiz-Hernández, Diana; Azamar-Barrios, José A; Tecnológico de MonterreyAbstract Background Ocimum micranthum Willd is a plant used in traditional medicine practiced in the region of the Yucatan peninsula. In particular, it is used for the treatment of cutaneous infections and wound healing, however there are currently no existing scientific studies that support these applications. The aim of the present study was to evaluate the antimicrobial and the in vitro proliferative activity (on healthy mammalian cell lines) of the essential oil and extracts (aqueous and ethanolic) of this plant. Methods The minimal inhibitory concentration (MIC) of essential oil and aqueous and ethanolic extracts of Ocimum micranthum leaves against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Candida albicans was determined using the microdilution technique. The in vitro proliferative activity of human fibroblast (hFB) and Chinese hamster ovary (CHO-K1) cells treated with these extracts was evaluated using the MTT test. The hFB cell line was also evaluated using Trypan Blue assay. Results Candida albicans was more susceptible to the ethanolic extract and the aqueous extract (MIC value of 5 μL/mL and 80 μL/mL respectively). In the case of Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa, the MIC of the aqueous and ethanolic extract was 125 μL/mL. The aqueous extract showed a significant (p < 0.05) antiproliferative effect on hFB cells at a concentration of 4%, with cell proliferation percentage values of 73.56% and 20.59% by MTT method and Trypan Blue assay, respectively; the same effect was observed for the ethanolic extract at concentration from 0.06% to 0.25% using MTT method and at a concentration from 0.125% to 0.25% using Trypan Blue assay. In CHO-K1 cells an antiproliferative effect was observed at a concentration of 8% of aqueous extract and from 0.06% to 0.25% of ethanolic extract using the MTT method. Conclusion These assays showed that low concentrations of essential oil and extracts of Ocimum micranthum leaves are sufficient to cause an antiproliferative effect on the hFB cell line but do not produce an antimicrobial effect against the microorganisms evaluated. More studies are necessary to improve understanding of the mechanism of action of the compounds implicated in the bioactivities shown by the crude extracts.
- Safety of targeting tumor endothelial cell antigens(Springer Open, 12/04/2016) Wagner, Samuel C.; Riordan, Neil H.; Ichim, Thomas E.; Szymanski, Julia; Ma, Hong; Perez, Jesus A.; López, Javier; Plata Muñoz, Juan J.; Silva, Francisco; Patel, Amit N.; Kesari, SantoshAbstract The mechanisms underlying discrimination between “self” and “non-self”, a central immunological principle, require careful consideration in immune oncology therapeutics where eliciting anti-cancer immunity must be weighed against the risk of autoimmunity due to the self origin of tumors. Whole cell vaccines are one promising immunotherapeutic avenue whereby a myriad of tumor antigens are introduced in an immunogenic context with the aim of eliciting tumor rejection. Despite the possibility collateral damage to healthy tissues, cancer immunotherapy can be designed such that off target autoimmunity remains limited in scope and severity or completely non-existent. Here we provide an immunological basis for reconciling the safety of cancer vaccines, focusing on tumor endothelial cell vaccines, by discussing the following topics: (a) Antigenic differences between neoplastic and healthy tissues that can be leveraged in cancer vaccine design; (b) The layers of tolerance that control T cell responses directed against antigens expressed in healthy tissues and tumors; and, (c) The hierarchy of antigenic epitope selection and display in response to whole cell vaccines, and how antigen processing and presentation can afford a degree of selectivity against tumors. We conclude with an example of early clinical data utilizing ValloVax™, an immunogenic placental endothelial cell vaccine that is being advanced to target the tumor endothelium of diverse cancers, and we report on the safety and efficacy of ValloVax™ for inducing immunity against tumor endothelial antigens.
- Pedagogies for the open knowledge society(Springer Open, 2016-08-31) Ricaurte Quijano, Paola; PAOLA RICAURTE QUIJANO;352335; Tecnologico de MonterreyLearning challenges within the knowledge society cannot be limited to the technological dimension. Learning and education are embedded in economic, political and cultural contexts. Pedagogies reflect this social condition. Consequently we need to situate the pedagogical practices on a wider debate regarding their place in the global system of knowledge production. Some questions are relevant in assessing these practices: What is the sense of learning in the knowledge society? How this technological paradigm modifies our conception of learning and education? How pedagogies are related to technology and the global system of knowledge production? What principles are associated with these proposals? Through a case study of two learning environments, Wikipedia and Google, we compare the two models and the values, principles and competences associated to each of them.
- Molecular evolution and expression profile of the chemerine encoding gene RARRES2 in baboon and chimpanzee(Springer Open, 12/06/2015) González Alvarez, Rafael; Garza Rodríguez, María; Delgado Enciso, Iván; Treviño Alvarado, Víctor M.; Canales Del Castillo, Ricardo; Martínez De Villarreal, Laura E.; Lugo Trampe, Ángel; Tejero, María E.; Schlabritz Loutsevitch, Natalia E.; Rocha Pizaña, María; Cole, Shelley A.; Reséndez Pérez, Diana; Moises Alvarez, Mario; Comuzzie, Anthony G.; Barrera Saldaña, Hugo A.; Garza Guajardo, Raquel; Barboza Quintana, Oralia; Rodríguez Sánchez, Irám P.Abstract Background Chemerin, encoded by the retinoic acid receptor responder 2 (RARRES2) gene is an adipocytesecreted protein with autocrine/paracrine functions in adipose tissue, metabolism and inflammation with a recently described function in vascular tone regulation, liver, steatosis, etc. This molecule is believed to represent a critical endocrine signal linking obesity to diabetes. There are no data available regarding evolution of RARRES2 in non-human primates and great apes. Expression profile and orthology in RARRES2 genes are unknown aspects in the biology of this multigene family in primates. Thus; we attempt to describe expression profile and phylogenetic relationship as complementary knowledge in the function of this gene in primates. To do that, we performed A RT-PCR from different tissues obtained during necropsies. Also we tested the hypotheses of positive evolution, purifying selection, and neutrality. And finally a phylogenetic analysis was made between primates RARRES2 protein. Results RARRES2 transcripts were present in liver, lung, adipose tissue, ovary, pancreas, heart, hypothalamus and pituitary tissues. Expression in kidney and leukocytes were not detectable in either species. It was determined that the studied genes are orthologous. Conclusions RARRES2 evolution fits the hypothesis of purifying selection. Expression profiles of the RARRES2 gene are similar in baboons and chimpanzees and are also phylogenetically related.
- Knowledge-based development as a new economic culture(Springer Open, 2015-10-15) Carrillo Gamboa, Francisco J;0000-0001-7669-2005; FRANCISCO JAVIER CARRILLO;30245; Tecnologico de MonterreyAbstract This is a theoretical research paper that aims to make the case for the major cultural evolution underlying the transition from industrial to knowledge societies. The approach followed consists of a theoretical analysis of the re-definition of production factors as well as the output variables to characterize and measure social worth. A major emphasis is placed upon economy as culture, one where not just financial and material capital, but all worthy value dimensions are given due consideration. As a result, knowledge-based value is characterized through represented experience, i.e., acquired symbols and preference criteria. The nature of k-based as opposed to material-based economics is central to this discussion. The paper concludes that a new economic culture shall evolve in parallel to the emergence of knowledge cities and societies. The ‘knowledge’ attribute of knowledge cities relies on the capacity to balance all societal values into an equitable and sustainable dynamic equilibrium. The background section provides an introduction to the evolving concept of knowledge-based, in contrast to the prevailing material-based paradigm of industrial culture. The approach section explores the behavioral and social bases of such distinction. The discussion section concentrates on the economic foundations of knowledge-based value generation. Finally, the conclusions draw on the implications of the above discussion for economic science and the emerging knowledge-based culture.
- Analysis and experimental evaluation of the frequency response of an indoor radiating cable in the UHF band(Springer Open, 10/02/2015) Seseña Osorio, Jorge A.; Zaldívar Huerta, Ignacio E.; Aragón Zavala, Alejandro; Castañón Ávila, Gerardo A.Abstract We present the modeling of the frequency response of the channel for a radiating cable system by using an autoregressive model for an indoor environment. The coefficients of the autoregressive model are determined from the experimental channel frequency response. Measurements were carried out in an indoor environment, in particular on the second floor of a university building in the frequency range of 1.3 to 1.8 GHz by using a vector network analyzer. It is demonstrated that the use of a second-order model provides a better representation of the behavior of the channel. In this context, the coherence bandwidth and the rms delay spread show dependence with the receiver position along the radiating cable length. This dependence is crucial and must be taken into account in the design and study of broadband systems with mobility because the rms delay spread and coherence bandwidth are used to describe the time dispersion and the frequency selectivity of the multipath fading channels, respectively.
- TETX: a novel nuclear selection marker for Chlamydomonas reinhardtii transformation(Springer Open, 2015-04-15) García-Echauri, Sergio A; Cardineau, Guy A;0000-0001-5144-7660; SERGIO ANGEL GARCIA ECHAURI;209658; GUY CARDINEAU;344537Abstract Background Transformation of microalgae to obtain recombinant proteins, lipids or metabolites of economic value is of growing interest due to low costs associated with culture growth and scaling up. At present there are only three stable nuclear selection markers for the transformation of Chlamydomonas reinhardtii, which is the most commonly transformed microalgae, specifically: the aminoglycoside phosphotransferaseses aph7and aphVIII and the phleomycin resistance ble gene. As several microalgae are resistant to some of the antibiotics associated with the mentioned resistance genes, we have developed another alternative, tetX, a NADP-requiring Oxidoreductase that hydroxylates tetracycline substrates. We provide evidence that tetX can be used to obtain nuclear transformants of Chlamydomonas reinhardtii. Results We obtained nuclear transformants harbouring the tetX gene under the control of beta 2 tubulin or HSP70ARBCS2 promoters at an efficiency of transformation of 3.28 and 6.18 colony forming units/μg DNA respectively. This is the first report of a eukaryotic cell transformed using tetracycline as a selectable marker. Conclusions We developed a protocol for the nuclear transformation of Chlamydomonas reinhardtii using tetX as a selectable marker that confers stable resistance to tetracycline up to 100 μg/mL. We believe tetX can be used to transform Chlamydomonas reinhardtii chloroplasts, related microalgae and other aerobic organisms sensitive to any tetracycline antibiotic.
- Adult white New Zealand rabbit as suitable model for corneal endothelial engineering(Springer Open, 04/02/2015) Valdéz García, Jorge E.; Lozano Ramirez, Juan F; Zavala, JudithAbstract Background Corneal endothelium engineering is focused in producing transplantable cell sheets to overcome the shortage of corneal graft tissue donors for the treatment of corneal blindness. For this purpose, the use of a proper animal model plays a key role. Corneal parameters of White New Zealand rabbits such as endothelial cell density, central corneal thickness, and corneal diameter decrease with age, similarly as in humans. However, as opposed to humans, they retain the ability to restore their corneal endothelium after injury. Therefore, they are considered as an inappropriate corneal endothelial wound healing model. Findings Here we analyze the corneal endothelium mitotic ability of White New Zealand rabbits aged 3, 6, 12 and 18 months, 36 and 72 hours after thermal injury. The highest mitotic activity was observed in the 3-month rabbits 36 h after wounding. Rabbits of 12 months registered decreased mitotic activity and those of 18 months did not show mitotic activity 72 h after injury. Conclusions These results propose that rabbits of 18 months represent a suitable model for human corneal endothelium engineering research.
- Self-motivation challenges for student involvement in the Open Educational Movement with MOOC(Springer Open, 2015-01-15) García Espinosa, Brenda J.; Tenorio Sepúlveda, Gloria C.; Ramírez Montoya, María S.; Tecnologico de MonterreyAbstract This article attempts to answer the questions: What are the challenges, problems and obstacles of involving less self-motivated students in MOOCs and how do they relate to their learning connectivism? The correlations between connectivism and contextualized learning through a formative experience of the Open Educational Movement was analyzed in order to propose strategies that result in greater perseverance, active participation and retention of less self-motivated students in MOOCs. A mixed method approach was used to survey students, interview students and coordinators, and analyze relevant documents. The findings were classified as (1) Challenges: self-motivation, self-regulation abilities, extra time invested, release requirements, goals and inductive activities before the course opening, unsatisfactory identification of students, difficult activities, feedback monitoring and a platform incompatible with balancing its use with that of social networks; (2) Problems: limited information and communication technology skills, difficult feedback research in forums, uncertain peer feedback when not theory-based or scaffolded by teachers, scarce theoretical support in evidence portfolios and a lack of means to help low self-motivated or self-regulated students; (3) Main contextual obstacles: some students cannot count on their employers’ support or continuous technology access, some students basic wellbeing needs are not met, and inability to contextualize learning; (4) Connectivism: students’ motivation in the MOOC content and their expanding knowledge networks. Based on these findings, a MOOC design requirement template aimed at supporting students’ self-motivation and self-regulation through connectivism is provided.
- Gamification and service marketing(Springer Open, 04/11/2014) Conaway, Roger; Garay, Mario C.Abstract Our paper addresses the development of the gamification concept with business applications. We report on our survey of customers and managers seeking to participate in gamification on their websites. We examined both customer and manager perspectives and compare survey results in terms of service marketing and characteristics of consumers who engage with gamification platforms. Our data supported a design theory delineating four key characteristics in gamification platforms that attract consumers toward an enterprise’s website. Those features attract individuals through (1) Progress Paths, (2) Feedback and Reward, (3) Social Connection, and (4) Attractiveness of the site. Results from the managers’ survey reflected key characteristics that must exist for implementation of a gamification platform. The data revealed a particular demographic profile of a gamification individual drawn to a website. These findings may help company managers who wish to adopt a gamification platform in the future.