Hydrazones as Singular Reagents in Asymmetric Organocatalysis

This Minireview summarizes strategies and developments regarding the use of hydrazones as reagents in asymmetric organocatalysis, their distinct roles in nucleophile–electrophile, cycloaddition, and cyclization reactions. The key structural elements governing the reactivity of these reagents in a preferred pathway will be discussed, as well as their different interactions with organocatalysts, leading to diverse activation modes. Along these studies, the synthetic equivalence of N-monoalkyl, N,N-dialkyl, and N-acyl hydrazones with several synthons is also highlighted. Emphasis is also put on the mechanistic studies performed to understand the observed reactivities. Finally, the functional group transformations performed from the available products has also been analyzed, highlighting the synthetic value of these methodologies, which served to access numerous families of valuable multifunctional compounds and nitrogen-containing heterocycles.Ministerio de Economía y Competitividad CTQ2013-48164-C2-1-P, CTQ201348164-C2-2-PEuropean FEDER fundsJunta de Andalucía 2012/FQM 107

An efficient method for miRNA detection and localization in crop plants

MiRNAs are a class of non-coding small RNAs (sRNAs) that are important regulators of gene expression at the post-transcriptional level by mRNA cleavage or translation inhibition. Another class of sRNAs are siRNAs, which also regulate gene expression but by causing DNA methylation. This epigenetic regulatory role has been observed for some miRNAs as well. The use of sRNAs allows the development of biotechnological applications in plants. To develop these types of applications, and to better understand the natural roles they play, it is important to be able to detect and to localize these sRNAs at the plant tissue level. Sometimes, in crop plants this can be challenging. Therefore, we developed a tissue printing hybridization protocol for easy and efficient detection of sRNAs and demonstrate this by the analysis of the spatio-temporal expression patterns of the miRNAs miR159 and miR164 in fruits of various crop plants. Moreover, we show the possibility to also detect the expression of miRNAs in fruit juice using a dot blot hybridization approach

Characterization of Patients with Guillain-Barré Syndrome in the General Hospital of Mexicali

Background: Guillain-Barré Syndrome is a progressive autoimmune polyradiculoneuropathy characterized by symmetrical flaccid paralysis accompanied by areflexia, hyporeflexia or hyperreflexia on rare occasions. Worldwide, it remains the first cause of flaccid paralysis. It is usually associated with infectious disease history; however, there are various clinical variants, each with a different outcome. Prognosis is usually good, although 20% of patients could suffer a severe clinical variant of Guillain-Barré Syndrome and 5% will die despite treatment. Methods: This is a cross-sectional study, including the records of hospitalized patients with Guillain- Barré Syndrome at Mexicali’s General Hospital within a five-year period. Results: In a five-year span there were 64 patients with Guillain-Barré Syndrome, most of the patients were men (70.3%), with age ranging 1 to 76 years. A total of 8 (12.5%) patients died, from which 7 (87.5%) required mechanical ventilation during hospitalization. Immunoglobulin therapy was provided to 56 (87.5%) patients, and 6 (10.7%) of them perished due to acute kidney injury. Conclusion: Guillain-Barré Syndrome is a common disease among male population, with no dominating onset age, however, leaning for the young and elder. Most of the patients that were hospitalized at the General Hospital of Mexicali had a history of previous infection (gastrointestinal, respiratory, or other infectious diseases). The need for mechanical ventilation represents a higher severity index, nonetheless, this does not mean that assisted ventilation is directly associated with mortality. As for treatment, immunoglobulin is the most common choice for therapy, though some of the patients died from acute kidney injury

Formaldehyde tert-butyl hydrazone as a formyl anion equivalent: asymmetric addition to carbonyl compounds

The asymmetric 1,2-addition of formyl anion equivalents to carbonyl compounds is a powerful synthetic tool that ideally provide access to highly functionalizable a-hydroxy aldehydes in an enantioselective fashion. In this context, the nucleophilic character of formaldehyde hydrazones, together with their remarkable stability as monomeric species, has been exploited for the functionalization of diverse carbonyl compounds, using initially auxiliary-based methodologies and, more recently, catalytic enantioselective versions. This feature article highlights our research progress employing formaldehyde tert-butyl hydrazone as a versatile formyl anion equivalent, in combination with bifunctional H-bonding organocatalysis. The design and optimization of different catalytic systems, focusing on a dual activation of both reagents, is reviewed, as well as the racemization free unmasking of the formyl group and representative product transformations for the construction of valuable, densely functionalyzed chiral building blocks.Ministerio de Economía y Competitividad de España (MINECO).CTQ2016-76908-C2-1-P y CTQ2016-76908-C2-2-PFondos FEDER de la Unión Europea y Junta de Andalucía. P18-FR-3531 y US126286

El mobile learning como metodología para favorecer la dimensión pragmática en preescolar

La tecnología se hace más presente y en la educación no es la excepción, la práctica educativa ha evolucionado a lo largo de los años gracias al contexto social en el que se desenvuelve; en consecuencia los escenarios perentorios que se presentan abren el panorama hacía un nuevo horizonte. Por lo que la presente investigación tiene como objetivo desarrollar e implementar aplicaciones de aprendizaje móvil para favorecer la dimensión pragmática en niños de preescolar, esto en una situación de pandemia y postpandemia, con el propósito de reconocer principalmente la importancia de la tecnología educativa como lo es el aprendizaje móvil en la educación actual, así como en qué medida se favorece el pensamiento crítico en niños de preescolar a partir de esta metodología. Será un estudio de enfoque mixto de tipo experimental que se aplica a una población de un Jardín de Niños llamado “Grillito” de la comunidad de las Chilitas, Zacatecas con una muestra de niños de 5 a 6 años de tercer grado de preescolar. Los resultados obtenidos a partir de la intervención pedagógica con una aplicación de aprendizaje móvil fueron positivos, sin embargo, no se alcanzó el nivel máximo de autonomía derivado de varios factores, por lo que es necesario darle seguimiento en los niveles educativos posteriores así como en el tiempo de intervención. Las principales dificultades presentes en el contexto son la diversidad de condiciones presentes en cada familia, la actitud del niño, la falta de cultura tecnología para el uso de dispositivos como medios de aprendizaje, la falta de capacitación de los padres de familia para fomentar ambientes tecnológicos en casa, entre otras. Por lo anterior, durante la aplicación de los diferentes momentos de la investigación se da cuenta de la necesidad de fomentar en primera instancia una cultura de tecnología educativa en casa y limitar el uso de dichos recursos en los niños como lo es en educación preescolar, puesto que los niños sólo lo conciben como una forma de entretenimiento y los padres de familia como una salida para mantener a los niños tranquilos; lo que implica darle continuidad a este propuesta de intervención de tal modo que se logre fortalecer los lazos de la educación con la tecnología educativa gracias a las bondades que genera en los niños y que la comunidad escolar perciba la importancia de incorporar los recursos contemporáneos no sólo en su vida diaria sino también en el ámbito educativo para dirigir la formación de ciudadanos preparados para enfrentar los retos contemporáneos, desde edades tempranas

Acute Liver Failure in Patients with Classic Heat Stroke

Background: Classic heat stroke is defined by a core temperature greater than 40° C, severe dehydration and neurological alterations. Patients with liver disease due to heat stroke have been described, mostly by exercise. Hepatic failure is defined as the presence of a coagulopathy accompanied by any degree of hepatic encephalopathy. The primary objective of the study lies in the fact that patients who developed acute liver failure during their hospital stay had a higher risk of mortality. Methods: A retrospective, analytical study of patients admitted to the General Hospital of Mexicali who suffered from classic heat stroke from March 2006 through August 2010, and a second period from June 2018 to August 2019. Results: Fifty patients were recruited, the group included 48 (96%) male, with a total of 10 fatalities, representing 20%. INR greater than 1.5, AST and ALT levels were not related to an increased mortality rate. Conclusion: Neither transaminase levels, nor liver failure, were related to a higher mortality rate in this cohort of patients with classic heat stroke

Bioactive Coatings on Porous Titanium for Biomedical Applications

Commercial pure titanium is a recognized and accepted material for cortical bone tissue substitution. However, stress-shielding phenomena and lack of osseointegration result in significant limitations. This work is focused on the achievement of an effective solution for both problems via fabrication of porous titanium substrates coated with bioactive glass. Substrates were obtained through the space holder technique giving values of stiffness and yield strength compatible with cortical bone tissue to reduce the stress-shielding phenomenon. Titanium substrates were coated with different number of layers of bioactive glass 45S5 by dripping sedimentation. The substrates porosity was characterized by different techniques. Ultrasound, compression and micro-mechanical testing were used for mechanical properties evaluation. After substrates coating, the infiltration ability, coating homogeneity and structural integrity (chipping and cracking) were evaluated for each coating layer. The chemical composition of coating and phases were studied before and after in vitro tests in Simulated Body Fluid. The results showed more homogenous coating, adherence and greater hydroxyapatite growth for the tri-layer system in both dense and porous samples. Besides, the relation of Ca/P was closed to that of stoichiometric hydroxyapatite in the human body. The coated porous titanium could be potentially used in load bearing partial implants with improved osseointegration.Ministry of Economy and Competitiveness of the State General Administration of Spain grant MAT2015-71284-

Whole-Genome Sequence of Serratia liquefaciens HUMV-21, a Cytotoxic, Quorum-Sensing, and Biofilm-Producing Clinical Isolate

A clinical isolate of Serratia liquefaciens (strain HUMV-21) was obtained from a skin ulcer of an adult patient. We report here its complete genome assembly using PacBio single-molecule real-time (SMRT) sequencing, which resulted in a single circular chromosome with 5.3 Mb. About 5,844 protein-coding genes are predicted from this assembly

Unidad Técnica de Geodesia, Geofísica y Magnetismo de Rocas: Laboratorio de Paleomagnetismo, Magnetismo de Rocas y Modelado Geomagnético

Trabajo presentado en la I Reunión Científica del Instituto de Geociencias (CSIC-UCM), los días 15 y 16 de septiembre de 2011.Peer reviewe