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Synthesis and evaluation of novel heterocyclic ferrocenyl chalcone hybrids as possible anticancer and antioxidant agents
(2023-06-02)
Breast cancer is currently the most diagnosed cancer in women, with 287,850 new cases estimated in 2022, as reported by the American Cancer Society. Therefore, finding an effective treatment for this disease is imperative. ...
Applications of two-dimensional tungsten disulfide and boron nitride nanosheets in self-powered photodetectors and memory devices
(2023-08-22)
Since single-layer graphene was isolated from highly-oriented pyrolytic graphite in 2004, it led to the beginning of a new revolution in materials science due to its many applications in nano-electronic device technology. ...
Studies on multifunctional materials applied to energy storage
(2023-08-07)
Structure, phonon, and energy storage density in Sr2+-substituted lead-free ferroelectric Ba1-;xSrxTiO3 (BSTx) for compositions x= 0.1, 0.3, and 0.7 were investigated ...
Synthesis and characterization of cathode materials for lithium-sulfur batteries
(2023-07-31)
Lithium-sulfur (Li-S) batteries have attracted considerable interest as next-generation high-density energy storage devices. However, their practical applications are limited due to rapid capacity fading when cycling cells ...
Molecular mechanisms underlying temperature-dependent synaptic growth at the Drosophila melanogaster neuromuscular junction
(2023-08-17)
There is clear evidence that Earth's temperature is rising at an unprecedented rate. While consequences on ecosystems are being extensively studied, little is known about the consequences of temperature on the nervous system of ectothermic animals. Using the stereotyped synapse found at the Drosophila neuromuscular junction (NMJ), we asked how rearing temperature (15°C, 25°C, 29°C) can affect synaptic growth. We observed an increase in the number of synaptic boutons in animals reared at higher temperature. Indeed, animals reared at 29°C had a 100% increase in synaptic growth when compared to animals reared at 15°C. Interestingly, we found that from the two motor neurons that innervating the muscle, the number of boutons from the Is motor neuron increased with temperature while the boutons from the Ib motor neuron remained constant. This result indicates that motor neurons might be differentially sensitive to the changes in temperature.<br /> <br /> We looked for the molecular mechanisms that regulate temperature-dependent synaptic growth. We identified that autophagy was important for this regulation. Autophagy mutants showed a temperature-independent undergrowth, where there was a reduction in the Is boutons, while the Ib boutons remained constant through the rearing temperatures. In addition, with the use of Lysotracker and the p62 marker, we identified that the levels of autophagy changed at different rearing temperatures. Afterwards we found that the autophagy target, Highwire (Hiw), an E3 ubiquitin ligase, is a key regulator of temperature-dependent synaptic growth. Hiw is a negative regulator of synaptic growth, and its mutation induced a temperature-independent overgrowth phenotype. In addition, we found two important MAPKKK pathways that are important for regulation of synaptic growth at 15°C and 29°C. The first is the Wallenda-P38b pathway which is important for the addition of Is boutons of animals reared at 29°C. The second is the ASK1-JNK-c-Jun pathway, which is important for suppressing synaptic growth in animals reared at 15°C. Also, we found that constitutive activation of the insulin pathway in animals reared at 15°C increases the total number of synaptic boutons, but activation of the same pathway at 25°C does not affect synaptic growth. We hypothesize that temperature-dependent synaptic growth is regulated by global mechanisms like autophagy and the ubiquitin proteosome system that regulate the activation of stress response components, like the MAP kinase pathways. By changing the rearing temperature, we have identified novel roles for signaling pathways that were previously described to regulate synaptic growth in loss-of function or gain-of-function mutant backgrounds....
Molecular mechanisms of intestinal organogenesis: A transcriptomic approach
(2023-06-02)
Organogenesis is a process normally reserved for developing organisms, however, some adult organisms are capable of such a feat. Adult sea cucumbers, in the highly regenerative clade Echinodermata, can undergo intestinal organogenesis after a process of evisceration where the intestine is severed then expelled through the cloaca. Studying this phenomenon has implications in regenerative biology to help discover the cellular and molecular processes that allow some species to regenerate better than others. Also, the field of regenerative medicine can benefit by enhancing existing biomedical applications, particularly that of intestinal tissue engineering. Thus, the sea cucumber Holothuria glaberrima is being used in this study to investigate intestinal organogenesis. The cellular properties of its regeneration have largely been elucidated, but the molecular mechanisms are now just starting to be unveiled. In this study we use a bioinformatic approach to investigate molecular mechanisms by collecting RNA-seq data from various early- and late-stage intestinal regenerate timepoints. These new timepoints not only contain newly sequenced tissue with luminal epithelium, but also samples that are spatially separated, i.e., anterior and posterior regenerates. Analyses from differential gene expression, gene set enrichment analyses, and weighted gene co-expression revealed differences in gene expression and molecular pathways operating at distinct temporal and spatial timepoints. For example, various signaling components of the Wnt/β-catenin pathway appear to be upregulated during early-stage rudiment regeneration, while signaling components of the Wnt/Planar Cell Polarity pathway are upregulated during late-stage regeneration in tissue that contains luminal epithelium. Even distinct gene ontological terms are functionally enriched in anterior regenerates that are not in posterior regenerates such as chromosome organization and cilium assembly. Altogether, this study demonstrates the diversity of molecular mechanism that occur during a dynamic process like intestinal organogenesis and serves as a baseline to guide future hypothesis-driven molecular studies....
Unraveling the role of RNA Binding Protein with Multiple Splicing (RBPMS) in ovarian cancer cells
(2023-01-17)
RNA-Binding Protein with Multiple Splicing (RBPMS) is member of a family of proteins that bind to nascent RNA transcripts and regulate their splicing, localization, and stability. Evidence indicates that RBPMS controls the ...
Repertorios de mejoramiento: Análisis crítico del discurso de mejoramiento cognitivo farmacológico en el contexto universitario
(2023-11-25)
En las últimas dos décadas, el mejoramiento cognitivo farmacológico (MCF) ha
aumentado a nivel mundial (Maier et al., 2018). Este fenómeno se observa mayormente en
ambientes de alta competitividad en las sociedades ...
El tríptico althusseriano : Louis Althusser se enuncia como otro en El porvenir es largo
(2023-08-15)
En 1980, Louis Althusser ahorca a su pareja Hélène Rytmann en su piso de la École Normale. El acto, declarado como un acto de demencia, lo destina al encierro del hospital psiquiátrico Sainte-Anne tras la declaración del ...
Conflictos organizacionales en una institución de educación superior en Puerto Rico: Estrategias de intervención
(2023-12-12)
Este estudio tuvo como propósito explorar el conflicto organizacional (CO) y estrategias utilizadas por personas directivas y empleadas de una institución de educación superior. Las preguntas del estudio fueron: (1) ¿Cuáles ...