El presente artículo plantea como objetivo describir brevemente la problemática de la educación superior y el reto de la calidad. Para ello se abordan los principales desafíos que abordan las ...universidades principalmente relacionados con la calidad, así como los conceptos que más se relacionan con ella. De igual forma se realiza un recorrido por las aproximaciones al concepto de la calidad desde diferentes perspectivas multidimensionales, a partir de una visión intrínseca y extrínseca y como se complementa con otros abordajes sobre dicho concepto.
Liquid-liquid phase separation (LLPS) explains many intracellular activities, but its role in extracellular functions has not been studied to the same extent. Here we report how LLPS mediates the ...extracellular function of galectin-3, the only monomeric member of the galectin family. The mechanism through which galectin-3 agglutinates (acting as a "bridge" to aggregate glycosylated molecules) is largely unknown. Our data show that its N-terminal domain (NTD) undergoes LLPS driven by interactions between its aromatic residues (two tryptophans and 10 tyrosines). Our lipopolysaccharide (LPS) micelle model shows that the NTDs form multiple weak interactions to other galectin-3 and then aggregate LPS micelles. Aggregation is reversed when interactions between the LPS and the carbohydrate recognition domains are blocked by lactose. The proposed mechanism explains many of galectin-3's functions and suggests that the aromatic residues in the NTD are interesting drug design targets.
Numerous large-scale genomic studies of matched tumor-normal samples have established the somatic landscapes of most cancer types. However, the downstream analysis of data from somatic mutations ...entails a number of computational and statistical approaches, requiring usage of independent software and numerous tools. Here, we describe an R Bioconductor package, Maftools, which offers a multitude of analysis and visualization modules that are commonly used in cancer genomic studies, including driver gene identification, pathway, signature, enrichment, and association analyses. Maftools only requires somatic variants in Mutation Annotation Format (MAF) and is independent of larger alignment files. With the implementation of well-established statistical and computational methods, Maftools facilitates data-driven research and comparative analysis to discover novel results from publicly available data sets. In the present study, using three of the well-annotated cohorts from The Cancer Genome Atlas (TCGA), we describe the application of Maftools to reproduce known results. More importantly, we show that Maftools can also be used to uncover novel findings through integrative analysis.
Organic photodetectors (OPDs) have attracted continuous attention due to their outstanding advantages, such as tunability of detecting wavelength, low‐cost manufacturing, compatibility with ...lightweight and flexible devices, as well as ease of processing. Enormous efforts on performance improvement and application of OPDs have been devoted in the past decades. In this Review, recent advances in device architectures and operation mechanisms of phototransistor, photoconductor, and photodiode based OPDs are reviewed with a focus on the strategies aiming at performance improvement. The application of OPDs in spectrally selective detection, wearable devices, and integrated optoelectronics are also discussed. Furthermore, some future prospects on the research challenges and new opportunities of OPDs are covered.
Recent progress in organic photodetectors is reviewed, including different device structures, features, and operation mechanisms. Benefiting from the improved performance, the applications of organic photodetectors for selective detection, wearability, and integrated devices are highlighted.
Simultaneous transformation of CO2 and H2O into syngas (CO and H2) using solar power is desirable for industrial applications. Herein, an efficient photocatalyst based on double‐shelled nanoboxes, ...with an outer shell of hydroxy‐rich nickel cobaltite nanosheets and an inner shell of Cu2S (Cu2S@ROH‐NiCo2O3), is prepared via a multistep templating strategy. The high performance of Cu2S@ROH‐NiCo2O3 (7.1 mmol g−1 h−1 for CO; 2.8 mmol g−1 h−1 for H2) is attributed to the hierarchical hollow geometry and p–n heterojunction to promote light absorption and charge separation. Spectroscopic and theoretical analyses elucidate that the ROH‐NiCo2O3 surface enhances *CO2 adsorption and lowers energy barriers for CO2‐to‐CO. Therefore, modulating the hydroxy contents of ROH‐NiCo2O3 can achieve broad CO/H2 ratios from 0.51 to 1.24. This work offers in‐depth insights into adjustable syngas photosynthesis and generalized concepts of selective heterogeneous CO2 photoreduction beyond cobalt‐based oxides.
Hierarchical Cu2S@ROH‐NiCo2O3 double‐shelled nanoboxes are synthesized through a multistep strategy to regulate the activity and selectivity of CO2 photoreduction into syngas. The hierarchical hollow structure and p–n heterojunction enable enhanced light absorption and fast charge separation. Moreover, the catalytic activity can be tuned by controlling the content of hydroxy groups on the surfaces of ROH‐NiCo2O3.
Utilizing sunlight to convert CO2 into chemical fuels could simultaneously address the greenhouse effect and fossil fuel crisis. ZnSe nanocrystals are promising candidates for photocatalysis because ...of their low toxicity and excellent photoelectric properties. However, pristine ZnSe generally has low catalytic activities due to serious charge recombination and the lack of efficient catalytic sites for CO2 reduction. Herein, a ZnSe nanorods–CsSnCl3 perovskite (ZnSe–CsSnCl3) type II heterojunction composite is designed and prepared for photocatalytic CO2 reduction. The ZnSe–CsSnCl3 type II heterojunction composite exhibits enhanced photocatalytic activity for CO2 reduction with respect to pristine ZnSe nanorods. The experimental characterizations and theoretical calculations reveal that the efficient charge separation and lowered free energy of CO2 reduction facilitate the CO2 conversion on the ZnSe–CsSnCl3 heterojunction composite. This work presents a type II heterojunction composite photocatalyst based on ecofriendly metal chalcogenides and metal halide perovskites. Our study has also promoted the understanding of the CO2 reduction mechanisms on perovskite nanocrystals, which could be valuable for the development of metal halide perovskite photocatalysts.
Based on detailed in situ attenuated total‐reflection–surface‐enhanced IR reflection absorption spectroscopy (ATR‐SEIRAS) studies of the methanol oxidation reaction (MOR) on Ru/Pt thin film and ...commercial Johnson–Matthey PtRu/C, a revised MOR enhancement mechanism is proposed in which CO on Pt sites is irrelevant but instead Pt‐Ru boundary sites catalyze the oxygen insertion reaction that leads to the formation of formate and enhances the direct reaction pathway.
The methanol oxidation reaction (MOR) on Ru/Pt thin film and commercial PtRu/C was studied by in situ attenuated total‐reflection–surface‐enhanced IR reflection absorption spectroscopy. A revised MOR enhancement mechanism is proposed in which CO on Pt sites is irrelevant but instead Pt–Ru boundary sites catalyze the oxygen insertion reaction that leads to the formation of bidentate formate (indicated as OOCH) and enhances the direct reaction pathway.
1 These microbial communities reside with varied density in different segments of the gut and play a crucial role in many aspects of physiological processes, including facilitating food digestion and ...energy utilization, synthesizing vitamins and essential amino acids, promoting the development of the immune system, maintaining the integrity of the gut mucosal barrier, and protecting against enterogenous pathogens. Butyrate-producing anaerobes cannot directly utilize fructooligosaccharides and starch but can utilize lactate and acetate as growth substrates. ...B. adolescentis can facilitate the proliferation and expansion of butyrate-producing species in vivo by cross-feeding. Deconjugated bile acids can be further used by bacteria or reabsorbed by the liver for bile acid enterohepatic circulation. Short-chain fatty acids (SCFAs), produced by bacteria in the large intestine through fermentation of fibers, have broad effects on enterocytes, including maintenance of epithelial integrity, regulation of Treg differentiation and accumulation, and modulation of inflammatory and immune responses.
Ferroptosis is a recently recognized form of regulated cell death caused by an iron‐dependent accumulation of lipid reactive oxygen species. However, the molecular mechanisms regulating ferroptosis ...remain obscure. Here, we report that nuclear factor erythroid 2‐related factor 2 (NRF2) plays a central role in protecting hepatocellular carcinoma (HCC) cells against ferroptosis. Upon exposure to ferroptosis‐inducing compounds (e.g., erastin, sorafenib, and buthionine sulfoximine), p62 expression prevented NRF2 degradation and enhanced subsequent NRF2 nuclear accumulation through inactivation of Kelch‐like ECH‐associated protein 1. Additionally, nuclear NRF2 interacted with transcriptional coactivator small v‐maf avian musculoaponeurotic fibrosarcoma oncogene homolog proteins such as MafG and then activated transcription of quinone oxidoreductase‐1, heme oxygenase‐1, and ferritin heavy chain‐1. Knockdown of p62, quinone oxidoreductase‐1, heme oxygenase‐1, and ferritin heavy chain‐1 by RNA interference in HCC cells promoted ferroptosis in response to erastin and sorafenib. Furthermore, genetic or pharmacologic inhibition of NRF2 expression/activity in HCC cells increased the anticancer activity of erastin and sorafenib in vitro and in tumor xenograft models. Conclusion: These findings demonstrate novel molecular mechanisms and signaling pathways of ferroptosis; the status of NRF2 is a key factor that determines the therapeutic response to ferroptosis‐targeted therapies in HCC cells. (Hepatology 2016;63:173–184)
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