Production and Digestibility Studies of ß-Galactosyl Xylitol Derivatives Using Heterogeneous Catalysts of LacA ß-Galactosidase from Lactobacillus Plantarum WCFS1.

The synthesis of ß-galactosyl xylitol derivatives using immobilized LacA ß-galactosidase from Lactobacillus plantarum WCFS1 is presented. These compounds have the potential to replace traditional sugars by their properties as sweetener and taking the advantages of a low digestibility. The enzyme was immobilized on different supports, obtaining immobilized preparations with different activity and stability. The immobilization on agarose-IDA-Zn-CHO in the presence of galactose allowed for the conserving of 78% of the offered activity. This preparation was 3.8 times more stable than soluble. Since the enzyme has polyhistidine tags, this support allowed the immobilization, purification and stabilization in one step. The immobilized preparation was used in synthesis obtaining two main products and a total of around 68 g/L of ß-galactosyl xylitol derivatives and improving the synthesis/hydrolysis ratio by around 30% compared to that of the soluble enzyme. The catalyst was recycled 10 times, preserving an activity higher than 50%. The in vitro intestinal digestibility of the main ß-galactosyl xylitol derivatives was lower than that of lactose, being around 6 and 15% for the galacto-xylitol derivatives compared to 55% of lactose after 120 min of digestion. The optimal amount immobilized constitutes a very useful tool to synthetize ß-galactosyl xylitol derivatives since it can be used as a catalyst with high yield and being recycled for at least 10 more cycles.

Using Machine Learning to Collect and Facilitate Remote Access to Biomedical Databases: Development of the Biomedical Database Inventory.

BACKGROUND: Currently, existing biomedical literature repositories do not commonly provide users with specific means to locate and remotely access biomedical databases. OBJECTIVE: To address this issue, we developed the Biomedical Database Inventory (BiDI), a repository linking to biomedical databases automatically extracted from the scientific literature. BiDI provides an index of data resources and a path to access them seamlessly. METHODS: We designed an ensemble of deep learning methods to extract database mentions. To train the system, we annotated a set of 1242 articles that included mentions of database publications. Such a data set was used along with transfer learning techniques to train an ensemble of deep learning natural language processing models targeted at database publication detection. RESULTS: The system obtained an F1 score of 0.929 on database detection, showing high precision and recall values. When applying this model to the PubMed and PubMed Central databases, we identified over 10,000 unique databases. The ensemble model also extracted the weblinks to the reported databases and discarded irrelevant links. For the extraction of weblinks, the model achieved a cross-validated F1 score of 0.908. We show two use cases: one related to "omics" and the other related to the COVID-19 pandemic. CONCLUSIONS: BiDI enables access to biomedical resources over the internet and facilitates data-driven research and other scientific initiatives. The repository is openly available online and will be regularly updated with an automatic text processing pipeline. The approach can be reused to create repositories of different types (ie, biomedical and others).

Biology of SARS-CoV-2: Towards understanding and treating COVID-19. / Biología del SARS-CoV-2: hacia el entendimiento y tratamiento de COVID-19.

During the last two decades, three different epidemics, caused by three different coronaviruses, have affected humankind. The most recent, known as COVID-19, has caused in only five months, more than 340,000 deaths worldwide. Knowing the biology of coronavirus is key, not just to face the current pandemic, but to prepare ourselves for future epidemics. With this in mind, this article is focused on the biology of coronaviruses emphasizing SARS-CoV-2, the agent that causes COVID-19. This is a comprehensive review article, which covers different topics, from the biology and taxonomy of viruses, to the molecular biology of SARS-CoV-2, its mechanisms of action, and the immune response this virus elicits. We have also addressed clinical aspects of COVID-19, its methods of detection, treatment, and vaccines.

Durante las últimas dos décadas, tres epidemias de gran magnitud, causadas por tres distintos tipos de coronavirus, han impactado a la humanidad. La más reciente, conocida como COVID-19, ha provocado en tan solo cinco meses, más de 340 000 muertes en todo el mundo. Conocer la biología de los coronavirus es fundamental, tanto para enfrentar la pandemia actual, como para prepararnos para futuras epidemias. En este contexto, el presente artículo está enfocado en la biología de los coronavirus con énfasis en el SARS-CoV-2, agente causal de COVID-19. La temática que se incluye es muy amplia, abarca desde la biología general de los virus y su taxonomía, hasta aspectos muy puntuales de la biología molecular de SARS-CoV-2, así como de sus mecanismos de acción y la respuesta inmune. También presentamos distintos aspectos clínicos de COVID-19, de los métodos para su detección y algunos enfoques terapéuticos, incluyendo tratamientos antivirales y vacunas.