Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

Feasibility and Safety of Intracardiac Echocardiography Use in Transcatheter Left Atrial Appendage Closure Procedures

Background: Left atrial appendage closure (LAAC) is usually performed under the guidance of transesophageal echocardiography (TEE). Data on the safety of intracardiac echocardiogram (ICE)–guided LAAC from a real-world population in the United States remain limited. In this study, the aim was to evaluate the trends and outcomes of ICE-guided LAAC procedures using the US National Inpatient Sample. Methods: This study used the National Inpatient Sample database from quarter 4 of 2015 to 2019. We used a propensity-matched analysis and adjusted odds ratios for in-hospital outcomes/complications. A P value of \u3c .05 was considered significant. Results: We identified 61,995 weighted LAAC cases. Of these, 1410 patients had ICE-guided LAAC with a lower median age than the patients who had TEE-guided LAAC (75 vs 77 years; P ≤ .01). The use of ICE-guided LAAC increased from 1.7% in 2015 to 2.2% in 2019 (Ptrend = .75). Major, cardiovascular, neurologic, and pulmonary complications were similar for ICE-guided and TEE-guided LAAC on adjusted analysis. On propensity-matched analysis, the overall vascular complication rates were similar. However, retroperitoneal bleeding remained significantly higher (0.7% vs 0%) with ICE. Gastrointestinal bleeding complications were more frequent in TEE-guided LAAC (3.5% vs 2.1%). The length of stay was similar for both groups (median = 1 day; P = .23); however, ICE was associated with $1769 excess cost of hospitalization ($25,112 vs $23,343; P = .04). Conclusions: ICE–guided LAAC is safer than TEE-guided LAAC, with similar rates of major complications. However, ICE use was associated with lower rates of gastrointestinal bleeding and higher rates of retroperitoneal bleeding. In addition, ICE-guided LAAC is associated with a similar length of stay but higher costs of hospitalization

Age and geochemistry of the Newania dolomite carbonatites, India: implications for the source of primary carbonatite magma

The Newania carbonatite complex of India is one of the few dolomite-dominated carbonatites of the world. Intruding into Archean basement gneisses, the rocks of the complex have undergone limited diversification and are not associated with any alkaline silicate rock. Although the magmatic nature of the complex was generally accepted, its age of emplacement had remained equivocal because of the disturbed nature of radioisotope systems. Many questions about the nature of its mantle source and mode of origin had remained unanswered because of lack of geochemical and isotopic data. Here, we present results of our effort to date the complex using Sm-147-Nd-143, Pb-207-Pb-206 and Ar-40-Ar-39 dating techniques. We also present mineral chemistry, major and trace element geochemistry and Sr-Nd isotopic ratio data for these carbonatites. Our age data reveal that the complex was emplaced at similar to 1,473 Ma and parts of it were affected by a thermal event at similar to 904 Ma. The older Pb-207-Pb-206 ages reported here (similar to 2.4 Ga) and by one earlier study (similar to 2.3 Ga; Schleicher et al. Chem Geol 140:261-273, 1997) are deemed to be a result of heterogeneous incorporation of crustal Pb during the post-emplacement thermal event. The thermal event had little effect on many magmatic signatures of these rocks, such as its dolomite-magnesite-ankerite-Cr-rich magnetite-magnesio-arfvedsonite-pyrochlore assemblage, mantle like delta(13) C and delta O-18 and typical carbonatitic trace element patterns. Newania carbonatites show fractional crystallization trend from high-Mg to high-Fe through high-Ca compositions. The least fractionated dolomite carbonatites of the complex possess very high Mg# (>= 80) and have similar major element oxide contents as that of primary carbonatite melts experimentally produced from peridotitic sources. In addition, lower rare earth element (and higher Sr) contents than a typical calciocarbonatite and mantle like Nb/Ta ratios indicate that the primary magma for the complex was a magnesio-carbonatite melt and that it was derived from a carbonate bearing mantle. The Sr-Nd isotopic data suggest that the primary magma originated from a metasomatized lithospheric mantle. Trace element modelling confirms such an inference and suggests that the source was a phlogopite bearing mantle, located within the garnet stability zone

Dnmt2 functions in the cytoplasm to promote liver, brain, and retina development in zebrafish

The roles of DNA methyltransferase-2 (DNMT2) enzymes are controversial; whether DNMT2 functions primarily as a nuclear DNA methyltransferase or as a cytoplasmic tRNA methyltransferase, and whether DNMT2 activity impacts development, as dnmt2 mutant mice or Drosophila lack phenotypes. Here we show that morpholino knockdown of Dnmt2 protein in zebrafish embryos confers differentiation defects in particular organs, including the retina, liver, and brain. Importantly, proper organ differentiation required Dnmt2 activity in the cytoplasm, not in the nucleus. Furthermore, zebrafish Dnmt2 methylates an RNA species of ∼80 bases, consistent with tRNA methylation. Thus, Dnmt2 promotes zebrafish development, likely through cytoplasmic RNA methylation

Same-Day Discharge after Percutaneous Left Atrial Appendage Closure: Insights from the Nationwide Readmission Database 2015-2019

Data on the feasibility of same-day discharge (SDD) following percutaneous left atrial appendage closure (LAAC) remain limited. We analyzed the US Nationwide Readmission Database from quarter four of 2015 to 2019 to study the safety and feasibility of SDD after LAAC. After excluding non-elective cases and in-hospital deaths, a total of 54,880 cases of LAAC were performed during the study period. Following LAAC, 2% (n=1077) of patients underwent SDD, 88% (n=48,428) underwent next-day discharge (NDD), 5.2% (n=2881) were discharged on the second day (ScD), and 4.5% of patients (n = 2494) were discharged 3 or more days after LAAC. There was no difference in 30-day readmission rates between SDD and NDD (7.3% [n=79] vs 7.4% [n=3585], P=0.94). The hospitalization costs were significantly lower for SDD compared with NDD ($22,963 vs$27,079, P≤ 0.01). SDD discharge following percutaneous LAAC appears to be safe and is associated with lower hospitalization costs. Further prospective studies are needed to determine the safety and feasibility of SDD with percutaneous LAAC

Schematic representation showing genome organization of <i>ABCB1</i> gene and the analyzed regions for SNPs and CpG sites (indicated in blue).

<p>Exons are indicated as boxes.</p

Genotype/allele frequency data of SNPs of <i>ABCB1</i> gene and the results of the test for genetic association with case (uncomplicated, complicated and all malaria) and control, with measures of statistical significance.

<p>Genotype/allele frequency data of SNPs of <i>ABCB1</i> gene and the results of the test for genetic association with case (uncomplicated, complicated and all malaria) and control, with measures of statistical significance.</p