On quasi-Jacobi and Jacobi-quasi bialgebroids

We study quasi-Jacobi and Jacobi-quasi bialgebroids and their relationships with twisted Jacobi and quasi Jacobi manifolds. We show that we can construct quasi-Lie bialgebroids from quasi-Jacobi bialgebroids, and conversely, and also that the structures induced on their base manifolds are related via a quasi Poissonization

Jacobi-Nijenhuis algebroids and their modular classes

Jacobi-Nijenhuis algebroids are defined as a natural generalization of Poisson-Nijenhuis algebroids, in the case where there exists a Nijenhuis operator on a Jacobi algebroid which is compatible with it. We study modular classes of Jacobi and Jacobi-Nijenhuis algebroids

Risk Factors for Bleeding After Gastric Endoscopic Submucosal Dissection: a Systematic Review and Meta-Analysis

BACKGROUND AND AIMS: Postprocedural bleeding (PPB) is the most common adverse event associated with endoscopic resection. Several studies have tried to identify risk factors for PPB after gastric EMR and endoscopic submucosal dissection (ESD), with controversial results. This systematic review and meta-analysis aimed to identify significant risk factors for PPB after gastric EMR and ESD. METHODS: Three online databases were searched. Pooled odds ratio (OR) was computed for each risk factor using a random-effects model, and heterogeneity was assessed by Cochran's Q test and I(2). RESULTS: Seventy-four articles were included. Pooled PPB rate was 5.1% (95% confidence interval, 4.5%-5.7%), which did not vary according to different study designs. Male sex (OR, 1.25), cardiopathy (OR, 1.54), antithrombotic drugs (OR, 1.63), cirrhosis (OR, 1.76), chronic kidney disease (OR, 3.38), tumor size > 20 mm (OR, 2.70), resected specimen size > 30 mm (OR, 2.85), localization in the lesser curvature (OR, 1.74), flat/depressed morphology (OR, 1.43), carcinoma histology (OR, 1.46), and ulceration (OR, 1.64) were identified as significant risk factors for PPB, whereas age, hypertension, submucosal invasion, fibrosis, and localization (upper, middle, or lower third) were not. Procedure duration > 60 minutes (OR, 2.05) and the use of histamine-2 receptor antagonists instead of proton pump inhibitors (OR, 2.13) were the procedural factors associated with PPB, whereas endoscopist experience and preprocedural proton pump inhibitors were not. Second-look endoscopy was not associated with decreased PPB (OR, 1.34; 95% confidence interval, .85-2.12). CONCLUSIONS: Risk factors for PPB were identified that can help to guide management after gastric ESD, namely adjusting further management. Second-look endoscopy is not associated with decreased PPB.info:eu-repo/semantics/publishedVersio

Molecular fingerprints for a novel enzyme family in actinobacteria with glucosamine kinase activity

Actinobacteria have long been the main source of antibiotics, secondary metabolites with tightly controlled biosynthesis by environmental and physiological factors. Phosphorylation of exogenous glucosamine has been suggested as a mechanism for incorporation of this extracellular material into secondary metabolite biosynthesis, but experimental evidence of specific glucosamine kinases in Actinobacteria is lacking. Here, we present the molecular fingerprints for the identification of a unique family of actinobacterial glucosamine kinases. Structural and biochemical studies on a distinctive kinase from the soil bacterium Streptacidiphilus jiangxiensis unveiled its preference for glucosamine and provided structural evidence of a phosphoryl transfer to this substrate. Conservation of glucosamine-contacting residues across a large number of uncharacterized actinobacterial proteins unveiled a specific glucosamine binding sequence motif. This family of kinases and their genetic context may represent the missing link for the incorporation of environmental glucosamine into the antibiotic biosynthesis pathways in Actinobacteria and can be explored to enhance antibiotic production. IMPORTANCE The discovery of novel enzymes involved in antibiotic biosynthesis pathways is currently a topic of utmost importance. The high levels of antibiotic resistance detected worldwide threaten our ability to combat infections and other 20th-century medical achievements, namely, organ transplantation or cancer chemotherapy. We have identified and characterized a unique family of enzymes capable of phosphorylating glucosamine to glucosamine-6-phosphate, a crucial molecule directly involved in the activation of antibiotic production pathways in Actinobacteria, nature’s main source of antimicrobials. The consensus sequence identified for these glucosamine kinases will help establish a molecular fingerprint to reveal yet-uncharacterized sequences in antibiotic producers, which should have an important impact in biotechnological and biomedical applications, including the enhancement and optimization of antibiotic production.We acknowledge the European Synchrotron Radiation Facility (Grenoble, France) for provision of synchrotron radiation facilities and thank their staff for help with data collection. Part of these experiments were performed at beamline BL13-XALOC of ALBA Synchrotron (Cerdanyola del Vallès, Spain), with the collaboration of ALBA staff and CALIPSOplus (grant 730872) funding. The support of the X-ray Crystallography Scientific Platform of i3S (Porto, Portugal) is also acknowledged. We thank Pedro Lamosa from CERMAX, ITQB-NOVA (Oeiras, Portugal), for acquiring and interpreting the NMR data. This work was supported by the Structured Program on Bioengineered Therapies for Infectious Diseases and Tissue Regeneration (Norte-01-0145-FEDER-‏000‏012), funded by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through Fundo Europeu de Desenvolvimento Regional (FEDER) and by FEDER through the COMPETE 2020-Operational Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT-Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of project Institute for Research and Innovation in Health Sciences (POCI-01-0145-FEDER-007274) and also by grants UID/NEU/04539/2019 and POCI-01-0145-FEDER-029221. D.N.-C. acknowledges the European Regional Development Fund (CENTRO-01-0145-FEDER-000012-ealthyAging2020) for a research fellowship and FCT for Ph‏D f‏ellowship SFRH/BD/117777/2016

Intrachromosomal excision of a hybrid Ds element induces large genomic deletions in Arabidopsis

Transposon activity is known to cause chromosome rearrangements in the host genome. Surprisingly, extremely little is known about Dissociation (Ds)-induced chromosome rearrangements in Arabidopsis, where Ds is intensively used for insertional mutagenesis. Here, we describe three Arabidopsis mutants with reduced fertility and propose that excision of a hybrid Ds element induced a large genomic deletion flanking Ds. In the mutants anat and haumea, the deletion mechanism consists of a local Ds transposition from replicated into unreplicated DNA followed by Ds excision, where one end of the newly transposed element and one end of the Ds transposon at the donor site served as substrate for transposase. Excision of this hybrid element reminiscent of a macrotransposon leads to loss of the chromosomal piece located between the two ends, including one full Ds element and the flanking genomic sequence. This mechanism was found to be responsible for several other deletions and occurs at a genetically trackable frequency. Thus, it could be applied to efficiently generate deletions of various sizes in the vicinity of any existing Ds element present in the genome. In the mutant tons missing, a mechanism that involves endogenous repetitive sequences caused a large flanking deletion at a position unlinked to the starter locus. Our study of Ds transposition in Arabidopsis revealed previously undescribed mechanisms that lead to large genomic deletions flanking Ds elements, which may contribute to genome dynamics and evolution

Divergência genética entre cultivares de cebola com base em descritores agromorfológicos.

Suplemento. Edição dos Trabalhos do 50. Congresso Brasileiro de Olericultura, Guarapari, jul. 2010