3,456 research outputs found
Study of the Potential Accumulation of the Pesticide Alpha-Endosulfan by Microplastics in Water Systems
Microplastics (MP) are spread into all ecosystems and represent a threat to the equilibrium of the environment and human health, not only due to their intrinsic characteristics but also to their action as effective carriers of contaminants, such as pesticides, pharmaceuticals, polychlorinated biphenyls and polycyclic aromatic hydrocarbons. The pesticide α-endosulfan is persistent and spread in the environment. The MP are another possible way of dissemination to be considered in the fate of this pesticide. The adsorption dynamics of α-endosulfan by six different MP (low-density polyethylene—LDPE, polyethylene-co-vinyl acetate, unplasticized polyvinyl chloride, polyamide 6, polystyrene granule, polypropylene granule) with different sizes/shapes and chemical compositions were evaluated. The most critical situation was identified for the system LDPE (particle size < 300 μm). Equilibrium studies (48 h equilibrium time) were performed for distilled, tap and filtered river water. Based on the Langmuir model parameters, the highest maximum adsorption capacity was obtained for distilled water, followed by filtered river and tap waters (i.e., 366 ± 39, 247 ± 38, 157 ± 22 μg/g). The obtained results demonstrate the important role that microplastics may have in the fate and transport of pesticides and their potentially harmful effect on the environment, which requires further investigationThis research was funded by the Associate Laboratory for Green Chemistry-LAQV, which received financial support from UIDB/50006/2020, UIDP/50006/2020, and LA/P/0008/2020 by the Fundação para a Ciência e a Tecnologia (FCT)/Ministério da Ciência, Tecnologia e Ensino Superior (MCTES) through national funds. This research was funded through the 2019–2020 Biodiversa & Water JPI joint call for research proposals, under the BiodivRestore ERA-Net COFUND programme, DivRestore/0002/2020, and with the funding organisation FCT, Portugal. Virgínia Cruz Fernandes thanks FCT for the financial support through a postdoctoral fellowship (SFRH/BPD/109153/2015). Also, Sílvia Daniela Martinho thanks FCT for the financial support through a doctoral fellowship (SFRH/BD/13595/2022). The authors are greatly indebted to all financing sources.info:eu-repo/semantics/publishedVersio
Microplastic Pollution Focused on Sources, Distribution, Contaminant Interactions, Analytical Methods, and Wastewater Removal Strategies: A Review
Plastics have been one of the most useful materials in the world, due to their distinguishing characteristics: light weight, strength, flexibility, and good durability. In recent years, the growing consumption of plastics in industries and domestic applications has revealed a serious problem in plastic waste treatments. Pollution by microplastics has been recognized as a serious threat since it may contaminate all ecosystems, including oceans, terrestrial compartments, and the atmosphere. This micropollutant is spread in all types of environments and is serving as a “minor but efficient” vector for carrier contaminants such as pesticides, pharmaceuticals, metals, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The need to deeply study and update the evolution of microplastic sources, toxicology, extraction and analysis, and behavior is imperative. This review presents an actual state of microplastics, addressing their presence in the environment, the toxicological effects and the need to understand their extent, their interactions with toxic pollutants, the problems that arise in the definition of analytical methods, and the possible alternatives of treatmentsThis research was funded by the Associate Laboratory for Green Chemistry-LAQV, which
received financial support from UIDB/50006/2020, UIDP/50006/2020, and LA/P/0008/2020 by
the Fundação para a Ciência e a Tecnologia (FCT)/Ministério da Ciência, Tecnologia e Ensino
Superior (MCTES) through national funds. The research was funded also by FCT and BiodivRestore
Joint Call 2020–2021—European Union’s Horizon 2020 research and innovation programme under
grant agreement No 101003777-BiodivRestore-406/DivRestore/0002/2020-BioReset-“Biodiversity
restoration and conservation of inland water ecosystems for environmental and human well-being”.
Virgínia Cruz Fernandes thanks FCT for the financial support through a postdoctoral fellowship
(SFRH/BPD/109153/2015). The authors are greatly indebted to all financing sourcesinfo:eu-repo/semantics/publishedVersio
Contribuições da Coordenação de Empreendedorismo e Desenvolvimento Empresarial e Social do Centro de Apoio ao Desenvolvimento Tecnológico da UnB para as Diretrizes Estratégicas da Política de Inovação Institucional
The Innovation Law defined the concept of innovation in Brazil and guided the creation of Technological Innovation Centers (NIT) in science and technology institutions (ICTs) to, among other tasks, encourage entrepreneurship and innovation. The article deals with a case study of the contributions of the Entrepreneurship and Business and Social Development Coordination (CEDES) of the UnB Technological Development Support Center (CDT), which acts as its technological innovation nucleus (NIT) for the implementation of the strategic guidelines of institutional innovation policy (PI/UnB), through field research and extensive documental investigation and bibliographic research. The results of indicators related to impact entrepreneurship and innovation in the period from 2017 to 2021 proved the fundamental role of CEDES for the implementation of the corresponding strategic guidelines listed in the innovation policy of the University of Brasília, despite the negative impacts caused by the SARS-COV-2 pandemic.A Lei da Inovação definiu o conceito de inovação no Brasil e pautou a criação dos Núcleos de Inovação Tecnológicas (NIT) nas Instituições de Ciência e Tecnologia (ICTs) para, entre outras atribuições, incentivar o empreendedorismo e a inovação. O artigo fez um estudo de caso das contribuições da Coordenação de Empreendedorismo e Desenvolvimento Empresarial e Social (CEDES) do Centro de Apoio ao Desenvolvimento Tecnológico da UnB (CDT), que atua como seu Núcleo de Inovação Tecnológica (NIT) para a implementação das diretrizes estratégicas da Política de Inovação institucional (PI/UnB), por meio de uma pesquisa de campo e uma ampla investigação documental e de pesquisa bibliográfica. Os resultados dos indicadores relacionados ao empreendedorismo de impacto e inovação no período de 2017 a 2021 comprovaram o papel fundamental da CEDES para a implementação das diretrizes estratégicas correspondentes elencadas na política de inovação da Universidade de Brasília, apesar dos impactos negativos causados pela pandemia de SARS-COV-2
Biofilm Formation by Listeria monocytogenes 15G01, a Persistent Isolate from a Seafood-Processing Plant, Is Influenced by Inactivation of Multiple Genes Belonging to Different Functional Groups
Listeria monocytogenes is a ubiquitous foodborne pathogen that results in a high rate of mortality in sensitive and immunocompromised people. Contamination of food with L. monocytogenes is thought to occur during food processing, most often as a result of the pathogen producing a biofilm that persists in the environment and acting as the source for subsequent dispersal of cells onto food. A survey of seafoodprocessing plants in New Zealand identified the persistent strain 15G01, which has a high capacity to form biofilms. In this study, a transposon library of L. monocytogenes 15G01 was screened for mutants with altered biofilm formation, assessed by a crystal violet assay, to identify genes involved in biofilm formation. This screen identified 36 transposants that showed a significant change in biofilm formation compared to the wild type. The insertion sites were in 27 genes, 20 of which led to decreased biofilm formation and seven to an increase. Two insertions were in intergenic regions. Annotation of the genes suggested that they are involved in diverse cellular processes, including stress response, autolysis, transporter systems, and cell wall/membrane synthesis. Analysis of the biofilms produced by the transposants using scanning electron microscopy and fluorescence microscopy showed notable differences in the structure of the biofilms compared to the wild type. In particular, inactivation of uvrB and mltD produced coccoid-shaped cells and elongated cells in long chains, respectively, and the mgtB mutant produced a unique biofilm with a sandwich structure which was reversed to the wild-type level upon magnesium addition. The mltD transposant was successfully complemented with the wild-type gene, whereas the phenotypes were not or only partially restored for the remaining mutants. IMPORTANCE The major source of contamination of food with Listeria monocytogenes is thought to be due to biofilm formation and/or persistence in food-processing plants. By establishing as a biofilm, L. monocytogenes cells become harder to eradicate due to their increased resistance to environmental threats. Understanding the genes involved in biofilm formation and their influence on biofilm structure will help identify new ways to eliminate harmful biofilms in food processing environments. To date, multiple genes have been identified as being involved in biofilm formation by L. monocytogenes; however, the exact mechanism remains unclear. This study identified four genes associated with biofilm formation by a persistent strain. Extensive microscopic analysis illustrated the effect of the disruption of mgtB, clsA, uvrB, and mltD and the influence of magnesium on the biofilm structure. The results strongly suggest an involvement in biofilm formation for the four genes and provide a basis for further studies to analyze gene regulation to assess the specific role of these biofilm-associated genes.Peer reviewe
Screening for new natural food additives with antibacterial properties against pathogenic bacteria : [poster]
• Due to increasing customer awareness, there is a trend to
seek new natural food additives that can be used as antibacterial
and/or antioxidative agents in food products [1]
• Plant-based extracts consist of compounds that can possess
antibacterial properties and may extend the shelf-life and enhance
food safety [2]
Aim: Find potential natural antimicrobials for food industry by testing
antimicrobial properties of plant extracts against
pathogenic bacteria.Poster of the Nordic Natural Products Conference 2023.This work was supported by the Estonian Research Council grant PRG 1441.This work was supported by the Estonian Research Council grant PRG 1441
Installation of an aryl boronic acid function into the external section of N-aryl-oxazolidinones : Synthesis and antimicrobial evaluation
N-aryl-oxazolidinones is a prominent family of antimicrobials used for treating infections caused by clinically prevalent Gram-positive bacteria. Recently, boron-containing compounds have displayed intriguing potential in the antibiotic discovery setting. Herein, we report the unprecedented introduction of a boron-containing moiety such as an aryl boronic acid in the external region of the oxazolidinone structure via a chemoselective acyl coupling reaction. As a result, we accessed a series of analogues with a distal aryl boronic pharmacophore on the oxazolidinone scaffold. We identified that a peripheric linear conformation coupled with freedom of rotation and no further substitution on the external aryl boronic ring, an amido linkage with hydrogen bonding character, in addition to a para-relative disposition between boronic group and linker, are the optimal combination of structural features in this series for antimicrobial activity. In comparison to linezolid, the analogue comprising all those features, compound 20b, displayed levels of antimicrobial activity augmented by an eight-fold to a thirty-two-fold against a panel of Gram-positive strains, and a near one hundred-fold against Escherichia coli JW5503, a Gram-negative mutant strain with a defective efflux capability.Peer reviewe
Design, synthesis and biological evaluation of novel DNA gyrase Inhibitors and their siderophore mimic conjugates
Bacterial DNA gyrase is an important target for the development of novel antibacterial drugs, which are urgently needed because of high level of antibiotic resistance worldwide. We designed and synthesized new 4,5,6,7-tetrahydrobenzo[d]thiazole-based DNA gyrase B inhibitors and their conjugates with siderophore mimics, which were introduced to increase the uptake of inhibitors into the bacterial cytoplasm. The most potent conjugate 34 had an IC50 of 58 nM against Escherichia coli DNA gyrase and displayed MIC of 14 mu g/mL against E. coli.tolC strain. Only minor improvements in the antibacterial activities against wild-type E. coli in low-iron conditions were seen for DNA gyrase inhibitor - siderophore mimic conjugates.Peer reviewe
Multiple myeloma primary cells show a highly rearranged unbalanced genome with amplifications and homozygous deletions irrespective of the presence of immunoglobulin-related chromosome translocations
Background and Objectives
Multiple myeloma (MM) is a malignant plasma cell neoplasia in which genetic studies
have shown that genomic changes may affect almost all chromosomes, as shown
by fluorescence in situ hybridization (FISH) and comparative genomic hybridization
(CGH). Our objective was the genomic characterization of CD 138 positive primary MM
samples by means of a high resolution array CGH platform.
Design and Methods
For the first time, a high resolution array CGH with more than 40,000 probes, has
been used to analyze 26 primary MM samples after the enrichment of CD138-positive
plasma cells.
Results
This approach identified copy number imbalances in all cases. Bioinformatics strategies
were optimized to perform data analysis allowing the segregation of hyperdiploid
and non-hyperdiploid cases by array CGH. Additional analysis showed that structural
chromosome rearrangements were more frequently seen in hyperdiploid cases. We
also identified the same Xq21 duplication in nearly 20% of the cases, which originated
through unbalanced chromosome translocations. High level amplifications and
homozygous deletions were recurrently observed in our series and involved genes
with meaningful function in cancer biology.
Interpretation and Conclusions
High resolution array CGH allowed us to identify copy number changes in 100% of the
primary MM samples. We segregated different MM subgroups based on their genomic
profiles which made it possible to identify homozygous deletions and amplifications
of great genetic relevance in MM
Antibiotic Resistance among <i>Escherichia coli</i>: Isolates and Novel Approaches to the Control of <i>E. coli</i> Infections
Bacteria are the microorganisms that most frequently cause infectious diseases in humans. The synthesis of silver nanoparticles (AgNPs) has attracted interest due to the new and different physical and chemical characteristics with applications in new fields. AgNPs, alone or supported on ceramic, are used as antimicrobial fillers in textiles and polymers for food-packaging and biomedical applications, for antimicrobial paints, and potentially for drug delivery. The evaluation of mesoporous nanostructures or nanocomposites as FDU-12/lignin/silver was effective in inhibiting Staphylococcus aureus, E. coli, Enterococcus faecalis, and Candida albicans. The best results were achieved against the inhibition of E. coli and with the structures FDU-12/silver. In plates with FDU-12/lignin/silver, FDU-12, FDU-12/lignin, and the positive control, it was enumerated at 0, 6, 14, and 27 colonies, respectively. While the development of resistance to a new antibiotic is expected, the time course and degree of resistance are uncertain and depend on various factors. The application of AgNPs as nanocomposites can alter the expression of bacterial proteins and could be used for inactivation. This review explores such aspects and a number of factors arising like the use of nanostructures against E. coli, from the knowledge acquired
“Publishing Is Mystical”: The Latinx Caucus Bibliography, Top-Tier Journals, and Minority Scholarship
In 2014, members of the NCTE/CCCC Latinx Caucus began contributing citations to a shared Google Document (GDoc) that suggested a relatively significant contribution of scholarship to the field of Rhetoric and Composition studies. Scholars of color have argued that rhetoric and composition scholarship fails to represent diversity in academic publications (Baca; Banks; Jones Royster; Pimentel; Ruíz). This study examines statistical data arrived at through analysis of the NCTE/CCCC Latinx Caucus Bibliography, with survey and interview data from Latinx scholars providing important context about publishing for people of color
- …