Controlled synthesis of polycarbonate diols and their polylactide block copolymers using amino-bis(phenolate) chromium hydroxide complexes.

A diamine-bis(phenolate) chromium(III) complex, CrOH[L] ([L] = dimethylaminoethylamino-,-bis(2-methylene-4,6--butylphenolate)), 2, in the presence of tetrabutylammonium hydroxide effectively copolymerizes CO and cyclohexene oxide (CHO) into a polycarbonate diol. The resultant low molar mass (6.3 kg mol) diol is used to initiate ring-opening polymerization of -lactide with 1,8-diazabicyclo[5.

Identification of priority areas for water conservation in the Alto Iguaçu basin, Brazil.

Geoprocessing tools are great allies in the management of water resources, permitting the evaluation of several factors integrated into a multicriteria analysis. This improves the interpretation of the behavior of water and soil in hydrographic basins, allowing the delimitation of priority areas for actions. The objective of this study was to prepare a map of priority areas for water conservation in the Alto Iguaçu basin through a multicriteria analysis, aiming to assist in the management of water resources in the region.

Evolutionary conservation of an ancient retroviral gene in Artiodactyla.

The genomes of mammals contain fingerprints of past infections by ancient retroviruses that invaded the germline of their ancestors. Most of these endogenous retroviruses (ERVs) contain only remnants of the original retrovirus; however, on rare occasions, ERV genes can be co-opted for a beneficial host function. While most studies of co-opted ERVs have focused on envelope genes, including the syncytins that function in placentation, there are examples of co-opted genes including one we recently discovered in simian primates.

20-Month monitoring of SARS-CoV-2 in wastewater of Curitiba, in Southern Brazil.

The COVID-19 pandemic resulted in the collapse of healthcare systems and led to the development and application of several approaches of wastewater-based epidemiology to monitor infected populations. The main objective of this study was to carry out a SARS-CoV-2 wastewater based surveillance in Curitiba, Southern Brazil Sewage samples were collected weekly for 20 months at the entrance of five treatment plants representing the entire city and quantified by qPCR using the N1 marker. The viral loads were correlated with epidemiological data.

Planar bismuth triamides: a tunable platform for main group Lewis acidity and polymerization catalysis.

Geometric deformation in main group compounds can be used to elicit unique properties including strong Lewis acidity. Here we report on a family of bismuth(iii) complexes ( typically pyramidal structure for such compounds), which show a geometric Lewis acidity that can be further tuned by varying the steric and electronic features of the triamide ligand employed. The structural dynamism of the planar bismuth complexes was probed in both the solid and solution phase, revealing at least three distinct modes of intermolecular association.

Cross-species transmission of an ancient endogenous retrovirus and convergent co-option of its envelope gene in two mammalian orders.

Endogenous retroviruses (ERVs) found in vertebrate genomes are remnants of retroviral invasions of their ancestral species. ERVs thus represent molecular fossil records of ancient retroviruses and provide a unique opportunity to study viral-host interactions, including cross-species transmissions, in deep time. While most ERVs contain the mutated remains of the original retrovirus, on rare occasions evolutionary selection pressures lead to the co-option/exaptation of ERV genes for a host function.

Retroviral Elements in Pathophysiology and as Therapeutic Targets for Amyotrophic Lateral Sclerosis.

The study of the role of retroviruses in amyotrophic lateral sclerosis (ALS) dates back to the 1960s shortly after transposable elements themselves were first discovered. It was quickly realized that in wild mice both horizontal and vertical transmissions of retroviral elements were key to the development of an ALS-like syndrome leading to the postulate that endogenous retroviruses (ERVs) contribute significantly to the pathogenicity of this disease. Subsequent studies identified retroviral reverse transcriptase activity in brains of individuals with ALS from Guam.

Mechanosensitive Ion Channels, Axonal Growth, and Regeneration.

Cells sense and respond to mechanical stimuli by converting those stimuli into biological signals, a process known as mechanotransduction. Mechanotransduction is essential in diverse cellular functions, including tissue development, touch sensitivity, pain, and neuronal pathfinding. In the search for key players of mechanotransduction, several families of ion channels were identified as being mechanosensitive and were demonstrated to be activated directly by mechanical forces in both the membrane bilayer and the cytoskeleton.

Patterns of Coevolutionary Adaptations across Time and Space in Mouse Gammaretroviruses and Three Restrictive Host Factors.

The classical laboratory mouse strains are genetic mosaics of three subspecies that occupy distinct regions of Eurasia. These strains and subspecies carry infectious and endogenous mouse leukemia viruses (MLVs) that can be pathogenic and mutagenic. MLVs evolved in concert with restrictive host factors with some under positive selection, including the XPR1 receptor for xenotropic/polytropic MLVs (X/P-MLVs) and the post-entry restriction factor .

The Oldest Co-opted gag Gene of a Human Endogenous Retrovirus Shows Placenta-Specific Expression and Is Upregulated in Diffuse Large B-Cell Lymphomas.

Vertebrate genomes contain endogenous retroviruses (ERVs) that represent remnants of past germline infections by ancient retroviruses. Despite comprising 8% of the human genome, the human ERVs (HERVs) do not encode a replication competent retrovirus. However, some HERV genes have been co-opted to serve host functions, most notably the viral envelope-derived syncytins involved in placentation.

A novel class III endogenous retrovirus with a class I envelope gene in African frogs with an intact genome and developmentally regulated transcripts in Xenopus tropicalis.

Background: Retroviruses exist as exogenous infectious agents and as endogenous retroviruses (ERVs) integrated into host chromosomes. Such endogenous retroviruses (ERVs) are grouped into three classes roughly corresponding to the seven genera of infectious retroviruses: class I (gamma-, epsilonretroviruses), class II (alpha-, beta-, delta-, lentiretroviruses) and class III (spumaretroviruses). Some ERVs have counterparts among the known infectious retroviruses, while others represent paleovirological relics of extinct or undiscovered retroviruses.

Adaptive monitoring approach to assess dissolved organic matter dynamics during rainfall events.

Rainfall events induce water quality transformation in river systems influenced by the watershed land use and hydrology dynamics. In this context, an adaptive monitoring approach (AMA) is used to assess non-point sources (NPS) of pollution events, through dissolved organic matter (DOM) contribution. The case study is a monitoring site in a semi-urban watershed characterized by NPS contribution.

Retroviral Restriction Factors and Their Viral Targets: Restriction Strategies and Evolutionary Adaptations.

The evolutionary conflict between retroviruses and their vertebrate hosts over millions of years has led to the emergence of cellular innate immune proteins termed restriction factors as well as their viral antagonists. Evidence accumulated in the last two decades has substantially increased our understanding of the elaborate mechanisms utilized by these restriction factors to inhibit retroviral replication, mechanisms that either directly block viral proteins or interfere with the cellular pathways hijacked by the viruses. Analyses of these complex interactions describe patterns of accelerated evolution for these restriction factors as well as the acquisition and evolution of their virus-encoded antagonists.

Chromium Diamino-bis(phenolate) Complexes as Catalysts for the Ring-Opening Copolymerization of Cyclohexene Oxide and Carbon Dioxide.

Chromium diamino-bis(phenolate) complexes, CrX [where = 6,6'-((1,4-diazepane-1,4-diyl)bis(methylene))bis(2,4-dimethylphenolato) and X = Cl (), OH (), and N ()], were prepared and characterized by MALDI-TOF MS and single-crystal X-ray diffraction. Complex crystallized as two linkage isomers, specifically a green chloride-bridged dimer () and a pink asymmetrically bridged isomer exhibiting one chloride bridging atom and one bridging phenolate oxygen (). Adventitious moisture during sample handling causes the formation of hydroxide-containing complex .

Synthesis of a Renewable, Waste-Derived Nonisocyanate Polyurethane from Fish Processing Discards and Cashew Nutshell-Derived Amines.

Waste-derived fish oil (FO) can be epoxidized and reacted with CO to produce a cyclic carbonate containing material. Upon reaction with a bioderived amine, this leads to the formation of nonisocyanate polyurethane materials. The FO used is extracted from the by-products produced at fish processing plants, including heads, bones, skin, and viscera.

Applicability of conventional and non-conventional parameters for municipal landfill leachate characterization.

The disposal of municipal solid waste (MSW) in landfills generates leachate, a highly polluting liquid to the aquatic environment. Leachate composition become a challenge to choose the best treatment process. Then, detailed techniques to determine the organic content, in terms of refractability, composition, sources and biodegradability in landfill leachate can help to choose the appropriate treatment and improve landfill management.

Lithium, sodium, potassium and calcium amine-bis(phenolate) complexes in the ring-opening polymerization of rac-lactide.

Compounds of Li, Na, K and Ca of a tetradentate amino-bis(phenolato) ligand were prepared. Bimetallic compounds formulated as M[L](THF) (where M = Na, n = 1 (1·THF) or Li, n = 1 (2·THF)) were synthesized via the reaction of H[L] (where [L] = 2-pyridylmethylamino-N,N-bis(2-methylene-4-methoxy-6-tert-butylphenolato) with sodium hydride or n-butyllithium, respectively, in THF. Monometallic complexes MH[L](THF) (where M = Na, n = 1 (3·THF), Li, n = 0 (4) and K, n = 0 (5)) were obtained by reaction of H[L] with MN(SiMe) where M = Na, Li, or K.

Disrupting MLV integrase:BET protein interaction biases integration into quiescent chromatin and delays but does not eliminate tumor activation in a MYC/Runx2 mouse model.

Murine leukemia virus (MLV) integrase (IN) lacking the C-terminal tail peptide (TP) loses its interaction with the host bromodomain and extraterminal (BET) proteins and displays decreased integration at promoter/enhancers and transcriptional start sites/CpG islands. MLV lacking the IN TP via an altered open reading frame was used to infect tumorigenesis mouse model (MYC/Runx2) animals to observe integration patterns and phenotypic effects, but viral passage resulted in the restoration of the IN TP through small deletions. Mice subsequently infected with an MLV IN lacking the TP coding sequence (TP-) showed an improved median survival by 15 days compared to wild type (WT) MLV infection.

Bimetallic and trimetallic zinc amino-bis(phenolate) complexes for ring-opening polymerization of rac-lactide.

The synthesis and structural characterization of bimetallic and trimetallic zinc complexes of amino-bis(phenolate) ligands are described. Bimetallic complexes (ZnEt)2[L1] (1a), its THF adduct (ZnEt)2[L1]·THF (1a·THF), and (ZnEt)2[L2] (1b) (where [L1] = n-propylamine-N,N-bis(2-methylene-4,6-di-t-butylphenolate) and [L2] = n-propylamine-N,N-bis(2-methylene-6-t-butyl-4-methylphenolate) were prepared via reaction of the proligands H2[L1] and H2[L2] with ZnEt2. The addition of isopropanol to complex 1a to replace the ethyl groups with more nucleophilic alkoxyl groups afforded trimetallic zinc complex Zn3(i-PrO)2[L1]2 (3).

Evolution of the rodent Trim5 cluster is marked by divergent paralogous expansions and independent acquisitions of TrimCyp fusions.

Evolution of cellular innate immune genes in response to viral threats represents a rich area of study for understanding complex events that shape mammalian genomes. One of these genes, TRIM5, is a retroviral restriction factor that mediates a post-entry block to infection. Previous studies on the genomic cluster that contains TRIM5 identified different patterns of gene amplification and the independent birth of CypA gene fusions in various primate species.

Iron Complexes for Cyclic Carbonate and Polycarbonate Formation: Selectivity Control from Ligand Design and Metal-Center Geometry.

A family of 17 iron(III) aminobis(phenolate) complexes possessing different phenolate substituents, coordination geometries, and donor arrangements were used as catalysts for the reaction of carbon dioxide (CO) with epoxides. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of the iron complexes with a bis(triphenylphosphine)iminium chloride cocatalyst in negative mode revealed the formation of six-coordinate iron "ate" species. Under low catalyst loadings (0.

Mutational analysis and glycosylation sensitivity of restrictive XPR1 gammaretrovirus receptors in six mammalian species.

Most viruses infect only a few hosts, but the xenotropic and polytropic mouse leukemia viruses (X/P-MLVs) are broadly infectious in mammalian species. X/P-MLVs use the XPR1 receptor for cell entry, and tropism differences are due to polymorphisms in XPR1 and the viral envelope. To characterize these receptor variants and identify blocks to cross-species transmission, we examined the XPR1 receptors in six mammalian species that restrict different subsets of X/P-MLVs.

Distribution of endogenous gammaretroviruses and variants of the Fv1 restriction gene in individual mouse strains and strain subgroups.

Inbred laboratory mouse strains carry endogenous retroviruses (ERVs) classed as ecotropic, xenotropic or polytropic mouse leukemia viruses (E-, X- or P-MLVs). Some of these MLV ERVs produce infectious virus and/or contribute to the generation of intersubgroup recombinants. Analyses of selected mouse strains have linked the appearance of MLVs and virus-induced disease to the strain complement of MLV E-ERVs and to host genes that restrict MLVs, particularly Fv1.

Water quality dynamic during rainfall episodes: integrated approach to assess diffuse pollution using automatic sampling.

Diffuse pollution caused by rainfall events potentially affects water quality in rivers and, therefore, must be investigated in order to improve water quality planning and management recovery strategies. For these, a quali-quantitative approach was used to monitor the water quality parameters in a river located in a semi-urban watershed area based upon automatic sampling. Thirteen water quality parameters were measured during five rainfall events.

Cobalt amino-bis(phenolate) complexes for coupling and copolymerization of epoxides with carbon dioxide.

Cobalt(ii) and (iii) complexes bearing tetradentate amino-bis(phenolate) ligands containing either pendent dimethylaminoethylene or pyridyl groups and phenolates bearing electron-donating alkyl or electron-withdrawing chloro substituents were synthesized. The compounds were characterized by mass spectrometry, elemental analysis and NMR for diamagnetic compounds. The influence of the electron donating ability and steric demand of the ligands on CO2/epoxide ring-opening copolymerization (ROCOP) and coupling reactions was investigated.