A climate threshold for ocean deoxygenation during the Early Cretaceous.

Oceanic anoxic events (OAEs) are historical intervals of global-scale ocean deoxygenation associated with hyperthermal climate states and biological crises. Massive volcanic carbon dioxide (CO) emissions frequently associated with these events are thought to be a common driver of ocean deoxygenation through several climate-warming-related mechanisms. The Early Cretaceous OAE1a is one of the most intense ocean deoxygenation events, persisting for more than 1 Myr (refs.

The Complementarity of Nuclear Magnetic Resonance and Native Mass Spectrometry in Probing Protein-Protein Interactions.

Nuclear magnetic resonance (NMR) and native mass spectrometry (MS) are mature physicochemical techniques with long histories and important applications. NMR spectroscopy provides detailed information about the structure, dynamics, interactions, and chemical environment of biomolecules. MS is an effective approach for determining the mass of biomolecules with high accuracy, sensitivity, and speed.

The plasma membrane-associated cation-binding protein PCaP1 of Arabidopsis thaliana is a uranyl-binding protein.

Uranium (U) is a naturally-occurring radionuclide that is toxic to living organisms. Given that proteins are primary targets of U(VI), their identification is an essential step towards understanding the mechanisms of radionuclide toxicity, and possibly detoxification. Here, we implemented a chromatographic strategy including immobilized metal affinity chromatography to trap protein targets of uranyl in Arabidopsis thaliana.

Carbon pump dynamics and limited organic carbon burial during OAE1a.

Oceanic Anoxic Events (OAEs) are conspicuous intervals in the geologic record that are associated with the deposition of organic carbon (OC)-rich marine sediment, linked to extreme biogeochemical perturbations, and characterized by widespread ocean deoxygenation. Mechanistic links between the marine biological carbon pump (BCP), redox conditions, and organic carbon burial during OAEs, however, remain poorly constrained. In this work we reconstructed the BCP in the western Tethys Ocean across OAE1a (~120 Mya) using sediment geochemistry and OC mass accumulation rates (OC ).

Impact of global cooling on Early Cretaceous high pCO world during the Weissert Event.

The Weissert Event ~133 million years ago marked a profound global cooling that punctuated the Early Cretaceous greenhouse. We present modelling, high-resolution bulk organic carbon isotopes and chronostratigraphically calibrated sea surface temperature (SSTs) based on an organic paleothermometer (the TEX proxy), which capture the Weissert Event in the semi-enclosed Weddell Sea basin, offshore Antarctica (paleolatitude ~54 °S; paleowater depth ~500 meters). We document a ~3-4 °C drop in SST coinciding with the Weissert cold end, and converge the Weddell Sea data, climate simulations and available worldwide multi-proxy based temperature data towards one unifying solution providing a best-fit between all lines of evidence.

Morpholino-based peptide oligomers: Synthesis and DNA binding properties.

The chemical structure of oligonucleotide analogues dictates the conformation of oligonucleotide analogue oligomers, their ability to hybridize complementary DNA and RNA, their stability to degradation and their pharmacokinetic properties. In a study aimed at investigating new analogues featuring a neutral backbone, we explored the ability of oligomers containing a morpholino-peptide backbone to bind oligonucleotides. Circular Dichroism studies revealed the ability of our oligomers to interact with DNA, molecular modelling studies revealed the interaction responsible for complex stabilization.

Impact of SARS-CoV-2 infection on the recovery of peripheral blood mononuclear cells by density gradient.

SARS-CoV-2 virus infection is responsible for coronavirus disease (COVID-19), which is characterised by a hyperinflammatory response that plays a major role in determining the respiratory and immune-mediated complications of this condition. While isolating peripheral blood mononuclear cells (PBMCs) from whole blood of COVID-19 patients by density gradient centrifugation, we noticed some changes in the floating properties and in the sedimentation of the cells on density medium. Investigating this further, we found that in early phase COVID-19 patients, characterised by reduced circulating lymphocytes and monocytes, the PBMC fraction contained surprisingly high levels of neutrophils.

Alternative Strategy to Obtain Artificial Imine Reductase by Exploiting Vancomycin/D-Ala-D-Ala Interactions with an Iridium Metal Complex.

Based on the supramolecular interaction between vancomycin (Van), an antibiotic glycopeptide, and D-Ala-D-Ala (DADA) dipeptides, a novel class of artificial metalloenzymes was synthesized and characterized. The presence of an iridium(III) ligand at the -terminus of DADA allowed the use of the metalloenzyme as a catalyst in the asymmetric transfer hydrogenation of cyclic imines. In particular, the type of link between DADA and the metal-chelating moiety was found to be fundamental for inducing asymmetry in the reaction outcome, as highlighted by both computational studies and catalytic results.

SARS-CoV-2 seroprevalence trends in healthy blood donors during the COVID-19 outbreak in Milan.

Background: The Milan metropolitan area in Northern Italy was among the most severely hit by the SARS-CoV-2 outbreak. The aim of this study was to examine the seroprevalence trends of SARS-CoV-2 in healthy asymptomatic adults, and the risk factors and laboratory correlates of positive tests.

Materials And Methods: We conducted a cross-sectional study in a random sample of blood donors, who were asymptomatic at the time of evaluation, at the beginning of the first phase (February 24 to April 8 2020; n=789).

Peptide grafting strategies before and after electrospinning of nanofibers.

Nanofiber films produced by electrospinning currently provide a promising platform for different applications. Although nonfunctionalized nanofiber films from natural or synthetic polymers are extensively used, electrospun materials combined with peptides are gaining more interest. In fact, the selection of specific peptides improves the performance of the material for biological applications and mainly for tissue engineering, mostly by maintaining similar mechanical properties with respect to the simple polymer.

Nucleobase morpholino β amino acids as molecular chimeras for the preparation of photoluminescent materials from ribonucleosides.

Bioinspired smart materials represent a tremendously growing research field and the obtainment of new building blocks is at the molecular basis of this technology progress. In this work, colloidal materials have been prepared in few steps starting from ribonucleosides. Nucleobase morpholino β-amino acids are the chimera key intermediates allowing Phe-Phe dipeptides' functionalization with adenine and thymine.

The soluble glycoprotein NMB (GPNMB) produced by macrophages induces cancer stemness and metastasis via CD44 and IL-33.

In cancer, myeloid cells have tumor-supporting roles. We reported that the protein GPNMB (glycoprotein nonmetastatic B) was profoundly upregulated in macrophages interacting with tumor cells. Here, using mouse tumor models, we show that macrophage-derived soluble GPNMB increases tumor growth and metastasis in Gpnmb-mutant mice (DBA/2J).

High resolution spatial analyses of trace elements in coccoliths reveal new insights into element incorporation in coccolithophore calcite.

Coccolithophores are phytoplanktonic algae which produce an exoskeleton made of single platelets of calcite named coccoliths. They are widespread in all oceans and directly impact the short- and long-term C cycle. The study of coccolith size, morphology and elemental composition reveals important information regarding the ability of the cell to calcify and on the factors that influence this process.

Health technology assessment-based approach to flow cytometric immunophenotyping of acute leukemias: a literature classification.

Objective: Acute leukemia (AL) is a broad, heterogeneous group of malignant diseases. The diagnostic workup of AL is based on several clinical and laboratory findings, including flow cytometric immunophenotyping. However, the role of this assay in the diagnosis of AL has not been systematically investigated.

On-resin multicomponent 1,3-dipolar cycloaddition of cyclopentanone-proline enamines and sulfonylazides as an efficient tool for the synthesis of amidino depsipeptide mimics.

Depsipeptides are biologically active peptide derivatives that possess a high therapeutic interest. The development of depsipeptide mimics characterized by a chemical diversity could lead to compounds with enhanced features and activity. In this work, an on-resin multicomponent procedure for the synthesis of amidino depsipeptide mimics is described.

Tetrahydro-4 H-(pyrrolo[3,4- d]isoxazol-3-yl)methanamine: A Bicyclic Diamino Scaffold Stabilizing Parallel Turn Conformations.

A tetrahydro-4 H-(pyrrolo[3,4- d]isoxazol-3-yl)methanamine scaffold was designed as a diamino derivative to stabilize parallel turn conformations. Its synthesis took advantage of a [1,3]-dipolar cycloaddition reaction between the nitrile oxide derived from the inexpensive enantiopure l -phenylalanine and N-benzyl-3-pyrroline. Two diastereoisomers were formed, whose distribution depends on the selected base.

Counteracting roles of MHCI and CD8 T cells in the peripheral and central nervous system of ALS SOD1 mice.

Background: The major histocompatibility complex I (MHCI) is a key molecule for the interaction of mononucleated cells with CD8T lymphocytes. We previously showed that MHCI is upregulated in the spinal cord microglia and motor axons of transgenic SOD1 mice.

Methods: To assess the role of MHCI in the disease, we examined transgenic SOD1 mice crossbred with β2 microglobulin-deficient mice, which express little if any MHCI on the cell surface and are defective for CD8 T cells.