Can a Soil Mineralization Test Improve Wheat and Corn Nitrogen Diagnosis?

A network of field studies determined that the traditional method for predicting soil N availability …a pre-plant nitrate test … can be combined with an indicator of soil N mineralization capacity to significantly improve the diagnosis for soil N availability for both wheat and corn.Fil: Reussi Calvo, Nahuel Ignacio. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina. Laboratiorio de Suelos. Fertilab; ArgentinaFil: Echeverría, Hector E.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Sainz Rozas, Hernan Rene. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Berardo, Angel. Laboratiorio de Suelos. Fertilab; ArgentinaFil: Diovisalvi, Natalia. Laboratiorio de Suelos. Fertilab; Argentin

Modelling the Excited State Properties of TiO2 Nanoparticles

Since the discovery in 1972 of photocatalytic water splitting on TiO2 electrodes, there has been a worldwide research effort focused on the study of this material. Recently, it was shown that the use of nanosized systems could overcome the usual TiO2 limitations, e.g. a too large band gap, and increase its efficiency in photocatalytic applications. This thesis involves the computational modelling of excited state properties of TiO2 nanoparticles in order to provide atomic scale insights into the optical and photocatalytic properties of these materials. In the first part of this thesis, accurate correlated wave function benchmarks (i.e. EOM-CC) are defined for the calculation of excited states of small TiO2 nanoparticles (< 1 nm in size). These results are then employed for the evaluation of the accuracy of different Time Dependent DFT (TDDFT) exchange-correlation (XC) potentials. The main conclusion is that standard TDDFT XC energy functionals (e.g. PBE, B3LYP) tend to underestimate charge transfer excitations, whereas long-range corrected (e.g. CAM-B3LYP) potentials accurately describe optical properties of TiO2 nanoparticles. Following this study, in an effort to close the gap between simple theoretical models and systems of experimental relevance, TD-DFT is used for the investigation of a range of optical and excited state properties for a rutile bulk-like particle with a diameter of approximately 2 nm. These studies reveal that this or smaller rutile nanoparticles are predicted to be thermodynamically unable to drive photocatalytic water splitting because of the strong self-trapping of free electrons and holes generated during the excitation process in these particles. Finally, the excited state lifetimes and the photo-reactivity of a small hydrated TiO2 particle were investigated by employing TD-DFT non-adiabatic excited state molecular dynamics (NAMD). This study corresponds to a first attempt of using TD-DFT touncover the initial steps of the photochemical water-splitting reaction catalysed by TiO2 nanoparticles. The results from this thesis suggest that in the case of the TD-B3LYP trajectories, the first steps of the water splitting reaction mechanism are found to be heterolytic in character

Amine molecular cages as supramolecular fluorescent explosive sensors: a computational perspective

We investigate using a computational approach the physical and chemical processes underlying the application of organic (macro)molecules as fluorescence quenching sensors for explosives sensing. We concentrate on the use of amine molecular cages to sense nitroaromatic analytes, such as picric acid and 2,4-dinitrophenol, through fluorescence quenching. Our observations for this model system hold for many related systems. We consider the different possible mechanisms of fluorescence quenching: Förster resonance energy transfer, Dexter energy transfer and photoinduced electron transfer, and show that in the case of our model system, the fluorescence quenching is driven by the latter and involves stable supramolecular sensor–analyte host–guest complexes. Furthermore, we demonstrate that the experimentally observed selectivity of amine molecular cages for different explosives can be explained by the stability of these host–guest complexes and discuss how this is related to the geometry of the binding site in the sensor. Finally, we discuss what our observations mean for explosive sensing by fluorescence quenching in general and how this can help in future rational design of new supramolecular detection systems

Higher expression of vascular endothelial growth factor (VEGF) and its receptor VEGFR-2 (Flk-1) and metalloproteinase-9 (MMP-9) in a rat model of peritoneal endometriosis is similar to cancer diseases

<p>Abstract</p> <p>Background</p> <p>Endometriosis is a common disease characterized by the presence of a functional endometrium outside the uterine cavity, causing pelvic pain, dysmenorrheal, and infertility. This disease has been associated to development of different types of malignancies; therefore new blood vessels are essential for the survival of the endometrial implant. Our previous observations on humans showed that angiogenesis is predominantly found in rectosigmoid endometriosis, a deeply infiltrating disease. In this study, we have established the experimental model of rat peritoneal endometriosis to evaluate the process of angiogenesis and to compare with eutopic endometrium.</p> <p>Methods</p> <p>We have investigated the morphological characteristics of these lesions and the vascular density, VEGF and its receptor Flk-1 and MMP-9 expression, and activated macrophage distribution, using immunohistochemistry and RT-PCR.</p> <p>Results</p> <p>As expected, the auto-transplantation of endometrium pieces into the peritoneal cavity is a well-established method for endometriosis induction in rats. The lesions were cystic and vascularized, and demonstrated histological hallmarks of human pathology, such as endometrial glands and stroma. The vascular density and the presence of VEGF and Flk-1 and MMP-9 were significantly higher in endometriotic lesions than in eutopic endometrium, and confirmed the angiogenic potential of these lesions. We also observed an increase in the number of activated macrophages (ED-1 positive cells) in the endometriotic lesions, showing a positive correlation with VEGF.</p> <p>Conclusion</p> <p>The present endometriosis model would be useful for investigation of the mechanisms of angiogenesis process involved in the peritoneal attachment of endometrial cells, as well as of the effects of therapeutic drugs, particularly with antiangiogenic activity.</p

Subcutaneous Adipose Tissue Transcriptome Highlights Specific Expression Profiles in Severe Pediatric Obesity: A Pilot Study

The prevalence of pediatric obesity is rising rapidly worldwide, and "omic" approaches are helpful in investigating the molecular pathophysiology of obesity. This work aims to identify transcriptional differences in the subcutaneous adipose tissue (scAT) of children with overweight (OW), obesity (OB), or severe obesity (SV) compared with those of normal weight (NW). Periumbilical scAT biopsies were collected from 20 male children aged 1-12 years. The children were stratified into the following four groups according to their BMI z-scores: SV, OB, OW, and NW. scAT RNA-Seq analyses were performed, and a differential expression analysis was conducted using the DESeq2 R package. A pathways analysis was performed to gain biological insights into gene expression. Our data highlight the significant deregulation in both coding and non-coding transcripts in the SV group when compared with the NW, OW, and OB groups. A KEGG pathway analysis showed that coding transcripts were mainly involved in lipid metabolism. A GSEA analysis revealed the upregulation of lipid degradation and metabolism in SV vs. OB and SV vs. OW. Bioenergetic processes and the catabolism of branched-chain amino acids were upregulated in SV compared with OB, OW, and NW. In conclusion, we report for the first time that a significant transcriptional deregulation occurs in the periumbilical scAT of children with severe obesity compared with those of normal weight or those with overweight or mild obesity

Friction of rough surfaces on ice: Experiments and modeling

N.M. Pugno is supported by the European Research Council [ERC StG Ideas 2011 BIHSNAM n. 279985, ERC PoC 2013 KNOTOUGH n. 632277, ERC PoC 2015 SILKENE nr. 693670], by the European Commission under the Graphene Flagship [WP14 “Nanocomposites”, n. 604391]. D. Marchetto and S. Valeri gratefully acknowledge the support by Cost ActionMP1303 “Understanding and controlling nano and mesoscale friction”

Modeling Excited States in TiO2 Nanoparticles: On the Accuracy of a TD-DFT Based Description.

We have investigated the suitability of Time-Dependent Density Functional Theory (TD-DFT) to describe vertical low-energy excitations in naked and hydrated titanium dioxide nanoparticles. Specifically, we compared TD-DFT results obtained using different exchange-correlation (XC) potentials with those calculated using Equation-of-Motion Coupled Cluster (EOM-CC) quantum chemistry methods. We demonstrate that TD-DFT calculations with commonly used XC potentials (e.g., B3LYP) and EOM-CC methods give qualitatively similar results for most TiO2 nanoparticles investigated. More importantly, however, we also show that, for a significant subset of structures, TD-DFT gives qualitatively different results depending upon the XC potential used and that only TD-CAM-B3LYP and TD-BHLYP calculations yield results that are consistent with those obtained using EOM-CC theory. Moreover, we demonstrate that the discrepancies for such structures originate from a particular combination of defects that give rise to charge-transfer excitations, which are poorly described by XC potentials that do not contain sufficient Hartree-Fock like exchange. Finally, we consider that such defects are readily healed in the presence of ubiquitously present water and that, as a result, the description of vertical low-energy excitations for hydrated TiO2 nanoparticles is nonproblematic

Bone Marrow Mesenchymal Stem Cells Expanded Inside the Nichoid Micro-Scaffold: a Focus on Anti-Inflammatory Response

Purpose Mesenchymal stem cells (MSCs) represent a promising source for stem cell therapies in numerous diseases, including pediatric respiratory system diseases. Characterized by low immunogenicity, high anti-inflammatory, and immunoregulatory features, MSCs demonstrated an excellent therapeutic profile in numerous in vitro and preclinical models. MSCs reside in a specialized physiologic microenvironment, characterized by a unique combination of biophysical, biochemical, and cellular properties. The exploitation of the 3D micro-scaffold Nichoid, which simulates the native niche, enhanced the anti-inflammatory potential of stem cells through mechanical stimulation only, overcoming the limitation of biochemical and xenogenic growth factors application.Materials and Methods In this work, we expanded pediatric bone marrow MSCs (BM-MSCs) inside the Nichoid and performed a complete cellular characterization with different approaches including viability assays, immunofluorescence analyses, RNA sequencing, and gene expression analysis.Results We demonstrated that BM-MSCs inside the scaffold remain in a stem cell quiescent state mimicking the condition of the in vivo environment. Moreover, the gene expression profile of these cells shows a significant up-regulation of genes involved in immune response when compared with the flat control.Conclusion The significant changes in the expression profile of anti-inflammatory genes could potentiate the therapeutic effect of BM-MSCs, encouraging the possible clinical translation for the treatment of pediatric congenital and acquired pulmonary disorders, including post-COVID lung manifestations