Arsenic, fluoride and other trace elements in the Argentina Pampean plain

The contents of arsenic (As), fluoride (F) and other trace elements (B, Cd, Cr, Cu, Fe, Mn, Ni, Pb, V, Zn, Ba, Si and Sr) have been determined in groundwater samples from the Langueyú creek basin, in the Argentina Pampean plain. This research aims to establish the baseline concentration and geographical distribution of trace elements in this basin. This aim has particular interest to public health in the city of Tandil where groundwater is the principal source of water for human supply. The baseline concentrations of elements in the Langueyú creek basin are in good agreement with published data from other locations of the Pampean aquifer. The arsenic limit of 10mg/l, established as provisional limit by the World Health Organization (WHO), was exceeded in 78% of the sampled wells, with As concentration increasing in the direction of groundwater flow. Concentrations of B, Cd, Cu, Cr, Fe, Mn, Ni, Pb and Zn regulated by the Argentinian Food Code (CAA) do not exceed the maximum limit for drinking water, although concentrations of Ni, Zn or Pb peaked up at some wells, probably due to pipeline corrosion. The strong correlation observed between As, F, V, Cr and B has been related to their anionic character at the groundwater natural alkaline pH that is likely associated with similar mobilization (adsorption/desorption) processes. Worst consequences for human health have arisen in areas with the highest arsenic concentration in drinking water. The conclusions of this study contribute to understand the provenance and mobilization processes of some trace elements in groundwater. It enables the decision making regarding the public health priorities and the technological treatments of water resources in urban and rural areas

Nota corta. Detección mediante PCR multiplex y caracterización de cepas no toxigénicas de Pseudomonas syringae pv. phaseolicola de distintas zonas de España

The efficient control of halo blight, caused by Pseudomonas syringae pv. phaseolicola, is primarily based on the use of pathogen-free seed. Detection of the pathogen in seeds is currently carried out with high-sensitive methods based on the detection by PCR of genes involved in the biosynthesis of phaseolotoxin, which was believed to be produced by all strains of the pathogen with epidemiological importance. However, field epidemics of halo blight in the county of Castilla y León, Spain, are often associated to nontoxigenic isolates of P. syringae pv. phaseolicola, which cannot be detected using current molecular and serological methods. The results presented in this work show the existence of nontoxigenic isolates of P. syringae pv. phaseolicola in areas other than Castilla y León, indicating the need to establish a reliable methodology for seed certification. A simple two-step methodology is presented with the aim to identify both types of isolates that is based on a multiplex enrichment PCR of seed soakates and on pathogenicity assays.El control eficiente de la grasa de la judía causada por Pseudomonas syringae pv. phaseolicola se basa principalmente en la utilización de semilla libre del patógeno. La detección del patógeno en semilla se efectúa mediante métodos altamente sensibles basados en la detección por PCR de los genes responsables de la biosíntesis de la faseolotoxina, la cual, hasta ahora, se consideraba que era sintetizada por todas las cepas del patógeno con importancia epidemiológica. Sin embargo, en la Comunidad de Castilla y León, España, las epidemias de grasa de la judía en campo se asocian frecuentemente con cepas no toxigénicas de P. syringae pv. phaseolicola, que no pueden ser detectadas con los métodos moleculares y serológicos actuales. Los resultados presentados en este trabajo demuestran la existencia de aislados no toxigénicos de P. syringae pv. phaseolicola en zonas distintas de Castilla y León, lo que implica la necesidad de establecer una metodología fiable para la certificación de semillas de judía. Con este propósito, se presenta un sencillo protocolo en dos fases que permite la identificación de los dos tipos de aislados, y que se basa en una PCR multiplex con enriquecimiento a partir de extractos de semilla y en ensayos de patogenicidad

Caracterización fisicoquímica de las aguas superficiales en la cuenca del Arroyo del Fuerte, Tandil

Fil: Cifuentes, M.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Humanas. Centro de Investigaciones y Estudios Ambientales; ArgentinaFil: Gabellone, Néstor A.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología Dr. Raúl Ringuelet; ArgentinaFil: Ruiz de Galarreta, Alejandro. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Humanas. Centro de Investigaciones y Estudios Ambientales; Argentin

Understanding elastic anisotropy in diamond based lattice structures produced by laser powder bed fusion: Effect of manufacturing deviations

Laser powder bed fusion (L-PBF) allows the production of metal lattice cellular structures with tailored mechanical properties. In order to generate the specific structural behavior it is of utmost importance to understand the response of the unit cells when different load conditions are considered. In this article the mechanical response of diamond based cellular structures has been investigated focusing on the impact of geometrical inaccuracy generated by the manufacturing process on the elastic anisotropy of the mentioned unit cell. The μ-CT analysis of the structures shows that the manufacturing deviations occur in certain orientations that depend highly on the building direction and proximity to nodes. The measured imperfection types were implemented in a finite element model in order to predict their single and combined effects in the elastic directional response. The results indicate that the L-PBF process can induce a significant change of elastic anisotropy in the diamond unit cells, including a substantial variation of the optimal orientation for minimal compliance. Methods are presented to calculate this anisotropy such that it can be taken into account when designing and using such lattice structures in real-life applications with multi-axial load condition

Additively manufactured lattice structures with controlled transverse isotropy for orthopedic porous implants

Additively manufactured lattice structures enable the design of tissue scaffolds with tailored mechanical properties, which can be implemented in porous biomaterials. The adaptation of bone to physiological loads results in anisotropic bone tissue properties which are optimized for site-specific loads; therefore, some bone sites are stiffer and stronger along the principal load direction compared to other orientations. In this work, a semi-analytical model was developed for the design of transversely isotropic lattice structures that can mimic the anisotropy characteristics of different types of bone tissue. Several design possibilities were explored, and a particular unit cell, which was best suited for additive manufacturing was further analyzed. The design of the unit cell was parameterized and in-silico analysis was performed via Finite Element Analysis. The structures were manufactured additively in metal and tested under compressive loads in different orientations. Finite element analysis showed good correlation with the semi-analytical model, especially for elastic constants with low relative densities. The anisotropy measured experimentally showed a variable accuracy, highlighting the deviations from designs to additively manufactured parts. Overall, the proposed model enables to exploit the anisotropy of lattice structures to design lighter scaffolds with higher porosity and increased permeability by aligning the scaffold with the principal direction of the load

Meeting high precision requirements of additively manufactured components through hybrid manufacturing

A hybrid approach combining the laser powder bed fusion (LPBF) process and post-processing operations through 5-axis milling was employed to manufacture a Ti6Al4V aerospace component. From the design step, the requirements and needs in all the stages of the Hybrid Additive Manufacturing process were taken into account. A numerical simulation of distortions promoted by residual stresses during the additive process was employed to consider material allowance. The status of the as-built and post-processed component was analysed through scanning and CMM inspection and roughness measurements. The 3D scanned model of the as-built LPBF-ed component was used to understand the distortion behaviour of the component and compared to the numerical simulation. Finally, 5-axis milling operations were conducted in some critical surfaces in order to improve surface quality and dimensional accuracy of the as-built com- ponent. The inspection of the as-built and post-processed component showed the improvement achieved through the proposed hybrid approach. The work aims to provide the baselines needed to enable the metal Hybrid Additive Manufacturing of components with complex geometries where mandatory precision is required by integrating high accuracy machining operations as post-processing technique

Phase-change meta-photonics

We combine phase-change materials and metamaterial arrays (metasurfaces) to create new forms of dynamic, tuneable and reconfigurable photonic devices including ‘perfect’ absorbers, infra-red light modulators, optical beam steerers and enhanced phase-change optoelectronic displays

Cold-Inducible RNA Binding Protein as a Vaccination Platform to Enhance Immunotherapeutic Responses against Hepatocellular Carcinoma

Therapies based on immune checkpoint inhibitors (ICPI) have yielded promising albeit limited results in patients with hepatocellular carcinoma (HCC). Vaccines have been proposed as combination partners to enhance response rates to ICPI. Thus, we analyzed the combined effect of a vaccine based on the TLR4 ligand cold-inducible RNA binding protein (CIRP) plus ICPI. Mice were immunized with vaccines containing ovalbumin linked to CIRP (OVA-CIRP), with or without ICPI, and antigen-specific responses and therapeutic efficacy were tested in subcutaneous and orthotopic mouse models of liver cancer. OVA-CIRP elicited polyepitopic T-cell responses, which were further enhanced when combined with ICPI (anti-PD-1 and anti-CTLA-4). Combination of OVA-CIRP with ICPI enhanced ICPI-induced therapeutic responses when tested in subcutaneous and intrahepatic B16-OVA tumors, as well as in the orthotopic PM299L HCC model. This effect was associated with higher OVA-specific T-cell responses in the periphery, although many tumor-infiltrating lymphocytes still displayed an exhausted phenotype. Finally, a new vaccine containing human glypican-3 linked to CIRP (GPC3-CIRP) induced clear responses in humanized HLA-A2.01 transgenic mice, which increased upon combination with ICPI. Therefore, CIRP-based vaccines may generate anti-tumor immunity to enhance ICPI efficacy in HCC, although blockade of additional checkpoint molecules and immunosuppressive targets should be also considered

Meeting high precision requirements of additively manufactured components through hybrid manufacturing

A hybrid approach combining the laser powder bed fusion (LPBF) process and post-processing operations through 5-axis milling was employed to manufacture a Ti6Al4V aerospace component. From the design step, the requirements and needs in all the stages of the Hybrid Additive Manufacturing process were taken into account. A numerical simulation of distortions promoted by residual stresses during the additive process was employed to consider material allowance. The status of the as-built and post-processed component was analysed through scanning and CMM inspection and roughness measurements. The 3D scanned model of the as-built LPBF-ed component was used to understand the distortion behaviour of the component and compared to the numerical simulation. Finally, 5-axis milling operations were conducted in some critical surfaces in order to improve surface quality and dimensional accuracy of the as-built com-ponent. The inspection of the as-built and post-processed component showed the improvement achieved through the proposed hybrid approach. The work aims to provide the baselines needed to enable the metal Hybrid Additive Manufacturing of components with complex geometries where mandatory precision is required by integrating high accuracy machining operations as post-processing technique.(c) 2022 The Author(s). This is an open access article under the CC BY license (http://creativecommons.org/ licenses/by/4.0/)