Industria y posconvertibilidad: Argentina ante los desafíos de la integración productiva regional

Una serie de cambios estructurales ocurridos en Argentina a partir del año 2003 proponen a la industria como motor del desarrollo económico a través de diversas políticas públicas, entre ellas, la integración productiva regional (por su potencialidad para promover la sustitución de importaciones y la agregación de valor a las exportaciones). De esta forma, la misma, se convirtió en una de las principales preocupaciones de la política exterior argentina en el ámbito del MERCOSUR. En este marco, el presente trabajo pretende analizar las características que la integración productiva toma dentro del bloque regional, haciendo particular énfasis en el rol jugado por Argentina en este proceso.Instituto de Relaciones Internacionales (IRI

Industria y posconvertibilidad: Argentina ante los desafíos de la integración productiva regional

Una serie de cambios estructurales ocurridos en Argentina a partir del año 2003 proponen a la industria como motor del desarrollo económico a través de diversas políticas públicas, entre ellas, la integración productiva regional (por su potencialidad para promover la sustitución de importaciones y la agregación de valor a las exportaciones). De esta forma, la misma, se convirtió en una de las principales preocupaciones de la política exterior argentina en el ámbito del MERCOSUR. En este marco, el presente trabajo pretende analizar las características que la integración productiva toma dentro del bloque regional, haciendo particular énfasis en el rol jugado por Argentina en este proceso.Instituto de Relaciones Internacionales (IRI

Industria y posconvertibilidad: Argentina ante los desafíos de la integración productiva regional

Una serie de cambios estructurales ocurridos en Argentina a partir del año 2003 proponen a la industria como motor del desarrollo económico a través de diversas políticas públicas, entre ellas, la integración productiva regional (por su potencialidad para promover la sustitución de importaciones y la agregación de valor a las exportaciones). De esta forma, la misma, se convirtió en una de las principales preocupaciones de la política exterior argentina en el ámbito del MERCOSUR. En este marco, el presente trabajo pretende analizar las características que la integración productiva toma dentro del bloque regional, haciendo particular énfasis en el rol jugado por Argentina en este proceso.Instituto de Relaciones Internacionales (IRI

Differential regulation of iron regulatory element-binding protein(s) in cell extracts of activated lymphocytes versus monocytes-macrophages.

The intracellular iron level exerts a negative feedback on transferrin receptor (TfR) expression in cells requiring iron for their proliferation, in contrast to the positive feedback observed in monocytes-macrophages. It has been suggested recently that modulation of TfR and ferritin synthesis by iron is mediated through a cytoplasmic protein(s) (iron regulatory element-binding protein(s) (IRE-BP)), which interacts with ferritin and TfR mRNA at the level of hairpin structures (IRE), thus leading to inhibition of transferrin mRNA degradation and repression of ferritin mRNA translation. In the present study we have evaluated in parallel the level of TfR expression, ferritin, and IRE-BP in cultures of: (i) circulating human lymphocytes stimulated to proliferate by phytohemagglutinin (PHA) and (ii) circulating human monocytes maturing in vitro to macrophages. The cells were grown in either standard or iron-supplemented culture. TfR and ferritin expression was evaluated at both the protein and mRNA level. IRE-BP activity was measured by gel retardation assay in the absence or presence of beta-mercaptoethanol (spontaneous or total IRE-BP activity, respectively). Spontaneous IRE-BP activity, already present at low level in quiescent T lymphocytes, shows a gradual and marked increase in PHA-stimulated T cells from day 1 of culture onward. This increase is directly and strictly correlated with the initiation and gradual rise of TfR expression, which is in turn associated with a decrease of ferritin content. Both the rise of TfR and spontaneous IRE-BP activity are completely inhibited in iron-supplemented T cell cultures. In contrast, the total IRE-BP level is similar in both quiescent and PHA-stimulated lymphocytes, grown in cultures supplemented or not with iron salts. Monocytes maturing in vitro to macrophages show a sharp increase of spontaneous and, to a lesser extent, total IRE-BP; the addition of iron moderately stimulates the spontaneous IRE-BP activity but not the total one. Here again, the rise of spontaneous IRE-BP from very low to high activity is strictly related to the parallel increase of TfR expression and, suprisingly, also with a very pronounced rise of ferritin expression observed at both the mRNA and protein level. It is noteworthy the effect of beta-mercaptoethanol is cell specific, i.e. the ratio of total versus spontaneous IRE-BP activity is different in activated lymphocytes and maturing monocytes.(ABSTRACT TRUNCATED AT 400 WORDS

Iron up-modulates the expression of transferrin receptors during monocyte-macrophage maturation

Abstract We have investigated the effect of iron on the expression of transferrin receptors (TrfRs) and ferritin chains in cultures of human peripheral blood monocytes maturing to macrophages. Monocyte-macrophage maturation is associated with a gradual rise of Trf-binding capacity in the absence of cell proliferation. At all culture times, treatment with ferric ammonium citrate induces a dose-dependent rise of the Trf-binding level as compared with nontreated cells. Scatchard analysis revealed that this phenomenon is due to an increase in receptor number rather than an alteration in ligand-receptor affinity. Biosynthesis experiments indicated that the rise in number of TrfRs is due to an increase of receptor synthesis, which is associated with a sustained elevation of the TrfR RNA level. The up-regulation of TrfR synthesis is specific in that expression of other macrophage membrane proteins is not affected by iron addition. Conversely, addition of an iron chelator induced a slight decrease of TrfR synthesis. The expression of heavy and light ferritin chains at RNA and protein levels was markedly more elevated in cultured macrophages than in fresh monocytes, thus suggesting modulation of ferritin genes at transcriptional or post-transcriptional levels. Addition of iron salts to monocyte-macrophage cultures sharply stimulated ferritin synthesis but only slightly enhanced the level of ferritin RNA, thus indicating a modulation at the translational level. These results suggests that in cultured human monocytes-macrophages, iron up-regulates TrfR expression, thus in sharp contrast to the negative feedback reported in a variety of other cell types. These observations may shed light on the mechanism(s) of iron storage in tissue macrophages under normal conditions and possibly on the pathogenesis of diseases characterized by abnormal iron storage

Phase II trial of humanized anti-Lewis Y monoclonal antibody for advanced hormone receptor-positive breast cancer that progressed following endocrine therapy

OBJECTIVES: The Lewis-Y antigen is expressed in 44%-90% of breast cancers (BCs). The expression of the antigen in carcinoma tissue differs from that in normal tissues. This study aimed to evaluate the clinical benefit of the humanized anti-Lewis Y monoclonal antibody, hu3S193, in advanced hormone receptor-positive and Lewis Y-positive BC after administration of endocrine therapy (ET). METHODS: A single-arm phase II study was conducted in seven centers. Patients with advanced hormone receptor-positive BC who failed first-line ET were included. The inclusion criterion was the observation of tumoral expression of the Lewis Y antigen during immunohistochemistry. The treatment comprised hu3S193 antibody administration at weekly intravenous doses of 20 mg/m2 for 8-week cycles. The primary endpoint was the clinical benefit rate. ClinicalTrials.gov NCT01370239. RESULTS: The study stopped accrual following an unplanned interim analysis as the hu3S193 antibody lacked sufficient activity to justify continuation of the study. Twenty-two patients were enrolled, of whom 21 were included in the efficacy analysis. The clinical benefit rate was 19%, with four patients presenting with stable disease after 24 weeks. One patient with prolonged stable disease received medication for over 2 years. No partial or complete responses were observed. The median time to progression and overall survival was 5.4 and 37.5 months, respectively. CONCLUSIONS: The humanized anti-Lewis Y monoclonal antibody, hu3S193, exhibited insufficient activity in this cohort. However, the possibility of activity in a more strictly selected subgroup of patients with higher levels of Lewis Y tumoral expression cannot be overlooked

Contribution of high energy physics techniques to the medical imaging field

The purpose of this study was to show how advanced concepts of compact, lossless and "Time Of Flight" (TOF) capable electronics similar to those foreseen for the LHC and ILC experiments could be fairly and easily transferred to the medical imaging field through Positron Emission Tomography (PET). As a wish of explanation, the two overriding weaknesses of PET camera readout electronics, namely dead-time and timing resolution, were investigated analytically and with a Monte-Carlo simulator presently dedicated to this task. Results have shown there was room left for count rate enhancement through a huge decrease of the timing resolution well below the nanosecond. The novel electronics scheme suggested for PET in this paper has been partly inspired by the long experience led in High Energy Physics where the latter requirement is compulsory. Its structure entirely pipelined combined to a pixelation of the whole detector should allow dead-times to be suppressed, while the absence of devoted timing channel would remove the preponderant contributions to the timing resolution. To the common solution for timing would substitute an optimal filtering method witch clearly appears as a good candidate as timing resolution of a few tens of picoseconds may be achieved provided the shape of the signal is known and sufficient samples are available with enough accuracy. First investigations have yield encouraging results as a sampling frequency of 50 MHz with a 7 bits precision appears sufficient to ensure the 500ps coincidence timing resolution planed. At this point, there will be a baby step ahead to draw benefice from a TOF implementation to the design and the enormous noise variance enhancement that would come with.Comment: presented at EuroMedIm 2006 : 1st European Conference on Molecular Imaging Technology, Marseille 9-12 May 2006, 6 pp, 4 figures, submitted to NI

Stress Corrosion Cracking of Additively Manufactured Alloy 625

From MDPI via Jisc Publications RouterHistory: accepted 2021-10-12, pub-electronic 2021-10-15Publication status: PublishedLaser bed powder fusion (LPBF) is an additive manufacturing technology for the fabrication of semi-finished components directly from computer-aided design modelling, through melting and consolidation, layer upon layer, of a metallic powder, with a laser source. This manufacturing technique is particularly indicated for poor machinable alloys, such as Alloy 625. However, the unique microstructure generated could modify the resistance of the alloy to environment assisted cracking. The aim of this work was to analyze the stress corrosion cracking (SCC) and hydrogen embrittlement resistance behavior of Alloy 625 obtained by LPBF, both in as-built condition and after a standard heat treatment (grade 1). U-bend testing performed in boiling magnesium chloride at 155 and 170 °C confirmed the immunity of the alloy to SCC. However, slow strain rate tests in simulated ocean water on cathodically polarized specimens highlighted the possibility of the occurrence of hydrogen embrittlement in a specific range of strain rate and cathodic polarization. The very fine grain size and dislocation density of the thermally untreated specimens appeared to increase the hydrogen diffusion and embrittlement effect on pre-charged specimens that were deformed at the high strain rate. Conversely, heat treatment appeared to mitigate hydrogen embrittlement at high strain rates, however at the slow strain rate all the specimens showed a similar behavior