La discusión sobre el desarrollo en el período de entreguerras: la perspectiva argentina y canadiense

El presente trabajo se dedica a investigar, desde las perspectivas de la historia de las ideas, los debates económicos presentes en la Argentina y el Canadá en la primera parte del siglo XX. Reviste especial interés, porque más allá de las diferencias en los estadios de desarrollo -mientras el país del norte ya se encontraba en un franco proceso de industrialización sustitutiva, en el sur se discutía su viabilidad- la discusión nos permite establecer la existencia de dos tradiciones económicas visibles en ambos hemisferios. Por un lado, aquella más cercana a las exigencias del mercado, que se traducen en las posiciones continentalista en Canadá y agrarista en la Argentina. Frente a estas posturas, que buscan adecuarse a los vaivenes de las fuerzas económicas, encontramos otras, que señalan los riesgos de dejarse arrastrar por el mercado y olvidar la necesidad de conservar los mínimos instrumentos de política económica nacional. La visión crítica de Harold Innis y el industrialismo de Alejandro Bunge encarnan este desafío, que conserva actualmente su vigencia.Fil: Lucchini, María Cristina. Universidad de Buenos Aires. Facultad de Ciencias Económicas; Argentina.Fil: Blanco, Teodoro V. Universidad de Buenos Aires. Facultad de Ciencias Económicas; Argentina.Fil: Cerra, Angel. Universidad de Buenos Aires. Facultad de Ciencias Económicas; Argentina

Ionic Liquids Made with Dimethylcarbonate: Solvents as well as Boosted Basic Catalysts for the Michael Reaction

Abstract: This article describes 1) a methodology for the green synthesis of a class of methylammonium and methylphosphonium ionic liquids (ILs), 2) how to tune their acid–base properties by anion exchange, 3) complete neat-phase NMR spectroscopic characterisation of these materials and 4) their application as active organocatalysts for base-promoted carbon– carbon bond-forming reactions. Methylation of tertiary amines or phosphines with dimethyl carbonate leads to the formation of the halogen-free methyl-onium methyl carbonate salts, and these can be easily anion-exchanged to yield a range of derivatives with different melting points, solubility, acid–base properties, stability and viscosity. Treatment with water, in particular, yields bicarbonate-exchanged liquid onium salts. These proved strongly basic, enough to efficiently catalyse the Michael reaction; experiments suggest that in these systems the bicarbonate basicity is boosted by two orders of magnitude with respect to inorganic bicarbonate salts. These basic ionic liquids used in catalytic amounts are better even than traditional strong organic bases. The present work also introduces neat NMR spectroscopy of the ionic liquids as a probe for solute– solvent interactions as well as a tool for characterisation. Our studies show that high catalytic efficacy of functional ionic liquids can be achieved by integrating their green synthesis, along with a fine-tuning of their structure. Demonstrating that ionic liquid solvents can be made by a truly green procedure, and that their properties and reactivity can be tailored to the point of bridging the gap between their use as solvents and as catalysts. Keywords: dimethyl carbonate · green chemistry · ionic liquids · Michael addition · NMR spectroscop

Prolactin Changes as a Consequence of Chemical Exposure

(LETTER

New Triterpenes from the Fungus Gloeophyllum odoratum

Two new triterpene acids (1, 2), together with a complex mixture of lecithins (3), were isolated from the fungus Gloeophyllum odoratum. Their structures were elucidated on the basis of extensive spectroscopic analyses. The extract of Gloeophyllum odoratum considerably inhibited thrombin (72% at a concentration of 120 g/mL); the less polar fraction of the methanolic extract from the mushroom exhibited interesting activity (47% at a concentration of 120 g/mL) against thrombin. Compounds 1 and 2 were responsible for this activity

The prototype X-ray binary GX 339-4:using TeV γ-rays to assess LMXBs as Galactic cosmic ray accelerators

Since the discovery of cosmic rays (CRs) over a century ago, their origin remains an open question. Galactic CRs with energy up to the knee ($10^{15}$ eV) are considered to originate from supernova remnants, but this scenario has recently been questioned due to lack of TeV $\gamma$-ray counterparts in many cases. Extragalactic CRs on the other hand, are thought to be associated with accelerated particles in the relativistic jets launched by supermassive accreting black holes at the center of galaxies. Scaled down versions of such jets have been detected in X-ray binaries hosting a stellar black hole (BHXBs). In this work, we investigate the possibility that the smaller-scale jets in transient outbursts of low-mass BHXBs could be sources of Galactic CRs. To better test this scenario, we model the entire electromagnetic spectrum of such sources focusing on the potential TeV regime, using the `canonical' low-mass BHXB GX 339-4 as a benchmark. Taking into account both the leptonic radiative processes and the $\gamma$-rays produced via neutral pion decay from inelastic hadronic interactions, we predict the GeV and TeV $\gamma$-ray spectrum of GX 339-4 using lower-frequency emission as constraints. Based on this test-case of GX 339-4 we investigate whether other, nearby low-mass BHXBs could be detected by the next-generation very-high-energy $\gamma$-ray facility the Cherenkov Telescope Array, which would establish them as additional and numerous potential sources of CRs in the Galaxy.Comment: 13 pages, 12 figures, accepted to MNRA

25-hydroxyvitamin D concentrations are lower in patients with positive PCR for SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), with a clinical outcome ranging from mild to severe, including death. To date, it is unclear why some patients develop severe symptoms. Many authors have suggested the involvement of vitamin D in reducing the risk of infections; thus, we retrospectively investigated the 25-hydroxyvitamin D (25(OH)D) concentrations in plasma obtained from a cohort of patients from Switzerland. In this cohort, significantly lower 25(OH)D levels (p = 0.004) were found in PCR-positive for SARS-CoV-2 (median value 11.1 ng/mL) patients compared with negative patients (24.6 ng/mL); this was also confirmed by stratifying patients according to age >70 years. On the basis of this preliminary observation, vitamin D supplementation might be a useful measure to reduce the risk of infection. Randomized controlled trials and large population studies should be conducted to evaluate these recommendations and to confirm our preliminary observation

The Experience in Nicaragua: Childhood Leukemia in Low Income Countries—The Main Cause of Late Diagnosis May Be “Medical Delay”

Background. The event-free survival for pediatric leukemia in low-income Countries is much lower than in high-income countries. Late diagnosis, which is regarded as a contributing factor, may be due to “parental” or “medical” delay. Procedures. The present study analyses determinants of lag time from first symptoms to diagnosis of leukemia, comparing pediatric (0–16 years old) patients in two referral centers, one in Nicaragua and one in Italy. An observational retrospective study was conducted to assess factors influencing the time to diagnosis. Results. 81 charts of children diagnosed with acute myeloid leukemia or lymphoblastic leukemia were analyzed from each centre. Median lag time to diagnosis was higher in Nicaragua than in Italy (29 versus 14 days, P < 0.001) and it was mainly due to “physician delay” (16.5 versus 7 days, P < 0.001), whereas “patient delay” from symptoms to first medical assessment was similar in the two centers (7 versus 5 days, P = 0.27). Moreover, median lag time from symptoms to diagnosis was decreased in Nicaraguan districts were a specific training program upon childhood oncological diseases was carried out (20.5 versus 40 days, P = 0.0019). Conclusions. Our study shows that delay in diagnosis of childhood leukemia is mainly associated with “physician delay” and it may be overcome by programs of continuous medical education