Aristoburocracia

Les invito a leer este documento, lo que ha cabido en los límites de una revista, presentado por su autor en la Magdalena como si de una estimulante conferencia en una escuela de negocios se tratase, servida con una explícita serie de gráficos, además, de elaboración propia y contundente argumentario, que nunca dejó de ser amable. De nuevo agradecemos a Juan José Güemes su amistosa y aplaudida participación en Santander

SARS-CoV-2 Droplet and Airborne Transmission Heterogeneity

The spread dynamics of the SARS-CoV-2 virus have not yet been fully understood after two years of the pandemic. The virus’s global spread represented a unique scenario for advancing infectious disease research. Consequently, mechanistic epidemiological theories were quickly dismissed, and more attention was paid to other approaches that considered heterogeneity in the spread. One of the most critical advances in aerial pathogens transmission was the global acceptance of the airborne model, where the airway is presented as the epicenter of the spread of the disease. Although the aerodynamics and persistence of the SARS-CoV-2 virus in the air have been extensively studied, the actual probability of contagion is still unknown. In this work, the individual heterogeneity in the transmission of 22 patients infected with COVID-19 was analyzed by close contact (cough samples) and air (environmental samples). Viral RNA was detected in 2/19 cough samples from patient subgroups, with a mean Ct (Cycle Threshold in Quantitative Polymerase Chain Reaction analysis) of 25.7 ± 7.0. Nevertheless, viral RNA was only detected in air samples from 1/8 patients, with an average Ct of 25.0 ± 4.0. Viral load in cough samples ranged from 7.3 × 105 to 8.7 × 108 copies/mL among patients, while concentrations between 1.1–4.8 copies/m3 were found in air, consistent with other reports in the literature. In patients undergoing follow-up, no viral load was found (neither in coughs nor in the air) after the third day of symptoms, which could help define quarantine periods in infected individuals. In addition, it was found that the patient’s Ct should not be considered an indicator of infectiousness, since it could not be correlated with the viral load disseminated. The results of this work are in line with proposed hypotheses of superspreaders, which can attribute part of the heterogeneity of the spread to the oversized emission of a small percentage of infected people

Juan de la Cruz Güemes Campero a Benito de Otero

Copi

Rubber modified epoxy resins cured with piperidine

Glass transition temperatures (Tᵍ) of epoxy resins, diglycidyl ether of bisphenol-A cured with piperidine, have been measured by differential scanning calorimetry and dynamic mechanical thermal analysis in order to follow the curing process. Optimum cure conditions have been established as 3% PP at 120°C. Tᵍs of the neat epoxy system and those modified with 5 and 16% of a carboxyl-terminated reactive rubber copolymer of butadiene and acrylonitrile (CTBN) have been determined as a function of the cure time. Addition of 5% of CTBN does not modify the process, but the higher CTBN content accelerates the initial stage. Tᵍs after long cure times (Tᵍx) are lower for the modified systems than for the neat, showing that CTBN is not fully segregated. The amounts of CTBN dissolved in the epoxy crosslinked network have been estimated.The authors thank Dr A. J. Kinloch for advice in this investigation. We are grateful to CIBAGEIGY for kindly providing the samples. Financial support by the Comisión de lnvestigación Científica y Técnica is acknowledged (89/0435)

Reactivity of Tuck-over Titanium Oxo Complexes with Isocyanides

The reactivity of the "tuck-over" species [Ti2(η5-C5Me5)(CH2Ph)3(μ-η5-C5Me4CH2-κC)(μ-O)] (1) and [Ti2(η5-C5Me5)(CH2CMe3)(μ-η5-C5Me4CH2-κC)(μ-CH2CMe2CH2)(μ-O)] (2) toward isocyanides has been examined both synthetically and theoretically. Treatment of 1with the isocyanides RNC, R = Me3SiCH2, 2,6-Me2C6H3, tBu,iPr, leads to a series of η2-iminoacyl species (3−6) where the molecule of isocyanide inserts into one of the terminal metal−alkyl bonds. The analogous reaction of the "tuck-over" metallacycle species 2 with 2,6-Me2C6H3NC andtBuNC results inthe initial insertion of one isocyanide into the terminal Ti−alkyl bondto form the iminoacyl complexes 7 and 8, followed by a secondinsertion into the metallacycle moiety to generate 9, in the case of tertbutylisocyanide. DFT calculations support the selective reactivity observed experimentally with a kinetic and thermodynamicpreference for RNC insertion on the terminal alkyl groups bound to both metallic centers over the alternative insertion on the "tuck-over"ligand.Ministerio de Economía y Competitividad Universidad de Alcal

Structural Diversity in the Reactions of Dimetallic Alkyl Titanium Oxides with Isonitriles and Nitriles.

A detailed study of the reaction of the dinuclear [{Ti(eta(5)-C5Me5)R-2}(2)(mu-O)] (R = Me 1, CH2Ph 2) compounds with a series of organic isonitriles (R'NC, R' = tBu, iPr, CH2SiMe3, Xyl) (Xyl = 2,6-Me2C6H3) and nitriles (R'CN, R' = tBu, iPr, SiMe3) has been carried out. Single-crystal X-ray structural studies revealed a variety of reactivity and structural moieties. Theoretical calculations (density functional theory, DFT) were used to understand the mechanism of some uncommon reactions observed experimentally. Reactions of 1 and 2 with isocyanides tBuNC, iPrNC, and Me3SiCH2NC led to the formation of dimetallic eta(2)-iminoacyl species [{Ti(eta(5)-C5Me5)(R'NCR)R}(2)(mu-O)] (R = Me, R' = tBu 3, iPr 4, CH2SiMe3 5; R = CH2Ph, R' = CH2SiMe3 6). Complex 4 underwent net rearrangements at room temperature to give the imido-vinylamido derivative [Ti-2(eta(5)-C5Me5)(2)(mu-O)(mu-NiPr) {N(iPr)CMe=CMe2}Me] (7), whereas the reaction of complex 2 with XylNC rendered the N-C bond cleavage product [{Ti(eta(5)-C5Me5)(CH=CHPh)}(mu-O)(mu-kappa(2)-N,C-N(MeC6H3)CH2){Ti(eta(5)-C5Me5)}] (8). The reactions of 1 with nitriles tBuCN and iPrCN gave the ketimido products [{Ti(eta(5)-C5Me5)Me(CN(Me)R')}(2) (mu-O)] (R' = tBu 9, iPr 10), whereas the analogous processes with 2 gave the alkenyl-imido complexes [{Ti(eta(5)-C5Me5)(CH2Ph)(2)}(mu-O){Ti(eta(5)-C5Me5)(=NC(R')=C(H)Ph)(NCR')}] (R' = tBu 11, iPr 12) with the concomitant coordination of a nitrile molecule. Complex 1 reacts with Me3SiCN to afford the nitrile-isonitrile isomerization product [{Ti(eta(5)-C5Me5)Me-2}(mu-O){Ti(eta(5)-C5Me5)(kappa(2)-C,N-Me-2 CNSiMe3 )(CNSiMe3)] (13).Consorcio Madroño - Universidad de Alcal

Capacidades infraestructurales y la construcción de sinergias estatales para el desarrollo : Buscando al "enraizamiento" en las políticas de promoción a los actores económico territoriales, en el Estado provincial de Santa Fe, de los '90

Partiendo de comprender la centralidad que adquiere la adopción, por parte de las estructuras estatales (en este caso las regionales), de la capacidad para penetrar en la sociedad y desarrollar un alto poder operativo a partir de nutrirse de las energías, conocimientos y recursos de esta. Realizamos un estudio sobre la existencia y calidad de esta que denominamos capacidad infraestructural, dentro de oficinas estratégicamente prioritarias del Estado provincial de Santa Fe, durante la década del '90. Sobre estas oficinas, seleccionadas por encontrarse directamente vinculadas a la producción e implementación de políticas de desarrollo del sistema productivo industrial regional, veremos primero aquellas estrategias de vinculación encaradas por el Estado regional hacia la sociedad, evaluando dentro de los programas que implementa para ello, la existencia de instancias de participación conjunta con los actores territoriales directamente implicados, ya sea dentro de los objetivos originalmente formulados o como resultado de su desarrollo. Luego de esta mirada hacia el actor estatal, consideraremos al enraizamiento desde la visión de los propios actores institucionales y socioeconómicos implicados en las acciones más significativas realizadas por el Estado regional. Allí indagaremos especialmente el modo en que los actores territoriales perciben a los procesos de involucramiento y el impacto de las políticas encaradas, para la creación de condiciones institucionales y económicas favorables, verificando si estos actores reconocen en ellas un mecanismo de participación y actuación conjunta con el EstadoFacultad de Humanidades y Ciencias de la Educació

Extremity tourniquet training at high seas

Background Future navy officers require unique training for emergency medical response in the isolated maritime environment. The authors issued a workshop on extremity bleeding control, using four different commercial extremity tourniquets onboard a training sail ship. The purposes were to assess participants' perceptions of this educational experience and evaluate self-application simplicity while navigating on high seas. Methods A descriptive observational study was conducted as part of a workshop issued to volunteer training officers. A post-workshop survey collected their perceptions about the workshops' content usefulness and adequacy, tourniquet safety, self-application simplicity, and device preference. Tourniquet preference was measured by frequency count while the rest of the studied variables on a one-to-ten Likert scale. Frequencies and percentages were calculated for the studied variables, and application simplicity means compared using the ANOVA test (p < 0.05). Results Fifty-one Spanish training naval officers, aged 20 or 21, perceived high sea workshop content’s usefulness, adequacy, and safety level at 8.6/10, 8.7/10, and 7.5/10, respectively. As for application simplicity, CAT and SAM-XT were rated equally with a mean of 8.5, followed by SWAT (7.9) and RATS (6.9), this one statistically different from the rest (p < 0.01). Windlass types were preferred by 94%. Conclusions The training sail ship’s extremity bleeding control workshop was perceived as useful and its content adequate by the participating midshipmen. Windlass types were regarded as easier to apply than elastic counterparts. They were also preferred by nine out of every ten participants