677 research outputs found

    Las bacterias un ejemplo de vida en comunidad

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    Una de las estrategias de éxito que existe en cualquier organización, es el trabajar por un bien común. Pues bien, un ejemplo claro de esta estrategia, está soportada por diferentes escritos en la literatura en relación a la formación de biopeliculas bacterianas, en las cuales se ha demostrado una excelente comunicación intercelular y múltiples mecanismos de supervivencia de la misma (1-14).Podría decirse que estos pequeños seres vivos tienen tan claro su objetivo, que conocen con certeza, que el trabajar en conjunto con otras bacterias de su misma especie o incluso especies diferentes, conlleva a un bien común: el colonizar, para garantizar la supervivencia continua de su especie (14). A pesar de que esta actitud podría considerarse de seres superiores, a los que se les dio la capacidad de pensar y analizar, las bacterias como seres vivos de tamaño microscópico y clasificado como seres inferiores, lo hacen por instinto natural, lo cual resulta ser una lección interesante para los llamados seres superiores: los humanos

    Evaluación en laboratorios e invernadero de extractos vegetales de barbasco (Pyllantus sp) Marigol (Tagetes patula) y semilla de Neem (Azadirachta A. Juss) para el control de Meloidogyne javanica y Fusarium oxysporum en tomate de mesa (Lycopersicon sculetum)

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    sumarios (En, Es)El cultivó de tomate (lycoperslcon scu/enlum) es una de las hortalizas de mayor área sembrada o nivel mundial, China ocupa el primer lugar en producción con 25.5 millones de toneladas seguido de USA con 2.3 millones de toneladas. Para el año de 1997 lo producción mundial de tomate de mesa fue de 88.7 millones de toneladas. En Colombia para el mismo año, el áreo sembrado fue de I 2,800 hectáreas para uno producción de 37 4 261 toneladas con lo cual participó en el mercado mundial con un 0.3% en exportaciones; el incremento en la producción desde 1998 al 2002 no creció más del 5% (FAOl998-2002) El tomate se cultivó en todo el país, o lo intemperie y bajo invernadero cerca del 80% de la producción está concentrada en los departamentos de Cundinamarca, Norte de Santander, Valle, Caldas. Huila, Tolima, Risaralda y Antioquia. Tradicionalmente se cultivan las variedades chonto y milano, pero en Atlántico, Guajira y Santander, se cultivan las variedades Rio Grande y Tomate Ciruelo.Tomate-Solanum lycopersicu

    Pyridinethiolate titanocene metalloligands and their self-assembly reactions to yield early–late metallamacrocycles

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    New titanocene pyridinethiolate compounds [(RCp)2Ti(4-Spy)2] (R = H (1), Me (2); Cp = cyclopentadienyl; 4-Spy = pyridine-4-thiolate) and [Cp2Ti(2-Spy)2] (3; 2-Spy = pyridine-2-thiolate) have been prepared by reaction of the corresponding Li(Spy) salt with the appropriate compound [(RCp)2TiCl2]. Compounds 1 and 2 have been used as metalloligands in self-assembly reactions with the acceptor late-transition-metal compounds [M(H2O)2(dppp)](OTf)2 (M = Pd (a) Pt (b); dppp = 1,3-bis(diphenylphosphino)propane), and the series of early–late tetranuclear metallamacrocycles [{(RCp)2Ti(4-Spy)2}{M(dppp)}]2(OTf)4 (R = H, M = Pd (12a2); R = H, M = Pt (12b2); R = Me, M = Pd (22a2); R = Me, M = Pt (22b2)) arising from the anti isomer of the titanocene metalloligands have been obtained. Only ligand transfer reactions from Ti to either Pd or Pt atoms have been observed when the pyridine-2-thiolate derivative 3 has been assayed in self-assembly processes. The obtained species have been characterized by NMR spectroscopy and ESI(+) mass spectrometry. The supramolecular assemblies have shown to be nonrigid in solution, and their fluxional behavior has been studied by VT 1H NMR spectroscopy. A DFT study including ab initio molecular dynamics in order to elucidate the structures and the relative stability of the isomers has been performed.Financial support for this work was provided by the Ministerio de Economía y Competitividad (MINECO/FEDER) of Spain (CTQ2013-42532-P and CTQ2012-31335), Diputación General de Aragón (Group E07) and Fondo Social Europeo. E.R. thanks Generalitat de Catalunya for an ICREA Academia fellowship.Peer reviewe

    Health-care guidelines and policies during the COVID-19 pandemic in Mexico: a case of health-inequalities

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    Background Heterogeneous government responses have been reported in reaction to COVID-19. The aim of this study is to generate an exploratory review of healthcare policies published during COVID-19 by health-care institutions in Mexico. Analyzing policies within different health sub-systems becomes imperative in the Mexican case due to the longstanding fragmentation of the health-care system and health inequalities. Data and Methods Policies purposely included in the analysis were published by four public health institutions (IMSS, ISSSTE, SSA and PEMEX) during the COVID-19 epidemic in Mexico (from February 29th to June 15th, 2020) on official institutional websites. Researchers reviewed each document and classified them into seven policy categories set by the Rapid Research Evaluation and Appraisal Lab (RREAL): public health response, health-care delivery, human resources, health-system infrastructure and supplies, clinical response, health-care management, and epidemiological surveillance. Results Policy types varied by health institution. The largest number of policies were aimed at public health responses followed by health-care delivery and human resources. Policies were mainly published during the community transmission phase. Conclusions The pandemic exposed underlying health-care system inequalities and a reactive rather than prepared response to the outbreak. Additionally, this study outlines potential policy gaps and delays in the response that could be avoided in the future

    Dinuclear pyridine-4-thiolate-bridged rhodium and iridium complexes as ditopic building blocks in molecular architecture

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    A series of dinuclear pyridine-4-thiolate (4-Spy)-bridged rhodium and iridium compounds [M(μ-4-Spy)(diolef)]2 [diolef = 1,5-cyclooctadiene (cod), M = Rh (1), Ir (2); diolef = 2,5-norbornadiene (nbd), M = Rh (3)] were prepared by the reaction of Li(4-Spy) with the appropriate compound [M(μ-Cl)(diolef)]2 (M = Rh, Ir). The dinuclear compound [Rh(μ-4-Spy)(CO)(PPh3)]2 (4) was obtained by the reaction of [Rh(acac)(CO)(PPh3)] (acac = acetylacetonate) with 4-pySH. Compounds 1-4 were assessed as metalloligands in self-assembly reactions with the cis-blocked acceptors [M(cod)(NCCH3)2](BF 4) [M = Rh (a), Ir (b)] and [M(H2O)2(dppp)] (OTf)2 [M = Pd (c), Pt (d); dppp = 1,3-bis(diphenylphosphino)propane] . The homometallic hexanuclear metallomacrocycles [{M2(μ-4-Spy) 2(cod)2}2{M(cod)}2](BF 4)2 (M = Rh [(1a)2], Ir [(2b)2]) and the heterometallic hexanuclear metallomacrocycles [{Rh2(μ-4-Spy) 2(cod)2}2{Ir(cod)}2](BF 4)2 [(1b)2], [{Rh2(μ-4-Spy) 2(cod)2}2{M′(dppp)}2](OTf) 4 (M′ = Pd [(1c)2], Pt [(1d)2]), and [{Ir2(μ-4-Spy)2(cod)2}2{M′ (dppp)}2](OTf)4 (M′ = Pd [(2c)2], Pt [(2d)2]) were obtained. NMR spectroscopy in combination with electrospray ionization mass spectrometry was used to elucidate the nature of the metalloligands and their respective supramolecular assemblies. Most of the synthesized species were found to be nonrigid in solution, and their fluxional behavior was studied by variable-temperature 1H NMR spectroscopy. An X-ray diffraction study of the assemblies (1a)2 and (1d)2 revealed the formation of rectangular (9.6 Å × 6.6 Å) hexanuclear metallomacrocycles with alternating dinuclear (Rh2) and mononuclear (Rh or Pt) corners. The hexanuclear core is supported by four pyridine-4-thiolate linkers, which are bonded through the thiolate moieties to the dinuclear rhodium units, exhibiting a bent-anti arrangement, and through the peripheral pyridinic nitrogen atoms to the mononuclear corners.Financial support for this work was provided by the Ministerio de Economía y Competitividad (MINECO/FEDER) of Spain (Projects CTQ2010-15221 and CTQ2012-31335), Diputación General de Aragón (Group E07), and Fondo Social Europeo.Peer Reviewe

    Clinical and economic impact of ‘ROS1-testing’ strategy compared to a ‘no-ROS1-testing’ strategy in advanced NSCLC in Spain

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    Background Detection of the ROS1 rearrangement is mandatory in patients with advanced or metastatic non-small cell lung cancer (NSCLC) to allow targeted therapy with specific inhibitors. However, in Spanish clinical practice ROS1 determination is not yet fully widespread. The aim of this study is to determine the clinical and economic impact of sequentially testing ROS1 in addition to EGFR and ALK in Spain. Methods A joint model (decision-tree and Markov model) was developed to determine the cost-effectiveness of testing ROS1 strategy versus a no-ROS1 testing strategy in Spain. Distribution of ROS1 techniques, rates of testing, positivity, and invalidity of biomarkers included in the analysis (EGFR, ALK, ROS1 and PD-L1) were based on expert opinion and Lungpath real-world database. Treatment allocation depending on the molecular testing results was defined by expert opinion. For each treatment, a 3-states Markov model was developed, where progression-free survival (PFS) and overall survival (OS) curves were parameterized using exponential extrapolations to model transition of patients among health states. Only medical direct costs were included (euro 2021). A lifetime horizon was considered and a discount rate of 3% was applied for both costs and effects. Both deterministic and probabilistic sensitivity analyses were performed to address uncertainty. Results A target population of 8755 patients with advanced NSCLC (non-squamous or never smokers squamous) entered the model. Over a lifetime horizon, the ROS1 testing scenario produced additional 157.5 life years and 121.3 quality-adjusted life years (QALYs) compared with no-ROS1 testing scenario. Total direct costs were increased up to euro 2,244,737 for ROS1 testing scenario. The incremental cost-utility ratio (ICUR) was 18,514 euro/QALY. Robustness of the base-case results were confirmed by the sensitivity analysis. Conclusions Our study shows that ROS1 testing in addition to EGFR and ALK is a cost-effective strategy compared to no-ROS1 testing, and it generates more than 120 QALYs in Spain over a lifetime horizon. Despite the low prevalence of ROS1 rearrangements in NSCLC patients, the clinical and economic consequences of ROS1 testing should encourage centers to test all advanced or metastatic NSCLC (non-squamous and never-smoker squamous) patients

    Clinical and economic impact of current ALK rearrangement testing in Spain compared with a hypothetical no-testing scenario

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    Background: Currently biomarkers play an essential role in diagnosis, treatment, and management of cancer. In non-small cell lung cancer (NSCLC) determination of biomarkers such as ALK, EGFR, ROS1 or PD-L1 is mandatory for an adequate treatment decision. The aim of this study is to determine the clinical and economic impact of current anaplastic lymphoma kinase testing scenario in Spain. Methods: A joint model, composed by decision-tree and Markov models, was developed to estimate the long-term health outcomes and costs of NSCLC patients, by comparing the current testing scenario for ALK in Spain vs a hypothetical no-testing. The current distribution of testing strategies for ALK determination and their sensitivity and specificity data were obtained from the literature. Treatment allocation based on the molecular testing result were defined by a panel of Spanish experts. To assess long-term effects of each treatment, 3-states Markov models were developed, where progression-free survival and overall survival curves were extrapolated using exponential models. Medical direct costs (expressed in €, 2019) were included. A lifetime horizon was used and a discount rate of 3% was applied for both costs and health effects. Several sensitivity analyses, both deterministic and probabilistic, were performed in order test the robustness of the analysis. Results: We estimated a target population of 7628 NSCLC patients, including those with non-squamous histology and those with squamous carcinomas who were never smokers. Over the lifetime horizon, the current ALK testing scenario produced additional 5060 and 3906 life-years and quality-adjusted life-years (QALY), respectively, compared with the no-testing scenario. Total direct costs were increased up to € 51,319,053 for testing scenario. The incremental cost-effectiveness ratio was 10,142 €/QALY. The sensitivity analyses carried out confirmed the robustness of the base-case results, being the treatment allocation and the test accuracy (sensitivity and specificity data) the key drivers of the model. Conclusions: ALK testing in advanced NSCLC patients, non-squamous and never-smoker squamous, provides more than 3000 QALYs in Spain over a lifetime horizon. Comparing this gain in health outcomes with the incremental costs, the resulting incremental cost-effectiveness ratio reinforces that testing non-squamous and never-smoker squamous NSCLC is a cost-effective strategy in Spain

    150 años del descubrimiento del yacimiento cámbrico de Murero (Cadenas Ibéricas, NE España).

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    The lower-middle Cambrian palaeontological site of Murero (Cadenas Ibéricas, NE Spain) is a classical locality of the Cambrian in Europe. The site was first reported by the French geologist Edouard de Verneuil in 1862, and now it achieves 150 years of geological works contributing to a better knowledge of the Cambrian Period. Murero is an exceptional Lagerstätte because the coexistence of both skeletal and soft-bodied groups along a continuous record of ca. 8 million years, which is subdivided into 14 trilobite zones. Murero was the first palaeontological site in Spain to obtain the highest protection figure (Bien de Interés Cultural, BIC) from the Spanish Administration in 1997. Since then, the educational and social projection of the site is continuously increasing

    Pyridinethiolate titanocene metalloligands and their self-assembly reactions to yield early-late metallamacrocycles

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    New titanocene pyridinethiolate compounds [(RCp)(2)Ti(4-Spy)(2)] (R = H (1), Me (2); Cp = cyclo-pentadienyl; 4-Spy = pyridine-4-thiolate) and [Cp2Ti(2-Spy)(2)] (3; 2-Spy = pyridine-2-thiolate) have been prepared by reaction of the corresponding Li(Spy) salt with the appropriate compound [(RCp)(2)TiCl2]. Compounds 1 and 2 have been used as metalloligands in self-assembly reactions with the acceptor late-transition-metal compounds [M(H2O)(2)(dppp)]-(OTf)(2) (M = Pd (a) Pt (b); dppp = 1,3-bis-(diphenylphosphino)propane), and the series of early-late tetranuclear metallamacrocycles [{(RCp)(2)Ti(4-Spy)(2)}{M-(dppp)}](2)(OTf)(4) (R = H, M = Pd (1(2)a(2)); R = H, M = Pt (1(2)b(2)); R = Me, M = Pd (2(2)a(2)); R = Me, M = Pt (2(2)b(2))) arising from the anti isomer of the titanocene metalloligands have been obtained. Only ligand transfer reactions from Ti to either Pd or Pt atoms have been observed when the pyridine-2-thiolate derivative 3 has been assayed in self-assembly processes. The obtained species have been characterized by NMR spectroscopy and ESI(+) mass spectrometry. The supramolecular assemblies have shown to be nonrigid in solution, and their fluxional behavior has been studied by VT H-1 NMR spectroscopy. A DFT study including ab initio molecular dynamics in order to elucidate the structures and the relative stability of the isomers has been performed
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