The Impact of Regiodefects on the Melt-Memory of Isotactic Polypropylene.

The memory of crystalline phase in the melt of isotactic polypropylene (iPP) in regiodefective samples of iPP characterized by different concentrations regiodefects, constituted by secondary 2,1 propene units, is studied. The self-nucleation (SN) experiments have demonstrated that the presence of 2,1 regiodefects produces a strong memory of the crystalline phase in the melt that persists up to temperatures much higher than the melting temperature. The extension of the heterogeneous melt (domain II) containing self-nuclei increases with increasing the concentration of regiodefects. The higher the concentration of regiodefects the higher the temperature at which the self-nuclei are dissolved and the homogeneous melt is achieved. This demonstrates that a strong memory of the crystalline phase of iPP in the melt exists not only in copolymers with noncrystallizable bulky comonomeric units rejected from the crystals but even when small defects are largely included in the crystals.

Combining Cyclic Units and Unsaturated Pendant Groups by Propene/1,5-Hexadiene Copolymerization Toward Functional Isotactic Polypropylene.

The precise use of a widely available and inexpensive metallocene catalyst enabled the synthesis of isotactic polypropylene copolymers characterized by the copresence of randomly distributed cyclic units in the backbone and unsaturated pendant units employing 1,5-hexadiene as comonomer. Optimization of the polymerization conditions avoided the cross-linking phenomena that negatively affects the material processing and final properties, resulting in good yields of samples featuring high molecular masses and a precisely controlled microstructure. Such polypropylene-based copolymers exhibit a broad spectrum of properties ranging from thermoplastic to surprising elastomeric behavior, with the additional value of being functionalizable by post-polymerization reactions.

Ethylene-alt-α-Olefin Copolymers by Hydrogenation of Highly Stereoregular cis-1,4 Polydienes: Synthesis and Structural Characterization.

The homogeneous non-catalytic hydrogenation of several types of iso- and syndiotactic cis-1,4 poly(1,3-diene)s with diimide, formed by thermal decomposition of p-toluene-sulfonyl-hydrazide, was examined. Perfectly alternating ethylene/1-alkene copolymers having different tacticity (i.e., isotactic and syndiotactic), which in some cases are difficult to synthesize by simple stereospecific co-polymerization of the corresponding monomers, were obtained. All the copolymers synthesized were fully characterized from a structural, morphological, and rheological point of view through different analytical techniques (FT-IR, NMR, GPC, DSC, RX).

Keto-Polyethylenes with Controlled Crystallinity and Materials Properties from Catalytic Ethylene-CO-Norbornene Terpolymerization.

Recent advances in Ni(II) catalyzed, nonalternating catalytic copolymerization of ethylene with carbon monoxide (CO) enable the synthesis of in-chain keto-functionalized polyethylenes (keto-PEs) with high-density polyethylene-like materials properties. Addition of norbornene as a bulky, noncrystallizable comonomer during catalytic polymerization allows tuning of the crystallinity in these keto-PE materials by randomly incorporated norbornene units in the polymer chain, while molecular weights are not adversely affected. Such crystallinity-reduced keto-PEs are characterized as softer materials with better ductility and may therefore be more suited for, e.g., potential film applications.

Mechanism of Alternating Poly(lactic-co-glycolic acid) Formation by Polymerization of (S)- and (R)-3-Methyl Glycolide Using an Enantiopure Aluminum Complex.

The mechanism(s) of alternating PLGA synthesis by ring-opening polymerization of (S)- and (R)-3-methyl glycolide promoted by enantiopure aluminum complexes have been rationalized by density functional theory (DFT) calculations. The high regioselectivity of the (S)-MeG polymerization is obtained by repetitive ring opening at the glycolyl site by the (R)-catalyst whereas a lower regioselectivity is predicted by the ROP of (R)-MeG. The behavior of the two monomers is rationalized by unveiling the active site fluxionality of the enantiopure catalyst, identifying the rate-limiting steps that encode a preference at the glycolyl site versus the lactyl site, and revealing selection of the opposite monomer enantioface. The microstructure of the PLGA copolymers is predicted by considering the influence of the configuration of the last inserted unit. The identification of the preferred mechanistic paths may allow for a targeted catalyst design to enhance control of the polymer microstructures.

Alta variabilidad en la determinación del Factor IX en muestras de plasma adicionadas con nonacog beta pegol entre distintos pares de reactivos/sistemas de detección / High variability in the determination of Factor IX in plasma samples spiked with nonacog beta pegol between different reagents/detection system pairs / Alta variabilidade na determinação do Fator IX em amostras de plasma enriquecidas com nonacog beta pegol entre diferentes pares de reagentes/ sistema de detecção

Resumen La hemofilia B es un trastorno hemorrágico hereditario, ligado al cromosoma X, que se caracteriza por el déficit del factor IX (FIX) de la coagulación. Para mejorar la calidad de vida de los pacientes y la adherencia al tratamiento se han desarrollado concentrados de factores recombinantes modificados para extender su vida media, denominados factores de vida media extendida (EHL: extended half life concentrates). El nonacog beta pegol (N9-GP) es una molécula de FIX humano recombinante glicopegilada que tiene una vida media de 93 h con una sola dosis y ha mostrado un porcentaje de recuperación mayor que otras moléculas. Para diagnosticar y monitorear el tratamiento del paciente hemofílico se determina la actividad del FIX con el ensayo coagulable en una etapa (OSA: one stage assay) y/o en el ensayo cromogénico. El objetivo de este trabajo, realizado en tres centros, fue medir la recuperación de N9-GP con 10 reactivos de APTT diferentes en tres plataformas, en muestras deficientes en FIX adicionadas in vitro con N9-GP, en cuatro niveles de concentración diferentes. Los resultados muestran una heterogeneidad en la actividad de N9-GP medidos por OSA con los diferentes reactivos de APTT cuando se realizaron las calibraciones con el estándar específico de cada coagulómetro. Se obtuvo un porcentaje de recuperación mayor de 92% con Cephascreen, Actin FSL y APTTest elágico en las tres plataformas evaluadas. Estos reactivos serían los únicos apropiados cuando se usa el OSA calibrado con plasma comercial para monitorear el tratamiento de los pacientes que reciben N9-GP.

Abstract Hemophilia B (HB) is an X-linked hereditary bleeding disorder characterised by coagulation factor IX (FIX) deficiency. To improve the quality of life of patients and adherence to treatment, recombinant factor concentrates glicomodified to extend their half-life have been developed. These are called extended half-life factors (EHL: extended half-life concentrates). Nonacog beta pegol (N9-GP) is a glycopegylated recombinant human FIX molecule that has a half-life of 93 h with a single dose and has shown a higher recovery percentage than other molecules. For diagnosis and monitoring the treatment of hemophiliac patients, FIX activity is determined with the One Stage Clotting Assay (OSA) and/or the chromogenic assay. The objective of this work, carried out in three centres, was to measure the recovery of N9-GP with 10 different APTT reagents on three platforms, in FIX deficient samples spiked in vitro with N9-GP, at four different concentration levels. The results show a heterogeneity in the activity of N9-GP measured by OSA with the different APTT reagents when the calibrations were performed with the specific standard of each coagulometer. A recovery percentage greater than 92% was obtained with Cephascreen, Actin FSL and APTTest ellagic in the three platforms evaluated. These reagents would be the only ones appropriate when using the commercial plasma-calibrated OSA to monitor the treatment of patients treated with N9-GP.

Resumo A hemofilia B é uma doença hemorrágica hereditária ligada ao cromossomo X caracterizada pela deficiência do fator de coagulação IX (FIX). Para melhorar a qualidade de vida dos pacientes e a adesão ao tratamento, foram desenvolvidos concentrados de fatores recombinantes modificados para prolongar sua meia-vida, chamados de fatores de meia-vida estendida (EHL: extended half life concentrates). Nonacog beta pegol (N9-GP) é uma molécula de FIX humano recombinante glicopeguilada que tem meia-vida de 93 h com uma dose única e mostrou uma porcentagem de recuperação maior do que outras moléculas. Para diagnosticar e monitorar o tratamento de pacientes hemofílicos, a atividade do FIX é determinada com o ensaio coagulável em um estágio (OSA: One Stage Assay) e/ou o ensaio cromogênico. O objetivo deste trabalho, realizado em três centros, foi medir a recuperação de N9-GP com 10 reagentes de APTT diferentes em três plataformas, em amostras deficiente de fator IX adicionadas in vitro com N9-GP, em quatro níveis de concentração diferentes. Os resultados mostram uma heterogeneidade na atividade de N9-GP medidos por OSA com os diferentes reagentes de APTT quando as calibragens foram realizadas com o padrão específico de cada coagulômetro. Uma porcentagem de recuperação superior a 92% foi obtida com Cephascreen, Actin FSL e APTTest elágico nas três plataformas avaliadas. Esses reagentes seriam os únicos apropriados ao usar o OSA calibrado com plasma comercial para monitorar o tratamento de pacientes tratados com N9-GP.

Leisure-time physical activity and its relationship with gender and walkingtime to the park or gym / Atividade física de lazer e seu relacionamento com gênero e tempo de caminhada até o parque ou academia

In this cross-sectional study, we describe the leisure-time physical activity (LTPA) of 374 adults who answered an online questionnaire. We also explored the relationship between LTPA, gender, and walking time to the nearest park or gym from the participant's residence. As expected from a recruitment process prone to include physically active individuals, the prevalence of LTPA during the last week was 80.2% (CI95%: 75.8 -84.1). Our median participant reported having performed 280 (CI95%: 240 ­340) minutes of LTPA during the last week. The prevalence of LTPA and the duration of light and total LTPA were similar between men and women. However, in our sample, women practiced more moderate LTPA and men more vigorous LTPA. The relationship between LTPA and walking time distance to the nearest park or gym is not linear, meaning that living closer to parks or gyms does not necessarily imply more LTPA.

Neste estudo transversal, descrevemos a atividade física no lazer (AFL) de 374 adultos que responderam a um questionário online. Também exploramos a relação entre AFL, gênero e tempo de caminhada até o parque ou academia mais próximo da residência do participante. Como esperado de um recrutamento propenso a incluir indivíduos fisicamente ativos, a prevalência de AFL na última semana foi de 80,2% (IC95%: 75,8 - 84,1). Nosso participante mediano relatou ter realizado 280 (IC95%: 240 ­ 340) minutos de AFL na última semana. A prevalência de AFL e a duração da AFL leve e total foram semelhantes entre homens e mulheres. No entanto, em nossa amostra, as mulheres praticaram mais AFL moderadas e os homens AFL vigorosas. A relação entre AFL e distância de caminhada até o parque ou academia mais próxima não é linear, indicando que morar mais perto de parques ou academias não implica necessariamente em mais AFL.

Crystallization Behavior of Isotactic Propene-Octene Random Copolymers.

The crystallization behavior of random propene-octene isotactic copolymers (iPPC8) prepared with a homogeneous metallocene catalyst has been studied. Samples of iPPC8 with low octene content up to about 7 mol% were isothermally crystallized from the melt at various crystallization temperatures. The samples crystallize in mixtures of the α and γ forms of isotactic polypropylene (iPP). The relative amount of γ form increases with increasing crystallization temperature, and a maximum amount of γ form (fγ(max)) is achieved for each sample. The crystallization behavior of iPPC8 copolymers is compared with the crystallization from the melt of propene-ethylene, propene-butene, propene-pentene, and propene-hexene copolymers. The results show that the behavior of iPPC8 copolymers is completely different from those described in the literature for the other copolymers of iPP. In fact, the maximum amount of γ form achieved in samples of different copolymers of iPP generally increases with increasing comonomer content, while in iPPC8 copolymers the maximum amount of γ form decreases with increasing octene content. The different behaviors are discussed based on the inclusion of co-monomeric units in the crystals of α and γ forms of iPP or their exclusion from the crystals. In iPPC8 copolymers, octene units are excluded from the crystals giving only the interruption effect that shortens the length of regular propene sequences, inducing crystallization of the γ form at low octene concentrations, lower than 2 mol%. At higher octene concentration, the crystallization of the kinetically favored α form prevails.

Melt-Crystallizations of α and γ Forms of Isotactic Polypropylene in Propene-Butene Copolymers.

Random isotactic propene-butene copolymers (iPPC4) of different stereoregularity have been synthesized with three different homogeneous single center metallocene catalysts having different stereoselectivity. All samples crystallize from the polymerization solution in mixtures of α and γ forms, and the relative amount of γ form increases with increasing concentrations of butene and of rr stereodefects. All samples crystallize from the melt in mixtures of α and γ forms and the fraction of γ form increases with decreasing cooling rate. At high cooling rates, the crystallization of the α form is always favored, even for samples that contain high total concentration of defects that should crystallize in the γ form. The results demonstrate that in iPPs containing significant concentrations of defects, such as stereodefects and comonomeric units, the γ form is the thermodynamically stable form of iPP and crystallizes in selective conditions of very slow crystallization, whereas the α form is the kinetically favored form and crystallizes in conditions of fast crystallization.

Structure and Morphology of Crystalline Syndiotactic Polypropylene-Polyethylene Block Copolymers.

A study of the structure and morphology of diblock copolymers composed of crystallizable blocks of polyethylene (PE) and syndiotactic polypropylene (sPP) having different lengths is reported. In both analyzed samples, the PE block crystallizes first by cooling from the melt (at 130 °C) and the sPP block crystallizes after at a lower temperature. Small angle X-ray scattering (SAXS) recorded during cooling showed three correlation peaks at values of the scattering vector, q1 = 0.12 nm-1, q2 = 0.24 nm-1 and q3 = 0.4 nm-1, indicating development of a lamellar morphology, where lamellar domains of PE and sPP alternate, each domain containing stacks of crystalline lamellae of PE or sPP sandwiched by their own amorphous phase of PE or sPP. At temperatures higher than 120 °C, when only PE crystals are formed, the morphology is defined by the formation of stacks of PE lamellae (17 nm thick) alternating with amorphous layers and with a long period of nearly 52 nm. At lower temperatures, when crystals of sPP are also well-formed, the morphology is more complex. A model of the morphology at room temperature is proposed based on the correlation distances determined from the self-correlation functions extracted from the SAXS data. Lamellar domains of PE (41.5 nm thick) and sPP (8.2 nm thick) alternate, each domain containing stacks of crystalline lamellae sandwiched by their own amorphous phase, forming a global morphology having a total lamellar periodicity of 49.7 nm, characterized by alternating amorphous and crystalline layers, where the crystalline layers are alternatively made of stacks of PE lamellae (22 nm thick) and thinner sPP lamellae (only 3.5 nm thick).

Recomendaciones de manejo de los anticoagulantes orales directos (DOACs) anti Xa y anti IIa / Recommendations for the practical management of the direct oral anticoagulants anti Xa and anti IIa

Resumen Los anticoagulantes orales directos han surgido como una de las herramientas que ha cambiado el manejo de la enfermedad trombótica en los últimos 15 años. Sus ventajas, desde el punto de vista de la facilidad de uso y menor riesgo de sangrado, especialmente de sangrado cerebral, han posicionado a estos nuevos anticoagulantes como la primera alternativa de tratamiento en las dos indicaciones más frecuentes en que necesitamos estas drogas, la fibrilación auricular y la enfermedad tromboembólica venosa. Sin embargo, no todos los pacientes pueden recibir estos agentes, no todos los anticoagulantes directos tienen las mismas pro piedades y fundamentalmente, no todas las enfermedades con indicación de un anticoagulante pueden tratarse con ellos;con lo cual es necesario que todos los profesionales que están involucrados en el manejo de estos medicamentos estén obligados a conocerlos en profundidad, para poder decidir el mejor tratamiento en cada caso particular. Este documento de posición de expertos de diferentes especialidades de Argentina, presenta lineamientos para el uso correcto de los anticoagulantes directos en base a nueva evidencia y a la experiencia de uso de un amplio grupo de profesionales. La forma de relacionarnos con el tratamiento anticoagulante ha cambiado. Los médicos que trabajamos con ellos también debemos hacerlo.

Abstract Direct oral anticoagulants have emerged as the drugs that have changed the man agement of the antithrombotic treatment in the last 15 years. Their advantages, like a more friendly way of anticoagulation and their lower risk of bleeding, especially in the brain, have positioned these new anticoagu lants as the first drug of choice in the two most frequent indications of anticoagulation, atrial fibrillation, and the venous thromboembolic disease. However, not all the patients can receive these agents, not all the direct oral anticoagulants have the same characteristics, and most importantly, not all the diseases with an indication of an anticoagulant drug can be treated with them. Therefore, it is mandatory that all the faculties involved in the management of these drugs must know them in depth, to decide the best treatment for the patient. This position paper, from a group of experts in anticoagulation in Argentina, can help the general practitioner in the daily use of direct oral anticoagulants based on the new evidence and the experience of a wide group of professionals. The way we relate to the anticoagulant treatment has changed in the last years. The doctors who work with them must also do so.

Método experimental e ensaios clínicos: metassíntese de artigos de revisão publicados em português: [errata] / Experimental method and clinical trials: metassynthesis of review articles publishedin portuguese: [errata] / Método experimental y ensayos clínicos: metasíntesis de artículos de revisión publicados en portugués: [errata]

O método experimental (ME) envolve um conjunto de procedimentos que podem ser utilizados por várias ciências para responder questões de pesquisa, refutar ou corroborar hipóteses. No presente trabalho, conduzimos uma revisão sistemática de artigos de revisão publicados em português que tiveram como foco explicar o ME. Utilizamos as bases de dados SciELO e Google Acadêmico, sem restringir a data de publicação dos artigos. Incluímos 64 artigos após a aplicação dos critérios de elegibilidade. Por meio da análise de conteúdo, sintetizamos informações desses artigos que favorecem a condução de estudos experimentais e a avaliação crítica de seus métodos. Adicionalmente, apontamos lacunas como a carência de artigos sobre estatística aplicada ao ME e uso de técnicas qualitativas.

The experimental method (EM) involves a set of procedures that can be used by different sciences to answer research questions, refute or corroborate hypotheses. In the present work, we conducted a systematic review of review articles published in Portuguese that focused on explaining the EM. We use the SciELO and Google Scholar databases, without restricting the articles publication date. We included 64 articles after applying the eligibility criteria. Using content analysis, we synthesized information from these articles that favor the conduction of experimental studies and the critical evaluation of their methods. Additionally, we point out gaps such as the lack of papers on statistics applied to the EM and the use of qualitative techniques.

El método experimental (ME) implica un conjunto de procedimientos que pueden ser utilizados por diferentes ciencias para responder preguntas de investigación, refutar o corroborar hipótesis. En el presente trabajo, realizamos una revisión sistemática de artículos de revisión publicados en portugués que se centraron en explicar el ME. Utilizamos las bases de datos SciELO y Google Académico, sin restringir la fecha de publicación de los artículos. Incluimos 64 artículos después de aplicar los criterios de elegibilidad. Mediante el análisis de contenido, sintetizamos información de estos artículos que favorecen la realización de estudios experimentales y la evaluación crítica de sus métodos. Además, señalamos lagunas, como la carencia de artículos sobre estadísticas aplicadas a él ME y el uso de técnicas cualitativas.

Temáticas, reporte e métodos de revisões sistemáticas brasileiras sobre exergames: uma revisão guarda-chuva / Topics, report and methods of brazilian systematic reviews about exergames: an umbrella review

Exergames são jogos virtuais que funcionam por meio de movimentos corporais e aumentam o gasto energético significativamente em comparação ao repouso. No presente estudo, analiso as temáticas, reporte e métodos de revisões sistemáticas (RSs) brasileiras sobre exergames. Por meio de uma revisão guarda-chuva (revisão de RSs) selecionei 16 estudos que atenderam critérios de elegibilidade pré-estabelecidos. Analisei o conteúdo das RSs para mapear suas temáticas e utilizei a ferramenta AMSTAR 2 para avaliar seus métodos e reporte. Exergames foram relacionados a diversos temas (p.ex., dispêndio energético, reabilitação, ensino e aprendizagem) e nenhuma RS abordou a mesma questão de pesquisa. Infelizmente, todas as RSs apresentaram limitações no reporte e métodos. Essas limitações dificultam a avaliação dessas RSs e diminuem a confiança nas conclusões alcançadas por seus autores.

Exergames are virtual games that work through body movements and increase energy expenditure significantly in comparison to rest. In the present study, I analyze the topics, study's report, and methods of Brazilian systematic reviews (SRs) about exergames. Through an umbrella review (review of SRs), I selected 16 studies that met pre-established eligibility criteria. I analyzed the contents of these SRs to map their topics and used the AMSTAR 2 tool to evaluate their methods and report. Exergames were related to several themes (e.g. energy expenditure, rehabilitation, teaching, and learning), and no SR addressed the same research question. Unfortunately, all SRs have limitations in their report and methods. These limitations hinder the evaluation of these SRs and decrease the confidence in the conclusions reached by their authors.

Double Crystallization and Phase Separation in Polyethylene-Syndiotactic Polypropylene Di-Block Copolymers.

Crystallization and phase separation in the melt in semicrystalline block copolymers (BCPs) compete in defining the final solid state structure and morphology. In crystalline-crystalline di-block copolymers the sequence of crystallization of the two blocks plays a definitive role. In this work we show that the use of epitaxial crystallization on selected crystalline substrates allows achieving of a control over the crystallization of the blocks by inducing crystal orientations of the different crystalline phases and a final control over the global morphology. A sample of polyethylene-block-syndiotactic polypropylene (PE-b-sPP) block copolymers has been synthesized with a stereoselective living organometallic catalyst and epitaxially crystallized onto crystals of two different crystalline substrates, p-terphenyl (3Ph) and benzoic acid (BA). The epitaxial crystallization on both substrates produces formation of highly ordered morphologies with crystalline lamellae of sPP and PE highly oriented along one direction. However, the epitaxial crystallization onto 3Ph should generate a single orientation of sPP crystalline lamellae highly aligned along one direction and a double orientation of PE lamellae, whereas BA crystals should induce high orientation of only PE crystalline lamellae. Thanks to the use of the two selective substrates, the final morphology reveals the sequence of crystallization events during cooling from the melt and what is the dominant event that drives the final morphology. The observed single orientation of both crystalline PE and sPP phases on both substrates, indeed, indicates that sPP crystallizes first onto 3Ph defining the overall morphology and PE crystallizes after sPP in the confined interlamellar sPP regions. Instead, PE crystallizes first onto BA defining the overall morphology and sPP crystallizes after PE in the confined interlamellar PE regions. This allows for discriminating between the different crystalline phases and defining the final morphology, which depends on which polymer block crystallizes first on the substrate. This work also shows that the use of epitaxial crystallization and the choice of suitable substrate offer a means to produce oriented nanostructures and morphologies of block copolymers depending on the composition and the substrates.

Método experimental e ensaios clínicos: metassíntese de artigos de revisão publicados em português / Experimental method and clinical trials: metassynthesis of review articles publishedin portuguese / Método experimental y ensayos clínicos: metasíntesis de artículos de revisión publicados en portugués

O método experimental (ME) envolve um conjunto de procedimentos que podem ser utilizados por várias ciências para responder questões de pesquisa, refutar ou corroborar hipóteses. No presente trabalho, conduzimos uma revisão sistemática de artigos de revisão publicados em português que tiveram como foco explicar o ME. Utilizamos as bases de dados SciELO e Google Acadêmico, sem restringir a data de publicação dos artigos. Incluímos 64 artigos após a aplicação dos critérios de elegibilidade. Por meio da análise de conteúdo, sintetizamos informações desses artigos que favorecem a condução de estudos experimentais e a avaliação crítica de seus métodos. Adicionalmente, apontamos lacunas como a carência de artigos sobre estatística aplicada ao ME e uso de técnicas qualitativas.

The experimental method (EM) involves a set of procedures that can be used by different sciences to answer research questions, refute or corroborate hypotheses. In the present work, we conducted a systematic review of review articles published in Portuguese that focused on explaining the EM. We use the SciELO and Google Scholar databases, without restricting the articles publication date. We included 64 articles after applying the eligibility criteria. Using content analysis, we synthesized information from these articles that favor the conduction of experimental studies and the critical evaluation of their methods. Additionally, we point out gaps such as the lack of papers on statistics applied to the EM and the use of qualitative techniques.

El método experimental (ME) implica un conjunto de procedimientos que pueden ser utilizados por diferentes ciencias para responder preguntas de investigación, refutar o corroborar hipótesis. En el presente trabajo, realizamos una revisión sistemática de artículos de revisión publicados en portugués que se centraron en explicar el ME. Utilizamos las bases de datos SciELO y Google Académico, sin restringir la fecha de publicación de los artículos. Incluimos 64 artículos después de aplicar los criterios de elegibilidad. Mediante el análisis de contenido, sintetizamos información de estos artículos que favorecen la realización de estudios experimentales y la evaluación crítica de sus métodos. Además, señalamos lagunas, como la carencia de artículos sobre estadísticas aplicadas a él ME y el uso de técnicas cualitativas.

Consenso argentino en gestión efectiva de clínicas de anticoagulación para uso de antagonistas de la vitamina K / Argentine consensus in effective management of anticoagulation clinics for the use of vitamin K antagonists

Resumen El tratamiento de un paciente anticoagulado con antagonistas de la vitamina K (AVK) sigue siendo un desafío, especialmente en regiones donde, por el costo, los dicumarínicos son todavía la alternativa más buscada a la hora de elegir un anticoagulante oral. Las clínicas de anticoagulación han demostrado ser la forma más eficiente y segura de evitar complicaciones trombóticas y hemorrágicas y de mantener al paciente en rango óptimo de tratamiento. Sin embargo, requieren de una adecuada infraestructura y personal capacitado para que funcionen eficientemente. En este consenso argentino se propone una serie de parámetros para la gestión efectiva de una clínica de anticoagulación. El objetivo es lograr una elevada calidad desde el punto de vista clínico-asistencial a través de un laboratorio de hemostasia de excelencia. Los criterios desarrollados en el documento fueron consensuados por un amplio grupo de expertos especialistas en hematología y en bioquímica de todo el país. Estos criterios deben adaptarse a la irregular disponibilidad de recursos de cada centro, pero siempre se los debe tener en cuenta a la hora de indicar el tratamiento anticoagulante con estas drogas. Tener en consideración estas premisas nos permitirá optimizar la atención del enfermo anticoagulado con AVK y de esta forma minimizar las intercurrencias trombóticas y hemorrágicas a las que está expuesto, para así honrar nuestra promesa de no dañar al paciente.

Abstract Treating an anticoagulated patient with vitamin K antagonists (VKA) remains a challenge, especially in areas where dicoumarins are still the first drug of choice due to the cost of other oral anticoagulants. Anticoagulation clinics have proven to be the most efficient and safe way to avoid thrombotic and hemorrhagic complications and to keep patients in optimal treatment range. However, they require adequate infrastructure and trained personnel to work properly. In this Argentine consensus we propose a series of guidelines for the effective management of the anticoagulation clinics. The goal is to achieve the excellence in both the clinical healthcare and the hemostasis laboratory for the anticoagulated patient. The criteria developed in the document were agreed upon by a large group of expert specialists in hematology and biochemistry from all over the country. The criteria presented here must always be considered when indicating VKA although they had to be adapted to the unequal reality of each center. Taking these premises into consideration will allow us to optimize the management of the anticoagulated patient with VKA and thus minimize thrombotic and hemorrhagic intercurrences, in order to honor our promise not to harm the patient.

Ethylene-co-norbornene Copolymerization Using a Dual Catalyst System in the Presence of a Chain Transfer Agent.

Ethylene-co-norbornene copolymers were synthesized by a dual catalyst system at three concentrations of norbornene in the feed and variable amounts of ZnEt2, as a possible chain transfer agent. The dual catalyst system consists of two ansa-metallocenes, isopropyliden(η5-cyclopentadienyl)(η5-indenyl)zirconium dichloride (1) and isopropyliden(η5-3-methylcyclopentadienyl)(η5-fluorenyl)zirconium dichloride (2), activated with dimethylanilinium tetrakis(pentafluorophenyl)borate, in presence of TIBA. Values of norbornene content, molecular mass, glass transition temperature, and reactivity ratios r11 and r21 of copolymers prepared in the presence of 1+2 are intermediate between those of reference copolymers. The study of tensile and elastic properties of ethylene-co-norbornene copolymers (poly(E-co-N)s) gave evidence that copolymers were obtained in part through transfer of polymer chains between different transition metal sites. Mechanical properties are clearly different from those expected from a blend of the parent samples and reveal that copolymers obtained in the presence of 1+2 and ZnEt2 consist of a reactor blend of segmented chains produced by exchange from 2 to 1 and 1 to 2 acting as the ideal compatibilizer of chains produced by the chain transfer from 1 to 1, and from 2 to 2.

Time-Resolving Study of Stress-Induced Transformations of Isotactic Polypropylene through Wide Angle X-ray Scattering Measurements.

The development of a highly oriented fiber morphology by effect of tensile deformation of stereodefective isotactic polypropylene (iPP) samples, starting from the unoriented γ form, is studied by following the transformation in real time during stretching through wide angle X-ray scattering (WAXS) measurements. In the stretching process, after yielding, the initial γ form transforms into the mesomorphic form of iPP through mechanical melting and re-crystallization. The analysis of the scattering invariant measured in the WAXS region highlights that the size of the mesomorphic domains included in the well oriented fiber morphology obtained at high deformations increases through a process which involves the coalescence of the small fragments formed by effect of tensile stress during lamellar destruction with the domain of higher dimensions.

Isotactic and Syndiotactic Alternating Ethylene/Propylene Copolymers Obtained Through Non-Catalytic Hydrogenation of Highly Stereoregular cis-1,4 Poly(1,3-diene)s.

The homogeneous non-catalytic hydrogenation of cis-1,4 poly(isoprene), isotactic cis-1,4 poly(1,3-pentadiene) and syndiotactic cis-1,4 poly(1,3-pentadiene) with diimide, formed by thermal decomposition of para-toluenesulfonylhydrazide, is examined. Perfectly alternating ethylene/propylene copolymers having different tacticity (i.e., isotactic and syndiotactic), which are difficult to synthesize by stereospecific copolymerization of the corresponding monomers, are obtained. Both isotactic and syndiotactic alternating ethylene/propylene copolymers are amorphous, with very low glass transition temperatures.

The influence of subcutaneous fat in the skin temperature variation rate during exercise

Introduction: Thermography records the skin temperature, which can be influenced by: muscle mass and subcutaneous fat layer. Thus, the aim of this study was to investigate the influence of subcutaneous fat layer in the skin temperature variation rate, during exercise. Methods This is a short-longitudinal study that involved 17 healthy male trained volunteers. Volunteers were divided in two groups. The first called GP1 with nine volunteers (biceps brachii skinfold thickness < 4 mm) and the second called GP2 with eight volunteers (biceps brachii skinfold thickness from 4 to 8 mm). Both groups performed three sets with 16 repetitions of unilateral biceps brachii bi-set exercise with dominant arm (eight repetitions of biceps curls and another eight of biceps hammer curls, with dumbbells), and with load of 70% of 1RM. The rest time between sets was 90s. Results The skin temperature variation rate (variation of temperature / time) was 3.59 × 10-3 ± 1.47 × 10-3 °C/s for GP1 and 0.66 × 10-3 ± 4.83 × 10-3 °C/s for GP2 (p = 0.138) considering all moments. For the period after set 1 until the end of set 3, skin temperature variation rate was 5.11 × 10-3 ± 2.57 × 10-3 °C/s for GP1 and 1.88 × 10-3 ± 3.60 × 10-3 °C/s for GP2 (p = 0.048). Subcutaneous fat layer also influences the skin temperature at resting (p = 0.044). Conclusion Subjects with lower subcutaneous fat layer have a higher skin temperature variation rate during exercise than those with higher subcutaneous fat layer.