Nuevo método de valoración de ácido ascórbico en vegetales frescos

Se describe un método colorimétrico de valoración de ácido ascórbico empleando una solución de reactivo de Tillmans en xileno de cuyodisolvente se arrastra el Tillmans por una solución acuosa de fosfato; la solución azul obtenida se lleva por adición de una solución tampón a un pH próximo a 4, se adiciona el extracto que debe valorarse y transcurrido el tiempo de reacción se agita la pequena probeta que contiene las soluciones y reactivos anteriores, revertiendo el Tillmans sobrante al xileno inicial. La pérdida de D. O. de la solución permite hallar el contenido en ácido ascórbico del volumen o peso de muestra empleados.Son ventajas del método el reducir las medidas de xileno y Tillmans a una sola, la fijación cómoda y irgurosa del tiempo al no tener que adicionar reactivo alguno después de la medida del extracto y la estabilidad de la solución de Tillmans en xileno

Precise 210Pb determination with high-efficiency gamma spectrometry for dating of marine sedimentary cores

[EN]In order to establish the chronology of deep-sea sediments from high-resolution 210Pb-dating, the determination of 210Pb and 226Ra activity concentrations needs to be improved. Gamma spectrometry allows determining simultaneously both radionuclides. However, spectrum background is still an issue to obtain high sensitivity. Four deep-sea sediment cores were dated using Mazinger, a gamma spectrometer with high-efficiency and very low-background, and the Constant Rate and Supply model was applied to obtain recent age

The FXII c.-4T > C Polymorphism as a Disease Modifier in Patients With Hereditary Angioedema Due to the FXII p.Thr328Lys Variant

Background: Hereditary angioedema due to the Thr328Lys variant in the coagulation factor XII (HAE-FXII) affects mainly women in whom the symptomatology is dependent on high estrogen levels. Clinical variability and incomplete penetrance are challenging features that hinder the diagnosis and management of HAE-FXII. The c.-4T>C Kozak polymorphism is the only common variation accounting for FXII plasma levels and was previously shown to modify the course of HAE due to C1-Inhibitor deficiency. Objectives: To assess the influence of the c.-4T>C polymorphism on disease expression in 39 Spanish HAE-FXII index patients. Methods: The c.-4T>C polymorphism was sequenced by the standard Sanger method, and HAE severity was calculated according to the score by Cumming et al. (2003) The activation of the contact system was quantified by the kallikrein-like activity of plasma in chromogenic assays upon activation with high-molecular-weight dextran sulfate. Results: The c.-4CC genotype was overrepresented in the studied cohort: 82% were CC-homozygous (expected frequency = 59%) and 18% were CT-heterozygous (expected frequency = 39%) (p = 0.001). Patients with a c.-4CC genotype exhibited higher kallikrein-like activity (0.9659 +/- 0.1136) than those with a c.-4TC genotype (0.7645 +/- 0.1235) (p = 0.024) or healthy donors. Moreover, the polymorphism influenced HAE-FXII severity score (c.-4CC = 4.43 +/- 2.28 vs c.-4TC = 2.0 +/- 1.15; p = 0.006) but not the degree of estrogen dependence or time until remission. Conclusion: The c.-4T>C polymorphism is overrepresented in a Spanish HAE-FXII cohort and significantly influences the degree of contact system activation and the clinical severity of the disease

Uncontrolled Donation after Circulatory Death: European practices and recommendations for the development and optimization of an effective programme.

Shortage of organs has made a global interest for donation after circulatory death (DCD) to re-emerge. While controlled DCD (cDCD) has been progressively increasing, uncontrolled DCD (uDCD) has only been developed in a few settings.1 This activity is quantitatively important in France and Spain, although it has also been reported in other European countries, as Austria, Belgium, Italy, the Netherlands, and recently in Russia.2,3 uDCD protocols have allowed the transplantation of a significant number of kidneys, livers and lungs at these countries.3 Excellent graft survival has been reported in kidney transplantation from uDCD, in spite of an increased incidence of delayed graft function (DGF).4,5,6,7,8,9,10,11,12,13,14,1516 Albeit promising, results with liver transplants obtained in uDCD protocols do not consistently provide similar outcomes compared with livers from donors after brain death (DBD), mainly due to a higher incidence of primary graft dysfunction and non-function and biliary complications.17,18,19,20,21,22 Lung transplantation is still facing limited experience, but preliminary results are encouraging.pre-print938 K

Analysis of incidence, risk factors and clinical outcome of thromboembolic and bleeding events in 431 allogeneic hematopoietic stem cell transplantation recipients

This is an open-access paper.-- et al.Allogeneic hematopoietic stem cell transplantation recipients have an increasing risk of both hemorrhagic and thrombotic complications. However, the competing risks of two of these life-threatening complications in these complex patients have still not been well defined. We retrospectively analyzed data from 431 allogeneic transplantation recipients to identify the incidence, risk factors and mortality due to thrombosis and bleeding. Significant clinical bleeding was more frequent than symptomatic thrombosis. The cumulative incidence of a bleeding episode was 30.2% at 14 years. The cumulative incidence of a venous or arterial thrombosis at 14 years was 11.8% and 4.1%, respectively. The analysis of competing factors for venous thrombosis revealed extensive chronic graft-versus-host disease to be the only independent prognostic risk factor. By contrast, six factors were associated with an increased risk of bleeding; advanced disease, ablative conditioning regimen, umbilical cord blood transplantation, anticoagulation, acute III-IV graft-versus-host disease, and transplant-associated microangiopathy. The development of thrombosis did not significantly affect overall survival (P=0.856). However, significant clinical bleeding was associated with inferior survival (P<0.001). In allogeneic hematopoietic stem cell transplantation, significant clinical bleeding is more common than thrombotic complications and affects survival.Peer Reviewe

Coordination of Cell Differentiation and Migration in Mathematical Models of Caudal Embryonic Axis Extension

Vertebrate embryos display a predominant head-to-tail body axis whose formation is associated with the progressive development of post-cranial structures from a pool of caudal undifferentiated cells. This involves the maintenance of active FGF signaling in this caudal region as a consequence of the restricted production of the secreted factor FGF8. FGF8 is transcribed specifically in the caudal precursor region and is down-regulated as cells differentiate and the embryo extends caudally. We are interested in understanding the progressive down-regulation of FGF8 and its coordination with the caudal movement of cells which is also known to be FGF-signaling dependent. Our study is performed using mathematical modeling and computer simulations. We use an individual-based hybrid model as well as a caricature continuous model for the simulation of experimental observations (ours and those known from the literature) in order to examine possible mechanisms that drive differentiation and cell movement during the axis elongation. Using these models we have identified a possible gene regulatory network involving self-repression of a caudal morphogen coupled to directional domain movement that may account for progressive down-regulation of FGF8 and conservation of the FGF8 domain of expression. Furthermore, we have shown that chemotaxis driven by molecules, such as FGF8 secreted in the stem zone, could underlie the migration of the caudal precursor zone and, therefore, embryonic axis extension. These mechanisms may also be at play in other developmental processes displaying a similar mode of axis extension coupled to cell differentiation

CUIDADOS ENFERMEROS EN LA UNIDAD DE REANIMACIÓN POSTANESTÉSICA A PACIENTES SOMETIDOS A CIRUGÍA HIPOFISARIA POR VÍA TRANSESFENOIDAL.

Introduction: The patients with hypophyseal tumors given to transsphenoidal hypophysectomy (T.H.) can present multiple endocrine disorders and develop specific complications inherent in the surgical technology, together with hormonal alterations due to the manipulation of the gland. These alterations usually appear in the first 24 hours of postoperative period during their stay in the Post Anesthetia Care Unit (P.A.C.U.). Objectives: To unify nursing performance criteria. To elaborate a standardized care programme. To monitor and detect in advance potential complications in the immediate postoperative period of the patients given to hypophyseal surgery transsphenoidally, admitted to our unit. Methodology: We carried out a study on 30 patients operated on T.H. in our Hospital in the last two years, checking the first 24 hours of the postoperative period and collecting the following parameters: Haemodynamic Data (T.A., F.C., P.V.C., T ª); Hourly Diuresis, analytical data (Hb., Htco., ions, osmolaridad, acid – base balance); Water balance, complications and postoperative treatment. A program about standardized cares based on the P.A.C.U. nursing professionals experience was carried out following the taxonomy of N.A.N.D.A., N.I.C. and N.O.C. Results: The average age of the patients was over 37 +/-15 years old. The monitoring consisted of E.C.G., Sat. O2, arterial tension, P.V.C., T ª and hourly diuresis in all cases. The most frequent complication detected was the diabetes insipidus in 70% of the cases; other complications were nauseas, vomits in 20% and arterial hypertension in 15%. Conclusions: By means of the application of the programme of standardized cares in the patients given to hypophyseal surgery transsphenoidally, the care quality has been improved. As well as a quick control of the postoperative complications has been detected. The patient stay in the P.A.C.U. has been shortened and the beginning of an early treatment of the diabetes insipidus has been facilitated.Introducción: Los enfermos con tumores hipofisiarios sometidos a hipofisectomía transesfeinoidal (h:t.) pueden presentar trastornos endocrinos múltiples y desarrollan complicaciones específicas inherentes a la técnica quirúrgica, junto a alteraciones hormonales por manipulación de la glándula que suelen aparecer en las primeras 24 h. del postoperatorio durante su estancia en la U.R.P.A. Objetivos: Unificar criterios de actuación de enfermería. Elaborar plan de cuidados estandarizados. Vigilar y detectar precozmente las posibles complicaciones en el postoperatorio inmediato de los pacientes sometidos a una intervención hipofisaria por vía transesfenoidal ingresados en nuestra unidad. Metodología: Realizamos un estudio sobre 30 pacientes intervenidos de h.t. en los dos últimos años en nuestro hospital, revisando las primeras 24h. del postoperatorio y recogiendo los siguientes parámetros: datos hemodinámicos (t.a., f.c., p.v.c., tª). Diuresis horaria, datos analíticos (hb., htco., iones, osmolaridad, equilibrio ácido-base). Balance hídrico complicaciones y tratamiento postoperatorio. Se realizó un plan de cuidados estandarizado basado en la experiencia de los profesionales de enfermería de la U.R.P.A., para ello se eligió la taxonomía de la N.A.N.D.A., N.I.C. Y N.O.C. Resultados: La edad media de los pacientes fue de 37 +_ 15 a. La monitorización consistió en todos los casos en e.c.g., sat.o2, tensión arterial, p.v.c., tª y diuresis horaria. La complicación detectada con más frecuencia fue la diabetes insípida en un (70%) de los casos, otras complicaciones fueron náuseas, vómitos en un ( 20%) e hipertensión arterial en un (15% ). Conclusiones: Mediante la aplicación del plan de cuidados estandarizados en los pacientes sometidos a cirugía hipofisaria por vía transesfenoidal, se ha mejorado la calidad en los cuidados, se detecta un rápido control de las complicaciones postoperatorias. Se acorta la estancia del enfermo en la U.R.P.A. y se facilita el inicio de un tratamiento precoz de la diabetes insípida

Mutation of vsx genes in zebrafish highlights the robustness of the retinal specification network

Genetic studies in human and mice have established a dual role for Vsx genes in retina development: an early function in progenitors' specification, and a later requirement for bipolar-cells fate determination. Despite their conserved expression patterns, it is currently unclear to which extent Vsx functions are also conserved across vertebrates, as mutant models are available only in mammals. To gain insight into vsx function in teleosts, we have generated vsx1 and vsx2 CRISPR/Cas9 double knockouts (vsxKO) in zebrafish. Our electrophysiological and histological analyses indicate severe visual impairment and bipolar cells depletion in vsxKO larvae, with retinal precursors being rerouted toward photoreceptor or Müller glia fates. Surprisingly, neural retina is properly specified and maintained in mutant embryos, which do not display microphthalmia. We show that although important cis-regulatory remodelling occurs in vsxKO retinas during early specification, this has little impact at a transcriptomic level. Our observations point to genetic redundancy as an important mechanism sustaining the integrity of the retinal specification network, and to Vsx genes regulatory weight varying substantially among vertebrate species

Sabotage in Contests: A Survey

A contest is a situation in which individuals expend irretrievable resources to win valuable prize(s). ‘Sabotage’ is a deliberate and costly act of damaging a rival’s' likelihood of winning the contest. Sabotage can be observed in, e.g., sports, war, promotion tournaments, political or marketing campaigns. In this article, we provide a model and various perspectives on such sabotage activities and review the economics literature analyzing the act of sabotage in contests. We discuss the theories and evidence highlighting the means of sabotage, why sabotage occurs, and the effects of sabotage on individual players and on overall welfare, along with possible mechanisms to reduce sabotage. We note that most sabotage activities are aimed at the ablest player, the possibility of sabotage reduces productive effort exerted by the players, and sabotage may lessen the effectiveness of public policies, such as affirmative action, or information revelation in contests. We discuss various policies that a designer may employ to counteract sabotage activities. We conclude by pointing out some areas of future research