An introduction to nuclear space

This is a small book (48 pages) that contains a revised and extended version of the notes of seminar lectures given by Bessaga. The authors present a nice introduction to nuclear spaces (with all necessary preliminaries) based on Kolmogorov diameters. They consider only some of the most important topics of the theory of nuclear spaces, namely Kolmogorov diameters, nuclear operators, Mityagin's characterization of nuclear spaces, the theorem on absoluteness of bases in nuclear spaces, the uniqueness problem for bases (together with the theorem on quasiequivalence of regular bases), examples of nuclear Fréchet spaces without basis. Of course, many of the important topics in the theory of nuclear spaces are not even touched. Nevertheless, this book may be recommended to anyone who wants to study nuclear spaces, since it is practically independent of other sources and covers an essential part of the theory. Moreover, the authors do their best to help the reader: the proofs of all theorems are complete and the organization of the material is perfect

Age-Dependence of Flow Homeostasis in the Left Ventricle

Background: Intracardiac flow homeostasis requires avoiding blood stasis and platelet activation during its transit through the cardiac chambers. However, the foundations of intraventricular blood washout and its exposure to shear stresses have been poorly addressed. We aimed to characterize and quantify these features in a wide population of healthy subjects and assess the relationships of these indices with age.Methods: We used color-Doppler echocardiography and custom post-processing methods to study 149 healthy volunteers from 26 days to 80 years old. From the intraventricular flow-velocity fields we obtained personalized maps of (1) the residence time of blood in the LV, and (2) the shear index, a metric accounting for the strongest occurrence of shear stresses inside the chamber. From these maps we derived quantitative indices of the overall intraventricular blood washout and shear exposure. We addressed the age-dependence of these indices and analyzed their relationship with age-related changes in filling-flow.Results: The entire intraventricular blood pool was replaced before 8 cycles. Average residence time of blood inside the LV was <3 cycles in all subjects and followed an inverse U-shape relationship with age, increasing from median (IQR) of 1.0 (0.7 to 1.2) cycles in the 1st year of life to 1.8 (1.4–2.2) cycles in young adults (17–30 years old), becoming shorter again thereafter. Shear index showed no relation with age and was bounded around 20 dyn·s/cm2. Regions with the longest residence time and highest shear index were identified near the apex. Differences in the degree of apical penetration of the filling waves and the duration of the late-filling phase explained the age-dependence of residence time (Radj2 = 0.48, p < 0.001).Conclusions: In average, blood spends 1 to 3 beats inside the LV with very low shear stress rates. The apical region is the most prone to blood stasis, particularly in mid-aged adults. The washout of blood in the normal LV is age-dependent due to physiological changes in the degree of apical penetration of the filling waves

Acceso a pruebas complementarias para el diagnóstico de enfermedades infecciosas en las consultas de pediatría de atención primaria

Introducción En los procesos infecciosos la realización de pruebas complementarias puede aumentar la precisión diagnóstica, la adecuación de los tratamientos, así como dar a conocer la epidemiología y patrón de resistencias bacterianas de la comunidad. El Grupo de Patología Infecciosa de la Asociación Española de Pediatría de Atención Primaria (GPI-AEPap) diseñó este estudio para conocer la accesibilidad a pruebas complementarias (PC) y sus resultados que tienen los pediatras que trabajan en atención primaria en el ámbito de la salud pública. Material y métodos Estudio observacional transversal descriptivo de ámbito nacional, a través de una encuesta de cumplimentación voluntaria, distribuida on line a todos los socios de AEPap y a los suscriptores de la lista de distribución PEDIAP entre los meses de abril y mayo de 2017. Resultados Se obtienen 517 respuestas. Se analizan datos del entorno profesional, así como los referidos a la solicitud de pruebas complementarias básicas (hemograma, bioquímica, sistemático de orina), utilización de Test Rápido Detección de Antígeno para Streptococo grupo A (TRDA), sobre cultivos bacterianos, serologías, pruebas diagnósticas de tosferina y tuberculosis (Mantoux) y pruebas de imagen. Conclusiones Hay variabilidad entre CCAA y áreas asistenciales. Se detectan claras áreas de mejora en la accesibilidad a diferentes PC, tiempo de recogida y envío de muestras, demora en la recepción, en los resultados y en tiempos de espera para pruebas de imagen no urgentes. Esto interfiere en la capacidad de intervención y resolución del pediatra de atención primaria. Introduction: The performing of complementary tests in infectious processes can increase the diagnostic precision, the adequacy of treatments, as well as determining the epidemiology and pattern of bacterial resistance of the community. The Infectious Pathology Group of the Spanish Association of Primary Care Paediatrics (GPI-AEPap) has designed this study in order to determine the availability of complementary tests (CT) for paediatricians working in Primary Care of the public health system as well as their results. Material and methods: Observational cross-sectional descriptive national study was carried out using a voluntary self-report questionnaire distributed online to all AEPap members and to the subscribers of the PEDIAP distribution list between the months of April and May 2017. Results: A total of 517 responses were obtained. An analysis was made of the data from the professional environment, as well as those related to the request for basic supplementary tests (blood count, biochemistry, and routine urine analysis), the use of Rapid Antigen Detection Test for group A Streptococcus, bacterial cultures, serology, diagnostic tests for pertussis and tuberculosis (Mantoux), as well as imaging tests. Conclusions: There is variability between Autonomous Communities and healthcare areas. Areas for improvement were found in the accessibility to different CT, collection time and sending of samples, delay in receiving results, as well as waiting times for non-urgent imaging tests. These affect the intervention and resolution capacity of the primary care paediatrician

Mechanical Bonds and Topological Effects in Radical Dimer Stabilization

While mechanical bonding stabilizes tetrathiafulvalene (TTF) radical dimers, the question arises: what role does topology play in catenanes containing TTF units? Here, we report how topology, together with mechanical bonding, in isomeric [3]- and doubly interlocked [2]catenanes controls the formation of TTF radical dimers within their structural frameworks, including a ring-in-ring complex (formed between an organoplatinum square and a {2+2} macrocyclic polyether containing two 1,5-dioxynaphthalene (DNP) and two TTF units) that is topologically isomeric with the doubly interlocked [2]catenane. The separate TTF units in the two {1+1} macrocycles (each containing also one DNP unit) of the isomeric [3]catenane exhibit slightly different redox properties compared with those in the {2+2} macrocycle present in the [2]catenane, while comparison with its topological isomer reveals substantially different redox behavior. Although the stabilities of the mixed-valence (TTF2)^(•+) dimers are similar in the two catenanes, the radical cationic (TTF^(•+))_2 dimer in the [2]catenane occurs only fleetingly compared with its prominent existence in the [3]catenane, while both dimers are absent altogether in the ring-in-ring complex. The electrochemical behavior of these three radically configurable isomers demonstrates that a fundamental relationship exists between topology and redox properties

Sequence-selective assembly of tweezer-molecules on linear templates enables frameshift-reading of sequence information

Monomer-sequence information in synthetic copolyimides can be recognised by tweezer-type molecules binding to adjacent triplet-sequences on the polymer chains. In the present paper different tweezer-molecules are found to have different sequence-selectivities, as demonstrated in solution by 1H NMR spectroscopy and in the solid state by single crystal X-ray analyses of tweezer-complexes with linear and macrocyclic oligo-imides. This work provides clear-cut confirmation of polyimide chain-folding and adjacent-tweezer-binding. It also reveals a new and entirely unexpected mechanism for sequence-recognition which, by analogy with a related process in biomolecular information processing, may be termed "frameshift-reading". The ability of one particular tweezer-molecule to detect, with exceptionally high sensitivity, long-range sequence-information in chain-folding aromatic copolyimides, is readily explained by this novel process

Self-assembled peptide-inorganic nanoparticle superstructures: From component design to applications

Peptides have become excellent platforms for the design of peptide-nanoparticle hybrid superstructures, owing to their self-assembly and binding/recognition capabilities. Morover, peptide sequences can be encoded and modified to finely tune the structure of the hybrid systems and pursue functionalities that hold promise in an array of high-end applications. This feature article summarizes the different methodologies that have been developed to obtain self-assembled peptide-inorganic nanoparticle hybrid architectures, and discusses how the proper encoding of the peptide sequences can be used for tailoring the architecture and/or functionality of the final systems. We also describe the applications of these hybrid superstructures in different fields, with a brief look at future possibilities towards the development of new functional hybrid materials. This journal i