Impact of Surface Treatment on the Corrosion Resistance of ASTM F138-F139 Stainless Steel for Biomedical Applications

AbstractAISI 316 LVM stainless steel type considered in ASTM F138 and F139 standards for implant devices is widely used, in particular for orthopedic surgery, because it combines good biofunctionality and acceptable biocompatibility at low costs. Adequate interaction of these materials with the human body and its capability to reach the desired service level are determined by the surface preparation. The goal of the present work is to relate the surface roughness parameters with the localized corrosion resistance of AISI 316 LVM stainless steel grit blasted for different times and passivated with nitric acid. At intermediate blasting times the roughness parameters attain an extreme value and this surface condition corresponds with the maximum pitting corrosion resistance

Integrin activation - the importance of a positive feedback

Integrins mediate cell adhesion and are essential receptors for the development and functioning of multicellular organisms. Integrin activation is known to require both ligand and talin binding and to correlate with cluster formation but the activation mechanism and precise roles of these processes are not yet resolved. Here mathematical modeling, with known experimental parameters, is used to show that the binding of a stabilizing factor, such as talin, is alone insufficient to enable ligand-dependent integrin activation for all observed conditions; an additional positive feedback is required.Comment: in press in Bulletin of Mathematical Biolog

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Estudios de marcado y recaptura de especies marinas

Los resultados obtenidos del marcado y posterior recaptura de los ejemplares son una herramienta muy valiosa para contribuir a mejorar el conocimiento de la biología y ecología de una especie, examinando ciertos aspectos como son: el crecimiento, los movimientos o migraciones, la mortalidad o supervivencia, la abundancia y distribución de la especie, el hábitat y diferenciación de poblaciones o stocks. Actualmente la técnica de marcado se aplica a muchas especies, tanto terrestres como marinas, pertenecientes a diversos grupos zoológicos: peces, crustáceos, reptiles, moluscos y mamíferos. Este libro repasa algunos ejemplos de marcado de especies marinas de interés comercial. No todas las especies pueden ser marcadas, porque es necesario cumplir una serie de requisitos para poder llevar a cabo con éxito un experimento de marcado. En uno de los apartados de esta guía, se describen los distintos aspectos a tener en cuenta para obtener buenos resultados. Se describen los principales proyectos de marcado actualmente en ejecución o en marcha llevados a cabo por el Instituto Español de Oceanografía (IEO). En primer lugar, se describe brevemente la especie, su distribución, crecimiento, reproducción, alimentación, etc. A continuación, se presenta la información del marcado, es decir, campañas realizadas, número de ejemplares marcados y algunos de los resultados obtenidos hasta la fecha a partir de las recapturas disponibles. En algunas especies, los programas de marcado se llevan realizando desde hace más de 20 años, como es el caso del atún rojo, por lo que la información disponible es bastante amplia. En otros casos por el contrario como la merluza, los proyectos son relativamente recientes, no obstante los resultados son bastante interesantes y prometedores.Nowadays many different marine animals are being tagged. This book summarizes recent tagging programs carried out by the Spanish Institute of Oceanography (IEO). Although the objectives of these various studies mainly depend on the species and each project in particular, the general aim is to better understand the biology and ecology of these animals the structure and dynamics of their populations and their capacity to respond to human activities. This book provides an overview of different aspects of this technique such as a brief history of tagging, the types of tags currently used, including both conventional and electronic tags, where and how to put them on the marine animals, some recommendations regarding how to perform a tagging survey and where to go or what to do if anyone recovers a tagged fish or marine animal. The book then summarizes the main species tagged by the IEO, making a short description of their biology followed by some of the results obtained from tagging studies undertaken until now. Other applications are to know the spatial distribution (spawning or feeding areas), estimate growth parameters, mortality and survival rates, longevity, the size of the population or identifying stocks. Nowadays the advances in electronics have also open new fields such us the possibility of tracking an animal and knowing its habitat preferences and behaviour. Besides some of these tags have the capacity of recording this information during long periods and sending the data from long distances even without the need to recover the animal. Tagging activities constitute a very useful tool to improve the knowledge of many species and contribute to their management and conservation. For that reason this methodology is included in many IEO projects in which other activities like the monitoring of the fishery (landings, fishing effort, fleet characteristics, fishing areas, biological sampling, etc.) are carried out. Some projects are related with coastal pelagic fisheries including anchovy, sardine and mackerel or oceanic pelagic fisheries like tuna and billfish species and pelagic sharks. Others are focused on benthic and demersal species such as hake, black spot seabream, anglerfish, flatfish, etc. Nevertheless not all species can be tagged, as they have to survive being caught and handled before being release. For this reason, tagging techniques may not easily be applied to some species.Versión del edito

More than smell - COVID-19 is associated with severe impairment of smell, taste, and chemesthesis

Recent anecdotal and scientific reports have provided evidence of a link between COVID-19 and chemosensory impairments, such as anosmia. However, these reports have downplayed or failed to distinguish potential effects on taste, ignored chemesthesis, and generally lacked quantitative measurements. Here, we report the development, implementation, and initial results of a multilingual, international questionnaire to assess self-reported quantity and quality of perception in 3 distinct chemosensory modalities (smell, taste, and chemesthesis) before and during COVID-19. In the first 11 days after questionnaire launch, 4039 participants (2913 women, 1118 men, and 8 others, aged 19-79) reported a COVID-19 diagnosis either via laboratory tests or clinical assessment. Importantly, smell, taste, and chemesthetic function were each significantly reduced compared to their status before the disease. Difference scores (maximum possible change ±100) revealed a mean reduction of smell (-79.7 ± 28.7, mean ± standard deviation), taste (-69.0 ± 32.6), and chemesthetic (-37.3 ± 36.2) function during COVID-19. Qualitative changes in olfactory ability (parosmia and phantosmia) were relatively rare and correlated with smell loss. Importantly, perceived nasal obstruction did not account for smell loss. Furthermore, chemosensory impairments were similar between participants in the laboratory test and clinical assessment groups. These results show that COVID-19-associated chemosensory impairment is not limited to smell but also affects taste and chemesthesis. The multimodal impact of COVID-19 and the lack of perceived nasal obstruction suggest that severe acute respiratory syndrome coronavirus strain 2 (SARS-CoV-2) infection may disrupt sensory-neural mechanisms. © 2020 The Author(s) 2020. Published by Oxford University Press. All rights reserved

GC-EoS extension to alkylphosphate imidazolium ionic liquids

In this work, the Group Contribution Equation of State (GC-EoS) is extended to model two new ionic liquid families, namely, 1-alkyl-3-methylimidazolium dimethylphosphate ([-MeIm]+[Me2PO4]-) and 1-alkyl-3-methylimidazolium diethylphosphate ([-MeIm]+[Et2PO4]-). Pure group parameters for the functional groups [-MeIm]+[Me2PO4]- and [-MeIm]+[Et2PO4]- and interaction parameters between these groups and the main paraffinic and aromatic subgroups (CH3, CH2, ACH, AC, ACCH3, CH2=CH) were estimated using infinite dilution activity coefficients from literature. In order to evaluate the performance of the new parameters, the model was compared with experimental data on the phase behavior of binary mixtures, showing an average relative deviation of 4.5%.Fil: de Pablo Nisa, L.. Universidad de Valladolid; EspañaFil: Sánchez, Francisco Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Bermejo, M.D.. Universidad de Valladolid; EspañaFil: Pereda, Selva. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. University of KwaZulu-Natal; Sudáfric