Desprendimiento de retina tras la cirugía de cristalino transparente con lentes intraoculares EDOF y multifocales: una revisión narrativa / Retinal detachment after refractive lens exchange with EDOF and multifocal intraocular lenses: A narrative review

La cirugía de cristalino transparente (RLE) permite corregir las ametropías y la presbicia mediante el reemplazo del cristalino por una lente intraocular (LIO), ya sea monofocal, multifocal (MIOL) o de profundidad de foco extendida (EDOF). El desprendimiento de retina (DR) es uno de los eventos adversos más graves tras la RLE. El objetivo de este estudio fue revisar la evidencia y los resultados clínicos relacionados con el riesgo de DR después de la RLE. Se realizó una búsqueda utilizando PubMed y un procedimiento de bola de nieve para identificar estudios originales y series de casos. Según la bibliografía, los pacientes < 60 años con longitudes axiales > 23 mm tienen el mayor riesgo de DR. Solo nueve artículos reportaron la agudeza visual (AV) tras el DR en RLE, y solo 25% de los ojos mostraron una AV > 20/40. Teniendo en cuenta que la disminución de la AV tras el DR se puede dar con todos los tipos de LIO independientemente de su diseño óptico, la actitud más acertada al realizar una RLE sería una cuidadosa selección del paciente, evitando aquellos ojos con factores de riesgo para DR (AU)

Refractive lens exchange (RLE) allows to correct ametropias and presbyopia by replacing the crystalline lens with a monofocal, extended depth of focus or multifocal intraocular lens (IOL). Retinal detachment (RD) is one of the most serious adverse events after RLE. This study aimed to review the evidence related to the risk of RD after RLE and its clinical outcomes. A search using PubMed and a snowball search approach was conducted to identify articles and case reports. According to the literature, patients <60 years old with axial lengths >23 mm have the higher postoperative risk of RD. Only nine articles reported visual acuity (VA) after RD in RLE, and only 25% of eyes had a VA>20/40. Considering that the decrease in VA might be uniform for all types of IOLs after RD, surgeons should focus on preventing the RD by means of selecting the appropriate patient, rather than choosing on a particular IOL optical design (AU)

Retinal detachment after refractive lens exchange: A narrative review.

Refractive lens exchange (RLE) allows to correct ametropias and presbyopia by replacing the crystalline lens with an extended depth of focus or multifocal intraocular lens (IOL). Retinal detachment (RD) is one of the most serious adverse events after RLE. This study aimed to review the evidence related to the risk of RD after RLE and clinical outcomes. A search using PubMed and a snowball search approach was conducted to identify articles and case reports. According to the literature, the risks of RD should be considered in patients <60 years old with axial lengths >23 mm. Only nine articles reported visual acuity (VA) after RD in RLE, and only 25% of eyes had a VA > 20/40. Considering that the decrease in VA might be uniform for all types of IOLs after RD, surgeons should focus on selecting the patient to prevent RD rather than on a particular IOL optical design based on the potential risk of DR.

A symmetric version of the Euler equations by using Generalized Bernoulli Method.

The aim of this article is to show a way to extend the usefulness of the Generalized Bernoulli Method (GBM) with the purpose to apply it for the case of variational problems with functionals that depend explicitly of all the variables. Moreover, after expressing the Euler equations in terms of this extension of GBM, we will see that the resulting equations acquire a symmetric form, which is not shared by the known Euler equations. We will see that this symmetry is useful because it allows us to recall these equations with ease. The presentation of three examples shows that by applying GBM, the Euler equations are obtained just as well as it does the known Euler formalism but with much less effort, which makes GBM ideal for practical applications. In fact, given a variational problem, GBM establishes the corresponding Euler equations by means of a systematic procedure, which is easy to recall, based in both elementary calculus and algebra without having to memorize the known formulas. Finally, in order to extend the practical applications of the proposed method, this work will employ GBM with the purpose to apply it for the case of solving isoperimetric problems.

Maintenance of sterility in SMS packaging in dental environments: concern with biosafety

Healthcare services must be guided by biosafety practices and microbial control. This control is highly influenced by humidity, which directly impacts the maintenance of sterility of the materials used in the appointments. High concentration of moisture, in the form of aerosol, splashes and spills, is caused during dental care. During the COVID-19 times the contamination by aerosol and droplets worries greatly. Considering that it could cause harm to the sterility of an autoclaved material, especially in dental environments, the objective was to evaluate the behavior of SMS sterilization packages (Spunbonded / Meltblown / Spunbonded) against microbial penetration in an aqueous vehicle. SMS of three brands were challenged, equally divided into two groups: virgin and processed (subjected to a single autoclaving cycle). Each specimen was aseptically deposited on Macconkey agar. Subsequently, 5 µL of Escherichia coliATCC 25922 saline solution [108CFU mL-1] was deposited in center of the SMS specimen and the dish incubated at36°C/ 48h. Reading was performed by the presence or absence of bacterial growth typical of the species under the SMS, observed on the back of Petri dish. The lowest penetration rate observed was 60% for one of the brands in the virgin condition, and 75% for two brands in the processed condition. Statistical analysis showed an association between bacterial penetration and the evaluated group, this association being valid only in the virgin condition. The different SMS behave similarly in terms of resistance to bacterial penetration after being processed. The data show that moisture can assist in bacterial transport through sterilized SMS. Therefore, SMS packages are not able to prevent bacterial penetration, and possibly other microorganisms, when in aqueous vehicles, offering a potential risk of breaking the aseptic chain. Thus, care must be taken in routines for handling and storage sterile packaging.

Adapting evaluation method of skills acquisition in basic cardiopulmonary resuscitation among year 5 and year 6 primary school pupils during the COVID-19 lockdown: a pilot study.

OBJECTIVE: This longitudinal descriptive study aimed to evaluate cognitive skills acquisition in basic Cardiopulmonary Resuscitation (bCPR) among a group of Year 5 and Year 6 primary school pupils. The study made use of online tools due to the impossibility of conventional methods during the COVID-19 lockdown. MATERIALS AND METHODS: Pupils received formal training in bCPR. Training was imparted uniformly by a teacher at the school (qualified in Basic Life Support -BLS- and Advanced Life Support -ALS- training by the CPR National Plan). The skills acquired (those proposed as essential for bCPR training by the European Resuscitation Council) were evaluated fifteen weeks later. Skills acquisition was evaluated by means of an online questionnaire developed specifically for the study. RESULTS: In all the cognitive skills included in bCPR training, the acquisition level achieved was over 65%. Acquisition of knowledge of the anatomical areas at which cardiac massage must be applied and the means of emergency systems activation was high, while 25.5% of pupils knew the order in which maneuvers should be performed. Pupils' self-confidence and self-perception of their capacity to act when faced with a real CPR situation increased significantly. CONCLUSIONS: Primary school pupils learned all the cognitive skills involved in bCPR, showing high levels of skills acquisition and positive self-perception of their capacity to apply them.

Detección de Leptospira spp. (Spirochaetales: Leptospiraceae) en muestras ambientales de regiones habitadas por poblaciones vulnerables del norte argentino / Leptospira spp. (Spirochaetales: Leptospiraceae) detection in environmental samples from geographical regions inhabited by vulnerable communities in northern Argentina

Resumen La leptospirosis continúa siendo hoy en día un problema para la salud pública, principalmente en poblaciones de bajos recursos socioeconómicos. En este trabajo se presenta la detección de leptospiras patógenas en muestras ambientales (aguas y barros) provenientes de regiones del norte argentino (provincias de Formosa, Salta, Santiago del Estero, Misiones y Chaco) con variadas características climatológicas habitadas por poblaciones vulnerables. De las 89 muestras analizadas, en el 24,7% fue posible detectar molecularmente la presencia de leptospiras patógenas. La prevalencia por tipo de muestra fue de 27,8% para las aguas y 11,8% para los barros. Todas las localidades muestreadas presentaron al menos una muestra positiva a alguna de las pruebas realizadas, por lo que el presente trabajo refleja la necesidad de profundizar los estudios de la leptospirosis en distintas regiones de la Argentina.

Abstract Leptospirosis remains as a major public health problem nowadays, mainly affecting vulnerable communities with low socioeconomic resources. In this study, the molecular detection of pathogenic leptospires from environmental samples (water and mud) from northern Argentina (Formosa, Salta, Santiago del Estero, Misiones and Chaco provinces) is described. Samples were obtained from regions with varied climatological features, all inhabited by vulnerable communities. From the 89 samples that were analyzed, 24.7% showed molecular evidence of the presence of pathogenic leptospires. Prevalence by sample type was: 27.8% in water samples and 11.8% in mud samples. All the sampled regions showed at least one positive sample. This result highlights the need of further research regarding leptospirosis in different regions of Argentina.

Pollination of the strongly scented Sarcoglottis acaulis (Orchidaceae) by male orchid bees: nectar as resource instead of perfume.

The Neotropical orchid genus Sarcoglottis comprises ~40 species, which emit strong floral scents, presumably involved in pollinator attraction. Information on basic aspects of its natural history is scant, with the few studies available so far pointing to nectar-seeking orchid bees as pollinators. Here, we investigated the reproductive biology of Sarcoglottis acaulis, addressing the ecological meaning of its floral scent. In Atlantic Forest fragments of NE Brazil, we described the floral biology, determined the breeding system and recorded the pollinators of S. acaulis. Additionally, we chemically characterized its floral scent and assessed its role on pollinator attraction. Although self-compatible, S. acaulis depends on pollinators to boost fruit set. Male orchid bees of Eulaema atleticana and E. niveofasciata were the only recorded pollinators. They foraged for nectar only, in spite of the strong scent emitted by S. acaulis flowers. The floral scent is composed of six compounds, of which geraniol and nerol elicited electroantennographic responses in Eulaema bees. A synthetic mixture of these compounds attracted Eulaema bees in field assays but did not trigger the stereotyped scent-gathering behaviour. The floral scent of S. acaulis acts in signalling and nectar is the sole reward for pollinators. Despite the low pollinator frequency, S. acaulis shows a high fruit set (77%), particularly when compared to other orchids. Attributes such as pollinia that release small pollen loads, allowing a single pollinia-carrying bee to pollinate several flowers, low amount of nectar, steady-state flowering and traplining behaviour of pollinators, might act together to assure this outstanding fruit set.

Genotoxic and mutagenic effects of methyl ether dillapiole on the development of Aedes aegypti (Diptera: Culicidae).

Dillapiole, extracted from Piper aduncum essential oil and its derivatives, has been shown to be a potential alternative to the control of Aedes aegypti, which has become resistant to synthetic insecticides. Methyl ether dillapiole (MED) and temephos (TM) were compared to complement the data on the genotoxicity and developmental changes of Ae. aegypti. Over four generations (G1 -G4 ), third stage larvae were treated with MED at 60, 80 and 100 µg/mL and TM at 0.002, 0.005 and 0.007 µg/mL for 4 h. Adult females were separated to estimate oviposition and hatching rates, and total egg length. Over the four generations, a significant reduction was recorded in oviposition and hatching rates, and in mean egg length (Tukey, P < 0.05), compared with the negative control (NC). Cytological slide preparations were done from adult oocytes and larval neuroblasts. The cumulative effects of genotoxic (bridges, budding and nuclear fragmentation) and mutagenic (micronucleus and chromosomal breakage) damage was observed in the neuroblasts and oocytes of exposed mosquitoes. Developmental changes and damage to the genome of MED-treated Ae. aegypti were greater than those caused by TM. Further studies should focus on understanding the effects of the MED molecule on Ae. aegypti.

Effects of Soil Conditions on Root Rot of Soybean Caused by Fusarium graminearum.

Fusarium graminearum is an important soybean pathogen that causes seedling disease, root rot, and pre- and postemergence damping-off. However, effects of soil conditions on the disease are not well understood. The objective of this greenhouse study was to determine the impacts of soil texture, pH, and soil moisture on seedling root rot symptoms and detrimental effects on seedling development caused by F. graminearum. F. graminearum-infested millet was added (10%, vol/vol) to soil with four different textures (sand, loamy sand, sandy loam, and loam). Soil moisture was maintained at saturation, field capacity or permanent wilting point at soil pH levels of 6 or 8. Seedlings were evaluated 4 weeks after planting for root rot, root length, root and shoot dry weights, leaf area, and F. graminearum colonization (by qPCR). There was a significant interaction between soil moisture and soil texture for root rot assessed visually (P < 0.0001). Highest severity (67%) and amount of F. graminearum DNA were observed at pH 6 and permanent wilting point in sandy loam soils. Pot saturation resulted in the lowest levels of disease in sandy loam and loam soils (11.6 and 10.8%, respectively). Reductions in seedling growth parameters, including root length, foliar area, shoot and root dry weights, and root tips, relative to the noninfested control, were significantly greater in sandy loam soils. In contrast, there were no significant growth reductions in sand. This study showed that levels of root rot increased under moisture-limiting conditions, producing detrimental effects on plant development.

[Seroprevalence of antibodies against measles virus in Galicia: trends during the last ten years depending on age and sex]. / Seroprevalencia de anticuerpos frente al virus del sarampión en Galicia: tendencias durante los últimos diez años en función de la edad y sexo.

OBJECTIVE: In 1998, the Europe Region of the World Health Organization set the goal of eliminating measles. In this study, the prevalence of immunity against measles virus in the population of the health area of Santiago de Compostela was analyzed based on data obtained between 2008-2018. METHODS: A total of 7,150 different patients were studied and divided into groups according to their year of birth: 2010-2017, 2000-2009, 1990-1999, 1980-1989, 1953-1979 and <1953. The serum determination of IgG against measles virus was performed using a commercialized chemiluminescent immunoassay. RESULTS: A minimum (76%) was observed for measles virus protection rates in those born between 1990-1999. By age group it was seen that in all groups the women presented a higher percentage of antibodies against measles. In a logistic regression model with year of birth and sex, an odds ratio of 1.06 (p<0.001) was obtained for the year of birth and of 0.82 (p=0.0013) for sex. CONCLUSIONS: It was observed lower seroprevalences from the implantation of the vaccine and a more pronounced change during the implantation period. From the vaccination plan for measles of the year 2000 in Galicia, the rates of protection against the virus of the measles have been increasing in our area. Although there is a greater proportion of women protected against men, these differences are small.

Regenerative and Resorbable PLA/HA Hybrid Construct for Tendon/Ligament Tissue Engineering.

Tendon and ligament shows extremely limited endogenous regenerative capacity. Current treatments are based on the replacement and or augmentation of the injured tissue but the repaired tissue rarely achieve functionality equal to that of the preinjured tissue. To address this challenge, tissue engineering has emerged as a promising strategy. This study develops a regenerative and resorbable hybrid construct for tendon and ligament engineering. The construct is made up by a hollow poly-lactic acid braid with embedded microspheres carrying cells and an anti-adherent coating, with all the parts being made of biodegradable materials. This assembly intends to regenerate the tissue starting from the interior of the construct towards outside while it degrades. Fibroblasts cultured on poly lactic acid and hyaluronic acid microspheres for 6 h were injected into the hollow braid and the construct was cultured for 14 days. The cells thus transported into the lumen of the construct were able to migrate and adhere to the braid fibers naturally, leading to a homogeneous proliferation inside the braid. Moreover, no cells were found on the outer surface of the coating. Altogether, this study demonstrated that PLA/HA hybrid construct could be a promising material for tendon and ligament repair.

Tratamento da mordida aberta anterior: revisão de literatura / Treatment of previous open bite: literary review

Objetivo: realizar uma revisão de literatura sobre os tipos de tratamento empregados na correção da mordida aberta anterior. Materiais e métodos: foi realizada uma busca nas bases de dados PubMed, SciELO e Google Acadêmico. Os termos inseridos na pesquisa foram: Mordida Aberta; Ortodontia Corretiva; Ortodontia; Ortodontia Interceptora; Open Bite; Orthodontics, Corrective; Orthodontics; Orthodontics, Interceptive. Revisão da Literatura: a mordida aberta anterior (MAA) é uma má oclusão dentária que pode promover alteração do perfil e da fisionomia do indivíduo, dificultando também a apreensão e o corte dos alimentos. A MAA é uma das más oclusões de maior comprometimento estético-funcional, podendo ser dentária ou esquelética. A etiologia da mordida aberta anterior é multifatorial, sendo que as principais causas são hereditariedade e causas ambientais. Esses fatores interferem no crescimento e desenvolvimento normais das estruturas faciais, modificando não somente a morfologia, mas, também, a função do sistema estomatognático. Considerações finais: conclui-se que o diagnóstico precoce e a remoção do fator etiológico são fundamentais para a evolução adequada do tratamento ortodôntico.(AU)

Objective: to perform a literature review on the types of treatment used in anterior open bite correction. Materials and methods: a search was performed in the PubMed, SciELO, and Google Scholar databases. The terms entered in the search were Mordida Aberta; Ortodontia Corretiva; Ortodontia; Ortodontia Interceptora; Open Bite; Orthodontics, Corrective; Orthodontics; Orthodontics, Interceptive. Literature Review: anterior open bite (AOB) is a dental malocclusion that may change the profile and physiognomy of individuals, making it difficult to grasp and cut food. The AOB is one of the malocclusions with the most aesthetic and functional impairments, and it may be dental or skeletal. The etiology of anterior open bite is multifactorial and the main causes are heredity and environmental causes. These factors interfere with the normal growth and development of facial structures, modifying not only the morphology but also the function of the stomatognathic system. Final considerations: it is concluded that the early diagnosis and removal of the etiological factor are essential for the proper evolution of the orthodontic treatment.(AU)

Slow-wave sleep and androgens: selective slow-wave sleep suppression affects testosterone and 17α-hydroxyprogesterone secretion.

OBJECTIVES: Levels of steroid hormones such as androgens and cortisol exhibit circadian variation, and their fluctuations are related to the sleep-wake cycle. Currently, the functional role of different stages of sleep in steroid hormone secretion remains unclear. The present study aims to explore the effect of slow-wave sleep (SWS) suppression on morning levels of cortisol and androgens. METHODS: Twelve healthy male volunteers participated in two experimental sessions: a session with selective SWS suppression during night sleep and a session with regular night sleep (control). SWS suppression was achieved by stimulation using an acoustic tone. Salivary samples were collected in the morning immediately after awakening and again 40 min later. The samples were analysed by liquid chromatography-tandem mass spectrometry for testosterone, androstenedione (Ad), dehydroepiandrosterone (DHEA), 17α-hydroxyprogesterone (17-OHP), and cortisol. RESULTS: SWS suppression reduced overall SWS duration by 54.2% without significant changes in total sleep time and sleep efficiency. In the session with selective SWS suppression, the average level of morning testosterone was lower than in the control session (p = 0.017). Likewise, 17-OHP was lower in the SWS suppression condition (p = 0.011) whereas the ratio of DHEA/Ad was higher (p = 0.025). There were no significant differences between sessions in cortisol, Ad, or DHEA concentrations. CONCLUSIONS: The effect of selective SWS suppression on morning levels of testosterone and 17-OHP points to the importance of SWS for the synthesis and secretion of androgens. These results suggest that chronic sleep problems, which lead to reduced SWS, increase the risk for the development of androgen deficiency in the long term.

Cerebral tuberculosis in a patient with systemic lupus erythematosus following cyclophosphamide treatment: a case report.

Central nervous system (CNS) tuberculosis (TB) is a rare but catastrophic event in patients with systemic lupus erythematosus (SLE). Here we report a case of cerebral TB in a patient with lupus myocarditis and nephritis, following cyclophosphamide immunosuppression. To our knowledge this is the first reported case of cerebral TB in SLE in a non-endemic country. A 31-year-old female with SLE and a history of regular travel to Kenya presented to our centre with clinical features of acute heart failure. She was diagnosed with severe lupus myocarditis, and a renal biopsy also confirmed lupus nephritis. Prior to admission, she had also had a cough, fever and weight loss and was under investigation for suspected TB infection. She was treated with ivabradine, beta-blockers and diuretics together with methylprednisolone and cyclophosphamide immunosuppression. Subsequent sputum cultures confirmed TB and she was commenced on triple therapy. Despite this, she developed confusion, dizziness, blurred vision and fluctuating consciousness. Magnetic resonance imaging (MRI) and lumbar puncture revealed CNS TB infection resulting in meningitis. This was later complicated by obstructive hydrocephalus due to TB abscesses. A ventriculoperitoneal (VP) shunt was inserted and TB medications were given intravenously (IV) with dexamethasone. Following a prolonged hospital admission, the patient eventually recovered and rituximab treatment was used to control her SLE. TB infection has been associated with SLE flares. It is likely in this case that TB exacerbated a lupus flare and subsequent immunosuppression resulted in mycobacterial dissemination to the CNS. Systemic and CNS features of TB and SLE are difficult to distinguish and their contemporaneous management represents a diagnostic and therapeutic challenge.

The use of reduced glutathione (GSH) as antioxidant for cryopreserved sperm in dogs / O uso da glutationa reduzida (GSH) como antioxidante na criopreservação seminal em cães

The aim of this study was to evaluate the effect of supplementation with different concentrations of reduced glutathione GSH (0; 5; 7.5; 10mM) in the extender for cryopreservation in dogs with evaluations performed after glycerolization (chilled) and thawing (thawed). For this purpose, we used 8 dogs and two semen collections were performed in a weekly interval, totaling 16 semen samples. The sperm were analyzed by automatic sperm motility (CASA) and flow cytometry analysis of mitochondrial potential (JC1 dye) and membrane/acrosome integrity (FITC-PI dyes). We evaluated subjectively the membrane and acrosome integrity, mitochondrial activity and DNA integrity. Seminal plasma was evaluated for lipid peroxidation (TBARS concentration). Chilled and thawed samples supplemented with 7.5 and 10mM of GSH had lower percentage of sperm with high (DAB - Class I) and medium (DAB - Class II) mitochondrial activity. And 10mM of GSH had higher percentage of low mitochondrial activity (DAB - Class III). Moreover, thawed samples of 10mM of GSH had high DNA fragmentation rates. Probably by a reductive stress effect on mitochondria which lead to an increase in reactive oxygen species, and a mitochondrial malfunction.(AU)

O objetivo deste estudo foi avaliar o efeito da suplementação com diferentes concentrações de glutationa reduzida (GSH - 0; 5; 7,5; 10mM) para criopreservação em cães com avaliações realizadas após glicerolização (refrigeração) e descongelação. Para tal, foram utilizados oito cães e foram realizadas duas coletas de sêmen em intervalo semanal, totalizando 16 amostras de sêmen. Foram avaliadas a motilidade espermática computadorizada (CASA) e a análise de citometria de fluxo do potencial mitocondrial (sonda JC-1) e integridade da membrana/acrossomal (sonda FITC-PI). Subjetivamente foi avaliada a integridade da membrana plasmática e do acrossomal, atividade mitocondrial e integridade do DNA. O plasma seminal foi avaliado quanto à peroxidação lipídica (concentração de TBARS). As amostras refrigeradas e descongeladas suplementadas com 7,5 e 10mM de GSH apresentaram menor porcentagem de espermatozoides com alta atividade mitocondrial (DAB - Classe I) e média (DAB - Classe II). Na concentração de 10mM de GSH, apresentaram maior porcentagem de baixa atividade mitocondrial (DAB - Classe III). Além disso, amostras descongeladas de 10mM de GSH apresentaram taxas de fragmentação de DNA elevadas, provavelmente por efeito de estresse redutivo sobre as mitocôndrias que elevam as espécies reativas de oxigênio e disfunção mitocondrial.(AU)

[Infection by the Epstein-Barr virus between the years 2006-2015 in the health area of Santiago de Compostela. Relationship with age and sex]. / Primoinfección por el virus Epstein-Barr entre los años 2006 a 2015 en el área sanitaria de Santiago de Compostela. Relación con edad y sexo.

OBJECTIVE: In Spain, the age and sex to which the primary infection by EBV is produced is poorly studied. The objective of this work is to know its relation with the presence of the primary infection by EBV between the years 2006 and 2015 in our health area. METHODS: From the Santiago de Compostela health area between 2006 and 2015, 578 patients with serological patterns of EBV primoinfection were selected. This patients presented serological results of IgM-VCA positive, IgG-VCA positive and EBNA negative. RESULTS: We found 260/578 (45%) adolescents (11- 19 years). In the number of cases by age the maximum was observed, at 2 and 16 years. Between 14-19 years, 62% (79/127) of women between 14-16 years of age, median age 15.8 years (IQ: 14.8-16.4) compared to 48% (49/102) of men, median age 16 years (IQ: 15.7-16.6) (p = 0.032, p = 0.02, respectively). CONCLUSIONS: As in our study, in the developed countries the majority of primary infections by EBV occur in adolescence and a bimodal distribution is observed in relation to age. During adolescence women acquire before men the first infection by EBV.

Phenomenological friction equation for turbulent flow of Bingham fluids.

Most discussions in the literature on the friction coefficient of turbulent flows of fluids with complex rheology are empirical. As a rule, theoretical frameworks are not available even for some relatively simple constitutive models. In the present work, a formula is proposed for the evaluation of the friction coefficient of turbulent flows of Bingham fluids. The developments combine a fresh analysis for the description of the microscales of Kolmogorov and the phenomenological turbulence model of Gioia and Chakraborty [G. Gioia and P. Chakraborty, Phys. Rev. Lett. 96, 044502 (2006)PRLTAO0031-900710.1103/PhysRevLett.96.044502]. The resulting Blasius-type friction equation is tested against some experimental data and shows good agreement over a significant range of Hedstrom and Reynolds numbers. Comments on pressure measurements in yielding fluids are made. The limits of the proposed model are also discussed.

Consideraciones éticas en el diagnóstico presintomático de ataxias espinocerebelosas autosómico dominantes / Ethical considerations in presymptomatic diagnosis of autosomal dominant spinocerebellar ataxias

Introducción: Existe información limitada de la realización de diagnóstico presintomático en ataxias espinocerebelosas (SCA) autosómicas dominantes. La llegada del diagnóstico molecular, además de brindar la posibilidad de realizar identificación en pacientes portadores de distintas enfermedades, permitió también la posibilidad de detectar enfermedades incluso antes de su presentación. Esto atrajo la atención sobre las implicaciones éticas que deberían ser consideradas en estos sujetos, con la finalidad de salvaguardar su bienestar físico y psicológico. Desarrollo: La SCA está compuesta por un grupo de trastornos neurodegenerativos con patrón de herencia autosómico dominante. Existen pocas publicaciones que describen el proceso de asesoramiento y los lineamientos considerados durante el proceso de diagnóstico presintomático. El número de integrantes de los equipos multidisciplinarios, sus áreas de especialidad y número de sesiones durante el asesoramiento es variable en cada uno de los trabajos analizados. Sin embargo, las bases para su realización tienen origen en documentos comunes, en los cuales algunos de los autores han participado en fechas más recientes. Conclusiones: El diagnóstico presintomático debe ser realizado bajo lineamientos que salvaguarden el bienestar de los sujetos. Sería recomendable que el diagnóstico de SCA sea realizado solo a pacientes con clínica sugestiva, mayores de 18 años y con un riesgo mínimo del 50%. Deben estar disponibles esquemas de asesoramiento genético en todos aquellos centros que pretenden realizar diagnóstico de SCA antes de la presentación de síntomas (AU)

Introduction: Information on achieving presymptomatic diagnosis of spinocerebellar ataxia (SCA) is limited. The advent of molecular diagnosis makes it possible to identify the carriers of different diseases and has also introduced the prospect of detecting diseases even before their onset. This has drawn attention to the ethical implications that must be considered in these subjects with a view to preserving their physical and psychological well-being. Development: SCA is composed of a group of neurodegenerative disorders with autosomal dominant inheritance. Only a few publications have described the genetic counselling processes and guidelines to be followed during the process of presymptomatic diagnosis (PSD). The size of the multidisciplinary teams, their areas of expertise, and the number of counselling sessions are different for each of the studies analysed here. However, the basis of presymptomatic diagnosis originates in common guidelines to which members of our team have contributed recently. Conclusion: Presymptomatic diagnosis should be performed according to guidelines that safeguard the subjects’ welfare. The diagnostic process is only recommended for patients over 18 years old with symptoms suggesting SCA, and a minimum risk of 50%. Genetic counselling programmes must be available in all centres that offer presymptomatic diagnosis of SCA (AU)