Evaporative destabilization of a salt crust with branched pattern formation.

The impact of salt crust formation over porous media on water evaporation is an important issue in relation with the water cycle, agriculture, building sciences and more. The salt crust is not a simple accumulation of salt crystals at the porous medium surface but undergoes complex dynamics with possible air gap formation between the crust and the porous medium surface. We report on experiments that allow to identify various crust evolution regimes depending on the competition between evaporation and vapor condensation. The various regimes are summarized in a diagram. We focus on the regime where dissolution-precipitation processes lead to the upward displacement of the salt crust and the generation of a branched pattern. It is shown that the branched pattern results from the crust upper surface destabilization whereas the crust lower surface remains essentially flat. We show that the resulting branched efflorescence salt crust is heterogeneous with a greater porosity in the salt fingers. This leads to the preferential drying of the salt fingers followed by a period in which the crust morphology change only occurs in the salt crust lower region. The salt crust eventually tends toward a frozen state where no visible change occurs in the salt crust morphology, but without blocking the evaporation. These findings provide in-depth insights into the salt crust dynamics and pave the way for the better understanding of the impact of efflorescence salt crusts on evaporation and the development of predictive models.

Representación gráfica del aporte vascular intraóseo y extraóseo del astrágalo. Anatomía ilustrada / Graphic Representation of Intraosseous and Extraosseous Talus Blood Supply. Illustrated Anatomy

Introducción: La anatomía vascular del astrágalo ha sido motivo de investigación por parte de muchos autores, la complejidad de su análisis ha llevado a que no siempre sea fácil de comprender. Sus características anatómicas hacen que algunas áreas sean más susceptibles de sufrir daños y compromisos vasculares tras lesiones traumáticas. El objetivo de este estudio es describir la vascularización del astrágalo, tanto a nivel intraóseo como extraóseo, para obtener una representación gráfica que permita fácilmente conocer su red de irrigación vascular. Material y métodos: Se han realizado las disecciones y los análisis de 19 piezas anatómicas de cadáver humano. Quince de esas piezas se han seccionado en diferentes planos, y se han preparado utilizando la técnica de Spalteholz modificada con inyección de látex con tinta azul y negra para visualizar la red vascular. Además, el estudio se ha complementado con una revisión bibliográfica exhaustiva sobre el tema. Resultados: Los hallazgos han permitido concluir que la arteria tibial posterior aporta la irrigación más importante al cuello y cuerpo del astrágalo a través de la arteria del canal tarsiano y la rama deltoidea. La arteria tibial anterior se divide en la arteria dorsal del pie para la cabeza y el cuello, y la arteria tarsal lateral que a través de las anastomosis origina la arteria del seno del tarso. La arteria peronea perforante, procedente de la arteria peronea, crea una anastomosis intraósea para el cuerpo y el proceso posterior. Conclusión: Los resultados obtenidos han permitido elaborar una representación ilustrada de las áreas de irrigación propias y comunes, que permite comprender de forma gráfica y sencilla la vascularización intraósea y extraósea del astrágalo.(AU)

Background: The vascular anatomy of the talus attracts intense research being not always easy to understand. The high intraosseous variability together with the anatomical characteristics makes some areas of the talus more prone to vascular compromise. The aim of this study is to describe the vascularization of the talus, both intraosseous and extraosseous. Material and methods: From the literature reviewed, we have developed a graphic scheme that allows easy observation of the irrigation distribution. To this end, nineteen anatomical dissections of human cadaveric feet have been carried out. Fifteen fresh-frozen slices have been cut in different planes and prepared using the modified Spalteholz technique and latex injection with blue and black ink to visualize the vascular network. In addition, the study has been complemented with a comprehensive literature review on this subject. Results: The findings allowed us to conclude that the posterior tibial artery provides the most important blood supply to the neck and body of the talus through the tarsal canal artery and the deltoid branch. The anterior tibial artery splits in the dorsal pedis artery, for the head and neck, and the lateral tarsal artery which throughout anastomoses breeds the tarsal sinus artery. The perforating peroneal artery branches out from the peroneal artery, creating an intraosseous anastomosis for the body and the posterior process. Conclusion: The results obtained have contributed to develop a graphical representation that we present in this study, which allows a simple understanding of the intraosseus and extraosseus vascularization of the talus.(AU)

[Translated article] Graphic representation of intraosseous and extraosseous talus blood supply. Illustrated anatomy / Representación gráfica del aporte vascular intraóseo y extraóseo del astrágalo. Anatomía Ilustrada

Introducción: La anatomía vascular del astrágalo ha sido motivo de investigación por parte de muchos autores, la complejidad de su análisis ha llevado a que no siempre sea fácil de comprender. Sus características anatómicas hacen que algunas áreas sean más susceptibles de sufrir daños y compromisos vasculares tras lesiones traumáticas. El objetivo de este estudio es describir la vascularización del astrágalo, tanto a nivel intraóseo como extraóseo, para obtener una representación gráfica que permita fácilmente conocer su red de irrigación vascular. Material y métodos: Se han realizado las disecciones y los análisis de 19 piezas anatómicas de cadáver humano. Quince de esas piezas se han seccionado en diferentes planos, y se han preparado utilizando la técnica de Spalteholz modificada con inyección de látex con tinta azul y negra para visualizar la red vascular. Además, el estudio se ha complementado con una revisión bibliográfica exhaustiva sobre el tema. Resultados: Los hallazgos han permitido concluir que la arteria tibial posterior aporta la irrigación más importante al cuello y cuerpo del astrágalo a través de la arteria del canal tarsiano y la rama deltoidea. La arteria tibial anterior se divide en la arteria dorsal del pie para la cabeza y el cuello, y la arteria tarsal lateral que a través de las anastomosis origina la arteria del seno del tarso. La arteria peronea perforante, procedente de la arteria peronea, crea una anastomosis intraósea para el cuerpo y el proceso posterior. Conclusión: Los resultados obtenidos han permitido elaborar una representación ilustrada de las áreas de irrigación propias y comunes, que permite comprender de forma gráfica y sencilla la vascularización intraósea y extraósea del astrágalo.(AU)

Background: The vascular anatomy of the talus attracts intense research being not always easy to understand. The high intraosseous variability together with the anatomical characteristics makes some areas of the talus more prone to vascular compromise. The aim of this study is to describe the vascularization of the talus, both intraosseous and extraosseous. Material and methods: From the literature reviewed, we have developed a graphic scheme that allows easy observation of the irrigation distribution. To this end, nineteen anatomical dissections of human cadaveric feet have been carried out. Fifteen fresh-frozen slices have been cut in different planes and prepared using the modified Spalteholz technique and latex injection with blue and black ink to visualize the vascular network. In addition, the study has been complemented with a comprehensive literature review on this subject. Results: The findings allowed us to conclude that the posterior tibial artery provides the most important blood supply to the neck and body of the talus through the tarsal canal artery and the deltoid branch. The anterior tibial artery splits in the dorsal pedis artery, for the head and neck, and the lateral tarsal artery which throughout anastomoses breeds the tarsal sinus artery. The perforating peroneal artery branches out from the peroneal artery, creating an intraosseous anastomosis for the body and the posterior process. Conclusion: The results obtained have contributed to develop a graphical representation that we present in this study, which allows a simple understanding of the intraosseus and extraosseus vascularization of the talus.(AU)

[Translated article] Graphic representation of intraosseous and extraosseous talus blood supply. Illustrated anatomy.

BACKGROUND: The vascular anatomy of the talus attracts intense research being not always easy to understand. The high intraosseous variability together with the anatomical characteristics makes some areas of the talus more prone to vascular compromise. The aim of this study is to describe the vascularisation of the talus, both intraosseous and extraosseous. MATERIAL AND METHODS: From the literature reviewed, we have developed a graphic scheme that allows easy observation of the irrigation distribution. To this end, nineteen anatomical dissections of human cadaveric feet have been carried out. Fifteen fresh-frozen slices have been cut in different planes and prepared using the modified Spalteholz technique and latex injection with blue and black ink to visualise the vascular network. In addition, the study has been complemented with a comprehensive literature review on this subject. RESULTS: The findings allowed us to conclude that the posterior tibial artery provides the most important blood supply to the neck and body of the talus through the tarsal canal artery and the deltoid branch. The anterior tibial artery splits in the dorsal pedis artery, for the head and neck, and the lateral tarsal artery which throughout anastomoses breeds the tarsal sinus artery. The perforating peroneal artery branches out from the peroneal artery, creating an intraosseous anastomosis for the body and the posterior process. CONCLUSION: The results obtained have contributed to develop a graphical representation that we present in this study, which allows a simple understanding of the intraosseus and extraosseus vascularisation of the talus.

Detachment mechanism and reduced evaporation of an evaporative NaCl salt crust.

Salt crusts forming at the surface of a porous medium are commonly observed in nature as well as on building materials and pieces of our cultural heritage where they represent a risk for the supporting substrate integrity. Previous research indicates that the salt crust can detach from the porous substrate and severely reduces the evaporation. However, the current understanding of the detachment mechanisms and the reduced evaporation is very limited. In the present experiment, we evidence dissolution-precipitation processes as key mechanisms in the detachment process. We also show that the crust remains wet and the observed reduced evaporation is explained by the formation of tiny pores in the nanometer range and the Kelvin effect. The resulting crust permeability is very low. Combined with previous results, this shows that the crust permeability is highly dependent on the crust formation conditions. More generally, salt structures in a water vapor concentration gradient are shown to be self-propelled systems capable to carry small objects such as, for instance, soil particles. Our study has significance for understanding the impact of salt crusts on evaporation and the associated important phenomena, such as soil salinization and porous material degradation inherent to salt crystallization.

Effectiveness of a Weight-Loss Intervention in Preventing Frailty and Functional Decline in Community-Dwelling Obese Older People. A Randomized Controlled Trial.

BACKGROUND: Obesity is a risk factor for frailty and muscle weakness, so weight loss in obese older adults may prevent frailty and functional decline. OBJECTIVE: To assess the safety and efficacy of a multimodal weight-loss intervention in improving functional performance and reducing frailty risk in obese older adults. DESIGN: Randomized controlled trial with 2 parallel arms. SETTING AND PARTICIPANTS: Community-dwelling obese adults aged 65-75 years with body mass index (BMI) 30-39 kg/m2. INTERVENTION: 6-month multimodal intervention based on diet and a physical activity program. CONTROL GROUP: Usual care. Main and secondary outcome measures: Frailty (Fried criteria) rate and functional performance at 6, 12, and 24 months of follow-up, respectively. Intermediate outcome measures: Weight loss, body composition changes, and metabolic and inflammatory biomarker changes. RESULTS: N=305. The study intervention increased gait speed at 12 and 24 months of follow-up, but had no significant effect on frailty prevention. It was effective in reducing weight, BMI, fat mass, interleukin 6, and insulin resistance and improving self-reported quality of life. CONCLUSIONS: The study intervention was not demonstrated to be effective in preventing frailty in obese people aged 65-75 years at 24 months of follow-up. However, it allowed weight loss and a reduction in inflammatory and insulin resistance markers, which could have a long-term effect on frailty that requires further research.

Graphic Representation of Intraosseous and Extraosseous Talus Blood Supply. Illustrated Anatomy. / Representación gráfica del aporte vascular intraóseo y extraóseo del astrágalo. Anatomía ilustrada.

BACKGROUND: The vascular anatomy of the talus attracts intense research being not always easy to understand. The high intraosseous variability together with the anatomical characteristics makes some areas of the talus more prone to vascular compromise. The aim of this study is to describe the vascularization of the talus, both intraosseous and extraosseous. MATERIAL AND METHODS: From the literature reviewed, we have developed a graphic scheme that allows easy observation of the irrigation distribution. To this end, nineteen anatomical dissections of human cadaveric feet have been carried out. Fifteen fresh-frozen slices have been cut in different planes and prepared using the modified Spalteholz technique and latex injection with blue and black ink to visualize the vascular network. In addition, the study has been complemented with a comprehensive literature review on this subject. RESULTS: The findings allowed us to conclude that the posterior tibial artery provides the most important blood supply to the neck and body of the talus through the tarsal canal artery and the deltoid branch. The anterior tibial artery splits in the dorsal pedis artery, for the head and neck, and the lateral tarsal artery which throughout anastomoses breeds the tarsal sinus artery. The perforating peroneal artery branches out from the peroneal artery, creating an intraosseous anastomosis for the body and the posterior process. CONCLUSION: The results obtained have contributed to develop a graphical representation that we present in this study, which allows a simple understanding of the intraosseus and extraosseus vascularization of the talus.

Prevalence, incidence and risk factors for foot pressure ulcers in hospitalized elderly patients. An observational and prospective study.

BACKGROUND: Incidence and clinical characteristics of foot pressure ulcers (FPU) in hospitalized elderly patients are not well known. The aim of the study was to determine the incidence of FPU during hospitalization, to describe main FPU characteristics and to assess main risk factors for FPU in hospitalised elderly subjects. METHODOLOGY: An observational prospective study was performed in which patients 65 years or older admitted to Vascular Surgery, Orthopaedic or Geriatric departments were followed from admission to discharge. Trained nurses evaluated all recruited patients on a daily basis for possible FPU. Main characteristics of the patient (age, sex and co-morbidities) and the ulcer (location, grade) were registered. RESULTS: 299 patients were recruited (62.2% women, mean age 82.3 years, mean number of co-morbidities 2.8). Prevalence of FPU was 30.1% at admission and 73.9% at discharge. Incidence of FPU during hospitalization was 9.5 new FPU/100 person-day. 97.0% of the new FPU were grade 1 (erythema) and the most common locations were in the heel (57.6%), the external lateral part of the foot (13.1%), and the hallux of the fist toe (11.8%). Apart from immobility, main risk factors for FPU are age, geriatric residence origin and not able to outdoor life. CONCLUSIONS: FPU has a high incidence among hospitalised elderly patients; most of them are grade 1 and located in the heel. More attention must be paid in the prevention of pressure ulcers in hospitalized frail subjects.

Current functioning of cardio-oncology units in Spain.

PURPOSE: The aim of the current survey was to describe the functioning of cardio-oncology (C-O) units in Spain. METHODS: All members of the Spanish Society of Cardiology pertaining to scientific communities related to C-O received questionnaires on the existence of specific programs at their institutions. A second, more extensive questionnaire was sent to the centers which reported C-O organization. RESULTS: We identified 56 centers with C-O programs of which 32 (62.5%) replied to the extended questionnaire. 28% of all centers reported having a multidisciplinary unit involving specialists in several areas. More than 80% of the centers developed surveillance protocols locally adapted which included advanced echocardiographic techniques (68%) or troponin (82%). CONCLUSIONS: The number of institutions with C-O programs is still limited but higher than reported in a survey in 2017. Development of multidisciplinary units of C-O should be promoted to improve the cardiovascular health of cancer patients.

The IL-2RG R328X nonsense mutation allows partial STAT-5 phosphorylation and defines a critical region involved in the leaky-SCID phenotype.

In addition to their detection in typical X-linked severe combined immunodeficiency, hypomorphic mutations in the interleukin (IL)-2 receptor common gamma chain gene (IL2RG) have been described in patients with atypical clinical and immunological phenotypes. In this leaky clinical phenotype the diagnosis is often delayed, limiting prompt therapy in these patients. Here, we report the biochemical and functional characterization of a nonsense mutation in exon 8 (p.R328X) of IL2RG in two siblings: a 4-year-old boy with lethal Epstein-Barr virus-related lymphoma and his asymptomatic 8-month-old brother with a Tlow B+ natural killer (NK)+ immunophenotype, dysgammaglobulinemia, abnormal lymphocyte proliferation and reduced levels of T cell receptor excision circles. After confirming normal IL-2RG expression (CD132) on T lymphocytes, signal transducer and activator of transcription-1 (STAT-5) phosphorylation was examined to evaluate the functionality of the common gamma chain (γc ), which showed partially preserved function. Co-immunoprecipitation experiments were performed to assess the interaction capacity of the R328X mutant with Janus kinase (JAK)3, concluding that R328X impairs JAK3 binding to γc . Here, we describe how the R328X mutation in IL-2RG may allow partial phosphorylation of STAT-5 through a JAK3-independent pathway. We identified a region of three amino acids in the γc intracellular domain that may be critical for receptor stabilization and allow this alternative signaling. Identification of the functional consequences of pathogenic IL2RG variants at the cellular level is important to enable clearer understanding of partial defects leading to leaky phenotypes.

Dissolution-precipitation-driven upward migration of a salt crust.

Salt crusts forming at the surface of a porous medium can dynamically evolve with crust displacements leading to the formations of domes and blisters or simply to the upward migration of the crust. However, the mechanisms explaining the displacements are unclear. It has been conjectured that they could be related to dissolution-precipitation phenomena and/or to mechanical effects associated with the concept of crystallization pressure. We present a simple experiment where the crust upward migration is significant and can be entirely explained from the consideration of dissolution-precipitation phenomena. Equations governing the crust displacement are derived, leading to quite good agreement with the experimental results.

Total Body Water and Intracellular Water Relationships with Muscle Strength, Frailty and Functional Performance in an Elderly Population.

BACKGROUND: As a person ages, total body water (TBW), intracellular water (ICW), muscle mass and muscle strength tend to decline. The decline in ICW may reflect losses in the number of muscle cells but may also be responsible for less hydrated muscle cells. AIM: To assess whether TBW and ICW are associated with muscle strength, functional performance and frailty in an aged population, independently of muscle mass. METHODOLOGY: Design: An observational cross-sectional study of community-dwelling individuals aged 75 years and older. TBW, ICW, fat mass, lean mass and muscle mass were assessed by bioelectrical impedance analysis, frailty status was measured according to Fried criteria, handgrip strength was measured using the hand-held JAMAR dynamometer, and functional performance was measured according to the Barthel index and gait speed. RESULTS: A total of 324 subjects were recruited (mean age 80.1 years, 47.5% women). TBW and ICW were closely correlated with muscle mass in both sexes. ICW was also associated with Barthel score, gait speed and frailty in both sexes and with handgrip in men. Considerable variability in ICW was observed for the same muscle mass. Multivariate analysis showed a positive effect of ICW on handgrip, functional performance and gait speed and a protective effect of ICW on frailty, independently of age, sex, body mass index and number of comorbidities. CONCLUSIONS: In elderly individuals with similar muscle mass, those with higher ICW had a better functional performance and a lower frailty risk, suggesting a protective effect of cell hydration, independently of muscle mass.

Agregado trióxido mineral y cemento pórtland expuestos a irrigantes endodóncicos: pH, conductividad y solubilidad / Mineral trioxide aggregate and portland cement exposed to endodontic irrigants: pH, conductivity, and solubility

Objetivo: El objetivo de este estudio fue determinar, el pH, la conductividad y la solubilidad al someter el agregado trióxido mineral (MTA) y el cemento Pórtland (CP) a diferentes irrigantes utilizados en endodoncia. Material y Métodos: Se estudiaron un total de 210 muestras, 105 de cemento ProRoot MTA(R) blanco y 105 de CP blanco. Se seleccionaron los siguientes irrigantes: hipoclorito sódico al 2,5% y al 5%, ácido cítrico al 10% y al 20%, clorhexidina al 2%, EDTA al 17%, y suero fisiológico como control. Se expusieron 15 muestras de MTA y 15 de CP a cada tipo de irrigante. Se midieron los resultados a 1, 5, 15, 30 y 60 minutos. Resultados: La mayoría de cambios del pH y la conductividad fueron de pequeña magnitud, aunque estadísticamente significativos. Destacan la alcalinización del suero fisiológico y la acidificación del hipoclorito sódico. Con MTA disminuye la conductividad en hipoclorito sódico y aumenta la conductividad en EDTA. Con CP hubo una mayor pérdida de conductividad del hipoclorito sódico y del ácido cítrico. Todas las muestras disminuyeron el peso considerablemente después de la exposición a cualquiera de los irrigantes, y en general ésta fue mayor para el CP que el MTA. Conclusiones: El contacto del material de reparación con los irrigantes utilizados habitualmente en endodoncia altera poco el pH y la conductividad pero aumenta marcadamente su solubilidad. Estos cambios afectan menos al MTA que al CP

Objective. The aim of this study was to determine changes to pH, conductivity, and solubility when mineral trioxide aggregate (MTA) and Portland cement (PC) are exposed to different endodontic irrigants. Methods. The study included a total of 210 samples, 105 white ProRoot MTA® cement and 105 white PC cement. The following irrigants were tested: 2.5% and 5% sodium hypochlorite, 10% and 20% citric acid, 2% chlorhexidine, 17% ethylenediamine tetra-acetic acid (EDTA), and physiological serum as a control. Fifteen samples of each material were exposed to each irrigant. PH, conductivity, and solubility were measured at baseline and after 1, 5, 15, 30 and 60 minutes exposure to irrigants. Results. Most changes in pH and conductivity were of small magnitude, although statistically significant. For MTA and PC physical serum produced alkalinization, while sodium hypochlorite produced acidification. MTA lost conductivity when exposed to sodium hypochlorite but this increased with exposure to EDTA. PC underwent greater losses of conductivity when exposed to sodium hypochlorite and citric acid. All samples decreased in weight significantly after exposure to any of the irrigants, and the loss was generally greater for PC than MTA. Conclusions. When repair materials are exposed to the irrigants normally used in endodontics, pH levels and conductivity alter slightly, while solubility increases markedly. These effects were greater for PC than MTA

Rugosidad superficial del agregado de trióxido mineral y el cemento pórtland expuestos a irrigantes endodóncicos / Surface roughness of the mineral trioxide aggregate and Portland cement exposed to endodontic irrigants

Objetivo: El propósito de este estudio fue determinar la rugosidad superficial, al someter al agregado de trióxido mineral (MTA) y al cemento Pórtland (CP) a diferentes irrigantes utilizados en endodoncia. Material y Métodos: Se estudiaron un total de 210 muestras, 105 de cemento ProRoot MTA® blanco y 105 de CP blanco. Se seleccionaron los siguientes irrigantes: hipoclorito sódico al 2,5% y al 5%, ácido cítrico al 10% y al 20%, clorhexidina al 2%, EDTA al 17%, y suero fisiológico como control. Se expusieron 15 muestras de cada cemento por cada tipo de irrigante durante 15 minutos. El estudio de la rugosidad superficial se hizo con el microscopio Leica DCM 3D que permite una perfilometría con tecnología dual confocal e interferométrica. Se evaluó la rugosidad media (Ra), el valor cuadrático medio (RMS) y la profundidad de rugosidad máxima (PV) al inicio y a los 15 minutos de la inmersión de las muestras. Resultados: El CP aumentó significativamente la rugosidad en los parámetros Ra y RMS tras la irrigación con hipoclorito al 2,5%, ácido cítrico al 10% y al 20%, y suero fisiológico. En términos de PV el CP solo aumentó la rugosidad tras la irrigación con ácido cítrico al 20% y suero fisiológico. El MTA no mostró cambios significativos respecto a la rugosidad Ra, RMS y PV con ninguno de los irrigantes. Conclusiones: La rugosidad superficial del CP puede modificarse por la exposición a alguno de los irrigantes utilizados en endodoncia, mientras que la rugosidad del MTA no se modifica significativamente

Objectives: This study set out to determine changes to surface roughness when mineral trioxide aggregate (MTA) and Portland cement (PC) are exposed to the different irrigants used in endodontics. Material and Methods: The study included a total of 210 samples, 105 white ProRoot MTA® cement and 105 white PC cement. The following irrigants were tested: 2.5% and 5% sodium hypochlorite, 10% and 20% citric acid, 2% chlorhexidine, 17% ethylenediamine tetra-acetic acid (EDTA), and physiological serum as a control. Fifteen samples of each material were exposed to each irrigant for 15 minutes. Surface roughness evaluation was performed using a Leica DCM 3D microscope for dual system (confocal and interferometric) profilometry. Mean roughness (Ra), root mean square (RMS) and maximum roughness depth (PV) were evaluated before and after 15 minutes sample immersion in each irrigant. Results: PC significantly increased roughness for Ra and RMS parameters after irrigation with 2.5% sodium hypochlorite, 10% and 20% citric acid, and physiological serum. PC underwent an increase in the PV parameter after immersion in 20% citric acid and physiological serum. MTA did not show significant changes in Ra, RMS or PV with any of the irrigants. Significance. The surface roughness of PC may be modified by exposure to some of the irrigants used in endodontics, while the roughness of MTA is not modified significantly

Single layer porous media with entrapped minerals for microscale studies of multiphase flow.

The behaviour of minerals (i.e. salts) such as sodium chloride and calcite in porous media is very important in various applications such as weathering of artworks, oil recovery and CO2 sequestration. We report a novel method for manufacturing single layer porous media in which minerals can be entrapped in a controlled way in order to study their dissolution and recrystallization. In addition, our manufacturing method is a versatile tool for creating monomodal, bimodal or multimodal pore size microporous media with controlled porosity ranging from 25% to 50%. These micromodels allow multiphase flows to be quantitatively studied with different microscopy techniques and can serve to validate numerical models that can subsequently be extended to the 3D situation where visualization is experimentally difficult. As an example of their use, deliquescence (dissolution by moisture absorption) of entrapped NaCl crystals is studied; our results show that the invasion of the resulting salt solution is controlled by the capillary pressure within the porous network. For hydrophilic porous media, the liquid preferentially invades the small pores whereas in a hydrophobic network the large pores are filled. Consequently, after several deliquescence/drying cycles in the hydrophilic system, the salt is transported towards the outside of the porous network via small pores; in hydrophobic micromodels, no salt migration is observed. Numerical simulations based on the characteristics of our single layer pore network agree very well with the experimental results and give more insight into the dynamics of salt transport through porous media.

Ion Transport and Precipitation Kinetics as Key Aspects of Stress Generation on Pore Walls Induced by Salt Crystallization.

The stress generation on pore walls due to the growth of a sodium chloride crystal in a confined aqueous solution is studied from evaporation experiments in microfluidic channels in conjunction with numerical computations of crystal growth. The study indicates that the stress buildup on the pore walls is a highly transient process taking place over a very short period of time (in less than 1 s in our experiments). The analysis makes clear that what matters for the stress generation is not the maximum supersaturation at the onset of the crystal growth but the supersaturation at the interface between the solution and the crystal when the latter is about to be confined between the pore walls. The stress generation is summarized in a simple stress diagram involving the pore aspect ratio and the Damkhöler number characterizing the competition between the precipitation reaction kinetics and the ion transport towards the growing crystal. This opens up the route for a better understanding of the damage of porous materials induced by salt crystallization, an important issue in Earth sciences, reservoir engineering, and civil engineering.

Effectiveness of an intervention to prevent frailty in pre-frail community-dwelling older people consulting in primary care: a randomised controlled trial.

Background: evidence on the effectiveness of interventions to prevent frailty is scarce. Objective: to assess the effect of an intervention in preventing frailty progression in pre-frail older people. Study design: a randomised, open label, controlled trial with two parallel arms. Population: community-dwelling pre-frail older people (≥70 years) consulting in primary care. Intervention: nutritional assessment (and derivation to a Nutritional Unit for usual care in the event of nutritional risk) and a physical activity programme including aerobic exercise and a set of mixed strengthening, balance and coordination exercises. Control group: patients receiving the usual care. Main outcome measure: prevalence of frailty (Fried criteria) at 12 months. Secondary outcomes measures: functional capacity (Barthel index), falls and nutritional status (Short-Form Mini Nutritional Assessment) on follow-up at 12 months. Results: one hundred and seventy-two participants were recruited and randomised (mean age: 78.3 years; mean number of Fried criteria: 1.45). Thirty-nine participants (22.6%) were dropped out during the study. At follow-up, 4.9% of the intervention group and 15.3% of the control group had evolved to frailty, for a crude odds ratio (OR) of 0.29 (95% confidence interval [CI]: 0.08-1.08; P = 0.052) and an adjusted (by age, gender and number of co-morbidities) OR of 0.19 (95% CI: 0.04-0.95; P = 0.044). Intervention group showed a higher outdoors walking hour per day (0.97 versus 0.73; P = 0.019) but no difference was observed in muscle strength, gait speed or other functional indicators. Conclusion: an intervention focused on physical exercise and maintaining good nutritional status may be effective in preventing frailty in community-dwelling pre-frail older individuals. ClinicalTrials.gov identifier: NCT02138968.

A comparison of "flat fielding" techniques for x-ray framing cameras.

Gain can vary across the active area of an x-ray framing camera by a factor of 4 (or more!) due to the voltage loss and dispersion associated with pulse transmission in a microstripline-coated microchannel plate. In order to make quantitative measurements, it is consequently important to measure the gain variation ("flat field"). Moreover, because of electromagnetic cross talk, gain variation depends on specific operational parameters, and ideally a flat field would be obtained at all operating conditions. As part of a collaboration between Lawrence Livermore National Laboratory's National Ignition Facility and the Commissariat à l'Énergie Atomique, we have been able to evaluate the consistency of three different methods of measuring x-ray flat fields. By applying all three methods to a single camera, we are able to isolate performance from method. Here we report the consistency of the methods and discuss systematic issues with the implementation and analysis of each.

Clinical and Functional Characterization of Pre-frailty among Elderly Patients Consulting Primary Care Centres.

BACKGROUND: Characterization of the main features of pre-frailty may contribute to better understanding the mechanisms involved in the development of frailty. OBJECTIVE: To characterize the pre-frail population consulting in primary care centres in Mataró (Catalonia, Spain), to describe the Fried's frailty criteria for this population and to identify the main associated factors. DESIGN: Cross-sectional study. SETTING: Three primary care centres in Catalonia. PARTICIPANTS: Pre-frail subjects recruited from among persons aged 70 years and older consulting primary care centres and screened for frailty according to Fried's criteria. MEASUREMENTS: Clinical, nutritional and functional data. RESULTS: Frailty prevalence of 31.0% and pre-frailty prevalence of 49.0% were observed. Comorbidity was not especially frequent among elderly individuals classified as pre-frail (except for diabetes with 35.8% prevalence). Functional status and nutritional status were both reasonably satisfactory in pre-frail subjects with mean Barthel score of 98 points and 91% classified as well nourished. Among pre-frail subjects, 35% were obese (body mass index>30); 75% reported pain; 12% had an accidental fall in the previous three months; and the mean number of medications ingested was 6.2. Weakness was the most prevalent frailty criterion (70%), followed by slowness (30%). Weakness was associated with age in men and with pain in women. Poor physical activity was associated with pain. CONCLUSIONS: Pre-frailty is very common among elderly subjects consulting primary care centres. Weakness, slowness, diabetes, pain and polypharmacy should alert healthcare professionals to the onset of a frailty process.

Iodine status and thyroid function among Spanish schoolchildren aged 6-7 years: the Tirokid study.

I deficiency is still a worldwide public health problem, with children being especially vulnerable. No nationwide study had been conducted to assess the I status of Spanish children, and thus an observational, multicentre and cross-sectional study was conducted in Spain to assess the I status and thyroid function in schoolchildren aged 6-7 years. The median urinary I (UI) and thyroid-stimulating hormone (TSH) levels in whole blood were used to assess the I status and thyroid function, respectively. A FFQ was used to determine the consumption of I-rich foods. A total of 1981 schoolchildren (52 % male) were included. The median UI was 173 µg/l, and 17·9 % of children showed UI<100 µg/l. The median UI was higher in males (180·8 v. 153·6 µg/l; P<0·001). Iodised salt (IS) intake at home was 69·8 %. IS consumption and intakes of ≥2 glasses of milk or 1 cup of yogurt/d were associated with significantly higher median UI. Median TSH was 0·90 mU/l and was higher in females (0·98 v. 0·83; P<0·001). In total, 0·5 % of children had known hypothyroidism (derived from the questionnaire) and 7·6 % had TSH levels above reference values. Median TSH was higher in schoolchildren with family history of hypothyroidism. I intake was adequate in Spanish schoolchildren. However, no correlation was found between TSH and median UI in any geographical area. The prevalence of TSH above reference values was high and its association with thyroid autoimmunity should be determined. Further assessment of thyroid autoimmunity in Spanish schoolchildren is desirable.