Editorial: Rising stars in exercise physiology

[Extract] Physical exercise has been recognized as essential for human health and evolution for thousands of years, beginning with the ancient cultures. Hippocrates, Plato, Aristotle, and the Roman physician Galen were the earliest recorded and most well-known promoters of the beneficial effects of physical exercise. Since these times, several dedicated laboratories worldwide have been established, with many researchers conducting numerous investigations related to exercise physiology; nevertheless, a cornerstone of all laboratories is the development of new and novel researchers. These talented and emerging researchers have been necessary for our understanding of exercise physiology to have reached where we are today (and where we will be in the future). Given the evolution of exercise physiology, the field has incorporated a range of basic to applied scientific investigations and a range of end-users (e.g., researchers, athletes, coaches, physiologists, and clinical/public health professionals) who will benefit from these new advances in exercise physiology

Nanostructured supramolecular hydrogels: Towards the topical treatment of Psoriasis and other skin diseases

Supramolecular hydrogels were synthesized using a bis-imidazolium based amphiphile, and incorporating chemically diverse drugs, such as the cytostatics gemcitabine hydrochloride and methotrexate sodium salt, the immunosuppressive drug tacrolimus, as well as the corticoid drugs betamethasone 17-valerate and triamcinolone acetonide, and their potential as drug delivery agents in the dermal treatment of Psoriasis was evaluated. The rheological behavior of gels was studied, showing in all cases suitable viscoelastic properties for topical drug delivery. Scanning electron microscopy (SEM) shows that the drugs included have a great influence on the gel morphology at the microscopic level, as the incorporation of gemcitabine hydrochloride leads to slightly thicker fibers, the incorporation of tacrolimus induces flocculation and spherical precipitates, and the incorporation of methotrexate forms curled fibers. 1H NMR spectroscopy experiments show that these drugs not only remain dissolved at the interstitial space, but up to 72% of either gemcitabine or methotrexate, and up to 38% of tacrolimus, is retained within the gel fibers in gels formed with a 1:1 gelator:drug molar ratio. This unique fiber incorporation not only protects the drug from degradation, but also importantly induces a Two Phase Exponential drug release, where the first phase corresponds to the drug dissolved in the interstitial space, while the second phase corresponds to the drug exiting from the gel fibers, and where the speed in each phase is in accordance with the physicochemical properties of the drugs, opening perspectives for controlled delivery. Skin permeation ex vivo tests show how these gels successfully promote the drug permeation and retention inside the skin for reaching their therapeutic target, while in vivo experiments demonstrate that they decrease the hyperplasia and reduce the macroscopic tissue damage typically observed in psoriatic skin, significantly more than the drugs in solution. All these characteristics, beside the spontaneous and easy preparation (room temperature and soft stirring), make these gels a good alternative to other routes of administration for Psoriasis treatment, increasing the drug concentration at the target tissue, and minimizing side effects

Relevance of the Carotid Body Chemoreflex in the Progression of Heart Failure.

Chronic heart failure (CHF) is a global health problem affecting millions of people. Autonomic dysfunction and disordered breathing patterns are commonly observed in patients with CHF, and both are strongly related to poor prognosis and high mortality risk. Tonic activation of carotid body (CB) chemoreceptors contributes to sympathoexcitation and disordered breathing patterns in experimental models of CHF. Recent studies show that ablation of the CB chemoreceptors improves autonomic function and breathing control in CHF and improves survival. These exciting findings indicate that alterations in CB function are critical to the progression of CHF. Therefore, better understanding of the physiology of the CB chemoreflex in CHF could lead to improvements in current treatments and clinical management of patients with CHF characterized by high chemosensitivity. Accordingly, the main focus of this brief review is to summarize current knowledge of CB chemoreflex function in different experimental models of CHF and to comment on their potential translation to treatment of human CHF

Effects of drought ? altered seasonality and low rainfall ? in net ecosystem carbon exchange of three contrasting Mediterranean ecosystems

International audienceDroughts cause reductions in gross primary production (GPP) and also in net ecosystem exchange (NEE), contributing to most of the inter-annual variability in terrestrial carbon sequestration. In seasonally dry climates (Mediterranean) droughts result from reductions in annual rainfall and from changes in rain seasonality. In western Iberia, the hydrological-year (i.e., from October to September) of 2004?2005 was extremely dry, with precipitation 50% below the long-term mean (691 mm in 1961?1990), but 2005?2006 was normal. We compared the carbon fluxes measured by the eddy covariance technique from three contrasting ecosystems in southern Portugal: an evergreen oak woodland (savannah-like) with ca. 21% tree cover; a Mediterranean C3/C4 grassland; and a coppiced eucalyptus plantation. During the dry hydrological-year of 2004?2005, NEE was lowest, the highest sink strength was in the eucalypt plantation (NEE = ?399 g C m ?2 year?1) as compared to the oak woodland (NEE = ?88 g C m ?2 year?1), and the grassland (NEE = +49 g C m ?2 year ?1). The latter was a source of carbon dioxide. The NEE values of the dry year were, however, much lower than those for wetter years, e.g. NEE = ?861 g C m?2 year ?1 in 2002?2003 in the eucalypt plantation. The NEE of the grassland and the oak savannah in the 2005?2006 hydrological-year, with annual precipitation above the long term mean, were ?190 and ?120 g C m ?2 year?1, respectively. All ecosystems studied increased their rain-use efficiency (GPP per unit of rain volume) increased in dry years. In the case of annual vegetation ? grassland and low tree density woodland, however &ndash, rain-use efficiency decreased with severe drought. However, this was more pronounced in the eucalypt plantation due to greater GPP and the use of deep soil water resources. Although both calendar years of 2004 and 2005 had equally low rainfall, the effect of drought on the eucalypt plantation was delayed until the second dry year. This suggests that the effects of water deficits on Mediterranean forests are exacerbated by prolonged droughts when long-term soil water reserves are depleted. The grassland, however, was more vulnerable and responded faster to water deficits. This effect of drought was less pronounced in the oak woodland due to the sparse tree cover

Chandra and XMM-Newton observations of the merging cluster of galaxies PLCK G036.7+14.9

We present Chandra and XMM-Newton observations of PLCK G036.7+14.9 from the Chandra-Planck Legacy Program. The high resolution X-ray observations reveal two close subclusters, G036N and G036S, which were not resolved by previous ROSAT, optical, or recent Planck observations. We perform detailed imaging and spectral analyses and use a simplified model to study the kinematics of this system. The basic picture is that PLCK G036.7+14.9 is undergoing a major merger (mass ratio close to unity) between the two massive subclusters, with the merger largely along the line-of-sight and probably at an early stage. G036N hosts a small, moderate cool-core, while G036S has at most a very weak cool-core in the central 40 kpc region. The difference in core cooling times is unlikely to be caused by the ongoing merger disrupting a pre-existing cool-core in G036S. G036N also hosts an unresolved radio source in the center, which may be heating the gas if the radio source is extended. The Planck derived mass is higher than the X-ray measured mass of either subcluster, but is lower than the X-ray measured mass of the whole cluster, due to the fact that Planck does not resolve PLCK G036.7+14.9 into subclusters and interprets it as a single cluster. This mass discrepancy could induce significant bias to the mass function if such previously unresolved systems are common in the Planck cluster sample. High resolution X-ray observations are necessary to identify the fraction of such systems and correct such a bias for the purpose of precision cosmological studies.Comment: 23 pages, 8 figures (low resolution) with additional 12 figures in the Appendix, accepted for publication in Ap

Net ecosystem carbon exchange in three contrasting Mediterranean ecosystems ? the effect of drought

International audienceDroughts reduce gross primary production (GPP) and ecosystem respiration (Reco), contributing to most of the inter-annual variability in terrestrial carbon sequestration. In seasonally dry climates (Mediterranean), droughts result from reductions in annual rainfall and changes in rain seasonality. We compared carbon fluxes measured by the eddy covariance technique in three contrasting ecosystems in southern Portugal: an evergreen oak woodland (savannah-like) with ca.~21% tree crown cover, a grassland dominated by herbaceous annuals and a coppiced short-rotation eucalyptus plantation. During the experimental period (2003?2006) the eucalyptus plantation was always the strongest sink for carbon: net ecosystem exchange rate (NEE) between ?861 and ?399 g C m?2 year?1. The oak woodland and the grassland were much weaker sinks for carbon: NEE varied in the oak woodland between ?140 and ?28 g C m?2 year?1 and in the grassland between ?190 and +49 g C m?2 year?1. The eucalyptus stand had higher GPP and a lower proportion of GPP spent in respiration than the other systems. The higher GPP resulted from high leaf area duration (LAD), as a surrogate for the photosynthetic photon flux density absorbed by the canopy. The eucalyptus had also higher rain use efficiency (GPP per unit of rain volume) and light use efficiency (the daily GPP per unit incident photosynthetic photon flux density) than the other two ecosystems. The effects of a severe drought could be evaluated during the hydrological-year (i.e., from October to September) of 2004?2005. Between October 2004 and June 2005 the precipitation was only 40% of the long-term average. In 2004?2005 all ecosystems had GPP lower than in wetter years and carbon sequestration was strongly restricted (less negative NEE). The grassland was a net source of carbon dioxide (+49 g C m?2 year?1). In the oak woodland a large proportion of GPP resulted from carbon assimilated by its annual vegetation component, which was strongly affected by the shortage of rain in winter. Overall, severe drought affected more GPP than Reco leading to the deterioration of NEE. Although the rain-use efficiency of the eucalyptus plantation increased in the dry year, this was not the case of evergreen oak woodland, which rain-use efficiency was not influenced by drought. Recovery after drought alleviation, i.e., beginning with heavy rain in October 2005, was fully accomplished in 2006 in the oak woodland and grassland, but slow in the eucalyptus plantation

Pacientes hipertensos muestran una mayor respuesta de la frecuencia cardíaca durante el ejercicio progre-sivo en relación con pares adultos normotensos: Proyecto Vascu-Health

Existe información limitada respecto a la respuesta de la frecuencia cardiaca (FC) a partir de fórmulas predictivas y prueba de ejercicio real entre adultos con hipertensión arterial (HTA) y normotensos, así como sobre las similitudes o diferencias vasculares entre muestras de diferente control de la presión arterial. El objetivo de este estudio fue describir y comparar la frecuencia cardiaca durante el ejercicio entre adultos con HTN y normotensos, así como describir parámetros de función endotelial y vasculares. Se realizó un estudio clínico descriptivo con 64 adultos (hombres y mujeres) que fueron divididos en tres grupos: hipertensión arterial (HTN n=26), presión arterial elevada (Ele n=16), o normotensos control (CG n=22). Los participantes se sometieron a una prueba de ejercicio, en la que se midió la FC (variable principal) y parámetros vasculares secundarios (clasificación percentil de la velocidad de la onda del pulso (%ILEPWVba), grosor máximo de la íntima-media carotídea (cIMTmax) y edad arterial entre otras. En la etapa 2 del test (50-100 vatios), el grupo HTN mostró una FC significativamente mayor vs. el grupo GC (+14 latidos/min), y vs. el grupo Ele (+15 latidos/min), ambos p<0,05; y en la etapa 5 (125-250 vatios) vs. el grupo GC (+22 latidos/min; p<0,05). El grupo HTN mostró una clasificación mayor de rigidez arterial %ILEPWVba, y de edad arterial que el grupo NT. En conclusión, los sujetos con HTA presentan una mayor respuesta de la FC durante el ejercicio que los normotensos. Sin embargo, todos los grupos mostraron una mayor HRpredicted en relación con la HRpeak real. Estos resultados se muestran con una clasificación en percentiles superiores de rigidez arterial y una mayor estimación de la edad arterial con relación a adultos normotensos.There is limited information regarding heart rate (HR) response from predictive formulae and actual exercise tests between arterial hypertension (HTN) and normotensive adults, as well as about vascular similarities or differences between samples of different blood pressure control. This study aimed 1) to describe and compare the HR during exercise between HTN and normotensive adults and 2) to describe the endothelial function and related vascular parameters in both groups. A descriptive clinical study was conducted with 64 adults (men and women) who were divided into three groups: arterial hypertension (HTN n=26), elevated blood pressure (Ele n=16), or normotensive control (CG n=22). The participants underwent a incremental cycling exercise test of 5 stages, where HR (primary outcome) was measured, and secondary vascular outcomes (percentile classification of the pulse wave velocity (%ILEPWVba), maximum carotid intima-media thickness (cIMTmax), and arterial age among others were measured. In stage 2 of the test (50-100 watts), the HTN group showed significantly higher HR vs. CG (+14 beats/min; p<0.05) and vs. Ele group (+15 beats/min; p<0.05), and in stage 5 (125-250 watts), HTN group showed vs. CG (+22 beats/min; p<0.05). HTN group showed a higher arterial stiffness by %ILEPWVba classification and arterial age estimation than the CG group. In conclusion, HTN patients reported a higher HR response only in two out of five stages of the Astrand cycling exercise test than normotensive peers. Moreover, all groups showed a higher HRpredicted than real HRpeak obtained from the exercise test. These results are displayed with more altered vascular parameters in the HTN group.This research was funded by Direccion General de In-vestigación, Vicerrectoria de Investigación y Doctorado, Concurso de Ciencias Biomédicas y Clínicas, Universidad Andres Bello 2022 Código N° DI-01-CBC/22”. Also, the main author (C.A.) was funded by the Exercise and Reha-bilitation Sciences Institute, School of Physical Therapy, Faculty of Rehabilitation Sciences, Universidad Andres Bello, Santiago, 7591538, Chile