Carbon dioxide contrast medium for endovascular treatment of ilio-femoral occlusive disease

OBJECTIVES:Compare the use of carbon dioxide contrast medium with iodine contrast medium for the endovascular treatment of ilio-femoral occlusive disease in patients without contraindications to iodine.MATERIALS AND METHODS:From August 2012 to August 2014, 21 consecutive patients with ilio-femoral occlusive disease who were eligible for endovascular treatment and lacked contraindications to either iodine contrast or carbon dioxide were randomized into the carbon dioxide or iodine groups and subjected to ilio-femoral angioplasty.We analyzed the feasibility of the procedures, the surgical and clinical outcomes, the procedure lengths, the endovascular material costs, the contrast costs and the quality of the angiographic images in each group.RESULTS:No conversions to open surgery and no contrast media related complications were noted in either group. A post-operative femoral pulse was present in 88.9% of the iodine group and 80% of the carbon dioxide group. No differences in procedure length, endovascular material cost or renal function variation were noted between the groups. Four patients in the carbon dioxide group required iodine supplementation to complete the procedure. Contrast media expenses were reduced in the carbon dioxide group. Regarding angiographic image quality, 82% of the carbon dioxide images were graded as either good or fair by observers.CONCLUSIONS:The use of carbon dioxide contrast medium is a good option for ilio-femoral angioplasty in patients without contraindications to iodine and is not characterized by differences in endovascular material costs, procedure duration and surgical outcomes. In addition, carbon dioxide has lower contrast expenses compared with iodine

Expression of the nifH gene in diazotrophic bacteria in Eucalyptus urograndis plantations

A large proportion of eucalypt plantations in Brazil are located in areas with low soil fertility. The actions of microorganisms are of great importance for the cycling of nutrients, including nitrogen (N), that are essential for plant metabolism. Denaturing gradient gel electrophoresis (DGGE) was used to monitor and identify the total and active microorganisms involved in the N cycle in both the soil and root systems of a forest of Eucalyptus urograndis with sections that were fertilized with N or unfertilized. Quantitative real-time PCR was used to examine the expression of the nifH gene in N-fixing bacteria present in both the soil and root systems. According to the DGGE analysis, in the total and active populations of N-fixing bacteria, the presence and expression of the nifH gene were influenced by the winter and summer seasons and (or) N fertilization, respectively. DGGE band sequencing from total DNA samples showed that the most abundant group of diazotrophic bacteria belonged to Alphaproteobacteria in both the soil and root systems. Quantitative real-time PCR revealed that nifH expression was higher in the soil samples, especially in those that did not receive N fertilization. The differences in the composition of the total and active diazotrophic populations highlight the importance of evaluating the active populations, because they are effectively responsible for the biogeochemical transformation of N and also control its' availability to plants.Une grande partie des plantations brésiliennes d'eucalyptus sont situées sur des sites peu fertiles. L'action des microorganismes est d'une grande importance dans le recyclage des nutriments, incluant l'azote (N) qui est essentiel au métabolisme des plantes. La technique de DGGE a été employée pour effectuer le suivi et identifier la quantité de microorganismes totaux et actifs impliqués dans le recyclage de N à la fois dans le sol et les systèmes racinaires d'une forêt d'Eucalyptus urograndis comprenant des sections fertilisées à l'azote et d'autres pas. La PCR quantitative en temps réel a été utilisée pour examiner l'expression du gène nifH dans les bactéries fixatrices d'azote présentes à la fois dans le sol et les systèmes racinaires. Selon l'analyse DGGE, chez les populations totales et actives de bactéries fixatrices d'azote, la présence et l'expression du gène nifH étaient respectivement influencées par les saisons hivernale et estivale et/ou par la fertilisation azotée. Le séquençage des bandes de DGGE à partir d'échantillons d'ADN total a démontré que le groupe le plus abondant de bactéries diazotrophiques appartenait aux Alphaprotéobactéries, à la fois dans le sol et les systèmes racinaires. Le PCR quantitatif en temps réel a révélé que l'expression des gènes nifH était plus élevée dans les échantillons de sol, et spécialement dans ceux qui n'avaient pas été fertilisés à l'azote. Les différences dans la composition des populations diazotrophiques totales et actives soulignent l'importance d'évaluer les populations actives puisqu'elles sont effectivement responsables de la transformation biogéochimique de l'azote et qu'elles contrôlent sa disponibilité pour les plantes. [Traduit par la Rédaction]

Randomized trial of radiofrequency ablation versus conventional surgery for superficial venous insufficiency: if you don’t tell, they won’t know

OBJECTIVES: This study compared radiofrequency ablation versus conventional surgery in patients who had not undergone previous treatment for bilateral great saphenous vein insufficiency, with each patient serving as his own control. METHOD: This was a randomized controlled trial that included 18 patients and was carried out between November 2013 and May 2015. Each of the lower limbs of each patient was randomly assigned to undergo either radiofrequency ablation or conventional surgery. Clinical features (hyperpigmentation, hematoma, aesthetics, pain, skin burn, nerve injury, and thrombophlebitis) were evaluated at one week, one month, and six months postoperatively. Hemodynamic assessments (presence of resection or occlusion of the great saphenous vein and recurrent reflux in the sapheno-femoral junction and in the great saphenous vein) were performed at one month, six months, and 12 months postoperatively. The independent observer (a physician not involved in the original operation), patient, and duplex ultrasonographer were not made aware of the treatment done in each case. Clinicaltrials.gov: NCT02588911. RESULTS: Among the clinical variables analyzed, only the aesthetic evaluation by the physicians was significant, with radiofrequency ablation being considered better than conventional surgery (average, 0.91 points higher: standard deviation: 0.31; 95% confidence interval: -1.51, -0.30; p=0.003). However, in our study, we observed primary success rates of 80% for radiofrequency ablation and 100% for conventional surgery. CONCLUSIONS: If the physician is not required to inform the patient as to the technique being performed, the patient will not be able to identify the technique based on the signs and symptoms. Our study revealed that both techniques led to high levels of patient satisfaction, but our results favor the choice of conventional surgery over radiofrequency ablation, as patients who underwent conventional surgery had better hemodynamic assessments

Meanings of social isolation for young Brazilians during the COVID-19 pandemic

Introduction: The COVID-19 pandemic has left a high number of infected and dead in the world, where several social measures have been imposed on the population, especially social isolation. Objective: Given this scenario, based on Vygotsky's socio-historical theory, this original article aimed to identify the meanings of social isolation in the COVID-19 pandemic for Brazilian youth. Method: A survey was carried out, with the participation of 571 young Brazilians, women and men aged between 18 and 25, who answered a sociodemographic questionnaire and the Free Word Association Method (FWAM), analyzed with the help of IRaMuTeQ. Results: The results showed that virtualized socialization is insufficient for the social demand of young people and that their routine was transformed with the insertion of obligations and leisure primarily in the home environment. Still, young people brought their resignifications in this period, in the face of collective responsibility. Conclusions: It is concluded that isolation brought negative consequences on relationships and mental health of young people, but also a greater social awareness

Studies of the mass composition of cosmic rays and proton-proton interaction cross-sections at ultra-high energies with the Pierre Auger Observatory

In this work, we present an estimate of the cosmic-ray mass composition from the distributions of the depth of the shower maximum (Xmax) measured by the fluorescence detector of the Pierre Auger Observatory. We discuss the sensitivity of the mass composition measurements to the uncertainties in the properties of the hadronic interactions, particularly in the predictions of the particle interaction cross-sections. For this purpose, we adjust the fractions of cosmic-ray mass groups to fit the data with Xmax distributions from air shower simulations. We modify the proton-proton cross-sections at ultra-high energies, and the corresponding air shower simulations with rescaled nucleus-air cross-sections are obtained via Glauber theory. We compare the energy-dependent composition of ultra-high-energy cosmic rays obtained for the different extrapolations of the proton-proton cross-sections from low-energy accelerator data

Study of downward Terrestrial Gamma-ray Flashes with the surface detector of the Pierre Auger Observatory

The surface detector (SD) of the Pierre Auger Observatory, consisting of 1660 water-Cherenkov detectors (WCDs), covers 3000 km2 in the Argentinian pampa. Thanks to the high efficiency of WCDs in detecting gamma rays, it represents a unique instrument for studying downward Terrestrial Gamma-ray Flashes (TGFs) over a large area. Peculiar events, likely related to downward TGFs, were detected at the Auger Observatory. Their experimental signature and time evolution are very different from those of a shower produced by an ultrahigh-energy cosmic ray. They happen in coincidence with low thunderclouds and lightning, and their large deposited energy at the ground is compatible with that of a standard downward TGF with the source a few kilometers above the ground. A new trigger algorithm to increase the TGF-like event statistics was installed in the whole array. The study of the performance of the new trigger system during the lightning season is ongoing and will provide a handle to develop improved algorithms to implement in the Auger upgraded electronic boards. The available data sample, even if small, can give important clues about the TGF production models, in particular, the shape of WCD signals. Moreover, the SD allows us to observe more than one point in the TGF beam, providing information on the emission angle

Combined fit to the spectrum and composition data measured by the Pierre Auger Observatory including magnetic horizon effects

The measurements by the Pierre Auger Observatory of the energy spectrum and mass composition of cosmic rays can be interpreted assuming the presence of two extragalactic source populations, one dominating the flux at energies above a few EeV and the other below. To fit the data ignoring magnetic field effects, the high-energy population needs to accelerate a mixture of nuclei with very hard spectra, at odds with the approximate E$^{-2}$ shape expected from diffusive shock acceleration. The presence of turbulent extragalactic magnetic fields in the region between the closest sources and the Earth can significantly modify the observed CR spectrum with respect to that emitted by the sources, reducing the flux of low-rigidity particles that reach the Earth. We here take into account this magnetic horizon effect in the combined fit of the spectrum and shower depth distributions, exploring the possibility that a spectrum for the high-energy population sources with a shape closer to E$^{-2}$ be able to explain the observations