Context.
Gamma-ray binaries are systems that emit nonthermal radiation peaking at energies above 1 MeV. One proposed scenario to explain their emission consists of a pulsar orbiting a massive star, ...with particle acceleration taking place in shocks produced by the interaction of the stellar and pulsar winds.
Aims.
We develop a semi-analytical model of the nonthermal emission of the colliding-wind structure, which includes the dynamical effects of orbital motion. We apply the model to a general case and to LS 5039.
Methods.
The model consists of a one-dimensional emitter, the geometry of which is affected by Coriolis forces owing to orbital motion. Two particle accelerators are considered: one at the two-wind standoff location and the other one at the turnover produced by the Coriolis force. Synchrotron and inverse Compton emission is studied taking into account Doppler boosting and absorption processes associated to the massive star.
Results.
If both accelerators are provided with the same energy budget, most of the radiation comes from the region of the Coriolis turnover and beyond, up to a few orbital separations from the binary system. Significant orbital changes of the nonthermal emission are predicted in all energy bands. The model allows us to reproduce some of the LS 5039 emission features, but not all of them. In particular, the MeV radiation is probably too high to be explained by our model alone, the GeV flux is recovered but not its modulation, and the radio emission beyond the Coriolis turnover is too low. The predicted system inclination is consistent with the presence of a pulsar in the binary.
Conclusions.
The model is quite successful in reproducing the overall nonthermal behavior of LS 5039. Some improvements are suggested to better explain the phenomenology observed in this source, such as accounting for particle reacceleration beyond the Coriolis turnover, unshocked pulsar wind emission, and the three-dimensional extension of the emitter.
La terapia con cánula nasal de alto flujo (CNAF) se ha introducido recientemente en el tratamiento del fallo respiratorio agudo (FRA), siendo una técnica segura, confortable y eficaz que logra ...revertir la hipoxemia en estos pacientes. Es necesario disponer de herramientas que nos permitan detectar precozmente el fallo de este tipo de tratamiento para evitar el incremento de la mortalidad que puede conllevar. El objetivo primario de este estudio ha sido analizar el impacto que la frecuencia respiratoria (FR), la saturación periférica de oxígeno (SpO2), la fracción inspirada de oxígeno (FiO2) y el índice ROX (IROX=SpO2/FiO2/FR) tienen sobre el éxito de la CNAF en los pacientes con FRA hipoxémico. Los objetivos secundarios han sido analizar la estancia y la mortalidad en la UCI y la necesidad de ventilación mecánica (VM).
Se trata de un estudio retrospectivo efectuado en una UCI polivalente del Hospital Comarcal de Montilla (Córdoba). Se incluyeron los pacientes tratados con CNAF por FRA hipoxémico desde enero de 2016 hasta enero de 2018.
Desde enero de 2016 hasta enero de 2018 se trataron 27 pacientes con FRA, de los cuales 19 (70,37%) presentaban FRA hipoxémico. De estos, 15 (78,95%) respondieron bien al tratamiento y 4 (21,05%) fracasaron. A las 2h de tratamiento la FR demostró ser el mejor predictor (área bajo la curva ROC AUROC 0,858; IC95%: 0,63-1,05; p=0,035). La FiO2 y el IROX fueron buenos predictores a las 8h de tratamiento (FiO2: AUROC 0,95; IC95%: 0,85-1,04; p=0,007, e IROX: AUROC 0,967; IC95%: 0,886-1,047; p=0,005). El mejor punto de corte de la FR a la segunda hora fue de 29 respiraciones/min (sensibilidad 75%, especificidad 87%). El mejor punto de corte de la FiO2 a las 8h de tratamiento fue de 0,59 (75% sensibilidad, 93% especificidad). El mejor punto de corte para IROX a las 8h de tratamiento fue de 5,98 (sensibilidad 100%, especificidad 75%). En el modelo de regresión de Cox, una FR<29 respiraciones/min a la segunda hora de tratamiento y una FiO2<0,59 e IROX >5,98 a las 8h de tratamiento se asociaron a un menor riesgo de VM (FR: HR 0,103; IC95%: 0,11-0,99; p=0,05; FiO2: HR 0,053; IC95%: 0,005-0,52; p=0,012, e IROX: HR 0,077; IC95%: 0,008-0,755; p=0,028), respectivamente.
La FR a la segunda hora de tratamiento y la FiO2 e IROX a las 8h de tratamiento fueron los mejores predictores de éxito del CNAF. Una FR<29 respiraciones/min (2.ª hora), una FiO2<0,59 y un IROX>5,98 (8.ª hora) se asociaron a un menor riego de VM.
High-flow nasal cannula (HFNC) therapy is used in the treatment of acute respiratory failure (ARF) and is both safe and effective in reversing hypoxemia. In order to minimize mortality and clinical complications associated to this practice, a series of tools must be developed to allow early detection of failure. The present study was carried out to: (i)examine the impact of respiratory rate (RR), peripheral oxygen saturation (SpO2), ROX index (ROXI=SpO2/FiO2/RR) and oxygen inspired fraction (FiO2) on the success of HFNC in patients with hypoxemic ARF; and (ii)analyze the length of stay and mortality in the ICU, and the need for mechanical ventilation (MV).
A retrospective study was carried out in the medical-surgical ICU of Hospital de Montilla (Córdoba, Spain). Patients diagnosed with hypoxemic ARF and treated with HFNC from January 2016 to January 2018 were included.
Out of 27 patients diagnosed with ARF, 19 (70.37%) had hypoxemic ARF. Fifteen of them (78.95%) responded satisfactorily to HFNC, while four (21.05%) failed. After two hours of treatment, RR proved to be the best predictor of success (area under the ROC curve AUROC 0.858; 95%CI: 0.63-1.05; P=.035). For this parameter, the optimal cutoff point was 29rpm (sensitivity 75%, specificity 87%). After 8hours of treatment, FiO2 and ROXI were reliable predictors of success (FiO2: AUROC 0.95; 95%CI: 0.85-1.04; P=.007 and ROXI: AUROC 0.967; 95%CI: 0.886-1.047; P=.005). In the case of FiO2 the optimal cutoff point was 0.59 (sensitivity 75%, specificity 93%), while the best cutoff point for ROXI was 5.98 (sensitivity 100%, specificity 75%). Using a Cox regression model, we found RR<29rpm after two hours of treatment, and FiO2<0.59 and ROXI>5.98 after 8hours of treatment, to be associated with a lesser risk of MV (RR: HR 0.103; 95%CI: 0.11-0.99; P=.05; FiO2: HR 0.053; 95%CI: 0.005-0.52; P=.012; and ROXI: HR 0.077; 95%CI: 0.008-0.755; P=.028, respectively).
RR after two hours of treatment, and FiO2 and ROXI after 8hours of treatment, were the best predictors of success of HFNC. RR<29rpm, FiO2<0.59 and ROXI>5.98 were associated with a lesser risk of MV.
Fluorescence nanoscopy, or super-resolution microscopy, has become an important tool in cell biological research. However, because of its usually inferior resolution in the depth direction (50–80 nm) ...and rapidly deteriorating resolution in thick samples, its practical biological application has been effectively limited to two dimensions and thin samples. Here, we present the development of whole-cell 4Pi single-molecule switching nanoscopy (W-4PiSMSN), an optical nanoscope that allows imaging of three-dimensional (3D) structures at 10- to 20-nm resolution throughout entire mammalian cells. We demonstrate the wide applicability of W-4PiSMSN across diverse research fields by imaging complex molecular architectures ranging from bacteriophages to nuclear pores, cilia, and synaptonemal complexes in large 3D cellular volumes.
Display omitted
•Whole-cell 4Pi single-molecule switching nanoscopy allows 10- to 20-nm 3D resolution•Refined hardware and new data analysis allow imaging of cells as thick as ∼10 μm•Using structure-averaging, the 3D shape of a bacteriophage can be resolved•Wide applicability across diverse research fields is demonstrated
A new super-resolution microscope opens a window deep into cells to image organelles and subcellular structures spanning large volumes.
Citrus genus is the most important fruit tree crop in the world and lemon is the third most important
Citrus species. Several studies highlighted lemon as an important health-promoting fruit rich in ...phenolic compounds as well as vitamins, minerals, dietary fiber, essential oils and carotenoids. Lemon fruit has a strong commercial value for the fresh products market and food industry. Moreover, lemon productive networks generate high amounts of wastes and by-products that constitute an important source of bioactive compounds with potential for animal feed, manufactured foods, and health care. This review focuses on the phytochemistry and the analytical aspects of lemon compounds as well as on the importance for food industry and the relevance of
Citrus limon for nutrition and health, bringing an overview of what is published on the bioactive compounds of this fruit.
Context. The stellar wind in high-mass microquasars should interact with the jet. This interaction, coupled with orbital motion, is expected to make the jet follow a helical, nonballistic trajectory. ...The jet energy dissipated by this interaction, through shocks for example, could lead to nonthermal activity on scales significantly larger than the system size. Aims. We calculate the broadband emission from a jet affected by the impact of the stellar wind and orbital motion in a high-mass microquasar. Methods. We employ a prescription for the helical trajectory of a jet in a system with a circular orbit. Subsequently, assuming electron acceleration at the onset of the helical jet region, we compute the spatial and energy distribution of these electrons, and their synchrotron and inverse Compton emission including gamma-ray absorption effects. Results. For typical source parameters, significant radio, X- and gamma-ray luminosities are predicted. The scales on which the emission is produced may reduce, but not erase, orbital variability of the inverse Compton emission. The wind and orbital effects on the radio emission morphology could be studied using very long baseline interferometric techniques. Conclusions. We predict significant broadband emission, modulated by orbital motion, from a helical jet in a high-mass microquasar. This emission may be hard to disentangle from radiation of the binary itself, although the light curve features, extended radio emission, and a moderate opacity to very high-energy gamma rays, could help to identify the contribution from an extended (helical) jet region.
BACKGROUND AND PURPOSE The endogenous cannabinoid system participates in oligodendrocyte progenitor differentiation in vitro. To determine the effect of synthetic cannabinoids on oligodendrocyte ...differentiation, we exposed differentiating cultures of oligodendrocytes with cannabinoid CB1, CB2 and CB1/CB2 receptor agonists and antagonists. The response of the PI3K/Akt and the mammalian target of rapamycin (mTOR) signalling pathways were studied as effectors of cannabinoid activity.
EXPERIMENTAL APPROACH Purified oligodendrocyte progenitor cells (OPC) obtained from primary mixed glial cell cultures were treated for 48 h with CB1, CB2 and CB1/CB2 receptor agonists (ACEA, JWH133 and HU210, respectively) in the presence or absence of the antagonists AM281 (CB1 receptor) and AM630 (CB2 receptor). Moreover, inhibitors of the phosphatidylinositol 3‐kinase (PI3K)/Akt and mTOR pathways (LY294002 and rapamycin, respectively) were used to study the involvement of these pathways on cannabinoid‐induced OPC maturation.
KEY RESULTS ACEA, JWH133 and HU‐210 enhanced OPC differentiation as assessed by the expression of stage specific antigens and myelin basic protein (MBP). Moreover, this effect was blocked by the CB receptor antagonists. ACEA, JWH133 and HU210 induced a time‐dependent phosphorylation of Akt and mTOR, whereas the inhibitors of PI3K/Akt (LY294002) or of mTOR (rapamycin) reversed the effects of HU‐210 on oligodendrocyte differentiation and kinase activation.
CONCLUSIONS AND IMPLICATIONS Activation of cannabinoid CB1 or CB2 receptors with selective agonists accelerated oligodendrocyte differentiation through the mTOR and Akt signalling pathways.
LINKED ARTICLES This article is part of a themed issue on Cannabinoids in Biology and Medicine. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2011.163.issue‐7
PDF
