Introduction
This narrative review focusing on critical care echocardiography (CCE) has been written by a group of experts in the field, with the aim of outlining the state of the art in CCE in the ...10 years after its official recognition and definition.
Results
In the last 10 years, CCE has become an essential branch of critical care ultrasonography and has gained general acceptance. Its use, both as a diagnostic tool and for hemodynamic monitoring, has increased markedly, influencing contemporary cardiorespiratory management. Recent studies suggest that the use of CCE may have a positive impact on outcomes. CCE may be used in critically ill patients in many different clinical situations, both in their early evaluation of in the emergency department and during intensive care unit (ICU) admission and stay. CCE has also proven its utility in perioperative settings, as well as in the management of mechanical circulatory support. CCE may be performed with very simple diagnostic objectives. This application, referred to as basic CCE, does not require a high level of training. Advanced CCE, on the other hand, uses ultrasonography for full evaluation of cardiac function and hemodynamics, and requires extensive training, with formal certification now available. Indeed, recent years have seen the creation of worldwide certification in advanced CCE. While transthoracic CCE remains the most commonly used method, the transesophageal route has gained importance, particularly for intubated and ventilated patients.
Conclusion
CCE is now widely accepted by the critical care community as a valuable tool in the ICU and emergency department, and in perioperative settings.
We present the discovery of four new transiting hot Jupiters, detected mainly from SuperWASP-North and SOPHIE observations. These new planets, WASP-52b, WASP-58b, WASP-59b, and WASP-60b, have orbital ...periods ranging from 1.7 to 7.9 days, masses between 0.46 and 0.94 MJup, and radii between 0.73 and 1.49 RJup. Their G1 to K5 dwarf host stars have V magnitudes in the range 11.7−13.0. The depths of the transits are between 0.6 and 2.7%, depending on the target. With their large radii, WASP-52b and WASP-58b are new cases of low-density, inflated planets, whereas WASP-59b is likely to have a large, dense core. WASP-60 shows shallow transits. In the case of WASP-52 we also detected the Rossiter-McLaughlin anomaly via time-resolved spectroscopy of a transit. We measured the sky-projected obliquity λ = 24° +17-9, indicating that WASP-52b orbits in the same direction as its host star isrotating and that this prograde orbit is slightly misaligned with the stellar equator. These four new planetary systems increase our statistics on hot Jupiters and provide new targets for follow-up studies.
The ability of bone for regeneration has long been recognized. However, once beyond a critical size, spontaneous regeneration of bone is limited. Several studies have focused on enhancing bone ...regeneration by applying mesenchymal stromal/stem cells (MSCs) in the treatment strategies. Despite the therapeutic efficacy of MSCs in bone regeneration, cell-based therapies are impeded by several challenges in maintaining the optimal cell potency and viability during expansion, storage, and final delivery to patients. Recently, there has been a paradigm shift in therapeutic mechanism of MSCs in tissue repair from one based on cellular differentiation and replacement to one based on secretion and paracrine signaling. Among the broad spectrum of trophic factors, extracellular vesicles particularly the exosomes have been reported to be therapeutically efficacious in several injury/disease indications, including bone defects and diseases. The current systematic review aims to summarize the results of the existing animal studies which were conducted to evaluate the therapeutic efficacy of MSC exosomes for bone regeneration. Following the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines, the PubMed and The Cochrane Library database were searched for relevant controlled preclinical animal studies. A total of 23 studies were identified, with the total sample size being 690 rats or mice and 38 rabbits. Generally, MSC exosomes were found to be efficacious for bone regeneration in animal models of bone defects and diseases such as osteonecrosis and osteoporosis. In these studies, MSC exosomes promoted new bone formation with supporting vasculature and displayed improved morphological, biomechanical, and histological outcomes, coupled with positive effects on cell survival, proliferation, and migration, osteogenesis, and angiogenesis. Unclear-to-low risk in bias and incomplete reporting in the primary studies highlighted the need for standardization in outcome measurements and reporting. Further studies in large animal models to establish the safety and efficacy would provide useful information on guiding the design of clinical trials.
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•Therapeutic efficacy of MSC exosomes in bone regeneration was studied in 23 studies.•MSC exosomes are therapeutically efficacious in bone regeneration.•MSC exosomes improve morphological, biomechanical, and histological outcomes.•MSC exosomes promote a multifaceted mechanism in bone regeneration.
ABSTRACT
We present a study of photometric flares on 154 low-mass (≤0.2 M⊙) objects observed by the SPECULOOS-South Observatory from 2018 June 1 to 2020 March 23. In this sample, we identify 85 ...flaring objects, ranging in spectral type from M4 to L0. We detect 234 flares in this sample, with energies between 1029.2 and 1032.7 erg, using both automated and manual methods. With this work, we present the largest photometric sample of flares on late-M and ultra-cool dwarfs to date. By extending previous M dwarf flare studies into the ultra-cool regime, we find M5–M7 stars are more likely to flare than both earlier, and later, M dwarfs. By performing artificial flare injection-recovery tests, we demonstrate that we can detect a significant proportion of flares down to an amplitude of 1 per cent, and we are most sensitive to flares on the coolest stars. Our results reveal an absence of high-energy flares on the reddest dwarfs. To probe the relations between rotation and activity for fully convective stars, we extract rotation periods for fast rotators and lower-bound period estimates of slow rotators. These rotation periods span from 2.2 h to 65 d, and we find that the proportion of flaring stars increases for the most fastest rotators. Finally, we discuss the impact of our flare sample on planets orbiting ultra-cool stars. As stars become cooler, they flare less frequently; therefore, it is unlikely that planets around the most reddest dwarfs would enter the ‘abiogenesis’ zone or drive visible-light photosynthesis through flares alone.
We report the first detailed chemical abundance analysis of the exoplanet-hosting M-dwarf stars Kepler-138 and Kepler-186 from the analysis of high-resolution (R ∼ 22,500) H-band spectra from the ...SDSS-IV-APOGEE survey. Chemical abundances of 13 elements-C, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, and Fe-are extracted from the APOGEE spectra of these early M-dwarfs via spectrum syntheses computed with an improved line list that takes into account H2O and FeH lines. This paper demonstrates that APOGEE spectra can be analyzed to determine detailed chemical compositions of M-dwarfs. Both exoplanet-hosting M-dwarfs display modest sub-solar metallicities: Fe/HKepler-138 = −0.09 0.09 dex and Fe/HKepler-186 = −0.08 0.10 dex. The measured metallicities resulting from this high-resolution analysis are found to be higher by ∼0.1-0.2 dex than previous estimates from lower-resolution spectra. The C/O ratios obtained for the two planet-hosting stars are near-solar, with values of 0.55 0.10 for Kepler-138 and 0.52 0.12 for Kepler-186. Kepler-186 exhibits a marginally enhanced Si/Fe ratio.
We report the discovery and characterisation of a super-Earth and a sub-Neptune transiting the bright (
K
= 8.8), quiet, and nearby (37 pc) M3V dwarf TOI-1266. We validate the planetary nature of ...TOI-1266 b and c using four sectors of TESS photometry and data from the newly-commissioned 1-m SAINT-EX telescope located in San Pedro Mártir (México). We also include additional ground-based follow-up photometry as well as high-resolution spectroscopy and high-angular imaging observations. The inner, larger planet has a radius of
R
= 2.37
−0.12
+0.16
R
⊕
and an orbital period of 10.9 days. The outer, smaller planet has a radius of
R
= 1.56
−0.13
+0.15
R
⊕
on an 18.8-day orbit. The data are found to be consistent with circular, co-planar and stable orbits that are weakly influenced by the 2:1 mean motion resonance. Our TTV analysis of the combined dataset enables model-independent constraints on the masses and eccentricities of the planets. We find planetary masses of
M
p
= 13.5
−9.0
+11.0
M
⊕
(<36.8
M
⊕
at 2-
σ
) for TOI-1266 b and 2.2
−1.5
+2.0
M
⊕
(<5.7
M
⊕
at 2-
σ
) for TOI-1266 c. We find small but non-zero orbital eccentricities of 0.09
−0.05
+0.06
(<0.21 at 2-
σ
) for TOI-1266 b and 0.04 ± 0.03 (< 0.10 at 2-
σ
) for TOI-1266 c. The equilibrium temperatures of both planets are of 413 ± 20 and 344 ± 16 K, respectively, assuming a null Bond albedo and uniform heat redistribution from the day-side to the night-side hemisphere. The host brightness and negligible activity combined with the planetary system architecture and favourable planet-to-star radii ratios makes TOI-1266 an exquisite system for a detailed characterisation.
To establish a process to evaluate and standardize a state-of-the-art nomenclature for reporting neovascular age-related macular degeneration (AMD) data.
Consensus meeting.
An international panel of ...retina specialists, imaging and image reading center experts, and ocular pathologists.
During several meetings organized under the auspices of the Macula Society, an international study group discussed and codified a set nomenclature framework for classifying the subtypes of neovascular AMD and associated lesion components.
A consensus classification of neovascular AMD.
The study group created a standardized working definition of AMD. The components of neovascular AMD were defined and subclassified. Disease consequences of macular neovascularization were delineated.
The framework of a consensus nomenclature system, a definition of AMD, and a delineation of the subtypes of neovascular AMD were developed. Establishing a uniform set of definitions will facilitate comparison of diverse patient groups and different studies. The framework presented is modified and updated readily, processes that are anticipated to occur on a periodic basis. The study group suggests that the consensus standards outlined in this article be used in future reported studies of neovascular AMD and clinical practice.
After CNS injury, axon regeneration is blocked by an inhibitory environment consisting of the highly upregulated tenascin-C and chondroitin sulfate proteoglycans (CSPGs). Tenascin-C promotes growth ...of axons if they express a tenascin-binding integrin, particularly α9β1. Additionally, integrins can be inactivated by CSPGs, and this inhibition can be overcome by the presence of a β1-binding integrin activator, kindlin-1. We examined the synergistic effect of α9 integrin and kindlin-1 on sensory axon regeneration in adult rat spinal cord after dorsal root crush and adeno-associated virus transgene expression in dorsal root ganglia. After 12 weeks, axons from C6-C7 dorsal root ganglia regenerated through the tenascin-C-rich dorsal root entry zone into the dorsal column up to C1 level and above (>25 mm axon length) through a normal pathway. Animals also showed anatomical and electrophysiological evidence of reconnection to the dorsal horn and behavioral recovery in mechanical pressure, thermal pain, and ladder-walking tasks. Expression of α9 integrin or kindlin-1 alone promoted much less regeneration and recovery.
The study demonstrates that long-distance sensory axon regeneration over a normal pathway and with sensory and sensory-motor recovery can be achieved. This was achieved by expressing an integrin that recognizes tenascin-C, one of the components of glial scar tissue, and an integrin activator. This enabled extensive long-distance (>25 mm) regeneration of both myelinated and unmyelinated sensory axons with topographically correct connections in the spinal cord. The extent of growth and recovery we have seen would probably be clinically significant. Restoration of sensation to hands, perineum, and genitalia would be a significant improvement for a spinal cord-injured patient.
The identification of metal ions and particles in the vicinity of failed implants has raised the concern that biomedical titanium alloys undergo corrosion in healthy and infected tissues. Various ...surface modifications and coatings have been investigated to prevent the deterioration and biocorrosion of titanium alloys but so far with limited success. Graphene is a cytocompatible atom-thick film made of carbon atoms. It has a very high surface area and can be deposited onto metal objects with complex shapes. As the carbon lattice has a very small pore size, graphene has promising impermeability capacity. Here, we show that graphene coating can effectively protect Ti-6Al-4V from corrosion. Graphene nanocoatings were produced on Ti-6Al-4V grade 5 and 23 discs and subjected to corrosive challenge (0.5M NaCl supplemented with 2-ppm fluoride, pH of 2.0) up to 30 d. The linear polarization resistance curves and electrochemical impedance spectroscopy analysis showed that the graphene-coated samples presented higher corrosion resistance and electrochemical stability at all time points. Moreover, the corrosion rate of the graphene-coated samples was very low and stable (~0.001 mm/y), whereas that of the uncoated controls increased up to 16 and 5 times for grade 5 and 23 (~0.091 mm/y) at the end point, respectively. The surface oxidation, degradation (e.g., crevice defects), and leaching of Ti, Al, and V ions observed in the uncoated controls were prevented by the graphene nanocoating. The Raman mappings confirmed that the graphene nanocoating presented high structural stability and resistance to mechanical stresses and chemical degradation, keeping >99% of coverage after corrosion challenge. Our findings open the avenues for the use of graphene as anticorrosion coatings for metal biomedical alloys and implantable devices.
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