In a new model of peripheral localized inflammation, induced by intraplantar endotoxin (1.25 μg) injection in the hind paw of rats and mice, thymulin, a hormone of the thymus gland involved in ...immunomodulation, reduced inflammatory pain. High doses of thymulin reduced significantly, and in a dose-dependent manner, mechanical hyperalgesia as assessed by the paw pressure test and thermal hyperalgesia as assessed by the hot plate test and tail immersion test.
C-Fos-like immunoreactivity (FLI) in the central nervous system, has been associated with the processing of nociceptive information in acute and chronic pain animal models. The aim of this study was ...to investigate whether intraplantar (i.pl.) injections of endotoxin (ET, 1.25 μg) can induce FLI in the lumbar spinal cord of rats and to assess the effects of morphine injection on c-fos expression. FLI was studied in various groups of rats at 2, 3, 4, 6, 9 and 24 h following ET injections. Labeled neurons were mainly detected in the lumbar segments ipsilateral to the ET-injected leg, with a major peak (71.01±4.79 positive neurons) at 4 h and a second peak (29.87±5.97 positive neurons) at 9 h followed by a recovery to the baseline at 24 h after ET injections. Within the laminae, the majority of positive neurons was observed at 2–3 h in laminae I and II and in deep laminae (V and VI mainly) starting at 4 h after ET injections. Rostrocaudally, labeled neurons were observed initially in L
4–L
5 segments (2–3 h post-ET) after which they extended to L
2–L
6 segments at 4 h after ET. Morphine injections either i.p. (1 or 2 mg/kg) or i.pl. (50 μg) significantly reduced ET-induced hyperalgesia and simultaneously the FLI. The maximum effect was observed on labeled neurons in the deep laminae (V and VI mainly). We conclude that local injections of ET can induce FLI in the lumbar spinal cord with a temporal and spatial patterns comparable to the described hyperalgesia, and that both FLI and hyperalgesia are reduced by morphine in a dose-dependent manner with a maximal effect shown by the local i.pl. morphine injections.
Classical Be stars are hot non-supergiant stars surrounded by a gaseous circumstellar disk that is responsible for the observed infrared-excess and emission lines. The phenomena involved in the disk ...formation still remain highly debated. To progress in the understanding of the physical process or processes responsible for the mass ejections and test the hypothesis that they depend on the stellar parameters, the authors initiated a survey on the circumstellar environment of the brightest Be stars. To achieve this goal, they used spectro-interferometry, the only technique that combines high spectral and high spatial resolutions. Observations were carried out at the Paranal observatory with the VLTI/AMBER instrument. They managed to determine the disk extension in the line and the nearby continuum for most targets. They also constrained the disk kinematics, showing that it is dominated by rotation with a rotation law close to the Keplerian one.
Context. Classical Be stars are hot non-supergiant stars surrounded by a gaseous circumstellar disk that is responsible for the observed infrared-excess and emission lines. The phenomena involved in ...the disk formation still remain highly debated. Aims. To progress in the understanding of the physical process or processes responsible for the mass ejections and test the hypothesis that they depend on the stellar parameters, we initiated a survey on the circumstellar environment of the brightest Be stars. Methods. To achieve this goal, we used spectro-interferometry, the only technique that combines high spectral (R = 12 000) and high spatial (θmin = 4 mas) resolutions. Observations were carried out at the Paranal observatory with the VLTI/AMBER instrument. We concentrated our observations on the Brγ emission line to be able to study the kinematics within the circumstellar disk. Our sample is composed of eight bright classical Be stars: α Col, κ CMa, ω Car, p Car, δ Cen, μ Cen, α Ara, and o Aqr. Results. We managed to determine the disk extension in the line and the nearby continuum for most targets. We also constrained the disk kinematics, showing that it is dominated by rotation with a rotation law close to the Keplerian one. Our survey also suggests that these stars are rotating at a mean velocity of V/Vc = 0.82 ± 0.08. This corresponds to a rotational rate of Ω/Ωc = 0.95 ± 0.02. Conclusions. We did not detect any correlation between the stellar parameters and the structure of the circumstellar environment. Moreover, it seems that a simple model of a geometrically thin Keplerian disk can explain most of our spectrally resolved K-band data. Nevertheless, some small departures from this model have been detected for at least two objects (i.e., κ CMa and α Col). Finally, our Be stars sample suggests that rotation is the main physical process driving the mass-ejection. Nevertheless, smaller effects from other mechanisms have to be taken into account to fully explain how the residual gravity is compensated.
Context. To progress in the understanding of evolution of massive stars one needs to constrain the mass-loss and determine the phenomenon responsible for the ejection of matter an its reorganization ...in the circumstellar environment Aims. In order to test various mass-ejection processes, we probed the geometry and kinematics of the dust and gas surrounding the Ae supergiant HD 62623. Methods. We used the combined high spectral and spatial resolution offered by the VLTI/AMBER instrument. Thanks to a new multi-wavelength optical/IR interferometry imaging technique, we reconstructed the first velocity-resolved images with a milliarcsecond resolution in the infrared domain. Results. We managed to disentangle the dust and gas emission in the HD 62623 circumstellar disc. We measured the dusty disc inner rim, i.e. 6 mas, constrained the inclination angle and the position angle of the major-axis of the disc. We also measured the inner gaseous disc extension (2 mas) and probed its velocity field thanks to AMBER high spectral resolution. We find that the expansion velocity is negligible, and that Keplerian rotation is a favoured velocity field. Such a velocity field is unexpected if fast rotation of the central star alone is the main mechanism of matter ejection. Conclusions. As the star itself seems to rotate below its breakup-up velocity, rotation cannot explain the formation of the dense equatorial disc. Moreover, as the expansion velocity is negligible, radiatively driven wind is also not a suitable explanation to explain the disc formation. Consequently, the most probable hypothesis is that the accumulation of matter in the equatorial plane is due to the presence of the spectroscopic low mass companion.
The formation and evolution of gas and dust environments around Be supergiants are still open issues. In this paper, the authors intend to study the geometry, kinematics and physical structure of the ...circumstellar environment (CE) of the Be supergiant CPD-52 9243 to provide further insights into the underlying mechanism causing the Be phenomenon. High angular resolution interferometric measurements obtained with VLTI/MIDI provide strong support for the presence of a dusty disk-like structure around CPD-52 9243, with an upper limit for its inner edge of similar to 8 mas. The IR emission indicates Keplerian rotation in a circumstellar disk while the optical line transitions of various species are consistent with a polar wind. Both structures appear simultaneously and provide further evidence for the proposed paradigms of the mass-loss in supergiant Be stars. More spectroscopic and interferometric data are necessary to determine a possible binary nature of the star.
Many applications in nanotechnology require short and unentangled single-walled carbon nanotubes (SWCNT). Liquid-phase oxidative cutting gives nonuniform short tubes and causes significant material ...loss. Mechanical cutting is good for shortening SWCNT, but it leaves collapsed tube ends and might not be favorable for further manipulation. Solid-state reaction cutting is better for multi-walled carbon nanotubes than for SWCNT. Herein, we present a method combining mechanical and oxidative cutting. The SWCNT sample was first ground with a Wig-L-Bug grinding mill for 30min, introducing structural defects into the side walls of SWCNT. The treated SWCNT were then soaked in a Piranha solution, in which the oxidants attack the existing side wall defects and give a complete cut. According to statistical analysis from transmission electron microscopy, most of the shortened SWCNT fall in the range of 50–200nm. The material loss is 12.2wt%. The functional groups on the tube surface introduced by shortening were removed by refluxing in a soda lime/water suspension. Then, the carbon nanotubes were further annealed by sonicating in ethanol. After annealing, the defect level of shortened carbon nanotubes was reduced significantly, as determined by Raman spectroscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis.
We present a publicly available dataset of 227 healthy participants comprising a young (N=153, 25.1±3.1 years, range 20-35 years, 45 female) and an elderly group (N=74, 67.6±4.7 years, range 59-77 ...years, 37 female) acquired cross-sectionally in Leipzig, Germany, between 2013 and 2015 to study mind-body-emotion interactions. During a two-day assessment, participants completed MRI at 3 Tesla (resting-state fMRI, quantitative T1 (MP2RAGE), T2-weighted, FLAIR, SWI/QSM, DWI) and a 62-channel EEG experiment at rest. During task-free resting-state fMRI, cardiovascular measures (blood pressure, heart rate, pulse, respiration) were continuously acquired. Anthropometrics, blood samples, and urine drug tests were obtained. Psychiatric symptoms were identified with Standardized Clinical Interview for DSM IV (SCID-I), Hamilton Depression Scale, and Borderline Symptoms List. Psychological assessment comprised 6 cognitive tests as well as 21 questionnaires related to emotional behavior, personality traits and tendencies, eating behavior, and addictive behavior. We provide information on study design, methods, and details of the data. This dataset is part of the larger MPI Leipzig Mind-Brain-Body database.
Context. As is the case of several other Be stars, Achernar is surrounded by an envelope, recently detected by near-IR interferometry. Aims. We search for the signature of circumstellar emission at ...distances of a few stellar radii from Achernar, in the thermal IR domain. Methods. We obtained interferometric observations on three VLTI baselines in the N band (8-13 μm), using the MIDI instrument. Results. From the measured visibilities, we derive the angular extension and flux contribution of the N band circumstellar emission in the polar direction of Achernar. The interferometrically resolved polar envelope contributes 13.4 ± 2.5% of the photospheric flux in the N band, with a full width at half maximum of 9.9 ± 2.3 mas (≈$6~R_\star$). This flux contribution is in good agreement with the photometric IR excess of 10-20% measured by fitting the spectral energy distribution. Due to our limited azimuth coverage, we can only establish an upper limit of 5-10% for the equatorial envelope. We compare the observed properties of the envelope with an existing model of this star computed with the SIMECA code. Conclusions. The observed extended emission in the thermal IR along the polar direction of Achernar is well reproduced by the existing SIMECA model. Already detected at 2.2 μm, this polar envelope is most probably an observational signature of the fast wind ejected by the hot polar caps of the star.
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