5,193 research outputs found
Why should we switch chest compression providers every 2 minutes during cardiopulmonary resuscitation?
Objective. Tis study was conducted to determine whether trained male rescuers could maintain adequate chest compression depth (CCD) for longer than the current recommended guidelines of 2 minutes.
Methods. Forty male medical doctors administered a 5-minute single rescuer cardiopulmonary resuscitation (CPR) to a manikin on the foor with conventional CPR or randomly administered continuous chest compressions (CCC). Te ratio of compression to ventilation was set to
30:2 with mouth-to-mouth technique during conventional CPR. Chest compression data were recorded with an accelerometer
device and divided into 1-minute segments for analysis.
Results. Although average CCD maintained the recommended depths throughout 5 minutes in conventional CPR, it decreased signifcantly with CCC (1 minute: 55.4 ± 4.5 mm; 2 minutes: 54.2 ± 5.4 mm;
3 minutes: 52.6 ± 5.6 mm; 4 minutes: 51.6 ± 5.5 mm; 5 minutes: 49.9 ± 5.8 mm, p < 0.001). Te average chest compression
numbers (ACCN) per minute were maintained over 80/min and have not been changed signifcantly within 5 minutes in the CCC. However, it didnât reach to the 80/min and decreased signifcantly afer 3minutes compared to the baseline ACCN during frst 1-minute segment in the conventional CPR. Conclusions. Despite the chest compression providers being limited to trained male medical doctors, the average CCD
decreased signifcantly within 5minutes with CCC. Although maintaining adequate CCD, ACCN in each minute decreased signifcantly afer 3minutes in the conventional CPR. Terefore, we should rotate chest
compression providers every 2minutes regardless of the rescuerâs qualifcations and
CPR methods
Quaternary semiconductor Cu2FeSnS4 nanoparticles as an alternative to Pt catalysts
We demonstrate an N719 dye sensitized solar cell based on Cu 2FeSnS4 (CFTS) as a counter electrode. The elements for the material are all earth abundant and environmentally benign. The power conversion efficiency of a DSSC using CFTS was comparable to that of a DSSC using Pt under A.M. 1.5G (100 mW cm-2).close3
Adjunctive biomarkers for improving diagnosis of tuberculosis and monitoring therapeutic effects
SummaryObjectivesTo identify host biomarkers associated with latent tuberculosis infection (LTBI), active tuberculosis (TB), and nontuberculous mycobacteria (NTM) diseases to improve diagnosis and effective anti-TB treatment.MethodsActive TB and NTM patients at diagnosis, recent TB contacts, and normal healthy subjects were recruited. Tuberculin skin tests, QuantiFERON-TB Gold In-Tube tests, and multiplex bead arrays with 17 analytes were performed. TB patients were re-evaluated after 2 and 6 months of treatment.ResultsMycobacterium tuberculosis (M. tb) antigen-specific IFN-γ, IL-2, and CXCL10 responses were significantly higher in active TB and LTBI compared with controls (P < 0.01). Only serum VEGF levels varied between the active TB and LTBI groups (AUC = 0.7576, P < 0.001). Active TB and NTM diseases were differentiated by serum IL-2, IL-9, IL-13, IL-17, TNF-α and sCD40L levels (P < 0.05). Increased sCD40L and decreased M. tb antigen-specific IFN-γ levels correlated with sputum clearance of M. tb after 2 months of treatment (P < 0.001).ConclusionsSerum IL-2, IL-9, IL-13, IL-17, TNF-α, sCD40L and VEGF-A levels may be adjunctive biomarkers for differential diagnosis of active TB, LTBI, and NTM disease. Assessment of serum sCD40L and M. tb antigen-specific IFN-γ, TNF-α, and IL-2 levels could help predict successful anti-TB treatment in conjunction with M. tb clearance
Inhibitory effect of a tyrosine-fructose Maillard reaction product, 2,4-bis(p-hydroxyphenyl)-2-butenal on amyloid-ÎČ generation and inflammatory reactions via inhibition of NF-ÎșB and STAT3 activation in cultured astrocytes and microglial BV-2 cells
<p>Abstract</p> <p>Background</p> <p>Amyloidogenesis is linked to neuroinflammation. The tyrosine-fructose Maillard reaction product, 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal, possesses anti-inflammatory properties in cultured macrophages, and in an arthritis animal model. Because astrocytes and microglia are responsible for amyloidogenesis and inflammatory reactions in the brain, we investigated the anti-inflammatory and anti-amyloidogenic effects of 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal in lipopolysaccharide (LPS)-stimulated astrocytes and microglial BV-2 cells.</p> <p>Methods</p> <p>Cultured astrocytes and microglial BV-2 cells were treated with LPS (1 ÎŒg/ml) for 24 h, in the presence (1, 2, 5 ÎŒM) or absence of 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal, and harvested. We performed molecular biological analyses to determine the levels of inflammatory and amyloid-related proteins and molecules, cytokines, AÎČ, and secretases activity. Nuclear factor-kappa B (NF-ÎșB) DNA binding activity was determined using gel mobility shift assays.</p> <p>Results</p> <p>We found that 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal (1, 2, 5 ÎŒM) suppresses the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) as well as the production of nitric oxide (NO), reactive oxygen species (ROS), tumor necrosis factor-α (TNF-α), and interleukin-1ÎČ (IL-1ÎČ) in LPS (1 ÎŒg/ml)-stimulated astrocytes and microglial BV-2 cells. Further, 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal inhibited the transcriptional and DNA binding activity of NF-ÎșB--a transcription factor that regulates genes involved in neuroinflammation and amyloidogenesis via inhibition of IÎșB degradation as well as nuclear translocation of p50 and p65. Consistent with the inhibitory effect on inflammatory reactions, 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal inhibited LPS-elevated AÎČ<sub>42 </sub>levels through attenuation of ÎČ- and Îł-secretase activities. Moreover, studies using signal transducer and activator of transcription 3 (STAT3) siRNA and a pharmacological inhibitor showed that 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal inhibits LPS-induced activation of STAT3.</p> <p>Conclusions</p> <p>These results indicate that 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal inhibits neuroinflammatory reactions and amyloidogenesis through inhibition of NF-ÎșB and STAT3 activation, and suggest that 2,4-bis(<it>p</it>-hydroxyphenyl)-2-butenal may be useful for the treatment of neuroinflammatory diseases like Alzheimer's disease.</p
The Globular Cluster System of M60 (NGC 4649). I. CFHT MOS Spectroscopy and Database
We present the measurement of radial velocities for globular clusters in M60,
giant elliptical galaxy in the Virgo cluster. Target globular cluster
candidates were selected using the Washington photometry based on the deep
16\arcmin \times 16\arcmin images taken at the KPNO 4m and using the
photometry derived from the HST/WFPC2 archive images. The spectra of the target
objects were obtained using the Multi-Object Spectrograph (MOS) at the
Canada-France-Hawaii Telescope (CFHT). We have measured the radial velocity for
111 objects in the field of M60: 93 globular clusters (72 blue globular
clusters with and 21 red globular clusters with
), 11 foreground stars, 6 small galaxies, and the nucleus of
M60. The measured velocities of the 93 globular clusters range from
km s to km s, with a mean value of
km s, which is in good agreement with the velocity of the nucleus of M60
( km s). Combining our results with data in the
literature, we present a master catalog of radial velocities for 121 globular
clusters in M60. The velocity dispersion of the globular clusters in the master
catalog is found to be km s for the entire sample,
km s for 83 blue globular clusters, and
km s for 38 red globular clusters.Comment: 29 pages, 8 figures. To appear in Ap
Chemical homogeneity of wide binary system: An approach from Near-Infrared spectroscopy
Wide binaries, with separations between two stars from a few AU to more than
several thousand AU, are valuable objects for various research topics in
Galactic astronomy. As the number of newly reported wide binaries continues to
increase, studying the chemical abundances of their component stars becomes
more important. We conducted high-resolution near-infrared (NIR) spectroscopy
for six pairs of wide binary candidates using the Immersion Grating Infrared
Spectrometer (IGRINS) at the Gemini-South telescope. One pair was excluded from
the wide binary samples due to a significant difference in radial velocity
between its component stars, while the remaining five pairs exhibited
homogeneous properties in 3D motion and chemical composition among the pair
stars. The differences in [Fe/H] ranged from 0.00 to 0.07 dex for these wide
binary pairs. The abundance differences between components are comparable to
the previous results from optical spectroscopy for other samples. In addition,
when combining our data with literature data, it appears that the variation of
abundance differences increases in wide binaries with larger separations.
However, the SVO2324 and SVO3206 showed minimal differences in most elements
despite their large separation, supporting the concept of multiple formation
mechanisms depending on each wide binary. This study is the first approach to
the chemical properties of wide binaries based on NIR spectroscopy. Our results
further highlight that NIR spectroscopy is an effective tool for stellar
chemical studies based on equivalent measurements of chemical abundances from
the two stars in each wide binary system.Comment: 16 pages, 9 figures, accepted for publication in A
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