114 research outputs found
Proteasome function is required for activation of programmed cell death in heat shocked tobacco Bright-Yellow 2 cells
AbstractTo find out whether and how proteasome is involved in plant programmed cell death (PCD) we measured proteasome function in tobacco cells undergoing PCD as a result of heat shock (HS-PCD). Reactive oxygen species (ROS) production, cytochrome c levels and caspase-3-like protease activation were also measured in the absence or presence of MG132, a proteasome inhibitor. We show that proteasome activation occurs in early phase of HS-PCD upstream of the caspase-like proteases activation; moreover inhibition of proteasome function by MG132 results in prevention of PCD perhaps due to the prevention of ROS production, cytochrome c release and caspase-3-like protease activation
Direct RNA Nanopore Sequencing of SARS-CoV-2 Extracted from Critical Material from Swabs
In consideration of the increasing prevalence of COVID-19 cases in several countries and the resulting demand for unbiased sequencing approaches, we performed a direct RNA sequencing (direct RNA seq.) experiment using critical oropharyngeal swab samples collected from Italian pa-tients infected with SARS-CoV-2 from the Palermo region in Sicily. Here, we identified the sequences SARS-CoV-2 directly in RNA extracted from critical samples using the Oxford Nanopore MinION technology without prior cDNA retrotranscription. Using an appropriate bioinformatics pipeline, we could identify mutations in the nucleocapsid (N) gene, which have been reported previously in studies conducted in other countries. In conclusion, to the best of our knowledge, the technique used in this study has not been used for SARS-CoV-2 detection previously owing to the difficulties in the extraction of RNA of sufficient quantity and quality from routine oropharyngeal swabs. Despite these limitations, this approach provides the advantages of true native RNA sequencing and does not include amplification steps that could introduce systematic errors. This study can provide novel information relevant to the current strategies adopted in SARS-CoV-2 next-generation sequencing
The Wolf-Rayet population of the nearby barred spiral galaxy NGC 5068 uncovered by the Very Large Telescope and Gemini
We present a narrow-band Very Large Telescope/Focal Reduced Low-dispersion Spectrograph #1 imaging survey of the SAB(rs)cd spiral galaxy NGCâ5068, located at a distance of 5.45âMpc, from which 160 candidate WolfâRayet sources have been identified, of which 59 cases possess statistically significant λ4686 excesses. Follow-up Gemini Multi-Object Spectrograph spectroscopy of 64 candidates, representing 40 per cent of the complete photometric catalogue, confirms WolfâRayet signatures in 30 instances, corresponding to a 47 per cent success rate. 21 out of 22 statistically significant photometric sources are spectroscopically confirmed. Nebular emission detected in 30 per cent of the WolfâRayet candidates spectrally observed, which enable a re-assessment of the metallicity gradient in NGCâ5068. A central metallicity of logâ(O/H) + 12 ⌠8.74 is obtained, declining to 8.23 at R25. We combine our spectroscopy with archival Hα images of NGCâ5068 to estimate a current star formation rate of Graphic, and provide a catalogue of the 28 brightest Hâii regions from our own continuum subtracted Hα images, of which âŒ17 qualify as giant Hâii regions. Spectroscopically, we identify 24 WC- and 18 WN-type WolfâRayet stars within 30 sources since emission-line fluxes indicate multiple WolfâRayet stars in several cases. We estimate an additional âŒ66 WolfâRayet stars from the remaining photometric candidates, although sensitivity limits will lead to an incomplete census of visually faint WN stars, from which we estimate a global population of âŒ170 WolfâRayet stars. Based on the Hα-derived O star population of NGCâ5068 and N(WR)/N(O) ⌠0.03, representative of the Large Magellanic Cloud, we would expect a larger WolfâRayet population of 270 stars. Finally, we have compared the spatial distribution of spectroscopically confirmed WN and WC stars with Sloan Digital Sky Survey derived supernovae, and find both WN and WC stars to be most consistent with the parent population of Type Ib supernovae
An exceptional population of late-type WC stars in the metal-rich spiral galaxy
We have surveyed the metal-rich spiral galaxy M83 (NGC5236) for its
Wolf-Rayet population using VLT-FORS2 narrow-band imaging and follow-up
spectroscopy. From a total of 280 candidates identified using HeII 4686
imaging, Multi Object Spectroscopy of 198 sources was carried out, revealing
132 objects containing bona-fide Wolf-Rayet features. From this sample, an
exceptional W-R content of 1030 is inferred, with N(WC)/N(WN)=1.3, continuing
the trend to larger values at higher metallicity amongst Local Group galaxies.
More dramatic is the dominance of late-type WC stars in M83 with
N(WC8-9)/N(WC4-7)=9 which we attribute to the sensitivity of the classification
line CIII 5696 to mass-loss, providing the strength of WC winds scale with
metallicity. One young massive compact cluster, #74 in our catalogue, hosts 20%
of the entire galactic population, namely 180 late WC stars and 50 late WN
stars.Comment: 4 pages, 2 figures, revised manuscript, accepted by A&A Letter
A mid-infrared spectroscopic survey of starburst galaxies: excitation and abundances
We present spectroscopy of MIR emission lines in twelve starburst regions,
located in eleven starburst galaxies, for which a significant number of lines
between 2.38 and 45micron were observed with the ISO Short Wavelength
Spectrometer, with the intention of providing a reference resource for MIR
spectra of starburst galaxies. The observation apertures were centred on
actively star forming regions, including those which are inaccessible at
optical wavelengths due to high levels of obscuration. We use this data set,
which includes fine structure and hydrogen recombination lines, to investigate
excitation and to derive gas phase abundances of neon, argon, and sulphur of
the starburst galaxies. The derived Ne abundances span approximately an order
of magnitude, up to values of ~3 times solar. The excitation ratios measured
from the Ne and Ar lines correlate well with each other (positively) and with
abundances (negatively). Both in excitation and abundance, a separation of
objects with visible Wolf-Rayet features (high excitation, low abundance) is
noted from those without (low excitation, high abundance). For a given
abundance, the starbursts are of relatively lower excitation than a comparative
sample of HII regions, possibly due to ageing stellar populations. By
considering the abundance ratios of S with Ne and Ar we find that, in our
higher metallicity systems, S is relatively underabundant by a factor of ~3. We
discuss the origin of this deficit and favour depletion of S onto dust grains
as a likely explanation. This weakness of the MIR fine structure lines of S has
ramifications for future infrared missions such as SIRTF and Herschel since it
indicates that the S lines are less favourable tracers of star formation than
is suggested by nebular models which do not consider this effect.Comment: 20 pages, 23 figures, Accepted for publication in A&
Reduction of serum IGF-I levels in patients affected with Monoclonal Gammopathies of undetermined significance or Multiple Myeloma. Comparison with bFGF, VEGF and K-ras gene mutation
<p>Abstract</p> <p>Background</p> <p>Serum levels of IGF-I in patients affected with multiple myeloma (MM) have been scarcely studied. The present study is aimed to explore this point comparing 55 healthy subjects, 71 monoclonal gammopaties of uncertain significance (MGUS) and 77 overt MM patients. In the same subjects, basic FGF and VEGF, have been detected. All three mediators were analyzed in function of K-<it>ras </it>mutation and melphalan response. Concerning IGF-I, two representative monitoring examples have also been added.</p> <p>Methods</p> <p>Cytokine determinations were performed by commercially available ELISA kits, while K12-<it>ras </it>mutation was investigated on genomic DNA isolated from bone marrow cell specimens by RFLP-PCR assay.</p> <p>Results</p> <p>Significant reductions of IGF-I levels were observed in MGUS and MM as compared with healthy controls. In addition, MM subjects showed significantly decreased serum IGF-I levels than MGUS. Conversely, increasing levels were observed for bFGF and VEGF, molecules significantly correlated. A multivariate analysis corrected for age and gender confirmed the significant difference only for IGF-I values (P = 0.01). K12-<it>ras </it>mutation was significantly associated with malignancy, response to therapy and with significantly increased serum bFGF levels.</p> <p>Conclusion</p> <p>IGF-I reduction in the transition: ControlsâMGUSâMM and changes observed over time suggest that IGF-I should be furtherly studied in future clinical trials as a possible monitoring marker for MM.</p
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transientâs position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Type Ibn Supernovae Show Photometric Homogeneity and Spectral Diversity at Maximum Light
Progressive skin fibrosis is associated with a decline in lung function and worse survival in patients with diffuse cutaneous systemic sclerosis in the European Scleroderma Trials and Research (EUSTAR) cohort.
Objectives To determine whether progressive skin fibrosis is associated with visceral organ progression and mortality during follow-up in patients with diffuse cutaneous systemic sclerosis (dcSSc). Methods We evaluated patients from the European Scleroderma Trials and Research database with dcSSc, baseline modified Rodnan skin score (mRSS) â„7, valid mRSS at 12±3 months after baseline and â„1 annual follow-up visit. Progressive skin fibrosis was defined as an increase in mRSS >5 and â„25% from baseline to 12±3 months. Outcomes were pulmonary, cardiovascular and renal progression, and all-cause death. Associations between skin progression and outcomes were evaluated by Kaplan-Meier survival analysis and multivariable Cox regression. Results Of 1021 included patients, 78 (7.6%) had progressive skin fibrosis (skin progressors). Median follow-up was 3.4 years. Survival analyses indicated that skin progressors had a significantly higher probability of FVC decline â„10% (53.6% vs 34.4%; p<0.001) and all-cause death (15.4% vs 7.3%; p=0.003) than non-progressors. These significant associations were also found in subgroup analyses of patients with either low baseline mRSS (â€22/51) or short disease duration (â€15 months). In multivariable analyses, skin progression within 1 year was independently associated with FVC decline â„10% (HR 1.79, 95% CI 1.20 to 2.65) and all-cause death (HR 2.58, 95% CI 1.31 to 5.09). Conclusions Progressive skin fibrosis within 1 year is associated with decline in lung function and worse survival in dcSSc during follow-up. These results confirm mRSS as a surrogate marker in dcSSc, which will be helpful for cohort enrichment in future trials and risk stratification in clinical practice
The International Natural Product Sciences Taskforce (INPST) and the power of Twitter networking exemplified through #INPST hashtag analysis
Background: The development of digital technologies and the evolution of open innovation approaches have enabled the creation of diverse virtual organizations and enterprises coordinating their activities primarily online. The open innovation platform titled "International Natural Product Sciences Taskforce" (INPST) was established in 2018, to bring together in collaborative environment individuals and organizations interested in natural product scientific research, and to empower their interactions by using digital communication tools. Methods: In this work, we present a general overview of INPST activities and showcase the specific use of Twitter as a powerful networking tool that was used to host a one-week "2021 INPST Twitter Networking Event" (spanning from 31st May 2021 to 6th June 2021) based on the application of the Twitter hashtag #INPST. Results and Conclusion: The use of this hashtag during the networking event period was analyzed with Symplur Signals (https://www.symplur.com/), revealing a total of 6,036 tweets, shared by 686 users, which generated a total of 65,004,773 impressions (views of the respective tweets). This networking event's achieved high visibility and participation rate showcases a convincing example of how this social media platform can be used as a highly effective tool to host virtual Twitter-based international biomedical research events
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