41 research outputs found
Precursors of fatty alcohols in the ISM: Discovery of n-propanol
Theories on the origins of life propose that early cell membranes were
synthesized from amphiphilic molecules simpler than phospholipids such as fatty
alcohols. The discovery in the interstellar medium (ISM) of ethanolamine, the
simplest phospholipid head group, raises the question whether simple
amphiphilic molecules are also synthesized in space. We investigate whether
precursors of fatty alcohols are present in the ISM. For this, we have carried
out a spectral survey at 7, 3, 2 and 1 mm toward the Giant Molecular Cloud
G+0.693-0.027 located in the Galactic Center using the IRAM 30m and Yebes 40m
telescopes. Here, we report the detection in the ISM of the primary alcohol
n-propanol (in both conformers Ga-n-C3H7OH and Aa-n-C3H7OH), a precursor of
fatty alcohols. The derived column densities of n-propanol are (5.5+-0.4)x10^13
cm^-2 for the Ga conformer and (3.4+-0.3)x10^13 cm^-2 for the Aa conformer,
which imply molecular abundances of (4.1+-0.3)x10^-10 for Ga-n-C3H7OH and of
(2.5+-0.2)x10^-10 for Aa-n-C3H7OH. We also searched for the AGa conformer of
n-butanol (AGa-n-C4H9OH) without success yielding an upper limit to its
abundance of <4.1x10^-11. The inferred CH3OH:C2H5OH:C3H7OH:C4H9OH abundance
ratios go as 1:0.04:0.006:<0.0004 toward G+0.693-0.027, i.e. they decrease
roughly by one order of magnitude for increasing complexity. We also report the
detection of both syn and anti conformers of vinyl alcohol, with column
densities of (1.11+-0.08)x10^14 cm^-2 and (1.3+-0.4)x10^13 cm^-2, and
abundances of (8.2+-0.6)x10^-10 and (9.6+-3.0)x10^-11, respectively. The
detection of n-propanol, together with the recent discovery of ethanolamine in
the ISM, opens the possibility that precursors of lipids according to theories
of the origin of life, could have been brought to Earth from outer space.Comment: 15 pages, 10 figures, accepted for A&
Evaluating the extent and impact of the extreme Storm Gloria on Posidonia oceanica seagrass meadows
Extreme storms can trigger abrupt and often lasting changes in ecosystems by affecting foundational (habitat-forming) species. While the frequency and intensity of extreme events are projected to increase under climate change, its impacts on seagrass ecosystems remain poorly documented. In January 2020, the Spanish Mediterranean coast was hit by Storm Gloria, one of the most devastating recent climate events in terms of intensity and duration. We conducted rapid surveys of 42 Posidonia oceanica meadows across the region to evaluate the extent and type of impact (burial, unburial and uprooting). We investigated the significance of oceanographic (wave impact model), geomorphological (latitude, depth, exposure), and structural (patchiness) factors in predicting impact extent and intensity. The predominant impact of Storm Gloria was shoot unburial. More than half of the surveyed sites revealed recent unburial, with up to 40 cm of sediment removed, affecting over 50 % of the meadow. Burial, although less extensive, was still significant, with 10–80 % of meadow cover being buried under 7 cm of sediment, which is considered a survival threshold for P. oceanica. In addition, we observed evident signs of recently dead matte in some meadows and large amounts of detached drifting shoots on the sea bottom or accumulated as debris on the beaches. Crucially, exposed and patchy meadows were much more vulnerable to the overall impact than sheltered or continuous meadows. Given how slow P. oceanica is able to recover after disturbances, we state that it could take from decades to centuries for it to recoup its losses. Seagrass ecosystems play a vital role as coastal ecological infrastructure. Protecting vulnerable meadows from anthropogenic fragmentation is crucial for ensuring the resilience of these ecosystems in the face of the climate crisis.This study was funded by the CSIC project “Effects of storm Gloria on the western Mediterranean meadows (202030E052) and “Storms of change: as phenomena extreme weather alters Mediterranean coastal ecosystems, their services and their perception by society" (PID2020-113745RB-I00), state program of I+D+I Oriented to the Challenges of the Society and within the framework of the activities of the Spanish Government through the "Maria de Maeztu Centre of Excellence” accreditation to IMEDEA (CSIC-UIB) (CEX2021-001198). We want to thank the SPAS (Society of Fishing and Underwater Activities of Mataró) and the Mataró City Council, which has financed 25 years of the Alguer de Mataró project
Workflow times and outcomes in patients triaged for a suspected severe stroke
Introduction: Current recommendations for regional stroke destination suggest that patients with severe acute stroke in non-urban areas should be triaged based on the estimated transport time to a referral thrombectomy-capable center. Methods: We performed a post hoc analysis to evaluate the association of pre-hospital workflow times with neurological outcomes in patients included in the RACECAT trial. Workflow times evaluated were known or could be estimated before transport allocation. Primary outcome was the shift analysis on the modified Rankin score at 90 days. Results: Among the 1,369 patients included, the median time from onset to emergency medical service (EMS) evaluation, the estimated transport time to a thrombectomy-capable center and local stroke center, and the estimated transfer time between centers were 65 minutes (interquartile ratio [IQR] = 43–138), 61 minutes (IQR = 36–80), 17 minutes (IQR = 9–27), and 62 minutes (IQR = 36–73), respectively. Longer time intervals from stroke onset to EMS evaluation were associated with higher odds of disability at 90 days in the local stroke center group (adjusted common odds ratio (acOR) for each 30-minute increment = 1.03, 95% confidence interval [CI] = 1.01–1.06), with no association in the thrombectomy-capable center group (acOR for each 30-minute increment = 1.01, 95% CI = 0.98–1.01, pinteraction = 0.021). No significant interaction was found for other pre-hospital workflow times. In patients evaluated by EMS later than 120 minutes after stroke onset, direct transport to a thrombectomy-capable center was associated with better disability outcomes (acOR = 1.49, 95% CI = 1.03–2.17). Conclusion: We found a significant heterogeneity in the association between initial transport destination and neurological outcomes according to the elapse of time between the stroke onset and the EMS evaluation (ClinicalTrials.gov: NCT02795962). ANN NEUROL 2022;92:931–942
HTLV-1 infection in solid organ transplant donors and recipients in Spain
Background: HTLV-1 infection is a neglected disease, despite infecting 10–15 million people worldwide and
severe illnesses develop in 10% of carriers lifelong. Acknowledging a greater risk for developing HTLV-1
associated illnesses due to immunosuppression, screening is being widely considered in the transplantation
setting. Herein, we report the experience with universal HTLV testing of donors and recipients of solid organ
transplants in a survey conducted in Spain.
Methods: All hospitals belonging to the Spanish HTLV network were invited to participate in the study. Briefly, HTLV
antibody screening was performed retrospectively in all specimens collected from solid organ donors and recipients
attended since the year 2008.
Results: A total of 5751 individuals were tested for HTLV antibodies at 8 sites. Donors represented 2312
(42.2%), of whom 17 (0.3%) were living kidney donors. The remaining 3439 (59.8%) were recipients. Spaniards
represented nearly 80%.
Overall, 9 individuals (0.16%) were initially reactive for HTLV antibodies. Six were donors and 3 were recipients.
Using confirmatory tests, HTLV-1 could be confirmed in only two donors, one Spaniard and another from
Colombia. Both kidneys of the Spaniard were inadvertently transplanted. Subacute myelopathy developed
within 1 year in one recipient. The second recipient seroconverted for HTLV-1 but the kidney had to be
removed soon due to rejection. Immunosuppression was stopped and 3 years later the patient remains in
dialysis but otherwise asymptomatic.
Conclusion: The rate of HTLV-1 is low but not negligible in donors/recipients of solid organ transplants in
Spain. Universal HTLV screening should be recommended in all donor and recipients of solid organ
transplantation in Spain. Evidence is overwhelming for very high virus transmission and increased risk along
with the rapid development of subacute myelopath
Rapid subacute myelopathy following kidney transplantation from HTLV-1 donors: role of immunosuppresors and failure of antiretrovirals
Two kidney transplant recipients from a single donor became infected with HTLV-1 (human T-lymphotropic virus type 1) in Spain. One developed myelopathy 8 months following surgery despite early prescription of antiretroviral therapy. The allograft was removed from the second recipient at month 8 due to rejection and immunosuppressors discontinued. To date, 3 years later, this patient remains infected but asymptomatic. HTLV-1 infection was recognized retrospectively in the donor, a native Spaniard who had sex partners from endemic regions. Our findings call for a reappraisal of screening policies on donor-recipient organ transplantation. Based on the high risk of disease development and the large flux of persons from HTLV-1 endemic regions, pre-transplant HTLV-1 testing should be mandatory in Spain
Consensus guidelines for the use and interpretation of angiogenesis assays
The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference
Molecular Precursors of the RNA-World in Space: New Nitriles in the G+0.693-0.027 Molecular Cloud
Nitriles play a key role as molecular precursors in prebiotic experiments based on the RNA-world scenario for the origin of life. These chemical compounds could have been partially delivered to the young Earth from extraterrestrial objects, stressing the importance of establishing the reservoir of nitriles in the interstellar medium. We report here the detection towards the molecular cloud G+0.693-0.027 of several nitriles, including cyanic acid (HOCN), and three C4H3N isomers (cyanoallene, CH2CCHCN; propargyl cyanide, HCCCH2CN; and cyanopropyne (CH3CCCN), and the tentative detections of cyanoformaldehyde (HCOCN), and glycolonitrile (HOCH2CN). We have also performed the first interstellar search of cyanoacetaldehyde (HCOCH2CN), which was not detected. Based on the derived molecular abundances of the different nitriles in G+0.693-0.027 and other interstellar sources, we have discussed their formation mechanisms in the ISM. We propose that the observed HOCN abundance in G+0.693-0.027 is mainly due to surface chemistry and subsequent shock-induced desorption, while HCOCN might be mainly formed through gas-phase chemistry. In the case of HOCH2CN, several grain-surface routes from abundant precursors could produce it. The derived abundances of the three C4H3N isomers in G+0.693-0.027 are very similar, and also similar to those previously reported in the dark cold cloud TMC-1. This suggests that the three isomers are likely formed through gas-phase chemistry from common precursors, possibly unsaturated hydrocarbons (CH3CCH and CH2CCH2) that react with the cyanide radical (CN). The rich nitrile feedstock found towards G+0.693-0.027 confirms that interstellar chemistry is able to synthesize in space molecular species that could drive the prebiotic chemistry of the RNA-world