2,651 research outputs found
Controle da podridão cinzenta da maçã por produtos naturais biologicamente ativos
IndexaciĂłn: Web of Science; ScieloBiorend SC (chitosan), BC-1000 EC (grapefruit extract plus bioflavonoids) and ECO-100 SC (bioflavonoids plus organic acids, citric phytoalexins, fatty acids, glycerides and sugars), respectively, suppressed grey rot of apple caused by B. cinerea by 80.1%, 79.0% and 76.5% when used as post-harvest treatments under controlled conditions. When applied as combined pre- and post-harvest treatments Biorend SC inhibited fruit rot by 49.9 %, while BC-1000 EC and ECO-100 SC were ineffective. None of the products inhibited fruit rot when applied as pre-harvest treatments under controlled conditions or as post-harvest treatments under commercial conditions. The algal polysaccharide ulvan used in post-harvest treatments suppressed grey rot by 56.0% under controlled conditions, but had no inhibitory effect on combined pre- and post-harvest treatments. The inability of products to activate defense mechanisms (chitinase and peroxidase) of fruits was consistent with the unsuccessful control of rot by pre-harvest treatment. The results suggest that the natural products used have potential for use in integrated management of Botrytis rot when applied after harvest.Biorend SC (quitosana), BC-1000 EC (extrato de toranja mais flavonĂłides), e ECO-100 SC (bioflavonĂłides mais ácidos orgânicos, fitoalexinas cĂtricas, ácidos graxos glicerĂdeos e açúcares) inibiram em 80,1%, 79,0% e 76,5%, respectivamente, a podridĂŁo causada por Botrytis cinerea quando utilizados no tratamento pĂłs-colheita de frutos de maçã sob condições controladas.Tratamento combinado de Biorend SC, com aplicação tanto em prĂ© como no pĂłs-colheita, proporcionou 49,9% de inibição da podridĂŁo, enquanto BC-1000 e ECO-100 EC nĂŁo foram efetivos. Nenhum desses produtos inibiu a podridĂŁo cinzenta, quando utilizados em tratamento de prĂ©-colheita em condições controladas ou em tratamento de pĂłs-colheita em condições comerciais. O polissacarĂdeo algal ulvana, utilizado nos tratamentos de pĂłs-colheita, reduziu em 56% a podridĂŁo cinzenta das maçãs em condições controladas, mas nĂŁo teve efeito inibitĂłrio nos tratamentos combinados de prĂ© e pĂłs-colheita. A incapacidade dos produtos em ativar mecanismos de defesa (quitinases e peroxidases) nos frutos, apĂłs o tratamento em prĂ©-colheita, foi consistente com a falta de controle da podridĂŁo nesse tipo de ensaio. Pelos resultados, sugere-se que os produtos naturais utilizados apresentam potencial para a utilização no manejo integrado da podridĂŁo de Botrytis quando aplicados em pĂłs-colheita.http://ref.scielo.org/kcxb9
The potential impact of enhanced hygienic measures during the COVID-19 outbreak on hospital-acquired infections: A pragmatic study in neurological units
Objective: Hospital-acquired infections (HAIs) are frequent complications among acute patients hospitalized in neurological units, especially among those hospitalized for stroke. This study aimed to investigate if enhanced hygienic measures, including the systematic use of personal protective equipment (PPE), determined a decrease in HAI during the recent COVID-19 outbreak in “COVID-free” neurological units. Methods: Patients hospitalized in neurology and stroke units of Policlinico Umberto I Hospital in Rome from March 8, 2020 and discharged prior to May 31, 2020 were included in the study and compared with patients hospitalized during the same period in 2019. Results: A total of 319 patients were included in the study (n = 103 in 2020, n = 216 in 2019). Among patients hospitalized in 2019, the incidence of HAIs was 31.5% (95% confidence interval (CI): 0.25–0.38), compared with 23.3% (95% CI: 0.15–0.32) in 2020 (p = 0.12). Multivariable logistic regression showed that hospitalization during 2020 was independently associated with a lower risk of HAIs (odds ratio: 0.34, 95% CI:0.16–0.71, p = 0.004). Poisson regression models showed that hospitalization during 2020 was also independently associated with both a lower number of HAIs (relative risk [RR]: 0.56, 95% CI:0.38–0.81, p = 0.01) and a lower number of prescribed antibiotics per patient (RR: 0.66, 95% CI: 0.49–0.87, p = 0.02). Conclusion: Our study design provides evidence regarding the impact of stricter hygienic measures, such as increased PPE use, on HAIs. Larger studies are needed to support the extension of preventive measures even after the COVID-19 outbreak in order to limit the occurrence of HAIs
Study of the diffuse gamma-ray emission from the Galactic plane with ARGO-YBJ
The events recorded by ARGO-YBJ in more than five years of data collection
have been analyzed to determine the diffuse gamma-ray emission in the Galactic
plane at Galactic longitudes 25{\deg} < l < 100{\deg} and Galactic latitudes .
The energy range covered by this analysis, from ~350 GeV to ~2 TeV, allows the
connection of the region explored by Fermi with the multi-TeV measurements
carried out by Milagro. Our analysis has been focused on two selected regions
of the Galactic plane, i.e., 40{\deg} < l < 100{\deg} and 65{\deg} < l <
85{\deg} (the Cygnus region), where Milagro observed an excess with respect to
the predictions of current models. Great care has been taken in order to mask
the most intense gamma-ray sources, including the TeV counterpart of the Cygnus
cocoon recently identified by ARGO-YBJ, and to remove residual contributions.
The ARGO-YBJ results do not show any excess at sub-TeV energies corresponding
to the excess found by Milagro, and are consistent with the predictions of the
Fermi model for the diffuse Galactic emission. From the measured energy
distribution we derive spectral indices and the differential flux at 1 TeV of
the diffuse gamma-ray emission in the sky regions investigated.Comment: 11 pages, 6 figures, published in AP
4.5 years multi-wavelength observations of Mrk 421 during the ARGO-YBJ and Fermi common operation time
We report on the extensive multi-wavelength observations of the blazar
Markarian 421 (Mrk 421) covering radio to gamma-rays, during the 4.5 year
period of ARGO-YBJ and Fermi common operation time, from August 2008 to
February 2013. In particular, thanks to the ARGO-YBJ and Fermi data, the whole
energy range from 100 MeV to 10 TeV is covered without any gap. In the
observation period, Mrk 421 showed both low and high activity states at all
wavebands. The correlations among flux variations in different wavebands were
analyzed. Seven large flares, including five X-ray flares and two GeV gamma-ray
flares with variable durations (3-58 days), and one X-ray outburst phase were
identified and used to investigate the variation of the spectral energy
distribution with respect to a relative quiescent phase. During the outburst
phase and the seven flaring episodes, the peak energy in X-rays is observed to
increase from sub-keV to few keV. The TeV gamma-ray flux increases up to
0.9-7.2 times the flux of the Crab Nebula. The behavior of GeV gamma-rays is
found to vary depending on the flare, a feature that leads us to classify
flares into three groups according to the GeV flux variation. Finally, the
one-zone synchrotron self-Compton model was adopted to describe the emission
spectra. Two out of three groups can be satisfactorily described using injected
electrons with a power-law spectral index around 2.2, as expected from
relativistic diffuse shock acceleration, whereas the remaining group requires a
harder injected spectrum. The underlying physical mechanisms responsible for
different groups may be related to the acceleration process or to the
environment properties.Comment: 17 pages, 9 figures, 5 tables, Accepted for publication in ApJ
The variable finesse locking technique
Virgo is a power recycled Michelson interferometer, with 3 km long Fabry-Perot cavities in the arms. The locking of the interferometer has been obtained with an original lock acquisition technique. The main idea is to lock the instrument away from its working point. Lock is obtained by misaligning the power recycling mirror and detuning the Michelson from the dark fringe. In this way, a good fraction of light escapes through the antisymmetric port and the power build-up inside the recycling cavity is extremely low. The benefit is that all the degrees of freedom are controlled when they are almost decoupled, and the linewidth of the recycling cavity is large. The interferometer is then adiabatically brought on to the dark fringe. This technique is referred to as variable finesse, since the recycling cavity is considered as a variable finesse Fabry-Perot. This technique has been widely tested and allows us to reach the dark fringe in few minutes, in an essentially deterministic way
Atmospheric neutrino induced muons in the MACRO detector
A measurement of the flux of neutrino-induced muons using the MACRO detector
is presented. Different event topologies, corresponding to different neutrino
parent energies can be detected. The upward throughgoing muon sample is the
larger event sample. The observed upward-throughgoing muons are 26% fewer than
expected and the zenith angle distribution does not fit with the expected one.
Assuming neutrino oscillations, both measurements suggest maximum mixing and
Dm2 of a few times 10-3 eV2. The other samples are due to the internally
produced events and to upward-going stopping muons. These data show a regular
deficit of observed events in each angular bin, as expected assuming neutrino
oscillations with maximum mixing, in agreement with the analysis of the
upward-throughgoing muon sample.Comment: 7 pages 6 figures to appear in the proceedings of XVIII International
Conference on Neutrino Physics and Astrophysics (Neutrino'98), Takayama,
Japan 4-9 June, 199
Practical and clinical utility of non-invasive vagus nerve stimulation (nVNS) for the acute treatment of migraine. A post hoc analysis of the randomized, sham-controlled, double-blind PRESTO trial
Background: The PRESTO study of non-invasive vagus nerve stimulation (nVNS; gammaCore®) featured key primary and secondary end points recommended by the International Headache Society to provide Class I evidence that for patients with an episodic migraine, nVNS significantly increases the probability of having mild pain or being pain-free 2 h post stimulation. Here, we examined additional data from PRESTO to provide further insights into the practical utility of nVNS by evaluating its ability to consistently deliver clinically meaningful improvements in pain intensity while reducing the need for rescue medication. Methods: Patients recorded pain intensity for treated migraine attacks on a 4-point scale. Data were examined to compare nVNS and sham with regard to the percentage of patients who benefited by at least 1 point in pain intensity. We also assessed the percentage of attacks that required rescue medication and pain-free rates stratified by pain intensity at treatment initiation. Results: A significantly higher percentage of patients who used acute nVNS treatment (n = 120) vs sham (n = 123) reported a ≥ 1-point decrease in pain intensity at 30 min (nVNS, 32.2%; sham, 18.5%; P = 0.020), 60 min (nVNS, 38.8%; sham, 24.0%; P = 0.017), and 120 min (nVNS, 46.8%; sham, 26.2%; P = 0.002) after the first attack. Similar significant results were seen when assessing the benefit in all attacks. The proportion of patients who did not require rescue medication was significantly higher with nVNS than with sham for the first attack (nVNS, 59.3%; sham, 41.9%; P = 0.013) and all attacks (nVNS, 52.3%; sham, 37.3%; P = 0.008). When initial pain intensity was mild, the percentage of patients with no pain after treatment was significantly higher with nVNS than with sham at 60 min (all attacks: nVNS, 37.0%; sham, 21.2%; P = 0.025) and 120 min (first attack: nVNS, 50.0%; sham, 25.0%; P = 0.018; all attacks: nVNS, 46.7%; sham, 30.1%; P = 0.037). Conclusions: This post hoc analysis demonstrated that acute nVNS treatment quickly and consistently reduced pain intensity while decreasing rescue medication use. These clinical benefits provide guidance in the optimal use of nVNS in everyday practice, which can potentially reduce use of acute pharmacologic medications and their associated adverse events. Trial registration: ClinicalTrials.gov identifier: NCT02686034
Potencial do flavedo (epicarpo) de Citrus aurantifolia cv. Tahiti no controle do bolor verde e da antracnose em citros
Extracorporeal membrane oxygenation in children with COVID-19: preliminary report from the collaborative EuroELSO prospective study.
Perioperative Medicine: Efficacy, Safety and Outcome (Anesthesiology/Intensive Care
Introducing the “analogs for Venus’ geologically recent surfaces” initiative: an opportunity for identifying and analyzing recently active volcano-tectonic areas of Venus trough a comparative study with terrestrial analogs
Several missions to Venus have been recently selected for launch [1–6], opening a new era for the exploration of the planet. One of the key questions that the future missions need to address is whether Venus is presently volcanically active [7–15]. Studying areas of active volcanism and tectonism on Venus is crucial to reveal clues about the geologic past of the planet, as well as provide information about the volatile content of its interior and the formation of its dense atmosphere. The “Analogsfor VENus’ GEologically Recent Surfaces” (AVENGERS) initiative aims to build a comprehensive database of terrestrial analog sites for the comparative study of recent and possibly on- going volcanic activity on Venus. Besides its scientific relevance, the AVENG- ERS initiative also acts as a bridge for international scientific collaboration, including the leadership and/or team members from the currently selected missions to Venus
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