2,017 research outputs found

    Black soldier fly as a New chitin source: Extraction, purification and molecular/structural characterization

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    Black Soldier Fly (BSF) represents a potential chitin source that has not been fully explored in terms of characterization, extraction, and purification. In this study, different chemical and enzymatic protocols with or without pre-treatment (ultrasonication and mechanochemical milling) for chitin extraction were tested. Chitin was then accurately quantified and characterized from a molecular and structural point of view by UPLC-MS, XRD, and ESEM, and compared with chitin from shrimp shells. BSF chitin was more recalcitrant than shrimp chitin during extraction and purification, due to the strong binding of chitin to proteins. Indeed, the purity of shrimp chitin was 88.3g/100g of extract, while BSF chitin purity was 47.6‚Äď79.9g/100g. Furthermore, the chitin-bound proteins had a defined amino acid composition; their binding was also confirmed by structural characterization. Therefore, the efficiency of each step of the extraction process needs to be critically evaluated to adapt the methods used for crustaceans to insect biomass

    Multimessenger Characterization of Markarian 501 during Historically Low X-Ray and ő≥-Ray Activity

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    We study the broadband emission of Mrk 501 using multiwavelength observations from 2017 to 2020 performed with a multitude of instruments, involving, among others, MAGIC, Fermi's Large Area Telescope (LAT), NuSTAR, Swift, GASP-WEBT, and the Owens Valley Radio Observatory. Mrk 501 showed an extremely low broadband activity, which may help to unravel its baseline emission. Nonetheless, significant flux variations are detected at all wave bands, with the highest occurring at X-rays and very-high-energy (VHE) ő≥ -rays. A significant correlation (>3 ŌÉ ) between X-rays and VHE ő≥ -rays is measured, supporting leptonic scenarios to explain the variable parts of the emission, also during low activity. This is further supported when we extend our data from 2008 to 2020, and identify, for the first time, significant correlations between the Swift X-Ray Telescope and Fermi-LAT. We additionally find correlations between high-energy ő≥ -rays and radio, with the radio lagging by more than 100 days, placing the ő≥ -ray emission zone upstream of the radio-bright regions in the jet. Furthermore, Mrk 501 showed a historically low activity in X-rays and VHE ő≥ -rays from mid-2017 to mid-2019 with a stable VHE flux (>0.2 TeV) of 5% the emission of the Crab Nebula. The broadband spectral energy distribution (SED) of this 2 yr long low state, the potential baseline emission of Mrk 501, can be characterized with one-zone leptonic models, and with (lepto)-hadronic models fulfilling neutrino flux constraints from IceCube. We explore the time evolution of the SED toward the low state, revealing that the stable baseline emission may be ascribed to a standing shock, and the variable emission to an additional expanding or traveling shock

    Farmers concerns in relation to organic livestock production

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    The study describes organic producers‚Äô perceptions of organic livestock production, product commercialisation, use of contentious inputs such as allopathic antibiotics, antiparasitics and vitamins and bedding materials availability in Mediterranean (MED) and North/Western European (NWE) countries. A total of 426 MED (46.2%) and NWE (53.8%) responses were analysed revealing more difficulty finding information on alternatives to antiparasitics and antibiotics than on bedding materials. They identified ‚Äėfeeding/nutrition‚Äô, ‚Äėanimal health‚Äô and ‚Äėwelfare‚Äô as the most relevant topics in their farms. Whereas ruminants and monogastrics farmers in the NWE region also indicated ‚Äėorganic regulation‚Äô as relevant, farmers rearing ruminant species in the MED region identified farm profitability and commercialisation. Farmers still mainly relied in conventional treatments but they often applied phytotherapy, although >61% of the participants did not treat their animals in the last year. If treated, most of them administered on average one course of antibiotic treatment per animal (>62%). In the MED region, the main sources of information on alternative treatments were veterinarians (>60%) and the Internet (>32%). In the NWE region, it was other farmers for producers including ruminant species (>63%) and veterinarians (>77%) for monogastric farmers. In the NWE region, direct commercialisation and through a cooperative and/or food industry were¬†the most frequent channel used; while, in the MED region, they were the¬†food industry and/or direct commercialisation. In conclusion, this survey provides novel cross-European insights into organic livestock producers' concerns. A particular value of the survey is that MED countries, which are often underrepresented, were well sampled

    Performance of the joint LST-1 and MAGIC observations evaluated with Crab Nebula data

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    International audienceAims. LST-1, the prototype of the Large-Sized Telescope for the upcoming Cherenkov Telescope Array Observatory, is concluding its commissioning in Observatorio del Roque de los Muchachos on the island of La Palma. The proximity of LST-1 (Large-Sized Telescope 1) to the two MAGIC (Major Atmospheric Gamma Imaging Cherenkov) telescopes permits observations of the same gamma-ray events with both systems. Methods. We describe the joint LST-1+MAGIC analysis pipeline and use simultaneous Crab Nebula observations and Monte Carlo simulations to assess the performance of the three-telescope system. The addition of the LST-1 telescope allows the recovery of events in which one of the MAGIC images is too dim to survive analysis quality cuts. Results. Thanks to the resulting increase in the collection area and stronger background rejection, we find a significant improvement in sensitivity, allowing the detection of 30% weaker fluxes in the energy range between 200 GeV and 3 TeV. The spectrum of the Crab Nebula, reconstructed in the energy range ~60 GeV to ~10 TeV, is in agreement with previous measurements

    The UHECR-FR0 Radio Galaxy Connection: A Multi-Messenger Study of Energy Spectra/Composition Emission and Intergalactic Magnetic Field Propagation

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    This study investigates low luminosity Fanaroff-Riley Type 0 (FR0) radio galaxies as a potentially significant source of ultra-high energy cosmic rays (UHECRs). Due to their much higher prevalence in the local universe compared to more powerful radio galaxies (about five times more than FR-1s), FR0s may provide a substantial fraction of the total UHECR energy density. To determine the nucleon composition and energy spectrum of UHECRs emitted by FR0 sources, simulation results from CRPropa3 are fit to Pierre Auger Observatory data. The resulting emission spectral indices, rigidity cutoffs, and nucleon fractions are compared to recent Auger results. The FR0 simulations include the approximately isotropic distribution of FR0 galaxies and various intergalactic magnetic field configurations (including random and structured fields) and predict the fluxes of secondary photons and neutrinos produced during UHECR propagation through cosmic photon backgrounds. This comprehensive simulation allows for investigating the properties of the FR0 sources using observational multi-messenger data.Comment: PoS 444 (38th ICRC) 151

    Efficacy and Safety of Carbapenems vs New Antibiotics for Treatment of Adult Patients With Complicated Urinary Tract Infections: A Systematic Review and Meta-analysis

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    This systematic review and meta-analysis evaluated the clinical efficacy and safety of carbapenems for the treatment of complicated urinary tract infections (cUTIs), with the comparators being new antibiotics evaluated for this indication. We searched 13 electronic databases for published randomized controlled trials (RCTs) and completed and/or ongoing trials. The search terms were developed using the Population, Intervention, Comparison, Outcomes, and Study framework. Pooled efficacy estimates of composite cure (clinical success and microbiological eradication) favored the new antibiotic groups, although this was not statistically significant (risk ratio [RR], 0.91; 95% CI, 0.79-1.04). A pooled estimate examining clinical response alone showed no difference between treatment arms (RR, 1.00; 95% CI, 0.96-1.05), however, new antibiotic treatments were superior to carbapenems for microbiological response (RR, 0.85; 95% CI, 0.79-0.91). New antibiotic treatments demonstrated a superior microbiological response compared with carbapenems in clinical trials of cUTI, despite an absence of carbapenem resistance. However, it is noteworthy that the clinical response and safety profile of new antibiotics were not different from those of carbapenems.© The Author(s) 2020. Published by Oxford University Press on behalf of Infectious Diseases Society of America

    Aging-related predictive factors for oxygenation improvement and mortality in COVID-19 and acute respiratory distress syndrome (ARDS) patients exposed to prone position: A multicenter cohort study

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    Background: Elderly patients are more susceptible to Coronavirus Disease-2019 (COVID-19) and are more likely to develop it in severe forms, (e.g., Acute Respiratory Distress Syndrome [ARDS]). Prone positioning is a treatment strategy for severe ARDS; however, its response in the elderly population remains poorly understood. The main objective was to evaluate the predictive response and mortality of elderly patients exposed to prone positioning due to ARDS-COVID-19. Methods: This retrospective multicenter cohort study involved 223 patients aged ‚Č• 65 years, who received prone position sessions for severe ARDS due to COVID-19, using invasive mechanical ventilation. The PaO2/FiO2 ratio was used to assess the oxygenation response. The 20-point improvement in PaO2/FiO2 after the first prone session was considered for good response. Data were collected from electronic medical records, including demographic data, laboratory/image exams, complications, comorbidities, SAPS III and SOFA scores, use of anticoagulants and vasopressors, ventilator settings, and respiratory system mechanics. Mortality was defined as deaths that occurred until hospital discharge. Results: Most patients were male, with arterial hypertension and diabetes mellitus as the most prevalent comorbidities. The non-responders group had higher SAPS III and SOFA scores, and a higher incidence of complications. There was no difference in mortality rate. A lower SAPS III score was a predictor of oxygenation response, and the male sex was a risk predictor of mortality. Conclusion: The present study suggests the oxygenation response to prone positioning in elderly patients with severe COVID-19-ARDS correlates with the SAPS III score. Furthermore, the male sex is a risk predictor of mortality

    Consensus clustering methodology to improve molecular stratification of non-small cell lung cancer

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    Abstract Recent advances in machine learning research, combined with the reduced sequencing costs enabled by modern next-generation sequencing, paved the way to the implementation of precision medicine through routine multi-omics molecular profiling of tumours. Thus, there is an emerging need of reliable models exploiting such data to retrieve clinically useful information. Here, we introduce an original consensus clustering approach, overcoming the intrinsic instability of common clustering methods based on molecular data. This approach is applied to the case of non-small cell lung cancer (NSCLC), integrating data of an ongoing clinical study (PROMOLE) with those made available by The Cancer Genome Atlas, to define a molecular-based stratification of the patients beyond, but still preserving, histological subtyping. The resulting subgroups are biologically characterized by well-defined mutational and gene-expression profiles and are significantly related to disease-free survival (DFS). Interestingly, it was observed that (1) cluster B, characterized by a short DFS, is enriched in KEAP1 and SKP2 mutations, that makes it an ideal candidate for further studies with inhibitors, and (2) over- and under-representation of inflammation and immune systems pathways in squamous-cell carcinomas subgroups could be potentially exploited to stratify patients treated with immunotherapy
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