473 research outputs found

    Bringing radiology to patient's home using mobile equipment : a weapon to fight COVID-19 pandemic

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    Because of coronavirus disease 2019 (COVID-19) high contagiousness, it is crucial to identify and promptly isolate COVID-19 patients. In this context, chest imaging examinations, in particular chest x-ray (CXR), can play a pivotal role in different settings, to triage in case of unavailability, delay of or first negative result of reverse transcriptase-polymerase chain reaction (RT-PCR), and to stratify disease severity. Considering the need to reduce, as much as possible, hospital admission of patients with suspected or confirmed infection, the use of mobile x-ray equipment could represent a safe approach. We picture a potential sequence of events, involving a team composed by a radiographer and a nurse, going to patient's home to perform CXR, nasopharyngeal swab (and, if needed, also a blood sample), with fast radiologist tele-reporting, and resulting patient management approach (home isolation or emergency room admission, when needed). This approach brings healthcare to patient's home, reducing the risk of infected subjects referring to family doctors' office or emergency departments, and strengthening community medicine while maintaining a strong connection with radiology departments

    Search for a Radio Pulsar in the Remnant of Supernova 1987A

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    We have observed the remnant of supernova SN~1987A (SNR~1987A), located in the Large Magellanic Cloud (LMC), to search for periodic and/or transient radio emission with the Parkes 64\,m-diameter radio telescope. We found no evidence of a radio pulsar in our periodicity search and derived 8σ\sigma upper bounds on the flux density of any such source of 31 μ31\,\muJy at 1.4~GHz and 21 μ21\,\muJy at 3~GHz. Four candidate transient events were detected with greater than 7σ7\sigma significance, with dispersion measures (DMs) in the range 150 to 840\,cm−3 ^{-3}\,pc. For two of them, we found a second pulse at slightly lower significance. However, we cannot at present conclude that any of these are associated with a pulsar in SNR~1987A. As a check on the system, we also observed PSR~B0540−-69, a young pulsar which also lies in the LMC. We found eight giant pulses at the DM of this pulsar. We discuss the implications of these results for models of the supernova remnant, neutron star formation and pulsar evolution.Comment: 7 pages, 3 figures, 2 tables. Accepted for publication in MNRA

    Vibration stability of Orion laser facility

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    This is the author accepted manuscript. The final version is available from Thomas Telford (ICE Publishing) via the DOI in this record.In 2005 the UK Ministry of Defence awarded a contract for construction of the Orion laser facility at the Atomic Weapons Establishment (AWE). Orion delivers a power density of 1021W/cm2 on a 5 µm target, making it a world class facility for the study of high energy density physics. The ability to target to such high precision depends on ‘stability’ of the building and internal structures with respect to thermal expansion and vibrations. This paper concerns experimental activities supporting prediction and evaluation of the minute vibrations against a ‘budget’ comprising effects of all vibration sources, internal and external, and the sequence of experimental campaigns and signal evaluation that fed into this process. This involved a sequence of dynamics-based measurements of: • foundation pile stiffness • vibration propagation from both controlled and uncontrolled sources at stages during the construction and finally • evaluation of vibration levels in the as-built facility due to internal machinery and the few external vibration sources passing through the sophisticated vibration barrier. The approach focused on time series of vibrations in the design phase, and on evaluation of statistical properties of displacement power spectral density functions

    Predictive Modeling of Envelope Flood Extents Using Geomorphic and Climatic-Hydrologic Catchment Characteristics

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    A topographic index (flood descriptor) that combines the scaling of bankfull depth with morphology was shown to describe the tendency of an area to be flooded. However, this approach depends on the quality and availability of flood maps and assumes that outcomes can be directly extrapolated and downscaled. This work attempts to relax these problems and answer two questions: (1) Can functional relationships be established between a flood descriptor and geomorphic and climatic-hydrologic catchment characteristics? (2) If so, can they be used for low-complexity predictive modeling of envelope flood extents? Linear stepwise and random forest regressions are developed based on classification outcomes of a flood descriptor, using high-resolution flood modeling results as training benchmarks, and on catchment characteristics. Elementary catchments of four river basins in Europe (Thames, Weser, Rhine, and Danube) serve as training data set, while those of the Rh\uf4ne river basin in Europe serve as testing data set. Two return periods are considered, the 10- and 10,000-year. Prediction of envelope flood extents and flood-prone areas show that both models achieve high hit rates with respect to testing benchmarks. Average values were found to be above 60% and 80% for the 10- and the 10,000-year return periods, respectively. In spite of a moderate to high false discovery rate, the critical success index value was also found to be moderate to high. It is shown that by relating classification outcomes to catchment characteristics, the prediction of envelope flood extents may be achieved for a given region, including ungauged basins

    Mixed nodule infection in Sinorhizobium meliloti-medicago sativa symbiosis suggest the presence of cheating behavior

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    In the symbiosis between rhizobia and legumes, host plants can forms ymbiotic root nodules with multiple rhizobial strains, potentially showing different symbiotic performances in nitrogen fixation. Here, we investigated the presence of mixed nodules, containing rhizobia with different degrees of mutualisms, and evaluate their relative fitness in the Sinorhizobium meliloti-Medicago sativa model symbiosis. We used three S. meliloti strains, the mutualist strains Rm1021 and BL225C and the non-mutualist AK83. We performed competition experiments involving both in vitro and in vivo symbiotic assays with M. sativa host plants. We show the occurrence of a high number (from 27 to 100%) of mixed nodules with no negative effect on both nitrogen fixation and plant growth. The estimation of the relative fitness as non-mutualist/mutualist ratios in single nodules shows that in some nodules the non-mutualist strain efficiently colonized root nodules along with the mutualist ones. In conclusion, we can support the hypothesis that in S. meliloti-M. sativa symbiosis mixed nodules are formed and allow non-mutualist or less-mutualist bacterial partners to be less or not sanctioned by the host plant, hence allowing a potential form of cheating behavior to be present in the nitrogen fixing symbiosis

    Dust Production and Particle Acceleration in Supernova 1987A Revealed with ALMA

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    Supernova (SN) explosions are crucial engines driving the evolution of galaxies by shock heating gas, increasing the metallicity, creating dust, and accelerating energetic particles. In 2012 we used the Atacama Large Millimeter/Submillimeter Array to observe SN 1987A, one of the best-observed supernovae since the invention of the telescope. We present spatially resolved images at 450um, 870um, 1.4mm, and 2.8mm, an important transition wavelength range. Longer wavelength emission is dominated by synchrotron radiation from shock-accelerated particles, shorter wavelengths by emission from the largest mass of dust measured in a supernova remnant (>0.2Msun). For the first time we show unambiguously that this dust has formed in the inner ejecta (the cold remnants of the exploded star's core). The dust emission is concentrated to the center of the remnant, so the dust has not yet been affected by the shocks. If a significant fraction survives, and if SN 1987A is typical, supernovae are important cosmological dust producers.Comment: ApJL accepte

    Evolutionary leap in large-scale flood risk assessment needed

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    Current approaches for assessing large-scale flood risks contravene the fundamental principles of the flood risk system functioning because they largely ignore basic interactions and feedbacks between atmosphere, catchments, river-floodplain systems and socio-economic processes. As a consequence, risk analyses are uncertain and might be biased. However, reliable risk estimates are required for prioritizing national investments in flood risk mitigation or for appraisal and management of insurance portfolios. We review several examples of process interactions and highlight their importance in shaping spatio-temporal risk patterns. We call for a fundamental redesign of the approaches used for large-scale flood risk assessment. They need to be capable to form a basis for large-scale flood risk management and insurance policies worldwide facing the challenge of increasing risks due to climate and global change. In particular, implementation of the European Flood Directive needs to be adjusted for the next round of flood risk mapping and development of flood risk management plans focussing on methods accounting for more process interactions in flood risk systems

    Revising acute care systems and processes to improve breastfeeding and maternal postnatal health: a pre and post intervention study in one English maternity unit

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    Background Most women in the UK give birth in a hospital labour ward, following which they are transferred to a postnatal ward and discharged home within 24 to 48 hours of the birth. Despite policy and guideline recommendations to support planned, effective postnatal care, national surveys of women’s views of maternity care have consistently found in-patient postnatal care, including support for breastfeeding, is poorly rated. Methods Using a Continuous Quality Improvement approach, routine antenatal, intrapartum and postnatal care systems and processes were revised to support implementation of evidence based postnatal practice. To identify if implementation of a multi-faceted QI intervention impacted on outcomes, data on breastfeeding initiation and duration, maternal health and women’s views of care, were collected in a pre and post intervention longitudinal survey. Primary outcomes included initiation, overall duration and duration of exclusive breastfeeding. Secondary outcomes included maternal morbidity, experiences and satisfaction with care. As most outcomes of interest were measured on a nominal scale, these were compared pre and post intervention using logistic regression. Results Data were obtained on 741/1160 (64%) women at 10 days post-birth and 616 (54%) at 3 months post-birth pre-intervention, and 725/1153 (63%) and 575 (50%) respectively postintervention. Post intervention there were statistically significant differences in the initiation (p = 0.050), duration of any breastfeeding (p = 0.020) and duration of exclusive breastfeeding to 10 days (p = 0.038) and duration of any breastfeeding to three months (p = 0.016). Post intervention, women were less likely to report physical morbidity within the first 10 days of birth, and were more positive about their in-patient care. Conclusions It is possible to improve outcomes of routine in-patient care within current resources through continuous quality improvement

    Lipids in the Interventricular septum (SEP) as promising indicators of cardiovascular (CV) events in hyperglycemic (HG) patients: an in vivo 1H-MRS study

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    Proton magnetic resonance spectroscopy (1H-MRS) can detect and quantify lipid accumulation in specific myocardial or peri-myocardial districts. Thirty-three patients (20M/13F; BMI 26\ub14 kg/m2; 64\ub110 yrs) with suspect of CV diseases underwent 1.5-T 1H-MRS using a water-suppressed chemical-shift imaging sequence to quantify the lipid profile of SEP, epicardial (EAT), pericardial (PAT), and subcutaneous (SAT) adipose tissues. The integral of the lipid peaks at 0.9, 1.3, 2.0, 5.3 ppm was measured as percentage over the total amount of lipids (Table). A subgroup of 15 subjects were identified as hyperglycemic (HG = 12 impaired-fasting-glucose + 3 diabetics: 121\ub126 mg/dL). Bulk methylene (1.3 ppm) of SEP was higher in HG vs other patients (P=0.047). In HG patients, SEP was positively correlated to glucose, visceral fat, C-reactive protein (Spearman \uf072>0.63, P<0.018); EAT was positively correlated to visceral fat, age, body weight, and inversely to muscular-, fat free-, bone mass (Pearson \uf072<|0.53|, P<0.039). In all subjects, the main lipid peaks correlated with metabolic parameters. 1H-MRS allowed to measure lipid peaks in different adipose compartments with cardiometabolic relevance. SEP resulted a myocardial site associated with biomarkers of secondary heart events in pre/diabetic patients at higher risk of CV episodes. High SEP fat may be proposed as a marker of future CV events

    Technique, protocols and adverse reactions for contrast-enhanced spectral mammography (CESM ): a systematic review

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    We reviewed technical parameters, acquisition protocols and adverse reactions (ARs) for contrast-enhanced spectral mammography (CESM). A systematic search in databases, including MEDLINE/EMBASE, was performed to extract publication year, country of origin, study design; patients; mammography unit/vendor, radiation dose, low-/high-energy tube voltage; contrast molecule, concentration and dose; injection modality, ARs and acquisition delay; order of views; examination time. Of 120 retrieved articles, 84 were included from 22 countries (September 2003-January 2019), totalling 14012 patients. Design was prospective in 44/84 studies (52%); in 70/84 articles (83%), a General Electric unit with factory-set kVp was used. Per-view average glandular dose, reported in 12/84 studies (14%), ranged 0.43-2.65\u2009mGy. Contrast type/concentration was reported in 79/84 studies (94%), with Iohexol 350 mgI/mL mostly used (25/79, 32%), dose and flow rate in 72/84 (86%), with 1.5 mL/kg dose at 3\u2009mL/s in 62/72 studies (86%). Injection was described in 69/84 articles (82%), automated in 59/69 (85%), manual in 10/69 (15%) and flush in 35/84 (42%), with 10-30 mL dose in 19/35 (54%). An examination time\u2009<\u200910\u2009min was reported in 65/84 studies (77%), 120 s acquisition delay in 65/84 (77%) and order of views in 42/84 (50%) studies, beginning with the craniocaudal view of the non-suspected breast in 7/42 (17%). Thirty ARs were reported by 14/84 (17%) studies (26 mild, 3 moderate, 1 severe non-fatal) with a pooled rate of 0.82% (fixed-effect model). Only half of CESM studies were prospective; factory-set kVp, contrast 1.5 mL/kg at 3\u2009mL/s and 120 s acquisition delay were mostly used; only 1 severe AR was reported. CESM protocol standardisation is advisable
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