450 research outputs found

    A new engineering approach to predict the long-term hydrostatic strength of unplasticized poly(vinyl chloride) pipes

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    Extruded polymer pipes are qualified using pressurized pipe tests. With these tests the long-term hydrostatic strength is determined by subjecting the pipes to an internal pressure, while measuring the time-to-failure. Although these tests can be accelerated (at higher temperatures), they remain time consuming and require a spacious experimental setup. To circumvent this costly method a model based approach is proposed by which the long-term hydrostatic strength is predicted. Using short term measurements, the input parameters for this approach can be determined. In this engineering approach the effects of physical aging are included. The approach is capable to quantitatively predict the (long-term) failure time of pipe sections under internal pressure

    Comparison of potato varieties between seasons and their potential for acrylamide formation

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    BACKGROUND: Acrylamide is a probable human carcinogen produced during food preparation, including frying of potato products. The aim of this study was to investigate the impact of seasonal variation on tuber composition and its acrylamide generation potential. RESULTS: The chemical composition of potato varieties used respectively for French fry (Bintje and Ramos) and crisp (Lady Rosetta and Saturna) production was studied throughout a storage period of 9 months during two growing seasons (2003 and 2004), in addition to their acrylamide generation potential during preparation of French fries. A significant impact of variable climatological conditions on the reducing sugar, dry matter, total free amino acid and free asparagine contents of tubers was observed. Exceptionally warm summers gave rise to a lower reducing sugar content (expressed on a dry matter basis) and thus a lower susceptibility to acrylamide generation during frying. CONCLUSION: It cannot be excluded that potato growers and the potato-processing industry are confronted with some harvests that are more prone to acrylamide generation than others owing to climatological variability, thus confirming the importance of a multifactorial approach to mitigate acrylamide generation in potato products.</p

    Cranial ultrasound findings in preterm germinal matrix haemorrhage, sequelae and outcome

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    Germinal matrix-intraventricular haemorrhage (GMH-IVH), periventricular haemorrhagic infarction (PHI) and its complication, post-haemorrhagic ventricular dilatation (PHVD), are still common neonatal morbidities in preterm infants that are highly associated with adverse neurodevelopmental outcome. Typical cranial ultrasound (CUS) findings of GMH-IVH, PHI and PHVD, their anatomical substrates and underlying mechanisms are discussed in this paper. Furthermore, we propose a detailed descriptive classification of GMH-IVH and PHI that may improve quality of CUS reporting and prediction of outcome in infants suffering from GMH-IVH/PHI

    High delayed and missed injury rate after inter-hospital transfer of severely injured trauma patients

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    PURPOSE: Missed injuries are reported in 1.3-65% of all admitted trauma patients. The severely injured patient that needs a higher level of care which requires an inter-hospital transfer has an increased risk for missed injuries. The aim of this study was to establish the incidence and clinical relevance of missed injuries in severely injured patients who require inter-hospital transfer to a level 1 trauma center. METHODS: All patients with an Injury Severity Score (ISS) ≥ 16 transferred to the University Medical Center Groningen (UMCG) between January 2010 and July 2015 were included. Data were obtained from a prospective trauma database and supplemented with information from the patient records. A delayed diagnosis was defined as any injury detected within the first 24 h after the initial trauma, with or without a tertiary survey. Missed diagnoses were defined as any injury diagnosed after 24 h following trauma. RESULTS: Two hundred and fifty-one trauma patients were included. A total of 88 patients (35%) were found to have ≥ 1 new diagnoses with 65 (26%) patients that had 1 or more delayed diagnoses and 23 (9.2%) patients had 1 or more missed diagnoses (detected > 24 h after injury) after transfer to our hospital. For 47 of the 88 patients (53%), the new diagnoses required a change of management. The Glasgow Coma Scale (GCS) was the only statistically significant risk factor for a new diagnosis upon transfer. CONCLUSIONS: Inter-hospital transfer of severely injured patients increases the risk of a delayed detection of injuries. We found that 35% of all transferred patients with an ISS ≥ 16 have at least new diagnoses, with over half of these diagnoses requiring a change of management. Given these findings, clinicians should maintain a high index of suspicion when receiving a transferred severely injured trauma patient

    Concentration of electric dipole strength below the neutron separation energy in N = 82 nuclei

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    The semi-magic nuclei Ba-138, Ce-140, and Sm-144 have been investigated in photon scattering experiments up to an excitation energy of about 10 MeV. The distribution of the electric dipole strength shows a resonance like structure at energies between 5.5 and 8 MeV exhausting up to 1% of the isovector E1 Energy Weighted Sum Rule.Comment: 10 pages, 3 figure

    In Vivo Measurement of Cerebral Mitochondrial Metabolism Using Broadband Near Infrared Spectroscopy Following Neonatal Stroke

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    Neonatal stroke presents with features of encephalopathy and can result in significant morbidity and mortality. We investigated the cerebral metabolic and haemodynamic changes following neonatal stroke in a term infant at 24 h of life. Changes in oxidation state of cytochrome-c-oxidase (oxCCO) concentration were monitored along with changes in oxy- and deoxy- haemoglobin using a new broadband near-infrared spectroscopy (NIRS) system. Repeated transient changes in cerebral haemodynamics and metabolism were noted over a 3-h study period with decrease in oxyhaemoglobin (HbO2), deoxy haemoglobin (HHb) and oxCCO in both cerebral hemispheres without significant changes in systemic observations. A clear asymmetry was noted in the degree of change between the two cerebral hemispheres. Changes in cerebral oxygenation (measured as HbDiff=HbO2-HHb) and cerebral metabolism (measured as oxCCO) were highly coupled on the injured side of the brain

    Search for the electric dipole excitations to the 3s1/2⊗[21+⊗31−]3s_{1/2} \otimes [2^{+}_{1} \otimes 3^{-}_{1}] multiplet in 117^{117}Sn

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    The odd-mass 117^{117}Sn nucleus was investigated in nuclear resonance fluorescence experiments up to an endpoint energy of the incident photon spectrum of 4.1 MeV at the bremsstrahlung facility of the Stuttgart University. More than 50 mainly hitherto unknown levels were found. From the measurement of the scattering cross sections model independent absolute electric dipole excitation strengths were extracted. The measured angular distributions suggested the spins of 11 excited levels. Quasi-particle phonon model calculations including a complete configuration space were performed for the first time for a heavy odd-mass spherical nucleus. These calculations give a clear insight in the fragmentation and distribution of the E1E1, M1M1, and E2E2 excitation strength in the low energy region. It is proven that the 1−1^{-} component of the two-phonon [21+⊗31−][2^{+}_{1} \otimes 3^{-}_{1}] quintuplet built on top of the 1/2+1/2^{+} ground state is strongly fragmented. The theoretical calculations are consistent with the experimental data.Comment: 10 pages, 5 figure

    State-of-the-art neonatal cerebral ultrasound: technique and reporting

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    In the past three decades, cerebral ultrasound (CUS) has become a trusted technique to study the neonatal brain. It is a relatively cheap, non-invasive, bedside neuroimaging method available in nearly every hospital. Traditionally, CUS was used to detect major abnormalities, such as intraventricular hemorrhage (IVH), periventricular hemorrhagic infarction, post-hemorrhagic ventricular dilatation, and (cystic) periventricular leukomalacia (cPVL). The use of different acoustic windows, such as the mastoid and posterior fontanel, and ongoing technological developments, allows for recognizing other lesion patterns (e.g., cerebellar hemorrhage, perforator stroke, developmental venous anomaly). The CUS technique is still being improved with the use of higher transducer frequencies (7.5-18\u2009MHz), 3D applications, advances in vascular imaging (e.g. ultrafast plane wave imaging), and improved B-mode image processing. Nevertheless, the helpfulness of CUS still highly depends on observer skills, knowledge, and experience. In this special article, we discuss how to perform a dedicated state-of-the-art neonatal CUS, and we provide suggestions for structured reporting and quality assessment
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