246 research outputs found

    Helicity asymmetries in neutrino-nucleus interactions

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    We investigate the helicity properties of the ejectile in quasi-elastic neutrino-induced nucleon-knockout reactions and consider the 12C target as a test case. A formalism based on a relativistic mean-field model is adopted. The influence of final-state interactions is evaluated within a relativistic multiple-scattering Glauber approximation (RMSGA) model. Our calculations reveal that the helicity asymmetries A_l in A(\overline{\nu},\overline{\nu}'N) processes are extremely sensitive to strange-quark contributions to the weak vector form-factors. Thereby, nuclear corrections, such as final-state interactions and off-shell ambiguities in the electroweak current operators, are observed to be of marginal importance. This facilitates extracting strange-quark information from the helicity asymmetry A_l.Comment: 14 pages, 6 figures, 1 table submitted to PL

    Relativistic models for quasi-elastic neutrino scattering

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    We present quasi-elastic neutrino-nucleus cross sections in the energy range from 150 MeV up to 5 GeV for the target nuclei 12C and 56Fe. A relativistic description of the nuclear dynamics and the neutrino-nucleus coupling is adopted. For the treatment of final-state interactions (FSI) we rely on two frameworks succesfully applied to exclusive electron-nucleus scattering: a relativistic optical potential and a relativistic multiple-scattering Glauber approximation. At lower energies, the optical-potential approach is considered to be the optimum choice, whereas at high energies a Glauber approach is more natural. Comparing the results of both calculations, it is found that the Glauber approach yields valid results down to the remarkably small nucleon kinetic energies of 200 MeV. We argue that the nuclear transparencies extracted from A(e,e'p) measurements can be used to obtain realistic estimates of the effect of FSI mechanisms on quasi-elastic neutrino-nucleus cross sections. We present two independent relativistic plane-wave impulse approximation (RPWIA) calculations of quasi-elastic neutrino-nucleus cross sections. They agree at the percent level, showing the reliability of the numerical techniques adopted and providing benchmark RPWIA results.Comment: revised version,28 pages, 7 figures, accepted in Phys.Rev.

    PREPARATION OF PLANT MUCILAGE CLARIFICANTS AND THEIR EFFECT ON JAGGERY PROCESSING OF SUGARCANE VARIETY Co 86032

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    Objective: The aim of the study was to prepare jaggery from sugarcane variety Co86032 using plants mucilage as clarificants and to determine the effect of plant mucilage on jaggery processing.Methods: Production of jaggery using five plant clarificants namely Aloe vera, Flax seeds, Fenugreek, Purslane and Malabar spinach at three different concentrations i.e., 0.1%, 0.2% and 0.4% of raw sugarcane juice and the jaggery prepared without any clarificants serves as control. During production, the processing parameters such as quantity of scum removed, total time taken for processing and jaggery yield was determined.Results: It was found that the jaggery prepared using plant mucilage at concentration of 0.4% found superior when compared to 0.2%, 0.1% and control respectively. Aloe vera at 0.4% removed maximum scum (4.07%), taken minimum processing time (72.33 min) and recorded maximum jaggery yield (10.92 kg). The efficacy of Aloe vera as mucilage clarificants in jaggery production was followed by fenugreek, flax seeds, purslane and Malabar spinach in the order respectively.Conclusion: The application of plants mucilage as clarificants in the jaggery production removed significant level of scum, reduced processing time and improved yield of jaggery. Therefore the selected plant mucilages can be used as clarificants in the jaggery production and can be considered as potential alternative to chemical clarificants.Â

    Inter- and Intra-rater Reliability of A Grading System for Congenital Diaphragmatic Hernia Defect Size

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    Background The Congenital Diaphragmatic Hernia Study Group (CDHSG) registry is a multi-institutional tool to track outcomes of patients with CDH. The CDHSG asks surgeons to categorize diaphragmatic defect sizes as type A-D based on published guidelines. The reported size of the defect has been correlated with patient outcomes, but the reliability of this system has never been studied. Our goal was to evaluate the inter- and intra-rater reliability of the CDHSG grading system. Materials and methods Forty-six operative notes from CDH patients that underwent surgical repair at a single institution were collected and cropped to include only the information necessary to grade the hernia defect based on the CDHSG guidelines. The defects were graded by nine pediatric surgeons on two separate occasions (18 wk apart). Inter-rater reliability was calculated using a Cohen's kappa (κ). Intra-rater reliability was calculated using an intraclass correlation coefficient. Results Inter-rater reliability was minimal to weak (κ round1 = 0.395, κ round2 = 0.424). Agreement ranged from 19.57% (κ = −0.0745) to 82.61% (κ = 0.7543). Inter-rater agreement was similar despite operative findings and outcomes: survival yes/no (κ = 0.3690, κ = 0.3518), need for ECMO yes/no (κ = 0.3323, κ = 0.3362), patch repair yes/no (κ = 0.2050, κ = 0.1916), and liver up/down (κ = 0.2941, κ = 0.4404). Intra-rater reliability was good to excellent (intraclass correlation coefficient = 0.88, 95% CI [0.83-0.92]). Agreement with oneself ranged from 71.74% to 93.48%. Conclusions The demonstrated weak inter-rater reliability of the current CDHSG grading system shows the need for improvement in how the grading system is applied by surgeons when reporting CDH defect size

    The underlying challenges that arise when analysing short-chain chlorinated paraffins in environmental matrices

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    As short-chain chlorinated paraffins (SCCPs) are listed on several monitoring programs, validated methods are essential. However, their complexity and the lack of commercially available certified reference materials (RMs) hinder a proper validation of methods. Instead, one method is usually ‘validated’ by evaluating performances and results of spiked materials with that of one other method, which could easily lead to unreliable results. This study evaluated four analytical methods with different principles (i.e. comprehensive two dimensional GC coupled to a micro electron capture detector, developed for this study, chloride enhanced atmospheric pressure chemical ionization triple quadrupole time of flight MS (APCI-QToF-HRMS), GC coupled to an electron capture negative ion low resolution MS (GC–ECNI–LRMS) and carbon skeleton GC–MS), investigated the comparability in SCCP determination in spiked and naturally contaminated samples and determined SCCP amounts in candidate RMs for possible certification. The results cast doubt on the use of the most commonly applied method (i.e. GC–ECNI–LRMS), as well as using spiked materials for method validation. The APCI-QToF-HRMS method was found most promising as it achieves the required MS resolution (>21,000), is relatively fast and can detect also other CPs. The suitable identified SCCP levels in the candidate RMs and the agreement in results between the methods bring the first certification of a RM for SCCPs within reach

    Attentional selectivity, automaticity, and self-efficacy predict simulator-acquired skill transfer to the clinical environment

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    Introduction Several studies demonstrated that simulator-acquired skill transfer to the operating room is incomplete. Our objective was to identify trainee characteristics that predict the transfer of simulator-acquired skill to the operating room. Methods Trainees completed baseline assessments including intracorporeal suturing (IS) performance, attentional selectivity, self-reported use of mental skills, and self-reported prior clinical and simulated laparoscopic experience and confidence. Residents then followed proficiency-based laparoscopic skills training, and their skill transfer was assessed on a live-anesthetized porcine model. Predictive characteristics for transfer test performance were assessed using multiple linear regression. Results Thirty-eight residents completed the study. Automaticity, attentional selectivity, resident perceived ability with laparoscopy and simulators, and post-training IS performance were predictive of IS performance during the transfer test. Conclusions Promoting automaticity, self-efficacy, and attention selectivity may help improve the transfer of simulator-acquired skill. Mental skills training and training to automaticity may therefore be valuable interventions to achieve this goal

    Increased Trauma Activation Is Not Equally Beneficial For All Elderly Trauma Patients

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    Background Physiologic changes in the elderly lead to higher morbidity and mortality after injury. Increasing level of trauma activation has been proposed to improve geriatric outcomes; but, the increased cost to the patient and stress to the hospital system are significant downsides. The purpose of this study was to identify the age at which an increase in activation status is beneficial. Methods A retrospective review of trauma patients ≥ 70 years old from October 1, 2011, to October 1, 2016 was performed. On October 1, 2013, a policy change increased the activation criteria to the highest level for patients ≥ 70 years of age with a significant mechanism of injury. Patients who presented prior to (PRE) were compared to those after the change (POST). Data collected included age, injury severity score (ISS), length of stay (LOS), complications and mortality. Primary outcome was mortality and secondary outcome was LOS. Multivariable regressions controlled for age, ISS, injury mechanism, and number of complications. Results 4341 patients met inclusion criteria, 1919 in PRE and 2422 in POST. Mean age was 80.4 and 81 years in PRE and POST groups respectively (p=0.0155). Mean ISS values were 11.6 and 12.4 (p<0.0001) for the PRE and POST groups. POST had more level 1 activations (696 vs. 220, p<0.0001). After controlling for age, ISS, mechanism of injury, and number of complications, mortality was significantly reduced in the POST group ≥ age 77 years (OR 0.53, 95% CI: 0.3 - 0.87), (Figure 1). Hospital LOS was significantly reduced in the POST group ≥ age 78 (regression coefficient -0.55, 95% CI: -1.09, -0.01) (Figure 2). Conclusions This study suggests geriatric trauma patients ≥ 77 years benefit from the highest level of trauma activation with shorter LOS and lower mortality. A focused approach to increasing activation level for elderly patients may decrease patient cost. Level of Evidence Level III Type of Study Economic/Decisio

    Atypical Bacterial Pathogens and Small-Vessel Leukocytoclastic Vasculitis of the Skin in Children: Systematic Literature Review.

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    Leukocytoclastic small-vessel vasculitis of the skin (with or without systemic involvement) is often preceded by infections such as common cold, tonsillopharyngitis, or otitis media. Our purpose was to document pediatric (≤18 years) cases preceded by a symptomatic disease caused by an atypical bacterial pathogen. We performed a literature search following the Preferred Reporting of Systematic Reviews and Meta-Analyses guidelines. We retained 19 reports including 22 cases (13 females and 9 males, 1.0 to 17, median 6.3 years of age) associated with a Mycoplasma pneumoniae infection. We did not find any case linked to Chlamydophila pneumoniae, Chlamydophila psittaci, Coxiella burnetii, Francisella tularensis, or Legionella pneumophila. Patients with a systemic vasculitis (N = 14) and with a skin-limited (N = 8) vasculitis did not significantly differ with respect to gender and age. The time to recovery was ≤12 weeks in all patients with this information. In conclusion, a cutaneous small-vessel vasculitis with or without systemic involvement may occur in childhood after an infection caused by the atypical bacterial pathogen Mycoplasma pneumoniae. The clinical picture and the course of cases preceded by recognized triggers and by this atypical pathogen are indistinguishable

    Which laboratory technique is used for the blood sodium analysis in clinical research? A systematic review.

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    Circulating sodium is analyzed by flame spectrometry and indirect or direct potentiometry. The differences between estimates returned by the three techniques are often relevant. It is unknown whether peer-reviewed international publications focusing on this parameter provide information about the technique. Objectives of the study were to ascertain if information about the employed technique is provided. A search in the National Library of Medicine for articles whose title contains "hyponatr[a]emia" was performed. We restricted the search to clinical reports including 10 or more humans published in the 2013-2015 and 2017-2019 periods. Authors of papers not reporting the technique were contacted to obtain this information. The study design and journal quartile ranking of each article were also evaluated. For the final analysis, we included 361 articles (2013-2015, n=169; 2017-2019, n=192). Information about the laboratory technique was given in 61(17%) articles. Thanks to our inquiry, we collected this information for 116(32%) further reports. Indirect potentiometry was the most frequently used technique, followed by direct potentiometry. Spectrometry was used in a small minority of studies. Study design, journal ranking and study period did not modulate the mentioned frequency. Most articles focusing on hyponatremia do not provide information on the laboratory technique. This parameter is nowadays analyzed by indirect or, less frequently, direct potentiometry. The figures are similar for high and low impact factor journals and for the 2013-2015 and the 2017-2019 periods. Many authors, reviewers and editors likely assume that the results of this parameter are not influenced by the technique
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