355 research outputs found

    Lifetime measurement of excited low-spin states via the (p,p′γ(p,p^{\prime}\gamma) reaction

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    In this article a method for lifetime measurements in the sub-picosecond regime via the Doppler-shift attenuation method (DSAM) following the inelastic proton scattering reaction is presented. In a pioneering experiment we extracted the lifetimes of 30 excited low-spin states of 96^{96}Ru, taking advantage of the coincident detection of scattered protons and de-exciting γ\gamma-rays as well as the large number of particle and γ\gamma-ray detectors provided by the SONIC@HORUS setup at the University of Cologne. The large amount of new experimental data shows that this technique is suited for the measurement of lifetimes of excited low-spin states, especially for isotopes with a low isotopic abundance, where (n,n′γ(n,n^{\prime}\gamma) or - in case of investigating dipole excitations - (γ,γ′\gamma,\gamma^{\prime}) experiments are not feasible due to the lack of sufficient isotopically enriched target material

    Towards a benchmark of abdominal CT use during duty shifts:15-year sample from the Netherlands

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    Purpose: To investigate temporal changes in the utilization and patient impact of abdominal CT during duty shifts in the past 15 years. Methods: This study included a random sample of 1761 abdominal CT scans that were made during evening and night duty shifts in a tertiary care center between 2005 and 2019. Results: The number of CT scans significantly increased (almost threefold) between 2005 and 2019 (Mann–Kendall tau of 0.829, P < 0.001). The proportion of negative CT scans (i.e., the absence of findings related to the reason that the CT scan was made and no disease deterioration or other new and clinically relevant findings compared to a previous imaging examination when available) was 40.0% (700/1749) in the entire 15-year study frame and did not significantly change over time (Mann–Kendall tau of − 0.219, P = 0.276). The overall frequency of same-day hospital discharge after negative CT was 20.6% (150/729) in the past 15 years and showed a significant increase over time (Mann–Kendall tau of 0.505, P = 0.010). The overall proportion of CT scans with incidental findings was 3.4% (60/1761) and remained statistically stable over the past 15 years (Mann–Kendall tau of − 0.057, P = 0.804). Conclusion: Over the past 15 years, the number of CT scans and the frequency of same-day hospital discharge after negative CT have increased, while the proportions of negative CT scans and incidental findings have remained stable in our tertiary care center. The data from this study can be used for interinstitutional benchmarking to define, monitor, and improve the appropriateness of imaging utilization

    The decay of quadrupole-octupole 1−1^- states in 40^{40}Ca and 140^{140}Ce

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    Background: Two-phonon excitations originating from the coupling of two collective one-phonon states are of great interest in nuclear structure physics. One possibility to generate low-lying E1E1 excitations is the coupling of quadrupole and octupole phonons. Purpose: In this work, the γ\gamma-decay behavior of candidates for the (21+⊗31−)1−(2_1^+\otimes 3_1^-)_{1^-} state in the doubly-magic nucleus 40^{40}Ca and in the heavier and semi-magic nucleus 140^{140}Ce is investigated. Methods: (γ⃗,γ′)(\vec{\gamma},\gamma') experiments have been carried out at the High Intensity γ\gamma-ray Source (HIγ{\gamma}S) facility in combination with the high-efficiency γ\gamma-ray spectroscopy setup γ3\gamma^3 consisting of HPGe and LaBr3_3 detectors. The setup enables the acquisition of γ\gamma-γ\gamma coincidence data and, hence, the detection of direct decay paths. Results: In addition to the known ground-state decays, for 40^{40}Ca the decay into the 31−3^-_1 state was observed, while for 140^{140}Ce the direct decays into the 21+2^+_1 and the 02+0^+_2 state were detected. The experimentally deduced transition strengths and excitation energies are compared to theoretical calculations in the framework of EDF theory plus QPM approach and systematically analyzed for N=82N=82 isotones. In addition, negative parities for two J=1J=1 states in 44^{44}Ca were deduced simultaneously. Conclusions: The experimental findings together with the theoretical calculations support the two-phonon character of the 11−1^-_1 excitation in the light-to-medium-mass nucleus 40^{40}Ca as well as in the stable even-even N=82N=82 nuclei.Comment: 11 pages, 6 figures, as accepted in Phys. Rev.

    Breast Milk from Tanzanian Women has Divergent Effects on Cell-Free and Cell-Associated HIV-1 Infection in Vitro.

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    Transmission of HIV-1 during breastfeeding is a significant source of new pediatric infections in sub-Saharan Africa. Breast milk from HIV-positive mothers contains both cell-free and cell-associated virus; however, the impact of breast milk on HIV-1 infectivity remains poorly understood. In the present study, breast milk was collected from HIV-positive and HIV-negative Tanzanian women attending antenatal clinics in Dar es Salaam. Milk was analyzed for activity in vitro against both cell-free and cell-associated HIV-1. Potent inhibition of cell-free R5 and X4 HIV-1 occurred in the presence of milk from all donors regardless of HIV-1 serostatus. Inhibition of cell-free HIV-1 infection positively correlated with milk levels of sialyl-Lewis(X) from HIV-positive donors. In contrast, milk from 8 of 16 subjects enhanced infection with cell-associated HIV-1 regardless of donor serostatus. Milk from two of these subjects contained high levels of multiple pro-inflammatory cytokines including TNFα, IL-1β, IL-6, IL-8, MIP-1α, MIP-1β, MCP-1 and IP-10, and enhanced cell-associated HIV-1 infection at dilutions as high as 1∶500. These findings indicate that breast milk contains innate factors with divergent activity against cell-free and cell-associated HIV-1 in vitro. Enhancement of cell-associated HIV-1 infection by breast milk may be associated with inflammatory conditions in the mother and may contribute to infant infection during breastfeeding

    Isospin properties of electric dipole excitations in 48Ca

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    Two different experimental approaches were combined to study the electric dipole strength in the doubly-magic nucleus 48Ca below the neutron threshold. Real-photon scattering experiments using bremsstrahlung up to 9.9 MeV and nearly mono-energetic linearly polarized photons with energies between 6.6 and 9.51 MeV provided strength distribution and parities, and an (\alpha,\alpha'\gamma) experiment at E_{\alpha}=136 MeV gave cross sections for an isoscalar probe. The unexpected difference observed in the dipole response is compared to calculations using the first-order random-phase approximation and points to an energy-dependent isospin character. A strong isoscalar state at 7.6 MeV was identified for the first time supporting a recent theoretical prediction.Comment: 6 pages, 5 figures, as accepted in Phys. Lett.

    High-Tech Augmentative and Alternative Communication for Individuals with IDD and Complex Communication Needs: A Meta-Analysis (Variable Codes)

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    The attachment includes the operational definitions of the variable codes for the following article: The use of mobile technology is ubiquitous and is rapidly increasing in novel use. The use of mobile apps as augmentative and alternative communication (AAC) is rapidly expanding, both in the community and in the research literature. This article reports the social-communication outcome results of a meta-analysis of single-case experimental research on the use of high-tech AAC with individuals with intellectual and developmental disabilities, including autism spectrum disorder. Following inclusion determination, including excluding studies with poor design quality, raw data from 24 publications were extracted and included 89 A-B phase contrasts. Tau-U nonparametric, non-overlap effect size was used to aggregate the results across all studies for an omnibus and moderator analyses. Kendall’s S was calculated for confidence intervals, p-values, and standard error. The omnibus analysis indicated overall low to moderate positive effects on social-communication outcomes for high-tech AAC with people with IDD.The contents of this manuscript were developed under the Preparation of Leaders in Autism Across the Lifespan grant awarded by the U.S. Department of Education, Office of Special Education Programs (Grant No. H325D110046)

    High-Tech Augmentative and Alternative Communication for Individuals with IDD and Complex Communication Needs: A Meta-Analysis (Search Terms)

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    Search Terms used in this manuscriptSearch Terms attached for the following paper: The use of mobile technology is ubiquitous and is rapidly increasing in novel use. The use of mobile apps as augmentative and alternative communication (AAC) is rapidly expanding, both in the community and in the research literature. This article reports the social-communication outcome results of a meta-analysis of single-case experimental research on the use of high-tech AAC with individuals with intellectual and developmental disabilities, including autism spectrum disorder. Following inclusion determination, including excluding studies with poor design quality, raw data from 24 publications were extracted and included 89 A-B phase contrasts. Tau-U nonparametric, non-overlap effect size was used to aggregate the results across all studies for an omnibus and moderator analyses. Kendall’s S was calculated for confidence intervals, p-values, and standard error. The omnibus analysis indicated overall low to moderate positive effects on social-communication outcomes for high-tech AAC with people with IDD.The contents of this manuscript were developed under the Preparation of Leaders in Autism Across the Lifespan grant awarded by the U.S. Department of Education, Office of Special Education Programs (Grant No. H325D110046)

    In Mice, Tuberculosis Progression Is Associated with Intensive Inflammatory Response and the Accumulation of Gr-1dim Cells in the Lungs

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    Infection with Mycobacterium tuberculosis (Mtb) results in different clinical outcomes ranging from asymptomatic containment to rapidly progressing tuberculosis (TB). The mechanisms controlling TB progression in immunologically-competent hosts remain unclear.To address these mechanisms, we analyzed TB progression in a panel of genetically heterogeneous (A/SnxI/St) F2 mice, originating from TB-highly-susceptible I/St and more resistant A/Sn mice. In F2 mice the rates of TB progression differed. In mice that did not reach terminal stage of infection, TB progression did not correlate with lung Mtb loads. Nor was TB progression correlated with lung expression of factors involved in antibacterial immunity, such as iNOS, IFN-gamma, or IL-12p40. The major characteristics of progressing TB was high lung expression of the inflammation-related factors IL-1beta, IL-6, IL-11 (p<0.0003); CCL3, CCL4, CXCL2 (p<0.002); MMP-8 (p<0.0001). The major predictors of TB progression were high expressions of IL-1beta and IL-11. TNF-alpha had both protective and harmful effects. Factors associated with TB progression were expressed mainly by macrophages (F4-80(+) cells) and granulocytes (Gr-1(hi)/Ly-6G(hi) cells). Macrophages and granulocytes from I/St and A/Sn parental strains exhibited intrinsic differences in the expression of inflammatory factors, suggesting that genetically determined peculiarities of phagocytes transcriptional response could account for the peculiarities of gene expression in the infected lungs. Another characteristic feature of progressing TB was the accumulation in the infected lungs of Gr-1(dim) cells that could contribute to TB progression.In a population of immunocompetent hosts, the outcome of TB depends on quantitatively- and genetically-controlled differences in the intensity of inflammatory responses, rather than being a direct consequence of mycobacterial colonization. Local accumulation of Gr-1(dim) cells is a newly identified feature of progressing TB. High expression of IL-1beta and IL-11 are potential risk factors for TB progression and possible targets for TB immunomodulation

    False positives in PIRADS (V2) 3, 4, and 5 lesions:relationship with reader experience and zonal location

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    PURPOSE: To investigate the effect of reader experience and zonal location on the occurrence of false positives (FPs) in PIRADS (V2) 3, 4, and 5 lesions on multiparametric (MP)-MRI of the prostate. MATERIALS AND METHODS: This retrospective study included 139 patients who had consecutively undergone an MP-MRI of the prostate in combination with a transrectal ultrasound MRI fusion-guided biopsy between 2014 and 2017. MRI exams were prospectively read by a group of inexperienced radiologists (cohort 1; 54 patients) and an experienced radiologist (cohort 2; 85 patients). Multivariable logistic regression analysis was performed to determine the association of experience of the radiologist and zonal location with a FP reading. FP rates were compared between readings by inexperienced and experienced radiologists according to zonal location, using Chi-square (χ2) tests. RESULTS: A total of 168 lesions in 139 patients were detected. Median patient age was 68 years (Interquartile range (IQR) 62.5-73), and median PSA was 10.9 ng/mL (IQR 7.6-15.9) for the entire patient cohort. According to multivariable logistic regression, inexperience of the radiologist was significantly (P = 0.044, odds ratio 1.927, 95% confidence interval [CI] 1.017-3.651) and independently associated with a FP reading, while zonal location was not (P = 0.202, odds ratio 1.444, 95% CI 0.820-2.539). In the transition zone (TZ), the FP rate of the inexperienced radiologists 59% (17/29) was significantly higher (χ2P = 0.033) than that of the experienced radiologist 33% (13/40). CONCLUSION: Inexperience of the radiologist is significantly and independently associated with a FP reading, while zonal location is not. Inexperienced radiologists have a significantly higher FP rate in the TZ

    Mixed-symmetry octupole and hexadecapole excitations in N=52 isotones

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    In addition to the well-established quadrupole mixed-symmetry states, octupole and hexadecapole excitations with mixed-symmetry character have been recently proposed for the N = 52 isotones 92Zr and 94Mo. We performed two inelastic proton-scattering experiments to study this kind of excitations in the heaviest stable N = 52 isotone 96Ru. From the combined experimental data of both experiments absolute transition strengths were extracted
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