384 research outputs found

    ηπ0γγ\eta \to \pi^0 \gamma \gamma decay within unitarized chiral perturbation theory

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    We improve the calculations of the ηπ0γγ\eta \to \pi^0 \gamma \gamma decay within the context of meson chiral lagrangians. We use a chiral unitary approach for the meson-meson interaction, thus generating the a0(980)a_0(980) resonance and fixing the longstanding sign ambiguity on its contribution. This also allows us to calculate the loops with one vector meson exchange, thus removing a former source of uncertainty. In addition we ensure the consistency of the approach with other processes. First, by using vector meson dominance couplings normalized to agree with radiative vector meson decays. And, second, by checking the consistency of the calculations with the related γγπ0η\gamma \gamma \to \pi^0 \eta reaction. We find an ηπ0γγ\eta \to \pi^0 \gamma \gamma decay width of 0.47±0.100.47\pm 0.10 eV, in clear disagreement with published data but in remarkable agreement with the most recent measurement.Comment: 15 pages, 10 figures, published versio

    Reconstruction of Partial Hypopharyngeal Defects following Total Laryngectomy:A Systematic Review and Meta-Analysis

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    Background: Various operative techniques exist to reconstruct partial hypopharyngeal defects following total laryngectomy. The current study aimed to investigate and compare complications and functional results following commonly used reconstructive techniques. Methods: A systematic review and meta-analysis were performed using studies that investigated outcomes after the reconstruction of a partial hypopharyngeal defect. The outcomes of interest were fistulas, strictures, flap failure, swallowing function and postoperative speech. Results: Of the 4035 studies identified, 23 were included in this review. Four common reconstructive techniques were reported, with a total of 794 patients: (1) pectoralis major myocutaneous and (2) myofascial flap, (3) anterolateral thigh free flap and (4) radial forearm free flap. Fistulas occurred significantly more often than pectoralis major myocutaneous flaps (34%, 95% CI 23–47%) compared with other flaps (p &lt; 0.001). No significant differences in the rates of strictures or flap failure were observed. Pectoralis major myofascial flaps were non-inferior to free-flap reconstructions. Insufficient data were available to assess speech results between flap types. Conclusion: Pectoralis myocutaneous flaps should not be the preferred method of reconstruction for most patients, considering their significantly higher rate of fistulas. In contrast, pectoralis major myofascial flaps yield promising results compared to free-flap reconstructions, warranting further investigation.</p

    Reconstruction of Partial Hypopharyngeal Defects following Total Laryngectomy:A Systematic Review and Meta-Analysis

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    Background: Various operative techniques exist to reconstruct partial hypopharyngeal defects following total laryngectomy. The current study aimed to investigate and compare complications and functional results following commonly used reconstructive techniques. Methods: A systematic review and meta-analysis were performed using studies that investigated outcomes after the reconstruction of a partial hypopharyngeal defect. The outcomes of interest were fistulas, strictures, flap failure, swallowing function and postoperative speech. Results: Of the 4035 studies identified, 23 were included in this review. Four common reconstructive techniques were reported, with a total of 794 patients: (1) pectoralis major myocutaneous and (2) myofascial flap, (3) anterolateral thigh free flap and (4) radial forearm free flap. Fistulas occurred significantly more often than pectoralis major myocutaneous flaps (34%, 95% CI 23–47%) compared with other flaps (p &lt; 0.001). No significant differences in the rates of strictures or flap failure were observed. Pectoralis major myofascial flaps were non-inferior to free-flap reconstructions. Insufficient data were available to assess speech results between flap types. Conclusion: Pectoralis myocutaneous flaps should not be the preferred method of reconstruction for most patients, considering their significantly higher rate of fistulas. In contrast, pectoralis major myofascial flaps yield promising results compared to free-flap reconstructions, warranting further investigation.</p

    The Ultrashort Mental Health Screening Tool Is a Valid and Reliable Measure With Added Value to Support Decision-making

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    BACKGROUND: Mental health influences symptoms, outcomes, and decision-making in musculoskeletal healthcare. Implementing measures of mental health in clinical practice can be challenging. An ultrashort screening tool for mental health with a low burden is currently unavailable but could be used as a conversation starter, expectation management tool, or decision support tool.QUESTIONS/PURPOSES: (1) Which items of the Pain Catastrophizing Scale (PCS), Patient Health Questionnaire (PHQ-4), and Brief Illness Perception Questionnaire (B-IPQ) are the most discriminative and yield a high correlation with the total scores of these questionnaires? (2) What is the construct validity and added clinical value (explained variance for pain and hand function) of an ultrashort four-item mental health screening tool? (3) What is the test-retest reliability of the screening tool? (4) What is the response time for the ultrashort screening tool?METHODS: This was a prospective cohort study. Data collection was part of usual care at Xpert Clinics, the Netherlands, but prospective measurements were added to this study. Between September 2017 and January 2022, we included 19,156 patients with hand and wrist conditions. We subdivided these into four samples: a test set to select the screener items (n = 18,034), a validation set to determine whether the selected items were solid (n = 1017), a sample to determine the added clinical value (explained variance for pain and hand function, n = 13,061), and a sample to assess the test-retest reliability (n = 105). Patients were eligible for either sample if they completed all relevant measurements of interest for that particular sample. To create an ultrashort screening tool that is valid, reliable, and has added value, we began by picking the most discriminatory items (that is, the items that were most influential for determining the total score) from the PCS, PHQ-4, and B-IPQ using chi-square automated interaction detection (a machine-learning algorithm). To assess construct validity (how well our screening tool assesses the constructs of interest), we correlated these items with the associated sum score of the full questionnaire in the test and validation sets. We compared the explained variance of linear models for pain and function using the screening tool items or the original sum scores of the PCS, PHQ-4, and B-IPQ to further assess the screening tool's construct validity and added value. We evaluated test-retest reliability by calculating weighted kappas, ICCs, and the standard error of measurement.RESULTS: We identified four items and used these in the screening tool. The screening tool items were highly correlated with the PCS (Pearson coefficient = 0.82; p &lt; 0.001), PHQ-4 (0.87; p &lt; 0.001), and B-IPQ (0.85; p &lt; 0.001) sum scores, indicating high construct validity. The full questionnaires explained only slightly more variance in pain and function (10% to 22%) than the screening tool did (9% to 17%), again indicating high construct validity and much added clinical value of the screening tool. Test-retest reliability was high for the PCS (ICC 0.75, weighted kappa 0.75) and B-IPQ (ICC 0.70 to 0.75, standard error of measurement 1.3 to 1.4) items and moderate for the PHQ-4 item (ICC 0.54, weighted kappa 0.54). The median response time was 43 seconds, against more than 4 minutes for the full questionnaires.CONCLUSION: Our ultrashort, valid, and reliable screening tool for pain catastrophizing, psychologic distress, and illness perception can be used before clinician consultation and may serve as a conversation starter, an expectation management tool, or a decision support tool. The clinical utility of the screening tool is that it can indicate that further testing is warranted, guide a clinician when considering a consultation with a mental health specialist, or support a clinician in choosing between more invasive and less invasive treatments. Future studies could investigate how the tool can be used optimally and whether using the screening tool affects daily clinic decisions.LEVEL OF EVIDENCE: Level II, diagnostic study.</p

    Role of Scalar Meson Resonances in $K_{L}^{0} \rightarrow \pi^{0} \gamma \gamma Decay

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    Corrections to KL0π0γγK_{L}^{0}\rightarrow \pi^{0} \gamma \gamma decay induced by scalar meson exchange are studied within chiral perturbation theory. In spite of bad knowledge of scalar-mesons parameters, the calculated branching ratio can be changed by a few percent.Comment: 18 pages of text, 2 figures (available upon request); preprint IJS-TP-16-94 , TUM-T31-63-94

    Prevalence of post-traumatic neuropathic pain after digital nerve repair and finger amputation

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    Introduction: Post-traumatic neuropathic pain is a major factor affecting the quality of life after finger trauma and is reported with considerable variance in the literature. This can partially be attributed to the different methods of determining neuropathic pain. The Douleur Neuropathique 4 (DN4) has been validated to be a reliable and non-invasive tool to assess the presence of neuropathic pain. This study investigated the prevalence of neuropathic pain after finger amputation or digital nerve repair using the DN4 questionnaire. Methods: Patients with finger amputation or digital nerve repair were identified between 2011 and 2018 at our institution. After a minimal follow-up of 12 months, the short form DN4 (S-DN4) was used to assess neuropathic pain. Results: A total of 120 patients were included: 50 patients with 91 digital amputations and 70 patients with 87 fingers with digital nerve repair. In the amputation group, 32% of the patients had pain, and 18% had neuropathic pain. In the digital nerve repair group, 38% of the patients had pain, and 14% had neuropathic pain. Secondly, of patient-, trauma-, and treatment-specific factors, only the time between trauma and surgery had a significant negative influence on the prevalence of neuropathic pain in patients with digital nerve repair. Conclusion: This study shows that persistent pain and neuropathic pain are common after finger trauma with nerve damage. One of the significant prognostic factors in developing neuropathic pain is treatment delay between trauma and time of digital nerve repair, which is of major clinical relevance for surgical planning of these injuries.</p

    Paternal Diet Defines Offspring Chromatin State and Intergenerational Obesity

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    The global rise in obesity has revitalized a search for genetic and epigenetic factors underlying the disease. We present a Drosophila model of paternal-diet-induced intergenerational metabolic reprogramming (IGMR) and identify genes required for its encoding in offspring. Intriguingly, we find that as little as 2 days of dietary intervention in fathers elicits obesity in offspring. Paternal sugar acts as a physiological suppressor of variegation, desilencing chromatin-state-defined domains in both mature sperm and in offspring embryos. We identify requirements for H3K9/K27me3-dependent reprogramming of metabolic genes in two distinct germline and zygotic windows. Critically, we find evidence that a similar system may regulate obesity susceptibility and phenotype variation in mice and humans. The findings provide insight into the mechanisms underlying intergenerational metabolic reprogramming and carry profound implications for our understanding of phenotypic variation and evolution

    Determination of the Michel Parameters rho, xi, and delta in tau-Lepton Decays with tau --> rho nu Tags

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    Using the ARGUS detector at the e+ee^+ e^- storage ring DORIS II, we have measured the Michel parameters ρ\rho, ξ\xi, and ξδ\xi\delta for τ±l±ννˉ\tau^{\pm}\to l^{\pm} \nu\bar\nu decays in τ\tau-pair events produced at center of mass energies in the region of the Υ\Upsilon resonances. Using τρν\tau^\mp \to \rho^\mp \nu as spin analyzing tags, we find ρe=0.68±0.04±0.08\rho_{e}=0.68\pm 0.04 \pm 0.08, ξe=1.12±0.20±0.09\xi_{e}= 1.12 \pm 0.20 \pm 0.09, ξδe=0.57±0.14±0.07\xi\delta_{e}= 0.57 \pm 0.14 \pm 0.07, ρμ=0.69±0.06±0.08\rho_{\mu}= 0.69 \pm 0.06 \pm 0.08, ξμ=1.25±0.27±0.14\xi_{\mu}= 1.25 \pm 0.27 \pm 0.14 and ξδμ=0.72±0.18±0.10\xi\delta_{\mu}= 0.72 \pm 0.18 \pm 0.10. In addition, we report the combined ARGUS results on ρ\rho, ξ\xi, and ξδ\xi\delta using this work und previous measurements.Comment: 10 pages, well formatted postscript can be found at http://pktw06.phy.tu-dresden.de/iktp/pub/desy97-194.p

    Factors affecting return to work after surgical treatment of trapeziometacarpal joint osteoarthritis

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    This study aimed to identify factors contributing to the timing of return to work after surgical treatment of trapeziometacarpal joint osteoarthritis and to calculate the costs of lost productivity. We included 627 patients with paid employment who underwent trapeziectomy and ligament reconstruction with tendon interposition. Time to return to work was measured through filling online questionnaires and analysed using survival analysis at 6 weeks and 3, 6 and 12 months after the surgery. Patients also filled in the Michigan Hand Outcomes Questionnaire. Costs of lost productivity were calculated using the human capital method. After 1 year, 78% of the patients returned to work. The median time to return to work was 12 weeks. Factors that significantly affected the time to return to work were occupational intensity (light, moderate or heavy physical labour), whether the dominant hand was treated and the Michigan Hand Outcomes Questionnaire work score and hand functi

    Search for CP Violation in the Decay Z -> b (b bar) g

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    About three million hadronic decays of the Z collected by ALEPH in the years 1991-1994 are used to search for anomalous CP violation beyond the Standard Model in the decay Z -> b \bar{b} g. The study is performed by analyzing angular correlations between the two quarks and the gluon in three-jet events and by measuring the differential two-jet rate. No signal of CP violation is found. For the combinations of anomalous CP violating couplings, h^b=h^AbgVbh^VbgAb{\hat{h}}_b = {\hat{h}}_{Ab}g_{Vb}-{\hat{h}}_{Vb}g_{Ab} and hb=h^Vb2+h^Ab2h^{\ast}_b = \sqrt{\hat{h}_{Vb}^{2}+\hat{h}_{Ab}^{2}}, limits of \hat{h}_b < 0.59and and h^{\ast}_{b} < 3.02$ are given at 95\% CL.Comment: 8 pages, 1 postscript figure, uses here.sty, epsfig.st
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