521 research outputs found

    Study of the doubly charmed tetraquark T+cc

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    Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an exotic narrow state in the D0D0π+ mass spectrum just below the D*+D0 mass threshold produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The state is consistent with the ground isoscalar T+cc tetraquark with a quark content of ccu⎯⎯⎯d⎯⎯⎯ and spin-parity quantum numbers JP = 1+. Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D*+ mesons is consistent with the observed D0π+ mass distribution. To analyse the mass of the resonance and its coupling to the D*D system, a dedicated model is developed under the assumption of an isoscalar axial-vector T+cc state decaying to the D*D channel. Using this model, resonance parameters including the pole position, scattering length, effective range and compositeness are determined to reveal important information about the nature of the T+cc state. In addition, an unexpected dependence of the production rate on track multiplicity is observed

    Supplement 1. Source code for simulations.

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    File List scanning.tar.gz -- Compressed archive with the C source code files README -- Instructions for compilation and use Description This program 'xscanning' performs a given number of numerical integrations for the multispecies Droop model. The simulation parameters are described in the 'header.h' file, and can be modified there. These parameters include: BAND : the dominant band of the R-star matrix MAX : the number of species(=resources) RRANGE: the range from which the R-star values are chosen FRANGE: the range from which the F-hat values are chosen RUNS : the number of runs TIME : the number of days per run The program takes care of the generation of V, K, and Q matrices according to the rules described in Appendix A. The source code is written in ANSI-C and makes use of the GNU Scientific Library for numerical integration of ordinary differential equations http://www.gnu.org/software/gsl/. More details in the README file

    Factor 11 single-nucleotide variants in women with heavy menstrual bleeding

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    In a previous study it was shown that lower factor XI (FXI) levels in women with heavy menstrual bleeding (HMB). Our aim was to determine the single-nucleotide variants (SNVs) in the F11 gene in women with HMB. In addition, an extensive literature search was performed to determine the clinical significance of each SNV. Patients referred for HMB (PBAC-score >100) were included. With direct sequencing analysis of all 15 exons and flanking introns of the F11 gene, 29 different non-structural SNVs were detected in 49 patients with HMB. Interestingly, most of these SNVs have previously been associated with venous thrombosis instead of bleeding. These findings have not helped to elucidate the molecular basis of HMB. They also question the specificity of previously reported F11 variations in patients with thrombosis. More studies are needed to explain the lower FXI levels seen in patients with HMB.IMPACT STATEMENTWomen with mild deficiencies of factor XI (FXI) (In light of these findings, we performed F11 gene analysis to determine the single-nucleotide variants (SNVs) in women with HMB and performed an extensive literature search to determine the clinical significance of each SNV. By direct sequencing analysis of the F11 gene we found 29 different non-structural SNVs in 49 women with heavy menstrual bleeding. Remarkably, a number of these SNVs have previously been implicated in thrombosis.These findings have not helped to elucidate the molecular basis of lower FXI levels in HMB. They also question the specificity of previously reported F11 variations in patients with thrombosis. More studies are needed to explain the lower FXI levels seen in patients with HMB. Women with mild deficiencies of factor XI (FXI) ( In light of these findings, we performed F11 gene analysis to determine the single-nucleotide variants (SNVs) in women with HMB and performed an extensive literature search to determine the clinical significance of each SNV. By direct sequencing analysis of the F11 gene we found 29 different non-structural SNVs in 49 women with heavy menstrual bleeding. Remarkably, a number of these SNVs have previously been implicated in thrombosis. These findings have not helped to elucidate the molecular basis of lower FXI levels in HMB. They also question the specificity of previously reported F11 variations in patients with thrombosis. More studies are needed to explain the lower FXI levels seen in patients with HMB

    Supplementary Material for: Criteria for Continuous Kidney Replacement Therapy Cessation in ICU Patients

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    Introduction: In intensive care unit (ICU) patients with acute kidney injury, specific recommendations to guide the decision to cease continuous kidney replacement therapy (CKRT) are lacking. Methods: We performed a survey to identify criteria currently used to cease CKRT in real-life clinical practice in the Netherlands. We used an online questionnaire with multiple choice questions designed with web-based software from SurveyMonkey. Results: We received 169 completed questionnaires from intensivists (n = 126) and nephrologists (n = 43). Essential determinants for the cessation of CKRT were a spontaneously increasing diuresis (indicated by 92% of the respondents), absence of fluid overload (indicated by 88% of the respondents), and improvement in creatinine clearance (indicated by 61% of the respondents; intensivists 56%; nephrologists 77%, p = 0.03). Most often mentioned cut-off values used for increase in diuresis were 0.25 and 0.5 mL/kg/h (35% and 33%, respectively). Actual CKRT cessation was often postponed until the filter clots or until circuit disconnection is needed because of patient transport for diagnostic or intervention procedures (indicated by 58% of the respondents). Expected discharge from the ICU was the most frequently reported determinant to switch from CKRT to hemodialysis (indicated by 67% of the respondents). Conclusions: CKRT cessation in clinical practice is mostly based on spontaneously increasing diuresis, absence of fluid overload, and improvement in creatinine clearance and is often delayed until filter clotting or disconnection of the circuit because of logistic reasons
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