69 research outputs found

    Exact Spin and Pseudo-Spin Symmetric Solutions of the Dirac-Kratzer Problem with a tensor potential via Laplace Transform Approach

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    Exact bound state solutions of the Dirac equation for the Kratzer potential in the presence of a tensor potential are studied by using the Laplace transform approach for the cases of spin- and pseudo-spin symmetry. The energy spectra is obtained in the closed form for the relativistic as well as non-relativistic cases including the Coulomb potential. It is seen that our analytical results are in agrement with the ones given in literature. The numerical results are also given in a table for different parameter values.Comment: 8 page

    General energy bounds for systems of bosons with soft cores

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    We study a bound system of N identical bosons interacting by model pair potentials of the form V(r) = A sgn(p)r^p + B/r^2, A > 0, B >= 0. By using a variational trial function and the `equivalent 2-body method', we find explicit upper and lower bound formulas for the N-particle ground-state energy in arbitrary spatial dimensions d > 2 for the two cases p = 2 and p = -1. It is demonstrated that the upper bound can be systematically improved with the aid of a special large-N limit in collective field theory

    Middle East - North Africa and the millennium development goals : implications for German development cooperation

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              Closed-loop controlled combustion is a promising technique to improve the overall performance of internal combustion engines and Diesel engines in particular. In order for this technique to be implemented some form of feedback from the combustion process is required. The feedback signal is processed and from it combustionrelated parameters are computed. These parameters are then fed to a control process which drives a series of outputs (e.g. injection timing in Diesel engines) to control their values. This paper’s focus lies on the processing and computation that is needed on the feedback signal before this is ready to be fed to the control process as well as on the electronics necessary to support it. A number of feedback alternatives are briefly discussed and for one of them, the in-cylinder pressure sensor, the CA50 (crank angle in which the integrated heat release curve reaches its 50% value) and the IMEP (Indicated Mean Effective Pressure) are identified as two potential control variables. The hardware architecture of a system capable of calculating both of them on-line is proposed and necessary feasibility size and speed considerations are made by implementing critical blocks in VHDL targeting a flash-based Actel ProASIC3 automotive-grade FPGA

    Experimental study of spin-exchange effects in elastic and ionizing collisions of polarized electrons with polarized hydrogen atoms

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    Rechtscharakter und Funktionen der Bretton-Woods-Institutionen: (Weltbankgruppe und IWF) — eine kleine Institutionenkunde

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    Use of ALK-tyrosine kinase inhibitors (ALK TKI) in clinical practice, overall survival, and treatment duration - a Swedish nationwide retrospective study

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    Background The real-world treatment and outcomes of patients with anaplastic lymphoma kinase positive (ALK+) advanced non-small cell lung cancer treated with ALK Tyrosine Kinase Inhibitor (TKI) drugs in Sweden is not well described. Material and methods A retrospective population-based cohort study was conducted using Swedish national registers. All patients with a filled prescription for an ALK TKI between January 2012 and October 2020 were included. The sequencing of ALK TKI and duration of treatment (DOT) were described, and overall survival (OS) was estimated using the Kaplan-Meier method. Patients were stratified based on treatment with frontline chemotherapy, presence of CNS metastases prior to the first ALK TKI, and generation of ALK TKI agent. Results Among the total of 579 patients, 549 (95%) underwent a therapy sequence in line with current clinical practice with 204 (37%) patients receiving frontline chemotherapy. Single-line ALK TKI was given to 366 patients (crizotinib: 211; alectinib: 146; ceritinib: 9), whereas 128 patients received two different ALK TKI (frontline crizotinib: 100, alectinib: 24, ceritinib: 4); 40 patients received three lines and 15 patients four ALK TKI lines or more. With frontline chemotherapy, the mean (standard deviation) DOT was 1.07 (1.25) years for the entire TKI therapy sequence compared to 1.23 (1.28) years with frontline ALK TKI. The median (95% confidence interval) OS was 1.83 (1.48-2.13) years for the entire cohort, 1.44 (0.89-1.98) years for patients given frontline chemotherapy, and 2.02 (1.60-2.58) years for patients given frontline ALK TKI. Conclusion This study provides a unique overview of the patient population treated with ALK TKI in Sweden and reveals the treatment patterns applied in real clinical practice. More research is needed when longer follow-up data are available for later-generation ALK TKI, to fully understand ALK TKI sequencing and its effect on patient survival in a real-world setting.Funding Agencies|Pfizer</p
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