46 research outputs found

    Obesity, comorbidities, and treatment selection in Black and White women with early breast cancer

    Get PDF
    Background: This study investigates obesity and comorbidity in Black and White women with early breast cancer (stages I-III) and their potential impact on treatment decisions for patients with hormone receptor–positive (HR+)/human epidermal growth factor receptor 2–negative (HER2–) tumors. Methods: In this retrospective chart review, comparisons of frequencies for Black and White patients were calculated with the Fisher exact test. Log binomial regression was used to estimate prevalence ratios (PRs) with 95% confidence intervals for total and individual comorbidities, and multivariable modeling was used to estimate PRs adjusted for age and body mass index (BMI). Results: In a sample of 548 patients, 26% were Black, and 74% were White. Sixty-two percent of Black patients and 32% of White patients were obese (BMI ≄ 30 kg/m2; P <.0001). Seventy-five percent of Black patients and 87% of White patients had HR+ tumors (P =.001). Significant intergroup differences were seen for 2 or more total comorbidities (62% of Blacks vs 47% of Whites; P =.001), 2 or more obesity-related comorbidities (33% vs 10%; P <.0001), hypertension (60% vs 32%; P <.0001), diabetes mellitus (23% vs 6%; P <;.0001), hypercholesterolemia or hyperlipidemia (28% vs 18%; P =.02), and hypothyroidism (4% vs 11%; P =.012). In women with HR+/HER2– tumors, there were no intergroup differences in treatment decisions regarding the type of surgery, chemotherapy regimen, radiation, or endocrine treatment despite significant differences in the prevalence of obesity and comorbidities. Conclusions: This study documents significant disparities between Black and White women with early breast cancer with regard to high rates of obesity, overall comorbidities, and obesity-related comorbidities, and it highlights the prevalence of competing risks that may complicate outcomes in breast cancer

    Patient-reported treatment toxicity and adverse events in Black and White women receiving chemotherapy for early breast cancer

    Get PDF
    Purpose: It is not known whether chemotherapy-related symptom experiences differ between Black and White women with early breast cancer (Stage I–III) receiving current chemotherapy regimens and, in turn, influences dose delay, dose reduction, early treatment discontinuation, or hospitalization. Methods: Patients self-reported their race and provided symptom reports for 17 major side effects throughout chemotherapy. Toxicity and adverse events were analyzed separately for anthracycline and non-anthracycline regimens. Fisher’s exact tests and two-sample t-tests compared baseline patient characteristics. Modified Poisson regression estimated relative risks of moderate, severe, or very severe (MSVS) symptom severity, and chemotherapy-related adverse events.Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.no changes Results: In 294 patients accrued between 2014 and 2020, mean age was 58 (SD13) and 23% were Black. For anthracycline-based regimens, the only significant difference in MSVS symptoms was in lymphedema (41% Black vs 20% White, p =.04) after controlling for axillary surgery. For non-anthracycline regimens, the only significant difference was MSVS peripheral neuropathy (41% Blacks vs. 23% White) after controlling for taxane type (p =.05) and diabetes (p =.05). For all other symptoms, severity scores were similar. Dose reduction differed significantly for non-anthracycline regimens (49% Black vs. 25% White, p =.01), but not for anthracycline regimens or in dose delay, early treatment discontinuation, or hospitalization for either regimen. Conclusion: Except for lymphedema and peripheral neuropathy, Black and White patients reported similar symptom severity during adjuvant chemotherapy. Dose reductions in Black patients were more common for non-anthracycline regimens. In this sample, there were minimal differences in patient-reported symptoms and other adverse outcomes in Black versus White patients

    Time-of-flight and activation experiments on 147Pm and 171Tm for astrophysics

    Get PDF
    The neutron capture cross section of several key unstable isotopes acting as branching points in the s-process are crucial for stellar nucleosynthesis studies, but they are very challenging to measure due to the difficult production of sufficient sample material, the high activity of the resulting samples, and the actual (n,Îł) measurement, for which high neutron fluxes and effective background rejection capabilities are required. As part of a new program to measure some of these important branching points, radioactive targets of 147Pm and 171Tm have been produced by irradiation of stable isotopes at the ILL high flux reactor. Neutron capture on 146Nd and 170Er at the reactor was followed by beta decay and the resulting matrix was purified via radiochemical separation at PSI. The radioactive targets have been used for time-of-flight measurements at the CERN n-TOF facility using the 19 and 185 m beam lines during 2014 and 2015. The capture cascades were detected using a set of four C6D6 scintillators, allowing to observe the associated neutron capture resonances. The results presented in this work are the first ever determination of the resonance capture cross section of 147Pm and 171Tm. Activation experiments on the same 147Pm and 171Tm targets with a high-intensity 30 keV quasi-Maxwellian flux of neutrons will be performed using the SARAF accelerator and the Liquid-Lithium Target (LiLiT) in order to extract the corresponding Maxwellian Average Cross Section (MACS). The status of these experiments and preliminary results will be presented and discussed as well

    Measurement of the 240Pu(n,f) cross-section at the CERN n-TOF facility : First results from experimental area II (EAR-2)

    Get PDF
    The accurate knowledge of the neutron-induced fission cross-sections of actinides and other isotopes involved in the nuclear fuel cycle is essential for the design of advanced nuclear systems, such as Generation-IV nuclear reactors. Such experimental data can also provide the necessary feedback for the adjustment of nuclear model parameters used in the evaluation process, resulting in the further development of nuclear fission models. In the present work, the 240Pu(n,f) cross-section was measured at CERN's n-TOF facility relative to the well-known 235U(n,f) cross section, over a wide range of neutron energies, from meV to almost MeV, using the time-of-flight technique and a set-up based on Micromegas detectors. This measurement was the first experiment to be performed at n-TOF's new experimental area (EAR-2), which offers a significantly higher neutron flux compared to the already existing experimental area (EAR-1). Preliminary results as well as the experimental procedure, including a description of the facility and the data handling and analysis, are presented

    Characterization of the n-TOF EAR-2 neutron beam

    Get PDF
    The experimental area 2 (EAR-2) at CERNs neutron time-of-flight facility (n-TOF), which is operational since 2014, is designed and built as a short-distance complement to the experimental area 1 (EAR-1). The Parallel Plate Avalanche Counter (PPAC) monitor experiment was performed to characterize the beam prole and the shape of the neutron 'ux at EAR-2. The prompt Îł-flash which is used for calibrating the time-of-flight at EAR-1 is not seen by PPAC at EAR-2, shedding light on the physical origin of this Îł-flash

    New measurement of the 242Pu(n,Îł) cross section at n-TOF-EAR1 for MOX fuels : Preliminary results in the RRR

    Get PDF
    The spent fuel of current nuclear reactors contains fissile plutonium isotopes that can be combined with 238U to make mixed oxide (MOX) fuel. In this way the Pu from spent fuel is used in a new reactor cycle, contributing to the long-term sustainability of nuclear energy. The use of MOX fuels in thermal and fast reactors requires accurate capture and fission cross sections. For the particular case of 242Pu, the previous neutron capture cross section measurements were made in the 70's, providing an uncertainty of about 35% in the keV region. In this context, the Nuclear Energy Agency recommends in its "High Priority Request List" and its report WPEC-26 that the capture cross section of 242Pu should be measured with an accuracy of at least 7-12% in the neutron energy range between 500 eV and 500 keV. This work presents a brief description of the measurement performed at n-TOF-EAR1, the data reduction process and the first ToF capture measurement on this isotope in the last 40 years, providing preliminary individual resonance parameters beyond the current energy limits in the evaluations, as well as a preliminary set of average resonance parameters

    The measurement programme at the neutron time-of-flight facility n-TOF at CERN

    Get PDF
    Neutron-induced reaction cross sections are important for a wide variety of research fields ranging from the study of nuclear level densities, nucleosynthesis to applications of nuclear technology like design, and criticality and safety assessment of existing and future nuclear reactors, radiation dosimetry, medical applications, nuclear waste transmutation, accelerator-driven systems and fuel cycle investigations. Simulations and calculations of nuclear technology applications largely rely on evaluated nuclear data libraries. The evaluations in these libraries are based both on experimental data and theoretical models. CERN's neutron time-of-flight facility n-TOF has produced a considerable amount of experimental data since it has become fully operational with the start of its scientific measurement programme in 2001. While for a long period a single measurement station (EAR1) located at 185 m from the neutron production target was available, the construction of a second beam line at 20 m (EAR2) in 2014 has substantially increased the measurement capabilities of the facility. An outline of the experimental nuclear data activities at n-TOF will be presented

    Cross section measurements of 155,157Gd(n, Îł) induced by thermal and epithermal neutrons

    Get PDF
    Neutron capture cross section measurements on Gd and Gd were performed using the time-of-flight technique at the n_TOF facility at CERN on isotopically enriched samples. The measurements were carried out in the n_TOF experimental area EAR1, at 185 m from the neutron source, with an array of 4 CD liquid scintillation detectors. At a neutron kinetic energy of 0.0253 eV, capture cross sections of 62.2(2.2) and 239.8(8.4) kilobarn have been derived for Gd and Gd, respectively, with up to 6% deviation relative to values presently reported in nuclear data libraries, but consistent with those values within 1.6 standard deviations. A resonance shape analysis has been performed in the resolved resonance region up to 181 eV and 307 eV, respectively for Gd and Gd, where on average, resonance parameters have been found in good agreement with evaluations. Above these energies and up to 1 keV, the observed resonance-like structure of the cross section has been analysed and characterised. From a statistical analysis of the observed neutron resonances we deduced: neutron strength function of 2. 01 (28) × 10 and 2. 17 (41) × 10 ; average total radiative width of 106.8(14) meV and 101.1(20) meV and s-wave resonance spacing 1.6(2) eV and 4.8(5) eV for n + Gd and n + Gd systems, respectively

    Measurement of the 72Ge(n,Îł) cross section over a wide neutron energy range at the CERN n_TOF facility

    Get PDF
    The Ge72(n,Îł) cross section was measured for neutron energies up to 300keV at the neutron time-of-flight facility n_TOF (CERN), Geneva, for the first time covering energies relevant to heavy-element synthesis in stars. The measurement was performed at the high-resolution beamline EAR-1, using an isotopically enriched GeO272 sample. The prompt capture Îł rays were detected with four liquid scintillation detectors, optimized for low neutron sensitivity. We determined resonance capture kernels up to a neutron energy of 43keV, and averaged cross sections from 43 to 300keV. Maxwellian-averaged cross section values were calculated from kT=5 to 100keV, with uncertainties between 3.2% and 7.1%. The new results significantly reduce uncertainties of abundances produced in the slow neutron capture process in massive stars

    Neutron capture measurement at the n TOF facility of the 204Tl and 205Tl s-process branching points

    Get PDF
    Neutron capture cross sections are one of the fundamental nuclear data in the study of the s (slow) process of nucleosynthesis. More interestingly, the competition between the capture and the decay rates in some unstable nuclei determines the local isotopic abundance pattern. Since decay rates are often sensible to temperature and electron density, the study of the nuclear properties of these nuclei can provide valuable constraints to the physical magnitudes of the nucleosynthesis stellar environment. Here we report on the capture cross section measurement of two thallium isotopes, 204Tl and 205Tl performed by the time-of-flight technique at the n TOF facility at CERN. At some particular stellar s-process environments, the decay of both nuclei is strongly enhanced, and determines decisively the abundance of two s-only isotopes of lead, 204Pb and 205Pb. The latter, as a long-lived radioactive nucleus, has potential use as a chronometer of the last s-process events that contributed to final solar isotopic abundances
    corecore