258 research outputs found
Constraining the period of the ringed secondary companion to the young star J1407 with photographic plates
Context. The 16 Myr old star 1SWASP J140747.93-394542.6 (V1400 Cen) underwent
a series of complex eclipses in May 2007, interpreted as the transit of a giant
Hill sphere filling debris ring system around a secondary companion, J1407b. No
other eclipses have since been detected, although other measurements have
constrained but not uniquely determined the orbital period of J1407b. Finding
another eclipse towards J1407 will help determine the orbital period of the
system, the geometry of the proposed ring system and enable planning of further
observations to characterize the material within these putative rings. Aims. We
carry out a search for other eclipses in photometric data of J1407 with the aim
of constraining the orbital period of J1407b. Methods. We present photometry
from archival photographic plates from the Harvard DASCH survey, and Bamberg
and Sonneberg Observatories, in order to place additional constraints on the
orbital period of J1407b by searching for other dimming and eclipse events.
Using a visual inspection of all 387 plates and a period-folding algorithm we
performed a search for other eclipses in these data sets. Results. We find no
other deep eclipses in the data spanning from 1890 to 1990, nor in recent
time-series photometry from 2012-2018. Conclusions. We rule out a large
fraction of putative orbital periods for J1407b from 5 to 20 years. These
limits are still marginally consistent with a large Hill sphere filling ring
system surrounding a brown dwarf companion in a bound elliptical orbit about
J1407. Issues with the stability of any rings combined with the lack of
detection of another eclipse, suggests that J1407b may not be bound to J1407.Comment: 8 pages, 3 tables, 4 figures, accepted for publication in A&A. LaTeX
files of the paper, scripts for the figures, and a minimal working FPA can be
found under https://github.com/robinmentel/Constraining-Period
Patient characteristics and health system factors associated with adjuvant radiation therapy receipt in older women with early-stage endometrial cancer
Introduction: Among women with early-stage endometrial cancer (EC), age, stage, grade, and histology are used to determine fitness for adjuvant radiation therapy (RT) administration. We examined non-cancer factors associated with adjuvant RT receipt in older women with early-stage EC. Materials & methods: Using data from the Surveillance Epidemiology and End Results cancer registry program linked with Medicare claims, we identified 25,654 women (aged ≥66 years) diagnosed with first primary stage I-II EC during 2004–2017 who underwent a hysterectomy. Diagnosis and procedure codes were used to identify adjuvant RT claims filed for the seven-month period post-hysterectomy. Multivariable log-binomial regression was used to estimate adjuvant RT prevalence associated with patient characteristics and health system factors after adjustment for age, frailty, and endometrial factors. Results: Adjuvant RT was less commonly administered to Asian American and Pacific Islander patients than non-Hispanic White patients (Prevalence ratio [PR], 0.84; 95% confidence interval [CI], 0.73 to 0.97). Compared to women treated in the Northeast region, women treated other regions of the US were less likely to undergo adjuvant RT (PR, 0.75; 95% CI, 0.71 to 0.79). Residing in rural or high neighborhood-poverty counties was associated with lower adjuvant RT administration. Higher comorbidity score was not associated with reduced prevalence of adjuvant RT receipt; however, women with high probability of predicted probability of frailty were less likely to undergo adjuvant RT (PR, 0.67; 95% CI, 0.55 to 0.81) compared to women with low probability of frailty. Women who received lymph node assessment were more likely to undergo adjuvant RT compared to women who did not (PR, 1.43; 95% CI, 1.34 to 1.51). Women treated by a gynecologic oncologist were more likely to undergo adjuvant RT compared to women treated by a non-gynecologic oncologist (PR 1.09; 95% CI, 1.04 to 1.14). Adjuvant RT was more commonly administered to women treated in larger academic hospitals. Discussion: Findings suggest that various non-cancer factors affect the delivery of adjuvant RT to older women with early-stage EC in real-world oncology practice. Advancing our understanding of factors associated with adjuvant RT administration may help expand equitable access to RT
Adjuvant radiation therapy and health-related quality of life among older women with early-stage endometrial cancer: an analysis using the SEER-MHOS linkage
Purpose: Radiation therapy (RT) has been associated with decreased health-related quality of life (HRQOL) in clinical trials of early-stage endometrial cancer (EC), but few studies have examined the association in real-world settings. We assessed HRQOL associated with adjuvant RT for older women with early-stage EC within a large U.S. population-based registry resource. Methods: The Surveillance Epidemiology and End Results and the Medicare Health Outcomes Survey linkage (1998–2017) was used to identify women with early-stage EC aged ≥ 65 years at survey who received surgery and were diagnosed ≥ 1-year prior (n = 1,140). HRQOL was evaluated with the 36-item Short-Form Health Survey (SF-36) until 2006 and the Veterans RAND 12-Item Health Survey (VR-12) post 2006. Ordinary least squares regression was used to estimate mean difference (MD) in T scores and 95% confidence intervals (CIs) comparing treatment groups (surgery alone, adjuvant external beam radiation therapy [EBRT], or adjuvant vaginal brachytherapy [VBT]) after accounting for confounders using propensity score weighting. Results: Overall, RT was not associated with physical health (MD = 0.97; 95% CI = − 1.13, 3.07) or mental health (MD = − 0.78; 95% CI = − 2.60, 1.05) relative to surgery alone. In analyses by RT type, adjuvant VBT was associated with better general health on the SF-36/VR-12 subscale (MD = 3.59; 95% CI = 0.56, 6.62) relative to surgery alone. No statistically significant associations were observed for adjuvant VBT and physical or mental health, or for adjuvant EBRT and any HRQOL domain. Conclusion: Older women with early-stage EC treated with adjuvant RT did not report worse physical and mental HRQOL scores compared to those treated with surgery alone, though relevant symptoms should be evaluated further to fully understand the disease and treatment specific aspects of the HRQOL
Real-world treatment patterns and outcomes for patients with advanced melanoma treated with immunotherapy or targeted therapy
Objective: To identify real-world patterns of first line treatment, treatment sequence and outcomes for older adults diagnosed with advanced melanoma who received immunotherapy or targeted therapy. Methods: The study population included older adults (ages 65+) diagnosed with unresectable or metastatic melanoma between 2012 and 2017 and who received first line immunotherapy or targeted therapy. Using the linked surveillance, epidemiology, and end results-medicare data, we described patterns of first line treatment and treatment sequence through 2018. We used descriptive statistics to report patient and provider characteristics by first line treatment receipt and changes in first line therapy use over calendar time. We also described overall survival (OS) and time to treatment failure (TTF) by first line treatment using the Kaplan–Meier method. For patterns of treatment sequence, we reported commonly observed treatment switch patterns by treatment sub-category and calendar year. Results: The analyses included 584 patients (mean age = 76.3 years). A majority (n = 502) received first line immunotherapy. There was a sustained increase in immunotherapy uptake, most notably from 2015 to 2016. The estimated median OS and TTF were longer with first line immunotherapy than with targeted therapy. Individuals treated with CTLA-4 + PD-1 inhibitors had the longest median OS (28.4 months). The most common treatment switch pattern was from a first line CTLA-4 inhibitor to a second line PD-1 inhibitor. Conclusions: Our findings inform understanding of treatment patterns of currently used immunotherapies and targeted therapies in older adults with advanced melanoma. Immunotherapy use has increased steadily with PD-1 inhibitors becoming a dominant treatment option since 2015
Incidence and risk factors of non-device-associated urinary tract infections in an acute-care hospital
Objective: To update current estimates of non-device-associated pneumonia (ND pneumonia) rates and their frequency relative to ventilator associated pneumonia (VAP), and identify risk factors for ND pneumonia.Design: Cohort study.Setting: Academic teaching hospital.Patients: All adult hospitalizations between 2013 and 2017 were included. Pneumonia (device associated and non-device associated) were captured through comprehensive, hospital-wide active surveillance using CDC definitions and methodology.Results: From 2013 to 2017, there were 163,386 hospitalizations (97,485 unique patients) and 771 pneumonia cases (520 ND pneumonia and 191 VAP). The rate of ND pneumonia remained stable, with 4.15 and 4.54 ND pneumonia cases per 10,000 hospitalization days in 2013 and 2017 respectively (P =.65). In 2017, 74% of pneumonia cases were ND pneumonia. Male sex and increasing age we both associated with increased risk of ND pneumonia. Additionally, patients with chronic bronchitis or emphysema (hazard ratio [HR], 2.07; 95% confidence interval [CI], 1.40-3.06), congestive heart failure (HR, 1.48; 95% CI, 1.07-2.05), or paralysis (HR, 1.72; 95% CI, 1.09-2.73) were also at increased risk, as were those who were immunosuppressed (HR, 1.54; 95% CI, 1.18-2.00) or in the ICU (HR, 1.49; 95% CI, 1.06-2.09). We did not detect a change in ND pneumonia risk with use of chlorhexidine mouthwash, total parenteral nutrition, all medications of interest, and prior ventilation.Conclusion: The incidence rate of ND pneumonia did not change from 2013 to 2017, and 3 of 4 nosocomial pneumonia cases were non-device associated. Hospital infection prevention programs should consider expanding the scope of surveillance to include non-ventilated patients. Future research should continue to look for modifiable risk factors and should assess potential prevention strategies
Incidence and risk factors of non-device-associated pneumonia in an acute-care hospital
Objective: To update current estimates of non-device-associated pneumonia (ND pneumonia) rates and their frequency relative to ventilator associated pneumonia (VAP), and identify risk factors for ND pneumonia. Design: Cohort study. Setting: Academic teaching hospital. Patients: All adult hospitalizations between 2013 and 2017 were included. Pneumonia (device associated and non-device associated) were captured through comprehensive, hospital-wide active surveillance using CDC definitions and methodology. Results: From 2013 to 2017, there were 163,386 hospitalizations (97,485 unique patients) and 771 pneumonia cases (520 ND pneumonia and 191 VAP). The rate of ND pneumonia remained stable, with 4.15 and 4.54 ND pneumonia cases per 10,000 hospitalization days in 2013 and 2017 respectively (P =.65). In 2017, 74% of pneumonia cases were ND pneumonia. Male sex and increasing age we both associated with increased risk of ND pneumonia. Additionally, patients with chronic bronchitis or emphysema (hazard ratio [HR], 2.07; 95% confidence interval [CI], 1.40-3.06), congestive heart failure (HR, 1.48; 95% CI, 1.07-2.05), or paralysis (HR, 1.72; 95% CI, 1.09-2.73) were also at increased risk, as were those who were immunosuppressed (HR, 1.54; 95% CI, 1.18-2.00) or in the ICU (HR, 1.49; 95% CI, 1.06-2.09). We did not detect a change in ND pneumonia risk with use of chlorhexidine mouthwash, total parenteral nutrition, all medications of interest, and prior ventilation. Conclusion: The incidence rate of ND pneumonia did not change from 2013 to 2017, and 3 of 4 nosocomial pneumonia cases were non-device associated. Hospital infection prevention programs should consider expanding the scope of surveillance to include non-ventilated patients. Future research should continue to look for modifiable risk factors and should assess potential prevention strategies
A comparative study of the electrochemical properties of vitamin B-6 related compounds at physiological pH
A comparative study of vitamin B6 group and related compounds in buffered solutions using electrochemical techniques has been performed at neutral pH. Irreversible bi- or tetra-electronic processes are observed for these substances, and the electron transfer coefficient (αn) calculated. It was concluded that either the first or second electron transfer were the rate determining step of the electrode process. The diffusion coefficient of these substances was calculated and the values given follow an inverse tendency to the molecular size. For aldehydes the values obtained were corrected of the hydration reaction.
It is important to remark that catalytic waves were reported for the first time for these compounds. Using a model involving the nitrogen of the basic structure the kinetic constants were calculated for most of them
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Propriedades químicas de uma Terra Roxa Estruturada influenciadas pela cobertura vegetal de inverno e pela adubação orgânica e mineral
O presente trabalho teve por objetivo avaliar a influência da cobertura vegetal de inverno, constituída de uma associação de aveia preta (Avena strigosa Schreb) com nabo forrageiro (Raphanus sativus L.), da adubação orgânica com esterco de aves e da adubação mineral sobre propriedades químicas de uma Terra Roxa Estruturada do estado de Santa Catarina. As análises foram realizadas em amostras de solo coletadas em agosto de 1994 e janeiro de 1995, nas profundidades de 0-10, 10-20 e 20-30 cm, em um experimento iniciado em 1990. Observou-se que a cobertura vegetal de inverno mostrou-se eficiente na manutenção de nutrientes, especialmente o potássio, e dos níveis de carbono orgânico, dentro dos limites da camada arável. O uso de adubo orgânico proporcionou acúmulo de nutrientes no solo, enquanto os adubos organomineral e mineral mostraram tendência de redução, principalmente dos níveis de potássio do solo
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