51 research outputs found
Measurement of the Decay Asymmetry Parameters in and
We have measured the weak decay asymmetry parameters (\aLC ) for two \LC\
decay modes. Our measurements are \aLC = -0.94^{+0.21+0.12}_{-0.06-0.06} for
the decay mode and \aLC = -0.45\pm 0.31 \pm
0.06 for the decay mode . By combining these
measurements with the previously measured decay rates, we have extracted the
parity-violating and parity-conserving amplitudes. These amplitudes are used to
test models of nonleptonic charmed baryon decay.Comment: 11 pages including the figures. Uses REVTEX and psfig macros. Figures
as uuencoded postscript. Also available as
http://w4.lns.cornell.edu/public/CLNS/1995/CLNS95-1319.p
Observation of the Charmed Baryon Decays to , , and
We have observed two new decay modes of the charmed baryon into
and using data collected with the
CLEO II detector. We also present the first measurement of the branching
fraction for the previously observed decay mode . The branching fractions for these three modes relative to
are measured to be , , and , respectively.Comment: 12 page uuencoded postscript file, postscript file also available
through http://w4.lns.cornell.edu/public/CLN
Extensive Cardiac Function Analyses Using Contemporary Echocardiography in Childhood Cancer Survivors:A DCCSS LATER Study
Background: Childhood cancer survivors (CCS) are at risk for cardiotoxicity. Objectives: We sought to assess how cardiac dysfunction measurements in CCS overlap and are differentially influenced by risk factors. Methods: This cross-sectional Dutch Childhood Cancer Survivor Study evaluated echocardiograms of 1,397 ≥5-year CCS and 277 siblings. Of CCS, n = 1,254 received cardiotoxic (anthracyclines/mitoxantrone/radiotherapy involving the heart region [RTheart]) and n = 143 received potentially cardiotoxic (cyclophosphamide, ifosfamide, or vincristine) therapy. We assessed demographic, treatment-related, and traditional cardiovascular risk factors for cardiac dysfunction using multivariable logistic regression. Results: CCS were a median of 26.7 years after diagnosis; 49% were women. Abnormal left ventricular ejection fraction (LVEF) (defined as <52% in men, <54% in women) occurred most commonly in CCS treated with anthracyclines and RTheart combined (38%). Age/sex-specific abnormal global longitudinal strain (GLS) occurred most commonly in CCS treated with RTheart, either with (41%) or without (38%) anthracyclines. Of CCS with normal LVEF, 20.2% showed abnormal GLS. Diastolic dysfunction grade ≥II was rare. Abnormal LVEF was mainly associated with female sex, anthracycline dose, and only in women, RTheart dose. Abnormal GLS was associated with female sex, RTheart dose, diastolic blood pressure, and only in women, anthracycline dose. Cyclophosphamide, ifosfamide, and vincristine were not associated with LVEF or GLS. Compared with siblings, CCS showed higher risk of abnormal LVEF (OR: 2.9; 95% CI: 1.4-6.6) and GLS (OR: 2.1; 95% CI: 1.2-3.7), independent of (potentially) cardiotoxic treatment-related and cardiovascular risk factors. Conclusions: Abnormal LVEF and GLS constitute complementary measures of systolic dysfunction among long-term CCS. Their diagnostic value may differ according to cardiotoxic exposures. Also, CCS have residual, unexplained risk of cardiac dysfunction.</p
Extensive Cardiac Function Analyses Using Contemporary Echocardiography in Childhood Cancer Survivors:A DCCSS LATER Study
Background: Childhood cancer survivors (CCS) are at risk for cardiotoxicity.Objectives: We sought to assess how cardiac dysfunction measurements in CCS overlap and are differentially influenced by risk factors.Methods: This cross-sectional Dutch Childhood Cancer Survivor Study evaluated echocardiograms of 1,397 ≥5-year CCS and 277 siblings. Of CCS, n = 1,254 received cardiotoxic (anthracyclines/mitoxantrone/radiotherapy involving the heart region [RTheart]) and n = 143 received potentially cardiotoxic (cyclophosphamide, ifosfamide, or vincristine) therapy. We assessed demographic, treatment-related, and traditional cardiovascular risk factors for cardiac dysfunction using multivariable logistic regression.Results: CCS were a median of 26.7 years after diagnosis; 49% were women. Abnormal left ventricular ejection fraction (LVEF) (defined as <52% in men, <54% in women) occurred most commonly in CCS treated with anthracyclines and RTheart combined (38%). Age/sex-specific abnormal global longitudinal strain (GLS) occurred most commonly in CCS treated with RTheart, either with (41%) or without (38%) anthracyclines. Of CCS with normal LVEF, 20.2% showed abnormal GLS. Diastolic dysfunction grade ≥II was rare. Abnormal LVEF was mainly associated with female sex, anthracycline dose, and only in women, RTheart dose. Abnormal GLS was associated with female sex, RTheart dose, diastolic blood pressure, and only in women, anthracycline dose. Cyclophosphamide, ifosfamide, and vincristine were not associated with LVEF or GLS. Compared with siblings, CCS showed higher risk of abnormal LVEF (OR: 2.9; 95% CI: 1.4-6.6) and GLS (OR: 2.1; 95% CI: 1.2-3.7), independent of (potentially) cardiotoxic treatment-related and cardiovascular risk factors.Conclusions: Abnormal LVEF and GLS constitute complementary measures of systolic dysfunction among long-term CCS. Their diagnostic value may differ according to cardiotoxic exposures. Also, CCS have residual, unexplained risk of cardiac dysfunction.</p
Echocardiography protocol for early detection of cardiac dysfunction in childhood cancer survivors in the multicenter DCCSS LATER 2 CARD study: design, feasibility, and reproducibility
Background Cardiotoxicity is a well-known side effect after anthracyclines and chest radiotherapy in childhood cancer survivors (CCS). The DCCSS LATER 2 CARD (cardiology) study includes evaluation of echocardiographic measurements for early identification of CCS at highest risk of developing heart failure. This paper describes the design, feasibility, and reproducibility of the echocardiography protocol.Methods Echocardiograms from CCS and sibling controls were prospectively obtained at the participating centers and centrally analyzed. We describe the image acquisition, measurement protocol, and software-specific considerations for myocardial strain analyses. We report the feasibility of the primary outcomes of systolic and diastolic function, as well as reproducibility analyses in 30 subjects.Results We obtained 1,679 echocardiograms. Biplane ejection fraction (LVEF) measurement was feasible in 91% and 96% of CCS and siblings, respectively, global longitudinal strain (GLS) in 80% and 91%, global circumferential strain (GCS) in 86% and 89%, and >= 2 diastolic function parameters in 99% and 100%, right ventricle free wall strain (RVFWS) in 57% and 65%, and left atrial reservoir strain (LASr) in 72% and 79%. Intra-class correlation coefficients for inter-observer variability were 0.85 for LVEF, 0.76 for GLS, 0.70 for GCS, 0.89 for RVFWS and 0.89 for LASr. Intra-class correlation coefficients for intra-observer variability were 0.87 for LVEF, 0.82 for GLS, 0.82 for GCS, 0.85 for RVFWS and 0.79 for LASr.Conclusion The DCCSS LATER 2 CARD study includes a protocolized echocardiogram, with feasible and reproducible primary outcome measurements. This ensures high-quality outcome data for prevalence estimates and for reliable comparison of cardiac function parameters.Diabetes mellitus: pathophysiological changes and therap
Diagnostic tools for early detection of cardiac dysfunction in childhood cancer survivors: Methodological aspects of the Dutch late effects after childhood cancer (LATER) cardiology study
Background: Cancer therapy-related cardiac dysfunction and heart failure are major problems in long-term childhood cancer survivors (CCS). We hypothesize that assessment of more sensitive echo- and electrocardiographic measurements, and/or biomarkers will allow for improved recognition of patients with cardiac dysfunction before heart failure develops, and may also identify patients at lower risk for heart failure. Objective: To describe the methodology of the Dutch LATER cardiology study (LATER CARD). Methods: The LATER CARD study is a cross-sectional study in long-term CCS treated with (potentially) cardiotoxic cancer therapies and sibling controls. We will evaluate 1) the prevalence and associated (treatment related) risk factors of subclinical cardiac dysfunction in CCS compared to sibling controls and 2) the diagnostic value of echocardiography including myocardial strain and diastolic function parameters, blood biomarkers for cardiomyocyte apoptosis, oxidative stress, cardiac remodeling and inflammation and ECG or combinations of them in the surveillance for cancer therapy-related cardiac dysfunction. From 2017 to 2020 we expect to include 1900 CCS and 500 siblings. Conclusions: The LATER CARD study will provide knowledge on different surveillance modalities for detection of cardiac dysfunction in long-term CCS at risk for heart
Condensate Retention and Shedding Effects on Air-Side Heat Exchanger Performance
The effects of condensation on the air-side performance of plate-fin-tube heat
exchangers have been experimentally investigated by conducting experiments under dry
conditions and then repeating these experiments under condensing conditions. Sensible air-side
heat transfer coefficients and friction factors are reported and compared for these cases. Realtime
and steady-state measurements of condensate retention are reported for both coated and
uncoated heat exchangers with fin spacings of 4, 8, 10 and 12 fpi (fins per inch). An initial
model has been developed to predict the quantity of condensate retained on plate-fin-tube heat
exchangers with wide fin spacings as a function of the heat exchanger geometry, advancing
and receding contact angles, and air-side Reynolds number. This model demonstrates
condensate retention modeling techniques and possible improvements to these techniques are
discussed. Experiments were conducted in an optically accessible test section and photographs
of retained condensate are provided. These photographs identify the modes of condensation
and condensate geometries observed during the experiments. Advancing and receding contact
angle were measured using a contact angle goniometer for typical heat transfer surfaces. These
measurements indicated a significant increase in surface wettability during the first 100 hours
of wet-dry cycling.Air Conditioning and Refrigeration Project 6
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