73 research outputs found
Temporal Stability and Geographic Variation in Cumulative Case Fatality Rates and Average Doubling Times of SARS Epidemics
We analyze temporal stability and geographic trends in cumulative case fatality rates and average doubling times of severe acute respiratory syndrome (SARS). In part, we account for correlations between case fatality rates and doubling times through differences in control measures. We discuss factors that may alter future estimates of case fatality rates. We also discuss reasons for heterogeneity in doubling times among countries and the implications for the control of SARS in different countries and parameterization of epidemic models
Severe Acute Respiratory Syndrome: Temporal Stability and Geographic Variation in Death Rates and Doubling Times
We analyzed temporal stability and geographic trends in cumulative case-fatality rates and average doubling times of severe acute respiratory syndrome (SARS). In part, we account for correlations between case-fatality rates and doubling times through differences in control measures. Factors that may alter future estimates of case-fatality rates, reasons for heterogeneity in doubling times among countries, and implications for the control of SARS are discussed
Coordination of H2O2 on praseodymia nanorods and its application in sensing cholesterol
The advancement of functional nanomaterials has promoted the development of biomarker sensors underpinning promising analytical tools for a range of bioanalytes such as cholesterol. In this work, we established a light-on fluorescent probe for cholesterol in human serum by coordination of H2O2 on the surface of praseodymia nanorods (Pr6O11 NRs). The distinctive interactions of various nucleotides and H2O2 with praseodymia were examined, whereby good fluorescent quenching and recovery capability were observed. A highly sensitive and selective cholesterol detection was achieved in serum samples with a detection limit of 0.1 mu M and recovery of 97.2-101.3%, respectively, due to the high oxygen mobility of praseodymia. The result suggests strong potential for work towards a key probe for a portable clinical test system for cholesterol as well as other H2O2-deriving biomarkers, potentially addressing the ever-increasing demand for the prevention of cardiovascular disease. (C) 2022 Vietnam National University, Hanoi. Published by Elsevier B.V.This work was supported by the Natural Science Foundation of Shandong Province (Grant ZR2017LB028) , Key R&D Program of Shandong Province (Grant 2018GSF118032) , and Fundamental Research Funds for the Central Universities (Grant 18CX02125A) in China. The project with reference number of ENE2017-82451-C3-2-R from Ministry of Science, Innovation and Universities of Spain is also acknowledged. This work has been co-financed by the 2014-2020 ERDF Operational Programme and by the Department of Economy, Knowledge, Business and University of the Regional Government of Andalusia with reference number of FEDER-UCA18-107316
Nonparametric Estimation of the Case Fatality Ratio with Competing Risks Data: An Application to Severe Acute Respiratory Syndome (SARS)
For diseases with some level of associated mortality, the case fatality ratio measures the proportion of diseased individuals who die from the disease. In principle, it is straightforward to estimate this quantity from individual follow-up data that provides times from onset to death or recovery. In particular, in a competing risks context, the case fatality ratio is defined by the limiting value of the sub-distribution function, associated with death, at infinity. When censoring is present, however, estimation of this quantity is complicated by the possibility of little information in the right tail of of the sub-distribution function, requiring use of estimators evaluated at large or the largest observed death times. With right censoring, the variability of such estimators is large in the tail, suggesting the possibility of using estimators evaluated at smaller death times where bias may be increased but overall mean squared error be smaller. These issues are investigated here for nonparametric estimators of the sub-distribution functions for both death and recovery. The ideas are illustrated on case fatality data for individuals infected with severe acute respiratory syndrome (SARS) in Hong Kong in 2003
Functional consequence of the MET-T1010I polymorphism in breast cancer.
Major breast cancer predisposition genes, only account for approximately 30% of high-risk breast cancer families and only explain 15% of breast cancer familial relative risk. The HGF growth factor receptor MET is potentially functionally altered due to an uncommon germline single nucleotide polymorphism (SNP), MET-T1010I, in many cancer lineages including breast cancer where the MET-T1010I SNP is present in 2% of patients with metastatic breast cancer. Expression of MET-T1010I in the context of mammary epithelium increases colony formation, cell migration and invasion in-vitro and tumor growth and invasion in-vivo. A selective effect of MET-T1010I as compared to wild type MET on cell invasion both in-vitro and in-vivo suggests that the MET-T1010I SNP may alter tumor pathophysiology and should be considered as a potential biomarker when implementing MET targeted clinical trials
Analytical Solutions to H2 and H∞ Optimizations of Resonant Shunted Electromagnetic Tuned Mass Damper and Vibration Energy Harvester
Exfoliated Triazine-Based Covalent Organic Nanosheets with Multielectron Redox for High-Performance Lithium Organic Batteries
The development of the next-generation lithium ion battery requires environmental-friendly electrode materials with long cycle life and high energy density. Organic compounds are a promising potential source of electrode materials for lithium ion batteries due to their advantages of chemical richness at the molecular level, cost benefit, and environmental friendliness, but they suffer from low capacity and dissatisfactory cycle life mainly due to hydrophobic dissolution in organic electrolytes and poor electronic conductivity. In this work, two types of triazine-based covalent organic nanosheets (CONs) are exfoliated and composited with carbon nanotubes. The thin-layered 2D structure for the exfoliated CONs can activate more functional groups for lithium storage and boost the utilization efficiency of redox sites compared to its bulk counterpart. Large reversible capacities of above 1000 mAh g−1 can be achieved after 250 cycles, which is comparable to high-capacity inorganic electrodes. Moreover, the lithium-storage mechanism is determined to be an intriguing 11 and 16 electron redox reaction, associated with the organic groups (unusual triazine ring, piperazine ring, and benzene ring, and common C=N, -NH- groups)
Bivariate current status data with univariate monitoring times
For bivariate current status data with univariate monitoring times, the identifiable part of the joint distribution is three univariate cumulative distribution functions, namely the two marginal distributions and the bivariate cumulative distribution function evaluated on the diagonal. We show that smooth functionals of these univariate cumulative distribution functions can be efficiently estimated with easily computed nonparametric maximum likelihood estimators based on reduced data consisting of univariate current status observations. This theory is then applied to functionals that address independence of the two survival times and the goodness-of-fit of a copula model used by Wang & Ding (2000). Some brief simulations are provided along with an illustration based on data on HIV transmission. Extension of the ideas to incorporate covariates, possibly time-dependent, are discussed. Copyright 2005, Oxford University Press.
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Hyponatremia in hospitalized cancer patients and its impact on clinical outcomes.
BackgroundHyponatremia is the most common electrolyte abnormality in clinical practice, yet little is known about its frequency in patients with cancer or its impact on their clinical outcomes.Study designRetrospective analysis of prospectively collected data.Setting & participantsPatients with cancer admitted to the University of Texas M.D. Anderson Cancer Center in 2006 for 3 months.PredictorSerum sodium levels categorized as eunatremia (serum sodium, 135-147 mEq/L) and mild (134-130 mEq/L), moderate (129-120 mEq/L), and severe (<120 mEq/L) hyponatremia.Outcomes(1) Length of hospital stay and (2) 90-day mortality.ResultsIn 4,702 admissions in 3,357 patients with cancer, hyponatremia (serum sodium <135 mEq/L) was noted in 47% of admissions. It was mild in 36%, moderate in 10%, and severe in 1%. Hyponatremia was acquired during the hospital stay in 24%. Using the first admission data, mean length of stay was 5.6 ± 5.0 days for patients with eunatremia and 9.9 ± 9.2, 13.0 ± 14.1, and 11.5 ± 12.6 days for those with mild, moderate, and severe hyponatremia, respectively. The respective HRs in the multivariate Cox model for longer hospital stay, using patients with eunatremia as reference, were 1.92 (95% CI, 1.75-2.13; P < 0.01), 2.94 (95% CI, 2.56-3.45; P < 0.01), and 2.32 (95% CI, 1.32-4.00; P = 0.01). 283 (8.4%) deaths occurred during 90 days, and in the multivariate model, the respective HRs for 90-day mortality for mild, moderate, and severe hyponatremia were 2.04 (95% CI, 1.42-2.91; P < 0.01); 4.74 (95% CI, 3.21-7.01; P < 0.01), and 3.46 (95% CI, 1.05-11.44; P = 0.04). These findings were consistent when analyses were repeated with sodium levels in tertiles.LimitationsObservational study, retrospective, inability to adjust for all comorbid conditions.ConclusionHyponatremia in patients with cancer is associated with longer hospital stay and higher mortality. Whether long-term correction of hyponatremia would improve these outcomes remains to be determined
Delayed initiation of adjuvant chemotherapy in older women with breast cancer
Abstract Background Adjuvant chemotherapy benefits early‐stage breast cancer (BC) patients. Older women receive guideline‐adherent treatment less frequently and experience treatment delays more frequently. We evaluated factors associated with delaying adjuvant chemotherapy and the delays’ survival impact in a large population–based cohort of elderly BC patients. Methods Patients age >66 years diagnosed 2001‐2015 with localized or regional BC were identified in the SEER‐Medicare and Texas Cancer Registry‐Medicare databases. Time from surgery to chemotherapy (TTC) was categorized into four groups: 0‐30, 31‐60, 61‐90, and >90 days. We identified predictors of delays, estimated overall (OS) and BC‐specific (BCSS) survival, and determined the association between TTC and outcome adjusting for other variables. Results Among 28,968 women (median age 71 years), median TTC was 43 days. 10.7% of patients experienced TTC >90 days. Older age, Black or Hispanic race/ethnicity, unmarried status, more comorbidities, hormone receptor‐positivity, mastectomy, Oncotype DX testing, and full state buy‐in were associated with increased risk of delay. Five‐year OS estimates by TTC group were 0.82, 0.81, 0.80, and 0.74, respectively (p<.001). BCSS demonstrated a similar trend (p<.001). Chemotherapy delay was associated with worse OS (HR=1.33, 95%CI 1.25‐1.40) and BCSS (HR=1.39, 95%CI 1.27‐1.53). In subgroup analysis, delayed chemotherapy was associated with worse OS and BCSS among patients with hormone receptor–positive (HR=1.56, 95%CI 0.97‐2.51), HER2‐positive (HR=1.99, 95%CI 1.04‐3.79), and triple‐negative (HR=2.15, 95%CI 1.38‐3.36) tumors. Conclusion Chemotherapy delays are associated with worse survival in older BC patients. Providers should avoid delays and initiate chemotherapy ≤90 days after surgery regardless of patients’ BC subtype or age
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