We report heterogeneity in the time necessary for Exonuclease I to hydrolyze identical DNA fragments. A real-time fluorescence method measured the time required by molecules of Exonuclease I to hydrolyze single-stranded DNA that was synthesized to have two fluorescently labeled nucleotides. One fluorescently labeled nucleotide was located near the 3' end of the DNA and the other near the 5' end. Heterogeneity in the hydrolysis rate of the exonuclease population was inferred from the distribution of times necessary to cleave these DNA fragments. In particular, we found simple first-order kinetics, using a single hydrolysis rate, did not result in a good fit to the data. Better fits to the data were obtained if one assumed a distribution of hydrolysis rates for the exonuclease population. Under our experimental conditions, this broad distribution of rates was centered near 100 nt/s.
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http://dx.doi.org/10.1529/biophysj.104.044255 | DOI Listing |
Behav Res Methods
January 2025
Department of Data Analysis, Ghent University, Henri Dunantlaan 1, 9000, Ghent, Belgium.
Model estimation for SEM analyses in commonly used software typically involves iterative optimization procedures, which can lead to nonconvergence issues. In this paper, we propose using random starting values as an alternative to the current default strategies. By drawing from uniform distributions within data-driven lower and upper bounds (see De Jonckere et al.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Biostatistics, Data Science and Epidemiology, School of Public Health, Augusta University, 1120, 15th Street, Augusta, GA, 30912, USA.
Compartmental models with exponentially distributed lifetime stages assume a constant hazard rate, limiting their scope. This study develops a theoretical framework for systems with general lifetime distributions, modeled as transition rates in a renewal process. Applications are provided for the SVIS (Susceptible-Vaccinated-Infected-Susceptible) disease epidemic model to investigate the impacts of hazard rate functions (HRFs) on disease control.
View Article and Find Full Text PDFMol Pharm
January 2025
Key Laboratory of Natural Medicines of the Changbai Mountain, Ministry of Education, College of Pharmacy, Yanbian University, Yanji 133002, China.
The morbidity and mortality rates of hepatocellular carcinoma (HCC) are high and continue to increase. The antitumor effects of single therapies are limited because of tumor heterogeneity and drug resistance, and the lack of real-time monitoring of tumor progression during the treatment process leads to poor therapeutic outcomes. Therefore, novel nanodelivery platforms combining tumor therapy and diagnosis have garnered extensive attention.
View Article and Find Full Text PDFHealth Serv Res
January 2025
Schaeffer Center for Health Policy & Economics, Price School of Public Policy, University of Southern California, Los Angeles, California, USA.
Objective: To understand how Medicare Advantage (MA) networks impact utilization patterns and plan choices, using the 2019 discontinuation of MA 1876 Cost plans as a natural experiment.
Study Setting And Design: We study 1876 Cost plans, MA plans for which out-of-network care is covered through traditional Medicare (TM) and many of which CMS discontinued in 2019. We characterize the proportion of Cost plan enrollees who utilized out-of-network care in 2018 from different types of medical specialties.
Clin Neurol Neurosurg
January 2025
Department of Neurosurgery, Aga Khan University, Karachi, Sindh, Pakistan. Electronic address:
Objectives: To provide information about implementation, resources, practice patterns and prevalent perceptions regarding neuro-oncology tumor boards (NOTBs) in a lower middle income country.
Methods: A nationwide survey was designed to include licensed neurosurgeons involving data on practice, structure, and perceptions of NOTBs with non-probability sampling, a pre-validated proforma, data analysis using SPSS v27, and geospatial mapping using Quantum GIS.
Results: 139 neurosurgeons were surveyed from 63 neurosurgical centers of a lower middle income country.
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