Austempering transformation kinetics of austempered ductile iron obtained by Mössbauer Spectroscopy

The composition of metallic matrix in ductile iron as-cast and after austempering at temperatures of 280, 330 and 380oC (ADI) was examined. The study presents the results of these examinations obtained by Mössbauer spectroscopy. The specimens were taken from cast rods of 60mm diameter. Using calculated values of the parameters of hyperfine interactions (isomeric shift IS, quadrupole splitting QS and hyperfine effective magnetic field H), isolated by deconvolution of the experimental spectrum, the constituents of the metallic matrix were identified in terms of both quantity and quality. The measured values as well as the data compiled in literature indicate that component Z1 (the, so called, Zeeman spectrum sextet) is related with 57Fe atoms present in the structure of ferrite α1 (I stage of o→α1 + st transformation), component Z2 is typical of ferrite α2 (II stage of st→α2 + carbides transformation), while component Z3 has its origin in 57Fe atoms seated in the structure of carbides (Fe3C, Fe2C or Fe2,4C). On the other hand, by analysis of the parameters of hyperfine interactions describing the non-magnetic components (L and Q) it has been proved that they are typical of austenite

Impact of Pooling Samples on Analytic Sensitivity of a Real-Time Reverse Transcriptase PCR Assay for SARS CoV-2

During the COVID-19 pandemic, laboratories experienced periods of shortages for certain critical materials required to meet the high demand for SARS-CoV-2 testing. The U.S. Food & Drug Administration provided a template for molecular diagnostic testing, including guidance for a specimen pooling process in order to evaluate performance of the SARS-CoV-2 nucleic acid amplification assay. This study aimed to evaluate the testing of pooled specimens consisting of four nasopharyngeal swab specimens using the Luminex ARIES® nucleic acid amplification platform. Results indicated that there was a loss of analytic sensitivity with pooled nasopharyngeal swab samples, demonstrating that this approach should be balanced against material shortages and the clinical utility of a less sensitive assay

Association of Urine Levels of C-Reactive Protein with Clinical Outcomes in Patients with Pneumonia: A Pilot Study

Finding relevant biomarkers as a potential predictor of severity for patients hospitalized with community acquired pneumonia (CAP), in addition to the clinical scoring system, could advance progress towards more effective patient management. The inflammatory marker, C-reactive protein (CRP), which is elevated in the pathogenesis of many infectious diseases, may be a key biomarker target for CAP. Previous studies have shown that serum CRP may be a useful diagnostic marker for pneumonia in hospitalized patients with acute respiratory symptoms. The main aims of this study were to determine the correlation between serum and urine CRP levels in hospitalized patients with CAP, and any correlation with patient outcomes. Our laboratory employed a commercially available human high sensitive CRP ELISA kit to check the level of CRP in the corresponding patient urine sample. The results showed that there was a positive correlation between patient serum and urine CRP levels. In addition, we showed the correlation of urine CRP levels with certain patient comorbidities, time to clinical stability, length of patient hospital stay, and mortality

Characteristics and Clinical Outcomes of Hospitalized Patients with Community-Acquired Pneumonia who are Active Intravenous Drug Users

Background: Intravenous drug users (IVDU) have a 10-fold increased risk of community-acquired pneumonia (CAP) compared to the general population. There is scarce data available evaluating the clinical outcomes of IVDU hospitalized patients with CAP and that data mostly focuses on mortality. The objective of this study was to evaluate the clinical characteristics, incidence and outcomes of hospitalized patients with CAP in active intravenous drug users in Louisville, Kentucky. Methods: This was a secondary data analysis of the University of Louisville Pneumonia study. IVDU patients were propensity score matched to a non-IVDU group. Study outcomes were time to clinical stability (TCS), length of stay (LOS), mortality at discharge, and mortality at 1 year. Stratified Cox proportional hazard regression was performed to evaluate TCS and LOS. Conditional logistic regression was performed to evaluate mortality. Statistical significance was defined as p ≤ 0.05. Results:From a total of 8,284 hospitalized patients with CAP reviewed, 113 patients were matched per group. Median (IQR) age for the IVDU was 33 (28-43) versus 36 (28-48) for the matched non-IVDU group (p Conclusions: This study shows that active IVDU hospitalized patients with CAP do not have worse outcomes when compared with non-IVDU hospitalized patients with CAP. Patients in the IVDU group were significantly younger. Since severity scores commonly used are heavily influenced by age, these will not likely be useful tools to assist the physicians with the site for care and management

The effect of cooling rate on the microstructure of nodular cast iron

Abstract The study gives the results of the investigations concerning an effect of the casting cooling rate ( casting made from nodular iron used as a starting material for austempering to produce ADI) on the morphology of nodular graphite and metallic matrix composition. The features of the microstructure morphology were determined on a LUCIA computer program using castings of 10, 20, 40 and 60 mm diameter. It has been proved that increasing the casting diameter from 10 to 60 mm (i.e. reducing the cooling rate) increases the content of graphite from 10 to 12% and an average area of the precipitations from about 150 to 440 µm 2 , while it reduces the number of the graphite precipitations in 1 mm 2 from about 700 to 260, the mean value of the shape factor from 0,96 to 0,84, and pearlite content in the matrix from about 96% to 84%. The chemical composition seems to have no significant effect, the only exception being Mo whose presence increases in a visible way pearlite content in the matrix at each cooling rate. The obtained results, and specifically the distribution of the frequencies of occurrence of the examined morphological features of graphite, confirm the vast possibilities that the LUCIA computer program of image analysis offers in evaluation of the effect of technological parameters on cast iron microstructure

Distributing Data and Analysis Software Containers For Better Data Sharing in Clinical Research

Introduction: Data sharing in clinical research is critical for increasing knowledge discovery. Data and software tools should be FAIR: Findable, Accessible, Inter-operable and Re-usable. Many bottlenecks exist in the process of a clinical investigator using shared data including data acquisition and statistical analysis. The objective of this project is to develop a structure for sharing data and providing rapid automated statistical analysis through creation of a pre-packaged, open-source software container. Methods: We use the open source software container technologies VirtualBox and Vagrant to create a template for sharing clinical data and analysis scripts as a single container. We use a timer to record the time necessary to setup and initialize the software container and view the results. Results: We have created a template for sharing data and analysis scripts together using open source software container technologies VirtualBox and Vagrant. We found the time needed to initialize the container to be 5 minutes and 36 seconds for a macOS-based machine and 7 minutes and 2 seconds for a Windows-based machine. Containers can be downloaded and executed from any Mac or Windows computer allowing both the reuse of and interaction with the data. This greatly reduces the time and effort needed to obtain and analyze clinical data. Conclusion: Reducing the time and effort needed to obtain and analyze clinical data increases the time available for data exploration and the discovery of new knowledge. This can be effectively achieved using software containers and virtualization

Assessment of Pneumonia Severity Indices as Mortality Predictors

BACKGROUND The leading cause of infectious disease death in the United States is community-acquired pneumonia (CAP). Several pneumonia severity indices exist and are widely used as tools to assist physicians regarding site of care based on risk of death. However, limited data exists that discerns which of the most commonly used severity scores is the best predictor of mortality across multiple time points. The objective of this study is to determine the best mortality predictor at different time points between four of the most commonly used pneumonia severity scores. METHODS This was a secondary analysis of a prospective, multicenter, population-based, observational study of patients hospitalized with CAP in the city of Louisville, KY. The severity indices used were the American Thoracic Society (ATS) criteria, the Pneumonia Severity Index (PSI), the British Thoracic Society criteria (CURB-65), Quick Sepsis-Related Organ Failure Assessment (QSOFA), and direct ICU admission to represent physician discretion. The accuracy, kappa statistic, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for the ability to predict in-hospital, 30-day, 6-month, and 1-year mortality. 95% confidence intervals for each variable were generated by bootstrapping with random sampling and resampling of the subjects 1000 times. In addition, the area under the curve (AUC) was calculated for each severity score and mortality time point. RESULTS There were 6013 eligible patients included in this analysis with data collected between the years 2014 and 2016. At each time point, the QSOFA had the highest sensitivity and NPV, while the PSI had the highest specificity and PPV. QSOFA had the highest accuracy for in-hospital mortality, 30-day mortality, and 6-month mortality, and the CURB-65 had highest mortality for 1-year mortality. The QSOFA had the highest kappa statistic for in-hospital mortality, the CURB-65 had the highest kappa statistic for 30-day mortality, and the PSI had the highest kappa statistic for 6-month and 1-year mortality. The AUC was highest for the ATS criteria for in-hospital mortality, and was highest for the PSI at the remaining time points. CONCLUSIONS The results of this study show that QSOFA and the PSI are the most reliable severity indices for mortality predictions based on these measures. QSOFA was found, on average, to have the highest accuracy, sensitivity, and NPV. Additionally, PSI was found, on average, to have the highest kappa statistic, specificity, and PPV. The AUC, on average, was best with PSI as the predictor. QSOFA is most capable of making true negative predictions and the PSI is the most capable of making true positive predictions across the four time points

Comparing Outcomes for Community-Acquired Pneumonia Between Females and Males: Results from the University of Louisville Pneumonia Study

Introduction: Male sex is currently considered to be a risk factor for worsened community-acquired pneumonia (CAP) outcomes compared to female sex; hence, female sex equates to a lower score on the Pneumonia Severity Index. There is no recent update on sex-based outcomes of patients with CAP. The objective of this study was to compare the outcomes of CAP between females and males. Methods: This was a secondary analysis of the University of Louisville Pneumonia Study database. It was a prospective population-based cohort study of all hospitalized adults with CAP who were residents of Jefferson County in the city of Louisville, Kentucky. The study included data from June 1, 2014, to May 31, 2016, and data from October 1, 2016, to May 31, 2017. The study population was divided into two groups: females and males. Results: Female patients had a 13% lower mortality at one year compared to males (aHR 1.13 [95% CI 1.05–1.23], P=0.002). There was no significant difference in mortality between the two groups during hospitalization or at 30-day or six-month follow-up. The median time to discharge for both female and male patients hospitalized with CAP was five days (interquartile range [IQR] 3, 9 days). The median time to clinical stability for both female and male patients hospitalized with CAP was two days (IQR 1, 4 days). Conclusion: This study shows that female patients had significantly lower one-year mortality compared to males. There was no significant difference between females and males in time to clinical stability or length of stay. Further investigation is needed to examine whether risk factors associated with female and male sex predict outcomes among hospitalized patients due to CAP

A Software Tool for Automated Upload of Large Clinical Datasets Using REDCap and the CAPO Database

Introduction: Obtaining clinical data from healthcare sources is necessary for conducting clinical research. New technologies now allow for connecting a research database to Electronic Medical Records remotely, allowing the automatic import of clinical research data. In this paper we design and evaluate a REDCap extension to import clinical records from an external health database. Methods: Many hospital EHRs are designed to use secure file transfer protocol (SFTP) repositories for data communication. We develop a REDCap plugin to connect to an external SFTP file repository for the import of clinical record data. We use the CAPO instance of REDCap and a sample set of clinical pneumonia variables for the connection. Results: The plugin allows the input of record data in a much shorter time than traditional data entry in addition to being less error prone. However, the formatting of the data in the SFTP file repository must be exact in order for the import to be successful. This can require setup time on the part of EHR IT staff. Conclusion: Developing a direct connection from EHR to research database can be an effective way to lower the overhead for conducting clinical research. We demonstrate a means to do this using REDCap and SFTP