Piecewise Linear Regression Analysis Research Articles

Prognostic value of geriatric nutritional risk index in patients with stable coronary artery disease undergoing percutaneous coronary intervention

BackgroundMalnutrition increases the risk of poor prognosis in patients with cardiovascular disease, and our current research was designed to assess the predictive performance of the Geriatric Nutrition Risk Index (GNRI) for the occurrence of poor prognosis after percutaneous coronary intervention (PCI) in patients with stable coronary artery disease (SCAD) and to explore possible thresholds for nutritional intervention.MethodsThis study retrospectively enrolled newly diagnosed SCAD patients treated with elective PCI from 2014 to 2017 at Shinonoi General Hospital, with all-cause death as the main follow-up endpoint. Cox regression analysis and restricted cubic spline (RCS) regression analysis were used to explore the association of GNRI with all-cause death risk and its shape. Receiver operating characteristic curve (ROC) analysis and piecewise linear regression analysis were used to evaluate the predictive performance of GNRI level at admission on all-cause death in SCAD patients after PCI and to explore possible nutritional intervention threshold points.ResultsThe incidence of all-cause death was 40.47/1000 person-years after a mean follow-up of 2.18 years for 204 subjects. Kaplan-Meier curves revealed that subjects at risk of malnutrition had a higher all-cause death risk. In multivariate Cox regression analysis, each unit increase in GNRI reduced the all-cause death risk by 14% (HR 0.86, 95% CI 0.77, 0.95), and subjects in the GNRI > 98 group had a significantly lower risk of death compared to those in the GNRI < 98 group (HR 0.04, 95% CI 0.00, 0.89). ROC analysis showed that the baseline GNRI had a very high predictive performance for all-cause death (AUC = 0.8844), and the predictive threshold was 98.62; additionally, in the RCS regression analysis and piecewise linear regression analysis we found that the threshold point for the GNRI-related all-cause death risk was 98.28 and the risk will be significantly reduced when the subjects' baseline GNRI was greater than 98.28.ConclusionsGNRI level at admission was an independent predictor of all-cause death in SCAD patients after PCI, and GNRI equal to 98.28 may be a useful threshold for nutritional intervention in SCAD patients treated with PCI.

A Consideration of Whole-Life Carbon Emissions by Indiana Manufacturers in Efforts to Gauge Lifecycle Sustainability Records in the Multinational Automobile Industry

Purpose: The Ricardo Report (2020) recommends a holistic analysis of the effects of the global auto industry on sustainability by assessing the impacts of automobiles on the environment throughout their lifecycle. Much of the literature on sustainability in the transportation sector focuses on vehicle exhaust emissions and their contribution to urban smog, and there has been little consideration of emissions produced during the automobile manufacturing process itself. &#x0D; Materials and Methods: This study builds on the lifecycle emissions approach recommended by the Ricardo Report. Specifically, data on the pounds of pollution emitted was collected from the Toxic Release Inventory report of major multinational automobile producers and analyzed via piecewise linear regression analyses to provide insight about the pollution emitted during a vehicle’s production. &#x0D; Findings: The findings in this study will fill a gap in Ricardo’s “birth to grave” proposal to quantify whole-life carbon emissions in the automobile sector.&#x0D; Unique Contribution to Theory, Practice and Policy: As sustainability efforts within the automotive market continues to evolve, it is important to analyze automobile whole-life carbon emissions rather than just what is emitted from the tailpipe, and this study fills a gap in the Ricardo Report by providing data related to the rates of pollution emitted during the manufacture of vehicles at multinational automobile factories in America.

Abstract 7029: Trajectory of DNA methylation in blood up to 18 years prior to lung cancer diagnosis

Abstract Purpose: Lung cancer (LC) has the highest mortality rate in South Korea. As prediction and early detection of lung cancer is pivotal to enhance survival rates, we attempted to investigate the trajectory of DNA methylation (DNAm) several years prior to lung cancer diagnosis by using prediagnostic blood samples. Methods: From National Cancer Center Health Examinee Cohort, established in 2003, we selected study participants who became diagnosed with LC several years after health examination, thereby collecting prediagnostic samples from 18 years to 1 year prior to LC diagnosis. Normal controls (n=150) were matched with patients (n=150) by sex, age, and the time of sample collection. Epigenome-wide DNAm data were obtained by using Infinium Human MethylationEPIC v2.0 Beadchip. We assumed non-linear relationship between DNAm changes and the time-to-diagnosis and estimated an optimal threshold point of non-linear relationship with a piecewise linear regression analysis at each CpG sites (CpGs). We used the ratio of M-values of patients and matched controls to establish the non-linear model composed of two linear models with a threshold point where the slope changes. Then, we performed functional enrichment analysis by each year prior to LC diagnosis using ReactomePA. Results: We identified threshold models with a threshold point where the slope changes from zero (from 18 years prior to LC up to the threshold point) to positive or negative (from threshold point to the point of LC diagnosis), which we termed “flat-to-change model”. Out of 790,048 CpGs, we identified a total of 7214 CpGs showing the “flat-to-change model”, of which 944, 789, 480, 413, 687, 542, 516, 1140, 315, 284, 327, 432, 83, 95, 74, 32, and 23 CpGs were found prior to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, and 17 years before LC diagnosis, respectively. Functional enrichment analysis showed that various pathways were associated at different time point berfore LC diagnosis. CpGs of which DNAm was changed two years before LC diagnosis were associated with telomerase extension by telomerase involving ANKRD28/TERT/TERF2/PPP6R3/WRAP53. Transcriptional regulation by TP53 was associated with DNAm changes before both 5 and 14 years of LC diagnosis via POLR2A. Conclusions: We identified the trajectories of DNA methylation up to 18 years prior to LC diagnosis, and found that a greater number of CpG sites showed DNAm changes adjacent to the time point of LC diagnosis. CpG sites associated with specific time point before LC diagnosis may elucidate the mechanisms of tumorigenesis and also have potential for LC prediction markers. Citation Format: Yoon-Jung Choi, Ki-Jae Hong, Yeon-Su Lee, Woo Jin Kim, Yeol Kim, Sun Ha Jee, Jeongseon Kim. Trajectory of DNA methylation in blood up to 18 years prior to lung cancer diagnosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7029.

Is Attention-Deficit/Hyperactivity Disorder (ADHD) a Dimension or a Category? What Does the Relationship Between ADHD Traits and Psychosocial Quality of Life Tell Us?

Objective: The question of whether attention-deficit/hyperactivity disorder (ADHD) is a discrete category or a continuous dimension remains clinically relevant. We report the first examination of this question from the viewpoint of the relationship between ADHD traits and psychosocial quality of life (QoL), and whether the level of QoL declines markedly around a certain high ADHD trait range suggestive of a categorical boundary. Methods: Parents/caregivers of 1,967 schoolchildren aged 6 to 11 from the general population completed the Pediatric Quality of Life Inventory and the ADHD-Rating Scale IV. Piecewise linear and non-linear regression analyses were performed. Results: No evidence for a non-linear association or an abrupt change in the rate of decrease in QoL was observed in the high end of the ADHD traits continuum. Instead, the relationship was consistent with linearity. Conclusion: Psychosocial QoL gradually declines in a linear manner as ADHD trait levels increase providing further support for a dimensional model.

Association between fasting stress hyperglycemia ratio and contrast-induced acute kidney injury in coronary angiography patients: a cross-sectional study.

Stress hyperglycemia ratio (SHR), an emerging indicator of critical illness, exhibits a significant association with adverse cardiovascular outcomes. The primary aim of this research endeavor is to evaluate the association between fasting SHR and contrast-induced acute kidney injury (CI-AKI). This cross-sectional study comprised 3,137 patients who underwent coronary angiography (CAG) or percutaneous coronary intervention (PCI). The calculation of fasting SHR involved dividing the admission fasting blood glucose by the estimated mean glucose obtained from glycosylated hemoglobin. CI-AKI was assessed based on elevated serum creatinine (Scr) levels. To investigate the relationship between fasting SHR and the proportion of SCr elevation, piecewise linear regression analysis was conducted. Modified Poisson's regression analysis was implemented to evaluate the correlation between fasting SHR and CI-AKI. Subgroup analysis and sensitivity analysis were conducted to explore result stability. Among the total population, 482 (15.4%) patients experienced CI-AKI. Piecewise linear regression analysis revealed significant associations between the proportion of SCr elevation and fasting SHR on both sides (≤ 0.8 and > 0.8) [β = -12.651, 95% CI (-23.281 to -2.022), P = 0.020; β = 8.274, 95% CI (4.176 to 12.372), P < 0.001]. The Modified Poisson's regression analysis demonstrated a statistically significant correlation between both the lowest and highest levels of fasting SHR and an increased incidence of CI-AKI [(SHR < 0.7 vs. 0.7 ≤ SHR < 0.9) β = 1.828, 95% CI (1.345 to 2.486), P < 0.001; (SHR ≥ 1.3 vs. 0.7 ≤ SHR < 0.9) β = 2.896, 95% CI (2.087 to 4.019), P < 0.001], which was further validated through subgroup and sensitivity analyses. In populations undergoing CAG or PCI, both lowest and highest levels of fasting SHR were significantly associated with an increased occurrence of CI-AKI.

Establishment and comparison of piecewise linear regression models to measure thyroid volume by 2D and 3D ultrasound.

Compared thyroid volumes measured by 2-D and 3-D US with those of resected specimens and proposed new models to improve measurement accuracy. This study included 80 patients who underwent total thyroidectomy. One 2D_model and one 3D_model were developed using piecewise linear regression analysis. The accuracy of these models was compared using an ellipsoid model (2-D_US value × 0.5), 3-D_US value, and Ying's model [1.76 + (2-D_US value × 0.38)]. The new 2D_model was: V=2.66 + (0.71 * X1) - (1.51 * X2). In this model, if 2-D_US value <= 228.39, X1 = 2-D_US value and X2 = 0; otherwise, X1 = 2-D_US value and X2 = 2-D_US value - 228.39. The 3D_model was: V= 2.90 + (1.08 * X1) + (2.43 * X2). In this model, if 3-D_US value <= 102.06, X1 = 3-D_US value and X2 = 0; otherwise, X1 = 3-D_US value and X2 = 3-D_US value - 102.06. The accuracy of the new models was higher than that of the 3-D_US value, the ellipsoid model, and Ying's model (P<0.05). The models established are more accurate than the traditional ones and can accurately measure thyroid volume.

Consumer Wearables Define a Normative Recovery Trajectory Following the Modified Nuss Procedure

IntroductionThe modified Nuss procedure is an elective procedure associated with a lengthy recovery, uncontrolled pain, and risk of infrequent, yet life-threatening complications. The absence of objective measures of normative postoperative recovery creates uncertainty about the postdischarge period, which remains highly dependent on the patients' and their caregivers’ expectations and management of recovery. We aimed to describe an objective-normative, physical activity recovery trajectory after the modified Nuss procedure, using step counts from the Fitbit. MethodsThis observational study enrolled children ≤18 y with pectus excavatum who underwent the modified Nuss procedure from 2021 to 2022. The Fitbit was worn for 21 postoperative days. Postdischarge outcomes and health-care utilization were evaluated. For patients without postoperative complications, piecewise linear regression analysis was conducted to generate a normative recovery trajectory model of daily step counts. ResultsOf 80 patients enrolled, 66 (86%) met eligibility criteria (mean age, 15.1 ± 1.3 y; 89.4% male, 62.1% non-Hispanic White). The mean number of telephone and electronic message encounters regarding concerns with the patient's recovery within 30 d postoperatively was 2.1 (standard deviation = 2.7). Ten patients (15.2%) returned to the emergency department (ED) within the 30-d postoperative period. Seven patients (10.6%) presented to the ED one time, and three patients (4.5%) presented to the ED twice. Thirty-day readmission rate was four patients (6.0%). Piecewise regression model showed that patients without complications steadily increased their daily step count on each postoperative day and plateaued on day 18. ConclusionsWe have developed a normative recovery trajectory following the modified Nuss procedure using step count data collected by a consumer wearable device. This offers the potential to inform preoperative patient expectations and reduce avoidable health-care utilization through informed preoperative counseling, thus laying the ground work for the use of consumer wearable devices as a postdischarge remote monitoring tool.

Effect of frailty status on mortality risk among Chinese community-dwelling older adults: a prospective cohort study

BackgroundFrailty is associated with mortality among older adults. We aimed to determine the appropriate time and frailty index (FI) threshold for frailty intervention in Chinese community-dwelling older adults.MethodsIn this prospective cohort study, we used data from the 2011 wave of the Chinese Longitudinal Healthy Longevity Study. Follow-up was performed for seven years from baseline. Using the FI to evaluate frailty and define frailty status, we explored the best time point and FI score for frailty intervention, by comparing the relationships of FI and frailty status with mortality.ResultsFrom 2011 to 2018, 8642 participants were included and followed-up. A total of 4458 participants died during the study period. After adjusting for variables such as age, sex, marital status, education level, and living conditions, the hazard ratio (HR) of mortality risk based on the FI at baseline was 37.484 (95% confidence interval [CI]: 30.217–46.498; P < 0.001); female sex, living in the city, being married, and living with spouse were found to be protective factors, whereas ageing was a risk factor for frailty. The mortality risk was higher in pre-frail than in frail participants (HR: 3.588, 95% CI: 3.212–4.009, P < 0.001). Piecewise linear regression analysis revealed an FI score threshold of 0.5. When the FI score was > 0.5, the HR of mortality based on the FI was 15.758 (95% CI: 3.656–67.924; P < 0.001); when the FI score was ≤ 0.5, the HR of mortality based on the FI was 48.944 (95% CI: 36.162–66.244; P < 0.001).ConclusionUsing FI as a continuous variable to predict death is more accurate than frailty status. The advancement of early interventions for mortality risk reduction is more beneficial in pre-frail than in frail patients, and an FI score of 0.5 was found to be the threshold for mortality prediction using the FI.

Association of systemic immune inflammatory index with all-cause and cause-specific mortality in hypertensive individuals: Results from NHANES.

The relationship between the systemic immune inflammatory index (SII) and the prognosis of hypertensive patients is unclear. This study aims to explore the association of SII with all-cause and cause-specific mortality in patients with hypertension. This study included 8524 adults with hypertension from the National Health and Nutritional Examination Surveys (NHANES) 2011-2018, and followed for survival through December 31, 2019. Cox proportional hazards models were used to investigate the associations between SII and mortality from all causes, cardiovascular disease (CVD), and cancer. Restricted cubic spline, piecewise linear regression, subgroup and sensitivity analyses were also used. During a median follow-up of 4.58 years, 872 all-cause deaths occurred. After adjusting for covariates, higher SII was significantly associated with an elevated risk of CVD mortality. There was a 102% increased risk of CVD mortality per one-unit increment in natural log-transformed SII (lnSII) (P < 0.001). Consistent results were also observed when SII was examined as categorical variable (quartiles). The associations of SII with all-cause and cancer mortality were detected as U-shaped with threshold values of 5.97 and 6.18 for lnSII respectively. Below thresholds, higher SII was significantly associated with lower all-cause mortality (HR=0.79, 95%CI=0.64-0.97) and cancer mortality (HR=0.73, 95%CI=0.53-1.00). Above thresholds, SII was significantly positive associated with all-cause mortality (HR=1.93, 95%CI=1.55-2.40) and cancer mortality (HR=1.93, 95%CI=1.22-3.05). The results were robust in subgroup and sensitivity analyses. Higher SII (either as a continuous or categorical variable) were significantly associated with a higher risk of CVD mortality. The U-shaped associations were observed between SII and all-cause and cancer mortality.

Association between the uric acid to high density lipoprotein cholesterol ratio and alanine transaminase in Chinese short stature children and adolescents: A cross-sectional study.

Uric acid to high-density lipoprotein cholesterol ratio (UHR), the ratio of uric acid to high-density lipoprotein cholesterol, is a newly proposed marker of metabolic abnormalities. There are few previous studies directly investigating the relationship between UHR and alanine aminotransferase (ALT), especially in short stature populations, however, short stature children and adolescents are more likely to have metabolic disorders. This research aimed to investigate the relationship between the UHR and ALT in children and adolescents with short stature. In this cross-sectional analysis, the clinical data of 1,510 children with height below -2 SD who were evaluated at the Department of Endocrinology, Affiliated Hospital of Jining Medical University from 1 March 2013 to 31 December 2021, were selected. Anthropometric and biochemical indicators were measured. The relationship between UHR and ALT was analysed. The univariate analysis results showed that UHR was positively associated with ALT (β = 0.43, P < 0.0001). Furthermore, after adjusting for possible confounding factors, a non-linear relationship was detected between UHR and ALT through smooth curve fitting, and the inflection point of UHR was 10.93% after multivariate piecewise linear regression analysis. ALT increased with UHR elevation when the UHR was greater than 10.93% (β = 0.69, 95% CI 0.39, 0.98; P < 0.0001). However, we did not observe a significant relationship when the UHR was less than 10.93% (P = 0.9229). Our study demonstrated that in Chinese children and adolescents with short stature, UHR may be associated with the regulation of ALT levels, and this relationship merits further investigation.

Residual flexural tensile strength of normal-weight and lightweight steel fibre-reinforced concrete at elevated temperatures

In this study, the residual flexural tensile strength (fR,j) of steel fibre reinforced concrete (SFRC) at elevated temperature was investigated through a detailed test program. Sixty pre-notched SFRC prism specimens, cast with both normal-weight and lightweight concrete with different fibre contents, were heated inside a furnace to temperature ranging from 200 °C to 800 °C. The uniformly heated specimens were then subject to three-point bending using a carefully configurated test setup, to evaluate the residual flexural tensile strengths at elevated temperatures. The specimens were also tested at ambient temperature for benchmark comparison. A drop in both the residual flexural tensile strengths and the stiffness of SFRC was observed with the increase of temperature. The flexural tensile strength retention plotted against the elevated temperature exhibited a bilinear relationship. Based on the experimental results, a piecewise linear regression analysis was carried out to propose empirical equations to predict the residual flexural tensile strength of SFRC at elevated temperatures. The proposed equations were able to predict the strength retention factors with an average accuracy of around 98 % and a standard deviation of 18 % on average. The results from this study form the basis for predicting the behaviour of SFRC structural members under fire conditions.

Association between serum Klotho concentration and all-cause and cardiovascular mortality among American individuals with hypertension.

Evidence indicates that serum Klotho concentration is associated with mortality in patients with chronic kidney disease (CKD). However, evidence on this association among people with hypertension is scarce. Therefore, we aimed to examine the association between serum Klotho concentration and all-cause and cardiovascular mortality in American patients with hypertension. We included 6,778 participants with hypertension from the National Health and Nutrition Examination Survey (NHANES) 2007-2014. A Cox proportional hazard model was used to compute the hazard ratios (HRs) and 95% confidence intervals (CIs). The correlation between serum Klotho concentration and mortality was determined using restricted cubic spline and piecewise linear regression analyses. During 36,714 person-years of follow-up, 575 deaths were documented. Lower serum Klotho concentration was associated with increased all-cause mortality, but not cardiovascular mortality after multivariate adjustment. According to spline analysis, the correlation between serum Klotho concentration and all-cause mortality was non-linear (P < 0.001), and the threshold value was 574 pg/mL. The HR below the threshold point was 0.79 (95% CI: 0.67-0.93); no significant difference was found above the threshold point. Higher serum Klotho concentration was associated with lower all-cause mortality, but not cardiovascular mortality in patients with hypertension with or without chronic renal impairment.

U-shaped association between body mass index and ejection fraction in intensive care unit patients with heart failure.

There are limited data about the relationship between body mass index (BMI) and left ventricular ejection fraction (EF) in patients with heart failure (HF). The study aims to assess the correlation between BMI and left ventricular EF under HF conditions. We derived the data from the Dryad Digital Repository for analysis, and the information of the original patients was obtained from the MIMIC-III database by the data uploader. We performed smooth curve and two piecewise linear regression analyses to evaluate the association between BMI and EF in HF patients. A total of 962 participants were included in this study, with age of 73.7±13.5years, and 475 participants were male (49.4%). The results of the smooth curve supported a U-shaped relationship between BMI and EF, and the inflection point was found to be a BMI of 23.3kg/m2 in these HF patients. After adjusting for potential confounders, we found that EF decreased with increasing BMI up to the inflection point (β=-0.7, 95% CI -1.3 to -0.1, P=0.028), whereas beyond the turning point, the relationship between EF and BMI showed a positive correlation (β=0.2, 95% CI 0.1-0.3 P<0.001). Importantly, ischaemic heart disease (interaction P=0.0499) and hyperlipidaemia (interaction P=0.0162) affected the association between BMI and EF in the lower BMI group (BMI<23.3kg/m2 ), although only diabetes mellitus (interaction P=0.0255) altered the association between BMI and EF in the higher BMI group (BMI≥23.3kg/m2 ). In addition to higher BMI, we also found that lower BMI is related to higher EF in intensive care unit patients with HF, supporting a U-shaped association between BMI and EF.

The relationship between hemoglobin and triglycerides in moyamoya disease: A cross-sectional study.

Hemoglobin (Hb) and lipid metabolism are critical in the pathophysiology of moyamoya disease (MMD), and Hb and triglycerides (TGs) both play roles in the development of cerebrovascular illness. However, there is little evidence of a link between Hb and TGs in patients with MMD. This study aimed to determine the association between Hb and TGs in patients who had recently been diagnosed with MMD. From March 2013 to December 2018, 337 patients clinically diagnosed with MMD were admitted to our hospital. Among these, 235 were selected for analysis in this retrospective, cross-sectional study. Each patient's clinical features were documented. For analysis, we used univariate analysis, smoothed-curve fitting, and multivariable, piecewise linear regression. Overall, the mean±standard deviation patient age was 48.14 ± 11.24 years, 44.68% were men, and the mean Hb concentration was 135.72 ± 18.99 g/L. After controlling for relevant confounders, smoothed-curve fitting revealed a nonlinear association between the Hb and TG concentrations (P = 0.0448). When the Hb concentration was below 141 g/L, multivariate piecewise linear regression analysis revealed a significant association between the Hb and TG concentrations [β: 0.01, 95% confidence interval (CI): 0.00, 0.01; P = 0.0182], although the association disappeared above this threshold (β:−0.00, 95% CI:−0.01, 0.01; P = 0.4429). In individuals newly diagnosed with MMD, there is a significant correlation between Hb and TGs, which may be connected to MMD pathogenesis.

Vaccine Coverage Associated With Ending a Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Wave: A Retrospective Longitudinal Analysis.

ABSTRACTBackgroundTwo SARS-CoV-2 waves in Israel ended while a substantial number of individuals remained unvaccinated or partially vaccinated. The indirect protective effect of the first BNT162b2 vaccination campaign in Israel was evaluated between 22 December 2020 and 18 May 2021.MethodsThe daily percentage of new PCR-confirmed SARS-CoV-2 cases among unvaccinated individuals was analyzed for trends. Major shifts were identified using piecewise linear regression analysis. At these shifts, the percentage of naturally vaccinated (past SARS-CoV-2 cases) and the percentage of actively vaccinated (by inoculation) individuals were weighted and summed to determine the percentage of natural and active vaccination (NAV).ResultsA first decline among unvaccinated individuals occurred during a lockdown period, when the percentage of NAV was 8.16%. The major decline occurred after the end of the lockdown when the percentage of NAV reached 52.05%. SARS-CoV-2 cases ultimately declined among unvaccinated individuals when the percentage of NAV reached 63.55%. During the study period, the Alpha variant was prevalent and the use of non-pharmaceutical intervention, including social distancing, existed to varying degrees.ConclusionsThe vaccination campaign played a major role in the decline of SARS-CoV-2 infection among unvaccinated individuals, leading to the end of the first 2021 SARS-CoV-2 wave (alpha variant) in Israel. The infection of unvaccinated individuals stopped when two thirds of the population were naturally or actively vaccinated. Any change in characteristics of the virus or the population can lead to a new outbreak.

Impact of local mask mandates upon COVID-19 case rates in Oklahoma

Use of face coverings has been shown to reduce transmission of SARS-CoV-2. Despite encouragements from the CDC and other public health entities, resistance to usage of masks remains, forcing government entities to create mandates to compel use. The state of Oklahoma did not create a state-wide mask mandate, but numerous municipalities within the state did. This study compares case rates in communities with mandates to those without mandates, at the same time and in the same state (thus keeping other mitigation approaches similar). Diagnosed cases of COVID-19 were extracted from the Oklahoma State Department of Health reportable disease database. Daily case rates were established based upon listed city of residence. The daily case rate difference between each locality with a mask mandate were compared to rates for the portions of the state without a mandate. All differences were then set to a d0 point of reference (date of mandate implementation). Piecewise linear regression analysis of the difference in SARS-CoV-2 infection rates between mandated and non-mandated populations before and after adoption of mask mandates was then done. Prior to adopting mask mandates, those municipalities that eventually adopted mandates had higher transmission rates than the rest of the state, with the mean case rate difference per 100,000 people increasing by 0.32 cases per day (slope of difference = 0.32; 95% CI 0.13 to 0.51). For the post-mandate time period, the differences are decreasing (slope of -0.24; 95% CI -0.32 to -0.15). The pre- and post- mandate slopes differed significantly (p<0.001). The change in slope direction (-0.59; 95% CI -0.80 to -0.37) shows a move toward reconvergence in new case diagnoses between the two populations. Compared to rates in communities without mask mandates, transmission rates of SARS-CoV-2 slowed notably in those communities that adopted a mask mandate. This study suggests that government mandates may play a role in reducing transmission of SARS-CoV-2, and other infectious respiratory conditions.

Examining clustered somatic mutations with SigProfilerClusters.

MotivationClustered mutations are found in the human germline as well as in the genomes of cancer and normal somatic cells. Clustered events can be imprinted by a multitude of mutational processes, and they have been implicated in both cancer evolution and development disorders. Existing tools for identifying clustered mutations have been optimized for a particular subtype of clustered event and, in most cases, relied on a predefined inter-mutational distance (IMD) cutoff combined with a piecewise linear regression analysis.ResultsHere, we present SigProfilerClusters, an automated tool for detecting all types of clustered mutations by calculating a sample-dependent IMD threshold using a simulated background model that takes into account extended sequence context, transcriptional strand asymmetries and regional mutation densities. SigProfilerClusters disentangles all types of clustered events from non-clustered mutations and annotates each clustered event into an established subclass, including the widely used classes of doublet-base substitutions, multi-base substitutions, omikli and kataegis. SigProfilerClusters outputs non-clustered mutations and clustered events using standard data formats as well as provides multiple visualizations for exploring the distributions and patterns of clustered mutations across the genome.Availability and implementationSigProfilerClusters is supported across most operating systems and made freely available at https://github.com/AlexandrovLab/SigProfilerClusters with an extensive documentation located at https://osf.io/qpmzw/wiki/home/.Supplementary information Supplementary data are available at Bioinformatics online.

Association of Hemoglobin Glycation Index With Contrast-Induced Acute Kidney Injury in Patients Undergoing Coronary Angiography: A Retrospective Study.

Background: The hemoglobin glycation index (HGI) quantifies interindividual variation in glycation and is positively associated with cardiovascular diseases. However, the association between HGI and contrast-induced acute kidney injury (CI-AKI) remains unclear. Therefore, this study aimed to assess the association of HGI with CI-AKI. Methods: In this observational study, a total of 3,142 patients undergoing coronary angiography (CAG) or percutaneous coronary intervention (PCI) were included. The HGI was calculated as the difference between the measured glycated hemoglobin (HbA1c) and predicted HbA1c. CI-AKI was defined as an increase of either 25% or 0.5 mg/dl (44.2 μmol/L) in the serum creatinine (SCr) level within 72 h following the exposure to contrast medium. Piecewise linear regression analysis was conducted to testify the association of HGI with the proportion of SCr elevation. Modified Poisson’s regression analysis was performed to determine the association between HGI and CI-AKI. Exploratory analysis was also performed according to the stratification of HbA1c levels. Results: Among 3,142 patients, the average age was 66.9 years and 483 of them (15.4%) suffered CI-AKI. Piecewise linear regression analysis demonstrated the linear association of HGI with the proportion of SCr elevation on both positive and negative sides of HGI [HGI <0: β = −9.537, 95% CI (−12.057 to −7.017), p < 0.001; HGI ≥0: β = 1.655, 95% CI (0.125 to 3.186), p = 0.034]. Modified Poisson’s regression analysis showed that the higher absolute value of HGI was strongly associated with higher incidence of CI-AKI [(<−1.0 vs. −0.2 to 0.2): aRR = 1.897, 95% CI [1.467 to 2.452], p < 0.001 (≥1.0 vs. −0.2 to 0.2): aRR = 1.545, 95% CI (1.171 to 2.037), p = 0.002]. Furthermore, the results in exploratory analysis showed that such association still remained irrespective of HbA1c levels. Conclusion: The higher absolute value of HGI was strongly associated with higher incidence of CI-AKI in patients undergoing CAG and PCI.

Insight into the environmental significance of grain-size fractal and pedogenesis of a typical loess and paleosol sequence

The loess-paleosol sequence contains rich climate change information during formation process. A typical loess-paleosol sequence was selected to analyze the grain-size, magnetic susceptibility and element intensity of samples. Fractal method was used to describe the characteristics of grain-size distribution and evaluate the relationship between fractal dimension and pedogenesis process. Based on the results of the mass balance and soil reconstruction model, the relationship between loess deposition and pedogenesis was studied. Change of unary fractal dimensions was consistent with the changing trend of climate indicators, and average fractal dimensions of paleosol (2.246) was greater than that of loess (2.201). The fractal dimension can evaluate the fragmentation degree of particles and magnitude of energy events. Results of piecewise linear regression analysis showed that there were two different fragmentation mechanisms in the process of particle fragmentation. DF1 was close to 3, and the energy dissipation in the process of coarse particles breaking into fine particles was mainly manifested in volume; DF2 was close to 2, and the energy in the process of breaking fine particles into clay particles mainly proceeded along a two-dimensional plane. The volume changes of loess and paleosol were simultaneously affected by pedogenesis, formation pressure and global climate. The mass loss or gain shown by the different size-fraction components and element intensity indicated that the loess deposition and pedogenesis were simultaneous. During the prevailing summer monsoon, strong pedogenesis was dominant and formed paleosol. While the cold-dry climate during the prevailing winter monsoon promoted the loess deposition. The fractal and reconstruction model respectively quantitatively calculated the degree of particle fragmentation and the amount and process of material change during the formation process of loess-paleosol. Their combined application can enrich the theory of soil genesis and help to understand the origin of loess-paleosol sequence and its relationship with climate change.

Relationship between controlled attenuated parameter and magnetic resonance imaging-proton density fat fraction for evaluating hepatic steatosis in patients with NAFLD.

We used cross‐sectional and longitudinal studies to comprehensively compare hepatic steatosis measurements obtained with magnetic resonance imaging–proton density fat fraction (MRI‐PDFF) and controlled attenuated parameter (CAP) in hepatic steatosis in adults with nonalcoholic fatty liver disease (NAFLD). A total of 185 participants with NAFLD and 12 non‐NAFLD controls were recruited. CAP and MRI‐PDFF data were collected at baseline from all participants and from 95 patients included in the longitudinal study after 24 weeks of drug or placebo intervention. Pearson correlation, linear regression, and piecewise linear regression analyses were used to evaluate the relationship between the two modalities. Linear analysis suggested a positive correlation between CAP and MRI‐PDFF (r = 0.577, p < 0.0001); however, piecewise linear regression showed no correlation when CAP was ≥331 dB/m (p = 0.535). In the longitudinal study, both the absolute and relative change measurements were correlated between the two modalities; however, the correlation was stronger for the relative change (relative r = 0.598, absolute r = 0.492; p < 0.0001). Piecewise linear regression analysis revealed no correlation when CAP was reduced by more than 53 dB/m (p = 0.193). Conclusions: We found a correlation between CAP and MRI‐PDFF measurements for grading hepatic steatosis when CAP was <331 dB/m. While the measured absolute change and relative change were correlated, it was stronger for the relative change. These findings have implications for the clinical utility of CAP or MRI‐PDFF in the clinical diagnosis and assessment of NAFLD.