Tag: nevin manimala

Minim Invasive Ther Allied Technol. 2023 Mar 10:1-8. doi: 10.1080/13645706.2023.2186181. Online ahead of print.

ABSTRACT

BACKGROUND: To compare the models obtained with classical statistical methods and machine learning (ML) algorithms to predict postoperative infective complications (PICs) after retrograde intrarenal surgery (RIRS).

MATERIAL AND METHODS: Patients who underwent RIRS between January 2014 and December 2020 were retrospectively screened. Patients who did not develop PICs were classified as Group 1 and patients who developed as Group 2.

RESULTS: Three-hundred and twenty-two patients were included in the study; 279 patients (86.6%) who did not develop PICs were classified as Group 1, and 43 patients (13.3%) who developed PICs were classified as Group 2. In multivariate analysis, the presence of diabetes mellitus, preoperative nephrostomy, and stone density were determined to be factors that significantly predicted the development of PICs. The area under the curve (AUC) of the model obtained by classical Cox regression analysis was 0.785, and the sensitivity and specificity were 74% and 67%, respectively. With the Random Forest, K- Nearest Neighbour, and Logistic Regression methods, the AUC was calculated as 0.956, 0.903, and 0.849, respectively. RF’s sensitivity and specificity were calculated as 87% and 92%, respectively.

CONCLUSION: With ML, more reliable and predictive models can be created than with classical statistical methods.

PMID:36896768 | DOI:10.1080/13645706.2023.2186181

Hum Brain Mapp. 2023 Mar 10. doi: 10.1002/hbm.26257. Online ahead of print.

ABSTRACT

Brain wiring redundancy counteracts aging-related cognitive decline by reserving additional communication channels as a neuroprotective mechanism. Such a mechanism plays a potentially important role in maintaining cognitive function during the early stages of neurodegenerative disorders such as Alzheimer’s disease (AD). AD is characterized by severe cognitive decline and involves a long prodromal stage of mild cognitive impairment (MCI). Since MCI subjects are at high risk of converting to AD, identifying MCI individuals is essential for early intervention. To delineate the redundancy profile during AD progression and enable better MCI diagnosis, we define a metric that reflects redundant disjoint connections between brain regions and extract redundancy features in three high-order brain networks-medial frontal, frontoparietal, and default mode networks-based on dynamic functional connectivity (dFC) captured by resting-state functional magnetic resonance imaging (rs-fMRI). We show that redundancy increases significantly from normal control (NC) to MCI individuals and decreases slightly from MCI to AD individuals. We further demonstrate that statistical features of redundancy are highly discriminative and yield state-of-the-art accuracy of up to 96.8 ± 1.0% in support vector machine (SVM) classification between NC and MCI individuals. This study provides evidence supporting the notion that redundancy serves as a crucial neuroprotective mechanism in MCI.

PMID:36896755 | DOI:10.1002/hbm.26257

Hum Brain Mapp. 2023 Mar 10. doi: 10.1002/hbm.26259. Online ahead of print.

ABSTRACT

Statistical effects of cortical metrics derived from standard T1- and T2-weighted magnetic resonance imaging (MRI) images, such as gray-white matter contrast (GWC), boundary sharpness coefficient (BSC), T1-weighted/T2-weighted ratio (T1w/T2w), and cortical thickness (CT), are often interpreted as representing or being influenced by intracortical myelin content with little empirical evidence to justify these interpretations. We first examined spatial correspondence with more biologically specific microstructural measures, and second compared between-marker age-related trends with the underlying hypothesis that different measures primarily driven by similar changes in myelo- and microstructural underpinnings should be highly related. Cortical MRI markers were derived from MRI images of 127 healthy subjects, aged 18-81, using cortical surfaces that were generated with the CIVET 2.1.0 pipeline. Their gross spatial distributions were compared with gene expression-derived cell-type densities, histology-derived cytoarchitecture, and quantitative R1 maps acquired on a subset of participants. We then compared between-marker age-related trends in their shape, direction, and spatial distribution of the linear age effect. The gross anatomical distributions of cortical MRI markers were, in general, more related to myelin and glial cells than neuronal indicators. Comparing MRI markers, our results revealed generally high overlap in spatial distribution (i.e., group means), but mostly divergent age trajectories in the shape, direction, and spatial distribution of the linear age effect. We conclude that the microstructural properties at the source of spatial distributions of MRI cortical markers can be different from microstructural changes that affect these markers in aging.

PMID:36896711 | DOI:10.1002/hbm.26259

Biometrics. 2023 Mar 10. doi: 10.1111/biom.13853. Online ahead of print.

ABSTRACT

The Dirichlet-multinomial (DM) distribution plays a fundamental role in modern statistical methodology development and application. Recently, the DM distribution and its variants have been used extensively to model multivariate count data generated by high-throughput sequencing technology in omics research due to its ability to accommodate the compositional structure of the data as well as overdispersion. A major limitation of the DM distribution is that it is unable to handle excess zeros typically found in practice which may bias inference. To fill this gap, we propose a novel Bayesian zero-inflated DM model for multivariate compositional count data with excess zeros. We then extend our approach to regression settings and embed sparsity-inducing priors to perform variable selection for high-dimensional covariate spaces. Throughout, modeling decisions are made to boost scalability without sacrificing interpretability or imposing limiting assumptions. Extensive simulations and an application to a human gut microbiome data set are presented to compare the performance of the proposed method to existing approaches. We provide an accompanying R package with a user-friendly vignette to apply our method to other data sets. This article is protected by copyright. All rights reserved.

PMID:36896642 | DOI:10.1111/biom.13853

J Clin Endocrinol Metab. 2023 Mar 10:dgad108. doi: 10.1210/clinem/dgad108. Online ahead of print.

ABSTRACT

CONTEXT: Liver function abnormalities (LFA) have been described in patients with Turner Syndrome (TS). Although a high risk of cirrhosis has been reported, there is a need to assess the severity of liver damage in a large cohort of adult patients with TS.

OBJECTIVE: Evaluate the types of LFA and their respective prevalence, search for their risk factors and evaluate the severity of liver impairment by using a non-invasive fibrosis marker.

DESIGN AND SETTINGS: A monocentric retrospective cross-sectional study.

PATIENTS AND INTERVENTION: Data were collected during a day hospital.

MAIN OUTCOME MEASURES: Liver enzymes (ALT, AST, GGT, ALP), FIB-4 score, liver ultrasound imaging, elastography and liver biopsies, when available.

RESULTS: 264 patients with TS were evaluated at a mean age of 31.15 ± 11.48 years. The overall prevalence of LFA was 42.8%. Its risk factors were age, BMI, insulin resistance and an X isochromosome (Xq). The mean FIB-4 sore of the entire cohort was 0.67 ± 0.41. Less than 10% of patients were at risk of developing fibrosis. Cirrhosis was observed in 2/19 liver biopsies. There was no significant difference in the prevalence of LFA between premenopausal patients with natural cycles and those receiving hormone replacement therapy (HRT) (p = 0.063). A multivariate analysis adjusted for age showed no statistically significant correlation between HRT and abnormal GGT levels (p = 0.12).

CONCLUSION: Patients with TS have a high prevalence of LFA. However, 10% are at high risk of developing fibrosis. The FIB-4 score is useful and should be part of the routine screening strategy. Longitudinal studies and better interactions with hepatologists should improve our knowledge of liver disease in patients with TS.

PMID:36896592 | DOI:10.1210/clinem/dgad108

Ann Med. 2023 Dec;55(1):898-907. doi: 10.1080/07853890.2023.2184859.

ABSTRACT

BACKGROUND: The purpose of this study was to explore the changes in blood cellular and biochemical parameters of rats in a natural environment of low pressure and low oxygen on the plateau.

METHODS: Male Sprague-Dawley rats in two groups were raised in different environments from 4 weeks of age for a period of 24 weeks. They were raised to 28 weeks of age and then transported to the plateau medical laboratory of Qinghai University. Blood cellular and biochemical parameters were measured and the data of the two groups were statistically analyzed.

RESULTS: 1. RBC in the HA group was higher than that in the Control group, but there was no significant difference between the two groups (p > 0.05), Compared with the Control group, HGB, MCV, MCH, MCHC and RDW in the HA group were significantly higher (p < 0.05). 2. Compared with the Control group, WBC, LYMP, EO, LYMP% and EO% in the HA group decreased significantly (p < 0.05), and ANC% increased significantly (p < 0.05). 3. In the platelet index, compared with the Control group, PLT in the HA group was significantly reduced (p < 0.05), PDW, MRV, P-LCR were significantly increased (p < 0.05). 4. In blood biochemical indicators, compared with the Control group, AST, TBIL, IBIL, LDH in the HA group decreased significantly (p < 0.05), CK in the HA group increased significantly (p < 0.05).

CONCLUSIONS: 1. The indexes related to red blood cells, white blood cells, platelets and some biochemical indexes in the blood of rats at high altitude have changed. 2. Under the high altitude environment, the oxygen carrying capacity of SD rats is improved, the resistance to disease may be reduced, the coagulation and hemostasis functions may be affected, and there is a risk of bleeding. The liver function, renal function, heart function and skeletal muscle energy metabolism may be affected. 3. This study can provide an experimental basis for the research on the pathogenesis of high-altitude diseases from the perspective of blood.KEY MESSAGESIn this study, red blood cells, white blood cells, platelets and blood biochemical indicators were included in the real plateau environment to comprehensively analyze the changes of blood cellular and biochemical parameters in rats under the chronic plateau hypobaric hypoxia environment.From the perspective of blood, this study can provide an experimental basis for research on the pathogenesis of high-altitude diseases.Explore the data support of oxygen-carrying capacity, disease resistance and energy metabolism of the body in the natural environment at high altitude.

PMID:36896573 | DOI:10.1080/07853890.2023.2184859

Pediatrics. 2023 Mar 10:e2022056617. doi: 10.1542/peds.2022-056617. Online ahead of print.

ABSTRACT

OBJECTIVE: Home caregivers (eg parents) of pediatric patients with cancer with external central lines (CL) must carefully maintain this device to prevent complications. No guidelines exist to support caregiver skill development, assess CL competency, follow-up after initial CL teaching, and support progress over time. We aimed to achieve >90% caregiver independence with CL care within 1 year through a family-centered quality improvement intervention.

METHODS: Drivers to achieve CL care independence were identified using surveys and interviews of patient or caregivers, a multidisciplinary team with patient or family representatives, and piloting clinic return demonstrations (teach-backs). A family-centered CL care skill-learning curriculum, with a postdischarge teach-back program, was implemented using plan-do-study-act cycles. Patients or caregivers participated until independent with CL flushing. Changes included: language iterations to maximize patient or caregiver engagement, developing standardized tools for home use and for teaching and evaluating caregiver proficiency on the basis of number of nurse prompts required during the teach-back, earlier inpatient training, and clinic redesign to incorporate teach-backs into routine visits. The proportion of eligible patients whose caregiver had achieved independence in CL flushing was the outcome measure. Teach-back program participation was a process measure. Statistical process control charts tracked change over time.

RESULTS: After 6 months of quality improvement intervention, >90% of eligible patients had a caregiver achieve independence with CL care. This was sustained for 30 months postintervention. Eighty-eight percent of patients (n = 181) had a caregiver participate in the teach-back program.

CONCLUSION: A family-centered hands-on teach-back program can lead to caregiver independence in CL care.

PMID:36896569 | DOI:10.1542/peds.2022-056617

Math Biosci Eng. 2023 Jan 13;20(3):5949-5965. doi: 10.3934/mbe.2023257.

ABSTRACT

Utilizing statistical information from the Seventh National Population Census, statistical yearbook and sampling dynamic survey data, this study examines the distribution characteristics of the floating population in Beijing, Tianjin and Hebei Region as well as the growth trend of the floating population in each region. It also makes assessments using floating population concentration and The Moran Index Computing Methods. According to the study, the spatial distribution of the floating population has a clear clustering pattern in Beijing, Tianjin and Hebei region. Beijing, Tianjin and Hebei region’s mobile population growth patterns differ substantially, and the region’s inflow population is mostly made up of migrant inhabitants of domestic provinces and inflow of people from nearby regions. Most of the mobile population resides in Beijing and Tianjin, whereas the outflow of people originates in Hebei province. The diffusion impact and the spatial features of the floating population in the Beijing, Tianjin and Hebei area have a constant, positive association, according to the timeline between 2014 and 2020.

PMID:36896558 | DOI:10.3934/mbe.2023257

Math Biosci Eng. 2023 Jan 12;20(3):5379-5412. doi: 10.3934/mbe.2023249.

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading worldwide for over two years, with millions of reported cases and deaths. The deployment of mathematical modeling in the fight against COVID-19 has recorded tremendous success. However, most of these models target the epidemic phase of the disease. The development of safe and effective vaccines against SARS-CoV-2 brought hope of safe reopening of schools and businesses and return to pre-COVID normalcy, until mutant strains like the Delta and Omicron variants, which are more infectious, emerged. A few months into the pandemic, reports of the possibility of both vaccine- and infection-induced immunity waning emerged, thereby indicating that COVID-19 may be with us for longer than earlier thought. As a result, to better understand the dynamics of COVID-19, it is essential to study the disease with an endemic model. In this regard, we developed and analyzed an endemic model of COVID-19 that incorporates the waning of both vaccine- and infection-induced immunities using distributed delay equations. Our modeling framework assumes that the waning of both immunities occurs gradually over time at the population level. We derived a nonlinear ODE system from the distributed delay model and showed that the model could exhibit either a forward or backward bifurcation depending on the immunity waning rates. Having a backward bifurcation implies that $ R_c < 1 $ is not sufficient to guarantee disease eradication, and that the immunity waning rates are critical factors in eradicating COVID-19. Our numerical simulations show that vaccinating a high percentage of the population with a safe and moderately effective vaccine could help in eradicating COVID-19.

PMID:36896550 | DOI:10.3934/mbe.2023249

Math Biosci Eng. 2023 Jan 11;20(3):5352-5378. doi: 10.3934/mbe.2023248.

ABSTRACT

Penalized Cox regression can efficiently be used for the determination of biomarkers in high-dimensional genomic data related to disease prognosis. However, results of Penalized Cox regression is influenced by the heterogeneity of the samples who have different dependent structure between survival time and covariates from most individuals. These observations are called influential observations or outliers. A robust penalized Cox model (Reweighted Elastic Net-type maximum trimmed partial likelihood estimator, Rwt MTPL-EN) is proposed to improve the prediction accuracy and identify influential observations. A new algorithm AR-Cstep to solve Rwt MTPL-EN model is also proposed. This method has been validated by simulation study and application to glioma microarray expression data. When there were no outliers, the results of Rwt MTPL-EN were close to the Elastic Net (EN). When outliers existed, the results of EN were impacted by outliers. And whenever the censored rate was large or low, the robust Rwt MTPL-EN performed better than EN. and could resist the outliers in both predictors and response. In terms of outliers detection accuracy, Rwt MTPL-EN was much higher than EN. The outliers who “lived too long” made EN perform worse, but were accurately detected by Rwt MTPL-EN. Through the analysis of glioma gene expression data, most of the outliers identified by EN were those “failed too early”, but most of them were not obvious outliers according to risk estimated from omics data or clinical variables. Most of the outliers identified by Rwt MTPL-EN were those who “lived too long”, and most of them were obvious outliers according to risk estimated from omics data or clinical variables. Rwt MTPL-EN can be adopted to detect influential observations in high-dimensional survival data.

PMID:36896549 | DOI:10.3934/mbe.2023248