Category: Nevin Manimala

Med Phys. 2022 Apr 12. doi: 10.1002/mp.15669. Online ahead of print.

ABSTRACT

BACKGROUND: Electrical impedance tomography (EIT) is a non-ionizing imaging technique for real-time imaging of ventilation of patients with respiratory distress. Cross-sectional dynamic images are formed by reconstructing the conductivity distribution from measured voltage data arising from applied alternating currents on electrodes placed circumferentially around the chest. Since the conductivity of lung tissue depends on air content, blood flow, and the presence of pathology, the dynamic images provide regional information about ventilation, pulsatile perfusion, and abnormalities. However, due to the ill-posedness of the inverse conductivity problem, EIT images have coarse spatial resolution. One method of improving the resolution is to include prior information in the reconstruction.

PURPOSE: In this work, we propose a technique in which a statistical prior built from an anatomical atlas is used to post-process EIT reconstructions of human chest data. The effectiveness of the method is demonstrated on data from two patients with cystic fibrosis.

METHODS: A direct reconstruction algorithm known as the D-bar method was used to compute a 2-D reconstruction of the conductivity distribution in the plane of the electrodes. Reconstructions using one step in an iterative (regularized) Newton’s method were also computed for comparison. An anatomical atlas consisting of 1,589 synthetic EIT images computed from X-ray computed tomography (CT) scans of 74 adult male subjects was computed for use as a statistical prior. The resolution of the D-bar images were then improved by maximizing the conditional probability density function of an image that is consistent with the a priori information and the statistical model. A new method to evaluate the accuracy of the EIT images using CT scans of the imaged patient as ground truth is presented. The novel approach is tested on data from two patients with cystic fibrosis.

RESULTS AND CONCLUSIONS: The D-bar images resulted in better structural similarity index measures (SSIM) and multi-scale (MS) SSIM measures for both subjects using the mask or amplitude evaluation approach than the one-step (regularized) Newton’s method. Further improvement was achieved using the Schur complement (SC) approach, with MS-SSIM values of 0.718 and 0.682 using SC evaluated with the mask and amplitude approach, respectively, for Patient 1, and MS-SSIM values of 0.726 and 0.692 using SC evaluated with the mask and amplitude approach, respectively, for Patient 2. The results from applying an anatomical atlas and statistical prior to EIT data from two patients with cystic fibrosis suggest that the spatial resolution of the EIT image can be improved to reveal pathology that may be difficult to discern in the original EIT image. The novel metric of evaluation is consistent with the appearance of improved spatial resolution and provides a new way to evaluate the accuracy of EIT reconstructions when a CT scan is available. This article is protected by copyright. All rights reserved.

PMID:35411573 | DOI:10.1002/mp.15669

Clin Anat. 2022 Apr 11. doi: 10.1002/ca.23884. Online ahead of print.

ABSTRACT

Most guidelines fail to specify patient positioning during central venous catheterization. The objective was to determine the effects of head-down tilt (Trendelenburg position) and head rotation on the internal jugular vein (IJV). A prospective, observational, longitudinal, and descriptive study using healthy adult volunteers, of both sexes, was performed. The change in position and cross-sectional areas (CSA) of the right IJV and common carotid artery (CA) were measured by ultrasonography during Trendelenburg position (TP) (0°, 5°, 10°, and 15°) and contralateral head-rotation (HR) (0°, 45°, and 90°) for a total of 12 positions. The neutral supine position was first, randomizing the other 11 positions, with 5-minute rest intervals in between. Vital signs and symptoms were recorded. A total of 54 volunteers were recruited between the ages of 21 and 32, of which 30 were men. Any degree of TP or HR significantly increased the CSA. The largest area obtained was 1.78cm² with a TP15HR90 which did not have a statistical difference with TP10HR45 1.59cm² . A HR90 tended to displace the IJV medially, overlaying the CA. Any degree of TP or HR will significantly increase CSA or the right IJV. A 5° to 10° TP is recommended when the patient’s condition allows it, with a 45° HR, without significantly displacing the IJV anterior to the CCA. This article is protected by copyright. All rights reserved.

PMID:35411564 | DOI:10.1002/ca.23884

Environ Sci Pollut Res Int. 2022 Apr 11. doi: 10.1007/s11356-022-19896-3. Online ahead of print.

ABSTRACT

At present, the imbalance in regional development and carbon emissions are the two major challenges that China faces in terms of achieving high-quality development. This paper takes regional development differences as the starting point. First, we adopt the improved CRITIC method to measure the comprehensive development level of 30 regions in China and use K-means clustering to divide the 30 regions into five development levels. Second, the structural path analysis for environmental input-output analysis (EIOA-SPA) model is used to quantify the transfer of carbon emissions between sectors in various regions. Finally, a comprehensive analysis is performed based on the development characteristics of each region and the decomposition results of the carbon emission paths. Then, more precise carbon emission reduction strategies are proposed for the development of different regions in China. The results show that first, the development gap between regions in China has improved, and the development of the central and western regions has achieved remarkable results. However, differences between the north and the south and the gap between coastal and inland regions still exist. Second, the direct carbon emissions of regions with different levels of development are mainly derived from high energy-consuming sectors, especially the production and supply of electricity and heat sector. Third, there are certain differences in the indirect carbon emission pathways of regions with different development levels. The transportation, storage, and postal sector in high developed regions have obvious driving effects on carbon emissions. The building sector plays a prominent role in driving carbon emissions in high developed regions and medium-high developed regions. The building sector, nonmetallic mineral products sector, metal smelting sector, and rolled processed product sector in medium developed regions and medium-low developed regions have relatively high carbon emission-stimulating effects. Therefore, it is necessary to adopt differentiated emission reduction strategies for regions with different development levels in China to achieve adequate carbon emission reductions. This effort would further promote the construction of China’s ecological civilization.

PMID:35411515 | DOI:10.1007/s11356-022-19896-3

Environ Sci Pollut Res Int. 2022 Apr 12. doi: 10.1007/s11356-022-19950-0. Online ahead of print.

ABSTRACT

Understanding the factors affecting R&D trends in the energy sector has a key role in overcoming environmental concerns such as combating climate change, as well as other economic and political problems related to energy. Based on such concerns, this study aims to analyze fundamental factors that determine the energy R&D trends of 29 International Energy Agency (IEA) countries. The data set, consisting of annual indicators for the period 1990-2015, is analyzed with the Driscoll-Kraay panel data estimator. Empirical findings for overall sample show that efficiency, import dependency, and the share of renewable energy use are positively related with R&D expenditure in energy sector. CO₂ intensity is found to be statistically insignificant. When countries are grouped considering their energy composition structures, the dynamics of energy R&D expenditures differ between groups. In overall evaluation, our findings illustrate efficiency and dependency to have greater priority compared to environmental dynamics on energy R&D expenditures for IEA countries during the period.

PMID:35411522 | DOI:10.1007/s11356-022-19950-0

Pharm Res. 2022 Apr 11. doi: 10.1007/s11095-022-03199-w. Online ahead of print.

ABSTRACT

PURPOSE: Skin sampling by tape stripping measures the local bioavailability of topical drug products in the stratum corneum (SC). The goal of the current study was to evaluate the impact of different investigators in studies that utilize a tape stripping protocol designed to minimize investigator variability.

METHODS: Two open-label clinical studies compared two lidocaine patches and a diclofenac patch and solution in twelve healthy volunteers. The mass of drug was determined in SC samples collected on tape strips at three time points following product removal in duplicate by two investigators. Investigator results were compared with each other and with results for the diclofenac solution measured by another laboratory using a similar protocol.

RESULTS: For drug mass, the geometric mean ratio comparing two investigators is within the acceptable bioequivalence interval for most measurement times and drug products. Drug uptake into the SC from the diclofenac solution was not statistically different from that determined in another laboratory. The average flux from the SC over the clearance intervals for the four drug products correspond well with flux measurements from in vitro permeation tests.

CONCLUSIONS: Results from different investigators are reproducible within the limitations of measurement variability, which can be managed by increasing volunteer numbers.

PMID:35411510 | DOI:10.1007/s11095-022-03199-w

Behav Res Methods. 2022 Apr 11. doi: 10.3758/s13428-022-01815-6. Online ahead of print.

ABSTRACT

The probability of superiority (PS) has been recommended as a simple-to-interpret effect size for comparing two independent samples-there are several methods for computing the PS for this particular study design. However, educational and psychological interventions increasingly occur in clustered data contexts; and a review of the literature returned only one method for computing the PS in such contexts. In this paper, we propose a method for estimating the PS in clustered data contexts. Specifically, the proposal addresses study designs that compare two groups and group membership is determined at the cluster level. A cluster may be: (i) a group of cases with each case measured once, or (ii) a single case with each case measured multiple times, resulting in longitudinal data. The proposal relies on nonparametric point estimates of the PS coupled with cluster-robust variance estimation, such that the proposed approach should remain adequate regardless of the distribution of the response data. Using Monte Carlo simulation, we show the approach to be unbiased for continuous and binary outcomes, while maintaining adequate frequentist properties. Moreover, our proposal performs better than the single extant method we found in the literature. The proposal is simple to implement in commonplace statistical software and we provide accompanying R code. Hence, it is our hope that the method we present helps applied researchers better estimate group differences when comparing two groups and group membership is determined at the cluster level.

PMID:35411476 | DOI:10.3758/s13428-022-01815-6

Environ Monit Assess. 2022 Apr 11;194(5):356. doi: 10.1007/s10661-022-10002-1.

ABSTRACT

Coastal lagoons are important but sensitive environments, being transitional zones between land and sea. The Khnifiss lagoon is the most important desert wetland in Morocco, but little data have been produced concerning heavy metal geochemistry and enrichments in the sediments. Therefore, 26 surface sediments (15 intertidal and 11 subtidal) and 2 sediment cores were collected in 2016 and analyzed for a selection of heavy metals. The data were processed to assess the degree of contamination and the corresponding potential ecological risk, using several accumulation/enrichment indices, and the singular and multi-metal risk indices. Mean concentrations in the bottom layers of the two cores, dating from a pre-industrial age according to geochronological analysis, were used as the local geochemical background. The resulting values were on the whole lower than those reported for other areas of the northeastern coast of Morocco. Multivariate statistics were also applied to better understand relationships among variables (metals and other geochemical parameters) and to reveal similarities among sample groups. The results showed that, although the lagoon is not yet affected by significant anthropogenic influences, small enrichments can be recognized, especially for Ni and Cd. The cause may be related to the proximity to the main national highway, the vehicles and machinery used in the saltworks located in the area, and the small harbors used principally for fishing. In addition, industrial emissions from the Atlantic coast of Morocco and adjacent countries can be reasonably attributed as additional contributors to the enrichments. In terms of potential ecological risk, Cd shows the greatest impact compared to the other metals investigated.

PMID:35411468 | DOI:10.1007/s10661-022-10002-1

Surg Endosc. 2022 Apr 11. doi: 10.1007/s00464-022-09210-0. Online ahead of print.

ABSTRACT

BACKGROUND: Esophageal cancer and gastric cancer are two important causes of upper GI malignancies. Literature has shown that minimally invasive esophagectomies (MIE) and gastrectomies (MIG), have shorter length of stay and fewer complications. However, limited literature exists about the association between race and access to MIE and MIG. This study aims to identify the racial disparities in the different approaches to esophagectomy and gastrectomy. We further evaluate the relationship between the race and postoperative complications.

METHODS: This IRB-approved retrospective study utilized data from the American College of Surgeons National Quality Improvement Program. All recorded cases of MIE, MIG, open gastrectomy, and esophagectomy between 2012 and 2019 were isolated. Propensity score matching and univariate analysis was performed to assess the independent effect of black self-identified race on access and outcomes. p < 0.05 was required to achieve statistical significance.

RESULTS: 7891 cases of esophagectomy and 5,132 cases of gastrectomy cases were identified. Using Propensity and logistic regression, we identified that black self-reported race is an independent predictor of open approach to gastrectomy (OR 1.6871943, 95% CI 1.431464-1.989829, p < 0.001). Black self-reported race was not predictive of operative approach among esophagectomy patients (OR 0.7942576, 95% CI 0.5698645-1.124228, p = 0.183). In contrast, black self-reported is an independent predictor of postoperative complications among esophagectomy patients only. Esophagectomy patients of black self-reported race were more likely to experience any complication (OR 1.4373437, 95% CI 1.1129239-1.8557096, p = 0.00537), severe complications (OR 1.3818966, 95% CI 1.0653087-1.7888454, p = 0.0144), and death (OR 2.00779762, 95% CI 1.08034921-3.56117535, p = 0.0211) within 30 days of their surgeries.

CONCLUSION: Our analysis revealed a significant racial disparity in access to MIG and a higher incidence of post-operative complications amongst esophagectomy patients. Minimally invasive techniques are underutilized in racial minorities. The findings herein warrant further investigation to eliminate barriers and disparities.

PMID:35411463 | DOI:10.1007/s00464-022-09210-0

Support Care Cancer. 2022 Apr 11. doi: 10.1007/s00520-022-07005-6. Online ahead of print.

ABSTRACT

BACKGROUND AND AIM: Many pieces of literature have evaluated the predictive value of pre-existing lung interstitial changes for immunotherapy-related pneumonia in patients with non-small cell lung cancer (NSCLC), but the results of studies are still controversial. The purpose of this article is to explore whether pre-existing lung interstitial changes can predict the occurrence of immunotherapy-related pneumonia.

METHODS: PubMed, Web of Science, and Embase were used to search for relevant documents. Two investigators respectively carried out literature screening, quality evaluation, and data extraction strictly according to the inclusion criteria. Odds ratios (ORs) and the corresponding 95% CIs were applied to assess the predictive value of interstitial lung disease (ILD), interstitial lung abnormalities (ILA), and radiation pneumonitis (RP). Stata 12.0 software was used for the statistical analysis of data.

RESULTS: Seventeen studies involving 2758 patients were included in the final analysis. NSCLC patients with pulmonary interstitial changes were more likely to develop immune-related pneumonia after immunotherapy (OR = 3.68, 95% CI: 2.49-5.44). Subgroup analysis revealed that ILD (OR = 3.59, 95% CI: 2.22-5.82), RP (OR = 3.63, 95% CI: 1.80-7.30), and ILA (OR = 6.64, 95% CI: 1.78-24.8) were all predictors of immune-related pneumonia. As the preliminary screening of other risk factors, gender, neutrophilic lymphocyte ratio (NLR), actual eosinophil count (AEC), and drug type may have potential predictive value for immunotherapy-related pneumonia. There was no significant statistical heterogeneity and publication bias in our study. Further research is needed to update and validate our results.

CONCLUSION: Pulmonary interstitial changes can be considered as a predictive factor of immune-related pneumonia after immunotherapy in NSCLC patients.

PMID:35411466 | DOI:10.1007/s00520-022-07005-6

Ann Hematol. 2022 Apr 11. doi: 10.1007/s00277-022-04799-7. Online ahead of print.

NO ABSTRACT

PMID:35411439 | DOI:10.1007/s00277-022-04799-7