Tag: statistics

J Magn Reson Imaging. 2021 Sep 12. doi: 10.1002/jmri.27905. Online ahead of print.

ABSTRACT

BACKGROUND: Pseudo-spiral Cartesian sampling with compressed sensing reconstruction has facilitated highly accelerated 4D flow magnetic resonance imaging (MRI) in various cardiovascular structures. However, unlike echo planar imaging (EPI)-accelerated 4D flow MRI, it has not been validated in whole-heart applications.

HYPOTHESIS: Pseudo-spiral 4D flow MRI (PROUD [PROspective Undersampling in multiple Dimensions]) is comparable to EPI in robustness of valvular flow measurements and remains comparable as the undersampling factor is increased and scan time reduced.

STUDY TYPE: Prospective.

POPULATION: Twelve healthy subjects and eight patients with valvular regurgitation.

FIELD STRENGTH/SEQUENCE: 3.0 T; PROUD and EPI 4D flow sequences, 2D flow and balanced steady-state free precession sequences.

ASSESSMENT: Valvular blood flow was quantified using valve tracking. PROUD- and EPI-based measurements of aortic (AV) and pulmonary (PV) flow volumes and left and right ventricular stroke volumes were tested for agreement with 2D MRI-based measurements. PROUD reconstructions with undersampling factors (R) of 9, 14, 28, and 56 were tested for intervalve consistency (per valve, compared to the other valves) and preservation of peak velocities and E/A ratios.

STATISTICAL TESTS: We used repeated measures ANOVA, Bland-Altman, Wilcoxon signed rank, and intraclass correlation coefficients. P < 0.05 was considered statistically significant.

RESULTS: PROUD and EPI intervalve consistencies were not significantly different both in healthy subjects (valve-averaged mean difference [limits of agreement width]: 3.2 ± 0.8 [8.7 ± 1.1] mL/beat for PROUD, 5.5 ± 2.9 [13.7 ± 2.3] mL/beat for EPI, P = 0.07) and in patients with valvular regurgitation (2.3 ± 1.2 [15.3 ± 5.9] mL/beat for PROUD, 0.6 ± 0.6 [19.3 ± 2.9] mL/beat for EPI, P = 0.47). Agreement between EPI and PROUD was higher than between 4D flow (EPI or PROUD) and 2D MRI for forward flow, stroke volumes, and regurgitant volumes. Up to R = 28 in healthy subjects and R = 14 in patients with valvular regurgitation, PROUD intervalve consistency remained comparable to that of EPI. Peak velocities and E/A ratios were preserved up to R = 9.

CONCLUSION: PROUD is comparable to EPI in terms of intervalve consistency and may be used with higher undersampling factors to shorten scan times further.

LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 2.

PMID:34510612 | DOI:10.1002/jmri.27905

Mol Ecol. 2021 Sep 12. doi: 10.1111/mec.16176. Online ahead of print.

ABSTRACT

Whole genome sequencing provides deep insights into the evolutionary history of a species, including patterns of diversity, signals of selection, and historical demography. When applied to closely related taxa with a wealth of background knowledge, population genomics provides a comparative context for interpreting population genetic summary statistics and comparing empirical results with the expectations of population genetic theory. The Galapagos giant tortoises (Chelonoidis spp.), an iconic rapid and recent radiation, offer such an opportunity. Here, we sequenced whole genomes from three individuals of the 12 extant lineages of Galapagos giant tortoise and estimate diversity measures and reconstruct changes in coalescent rate over time. We also compare the number of derived alleles in each lineage to infer how synonymous and non-synonymous mutation accumulation rates correlate with population size and life history traits. Remarkably, we find that patterns of molecular evolution are similar within individuals of the same lineage, but can differ significantly among lineages, reinforcing the evolutionary distinctiveness of the Galapagos giant tortoise species. Notably, differences in mutation accumulation among lineages do not align with simple population genetic predictions, suggesting that the drivers of purifying selection are more complex than is currently appreciated. By integrating results from earlier population genetic and phylogeographic studies with new findings from the analysis of whole genomes, we provide the most in-depth insights to date on the evolution of Galapagos giant tortoises, and identify discrepancies between expectation from population genetic theory and empirical data that warrant further scrutiny.

PMID:34510620 | DOI:10.1111/mec.16176

Phytother Res. 2021 Sep 12. doi: 10.1002/ptr.7280. Online ahead of print.

ABSTRACT

The present study aims to summarize and quantitatively examine the available evidence on the effectiveness of anthocyanin supplementation on liver enzymes among patients with metabolic disorders, by employing a systematic review and meta-analytic approach. Online databases including PubMed/Medline, Scopus, ISI Web of Science, and Cochrane Library were searched up to June 2020 for randomized controlled trials (RCTs) that examined the effect of anthocyanin supplementation on serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) among patients with metabolic disorders. To estimate the overall effect of anthocyanin supplementation, we employed the random-effects model. In total, 12 RCTs were included in the systematic review. Pooled analysis did not show any significant changes in ALT (WMD: -0.92 U/L, 95% CI: -4.19 to 2.35, p = .58; I² = 91.3%) and AST (WMD: -1.22 U/L, 95% CI: -3.43 to 0.99, p = .28; I² = 87.0) concentrations after supplementation with anthocyanin. The dose and duration of supplementation were the potential sources of heterogeneity among most of the trials. However, subgroup analysis showed that the effect is not statistically significant in all subgroups. Overall, in our study, anthocyanin does not have any effect on liver enzyme levels significantly. However, future high-quality studies are still needed to confirm the results.

PMID:34510592 | DOI:10.1002/ptr.7280

Adv Mater. 2021 Sep 12:e2104081. doi: 10.1002/adma.202104081. Online ahead of print.

ABSTRACT

The high brightness, low emittance electron beams achieved in modern X-ray free-electron lasers (XFELs) have enabled powerful X-ray imaging tools, allowing molecular systems to be imaged at picosecond time scales and sub-nanometer length scales. One of the most promising directions for increasing the brightness of XFELs is through the development of novel photocathode materials. Whereas past efforts aimed at discovering photocathode materials have typically employed trial-and-error-based iterative approaches, this work represents the first data-driven screening for high brightness photocathode materials. Through screening over 74 000 semiconducting materials, a vast photocathode dataset is generated, resulting in statistically meaningful insights into the nature of high brightness photocathode materials. This screening results in a diverse list of photocathode materials that exhibit intrinsic emittances that are up to 4x lower than currently used photocathodes. In a second effort, multiobjective screening is employed to identify the family of M₂ O (M = Na, K, Rb) that exhibits photoemission properties that are comparable to the current state-of-the-art photocathode materials, but with superior air stability. This family represents perhaps the first intrinsically bright, visible light photocathode materials that are resistant to reactions with oxygen, allowing for their transport and storage in dry air environments.

PMID:34510594 | DOI:10.1002/adma.202104081

Public Health Nurs. 2021 Sep 12. doi: 10.1111/phn.12969. Online ahead of print.

ABSTRACT

OBJECTIVE: Examine the relationship between breastfeeding practices (breastfeeding status and breastfeeding length) and postpartum depression (PPD) risk, after controlling for significant risk factors for PPD.

DESIGN: A cross-sectional, correlational study design was used. Data was used from a national dataset using a subsample of women (n = 29,682) residing in 26 states in the United States that answered the 2016 Pregnancy Risk Assessment Monitoring System (PRAMS) questionnaire. A secondary analysis was conducted using descriptive and bivariate analyses, and a multiple logistic regression model.

RESULTS: Women currently breastfeeding (AOR = 0.87 CI: 0.79-0.95, p = .001), and women who breastfed for longer periods of time (p = < .002) had a statistically significantly lower PPD risk compared to their counterparts, even after accounting for significant covariates.

CONCLUSIONS: Study findings suggest breastfeeding as a cost efficient and healthy behavior that can decrease a woman’s risk for PPD. Nurses should educate and promote the maternal mental health benefits of breastfeeding in addition to the health benefits for the infant.

PMID:34510526 | DOI:10.1111/phn.12969

J Adv Nurs. 2021 Sep 12. doi: 10.1111/jan.15034. Online ahead of print.

ABSTRACT

AIMS: To verify a hypothesized model of the relationships between compassion fatigue, burnout and compassion satisfaction, as well as their influencing factors and consequences, among emergency nurses.

DESIGN: A descriptive, cross-sectional design.

METHODS: A hypothesized model was proposed on the basis of the current literature. A convenience sample was conducted of nurses working in the emergency departments of six hospitals in Shanghai, China, from July to September 2020. A total of 445 valid data points were collected using various self-designed and well-validated instruments. Descriptive statistics and correlations were computed, and a path analysis was used to assess model fitness and to investigate direct and indirect effects.

RESULTS: The final model reported a desirable fit with significant paths. Compassion satisfaction and compassion fatigue directly and inversely affected burnout, and compassion satisfaction positively influenced compassion fatigue. Perceived social support directly improved compassion satisfaction and protected against compassion fatigue. Compassion satisfaction and compassion fatigue directly affected mental health, and burnout directly influenced physical health. Compassion fatigue, burnout and compassion satisfaction had complicated effects on turnover intention.

CONCLUSION: Emergency nurses’ compassion satisfaction and compassion fatigue may be two coexisting constructs, and both affect burnout. Perceived social support acts as a protector of the three dimensions, and their effects on health status and turnover intention can be significant and complicated.

IMPACT: Emergency nurses may experience high levels of compassion satisfaction and compassion fatigue simultaneously, which can help to explain why compassion fatigue did not directly increase emergency nurses’ turnover intention. The direct effects of compassion fatigue and burnout on emergency nurses’ health status and working engagement were significantly different. Support from significant others, professional psychological intervention and emergency nursing system reforms are required to tackle emergency nurses’ compassion fatigue and burnout and improve their compassion satisfaction.

PMID:34510523 | DOI:10.1111/jan.15034

NPJ Precis Oncol. 2021 Sep 10;5(1):82. doi: 10.1038/s41698-021-00223-x.

ABSTRACT

Immune checkpoint inhibitors have demonstrated significant survival benefits in treating many types of cancers. However, their immune-related adverse events (irAEs) have not been systematically evaluated across cancer types in large-scale real-world populations. To address this gap, we conducted real-world data analyses using nationwide insurance claims data with 85.97 million enrollees across 8 years. We identified a significantly increased risk of developing irAEs among patients receiving immunotherapy agents in all seven cancer types commonly treated with immune checkpoint inhibitors. By six months after treatment initialization, those receiving immunotherapy were 1.50-4.00 times (95% CI, lower bound from 1.15 to 2.16, upper bound from 1.69 to 20.36) more likely to develop irAEs in the first 6 months of treatment, compared to matched chemotherapy or targeted therapy groups, with a total of 92,858 patients. The risk of developing irAEs among patients using nivolumab is higher compared to those using pembrolizumab. These results confirmed the need for clinicians to assess irAEs among cancer patients undergoing immunotherapy as part of management. Our methods are extensible to characterizing the effectiveness and adverse effects of novel treatments in large populations in an efficient and economical fashion.

PMID:34508179 | DOI:10.1038/s41698-021-00223-x

Food Chem. 2021 Aug 31;370:131009. doi: 10.1016/j.foodchem.2021.131009. Online ahead of print.

ABSTRACT

This study examines the ability of fluorescence spectroscopy for monitoring the quality of 70 Moroccan virgin olive oils belonging to three varieties and originating from three regions of Morocco. By applying principal component analysis and factorial discriminant analysis to the emission spectra acquired after excitation wavelengths set at 270, 290, and 430 nm, a clear differentiation between samples according to their storage time was observed. The obtained results were confirmed following the application of four multivariate classification methods: partial least squares regression, principal component regression, support vector machine, and multiple linear regression on the emission spectra. The best prediction model of storage time was obtained by applying partial least squares regression since a coefficient of determination (R²) and a root mean square error of prediction (RMSEP) of 0.98 and 24.85 days were observed, respectively. The prediction of the chemical parameters allowed to obtain excellent validation models with R² ranging between 0.98 and 0.99 for free acidity, peroxide value, chlorophyll level, k₂₃₂, and k₂₇₀.

PMID:34509151 | DOI:10.1016/j.foodchem.2021.131009

Food Chem. 2021 Aug 31;370:131006. doi: 10.1016/j.foodchem.2021.131006. Online ahead of print.

ABSTRACT

The contents and profiles of small molecules in a food can provide information about quality-related properties. Processing methods and deterioration during storage, e.g. from bacterial proliferation and degradation, might also lead to changes in the metabolome, which can be determined by mass spectrometry-based metabolomics. By measuring as many metabolites as possible in differently treated pre-cooked chicken fillets in an untargeted approach, we studied individual and combined effects of vacuum packaging (VP), soluble gas stabilisation (SGS), high pressure processing (HPP), and microwave volumetric heating (MW) on the quality and shelf-life of the finished product. The extensive dataset was processed using an optimised workflow of consecutive software tools with stringent statistical analysis to prevent over-interpretation, which is an inherent risk of metabolomics data. Our results showed the predominant influence of VP on storage quality since SGS, HPP, and MW did not have the potential to extent shelf-life.

PMID:34509144 | DOI:10.1016/j.foodchem.2021.131006

Eur J Oncol Nurs. 2021 Aug 14;54:102014. doi: 10.1016/j.ejon.2021.102014. Online ahead of print.

ABSTRACT

PURPOSE: This study evaluated whether coping strategies (positive reframing, planning, and active coping) and depression mediate the relationship between sense of coherence (SOC) and quality of life (QoL) using a serial multiple mediator model in patients with gynecologic cancer who are undergoing chemotherapy.

METHODS: A sample of 148 participants, with a mean age of 52.17 years (range 20-75) and diagnosed with gynecological cancer (e.g., cervix, ovary and endometrium) was surveyed in a cross-sectional study. Data were collected using a structured self-reporting questionnaire. A serial multiple mediator model was analyzed to explain sequential causality among two mediators (coping strategy and depression) and to investigate the direct and indirect effects of the mediator model in SPSSWIN 26.0 and PROCESS macro program.

RESULTS: The conceptual serial mediation model of SOC, positive reframing, depression, and QoL revealed a significant positive total effect (coefficient c = 13.099, SE = 1.647, p < 0.001). The path through single mediation of positive reframing (Effect = 0.925) and depression (Effect = 5.942) and that through both mediators (Effect = 1.161) were statistically significant. The total indirect effect was also statistically significant (Effect = 8.028). Moreover, the conceptual serial mediation model on SOC, planning, depression, and QoL revealed a significant positive total effect (coefficient c = 13.099, SE = 1.647, p < 0.001). The path through both mediation of planning and depression (Effect = 1.162) and the total indirect effect were statistically significant (Effect = 8.172).

CONCLUSIONS: Helping patients with gynecologic cancer undergoing chemotherapy to strengthen SOC may improve QoL by equipping them with efficient positive reframing or planning strategies to reduce depression.

PMID:34509089 | DOI:10.1016/j.ejon.2021.102014