Tag: nevin manimala

Biol Cybern. 2022 Mar 23. doi: 10.1007/s00422-022-00929-6. Online ahead of print.

ABSTRACT

Seminal work by A. Winfree and J. Guckenheimer showed that a deterministic phase variable can be defined either in terms of Poincaré sections or in terms of the asymptotic (long-time) behaviour of trajectories approaching a stable limit cycle. However, this equivalence between the deterministic notions of phase is broken in the presence of noise. Different notions of phase reduction for a stochastic oscillator can be defined either in terms of mean-return-time sections or as the argument of the slowest decaying complex eigenfunction of the Kolmogorov backwards operator. Although both notions of phase enjoy a solid theoretical foundation, their relationship remains unexplored. Here, we quantitatively compare both notions of stochastic phase. We derive an expression relating both notions of phase and use it to discuss differences (and similarities) between both definitions of stochastic phase for (i) a spiral sink motivated by stochastic models for electroencephalograms, (ii) noisy limit-cycle systems-neuroscience models, and (iii) a stochastic heteroclinic oscillator inspired by a simple motor-control system.

PMID:35320405 | DOI:10.1007/s00422-022-00929-6

Intensive Care Med. 2022 Mar 23. doi: 10.1007/s00134-022-06670-9. Online ahead of print.

NO ABSTRACT

PMID:35320369 | DOI:10.1007/s00134-022-06670-9

Anal Bioanal Chem. 2022 Mar 23. doi: 10.1007/s00216-022-04006-6. Online ahead of print.

ABSTRACT

Schistosomiasis, caused by the human parasite Schistosoma mansoni, is one of the WHO-listed neglected tropical diseases (NTDs), and it has severe impact on morbidity and mortality, especially in Africa. Not only the adult worms but also their eggs are responsible for health problems. Up to 50% of the eggs produced by the female worms are not excreted with the feces but are trapped in the host tissue, such as the liver, where they provoke immune responses and a change in the lipid profile. We built up a database with 372 infection markers found in livers of S. mansoni-infected hamsters, using LC-MS/MS for identification, followed by statistical analysis. Most of them belong to the lipid classes of phosphatidylcholines (PCs), phosphatidylethanolamines (PEs), and triglycerides (TGs). We assigned some of these markers to specific anatomical structures by applying high-resolution MALDI MSI to cryosections of hamster liver and generating ion images based on the marker list from the LC-MS/MS experiments. Furthermore, enrichment and depletion of several markers were visualized.

PMID:35320368 | DOI:10.1007/s00216-022-04006-6

PLoS One. 2022 Mar 23;17(3):e0265733. doi: 10.1371/journal.pone.0265733. eCollection 2022.

ABSTRACT

Dry eye disease (DED) is one of the most common ophthalmological disorders, resulting from several systemic and ocular etiologies including meibomian gland dysfunction (MGD). During the COVID-19 pandemic, medical students are among the high-risk group for DED, mainly due to the increasing use of a visual display terminal (VDT) for online lectures and psychological stress from encountering several changes. Our study aimed to explore the prevalence of DED using the symptom-based definition and potential risk factors in medical students. This is a prospective cross-sectional study that included medical students at Chiang Mai University between November 2020 and January 2021. All participants were assessed using the Ocular Surface Disease Index (OSDI) questionnaire, the Thai version of the 10-Item Perceived Stress Scale-10 (T-PSS-10), the LipiView® II interferometer, and an interview for other possible risk factors. Overall, 528 participants were included in the study; half of the participants were female. The prevalence of DED was 70.8%. In the univariate analysis, female sex, contact lens wear, and T-PSS-10 stress scores were significantly higher in the DED group (P = 0.002, 0.002, and <0.001, respectively). Moreover, participants with severe DED were likely to have higher meibomian gland tortuosity but not statistically significant. In the multivariate analysis, contact lens use and T-PSS-10 score were significant risk factors associated with the severity of DED. In conclusions, the prevalence of DED in medical students was as high as 70.8%. Contact lens use and psychological stress evaluated using the T-PSS-10 questionnaire had a significant correlation with a risk of DED. Female gender and duration of VDT use were also associated. Most of the risk factors were modifiable and may be used as initial management in patients with DED.

PMID:35320310 | DOI:10.1371/journal.pone.0265733

PLoS One. 2022 Mar 23;17(3):e0265875. doi: 10.1371/journal.pone.0265875. eCollection 2022.

ABSTRACT

Rainfall fluctuation is directly affected by the Earth’s climate change. It can be described using the coefficient of variation (CV). Similarly, the ratio of CVs can be used to compare the rainfall variation between two regions. The ratio of CVs has been widely used in statistical inference in a number of applications. Meanwhile, the confidence interval constructed with this statistic is also of interest. In this paper, confidence intervals for the ratio of two independent CVs of lognormal distributions with excess zeros using the fiducial generalized confidence interval (FGCI), Bayesian methods based on the left-invariant Jeffreys, Jeffreys rule, and uniform priors, and the Wald and Fieller log-likelihood methods are proposed. The results of a simulation study reveal that the highest posterior density (HPD) Bayesian using the Jeffreys rule prior method performed the best in terms of the coverage probability and the average length for almost all cases of small sample size and a large sample size together with a large variance and a small proportion of non-zero values. The performance of the statistic is demonstrated on two rainfall datasets from the central and southern regions in Thailand.

PMID:35320313 | DOI:10.1371/journal.pone.0265875

PLoS One. 2022 Mar 23;17(3):e0265342. doi: 10.1371/journal.pone.0265342. eCollection 2022.

ABSTRACT

INTRODUCTION: Sickle cell disease (SCD) is an inherited hemoglobinopathy that predominantly affects African Americans in the United States. The disease is associated with complications leading to high healthcare utilization rates, including emergency department (ED) visits and hospitalizations. Optimal SCD care requires a multidisciplinary approach involving SCD specialists to ensure preventive care, minimize complications and prevent unnecessary ED visits and hospitalizations. However, most individuals with SCD receive sub-optimal care or are unaffiliated with care (have not seen an SCD specialist). We aimed to identify barriers to care from the perspective of individuals with SCD in a multi-state sample.

METHODS: We performed a multiple methods study consisting of surveys and interviews in three comprehensive SCD centers from March to June 2018. Interviews were transcribed and coded, exploring themes around barriers to care. Survey questions on the specific themes identified in the interviews were analyzed using summary statistics.

RESULTS: We administered surveys to 208 individuals and conducted 44 in-depth interviews. Barriers to care were identified and classified according to ecological level (i.e., individual, family/interpersonal, provider, and socio-environmental/organizational level). Individual-level barriers included lack of knowledge in self-management and disease severity. Family/interpersonal level barriers were inadequate caregiver support and competing life demands. Provider level barriers were limited provider knowledge, provider inexperience, poor provider-patient relationship, being treated differently, and the provider’s lack of appreciation of the patient’s SCD knowledge. Socio-environmental/organizational level barriers included limited transportation, lack of insurance, administrative barriers, poor care coordination, and reduced access to care due to limited clinic availability, services provided or clinic refusal to provide SCD care.

CONCLUSION: Participants reported several multilevel barriers to SCD care. Strategies tailored towards reducing these barriers are warranted. Our findings may also inform interventions aiming to locate and link unaffiliated individuals to care.

PMID:35320302 | DOI:10.1371/journal.pone.0265342

PLoS One. 2022 Mar 23;17(3):e0265624. doi: 10.1371/journal.pone.0265624. eCollection 2022.

ABSTRACT

BACKGROUND: Data on health status outcomes after spontaneous coronary artery dissection (SCAD) are limited.

METHODS AND FINDINGS: Using the Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients (VIRGO) study we compared patients with SCAD and other acute myocardial infarction (AMI) at presentation (baseline), 1-month, and-12 months using standardized health status instruments. Among 3572 AMI patients ≤ 55 years, 67 had SCAD. SCAD patients were younger (median age (IQR) 45 (40.5-51) years vs. 48 (44-52) in other AMI, p = 0.003), more often female (92.5% vs. 66.6%), have college education (73.1% vs. 51.7%) and household income >$100,000 (43.3% vs. 17.7% (All p<0.001). SCAD patients at baseline had higher mean ± SD Short Form-12 [SF-12] physical component scores [PCS] (48.7±10.2 vs. 43.8±12.1, p<0.001) and mental component scores [MCS] (49.6±12.4 vs. 45.4±12.5, p = 0.008), and at 12-months [PCS (50.1±9.0 vs. 44.3±12.3, p<0.001) and MCS (53±10.1 vs 50.2±11.0, p = 0.045)]. The Euro-Quality of Life Scale [EQ-5D] VAS and EQ-5D index scores were similar at baseline, but higher at 12-months for SCAD (EQ-5D VAS: 82.2±10.2 vs. 72.3±21.0, p<0.001; EQ-5D index scores; 90.2±15.3 vs. 83.7±19.8, p = 0.012). SCAD patients had better baseline Seattle Angina Questionnaire [SAQ] physical limitation (88.8±20.1 vs. 81.2±25.4, p = 0.017). At 12-months SCAD patients had better physical limitation (98.0±8.5 vs. 91.4±18.8, p = 0.007), angina frequency (96.4±8.8 vs. 91.3±16.8, p = 0.018) and quality of life scores (80.7±14.7 vs 72.2±23.2, p = 0.005). Magnitude of change in health status from baseline to 12-months was not statistically different between the groups. After adjustment for time and comorbidities there remained no difference in most health status outcomes.

CONCLUSIONS: SCAD patients fare marginally better than other AMI patients on most health status instruments and have similar 12-month health status recovery. Better pre-event health status suggests a need to modify exercise prescriptions and cardiac rehabilitation protocols to better assist this physically active population to recover.

PMID:35320296 | DOI:10.1371/journal.pone.0265624

J Magn Reson Imaging. 2022 Mar 23. doi: 10.1002/jmri.28168. Online ahead of print.

ABSTRACT

BACKGROUND: The relationship of tissue chemistry to breast density and cancer risk has not been documented despite breast density being a known risk factor.

PURPOSE: To investigate whether distinct chemical profiles associated with breast density and cancer risk are identified in healthy breast tissue using in vivo two-dimensional correlated spectroscopy (2D COSY).

STUDY TYPE: Prospective.

POPULATION: One-hundred-seven participants including 55 at low risk and 52 at high risk of developing breast cancer.

FIELD STRENGTH/SEQUENCE: 3 T/ axial/ T1, T2, 2D COSY.

ASSESSMENT: Two radiologists defined breast density on T2. Interobserver variability assessed. Peak volumes normalized to methylene at (1.30, 1.30) ppm as internal shift reference.

STATISTICAL TESTS: Chi-squared/Mann-Whitney/Kappa statistics/Kruskal Wallis/pairwise analyses. Significance level 0.05.

RESULTS: Ten percentage were fatty breasts, 39% scattered fibroglandular, 35% heterogeneously dense, and 16% extremely dense. Interobserver variability was excellent (kappa = 0.817). Sixty percentage (64/107) were premenopausal. Four distinct tissue chemistry categories were identified: low-density (LD)/premenopausal, high-density (HD)/premenopausal, LD/postmenopausal, and HD/postmenopausal. Compared to LD, HD breast chemistry showed significant increases of cholesterol (235%) and lipid unsaturation (33%). In the low-risk category, postmenopausal women with dense breasts recorded the largest significant changes including cholesterol methyl 540%, lipid unsaturation 207%, glutamine/glutamate 900%, and choline/phosphocholine 800%. In the high-risk cohort, premenopausal women with HD recorded a more active chemical profile with significant increases in choline/phosphocholine 1100%, taurine/glucose 550% and cholesterol sterol 250%.

DATA CONCLUSION: Four distinct chemical profiles were identified in healthy breast tissue based on breast density and menopausal status in participants at low and high risk. Gradual increase in neutral lipid content and metabolites was noted in both risk groups across categories in different order. In low risk, the HD postmenopausal category exhibited the highest metabolic activity, while women at high risk exhibited the highest lipid content and metabolic activity in the HD premenopausal category.

LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 3.

PMID:35319148 | DOI:10.1002/jmri.28168

Head Neck. 2022 Mar 23. doi: 10.1002/hed.27038. Online ahead of print.

ABSTRACT

BACKGROUND: To assess the efficacy and safety of preoperative embolization (PE) in patients with carotid body tumor (CBTs).

METHODS: In a single-center retrospective cohort study, 127 patients underwent surgical resection of CBTs from January 2003 to December 2019. One-to-one propensity score matching was conducted between patients with or without PE.

RESULTS: Thirty-two (25.2%) patients received PE. After propensity score matching, no statistically significant differences were found in the baseline characteristics of 28 patients in each group. Compared with NPE group, operative time and estimated blood loss (EBL) were significantly reduced in the PE group. The incidence of stroke, perioperative complications, intraoperative blood transfusion, vascular reconstruction, hospital stay, tumor recurrence, and all-cause mortality were not different between the PE and NPE group.

CONCLUSIONS: Preoperative embolization was efficient and safe with a reduction of intraoperative blood loss and operative time during CBT resection.

PMID:35319144 | DOI:10.1002/hed.27038

J Magn Reson Imaging. 2022 Mar 23. doi: 10.1002/jmri.28172. Online ahead of print.

ABSTRACT

BACKGROUND: Advanced diffusion-based MRI biomarkers may provide insight into microstructural and perfusion changes associated with neurodegeneration and cognitive decline.

PURPOSE: To assess longitudinal microstructural and perfusion changes using apparent diffusion coefficient (ADC) and intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) parameters in cognitively impaired (CI) and healthy control (HC) groups.

STUDY TYPE: Prospective/longitudinal.

POPULATION: Twelve CI patients (75% female) and 13 HC subjects (69% female).

FIELD STRENGTH/SEQUENCE: 3 T; Spin-Echo-IVIM-DWI.

ASSESSMENT: Two MRI scans were performed with a 12-month interval. ADC and IVIM-DWI metrics (diffusion coefficient [D] and perfusion fraction [f]) were generated from monoexponential and biexponential fits, respectively. Additionally, voxel-based correlations were evaluated between change in Montreal Cognitive Assessment (ΔMoCA) and baseline imaging parameters.

STATISTICAL TESTS: Analysis of covariance with sex and age as covariates was performed for main effects of group and time (false discovery rate [FDR] corrected) with post hoc comparisons using Bonferroni correction. Partial-η² and Hedges’ g were used for effect-size analysis. Spearman’s correlations (FDR corrected) were used for the relationship between ΔMoCA score and imaging. P < 0.05 was considered statistically significant.

RESULTS: Significant differences were found for the main effects of group (HC vs. CI) and time. For group effects, higher ADC, IVIM-D, and IVIM-f were observed in the CI group compared to HC (ADC: 1.23 ± 0.08^. 10^-3 vs. 1.09 ± 0.07^. 10^-3 mm² /sec; IVIM-D: 0.82 ± 0.01^. 10^-3 vs. 0.73 ± 0.01^. 10^-3 mm² /sec; and IVIM-f: 0.317 ± 0.008 vs. 0.253 ± 0.009). Significantly higher ADC, IVIM-D, and IVIM-f values were observed in the CI group after 12 months (ADC: 1.45 ± 0.05^. 10^-3 vs. 1.50 ± 0.07^. 10^-3 mm² /sec; IVIM-D: 0.87 ± 0.01^. 10^-3 vs. 0.94 ± 0.02^. 10^-3 mm² /sec; and IVIM-f: 0.303 ± 0.007 vs. 0.332 ± 0.008), but not in the HC group at large effect size. ADC, IVIM-D, and IVIM-f negatively correlated with ΔMoCA score (ρ = -0.49, -0.51, and -0.50, respectively).

DATA CONCLUSION: These findings demonstrate that longitudinal differences between CI and HC cohorts can be measured using IVIM-based metrics.

LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2.

PMID:35319142 | DOI:10.1002/jmri.28172