Tag: pubmed

Ultrasonics. 2023 Jul 5;134:107103. doi: 10.1016/j.ultras.2023.107103. Online ahead of print.

ABSTRACT

This study aims to investigate the feasibility of combined segmentation for the separation of lesions from non-ablated regions, which allows surgeons to easily distinguish, measure, and evaluate the lesion area, thereby improving the quality of high-intensity focused-ultrasound (HIFU) surgery used for the non-invasive tumor treatment. Given that the flexible shape of the Gamma mixture model (GΓMM) fits the complex statistical distribution of samples, a method combining the GΓMM and Bayes framework is constructed for the classification of samples to obtain the segmentation result. An appropriate normalization range and parameters can be used to rapidly obtain a good performance of GΓMM segmentation. The performance values of the proposed method under four metrics (Dice score: 85%, Jaccard coefficient: 75%, recall: 86%, and accuracy: 96%) are better than those of conventional approaches including Otsu and Region growing. Furthermore, the statistical result of sample intensity indicates that the finding of the GΓMM is similar to that obtained by the manual method. These results indicate the stability and reliability of the GΓMM combined with the Bayes framework for the segmentation of HIFU lesions in ultrasound images. The experimental results show the possibility of combining the GΓMM with the Bayes framework to segment lesion areas and evaluate the effect of therapeutic ultrasound.

PMID:37437399 | DOI:10.1016/j.ultras.2023.107103

Epilepsy Behav. 2023 Jul 10;145:109351. doi: 10.1016/j.yebeh.2023.109351. Online ahead of print.

ABSTRACT

BACKGROUND: The Accreditation Council for Graduate Medical Education (ACGME) milestones state that neurology residents should be able to “interpret common EEG abnormalities, recognize normal EEG variants, and create a report.” Yet, recent studies have shown that only 43% of neurology residents express confidence in interpreting EEG without supervision and can recognize less than half of normal and abnormal EEG patterns. Our objective was to create a curriculum to improve both confidence and competence in reading EEGs.

METHODS: At Vanderbilt University Medical Center (VUMC), adult and pediatric neurology residents have required EEG rotations in their first and second years of neurology residency and can choose an EEG elective in their third year. A curriculum consisting of specific learning objectives, self-directed modules, EEG lectures, epilepsy-related conferences, supplemental educational material, and tests was created for each of the three years of training.

RESULTS: Since the implementation of an EEG curriculum at VUMC from September 2019 until November 2022, 12 adult and 21 pediatric neurology residents completed pre- and post-rotation tests. Among the 33 residents, there was a statistically significant improvement in post-rotation test scores, with a mean score improvement of 17% (60.0 ± 12.9 to 77.9 ± 11.8, n = 33, p < 0.0001). When differentiated by training, the mean improvement of 18.8% in the adult cohort was slightly higher than in the pediatric cohort, 17.3%, though it was not significantly different. Overall improvement was significantly increased in the junior resident cohort with a 22.6% improvement in contrast to 11.5% in the senior resident cohort (p = 0.0097 by Student’s t-test, n = 14 junior residents and 15 senior residents).

DISCUSSION: With the creation of an EEG curriculum specific to each year of neurology residency, adult and pediatric neurology residents demonstrated a statistically significant mean improvement between pre- and post-rotation test scores. The improvement was significantly higher in junior residents in contrast to senior residents. Our structured and comprehensive EEG curriculum objectively improved EEG knowledge in all neurology residents at our institution. The findings may suggest a model which other neurology training programs may consider for the implementation of a similar curriculum to both standardize and address gaps in resident EEG education.

PMID:37437392 | DOI:10.1016/j.yebeh.2023.109351

J Trace Elem Med Biol. 2023 Jun 30;79:127257. doi: 10.1016/j.jtemb.2023.127257. Online ahead of print.

ABSTRACT

INTRODUCTION AND AIM: Lead is a ubiquitous element found in the earth crust. There is no known physiologic role of lead in human body and hence any amount of lead present in human tissue considered as a contamination. Several studies on lead toxicity show that, occupational exposure remains the main source for lead toxicity and is emerging as important public health problem. Burden and severity of occupational exposure of lead and its clinical significance are gaining more interest in the field of toxicology. Only limited studies are available and there is scarcity of epidemiology data to assess the blood lead levels of workers and the contribution of common workplace practices to lead exposure in India especially from our region. So, the current study is designed to assess the blood lead levels (BLL) and its clinical significance among high risk workers especially painters working in the construction and public private sector in Chennai based population.

MATERIALS AND METHODS: This cross-sectional case control study included 122 painters and 122 healthy individuals. A detailed questionnaire about demographic details, personal habits, work related safety precautions, presenting symptoms of lead toxicity were given to painter followed by detailed medical examination and blood investigations including blood lead levels were collected and statistically analyzed. The t-test were used to compare mean blood lead levels and to investigate the associations between specific job type, use of self-protection device,sex, service years and occurrence of non-specific symptoms with BLLs.

RESULTS: The mean BLL of the painters were less than the recommended threshold level. Among painters 13.1% were categorized under BLL > 10 μg/dL. The higher BLL among the painters were directly proportional to year of experience and poor usage of personal protective materials. The levels of Hb, HCT and eosinophil were much correlated with lead toxicity. A marginal significance were observed in some parameters especially urea and creatinine when compared with control. The Cognitive dysfunction, hypertension and renal dysfunction were also observed among the painters.

CONCLUSION: The BLL in painters among our group were minimal compared to biological reference value. Duration of exposure and association of patient’s clinical features like cognitive dysfunction, hypertension and renal dysfunction conditions were observed and this should be carefully monitored and study on huge population of painters with longitudinal aspect is recommended to rule out the clinical correlation of lead toxicity.

PMID:37437390 | DOI:10.1016/j.jtemb.2023.127257

Environ Int. 2023 Jun 8;178:108005. doi: 10.1016/j.envint.2023.108005. Online ahead of print.

ABSTRACT

Many United States (US) cities are experiencing urban heat islands (UHIs) and climate change-driven temperature increases. Extreme heat increases cardiovascular disease (CVD) risk, yet little is known about how this association varies with UHI intensity (UHII) within and between cities. We aimed to identify the urban populations most at-risk of and burdened by heat-related CVD morbidity in UHI-affected areas compared to unaffected areas. ZIP code-level daily counts of CVD hospitalizations among Medicare enrollees, aged 65-114, were obtained for 120 US metropolitan statistical areas (MSAs) between 2000 and 2017. Mean ambient temperature exposure was estimated by interpolating daily weather station observations. ZIP codes were classified as low and high UHII using the first and fourth quartiles of an existing surface UHII metric, weighted to each have 25% of all CVD hospitalizations. MSA-specific associations between ambient temperature and CVD hospitalization were estimated using quasi-Poisson regression with distributed lag non-linear models and pooled via multivariate meta-analyses. Across the US, extreme heat (MSA-specific 99th percentile, on average 28.6 °C) increased the risk of CVD hospitalization by 1.5% (95% CI: 0.4%, 2.6%), with considerable variation among MSAs. Extreme heat-related CVD hospitalization risk in high UHII areas (2.4% [95% CI: 0.4%, 4.3%]) exceeded that in low UHII areas (1.0% [95% CI: -0.8%, 2.8%]), with upwards of a 10% difference in some MSAs. During the 18-year study period, there were an estimated 37,028 (95% CI: 35,741, 37,988) heat-attributable CVD admissions. High UHII areas accounted for 35% of the total heat-related CVD burden, while low UHII areas accounted for 4%. High UHII disproportionately impacted already heat-vulnerable populations; females, individuals aged 75-114, and those with chronic conditions living in high UHII areas experienced the largest heat-related CVD impacts. Overall, extreme heat increased cardiovascular morbidity risk and burden in older urban populations, with UHIs exacerbating these impacts among those with existing vulnerabilities.

PMID:37437316 | DOI:10.1016/j.envint.2023.108005

J Chem Theory Comput. 2023 Jul 12. doi: 10.1021/acs.jctc.3c00387. Online ahead of print.

ABSTRACT

We report a Monte Carlo simulation study of length-scale-dependent density fluctuations in cavities in the coarse-grained mW representation of water at ambient conditions. Specifically, we use a combination of test particle insertion and umbrella sampling techniques to examine the full range of water occupation states in spherical cavities up to 6.3 Å radius in water. As has previously been observed, water density fluctuations are found to be effectively Gaussian in nature for atomic-scale cavities, but as the cavities get larger, they exhibit a non-Gaussian “fat-tail” distribution for lower occupancy states. We introduce a new statistical thermodynamic approach to analyze non-Gaussian fluctuations based on the radial distribution of waters about cavities with varying numbers of waters within its boundaries. It is shown that the onset of these non-Gaussian fluctuations is a result of the formation of a bubble within the cavity as it is emptied, which is accompanied by the adsorption of waters onto its interior surface. We revisit a theoretical framework we previously introduced to describe Gaussian fluctuations within cavities to incorporate bubble formation by including surface tension contributions. This modified theory accurately describes density fluctuations within both atomic and meso-scale cavities. Moreover, the theory predicts the transition from Gaussian to non-Gaussian fluctuations at a specific cavity occupancy, in excellent agreement with simulation observations.

PMID:37437298 | DOI:10.1021/acs.jctc.3c00387

J Clin Endocrinol Metab. 2023 Jul 13:dgad414. doi: 10.1210/clinem/dgad414. Online ahead of print.

ABSTRACT

CONTEXT: The inclusion of transgender people in elite sport has been a topic of debate. This narrative review examines the impact of gender affirming hormone therapy (GAHT) on physical performance, muscle strength and markers of endurance.

EVIDENCE ACQUISITION: MEDLINE and Embase were searched using terms to define the population (transgender), intervention (GAHT) and physical performance outcomes.

EVIDENCE SYNTHESIS: Existing literature is comprised of cross-sectional or small uncontrolled longitudinal studies of short duration. In non-athletic trans men starting testosterone therapy, within 1 year, muscle mass and strength increased, and by 3 years, physical performance (push-ups, sit-ups, run time) improved to the level of cisgender men.In non-athletic trans women, feminising hormone therapy increased fat mass by approximately 30% and decreased muscle mass by approximately 5% after 12 months and steadily declined beyond 3 years. Whilst absolute lean mass remains higher in trans women, relative percentage lean mass and fat mass (and muscle strength corrected for lean mass), hemoglobin and VO2 peak corrected for weight was no different to cisgender women. After 2 years of GAHT, no advantage was observed for physical performance measured by running time or in trans women. By 4 years, there was no advantage in sit-ups. Whilst push-ups performance declined in trans women, a statistical advantage remained relative to cisgender women.

CONCLUSIONS: Limited evidence suggests that physical performance of non-athletic trans people who have undergone GAHT for at least 2 years approaches that of cisgender controls. Further controlled longitudinal research is needed in trans athletes and non-athletes.

PMID:37437247 | DOI:10.1210/clinem/dgad414

Cutan Ocul Toxicol. 2023 Jul 12:1-8. doi: 10.1080/15569527.2023.2235429. Online ahead of print.

ABSTRACT

PURPOSE: To evaluate choroidal thickness and choroidal vascular index (CVI) in healthy women using the combined oral contraceptive pill (COCp).

METHODS: This prospective study included 30 women using COCp (3 mg drospirenone/0.03 mg ethinylestradiol) for contraception for at least 1 year and 30 healthy women who did not use COCp. Intraocular pressure (IOP), axial length (AL) and body mass index (BMI) values ​​of all participants were recorded. Subfoveal choroidal thickness (SCT) and choroidal thickness at 1500 micron distance in nasal and temporal regions (NCT, TCT) were measured through optical coherence tomography (OCT) images. Luminal, stromal and total choroidal area values were evaluated by binarization method. The ratio of the luminal choroidal area to the total choroidal area was determined as the CVI value.

RESULTS: There was no statistically significant difference in IOP and AL values between the two groups at no significant difference age and BMI index (p > 0.05, for all). SCT, NCT and TCT values were no significant difference in the two groups (p> 0.05, for all). Luminal and stromal choroidal area values ​​were found to be lower in the group using COCp (p = 0.01, p = 0.02 respectively). The CVI value was 62.1 ± 3.6% in the COCp group and 65.6 ± 4.3% in the control group. There was a significant difference between the two groups in terms of CVI value (p = 0.002).

CONCLUSION: To our knowledge, this is the first study to evaluate CVI in women using COCp, and CVI was found to be lower in individuals using COCp. Therefore, CVI can be used in the follow-up of possible ocular pathologies that may develop in individuals using COCp.

PMID:37437218 | DOI:10.1080/15569527.2023.2235429

J Am Coll Health. 2023 Jul 12:1-25. doi: 10.1080/07448481.2023.2227725. Online ahead of print.

ABSTRACT

Objective: Examine the impact of the campus food environment on postsecondary students’ dietary behaviors (e.g., dietary intake) and food purchasing. Participants: Students currently attending a postsecondary institution, all ages and geographic locations included. Methods: A systematic search from January 2000-October 2022 was conducted in six databases using postsecondary education, food environment, and diet related keywords. Results: In total, 25 quantitative and 10 qualitative studies were extracted. All quantitative studies that conducted statistical analyses (n = 15) reported a statistically significant relationship between the campus food environment and dietary intake, including both positive and negative effects. All qualitative studies (n = 10) discussed students’ experience of the campus food environment influencing their diet. Conclusions: This review found moderate evidence that the campus food environment has an impact on postsecondary students’ dietary behaviors. A campus environment that has healthy foods accessible, affordable, and acceptable for postsecondary students may have a beneficial impact on students’ dietary intake.

PMID:37437204 | DOI:10.1080/07448481.2023.2227725

Neural Comput. 2023 Jul 12:1-48. doi: 10.1162/neco_a_01601. Online ahead of print.

ABSTRACT

Understanding the effect of spike-timing-dependent plasticity (STDP) is key to elucidating how neural networks change over long timescales and to design interventions aimed at modulating such networks in neurological disorders. However, progress is restricted by the significant computational cost associated with simulating neural network models with STDP and by the lack of low-dimensional description that could provide analytical insights. Phase-difference-dependent plasticity (PDDP) rules approximate STDP in phase oscillator networks, which prescribe synaptic changes based on phase differences of neuron pairs rather than differences in spike timing. Here we construct mean-field approximations for phase oscillator networks with STDP to describe part of the phase space for this very high-dimensional system. We first show that single-harmonic PDDP rules can approximate a simple form of symmetric STDP, while multiharmonic rules are required to accurately approximate causal STDP. We then derive exact expressions for the evolution of the average PDDP coupling weight in terms of network synchrony. For adaptive networks of Kuramoto oscillators that form clusters, we formulate a family of low-dimensional descriptions based on the mean-field dynamics of each cluster and average coupling weights between and within clusters. Finally, we show that such a two-cluster mean-field model can be fitted to synthetic data to provide a low-dimensional approximation of a full adaptive network with symmetric STDP. Our framework represents a step toward a low-dimensional description of adaptive networks with STDP and could, for example inform the development of new therapies aimed at maximizing the long-lasting effects of brain stimulation.

PMID:37437202 | DOI:10.1162/neco_a_01601

J Am Coll Health. 2023 Jul 12:1-6. doi: 10.1080/07448481.2023.2230303. Online ahead of print.

ABSTRACT

Objective: To examine the interaction between high school (HS) sports participation and injury history with current moderate-to-vigorous physical activity (MVPA) among young adults. Participants: Participants (N = 236) were 18-25 years old, not currently injured, and reported no physical activity limitations. Methods: Participants completed online demographic, injury history, and physical activity surveys. A two-way analysis of covariance was used to test the interaction between HS athlete status and previous injury severity on current self-reported MVPA. Results: Participants were 22.2 ± 2.1 years, primarily White (81.8%) or Asian (6.4%), and female (77.5%). After including body mass index and race as covariates, there was a statistically significant interaction between HS athlete status and previous injury history such that current MVPA was higher among former HS athletes compared to HS recreational/nonathletes when individuals reported no injuries or mild injury severity. MVPA was similar across athlete status groups when participants reported high levels of injury severity. Conclusions: Future studies should examine whether young adults who have experienced multiple and/or severe injuries as competitive HS athletes have unique physical activity barriers.

PMID:37437201 | DOI:10.1080/07448481.2023.2230303