Tag: nevin manimala

Biomech Model Mechanobiol. 2021 Jul 31. doi: 10.1007/s10237-021-01499-5. Online ahead of print.

ABSTRACT

We consider a one-dimensional morphoelastic model describing post-burn scar contraction. Contraction can lead to a limited range of motion (contracture). Reported prevalence of burn scar contractures are 58.6% at 3-6 weeks and 20.9% at 12 months post-reconstructive surgery after burns. This model describes the displacement of the dermal layer of the skin and the development of the effective Eulerian strain in the tissue. Besides these components, the model also contains components that play a major role in the skin repair after trauma. These components are signaling molecules, fibroblasts, myofibroblasts, and collagen. We perform a sensitivity analysis for many parameters of the model and use the results for a feasibility study. In this study, we test whether the model is suitable for predicting the extent of contraction in different age groups. To this end, we conduct an extensive literature review to find parameter values. From the sensitivity analysis, we conclude that the most sensitive parameters are the equilibrium collagen concentration in the dermal layer, the apoptosis rate of fibroblasts and myofibroblasts, and the secretion rate of signaling molecules. Further, although we can use the model to simulate significant distinct contraction densities in different age groups, our results differ from what is seen in the clinic. This particularly concerns children and elderly patients. In children we see more intense contractures if the burn injury occurs near a joint, because the growth induces extra forces on the tissue. Elderly patients seem to suffer less from contractures, possibly because of excess skin.

PMID:34331622 | DOI:10.1007/s10237-021-01499-5

Environ Technol. 2021 Jul 30:1-33. doi: 10.1080/09593330.2021.1963323. Online ahead of print.

ABSTRACT

Recent studies point out losses of 30-40% of the produced methane in the effluent of anaerobic reactors treating sewage, reducing the renewable energy potential and the environmental footprint. A novel bench-scale upflow anaerobic hybrid (UAHB) reactor combining a sludge blanket at the bottom and a filter media at the top, both with three-phase separators, was proposed to evaluate the recovery of dissolved methane. UAHB was operated with volumetric organic loading rate of 1.24 kgCOD m^-3 d^-1 and hydraulic retention time of 8 h for 218 days to evaluate the influence of temperature (18, 23, and 28 °C) in the methane dissolved in the effluent and collected from three-phase separators. Chemical oxygen demand (COD) and total suspended solids (TSS) removals efficiencies remained constant during the operation and equal to 90 and 95%, respectively, related to the activity of biomass retained in the filter media. Temperature increase influenced more the methane production in the sludge blanket rather than in the upper bed. The volume of recovered methane increased about 20% with the installation of the support media and the upper three-phase separator (3PHS). The loss of methane dissolved in the effluent was strongly influenced by the temperature, and higher with the decrease of this parameter. The statistical test indicated that there is no correlation between total methane production and temperature (p-value = 0.8803) for the upper 3PHS. Thus, it can be concluded that the evaluated temperatures did not influence the global efficiency and the total methane yield of the UAHB reactor.

PMID:34330187 | DOI:10.1080/09593330.2021.1963323

J Gerontol Soc Work. 2021 Jul 30:1-11. doi: 10.1080/01634372.2021.1953662. Online ahead of print.

ABSTRACT

The purpose of this study was to examine the temporal trends and dynamics of financial hardship among older adults in the U.S. between 2006 and 2016 using the Health and Retirement Study. Sample included a total of 13,537 eligible person observations with a median age of 68 years. Financial hardship included measures of difficulty paying bills, food insecurity, taking less medication due to cost, and ongoing financial strain. Regression analyses were performed using a three-wave quadrennial model to estimate the prevalence of financial hardship over time, to explore temporal patterns and identify persistent hardship. Findings reveal that 51% of respondents who experienced food insecurity at one or more waves were transient. This pattern was similar to respondents who experienced ongoing financial strain (52% transient). Respondents who reported difficulty paying bills (68%) and reduced medications due to cost (62%) were also transient. Significant predictors across all four domains of financial hardship include age, years of education, marital status, self-rated health. Being African American was positively associated with reduced medication use and food insecurity. This study provides insight into the temporal dynamics of financial hardship in later life. It also highlights the contiguous, intermediate and transient nature of financial hardship among older adult populations.

PMID:34330197 | DOI:10.1080/01634372.2021.1953662

Semin Ophthalmol. 2021 Jul 30:1-5. doi: 10.1080/08820538.2021.1955939. Online ahead of print.

ABSTRACT

PURPOSE: Binocular balancing is an important component of refractive correction to avoid asthenopic complaints. Polaroid filters are commonly used for binocular balancing; they rely on subjective examination and cannot represent daily visual activities. We describe a new examination approach to evaluate binocular balance with retinoscopy, which is an objective examination method and does not require strict patient cooperation.

METHODS: Healthy young individuals with refractive errors (under the age of 40) were included in this study. Each patient was examined by three different ophthalmologists in the same room at 20-min intervals. The first ophthalmologist performed refractive examination separately for each eye, the second physician used binocular balance tests with polaroid glasses, and the third physician practiced binocular balance test with retinoscopy. After completion of clinical examinations, autorefractometry was repeated with cycloplegia. The difference between the spherical equivalents (SE) of the eyes was calculated for each method and compared with the SE difference obtained by cycloplegic autorefractometry. The SPSS 21.0 software was used for the statistical tests.

RESULTS: The study included 30 patients (16 males, 14 females) and the mean age of the patients was 21 ± 8.5 years (range 10-37 years). There was no significant difference between the four groups for the interocular difference of SE (Greenhouse-Geisser F = 1.390, p = 0.257). The highest correlation was found between the retinoscopic binocular balance technique and cycloplegic autorefractometry (r = 0.878, p < 0.001). In addition, the intraclass correlation coefficient and the 95% limits of agreement supported strong agreement.

CONCLUSION: Currently used binocular examination tests are subjective and some patients give inconsistent answers impairing the reliability of the outcome. These tests cannot be performed on patients with limited ability to cooperate. This study demonstrates that the use of retinoscopy in the evaluation of binocular balance delivers reliable results and is a low-cost, practical approach to address the above-mentioned problems.

PMID:34330203 | DOI:10.1080/08820538.2021.1955939

Anesthesiology. 2021 Jul 30. doi: 10.1097/ALN.0000000000003871. Online ahead of print.

ABSTRACT

Clinical prediction models in anesthesia and surgery research have many clinical applications including preoperative risk stratification with implications for clinical utility in decision-making, resource utilization, and costs. It is imperative that predictive algorithms and multivariable models are validated in a suitable and comprehensive way in order to establish the robustness of the model in terms of accuracy, predictive ability, reliability, and generalizability. The purpose of this article is to educate anesthesia researchers at an introductory level on important statistical concepts involved with development and validation of multivariable prediction models for a binary outcome. Methods covered include assessments of discrimination and calibration through internal and external validation. An anesthesia research publication is examined to illustrate the process and presentation of multivariable prediction model development and validation for a binary outcome. Properly assessing the statistical and clinical validity of a multivariable prediction model is essential for reassuring the generalizability and reproducibility of the published tool.

PMID:34330146 | DOI:10.1097/ALN.0000000000003871

Asia Pac J Public Health. 2021 Jul 30:10105395211036275. doi: 10.1177/10105395211036275. Online ahead of print.

ABSTRACT

Tobacco smoking is a leading cause of premature death. Smoking prevalence in Vietnam ranks among the highest in Southeast Asia. Given the important role of health care workers (HCWs) in promoting and supporting smoking cessation, this project aimed to characterize the prevalence of smoking among HCWs in Vietnam, and their attitudes toward smoking cessation interventions. A cross-sectional survey was conducted among care workers in 4 levels of the health system, within 4 provinces of Vietnam. Descriptive statistics evaluated participant attitudes, perception, behaviors, and knowledge about smoking. Multivariable logistic regression models evaluated risk factors for smoking. Among 3343 HCWs, 7.5% identified as current smokers, comprising 22.2% males and 0.5% of females. Males had substantially greater odds (adjusted odds ratio = 55.3; 95% confidence interval = 29.0-105.6) of identifying as current smokers compared with females. HCWs in urban settings had higher odds of identifying as smokers compared with rural workers (adjusted odds ratio = 1.72; 95% confidence interval = 1.23-2.24). Strong support for smoking cessation policies and interventions were identified, even among staff who smoked. HCWs play an integral role in identifying smokers and supporting smoking cessation interventions for their patients. Efforts to support affordable smoking cessation interventions within health facilities are likely to contribute to a reduction in smoking prevalence in Vietnam.

PMID:34330179 | DOI:10.1177/10105395211036275

J Perinat Neonatal Nurs. 2021 Jul-Sep 01;35(3):247-257. doi: 10.1097/JPN.0000000000000556.

ABSTRACT

Benefits of skin-to-skin contact (SSC) are documented but often delayed in the extremely preterm population due to medical complexity and staff misconceptions about safety. This quality improvement initiative was designed to increase SSC utilization among infants born before 29 weeks’ gestation regardless of respiratory support by addressing nursing barriers inhibiting SSC. A pre-/postsurvey evaluated comfort level performing and perceived barriers to SSC utilization. Implementation consisted of an updated unit-specific SSC protocol and tailored education specific to identified barriers. Evaluation included SSC rates and maternal human milk usage in the first 30 days of life. In total, 81 patients (22-28 weeks, 370-1410 g) were included. SSC rates ranged from 3.3% to 17.7% at baseline and increased to 33.2% to 39.1% postintervention. Maternal human milk utilization increased above target (≥75%) postintervention for days 7 and 14, but declined towards baseline on days 21 and 30. A statistically significant increase was observed in nursing comfort level when performing SSC for intubated infants as well as infants with a peripherally inserted central catheter or umbilical venous catheter. SSC rates increased with infants younger than 29 weeks requiring intubation and central line management, possibly as a result of greater nursing comfort surrounding with SSC.

PMID:34330136 | DOI:10.1097/JPN.0000000000000556

J Perinat Neonatal Nurs. 2021 Jul-Sep 01;35(3):266-274. doi: 10.1097/JPN.0000000000000557.

ABSTRACT

It is very important that infants are exclusively breastfed for the first 6 months of life and then that breastfeeding is continued until 2 years of age. In this study, we aimed to determine the rate of exclusive breastfeeding for the first 6 months of life following birth and the factors associated with continuation of exclusive breastfeeding. The study was a retrospective cohort study. The study population consists of infants born in Akdeniz University Hospital. Infants born between June 1, 2016, and June 1, 2017 (n = 1402) were included in the sample. For analysis of data, descriptive statistics, χ2 test, t test, and logistic regression test were employed. The rate of exclusive breastfeeding for the first 6 months was 29.8%. Further analysis revealed that chances of breastfeeding exclusivity for the first 6 months were increased by 1.6-fold if the father had higher education, by 1.4-fold if the infant was not given formula in the hospital, by approximately 4-fold if feeding bottle was not used, and by 1.7-fold in the absence of problems related to breastfeeding. The study results showed that success in exclusive breastfeeding was influenced by several factors. We recommended that modifiable factors associated with the success of exclusive breastfeeding be well managed.

PMID:34330139 | DOI:10.1097/JPN.0000000000000557

Neuroimage Clin. 2021 Jul 24;31:102767. doi: 10.1016/j.nicl.2021.102767. Online ahead of print.

ABSTRACT

Maintaining high levels of daily activity and physical capability have been proposed as important constituents to promote healthy brain and cognitive aging. Studies investigating the associations between brain health and physical activity in late life have, however, mainly been based on self-reported data or measures designed for clinical populations. In the current study, we examined cross-sectional associations between physical activity, recorded by an ankle-positioned accelerometer for seven days, physical capability (grip strength, postural control, and walking speed), and neuroimaging based surrogate markers of brain health in 122 healthy older adults aged 65-88 years. We used a multimodal brain imaging approach offering complementary structural MRI based indicators of brain health: global white matter fractional anisotropy (FA) and mean diffusivity (MD) based on diffusion tensor imaging, and subcortical and global brain age based on brain morphology inferred from T1-weighted MRI data. In addition, based on the results from the main analysis, follow-up regression analysis was performed to test for association between the volume of key subcortical regions of interest (hippocampus, caudate, thalamus and cerebellum) and daily steps, and a follow-up voxelwise analysis to test for associations between walking speed and FA across the white matter Tract-Based Spatial Statistics (TBSS) skeleton. The analyses revealed a significant association between global FA and walking speed, indicating higher white matter integrity in people with higher pace. Voxelwise analysis supported widespread significant associations. We also found a significant interaction between sex and subcortical brain age on number of daily steps, indicating younger-appearing brains in more physically active women, with no significant associations among men. These results provide insight into the intricate associations between different measures of brain and physical health in old age, and corroborate established public health advice promoting physical activity.

PMID:34330086 | DOI:10.1016/j.nicl.2021.102767

J Neurosurg Pediatr. 2021 Jul 30:1-7. doi: 10.3171/2021.2.PEDS2115. Online ahead of print.

ABSTRACT

OBJECTIVE: Given concerns about the potential long-term effects of concussion in young athletes, concussion prevention has become a major focus for amateur sports leagues. Athletes have been known to frequently use anti-inflammatory medications to manage injuries, expedite return to play, and treat concussion symptoms. However, the effects of baseline nonsteroidal anti-inflammatory drug (NSAID) use on the susceptibility to head injury and concussion remain unclear. This study aims to assess the effects of preinjury NSAID use on concussion incidence, severity, and recovery in young athletes.

METHODS: Data from 25,815 ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing) tests were obtained through a research agreement with ImPACT Applications Inc. Subjects ranged in age from 12 to 22 years old. Those who reported NSAID use at baseline were assigned to one (anti-inflammatory [AI]) cohort, whereas all others were assigned to the control (CT) cohort. Differences in head trauma and concussion incidence, severity, and recovery were assessed using chi-square tests, unpaired t-tests, and Kaplan-Meier plots.

RESULTS: The CT cohort comprised a higher percentage (p < 0.0001) of males (66.30%) than the AI cohort (44.16%) and had a significantly greater portion of athletes who played football (p = 0.004). However, no statistically significant differences were found between the two cohorts in terms of the incidence of head trauma (CT = 0.489, AI = 0.500, p = 0.9219), concussion incidence (CT = 0.175, AI = 0.169, p = 0.7201), injury severity, or median concussion recovery time (CT = 8, AI = 8, p = 0.6416). In a multivariable analysis controlling for baseline differences between the cohorts, no association was found between NSAID use and concussion incidence or severity.

CONCLUSIONS: In this analysis, the authors found no evidence that preinjury use of NSAIDs affects concussion risk in adolescent athletes. They also found no indication that preinjury NSAID use affects the severity of initial injury presentation or concussion recovery.

PMID:34330088 | DOI:10.3171/2021.2.PEDS2115