Nevin Manimala

J Prosthodont. 2023 May 19. doi: 10.1111/jopr.13716. Online ahead of print.

ABSTRACT

PURPOSE: To compare screw surface characteristics between hemi-engaging and non-engaging implant-supported fixed partial denture (FPD) designs after cyclic loading.

MATERIALS AND METHODS: Twenty-four implants measuring 4.3 × 10mm were mounted on acrylic resin blocks. Specimens were divided into 2 groups. An experimental group included twelve 3-unit FPD with a hemi-engaging design; a control group included twelve 3-unit FPD with the conventional design of two non-engaging abutments. Both groups were subjected to two types of cycling loading (CL), first axial loading, and then lateral loading at 30°. Load was applied to the units one million times (1.0×10⁶ cycles) for each loading axis. Data on screw surface roughness in three locations and screw thread depth were collected before (BL) and after (AL) each loading type. Screw surface roughness was measured in μm using a mechanical digital surface profilometer and optical profiler. To evaluate screw thread depth in μm, an upright optical microscope Axio-imager 2 was used. To confirm readings made from the optical microscope, four random samples were selected from each group for scanning electron microscopy (SEM) analysis. The effect of cyclic loading was evaluated by averaging values across the two screws within each specimen, then calculating difference scores (DL) between BL and AL (DL = AL – BL). Additional difference scores were computed between the non-engaging screws in each experimental group specimen, and one randomly selected non-engaging screw in each control specimen. This difference was referred to as the non-engaging DL. Statistical significance was assessed using Mann-Whitney U tests (α = .05).

RESULTS: Comparisons of DL and non-engaging DL by loading type revealed one significant difference regarding surface roughness at the screw thread. Significantly greater mean changes were observed after axial loading compared to lateral loading regarding both DL (axial M = -0.36 ± 0.08; lateral M = -0.21 ± 0.09; U = 20; p = .003) and non-engaging DL (axial M = -0.40 ± 0.22; lateral M = -0.21 ± 0.11; U = 29; p = .013). No significant differences in screw surface roughness in other sites or thread depth were found between the experimental and control abutment designs in DL or in non-engaging DL. No significant differences were found for DL (axial U = 13, P = .423; lateral U = 9, P = .150;) or non-engaging DL (axial U = 13, P = .423; lateral U = 18, P = 1.00).

CONCLUSIONS: Results suggest that overall, changes in screw surface physical characteristics did not differ between hemi-engaging and non-engaging designs after evaluating screw surface roughness and thread depth before and after axial and lateral cyclic loading. This article is protected by copyright. All rights reserved.

PMID:37208973 | DOI:10.1111/jopr.13716

Ophthalmic Physiol Opt. 2023 May 19. doi: 10.1111/opo.13165. Online ahead of print.

ABSTRACT

PURPOSE: Refractions based on the optimisation of single-value wavefront-derived metrics may help determine appropriate corrections for individuals with Down syndrome where clinical techniques fall short. This study compared dioptric differences between refractions obtained using standard clinical techniques and two metric-optimised methods: visual Strehl ratio (VSX) and pupil fraction tessellated (PFSt), and investigated characteristics that may contribute to the differences between refraction types.

METHODS: Thirty adults with Down syndrome (age = 29 ± 10 years) participated. Three refractive corrections (VSX, PFSt and clinical) were determined and converted to vector notation (M, J₀ , J₄₅ ) to calculate the dioptric difference between pairings of each type using a mixed model repeated measures approach. Linear correlations and multivariable regression were performed to examine the relationship between dioptric differences and the following participant characteristics: higher order root mean square (RMS) for a 4 mm pupil diameter, spherical equivalent refractive error and Vineland Adaptive Behavior Scales (a measure of developmental ability).

RESULTS: The least squares mean estimates (standard error) of the dioptric differences for each pairing were as follows: VSX versus PFSt = 0.51 D (0.11); VSX versus clinical = 1.19 D (0.11) and PFSt versus clinical = 1.04 D (0.11). There was a statistically significant difference in the dioptric differences between the clinical refraction and each of the metric-optimised refractions (p < 0.001). Increased dioptric differences in refraction were correlated with increased higher order RMS (R = 0.64, p < 0.001 [VSX vs. clinical] and R = 0.47, p < 0.001 [PFSt vs. clinical]) as well as increased myopic spherical equivalent refractive error (R = 0.37, p = 0.004 [VSX vs. clinical] and R = 0.51, p < 0.001 [PFSt vs. clinical]).

CONCLUSIONS: The observed differences in refraction demonstrate that a significant portion of the refractive uncertainty is related to increased higher order aberrations and myopic refractive error. Methodology surrounding clinical techniques and metric-optimisation based on wavefront aberrometry may explain the difference in refractive endpoints.

PMID:37208971 | DOI:10.1111/opo.13165

J Healthc Risk Manag. 2023 May 19. doi: 10.1002/jhrm.21542. Online ahead of print.

ABSTRACT

As supply chains experienced disruptions early in the COVID-19 pandemic, personal protective equipment (PPE) quickly became scarce. The purpose of this study was to examine the impact of perceptions of inadequate PPE, fear of COVID-19 infection, and self-reported direct COVID-19 exposure on health care workers. Data to assess distress, resilience, social-ecological factors, and work and nonwork-related stressors were collected from June to July 2020 at a large medical center. Stressors were analyzed by role using descriptive statistics and multivariate regression analysis. Our data indicate that job role influenced fear of infection and perceptions of inadequate PPE in the early phase of the COVID-19 pandemic. Perceived organizational support was also related to perceptions of inadequate PPE supply. Interestingly, work location, rather than job role, was predictive of direct COVID-19 exposure. Our data highlight a disconnect between the perception of safety in the health care setting with real risk of exposure to infectious disease. This study suggests that leaders in health care should focus on cultivating supportive organizational cultures, assessing both perceived and actual safety, and provide adequate training in safety practices may improve preparedness and organizational trust during times of both certainty and crisis particularly for clinical workers with less education and training.

PMID:37208959 | DOI:10.1002/jhrm.21542

Bioinformatics. 2023 May 4;39(5):btad324. doi: 10.1093/bioinformatics/btad324.

NO ABSTRACT

PMID:37208919 | DOI:10.1093/bioinformatics/btad324

Health Serv Res. 2023 May 19. doi: 10.1111/1475-6773.14183. Online ahead of print.

ABSTRACT

OBJECTIVE: To examine if income inequality, social cohesion, and neighborhood walkability are associated with physical activity among rural adults.

DATA SOURCE: Cross-sectional data came from a telephone survey (August 2020-March 2021) that examined food access, physical activity, and neighborhood environments across rural counties in a southeastern state.

STUDY DESIGN: Multinomial logistic regression models assessed the likelihood of being active versus inactive and insufficiently active versus inactive in this rural population. Coefficients are presented as relative risk ratios (RRRs). Statistical significance was determined using 95% confidence intervals (CIs). All analyses were performed in STATA 16.1.

DATA COLLECTION/EXTRACTION METHODS: Trained university students administered the survey. Students verbally obtained consent, read survey items, and recorded responses into Qualtrics software. Upon survey completion, respondents were mailed a $10 incentive card and printed informed consent form. Eligible participants were ≥18 years old and current residents of included counties.

PRINCIPAL FINDINGS: Respondents in neighborhoods with relatively high social cohesion versus low social cohesion were more likely to be active than inactive (RRR = 2.50, 95% CI: 1.27-4.90, p < 0.01), after accounting for all other variables in the model. Income inequality and neighborhood walkability were not associated with different levels of physical activity in the rural sample.

CONCLUSIONS: Study findings contribute to limited knowledge on the relationship between neighborhood environmental contexts and physical activity among rural populations. The health effects of neighborhood social cohesion warrant more attention in health equity research and consideration when developing multilevel interventions to improve the health of rural populations.

PMID:37208903 | DOI:10.1111/1475-6773.14183

Med Sci Monit. 2023 May 20;29:e940355. doi: 10.12659/MSM.940355.

ABSTRACT

BACKGROUND Improving the quality of life of scoliosis patients with appropriate preventive measures is critical. This study aimed to investigate the relationships among bone mass, Cobb angle, and complete blood count (CBC) parameters in patients with scoliosis. MATERIAL AND METHODS This joint study was conducted by the pediatric department and orthopedics clinics, which used the medical records of patients aged 10-18 years between 2018 and 2022. Patients were divided into 3 groups according to the Cobb angle. Patient blood count levels from medical records and bone mineral density (BMD) Z scores (g/cm²) were compared among groups. Notably, BMD Z scores were calculated using a (BMD) dataset from local Turkish children after adjusting for height and age. RESULTS A total of 184 individuals (120 females, 64 males) were included in the study. There were statistically significant differences among the groups in platelet-to-lymphocyte ratio (PLR). Significant differences in DXA Z scores among groups were found. There was a significantly strong and positive correlation between DXA Z scores and all CBC parameters in patients with severe scoliosis. CONCLUSIONS This study found that CBC parameters can predict BMD in adolescents. Furthermore, the association between vitamin D deficiency and low BMD may contribute to the follow-up of body adaptation in patients with scoliosis receiving conservative treatment.

PMID:37208892 | DOI:10.12659/MSM.940355

Am Surg. 2023 May 19:31348231177922. doi: 10.1177/00031348231177922. Online ahead of print.

ABSTRACT

INTRODUCTION: Venous thromboembolism (VTE) is a source of preventable morbidity and mortality in critically ill trauma patients. Age is one independent risk factor. Geriatric patients embody a population at high thromboembolic and hemorrhagic risk. Currently, there is little guidance between low molecular weight heparin (LMWH) and unfractionated heparin (UFH) for anticoagulant prophylaxis in the geriatric trauma patient.

METHODS: A retrospective review was conducted at an ACS verified, Level I Trauma center from 2014 to 2018. All patients 65 years or older, with high-risk injuries and admitted to the trauma service were included. Choice of agent was at provider discretion. Patients in renal failure, or those that received no chemoprophylaxis, were excluded. The primary outcomes were the diagnosis of deep vein thrombosis or pulmonary embolism and bleeding associated complications (gastrointestinal bleed, TBI expansion, hematoma development).

RESULTS: This study evaluated 375 subjects, 245 (65%) received enoxaparin and 130 (35%) received heparin. DVT developed in 6.9% of UFH patients, compared to 3.3% with LMWH (P = .1). PE was present in 3.8% of UFH group, but only .4% in the LMWH group (P = .01). Combined rate of DVT/PE was significantly lower (P = .006) with LMWH (3.7%) compared to UFH (10.8%). 10 patients had documented bleeding events, and there was no significant association between bleeding and the use of LMWH or UFH.

CONCLUSIONS: VTE events are more common in geriatric patients treated with UFH compared to LMWH. There was no associated increase in bleeding complications when LMWH was utilized. LMWH should be considered the chemoprophylatic agent of choice in high risk geriatric trauma patients.

PMID:37208855 | DOI:10.1177/00031348231177922

Pharmacoepidemiol Drug Saf. 2023 May 19. doi: 10.1002/pds.5639. Online ahead of print.

ABSTRACT

PURPOSE: Propensity score weighting is a popular approach for estimating treatment effects using observational data. Different sets of propensity score-based weights have proposed, including inverse probability of treatment (IPT) weights whose target estimand is the average treatment effect (ATE), weights whose target estimand is the average treatment effect in the treated (ATT), and, more recently, matching weights, overlap weights, and entropy weights. These latter three sets of weights focus on estimating the effect of treatment in those subjects for whom there is clinical equipoise. We conducted a series of simulations to explore differences in the value of the target estimands for these five sets of weights when the difference in means is the measure of treatment effect.

METHODS: We considered 648 scenarios defined by different values of the prevalence of treatment, the c-statistic of the propensity score model, the correlation between the linear predictors for treatment selection and the outcome, and by the magnitude of the interaction between treatment status and the linear predictor for the outcome in the absence of treatment.

RESULTS: We found that, when the prevalence of treatment was low or high and the c-statistic of the propensity score model was moderate to high, that matching weights, overlap weights, and entropy weights had target estimands that differed meaningfully from the target estimand of the ATE weights.

CONCLUSIONS: Researchers using matching weights, overlap weights, and entropy weights should not assume that the estimated treatment effect is comparable to the ATE. This article is protected by copyright. All rights reserved.

PMID:37208837 | DOI:10.1002/pds.5639

J Dent Educ. 2023 May 19. doi: 10.1002/jdd.13246. Online ahead of print.

ABSTRACT

PURPOSE/OBJECTIVES: Developing time management is an important aspect of a dental student’s passage to clinical care and in their growth as a professional. Suitable time management and preparedness can potentially impact the prognosis of a successful dental appointment. The objective of this study was to determine if a time management exercise could be effective to increase students’ preparedness, organization, time management, and reflection during simulated clinical care prior to transitioning to the dental clinic.

METHODS: Students completed five-time management exercises during the term preceding their entrance into the predoctoral restorative clinic which included appointment planning and organization, and reflection once finished. Pre- and post-term surveys were used to determine the impact of the experience. Quantitative data was analyzed using a paired t-test and the qualitative data was thematically coded by the researchers.

RESULTS: Students reported a statistically significant increase in their self-confidence of clinical readiness after completion of the time management series, and all students completed the surveys. The themes indicated by students through their comments in the post-survey question regarding the experience were as follows: planning and preparation, time management, the practice of procedures, concern about workload, faculty encouragement, and unclear. Most students also reported the exercise to be beneficial for their predoctoral clinical appointments.

CONCLUSIONS: It was determined that the time management exercises were effective for the students as they transitioned to treating patients in the predoctoral clinic and can be used for future classes to increase their success.

PMID:37208799 | DOI:10.1002/jdd.13246

J Chem Inf Model. 2023 May 19. doi: 10.1021/acs.jcim.3c00460. Online ahead of print.

ABSTRACT

While polymerization-induced self-assembly (PISA) has become a preferred synthetic route toward amphiphilic block copolymer self-assemblies, predicting their phase behavior from experimental design is extremely challenging, requiring time and work-intensive creation of empirical phase diagrams whenever self-assemblies of novel monomer pairs are sought for specific applications. To alleviate this burden, we develop here the first framework for a data-driven methodology for the probabilistic modeling of PISA morphologies based on a selection and suitable adaption of statistical machine learning methods. As the complexity of PISA precludes generating large volumes of training data with in silico simulations, we focus on interpretable low variance methods that can be interrogated for conformity with chemical intuition and that promise to work well with only 592 training data points which we curated from the PISA literature. We found that among the evaluated linear models, generalized additive models, and rule and tree ensembles, all but the linear models show a decent interpolation performance with around 0.2 estimated error rate and 1 bit expected cross entropy loss (surprisal) when predicting the mixture of morphologies formed from monomer pairs already encountered in the training data. When considering extrapolation to new monomer combinations, the model performance is weaker but the best model (random forest) still achieves highly nontrivial prediction performance (0.27 error rate, 1.6 bit surprisal), which renders it a good candidate to support the creation of empirical phase diagrams for new monomers and conditions. Indeed, we find in three case studies that, when used to actively learn phase diagrams, the model is able to select a smart set of experiments that lead to satisfactory phase diagrams after observing only relatively few data points (5-16) for the targeted conditions. The data set as well as all model training and evaluation codes are publicly available through the GitHub repository of the last author.

PMID:37208794 | DOI:10.1021/acs.jcim.3c00460