Nevin Manimala

Phys Chem Chem Phys. 2021 Sep 14;23(34):18268-18282. doi: 10.1039/d1cp02654b. Epub 2021 Aug 24.

ABSTRACT

This perspective article provides a comprehensive but organized tutorial introduction of the kinetics related to photon upconversion (UC) by triplet-triplet annihilation (TTA) (TTA-UC). The field of TTA-UC is multi-disciplinary and rapidly growing with the involvement of researchers from diverse backgrounds. TTA-UC consists of a series of tangled photophysical processes, so a solid understanding of the kinetic features and consequences is important to develop and evaluate materials for TTA-UC. This tutorial starts with an introduction of the standard model of TTA-UC along with the assumptions used in the model. The essential concept of the spin statistics for TTA and how this concept is related to the singlet branching ratio, which directly affects the efficiency of UC, are then explained through step-by-step analyses. Using these foundations, solutions for the steady-state behaviors are derived, featuring the universal curve that describes the excitation intensity dependence of the UC quantum yield for any sample type. Various useful functions for analyzing experimental data are also introduced and summarized. The transient behaviors of TTA-UC are then discussed along with their equations, and the usefulness for analyzing transient experimental data is explained using examples. In this article, self-consistent derivations and relevant references are provided for an easy understanding of the advanced discussion and analyses.

PMID:34612372 | DOI:10.1039/d1cp02654b

J Int Neuropsychol Soc. 2021 Oct 6:1-8. doi: 10.1017/S1355617721001089. Online ahead of print.

ABSTRACT

OBJECTIVE: To evaluate the properties of the cognitive battery used in the MIND Diet Intervention to Prevent Alzheimer’s Disease. The MIND Diet Intervention is a randomized control trial to determine the relative effectiveness of the MIND diet in slowing cognitive decline and reducing brain atrophy in older adults at risk for Alzheimer’s dementia.

METHODS: The MIND cognitive function battery was administered at baseline to 604 participants of an average age of 70 years, who agreed to participate in the diet intervention study, and was designed to measure change over time. The battery included 12 cognitive tests, measuring the 4 cognitive domains of executive function, perceptual speed, episodic memory, and semantic memory. We conducted a principal component analysis to examine the consistency between our theoretical domains and the statistical performance of participants in each domain. To further establish the validity of each domain, we regressed the domain scores against a late-life cognitive activity score, controlling for age, race, sex, and years of education.

RESULTS: Four factors emerged in the principal component analyses that were similar to the theoretical domains. In regression equations, we found the expected associations with age, education, and late-life cognitive activity with each of the four cognitive domains.

CONCLUSIONS: These results indicate that the MIND cognitive battery is a comprehensive and valid battery of four separate domains of cognitive function that can be used in diet intervention trials for older adults.

PMID:34612190 | DOI:10.1017/S1355617721001089

Prep Biochem Biotechnol. 2021 Oct 6:1-11. doi: 10.1080/10826068.2021.1955710. Online ahead of print.

ABSTRACT

This study describes the hyaluronic acid (HA) production by S. zooepidemicus ATCC 43079, and the effect of the hyaluronidase enzyme on HA levels. The hyaluronidase production, glucose consumption, and lactate formation were recorded during fermentation. The HA production, and productivity at different amounts of glucose, yeast extract and pH were evaluated by response surface statistical approach in presence of 6-O-palmytoil-l-ascorbic acid as a chemical inhibitor for biocatalyst hyaluronidase. Under optimum conditions, HA production was increased two-fold from 190 ± 17 mg L^-1 in basal medium to 384.6 ± 7.5 mg L^-1 in the optimized medium containing enzyme inhibitor. Furthermore, the results indicated that the chemical inhibitor could suppress the biocatalyst activity and prevent the HA loss at the end of the exponential phase of S. zooepidemicus ATCC 43079.

PMID:34612172 | DOI:10.1080/10826068.2021.1955710

Int J Inj Contr Saf Promot. 2021 Oct 6:1-10. doi: 10.1080/17457300.2021.1983844. Online ahead of print.

ABSTRACT

Crash hot spot identification and prediction using spatial statistics and random forest methods on the interstate of Michigan are evaluated. The Getis-Ord statistics are adopted to identify hot spots using location, frequency, and equivalent property damage only weights computed from the cost and severity of crashes. In the random forest approach, data patterns between 2010 and 2017 are determined to predict hot spots of crashes in 2018. Accordingly, the results indicate that: (i) interstate routes have witnessed 13,089 crashes on significant hot spots, 7,413 on cold spots, and the rest in other locations; (ii) random forest shows 76.7% and 74% accuracy for validation and prediction, respectively. The performance of the model is further affirmed with precision, recall, and F-scores of 75%, 74%, and 70%, respectively; and (iii) clustering of the crashes exhibits spatial dependence of high and low equivalent property damage only crashes. The practical significance of the approach is highlighted in the identification and prediction of hot spots.

PMID:34612168 | DOI:10.1080/17457300.2021.1983844

Expert Rev Vaccines. 2021 Oct 6. doi: 10.1080/14760584.2021.1990045. Online ahead of print.

ABSTRACT

BACKGROUND: COVID-19 pandemic has disrupted health services, including vaccination demand. We describe the impact of the COVID-19 pandemic on routine pediatric vaccination in Brazil.

METHODS: We conducted a retrospective analysis of all vaccine doses provided to children aged 0-6 years from January 2019 to December 2020. We obtained data stratified by age group (0 to 2 years and >2 to 6 years) and Brazilian region. Difference-in-difference (DiD) analyses were performed to compare vaccine uptake in the pre-pandemic (January-February), stay-at-home (March-June), and reopening (July-December) periods.

RESULTS: The number of vaccine doses administered declined in the stay-at-home period. For children aged 0 to 2 years, the highest reductions were recorded in the North (-25.3%), Northeast (-16.8%) and Central-West (-10.2%) regions. For children aged >2 to 6 years, the highest decline was observed in the North (DiD = -27.2%) and South (DiD = -14.0%) regions. The number of vaccine doses administered in the reopening period has slightly increased in all regions.

CONCLUSIONS: Vaccination decreased during the COVID-19 pandemic. Although the number of doses recovered in part during the reopening phase, additional strategies, such as increased public awareness and vaccination booster campaigns are required.

PMID:34612135 | DOI:10.1080/14760584.2021.1990045

Expert Rev Med Devices. 2021 Oct 6. doi: 10.1080/17434440.2021.1990037. Online ahead of print.

ABSTRACT

BACKGROUND: The successful application of Machine Learning (ML) to many clinical problems can lead to its implementation as medical devices (MD), being important to assess the associated risks.

METHODS: An anemia control model (ACM), certified as MD may face adverse events as the result of wrong predictions that are translated into suggestions of doses of erythropoietic stimulating agents to dialysis patients. Risks are assessed as the combination of severity and probability of a given hazard. While severities are typically assessed by clinicians, probabilities are tightly related to the performance of the predictive model.

RESULTS: A post-marketing dataset formed by all adult patients registered in French, Portuguese and Spanish clinics, belonging to an international network was considered; 3876 patients and 11508 suggestions were eventually included. The achieved results show that there are no statistical differences between the probabilities of adverse events that are estimated in the ACM test set (using only Spanish clinics) and those actually observed in the post-marketing cohort.

CONCLUSIONS: The risks of an ACM-MD can be accurately and robustly estimated, thus enhancing patients’ safety. The proposed methodology is applicable to other clinical decisions based on predictive models since our proposal does not depend on the particular predictive model.

PMID:34612120 | DOI:10.1080/17434440.2021.1990037

Connect Tissue Res. 2021 Oct 6:1-13. doi: 10.1080/03008207.2021.1982915. Online ahead of print.

ABSTRACT

BACKGROUND: We aimed to investigate the effectiveness of docosahexaenoic acid (DHA) as a treatment for Achilles tendinopathy (AT) induced with type-I collagenase in rats and compare it with collagen.

METHODS: The AT model was induced with type I collagenase, and animals were randomly assigned to groups. Group 1:AT, Group 2: Collagen (7.2 mg/kg/day), Group 3:DHA (300 mg/kg/day), and Group 4:DHA (100 mg/kg/day). Right tendons of Group1 were used as a healthy control (HC). Oral treatments were applied for eight weeks. Serum tumor necrosis factor-alpha(TNF-α), matrix metalloproteinase-13 (MMP-13), and interleukin-1 beta(IL-1β) concentrations were determined by ELISA. Tendon samples were taken for histopathological evaluation and examined immunohistochemically with antibodies specific for Col1A1, TNF-α, MMP-13, IL-1β, and nitric oxide synthase-2(NOS-2). The ultimate tensile force (UTF) yield force(YF) and stiffness were measured by biomechanical assessments.

RESULTS: UTF,YF and stiffness values were increased in all treatment groups compared to the AT control, a significant increase was found in Group 2 (p < 0.05). There was severe degeneration of tendon cells in the AT control. The tendon cells in samples from Groups 2-3 were less degraded, and this was statistically significant (p < 0.05). TNF-α, MMP-13, IL-1β, and NOS-2 expressions were significantly higher in the AT control compared to the HC. In all treatment groups, their concentrations were lower than in the AT control. Serum TNF-α, MMP-13, and IL-1β levels were lower in all treatment groups (Especially in Group3 (p < 0.001)) compared to Group1.

CONCLUSION: The efficacy of high-dose DHA as a treatment for AT was investigated from biochemical, histopathological, and biomechanical perspectives. The results showed that DHA could be an alternative treatment compound to collagen.

PMID:34612118 | DOI:10.1080/03008207.2021.1982915

Mult Scler. 2021 Oct 6:13524585211049397. doi: 10.1177/13524585211049397. Online ahead of print.

ABSTRACT

BACKGROUND: The Symbol Digit Modalities Test (SDMT) is increasingly utilized in clinical trials. A SDMT score change of 4 points is considered clinically important, based on association with employment anchors. Optimal thresholds for statistically reliable SDMT changes, accounting for test reliability and measurement error, are yet to be applied to individual cases.

OBJECTIVE: The aim of this study was to derive a statistically reliable marker of individual change on the SDMT.

METHODS: This prospective, case-control study enrolled 166 patients with multiple sclerosis (MS). SDMT scores at baseline, relapse, and 3-month follow-up were compared between relapsing and stable patient groups. Using data from the stable group and three previously published studies, candidate thresholds for reliable decline were calculated and validated against other tests and a clinically meaningful anchor-cognitive relapse.

RESULTS: Candidate thresholds for reliable decline at the 80% confidence level varied between 6 and 11 points. An SDMT change of 8 or more raw score points was deemed to offer the best balance of discriminatory power and external validity for estimating cognitive decline.

CONCLUSION: This study illustrates the feasibility and usefulness of reliable change methodology for identifying statistically meaningful cognitive decline that could be implemented to identify change in individual patients, for both clinical management and clinical trial outcomes.

PMID:34612114 | DOI:10.1177/13524585211049397

Mult Scler. 2021 Oct 6:13524585211048401. doi: 10.1177/13524585211048401. Online ahead of print.

ABSTRACT

BACKGROUND: Few studies have addressed the results of educational efforts concerning proper use of McDonald criteria (MC) revisions outside multiple sclerosis (MS) subspecialty centers. Neurology residents and MS subspecialist neurologists demonstrated knowledge gaps for core elements of the MC in a recent prior study.

OBJECTIVE: To assess comprehension and application of MC core elements by non-MS specialist neurologists in the United States who routinely diagnose MS.

METHODS: Through a cross-sectional study design, a previously developed survey instrument was distributed online.

RESULTS: A total of 222 neurologists completed the study survey. Syndromes atypical for MS were frequently incorrectly considered “typical” MS presentations. Fourteen percent correctly identified definitions of both “periventricular” and “juxtacortical” lesions and 2% correctly applied these terms to 9/9 images. Twenty-four percent correctly identified all four central nervous system (CNS) regions for satisfaction of magnetic resonance imaging (MRI) dissemination in space. In two presented cases, 61% and 71% correctly identified dissemination in time (DIT) was not fulfilled, and 85% and 86% subsequently accepted nonspecific historical symptoms without objective evidence for DIT fulfillment.

CONCLUSION: The high rate of knowledge deficiencies and application errors of core elements of the MC demonstrated by participants in this study raise pressing questions concerning adequacy of dissemination and educational efforts upon publication of revisions to MC.

PMID:34612110 | DOI:10.1177/13524585211048401

Ann Med. 2021 Dec;53(1):1520-1530. doi: 10.1080/07853890.2021.1970219.

ABSTRACT

OBJECTIVE: During the COVID-19 pandemic, emergency medicine (EM) teachers had to employ innovative methods to ensure the continuity of the education process. The purpose of this study was to explore the adequacy of the 360-degree video (video 360) technology in EM education in the context of: (a) students’ attitudes towards the video 360; (b) students’ academic performance in their required examination at the end of the EM course compared to the assessment results of students from the previous academic year.

METHODS: A mixed-method research project enrolled the fourth-year medical students who attended the required EM course during the first semester of the academic year 2020-2021 when all activities with undergraduate students went online and teaching scenarios recorded in the video 360 format were employed. Data collection was two-fold: (a) anonymous questionnaires, complemented with basic YouTube analytics; (b) multiple-choice questionnaires (MCQ) and oral examination, contrasting the results with those in 2019-2020. Data analysis used descriptive statistics and non-parametric methods.

RESULTS: Seventy-nine students (53 females and 26 males) participated in the project and all completed the EM course. Students’ interest in and their acceptance of the video 360 technology were high (total scoring in the upper 20% of the respective scales), with consistently good performance in two parallel, independent, interview-based oral/practical evaluations (Spearman correlation coefficient R = 0.665, p < .001). The majority scored over 90% in the summative MCQ, with higher values compared to their colleagues’ during the previous academic year (with on-site teaching): scoring percentages with mean ± standard deviation of 92.52 ± 4.57 and 76.67 ± 18.77, respectively.

CONCLUSION: Our project showed that the video 360 scenarios were effective in teaching EM. In the long term, employing this accessible and inexpensive educational approach would add value to on-site training by enriching the exposure to a specific ED environment.KEY MESSAGESMedical students valued the 360-degree video scenarios as contributing substantially to their EM knowledge and preparedness.Examination results confirmed the 360-degree video scenarios as viable in EM teaching.The 360-degree video technology would be a sustainable solution for hybrid medical teaching in the long term.

PMID:34612105 | DOI:10.1080/07853890.2021.1970219