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  1. Turkyilmaz I, Abdullah JY, Wilkins GN, Bernardi S, Varvara G
    Minerva Dent Oral Sci, 2024 Nov 20.
    PMID: 39565339 DOI: 10.23736/S2724-6329.24.04898-8
    BACKGROUND: The purpose of this study was to determine the accuracy of an intraoral scanner to digitally duplicate complete dentures and analyze the effects of mesh reduction of digital files on the surface area and volume accuracy of complete dentures, in vitro.

    METHODS: A mandibular complete denture was scanned by a desktop scanner to create a digital STL reference file (control). Fifteen identical scans were created by using an intraoral scanner and exported as STL files (test group). These 15 files were saved at 100% of the original scan resolution then reduced to 75%, 50%, 25%, and 10% of their original quality. These 75 scans were statistically analyzed by calculating The Hausdorff Distance (HD) and Dice Similarity Coefficients (DSC) to assess the variation between the mean reduced intraoral scanner files test and the control desktop scanner file and eventual inconsistencies. The volumes of the reduced mesh files were also compared with the 100% resolution intraoral mesh files to evaluate precision and trueness of the intraoral scanner.

    RESULTS: Reduced mesh files of 10%, 25%, 50%, 75% of the original scan yielded a percentage similarity average of 99.7%, indicating a very high precision value for the intraoral scanner. Also, the volumes of each associated mesh reduction slightly decreased with non-statistically significant results.

    CONCLUSIONS: This study concluded that the chosen intraoral scanner for this study provided very high trueness (98.34%) and precision (99.7%), and also the volumes of reduced mesh files slightly decreased but were not statistically significant.

  2. Bauer M, Glenn T, Achtyes ED, Alda M, Agaoglu E, Altınbaş K, et al.
    Int J Bipolar Disord, 2021 Sep 01;9(1):26.
    PMID: 34467430 DOI: 10.1186/s40345-021-00231-7
    BACKGROUND: Bipolar disorder is associated with circadian disruption and a high risk of suicidal behavior. In a previous exploratory study of patients with bipolar I disorder, we found that a history of suicide attempts was associated with differences between winter and summer levels of solar insolation. The purpose of this study was to confirm this finding using international data from 42% more collection sites and 25% more countries.

    METHODS: Data analyzed were from 71 prior and new collection sites in 40 countries at a wide range of latitudes. The analysis included 4876 patients with bipolar I disorder, 45% more data than previously analyzed. Of the patients, 1496 (30.7%) had a history of suicide attempt. Solar insolation data, the amount of the sun's electromagnetic energy striking the surface of the earth, was obtained for each onset location (479 locations in 64 countries).

    RESULTS: This analysis confirmed the results of the exploratory study with the same best model and slightly better statistical significance. There was a significant inverse association between a history of suicide attempts and the ratio of mean winter insolation to mean summer insolation (mean winter insolation/mean summer insolation). This ratio is largest near the equator which has little change in solar insolation over the year, and smallest near the poles where the winter insolation is very small compared to the summer insolation. Other variables in the model associated with an increased risk of suicide attempts were a history of alcohol or substance abuse, female gender, and younger birth cohort. The winter/summer insolation ratio was also replaced with the ratio of minimum mean monthly insolation to the maximum mean monthly insolation to accommodate insolation patterns in the tropics, and nearly identical results were found. All estimated coefficients were significant at p 

  3. Bauer M, Glenn T, Achtyes ED, Alda M, Agaoglu E, Altınbaş K, et al.
    J Psychosom Res, 2022 Sep;160:110982.
    PMID: 35932492 DOI: 10.1016/j.jpsychores.2022.110982
    OBJECTIVE: Circadian rhythm disruption is commonly observed in bipolar disorder (BD). Daylight is the most powerful signal to entrain the human circadian clock system. This exploratory study investigated if solar insolation at the onset location was associated with the polarity of the first episode of BD I. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area of the Earth.

    METHODS: Data from 7488 patients with BD I were collected at 75 sites in 42 countries. The first episode occurred at 591 onset locations in 67 countries at a wide range of latitudes in both hemispheres. Solar insolation values were obtained for every onset location, and the ratio of the minimum mean monthly insolation to the maximum mean monthly insolation was calculated. This ratio is largest near the equator (with little change in solar insolation over the year), and smallest near the poles (where winter insolation is very small compared to summer insolation). This ratio also applies to tropical locations which may have a cloudy wet and clear dry season, rather than winter and summer.

    RESULTS: The larger the change in solar insolation throughout the year (smaller the ratio between the minimum monthly and maximum monthly values), the greater the likelihood the first episode polarity was depression. Other associated variables were being female and increasing percentage of gross domestic product spent on country health expenditures. (All coefficients: P ≤ 0.001).

    CONCLUSION: Increased awareness and research into circadian dysfunction throughout the course of BD is warranted.

  4. Bauer M, Glenn T, Achtyes ED, Alda M, Agaoglu E, Altınbaş K, et al.
    Int J Bipolar Disord, 2023 Jun 22;11(1):22.
    PMID: 37347392 DOI: 10.1186/s40345-023-00303-w
    BACKGROUND: Sunlight contains ultraviolet B (UVB) radiation that triggers the production of vitamin D by skin. Vitamin D has widespread effects on brain function in both developing and adult brains. However, many people live at latitudes (about > 40 N or S) that do not receive enough UVB in winter to produce vitamin D. This exploratory study investigated the association between the age of onset of bipolar I disorder and the threshold for UVB sufficient for vitamin D production in a large global sample.

    METHODS: Data for 6972 patients with bipolar I disorder were obtained at 75 collection sites in 41 countries in both hemispheres. The best model to assess the relation between the threshold for UVB sufficient for vitamin D production and age of onset included 1 or more months below the threshold, family history of mood disorders, and birth cohort. All coefficients estimated at P ≤ 0.001.

    RESULTS: The 6972 patients had an onset in 582 locations in 70 countries, with a mean age of onset of 25.6 years. Of the onset locations, 34.0% had at least 1 month below the threshold for UVB sufficient for vitamin D production. The age of onset at locations with 1 or more months of less than or equal to the threshold for UVB was 1.66 years younger.

    CONCLUSION: UVB and vitamin D may have an important influence on the development of bipolar disorder. Study limitations included a lack of data on patient vitamin D levels, lifestyles, or supplement use. More study of the impacts of UVB and vitamin D in bipolar disorder is needed to evaluate this supposition.

  5. Ewers RM, Orme CDL, Pearse WD, Zulkifli N, Yvon-Durocher G, Yusah KM, et al.
    Nature, 2024 Jul;631(8022):808-813.
    PMID: 39020163 DOI: 10.1038/s41586-024-07657-w
    Logged and disturbed forests are often viewed as degraded and depauperate environments compared with primary forest. However, they are dynamic ecosystems1 that provide refugia for large amounts of biodiversity2,3, so we cannot afford to underestimate their conservation value4. Here we present empirically defined thresholds for categorizing the conservation value of logged forests, using one of the most comprehensive assessments of taxon responses to habitat degradation in any tropical forest environment. We analysed the impact of logging intensity on the individual occurrence patterns of 1,681 taxa belonging to 86 taxonomic orders and 126 functional groups in Sabah, Malaysia. Our results demonstrate the existence of two conservation-relevant thresholds. First, lightly logged forests (<29% biomass removal) retain high conservation value and a largely intact functional composition, and are therefore likely to recover their pre-logging values if allowed to undergo natural regeneration. Second, the most extreme impacts occur in heavily degraded forests with more than two-thirds (>68%) of their biomass removed, and these are likely to require more expensive measures to recover their biodiversity value. Overall, our data confirm that primary forests are irreplaceable5, but they also reinforce the message that logged forests retain considerable conservation value that should not be overlooked.
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