Στην βιολογία, το περιβάλλον μπορεί να καθοριστεί σαν ενα σύνολο κλιματικών, βιοτικών, κοινωνικών και εδαφικών παραγόντων που δρουν σε έναν οργανισμό και καθορίζουν την ανάπτυξη και την επιβίωση του. Έτσι, περιλαμβάνει οτιδήποτε μπορεί να επηρεάσει άμεσα τον μεταβολισμό ή τη συμπεριφορά των ζωντανών οργανισμών ή ειδών, όπως το φως, ο αέρας, το νερό, το έδαφος και άλλοι παράγοντες. Δείτε επίσης το άρθρο για το φυσικό περιβάλλον και τη φυσική επιλογή.
Στην αρχιτεκτονική, την εργονομία και την ασφάλεια στην εργασία, περιβάλλον είναι το σύνολο των χαρακτηριστικών ενός δωματίου ή κτιρίου που επηρεάζουν την ποιότητα ζωής και την αποδοτικότητα, περιλαμβανομένων των διαστάσεων και της διαρρύθμισης των χώρων διαβίωσης και της επίπλωσης, του φωτισμού, του αερισμού, της θερμοκρασίας, του θορύβου κλπ. Επίσης μπορεί να αναφέρεται στο σύνολο των δομικών κατασκευών. Δείτε επίσης το άρθρο για το δομημένο περιβάλλον.
Στην ψυχολογία, περιβαλλοντισμός είναι η θεωρία ότι το περιβάλλον (με τη γενική και κοινωνική έννοια) παίζει μεγαλύτερο ρόλο από την κληρονομικότητα καθορίζοντας την ανάπτυξη ενός ατόμου. Συγκεκριμένα, το περιβάλλον είναι ένας σημαντικός παράγοντας πολλών ψυχολογικών θεωριών.
Στην τέχνη, το περιβάλλον αποτελεί κινητήριο μοχλό και μούσα εμπνέοντας τους ζωγράφους ή τους ποιητές. Σε όλες τις μορφές της Τέχνης αποτελεί έμπνευση και οι Καλές Τέχνες φανερώνουν την επιρροή οπού άσκησε σε όλους τους καλλιτέχνες με όποιο είδος Τέχνης κι αν ασχολούνται. Ο άνθρωπος μέσα στο περιβάλλον δημιουργεί Μουσική, Ζωγραφική, Ποίηση, Γλυπτική, χορό, τραγούδι, θέατρο, αλλά και όλες οι μορφές τέχνης έχουν άμεση έμπνευση από το περιβάλλον.

Τρίτη 10 Ιανουαρίου 2023

A tooth‐supported titanium mesh bending and positioning module for alveolar bone augmentation and improving accuracy

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Objective

Guided bone regeneration with titanium mesh is a commonly used bone augmentation technique. However, deformation and sliding may occur during the installation of titanium mesh, which may lead to poor accuracy of bone augmentation. This article presented three cases, which describe a tooth-supported titanium mesh bending and positioning module aiming to improve the precision of bone augmentation.

Clinical Considerations

After designing the ideal bone increment volume digitally, print out the difference bone module between the ideal and existing bone mass and one or two wings. The wings are supported by the adjacent teeth to show the ideal bone mass in the patients' mouth. Finally, the titanium mesh is bent and installed in the ideal position by the module.

Conclusions

A favorable outcome has been preliminarily confirmed in these cases, the average vertical bone gain was 4.16 mm and the average horizontal gain was 7.48 mm after 6 months. Using the module in the treatment of patients with bone augmentation can effectively improve the accuracy, the maximum deviation was 1.5 mm and the mean was 0.6 mm.

Clinical Significance

This study improves the bone augmentation technology with titanium mesh. The titanium mesh is fixed in the ideal position, which facilitates subsequent implantation and denture repair.

View on Web

Δευτέρα 9 Ιανουαρίου 2023

Overall and abdominal obesity and risks of all-cause and cause-specific mortality

alexandrossfakianakis shared this article with you from Inoreader
Abstract
Background
Studies found a J-shaped association between body mass index (BMI) and mortality. However, it is unclear whether the association is driven by biases, particularly confounding by fat-free mass.
Methods
We conducted an individual-level pooled analysis of three cohorts of Korean adults (aged ≥ 40 years; n = 153 248). Mortality was followed up through December 2019. Anthropometric data were directly measured at baseline. Fat and fat-free mass were predicted using validated prediction models. Using Cox proportional hazards models, we estimated the associations of BMI and waist circumference (WC) with all-cause and cause-specific mortality. To account for biases, we excluded participants aged ≥ 70 years, deaths that occurred within 5 years of follow-up and ever smokers, and adjusted for fat-free mass index (FFMI).
Results
During the follow-up of up to 18 years, 6061 deaths were identified. We observed J-shaped association of BMI (nadir at 22–26) and monotonically positive association of WC with all-cause, cardiovascular, and cancer mortality among Korean adults without a history of cancer or cardiovascular disease. In the BMI analysis, excluding ever smokers and adjusting for FFMI attenuated the excess mortality in underweight participants and transformed the J-shaped association into a monotonically positive shape, suggesting an increased mortality at BMI > 22.0. Excluding participants aged ≥ 70 years and deaths that occurred within 5 years of follow-up did not change the results. In the WC analysis, the monotonic positive associations did not change after the control. Similar results were observed among participants with a history of cancer or cardiovascular disease.
Conclusions
Our data suggest that both overall and abdominal body fat are associated with increased mortality in Korean adults.
View on Web

Κυριακή 8 Ιανουαρίου 2023

Effect of sintering on the translucency of CAD‐CAM lithium disilicate restorations: a comparative in vitro study

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Purpose

The available independent data on the translucency of novel pre and fully sintered chair-side computer-aided design and computer-aided manufacturing (CAD-CAM) lithium disilicate are limited. This comparative in vitro study evaluated the translucency degree of pre and fully sintered chairside CAD-CAM lithium disilicate crowns after optional, required, and additional firing processes.

Materials and Methods

One hundred and five maxillary left central incisor crowns manufactured by three different CAD-CAM lithium disilicate brands shade A1 were assigned into 7 groups as follows (n = 15): (1) n!ce Straumann without sintering; (2) n!ce Straumann with one additional sintering process; (3) n!ce Straumann with two additional sintering processes; (4) Amber Mill with one sintering process; (5) Amber Mill with two sintering processes; (6) IPS e.max CAD with one sintering process; (7) IPS e.max CAD with two sintering processes. The translucency of all crowns was evaluated with a color imaging spectrophotometer. All statistical analyses were performed using statistical software. A standard level of significance was set at α < 0.05.

Results

All the milled crowns presented different degrees of translucency, and additional sintering processes altered it. IPS E.max CAD with two (4.33 ± 0.26) and one (4.01 ± 0.15) sintering processes displayed the highest translucency, whereas n!ce Straumann with no sintering process provided the lowest value (2.82 ± 0.16).

Conclusions

The translucency of chairside lithium disilicate single-unit full-coverage restorations manufactured with subtractive technology was significantly influenced by the brand and the number of sintering processes. The traditional presintered IPS e.max CAD and the fully crystallized glass-ceramic n!ce Straumann considerably increased the translucency after one additional firing process, whereas Amber Mill decreased its translucency.

This article is protected by copyright. All rights reserved

View on Web

Algorithmic dementia classification: promises and challenges

alexandrossfakianakis shared this article with you from Inoreader
Abstract
Dementia is a complex, progressive syndrome characterized by cognitive decline and disability. Gold-standard dementia diagnosis requires several hours of cognitive and clinical assessment and review by a panel of clinicians and is infeasible in large population-based cohort studies. Alternatively, algorithmic dementia classification methods, which use models that take measures of cognition and functional limitations into account or cognitive and functional limitation score cutoffs, have been developed to predict dementia status for participants in large studies. Developing accurate dementia classification algorithms is crucial for high-quality studies of the distribution and determinants of dementia. The article by Nichols et al. (Am J Epidemiol. XXXX;XXX(XX):XXXX–XXXX) assesses differences in associations of measures of cognition and functional limitations with prevalent versus incident dementia and discusses implications for algorithmic demen tia classification in research studies. This work highlights important opportunities for tailoring measures of cognition and functional limitations to study goals by selecting optimal measures and developing and validating algorithms specific to study needs. Combining efficient, high-quality assessments of cognition and functional limitations with innovative study designs will facilitate collection of higher quality measures in larger samples and support future development of accurate dementia classifications, ultimately leading to more impactful epidemiologic studies.
View on Web

Temporal trends in the incidence of malignant and non-malignant primary brain and central nervous system tumors by method of diagnosis in England, 1993-2017

alexandrossfakianakis shared this article with you from Inoreader
Abstract
Background
Several studies report increasing incidence of primary CNS tumors. The reasons for this are unclear.
Methods
Data on all 188,340 individuals diagnosed with a primary CNS tumor in England (1993-2017) were obtained from the National Cancer Registry. Data on all CT head and MRI brain scans in England (2013-2017) were obtained from NHS Digital. Age-sex-standardized annual incidence rates per 100,000 population (ASR) were calculated by calendar year, tumor behavior, tumor location and method of diagnosis. Temporal trends were quantified using average annual percent change (AAPC).
Results
The ASR for all CNS tumors increased from 13.0 in 1993 to 18.6 in 2017 (AAPC: 1.5%, 95% CI: 1.3, 1.7). The ASR for malignant tumors (52% overall) remained stable (AAPC: +0.5%, 95% CI: -0.2, 1.3), while benign tumors (37% overall) increased (AAPC: +2.6%, 95% CI: 1.2, 4.0). Among the 66% of benign tumors that were microscopically c onfirmed, the ASR increased modestly (AAPC: 1.3%, 95% CI: 0.5, 2.1). However, among the 25% of benign tumors that were radiographically confirmed, the ASR increased substantially (AAPC: 10.2%, 95% CI: 7.9, 12.5), principally driven by large increases in those aged 65+. The rate of CT head scans in Accident & Emergency (A&E) increased during 2013-2017, with especially large increases in 65-84 and 85+ year olds (AAPCs: 18.4% and 22.5%).
Conclusion
Increases in CNS tumor incidence in England are largely attributable to greater detection of benign tumors. This could be the result of increasing use of neuroimaging, particularly CT head scans in A&E in people aged 65+.
View on Web

Upregulation of PD‐L1 by SARS‐CoV‐2 promotes immune evasion

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Patients with severe COVID-19 often suffer from lymphopenia, which is linked to T cell sequestration, cytokine storm and mortality. However, it remains largely unknown how SARS-CoV-2 induces lymphopenia. Here, we studied the transcriptomic profile and epigenomic alterations involved in cytokine production by SARS-CoV-2-infected cells. We adopted a reverse time-order gene coexpression network (TO-GCN) approach to analyze time-series RNA-sequencing data, revealing epigenetic modifications at the late stage of viral egress. Furthermore, we identified SARS-CoV-2-activated NF-κB and IRF1 pathways contributing to viral infection and COVID-19 severity through epigenetic analysis of H3K4me3 ChIP-sequencing. Cross-referencing our transcriptomic and epigenomic datasets revealed that coupling NF-κB and IRF1 pathways mediate PD-L1 immunosuppressive programs. Interestingly, we observed higher PD-L1 expression in Omicron-infected cells than SARS-CoV-2 infected cells. Blocking PD-L1 at an earl y stage of virally-infected AAV-hACE2 mice significantly recovered lymphocyte counts and lowered inflammatory cytokine levels. Our findings indicate that targeting the SARS-CoV-2-mediated NF-κB and IRF1-PD-L1 axis may represent an alternative strategy to reduce COVID-19 severity.

This article is protected by copyright. All rights reserved.

View on Web