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Impact of intraoral scanner, scanning strategy, and scanned arch on the scan accuracy of edentulous arches: An in vitro study.
Get PDFSTATEMENT OF PROBLEM
The scanning strategy used when making complete arch digital scans affects the accuracy of the scan, and the accuracy of the strategy may be influenced by the scanner used. However, these effects have not been investigated thoroughly with complete arch edentulous scanning.
PURPOSE
The purpose of this in vitro study was to determine the effect of scanning strategies and the scanned arch on the accuracy of complete arch edentulous scans using 2 intraoral scanner (IOS) systems.
MATERIAL AND METHODS
Two IOSs were used (TRIOS 4 and Emerald S) to scan maxillary and mandibular typodonts using 6 scanning strategies (test scans), and conventional impressions of both arches were also made. By using a metrology software program, test scans were superimposed onto a reference scan, and the root mean square (RMS) of the absolute deviation values was calculated to express trueness. The sample with the best trueness was used as reference onto which the remaining samples from the same group were superimposed, and the RMS of the absolute deviation values was calculated to express precision. Statistical modeling was applied using the fixed effects models (α=.05).
RESULTS
The main effects of scanner and strategy significantly impacted the trueness RMS values (P<.001), with significant interactions between them (P=.012). The main effects of scanner, strategy, and arch significantly impacted the precision of RMS values (P=.004), (P=.033), and (P=.023). Conventional impressions and the TRIOS 4 scanner had comparable accuracy, while the Emerald S scanner was inferior to both. P-O-B had the highest overall accuracy and strategy ZZ had the worst. Better precision was found with the maxillary arch.
CONCLUSIONS
The scanner type and scanning strategy significantly impacted the accuracy of the digital scans of completely edentulous arches, with a significant interaction between scanner and strategy. The arch being scanned had a significant effect on scan precision but not on scan trueness
Rapid adaptation of recombining populations on tunable fitness landscapes.
Get PDFHow does standing genetic variation affect polygenic adaptation in recombining populations? Despite a large body of work in quantitative genetics, epistatic and weak additive fitness effects among simultaneously segregating genetic variants are difficult to capture experimentally or to predict theoretically. In this study, we simulated adaptation on fitness landscapes with tunable ruggedness driven by standing genetic variation in recombining populations. We confirmed that recombination hinders the movement of a population through a rugged fitness landscape. When surveying the effect of epistasis on the fixation of alleles, we found that the combined effects of high ruggedness and high recombination probabilities lead to preferential fixation of alleles that had a high initial frequency. This indicates that positively epistatic alleles escape from being broken down by recombination when they start at high frequency. We further extract direct selection coefficients and pairwise epistasis along the adaptive path. When taking the final fixed genotype as the reference genetic background, we observe that, along the adaptive path, beneficial direct selection appears stronger and pairwise epistasis weaker than in the underlying fitness landscape. Quantitatively, the ratio of epistasis and direct selection is smaller along the adaptive path (≈1) than expected. Thus, adaptation on a rugged fitness landscape may lead to spurious signals of direct selection generated through epistasis. Our study highlights how the interplay of epistasis and recombination constrains the adaptation of a diverse population to a new environment
Impact of progesterone on the immune system in women: a systematic literature review.
Get PDFPURPOSE
The immune system is influenced by many factors, including female sex hormones. The extent of this influence, however, is not completely understood so far. This systematic literature review aims at giving an overview of the existing concepts on how endogenous progesterone influences the female immune system along the menstrual cycle.
METHODS
The inclusion criteria were healthy female subjects in their reproductive age with a regular menstrual cycle. The exclusion criteria were exogenous progesterone, animal models, nonhealthy study populations and pregnancy. This led to 18 papers covered in this review. The search was performed using the databases EMBASE, Ovid MEDLINE and Epub, and the last search was conducted on September 18, 2020. Our findings were analyzed in four categories: cellular immune defense, humoral immune defense, objective and subjective clinical parameters.
RESULTS
We demonstrated that progesterone acts in an immunosuppressive way, favoring a Th-2-like cytokine profile. Further, we showed that progesterone inhibits mast cell degranulation and relaxes smooth muscle cells. Furthermore, we found supporting evidence for a so-called window of vulnerability after ovulation, where immune functions are lowered and mediated through progesterone.
CONCLUSION
The clinical relevance of these findings is not completely understood yet. As the sample sizes of included studies were rather small and the content of them was broad, further investigations are needed to define to which extent the described changes actually clinically meaningful, whether they are capable of influencing the female health and how these findings can be used to increase well-being
Hybrid umbilical cord blood banking: literature review.
Get PDFPURPOSE
Interest gaps between public and private umbilical cord blood banks have led to the introduction of hybrid banking options. Hybrid models combine features of private and public banks as well as interests of parents, children and of patients, in order to find an optimized solution. While several different models of hybrid banks exist, there is a lack of literature about this novel model of cord blood stem cell banking. Therefore, the aim of this literature review is to assess different options of umbilical cord blood banking and whether hybrid banking could be a valuable alternative to the existing public and private cord blood banking models.
METHODS
We performed a systematic literature search, using five main databases. Five hybrid models regarding their advantages as well as their challenges are discussed in this review.
RESULTS
We found that a wealth of literature exists about public cord blood banking, while private and hybrid banking are understudied. Different modalities of hybrid cord blood banking are being described in several publications, providing the basis to assess different advantages and disadvantages as well as practicability.
CONCLUSION
Hybrid banks, especially the sequential model, seem to have potential as an alternative to the existing banking models worldwide. A previously conducted survey among pregnant women showed a preference for hybrid banking, if such an option was available. Nevertheless, opinions among stakeholders differ and more research is needed to evaluate, if hybrid banking provides the expected benefits
Advancing laser ablation assessment in hyperspectral imaging through machine learning.
No full textHyperspectral imaging (HSI) is gaining increasing relevance in medicine, with an innovative application being the intraoperative assessment of the outcome of laser ablation treatment used for minimally invasive tumor removal. However, the high dimensionality and complexity of HSI data create a need for end-to-end image processing workflows specifically tailored to handle these data. This study addresses this challenge by proposing a multi-stage workflow for the analysis of hyperspectral data and allows investigating the performance of different components and modalities for ablation detection and segmentation. To address dimensionality reduction, we integrated principal component analysis (PCA) and t-distributed stochastic neighbor embedding (t-SNE) to capture dominant variations and reveal intricate structures, respectively. Additionally, we employed the Faster Region-based Convolutional Neural Network (Faster R-CNN) to accurately localize ablation areas. The two-stage detection process of Faster R-CNN, along with the choice of dimensionality reduction technique and data modality, significantly influenced the performance in detecting ablation areas. The evaluation of the ablation detection on an independent test set demonstrated a mean average precision of approximately 0.74, which validates the generalization ability of the models. In the segmentation component, the Mean Shift algorithm showed high quality segmentation without manual cluster definition. Our results prove that the integration of PCA, t-SNE, and Faster R-CNN enables improved interpretation of hyperspectral data, leading to the development of reliable ablation detection and segmentation systems
ALFREDO: Active Learning with FeatuRe disEntangelement and DOmain adaptation for medical image classification.
No full textState-of-the-art deep learning models often fail to generalize in the presence of distribution shifts between training (source) data and test (target) data. Domain adaptation methods are designed to address this issue using labeled samples (supervised domain adaptation) or unlabeled samples (unsupervised domain adaptation). Active learning is a method to select informative samples to obtain maximum performance from minimum annotations. Selecting informative target domain samples can improve model performance and robustness, and reduce data demands. This paper proposes a novel pipeline called ALFREDO (Active Learning with FeatuRe disEntangelement and DOmain adaptation) that performs active learning under domain shift. We propose a novel feature disentanglement approach to decompose image features into domain specific and task specific components. Domain specific components refer to those features that provide source specific information, e.g., scanners, vendors or hospitals. Task specific components are discriminative features for classification, segmentation or other tasks. Thereafter we define multiple novel cost functions that identify informative samples under domain shift. We test our proposed method for medical image classification using one histopathology dataset and two chest X-ray datasets. Experiments show our method achieves state-of-the-art results compared to other domain adaptation methods, as well as state of the art active domain adaptation methods
Profiles of success: The role of parents and coaches in the development of professional soccer players
No full textObjectives: The theoretical landscape of talent development in soccer is acknowledged as a multidisciplinary problem (Williams et al., 2020). Despite this consensus, sociological factors commonly identified in several developmental models (Bronfenbrenner, 1979; Côté et al., 2020) like parental and coaching influence remain underexplored in current research, warranting increased attention. Methodologically, existing studies predominantly employ a variable-oriented lens, linking parental or coaching behavior (e.g., pressure, support) to various talent developmental variables (e.g., success, performance; Coutinho et al., 2021; Murray et al., 2021; Sieghartsleitner et al., 2019). However, this approach neglects individual heterogeneity and fails to capture the complex interactions (and compensation) within a person (Lienhart et al., 2020; Zuber et al., 2015). An alternative, person-oriented approach is required for understanding how “types of persons”, with distinct combinations of parental and coach support, evolve uniquely over time, potentially influencing their likelihood of future success.
Methods: This longitudinal study examines the development of 108 elite youth soccer players, born in 1999 and 2000 at two measurement points in 2011 (U13) and 2012 (U14). By utilizing the person-oriented approach (Bergman et al., 2003), the study aims to create profiles (i.e., types of persons) of perceived leadership behavior (Leadership scale for sports; Chelladurai & Saleh, 1980) and perceived parental influence (Parental involvement in sport questionnaire; Lee & McLean, 1997), analyzing their impact on soccer performance levels at adulthood in 2023.
Results: In the preliminary findings, two distinct profiles emerged as potential indicators for achieving elite adult soccer performance: well-supported athletes with moderately involved parents and average-supported athletes with highly involved parents. The profiles suggest a relative stability in parental involvement, whereas coach behavior exhibits considerable variability.
Conclusion: This highlights the importance of coaches and parents in talent development and how they balance pressure and support and the possibility of compensatory mechanisms between coaches and parents
How to talk about dying? The development of an evidence-based model for communication with patients in their last days of life and their family caregivers.
Get PDFOBJECTIVE
To help healthcare professionals (HCP) act with more confidence when communicating about approaching death, we sought to develop a communication model for HCP to facilitate conversations with dying patients and family caregivers (FC) in nonemergency situations.
METHODS
We used a four-phase integrative approach: (1) creation of a preliminary model based on a systematic literature review and expert knowledge, (2) review of the model draft by international palliative care experts, (3) review by key stakeholders, and (4) final appraisal by communication experts.
RESULTS
After the clinical recognition of dying, the communication model provides a structure and practical communication aids for navigating the conversation based on three phases. It describes the content and relational level as core dimensions of effective conversations about approaching death and highlights the importance of HCP self-awareness and self-care when caring for the dying.
CONCLUSION
Based on systematic involvement of key stakeholders, the model supports clinicians navigating challenging conversations about approaching death with dying patients and their FC successfully and with more confidence.
INNOVATION
This study expands the theoretical basis for communication about approaching death and offers a pragmatic model for educational interventions and clinical use
Epitranscriptomic mechanisms of androgen signalling and prostate cancer.
Get PDFProstate cancer (PCa) is the second most common cancer diagnosed in men. While radical prostatectomy and radiotherapy are often successful in treating localised disease, post-treatment recurrence is common. As the androgen receptor (AR) and androgen hormones play an essential role in prostate carcinogenesis and progression, androgen deprivation therapy (ADT) is often used to deprive PCa cells of the pro-proliferative effect of androgens. ADTs act by either blocking androgen biosynthesis (e.g. abiraterone) or blocking AR function (e.g. bicalutamide, enzalutamide, apalutamide, darolutamide). ADT is often effective in initially suppressing PCa growth and progression, yet emergence of castrate-resistant PCa and progression to neuroendocrine-like PCa following ADT are major clinical challenges. For this reason, there is an urgent need to identify novel approaches to modulate androgen signalling to impede PCa progression whilst also preventing or delaying therapy resistance. The mechanistic convergence of androgen and epitranscriptomic signalling offers a potential novel approach to treat PCa. The epitranscriptome involves covalent modifications of mRNA, notably, in the context of this review, the N(6)-methyladenosine (m6A) modification. m6A is involved in the regulation of mRNA splicing, stability, and translation, and has recently been shown to play a role in PCa and androgen signalling. The m6A modification is dynamically regulated by the METTL3-containing methyltransferase complex, and the FTO and ALKBH5 RNA demethylases. Given the need for novel approaches to treat PCa, there is significant interest in new therapies that target m6A that modulate AR expression and androgen signalling. This review critically summarises the potential benefit of such epitranscriptomic therapies for PCa patients
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