Search

Finite element analysis (FEA) is a fundamental tool that can be used in the orthopaedic world to simulate and analyze the behaviour of different surgical procedures. It is important to be aware that removing more than 20% of the meniscus could increase the shear stress in the cartilage and enlarge the risk of knee joint degeneration. In this fact, the maximal shear stress value in the medial cartilage increased up to 225% from 0.15 MPa to 0.5 MPa after medial meniscectomy. Also, meniscal root repair can improve meniscal biomechanics and potentially reduce the risk of osteoarthritis, even in cases of a loose repair. FEA has been used to better understand the biomechanical role of cruciate ligaments in the knee joint. ACLr with bone-patellar tendon-bone graft at 60 N of pretension and double-bundle PCLr were closer to that of a native knee in terms of biomechanics. The addition of a lateral extra-articular augmentation technique can reduce 50% of tibial translation and internal rotation, protecting the graft and minimizing the risk of re-rupture. Interestingly, anatomic and non-anatomic medial patellofemoral ligament reconstruction increased the pressure applied to the patellofemoral joint by increasing patellar contact pressure to 0.14 MPa at 30° of knee flexion using the semitendinosus as a graft. After all the advances in medical imaging technologies, future studies should take into consideration patient-specific data on both anatomy and mechanics, in order to better personalize the experimental model.

Many studies have assessed students' motivation through surveys, but only a few studies systematically investigated through students' own words the reasons and aims of their achievement striving. In the present study, we rely on the Goal Complex Perspective (Sommet and Elliot in J Educ Psychol 109(8):1141--1162, 2017. https://doi.org/10.1037/edu0000199; Vansteenkiste et al. in Educ Psychol 49(3):153-174, 2014. https://doi.org/10.1080/00461520.2014.928598) to uncover qualitative differences in achievement motivation. Content analysis of 1303 statements made by 597 Greek secondary students revealed (i) more autonomous motivation than controlled motivation statements, (ii) spontaneously generated statements of mastery-learning and outcome goals but rarely of performance-normative goals, (iii) mastery-learning goals being coupled with both autonomous and controlled motivation, providing ecological support for the conceptualization of mastery goal complexes. Logistic regression analyses verified our classification, as students' statements were predicted by corresponding types of motivation assessed by close, Likert-type questions. These findings, which align with the Goal Complex Perspective, are discussed in terms of the operational definition of autonomous and controlled motivation and achievement goals.

Congenital agenesis of major salivary glands is considered a very infrequent condition and typically appears to be a coincidental finding. It can be present as sporadic case or may be combined with aplasia or hypoplasia of other salivary glands or the lacrimal glands, or as a part of syndromes. Only 23 cases documented in the literature to date, while the youngest patient was 50 days old. Plenty of radiographic useful techniques and treatment is closely related to the clinical manifestations; therefore. We present a case of 52 year old female who was referred to our radiology department for recurrent numbness of the left upper limb, experienced over the previous three months. Complete absence of the left parotid gland was incidentally demonstrated at the brain MRI scan. Based on the patient’s past medical history, physical examination and demonstrated radiographic techniques it was an asymptomatic, no-syndromic and no-familious unilateral aplasia of the parotid gland. In the present report, we aimed to underline that this rare condition may be asymptomatic and co-exist with other medical conditions and syndromes.

Introduction: This study aims to assess the utility of Boosting ensemble classification methods for increasing the diagnostic performance of multiparametric Magnetic Resonance Imaging (mpMRI) radiomic models, in differentiating benign and malignant breast lesions. Methods: The dataset includes mpMR images of 140 female patients with mass-like breast lesions (70 benign and 70 malignant), consisting of Dynamic Contrast Enhanced (DCE) and T2-weighted sequences, and the Apparent Diffusion Coefficient (ADC) calculated from the Diffusion Weighted Imaging (DWI) sequence. Tumor masks were manually defined in all consecutive slices of the respective MRI volumes and 3D radiomic features were extracted with the Pyradiomics package. Feature dimensionality reduction was based on statistical tests and the Boruta wrapper. Hierarchical Clustering on Spearman's rank correlation coefficients between features and Random Forest classification for obtaining feature importance, were implemented for selecting the final feature subset. Adaptive Boosting (AdaBoost), Gradient Boosting (GB), Extreme Gradient Boosting (XGBoost) and Light Gradient Boosting Machine (LightGBM) classifiers, were trained and tested with bootstrap validation in differentiating breast lesions. A Support Vector Machine (SVM) classifier was also exploited for comparison. The Receiver Operator Characteristic (ROC) curves and DeLong's test were utilized to evaluate the classification performances. Results: The final feature subset consisted of 5 features derived from the lesion shape and the first order histogram of DCE and ADC images volumes. XGboost and LGBM achieved statistically significantly higher average classification performances [AUC = 0.95 and 0.94 respectively], followed by Adaboost [AUC = 0.90], GB [AUC = 0.89] and SVM [AUC = 0.88]. Conclusion: Overall, the integration of Ensemble Learning methods within mpMRI radiomic analysis can improve the performance of computer-assisted diagnosis of breast cancer lesions.

Performance at school is affected not only by students' achievement goals but also by emotional exchanges among classmates and their teacher. In this study, we investigated relationships between students' achievement goals and emotion perception ability and class affect and performance. Participants were 949 Greek adolescent students in 49 classes and their Greek language and mathematics teachers. Results from multilevel analyses indicated that students' mastery-approach and performance-approach goals were positively related to positive affect whereas performance-avoidance goals were negatively related to positive affect. At class-level, relationships between achievement goals and affect were moderated by students' emotion perception ability. These findings highlight the importance of emotion abilities and their role in motivational processes for class-level outcomes.

Study DesignHuman herniated discs were obtained from discectomy specimens for the immunohistochemical detection of O-GlcNAc and O-GlcNAcase (OGA)/O-GlcNAc transferase (OGT).PurposeThis study aimed to quantify the extent of O-GlcNAcylation and its associated enzymes (OGT/OGA) in human degenerated intervertebral discs.Overview of LiteratureThe O-GlcNAcylation of nuclear, cytoplasmic, and mitochondrial proteins as well as the effects of such post-translational modifications are currently the focus of extensive research. O-GlcNAcylation is believed to contribute to the etiology of chronic illnesses by acting as a nutrient and stress sensor in the cellular environment. Mature intervertebral disc cells are chondrocyte-like cells, and O-GlcNAc has been shown to promote chondrocyte apoptosis in vitro. We believe that O-GlcNAcylation is a key regulator of disc degeneration.MethodsFifty-six specimens were fixed for 24 hours in a 10% solution of neutral-buffered formaldehyde, dehydrated, and embedded in paraffin. Tissue slices (4-µm-thick) were used for hematoxylin-eosin staining and immunohistochemistry.ResultsWe found that O-GlcNAcylation of cytoplasmic proteins was less than that of nuclear proteins in both single cells and cell clusters. Cytoplasmic O-GlcNAcylation occurs subsequent to nuclear O-GlcNAcylation and is directly proportional to disc degeneration. OGT and O-GlcNAc expression levels were identical in all specimens examined.ConclusionsO-GlcNAc and OGA/OGT expression is shown to correlate for the first time with intervertebral disc cell degeneration. Increasing disc degeneration is associated with increasing O-GlcNAcylation in both nuclear and cytoplasmic proteins in human disc cells.

Purpose: To investigate the diagnostic efficacy of fusion guided multiparametric MRI (mpMRI)—transrectal ultrasound (TRUS) biopsy versus systematic biopsy of the prostate in patients with suspicion of prostate cancer. Methods: A total of 185 patients with PI‐RADS 3 lesions or higher underwent fusion guided targeted and systematic prostate biopsy. Histology of samples was correlated with PI‐RADS score and biopsy method for each patient. Results: A total of 81/185 (43.8%) cases positive for cancer were detected; 23/81 (28.4%) cases with clinically insignificant prostate cancer—insPCa and 58/81 (71.6%) cases with clinically significant prostate cancer—csPCa. There was a statistically significant difference in the overall detection of adenocarcinomas between methods (p =.035, McNemar test). Moreover, there was a statistically significant difference in the detection of insPCa between the two methods (p =.004, McNemar test). Systematic biopsy detected 13 patients with insPCa more (14.4%) than the targeted biopsy method. However, there is no statistical difference in the detection rate of csPCa between the two methods (p = 1, McNemar test). When both techniques were combined more cases of csPCa were detected. Conclusion: The combined implementation of fusion‐guided targeted mpMRI–TRUS and systematic biopsy of the prostate provides higher detection number of csPCa, compared to each method alone. The potential of fusion‐guided mpMRI‐TRUS biopsy of the prostate needs to be further assessed since each method has its limitations; therefore, systematic prostate biopsy still plays an important role in clinical practice. [ABSTRACT FROM AUTHOR]

The purpose of this study is to identify the prevalence of osteoporosis in male patients with chronic obstructive pulmonary disease (COPD) by dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) and to compare the diagnostic abilities of the above methods. Thirty-seven male patients with established COPD were examined with DXA and standard QCT in lumbar spine, including L1, L2, and L3 vertebrae. T-scores and bone mineral density values were calculated by DXA and QCT method, respectively. Comparative assessment of the findings was performed and statistical analysis was applied. QCT measurements found more COPD patients with impaired bone mineral density compared to DXA, namely, 13 (35.1%) versus 12 (32.4%) patients with osteopenia and 16 (43.2%) versus 9 (16.2%) patients with osteoporosis (p=0.04). More vertebrae were found with osteoporosis by QCT compared to DXA (p=0.03). The prevalence of osteoporosis among male patients with COPD is increased and DXA may underestimate this risk. QCT measurements have an improved discriminating ability to identify low BMD compared to DXA measurements because QCT is able to overcome diagnostic pitfalls including aortic calcifications and degenerative spinal osteophytes.

Objective. To assess body composition in adult male and female patients with thalassemia major by dual-energy X-ray absorptiometry (DXA) and to compare the findings with a group of healthy age-matched controls. Methods. Our study group included sixty-two patients (27 males, mean age 36 years, and 35 females, mean age 36.4 years) and fifteen age-matched healthy controls. All patients had an established diagnosis of thalassemia major and followed a regular blood transfusion scheme since childhood and chelation treatment. Fat, lean, and bone mineral density (BMD) were assessed with dual-energy X-ray absorptiometry. Ferritin levels and body mass index of all patients and controls were also recorded. Student t-test and Wilcoxon test were performed and statistical significance was set at p