Eco-Friendly Cork-Polyurethane Biocomposites for Enhanced Impact Performance: Experimental and Numerical Analysis.

Cork composites are byproducts from wine stopper production, resulting from the agglomeration of cork granules with a thermoset resin. The resulting compound is a versatile and durable material with numerous industrial applications. Due to its unique properties, such as low-density, high-strength, excellent energy absorption, and good thermal and acoustic insulators, cork composites find room for application in demanding industries such as automotive, construction, and aerospace. However, agglomerated cork typically has a polyurethane matrix derived from petrochemical sources. This study focuses on developing eco-friendly porous polyurethane biocomposites manufactured with the used cooking oil polyol modified with cork. Since cork and polyurethane foam are typically used for impact shock absorption, the manufactured samples were subjected to impact loading. The assessment of crashworthiness is performed through 100 J impact tests. A finite element numerical model was developed to simulate the compression of these new composites under impact, and the model validation was performed. The highest specific absorbed energy was obtained for petrochemical polyol composites with the 3% addition of natural or modified cork. The research conducted in this study showcased the feasibility of substituting certain petrochemical components used for the synthesis of the polyurethane matrix with ecological waste vegetable oil components.

Numerical and physical modeling of breast cancer based on image fusion and artificial intelligence.

PURPOSE: The key problem raised in the paper is the change in the position of the breast tumor due to magnetic resonance imaging examinations in the abdominal position relative to the supine position during the surgical procedure. Changing the position of the patient leads to significant deformation of the breast, which leads to the inability to indicate the location of the neoplastic lesion correctly. METHODS: This study outlines a methodological process for treating cancer patients. Pre-qualification assessments are conducted for magnetic resonance imaging (MRI), and 3D scans are taken in three positions: supine with arms raised, supine surgical position (SS), and standing. MRI and standard ultrasonography (USG) imaging are performed, and breast and cancer tissue are segmented from the MRI images. Finite element analysis is used to simulate tissue behavior in different positions, and an artificial neural network is trained to predict tumor dislocation. Based on the model, a 3D-printed breast with a highlighted tumor is manufactured. This computer-aided analysis is used to create a detailed surgical plan, and lumpectomy surgery is performed in the SS. In addition, the geometry of the tumor is presented to the medical staff as a 3D-printed element. RESULTS: By utilizing a comprehensive range of techniques, including pre-qualification assessment, 3D scanning, MRI and USG imaging, segmentation of breast and cancer tissue, model analysis, image fusion, finite element analysis, artificial neural network training, and additive manufacturing, a detailed surgical plan can be created for performing lumpectomy surgery in the supine surgical position. CONCLUSION: The new approach developed for the pre-operative assessment and surgical planning of breast cancer patients has demonstrated significant potential for improving the accuracy and efficacy of surgical procedures. This procedure may also help the pathomorphological justification. Moreover, transparent 3D-printed breast models can benefit breast cancer operation assistance. The physical and computational models can help surgeons visualize the breast and the tumor more accurately and detailedly, allowing them to plan the surgery with greater precision and accuracy.

Assessment of child safety on bicycles in baby carriers - The importance of evaluating both head and neck injuries.

INTRODUCTION: The paper addresses an important accident type that involves children in bicycle seats - the bicycle fall over. It is a significant and common accident type and many parents have been reported to experience this type of "close call." The fall over occurs at low velocities and even while a bicycle is standing still, and may result from a split-second lack of attention on behalf of the accompanying adult (e.g. while loading groceries, i.e. while not being exposed to traffic per se). Moreover, irrespective of the low velocities involved, the trauma that may result to the head of the child is considerable and may be life-threatening, as shown in the study. METHOD: The paper presents two methods to address this accident scenario in a quantitative way: in-situ accelerometer-based measurement and numerical modeling approaches. It is shown that the methods produce consistent results under the prerequisites of the study. They are therefore promising methods to be used in the study of this type of accident. RESULTS: The importanance of the protective role of a child helmet is without discussion in everyday traffic.However, this study draws attention to one particular effect observed in this accident type: that the geometry of the helmet may at times expose the child's head to considerably larger forces, by having contact with the ground. The study also highlights the importance of neck bending injuries during bicycle fall over, which are often neglected in the safety assessment - not only for children in bicycle seats. The study concludes that considering only head acceleration may lead to biased conclusions about using helmets as protective devices.

Cork Porous Biocomposites with Polyurethane Matrix Modified with Polyol Based on Used Cooking Oil.

Renewable materials are materials that are replenished naturally and can be used again and again. These materials include things such as bamboo, cork, hemp, and recycled plastic. The use of renewable components helps to reduce the dependence on petrochemical resources and reduce waste. Adopting these materials in various industries such as construction, packaging, and textiles can lead to a more sustainable future and decrease the carbon footprint. The presented research describes new porous polyurethane biocomposites based on used cooking oil polyol (50 per hundred polyol-php) modified with cork (3, 6, 9, and 12 php). The research described here demonstrated that it is possible to replace some petrochemical raw materials with raw materials of renewable origin. This was achieved by replacing one of the petrochemical components used for the synthesis of the polyurethane matrix with a waste vegetable oil component. The modified foams were analyzed in terms of their apparent density, coefficient of thermal conductivity, compressive strength at 10% of deformation, brittleness, short-term water absorption, thermal stability, and water vapor permeability, while their morphology was examined using scanning electron microscopy and the content of closed cells. After the successful introduction of a bio-filler, it was found that the thermal insulation properties of the modified biomaterials were comparable to those of the reference material. It was concluded that it is possible to replace some petrochemical raw materials with raw materials of renewable origin.

Improvement and validation of a female finite element model of the cervical spine.

Although the cervical spine supports and controls the kinematics of the head, it is vulnerable to injuries during mechanical loading. Severe injuries often result in damage to the spinal cord, leading to significant ramifications. The role of gender in determining the outcome of such injuries has been established as significant. In order to better understand the essential mechanics and develop treatments or preventative measures, various forms of research have been conducted. Computational modelling is one of the most useful and extensively utilised methods, as it provides information that would otherwise be difficult to obtain. As such, the primary goal of this research is to create a new finite element of the female cervical spine that will more accurately represent the group most affected by such injuries. This work is a continuation of a previous study where a model was created from the computer tomography scans of a 46-year-old female. A functioning spinal unit consisting of the C6-C7 segment was simulated as a validation procedure. The experimental data obtained from cadaveric specimens, that assessed the range of motion of different cervical segments in flexion-extension, axial rotation, and lateral bending, was used to validate the reduced model.

Development, validation and a case study: The female finite element head model (FeFEHM).

BACKGROUND AND OBJECTIVE: Traumatic brain injuries are one of the leading causes of death and disability in the world. To better understand the interactions and forces applied in different constituents of the human head, several finite element head models have been developed throughout the years, for offering a good cost-effective and ethical approach compared to experimental tests. Once validated, the female finite element head model (FeFEHM) will allow a better understanding of injury mechanisms resulting in neuronal damage, which can later evolve into neurodegenerative diseases. METHODS: This work encompasses the approached methodology starting from medical images and finite element modelling until the validation process using novel experimental data of brain displacements conducted on human cadavers. The material modelling of the brain is performed using an age-specific characterization of the brain using microindentation at dynamic rates and under large deformation, with a similar age to the patient used to model the FeFEHM. RESULTS: The numerical displacement curves are in good accordance with the experimental data, displaying similar peak times and values, in all three anatomical planes. The case study result shows a similarity between the pressure fields of the FeFEHM compared to another model, highlighting the future potential of the model. CONCLUSIONS: The initial objective was met, and a new female finite element head model has been developed with biofidelic brain motion. This model will be used for the assessment of repetitive impact scenarios and its repercussions on the female brain.

Analysis of electric scooter user kinematics after a crash against SUV.

The article presents the results of the analysis of electric scooter user kinematics after a crash against a vehicle. The share of electric scooters (e-scooters) in urban traffic has been growing in recent years. The number of road accidents involving e-scooters is also increasing. However, the safety situation of electric scooter users is insufficiently researched in terms of kinematics and injury outcomes. The article presents the importance of this problem based on an in-depth literature analysis of e-scooter-related types of accidents, injuries percentages, and helmet use. Subsequently, four accident scenarios were designed and simulated using two numerical codes-LS-DYNA for handling finite element (FE) code (the vehicle and scooter model) and MADYMO for multibody code (dummy model). Scenario one is a side bonnet crash that simulates an accident when the scooter drives into the side-front of the vehicle. The second and the third simulation is a side B-pillar crash, which was divided into two dummy's positions: the squat and up-right. The fourth simulation is a frontal impact. For each scenario, subsequent frames describing the dummy movement are presented. The after-impact kinematics for various scenarios were analyzed and discussed. The plots of the dummy's head linear acceleration and its magnitude for the analyzed scenarios were provided. As the study is devoted to increasing riders safety in this means of transportation, the potential directions for further research were indicated.

Analysis of HIC and Hydrostatic Pressure in the Human Head during NOCSAE Tests of American Football Helmets.

Brain damage is a serious economic and social burden. Contact sports such as American football, are one of the most common sources of concussions. The biomechanical response of the head-helmet system caused by dynamic loading plays a major role. The literature has focused on measuring the resultant kinematics that act on the head and helmet during tackles. However, few studies have focused on helmet validation tests, supported by recent findings and emerging numerical approaches. The future of helmet standards could benefit from insights at the level of injury mechanisms, using numerical tools to assess the helmets. Therefore, in this work, a numerical approach is employed to investigate the influence of intracranial pressure (ICP) on brain pathophysiology during and after helmeted impacts, which are common in American football. The helmeted impacts were performed at several impact locations according to the NOCSAE standard (configurations A, AP, B, C, D, F, R, UT). In order to evaluate the ICP levels, the αHEAD finite element head and brain model was combined with a Hybrid III-neck structure and then coupled with an American football helmet to simulate the NOCSAE impacts. In addition, the ICP level was analyzed together with the resulting HIC value, since the latter is commonly used, in this application and others, as the injury criterion. The obtained results indicate that ICP values exceed the common threshold of head injury criteria and do not correlate with HIC values. Thus, this work raises concern about applying the HIC to predict brain injury in American football direct head impacts, since it does not correlate with ICP predicted with the FE head model.

Transformation of a glandular odontogenic cyst into mucoepidermoid carcinoma of the mandible: A case report.

The glandular odontogenic cyst (GOC) is a rare pathology of odontogenic origin, which can behave unpredictably. It is problematic in clinical, radiographic and histological diagnostics. Intraosseous mucoepidermoid carcinoma (MEC) is a rare tumor which affects the jaws, typically found in the mandible. This malignancy, which usually originates from the salivary glands, can also be caused by a transformation of the mucous cells found in odontogenic cysts. This article presents a rare case of GOC transforming into MEC of the mandible, which was reported during the treatment of a 52-year-old male patient. The aim of this work was to present some of the therapeutic and clinical difficulties encountered when GOC transforms into mucoepidermoid cancer in the mandible, considering the pathomorphological and histological differentiations. The differentiation between MEC and GOC might be difficult through microscopic examination and requires the cooperation of a clinician ­ a maxillofacial surgeon ­ and a histopathologist.

Calcifying Epithelial Odontogenic Tumour. Review of the literature and own experience.

The present paper discusses the case of a patient who was surgically treated for a rare calcifying epithelial odontogenic tumour (Pindborg tumour) at the Department of Maxillofacial Surgery, F. Chopin Clinical Voivodeship Hospital in Rzeszow. Calcifying Epithelial Odontogenic Tumour (CEOT) is a benign odontogenic tumour arising from the remnants of the dental lamina epithelium. The first three cases of this tumour were recognized by the Danish pathologist J.J. Pindborg in 1955. Since then Calcifying Epithelial Odontogenic Tumour has been commonly referred to as the Pindborg tumour. This type of neoplasm is relatively rare, since it occurs in approximately 0.4% of all odontogenic tumour cases. Due to a fairly common tendency of recurrence, estimated to be approximately 14% of all cases, the preferred o choice of treatment is radical surgical procedure and postoperative follow-up. Appropriate clinical and histopathological diagnosis is very important before applying the most suitable surgical treatment. Based on the case reviewed and the available literature, we can confirm the suitability of the therapeutic procedure course aligned with contemporary views, guidelines and established standards.

Observations on surgical reconstructive management following the excision of malignant neoplasms of the eyelid and periocular area.

BACKGROUND: The surgical treatment of malignant neoplasms of the eyelid and the periocular area, due to the complex structure of the eye protective apparatus, remains a difficult surgical problem. The aim is to reconstruct the missing tissue as precisely as possible, both from a functional and esthetic point of view. Postoperative disorders of eyelid function may considerably disturb both the functioning and the quality of life of the patients. OBJECTIVES: The aim of the study was to evaluate 262 patients who had underwent operations related to malignant neoplasms of the eyelid and the periocular area, and to demonstrate which reconstruction methods for post-resection defects were the most advantageous in terms of functions and esthetics. MATERIAL AND METHODS: The study was based on an analysis of the medical records of 262 patients. The analysis included the reconstruction techniques used, the patient's age, the sizes and locations of the primary skin cancer, any healing complications, and the distant esthetic and functional outcomes. RESULTS: Various types of flap procedures were the most frequently used techniques in the studied group of patients (66.8%). Single flaps were used in 83 patients, multiple flaps in 89 patients and complex flaps with a cartilage graft in 3 patients. Free skin grafts were used in 52 patients and were associated with complications in the form of partial necrosis. Complications during postoperative wound healing were observed in 18.3% of the patients. In 12 patients, the complications were associated with a local infection, in 15 patients with partial, marginal necrosis and in 8 patients partial wound breakdown after the transfer of the flap occurred. CONCLUSIONS: The most frequently used mechanisms for correction and reconstruction of the deficits following the excision of the eyelid skin and periorbital malignancies included various flaps used in a total of 175 patients (66.8%).

Clinical-pathological characteristics of patients treated for cancers of the eyelid skin and periocular areas.

BACKGROUND: Malignant cancers of the eyelid skin and the periocular area comprise 5-10% of facial skin malignant cancers. Basal cell carcinomas (BCCs) dominate, comprising approx. 80-90% of cancers of this area of the face. Considerably less often, in 9-14% of cases, squamous cell carcinomas (SCCs) are observed. OBJECTIVES: The aim of this study is to provide an epidemiological-clinical assessment of patients treated over the period 2006-2015 for primary malignant cancers of the eyelid skin considering histological diagnosis and clinical staging. MATERIAL AND METHODS: This study was based on an analysis of the medical records of 262 patients. Demographic data, age, sex, size and location of lesions, histological types, and clinical staging were assessed. RESULTS: In the analyzed group of 262 patients, most were over the age of 60 years. Primary cancers were most frequently located in the area of the medial canthus of the eye and in the lower eyelid skin. They were mainly lesions of 6-10 mm and 16-20 mm with histologically diagnosed basal cell carcinoma of nodular and cystic types. CONCLUSIONS: The most represented group was that of patients aged 60-70 years with primary cancers located in the medial canthus of the eye (47.3%) and in the lower eyelid. Basal cell carcinoma was diagnosed, mainly nodular and cystic types.