Multi-Step Relaxation Characterization and Viscoelastic Modeling to Predict the Long-Term Behavior of Bitumen-Free Road Pavements Based on Polymeric Resin and Thixotropic Filler.

Asphalt pavements are fundamental to modern transportation infrastructure, requiring elasticity, firmness, and longevity. However, traditional asphalt, based on bitumen, faces several limitations. To improve pavement performance, polymer resins are being used to substitute bitumen and improve requirements. Therefore, a deep understanding of the material behavior is required. This study presents the analysis of the relaxation behavior of a poly(methyl methacrylate)-based pavement and the influence of mineral fillers. An approach using a linear elastic-viscoelastic material model was selected based on evidence and validated across the linear and nonlinear deformation range. The results reveal no influence of the mineral fillers on the relaxation behavior. The presented modification of the linear elastic and viscoelastic modeling reveals accurate results to predict long-term pavement performance. This approach offers a practical method for forecasting asphalt behavior. Further research is needed to incorporate deformation behavior into the model.

Evolution of Public Responses to COVID-19: Comparing Changes in People's Emotions, Behaviors, and Precautions at the Onset and End Stage of the Pandemic.

Introduction The coronavirus disease 2019 (COVID-19) pandemic has had a significant impact on global public health, with profound changes in people's psychological and behavioral responses to the virus. Our aim is to evaluate the evolution of people's responses to COVID-19. Methods This observational study compares two groups of YouTube videos (495 videos in the first group and 620 videos in the second group) posted during different periods of the pandemic to examine the evolution of people's emotions, behaviors, and precautions toward COVID-19. We analyzed the titles of these videos to gain insights into the evolving public responses to the pandemic and how they may impact future public health interventions. Results Our results show a shift in focus from basic prevention measures to a more nuanced approach to prevention and management, characterized by a greater emphasis on vaccination and travel-related precautions in the second group of videos. These findings can inform public health policies and interventions aimed at mitigating the impact of COVID-19 and other pandemics. Furthermore, this study highlights the potential of social media platforms, such as YouTube, as a tool for monitoring and understanding public responses to pandemics and other health crises. Conclusion Continued analysis of public responses and behaviors can help inform effective public health interventions and policies as the COVID-19 pandemic continues to evolve.

Tularemia in the Differential Diagnosis of Lymphadenitis: A Retrospective Analysis of 16 Cases.

INTRODUCTION: Tularemia is a zoonotic disease caused by Francisella tularensis, a gram-negative, facultative, intracellular coccobacillus. It can occur in different clinical forms, and the most common form in our country (Turkey) is the oropharyngeal form. Unfortunately, the diagnosis of lymphadenitis caused by tularemia is delayed unless it is suspected, especially in sporadic cases. Our aim is to remind clinicians to have tularemia among differentials of lymphadenitis. METHODS: In this study, the clinical and laboratory findings of 16 tularemia patients between 2011 and 2021 were evaluated retrospectively. RESULTS: The mean age of the 16 patients included in the study was 39 years, and 62.5% were female. The patients were diagnosed with tularemia on the average 31st day of their complaints. The rate of use of beta-lactam group antibiotics before diagnosis was 74%. About 81.25% of the patients were engaged in animal husbandry/farming, and living in rural areas (93.75%) and farming (81.25%) were the most common possible risk factors. The patients were admitted to the hospital with the most common complaints of enlarged lymph nodes (100%), fatigue (62.5%) and loss of appetite (56.25%). All patients had lymphadenopathy, and the most common location of lymphadenopathy was the cervical region (81.25%). Moxifloxacin (56.25%) was used most frequently in the treatment of tularemia, and surgical drainage was performed for 31% of the patients. CONCLUSION: The diagnosis of tularemia is often delayed unless clinical suspicion is high. Delayed diagnosis may lead to unnecessary frequent use of antibiotics, especially beta-lactam group antibiotics. As the diagnosis is delayed, since lymph node suppuration is common, surgical intervention may be required. This situation can cause extra burden for both patients and the health system. It may be beneficial to organize trainings to increase awareness among physicians and society in order to make the diagnosis early.

BRCA 1/BRCA 2 Pathogenic/Likely Pathogenic Variant Patients with Breast, Ovarian, and Other Cancers.

The demographic and clinical characteristics of patients who have BRCA 1/BRCA 2 pathogenic/likely pathogenic variants may differ from their relatives who had BRCA-related cancer. In this study, we aimed to demonstrate the clinical and demographic findings of patients who had BRCA-related cancer and to assess the differences comparing their relatives who had BRCA-related cancer with breast, genital tract, prostate, and pancreas cancers as well. The results of sequencing analysis of 200 cancer patients (190 women, 10 men) who have been directed to genetic counseling with an indication of BRCA1/BRCA2 testing from different regions across 9 medical oncology centers were retrospectively analyzed. A total of 200 consecutive cancer patients who harbored the BRCA1/BRCA2 pathogenic/likely pathogenic variant (130 (65%) patients harbored BRCA 1 pathogenic/likely pathogenic variant, and 70 harbored BRCA 2 pathogenic/likely pathogenic variant) were included. Of these, 64.0% had breast cancer (43.8% of them had the triple-negative disease, and about 2.3% had only the HER-2 mutant), 31.5% had genital cancers (92.1% of them had ovarian cancer, 3.2% had endometrium, and 1.6% had peritoneum cancer as the primary site and mostly serous adenocarcinoma was the most common histopathology and 14.3% of the patients had endometrioid adenocarcinoma), 3.5% had prostate (median time from metastasis to castration-resistant status was 28 months) and 1.0% had pancreas cancer. Newly diagnosed cancer (breast and ovary) patients who had BRCA 1/BRCA 2 pathogenic/ likely pathogenic variant were younger than their previous cancer diagnosed (breast, ovary, and pancreas) parents who harbored BRCA pathogenic/likely pathogenic variant. We suggest that the genetic screening of BRCA 1/ BRCA 2 pathogenic/likely pathogenic variant is needed as a routine screening for those with a personal or family history of breast, ovarian, tubal, or peritoneal cancer. In addition, once BRCA 1 or BRCA 2 germline pathogenic variant has been identified in a family, testing of at-risk next-generation relatives earlier can identify those family members who also have the familial pathogenic variant, and thus need increased surveillance.

Hyperelastic Material Parameter Determination and Numerical Study of TPU and PDMS Dampers.

Dampers provide safety by controlling unwanted motion that is caused due to the conversion of mechanical work into another form of energy (e.g., heat). State-of-the-art materials are elastomers and include thermoplastic elastomers. For the polymer-appropriate replacement of multi-component shock absorbers comprising mounts, rods, hydraulic fluids, pneumatic devices, or electro-magnetic devices, among others, in-depth insights into the mechanical characteristics of damper materials are required. The ultimate objective is to reduce complexity by utilizing inherent material damping rather than structural (multi-component) damping properties. The objective of this work was to compare the damping behavior of different elastomeric materials including thermoplastic poly(urethane) (TPU) and silicone rubber blends (mixtures of different poly(dimethylsiloxane) (PDMS)). Therefore, the materials were hyper- and viscoelastic characterized, a finite element calculation of a ball drop test was performed, and for validation, the rebound resilience was measured experimentally. The results revealed that the material parameter determination methodology is reliable, and the data that were applied for simulation led to realistic predictions. Interestingly, the rebound resilience of the mixture of soft and hard PDMS (50:50) wt% was the highest, and the lowest values were measured for TPU.

Mechanical Consequences of Dynamically Loaded NiTi Wires under Typical Actuator Conditions in Rehabilitation and Neuroscience.

In the field of rehabilitation and neuroscience, shape memory alloys play a crucial role as lightweight actuators. Devices are exploiting the shape memory effect by transforming heat into mechanical work. In rehabilitation applications, dynamic loading of the respective device occurs, which in turn influences the mechanical consequences of the phase transforming alloy. Hence in this work, dynamic thermomechanical material behavior of temperature-triggered phase transforming NiTi shape memory alloy (SMA) wires with different chemical compositions and geometries was experimentally investigated. Storage modulus and mechanical loss factor of NiTi alloys at different temperatures and loading frequencies were analyzed under force-controlled conditions. Counterintuitive storage modulus- and loss factor-dependent trends regarding the loading frequency dependency of the mechanical properties on the materials' composition and geometry were, hence, obtained. It was revealed that loss factors showed a pronounced loading frequency dependency, whereas the storage modulus was not affected. It was shown that force-controlled conditions led to a lower storage modulus than expected. Furthermore, it turned out that a simple empirical relation could capture the characteristic temperature dependency of the storage modulus, which is an important input relation for modeling the rehabilitation device behavior under different dynamic and temperature loading conditions, taking directly into account the material behavior of the shape memory alloy.

Embedded NiTi Wires for Improved Dynamic Thermomechanical Performance of Silicone Elastomers.

The extraordinary properties of shape memory NiTi alloy are combined with the inherent viscoelastic behavior of a silicon elastomer. NiTi wires are incorporated in a silicon elastomer matrix. Benefits include features as electrical/thermal conductivity, reinforcement along with enhanced damping performance and flexibility. To gain more insight of this composite, a comprehensive dynamic thermomechanical analysis is performed and the temperature- as well as frequency-dependent storage modulus and the mechanical loss factor are obtained. The analyses are realized for the composite and single components. Moreover, the models to express the examined properties and their temperature along with the frequency dependencies are also presented.

Adherence Kinetics of a PDMS Gripper with Inherent Surface Tackiness.

Damage and fiber misalignment of woven fabrics during discontinuous polymer processing remain challenging. To overcome these obstacles, a promising switchable elastomeric adherence gripper is introduced here. The inherent surface tackiness is utilized for picking and placing large sheets. Due to the elastomer's viscoelastic material behavior, the surface properties depend on loading speed and temperature. Different peeling speeds result in different adherence strength of an interface between the gripper and the substrate. This feature was studied in a carefully designed experimental test set-up including dynamic thermomechanical, as well as dynamic mechanical compression analyses, and adherence tests. Special emphases were given to the analyses of the applicability as well as the limitation of the viscoelastic gripper and the empirically modeling of the gripper's pulling speed-dependent adherence characteristic. Two formulations of poly(dimethylsiloxane) (PDMS) with different hardnesses were prepared and analyzed in terms of their applicability as gripper. The main insights of the analyses are that the frequency dependency of the loss factor tanδ is of particular importance for the application along with the inherent surface tackiness and the low sensitivity of the storage modulus to pulling speed variations. The PDMS-soft material formulation exhibits the ideal material behavior for an adhesive gripper. Its tanδ varies within the application relevant loading speeds between 0.1 and 0.55; while the PDMS-hard formulation reveals a narrower tanδ range between 0.09 and 0.19. Furthermore, an empirical model of the pulling speed-dependent strain energy release rate G(v) was derived based on the experimental data of the viscoelastic characterizations and the probe tack tests. The proposed model can be utilized to predict the maximum mass (weight-force) of an object that can be lifted by the gripper.

Evaluation of Retinal Nerve Fiber Layer and Ganglion Cell Complex Thickness in Unilateral Exfoliation Syndrome Using Optical Coherence Tomography.

PURPOSE: To evaluate retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness by using optical coherence tomography in unilateral exfoliation syndrome (XFS) and to assess whether exfoliation itself is an independent risk factor for glaucomatous optic nerve damage. MATERIALS AND METHODS: Thirty exfoliative eyes of unilateral XFS cases, 30 fellow eyes of unilateral exfoliation, and 30 eyes of healthy subjects were enrolled the study. Peripapillary RNFL and macular GCC thickness measurements by Cirrus HD OCT (Carl Zeiss Meditec, Dublin, CA) were performed on all subjects. RESULTS: RNFL thickness in superior quadrant was significantly different between groups (P=0.025) and it was thinner in XFS than healthy subjects (P=0.020). All GCC parameters except GCC thickness in inferior quadrant were significantly different between groups (P=0.110 for inferior quadrant, P<0.046 for other GCC parameters). GCC were thinner in XFS than healthy subjects except inferior and inferonasal quadrants (P=0.091, 0.051 for inferior and inferonasal quadrants, respectively, P<0.039 for other GCC parameters). Minimum GCC thickness, GCC thicknesses in superior, and inferonasal quadrants were significantly thinner in fellow eyes than healthy subjects (P=0.011, 0.013, 0.047, respectively). CONCLUSIONS: XFS is related with thinner RNFL and GCC even in normal intraocular pressure values, similar optic disc parameters and visual field results. XFS may be an independent risk factor for glaucomatous optic nerve damage. So, further studies are needed to evaluate whether exfoliation itself is an independent risk factor for optic nerve damage.