rheology of wood flour filled poly lactic acid

Abstract This work investigates the rheological properties of wood flour filled poly(lactic acid) at typical processing temperatures, i.e. 155°C, 165°C and 175°C, using a parallel plate rheometer run in oscillatory mode. Materials with three different filler loading levels (10, 20 and 30% wt.) are characterized together with the neat matrix. Considering the complex viscosity curves, it is found that a single master curve can be obtained, which allows to predict the viscosity of the material at any filler loading level and any temperature that are included in the interval tested

Ceramic Materials as an Alternative to Titanium for Dental Implant Fabrication

Titanium is the gold standard material to produce dental implants from more than 30 years, showing high success rate in different clinical scenarios. Zirconia implants were recently introduced to overwhelm some aesthetic and biological problems that can arise from titanium. Preclinical studies show that, from a mechanical point of view, zirconia may be a suitable substitute for titanium in implant fabrication. Three-dimensional finite element analysis (FEA) models found no difference between titanium and titanium-zirconium alloy implants, neither for early nor conventional functional loading. Nevertheless, zirconia presents the same osseoconductive properties of the titanium, even if the few clinical studies show survival and success rates slightly inferior for zirconia implants comparing to titanium ones, and long-term follow-ups are missing. For these reasons, the majority of authors agree to be cautious for proposing zirconia implants as widespread substitute of titanium implants

Physical activity scale for the elderly: translation, cultural adaptation, and validation of the Italian version

Objective. The aim of the study was to translate and culturally adapt the Physical Activity Scale for the Elderly into Italian (PASE-I) and to evaluate its psychometric properties in the Italian older adults healthy population. Methods. For translation and cultural adaptation, the "Translation and Cultural Adaptation of Patient-Reported Outcomes Measures" guidelines have been followed. Participants included healthy individuals between 55 and 75 years old. The reliability and validity were assessed following the "Consensus-Based Standards for the Selection of Health Status Measurement Instruments" checklist. To evaluate internal consistency and test-retest reliability, Cronbach's α and Intraclass Correlation Coefficient (ICC) were, respectively, calculated. The Berg Balance Score (BBS) and the PASE-I were administered together, and Pearson's correlation coefficient was calculated for validity. Results. All the PASE-I items were identical or similar to the original version. The scale was administered twice within a week to 94 Italian healthy older people. The mean PASE-I score in this study was 159±77.88. Cronbach's α was 0.815 (p < 0.01) and ICC was 0.977 (p < 0.01). The correlation with the BBS was 0.817 (p < 0.01). Conclusions. The PASE-I showed positive results for reliability and validity. This scale will be of great use to clinicians and researchers in evaluating and managing physical activities in the Italian older adults population

Recent Advances in the Treatment of Neurodegenerative Diseases Based on GSH Delivery Systems

Neurodegenerative diseases, such as Parkinson's disease (PD) and Alzheimer's disease(AD), are a group of pathologies characterized by a progressive and specific loss of certain brain cell populations. Oxidative stress, mitochondrial dysfunction, and apoptosis play interrelated roles in these disorders. It is well documented that free radical oxidative damage, particularly on neuronal lipids, proteins, DNA, and RNA, is extensive in PD and AD brains. Moreover, alterations of glutathione (GSH) metabolism in brain have been implicated in oxidative stress and neurodegenerative diseases. As a consequence, the reduced GSH levels observed in these pathologies have stimulated a number of researchers to find new potential approaches for maintaining or restoring GSH levels. Unfortunately, GSH delivery to the central nervous system (CNS) is limited due to a poor stability and low bioavailability. Medicinal-chemistry- and technology-based approaches are commonly used to improve physicochemical, biopharmaceutical, and drug delivery properties of therapeutic agents. This paper will focus primarily on these approaches used in order to replenish intracellular GSH levels, which are reduced in neurodegenerative diseases. Here, we discuss the beneficial properties of these approaches and their potential implications for the future treatment of patients suffering from neurodegenerative diseases, and more specifically from PD and AD

Comparative Analysis of Sliding Resistance of Different Lingual Systems

Objective:&nbsp;To analyse and compare the frictional properties of 4 lingual systems combined with two types of stainless steel archwire (0.016x0.022, 0.018x0.025) and a 0.018x0.025 TMA archwire by simulating different misalignment situations in vitro.&nbsp;Material and Methods:&nbsp;Five randomly chosen brackets from each system (e-Brace, Harmony, Incognito, and STb) were used for the measurements and to simulate an upper first premolar extraction case. The friction tests were performed using a material testing machine in combination with a specialized test rig.&nbsp;Results:&nbsp;The lowest absolute friction values were found with the 0.016x0.022 SS wire in a passive configuration. STb provided the lowest mean friction, while Harmony brackets displayed the highest friction. The TMA Beta Titanium wire showed the highest friction values, but maintained proportions similar to those of the other wires as tip and torsion increased.&nbsp;Conclusion:&nbsp;The type of bracket has a significant impact on friction, and there is a positive correlation between mesiodistal bracket width and resistance to sliding. The archwire sections and materials and the vertical displacement, also significantly affect the friction generated by the system

Uterine artery Doppler in predicting pregnancy outcome in women with connective tissue disorders

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Vocal Tract Discomfort Scale (VTDS) and Voice Symptom Scale (VoiSS) in the Early Identification of Italian Teachers with Voice Disorders

Introduction The current Italian law does not include any guidance regarding voice education, prevention of voice disorders and screening in subjects with high vocal loading such as teachers. Objectives We aimed to check the correlation between the Vocal Tract Discomfort Scale (VTDS) with the Voice Symptom Scale (VoiSS) for the evaluation of Italian teachers. In addition, we aimed to investigate whether there are differences in the frequency and intensity of discomfort symptoms in teachers with disabilities comparing vocal tract discomfort symptoms in teachers with high risk (HRVD) and low risk (LRVD) of vocal disorders according to the VoiSS cutoff (> 15.5). Methods We analyzed 160 Italian teachers (111 women and 49 men) that completed the VTDS and VoiSS at vocal evaluation. The Spearman correlation test was applied to all variables. The Mann-Whitney U test was used to compare the average number of discomfort symptoms among HRVD and LRVD teachers. Results A moderate positive correlation was observed between the average number, frequency, and intensity of discomfort symptom and the total score, physical domain score, and limitation domain score of the VoiSS. Only the emotional domain score of the VoiSS showed a weak positive correlation ( p < 0.001). Teachers considered in the HRVD group according to the VoiSS score had a higher number, frequency, and intensity of vocal tract discomfort symptoms. Conclusion There is correlation between the VTDS and VoiSS scales. Like the VoiSS, the VTDS is a questionnaire that detects HRVD teachers. Therefore, the results suggest that both questionnaires could be useful for a preventive voice program for Italian teacher

The Social Brain and Emotional Contagion: COVID-19 Effects

Background and objectives: Coronavirus disease 2019 (COVID-19) is a highly contagious infectious disease, responsible for a global pandemic that began in January 2020. Human/COVID-19 interactions cause dierent outcomes ranging from minor health consequences to death. Since social interaction is the default mode by which individuals communicate with their surroundings, dierent modes of contagion can play a role in determining the long-term consequences for mental health and emotional well-being. We examined some basic aspects of human social interaction, emphasizing some particular features of the emotional contagion. Moreover, we analyzed the main report that described brain damage related to the COVID-19 infection. Indeed, the goal of this review is to suggest a possible explanation for the relationships among emotionally impaired people, brain damage, and COVID-19 infection. Results: COVID-19 can cause several significant neurological disorders and the pandemic has been linked to a rise in people reporting mental health problems, such as depression and anxiety. Neurocognitive symptoms associated with COVID-19 include delirium, both acute and chronic attention and memory impairment related to hippocampal and cortical damage, as well as learning deficits in both adults and children. Conclusions: Although our knowledge on the biology and long-term clinical outcomes of the COVID-19 infection is largely limited, approaching the pandemic based on lessons learnt from previous outbreaks of infectious diseases and the biology of other coronaviruses will provide a suitable pathway for developing public mental health strategies, which could be positively translated into therapeutic approaches, attempting to improve stress coping responses, thus contributing to alleviate the burden driven by the pandemic

Reverse engineering of mandible and prosthetic framework: Effect of titanium implants in conjunction with titanium milled full arch bridge prostheses on the biomechanics of the mandible.

This study aimed at investigating the effects of titanium implants and different configurations of full-arch prostheses on the biomechanics of edentulous mandibles. Reverse engineered, composite, anisotropic, edentulous mandibles made of a poly(methylmethacrylate) core and a glass fibre reinforced outer shell were rapid prototyped and instrumented with strain gauges. Brånemark implants RP platforms in conjunction with titanium Procera one-piece or two-piece bridges were used to simulate oral rehabilitations. A lateral load through the gonion regions was used to test the biomechanical effects of the rehabilitations. In addition, strains due to misfit of the one-piece titanium bridge were compared to those produced by one-piece cast gold bridges. Milled titanium bridges had a better fit than cast gold bridges. The stress distribution in mandibular bone rehabilitated with a one-piece bridge was more perturbed than that observed with a two-piece bridge. In particular the former induced a stress concentration and stress shielding in the molar and symphysis regions, while for the latter design these stresses were strongly reduced. In conclusion, prosthetic frameworks changed the biomechanics of the mandible as a result of both their design and manufacturing technology

Another one in the chamber: cabozantinib for patients with metastatic non clear cell renal cell carcinoma

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