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1.
Cureus ; 16(1): e52267, 2024 Jan.
Article En | MEDLINE | ID: mdl-38222988

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease with limited therapeutic options. Adalimumab, an anti-tumor necrosis factor-alpha (TNF-α) monoclonal antibody, was the first biological agent approved for the treatment of moderate to severe HS. Tuberculosis (TB) is a highly prevalent global public health problem, affecting individuals worldwide. Continuous immunosuppression from TNF-α treatment increases the risk of TB development. Isolated neurotuberculosis, in the absence of other symptoms, emerges as a rarely observed infection pattern in such patients. We present a case of a 23-year-old woman with severe HS undergoing treatment with adalimumab. After two years, she developed a pronounced occipital tension headache, constant nausea, and persistent fever. The patient's latent TB status was unknown without annual screening. Subsequent magnetic resonance imaging revealed a lesion in the cerebellar vermis. Immunosuppressive therapy was suspended and an etiological study was conducted; the only positive result was the interferon-gamma release assay. Empirically, antituberculosis treatment and prednisolone were initiated, leading to clinical and neurological improvement. After one year of treatment, symptoms resolved without neurological sequelae. This case highlights the importance of vigilant monitoring before, during, and after immunosuppressive treatment. Early recognition, discontinuation of anti-tumor necrosis factor medications, and appropriate management of TB are crucial to prevent complications.

2.
Microbiol Spectr ; 12(2): e0215323, 2024 Feb 06.
Article En | MEDLINE | ID: mdl-38230933

Laboratory automation in microbiology improves productivity and reduces sample turnaround times (TATs). However, its full potential can be unlocked through the optimization of workflows by adopting lean principles. This study aimed to explore the relative impact of laboratory automation and continuous improvement events (CIEs) on productivity and TATs. Laboratory automation took place in November 2020 and consisted of the introduction of WASPLab and VITEK MS systems. CIEs were run in May and September 2021. Before the conversion, the laboratory processed about ~492 samples on weekdays and had 10 full-time equivalent (FTE) staff for a productivity of 49 samples/FTE/day. In March 2021, after laboratory automation, the caseload went up to ~621 while the FTEs decreased to 8.5, accounting for productivity improvement to 73 samples/FTE/day. The hypothetical productivity went up to 110 samples/FTE/day following CIEs, meaning that the laboratory could at that point deal with a caseload increase to ~935 with unchanged FTEs. Laboratory conversion also led to an improvement in TATs for all sample types. For vaginal swabs and urine samples, median TATs decreased from 70.3 h [interquartile range (IQR): 63.5-93.1] and 73.7 h (IQR: 35.6-50.7) to 48.2 h (IQR: 44.8-67.7) and 40.0 h (IQR: 35.6-50.7), respectively. Automation alone was responsible for 37.2% and 75.8% of TAT reduction, respectively, while the remaining reduction of 62.8% and 24.2%, respectively, was achieved due to CIEs. The laboratory reached productivity and TAT goals predefined by the management after CIEs. In conclusion, automation substantially improved productivity and TATs, while the subsequent implementation of lean management further unlocked the potential of laboratory automation.IMPORTANCEIn this study, we combined total laboratory automation with lean management to show that appropriate laboratory work organization enhanced the benefit of the automation and substantially contributed to productivity improvements. Globally, the rapid availability of accurate results in the setting of a clinical microbiology laboratory is part of patient-centered approaches to treat infections and helps the implementation of antibiotic stewardship programs backed by the World Health Organization. Locally, from the point of view of laboratory management, it is important to find ways of maximizing the benefits of the use of technology, as total laboratory automation is an expensive investment.


Automation, Laboratory , Laboratories , Female , Humans , Automation, Laboratory/methods , Time Factors
3.
Acta Med Port ; 37(2): 142-144, 2024 Feb 01.
Article En | MEDLINE | ID: mdl-37405907

Streptococcus pyogenes causes a wide spectrum of diseases in children. However, meningitis due to this pathogen is highly uncommon. Although rare, it is associated with a high case fatality rate and can result in severe neurological sequelae. We report a case of Streptococcus pyogenes meningitis in a previously healthy 3-year-old boy. The purpose of this case report is to emphasize that this agent should be considered a cause of meningitis in previously healthy infants because of its frequent association with complications, sequelae, and high mortality rates.


Meningitis, Bacterial , Streptococcal Infections , Male , Infant , Humans , Child , Child, Preschool , Streptococcus pyogenes , Meningitis, Bacterial/diagnosis , Streptococcal Infections/diagnosis , Disease Progression , Health Status
4.
Psychopathology ; 57(1): 76-80, 2024.
Article En | MEDLINE | ID: mdl-37276842

Negative symptoms reflect a currently much-untreated loss of normal functioning and are frequently found in psychotic disorders. We present the first translation of the Brief Negative Symptom Scale (BNSS) to European Portuguese and evaluate its validity in a sample of Portuguese male patients with a psychotic spectrum disorder. The Portuguese BNSS showed excellent internal consistency, high convergent validity (i.e., strong correlation with the PANSS negative factor), and high discriminant validity (i.e., a lack of association with the PANSS positive factor). In sum, the present European Portuguese BNSS has shown to be reliable, thus extending this instrument's clinical availability worldwide.


Schizophrenia , Humans , Male , Schizophrenia/diagnosis , Psychiatric Status Rating Scales , Portugal , Psychometrics , Reproducibility of Results
5.
BMJ Case Rep ; 16(11)2023 Nov 30.
Article En | MEDLINE | ID: mdl-38035679

Skene's gland duct cysts are benign, asymptomatic bulging interlabial masses that are rarely identified in female newborns. The aetiology is unknown, but it is commonly associated with in utero maternal oestrogen exposure or obstruction or stenosis of the gland duct. We report three unrelated cases of neonatal Skene's gland duct cysts that resolved spontaneously without the need for surgical intervention.


Cysts , Skin Neoplasms , Urethral Diseases , Humans , Infant, Newborn , Female , Urethral Diseases/surgery , Cysts/diagnostic imaging , Cysts/surgery
6.
J Stroke Cerebrovasc Dis ; 32(12): 107390, 2023 Dec.
Article En | MEDLINE | ID: mdl-37866295

(Objectives) Aneurysmal subarachnoid hemorrhage (aSAH) is a life-threatening condition associated with poor outcomes. Early intervention is critical, particularly in low-volume hospitals, which are advised to transfer aSAH patients to high-volume centers. This study examines a novel protocol implemented in 2016 at Região Autónoma da Madeira, a Portuguese island. It involves the mobilization of experienced neurointerventionalists from high-volume hospitals to provide aSAH treatment. (Methods) We conducted a retrospective analysis on 30 aSAH patients who underwent endovascular treatment at the island center between November 2016 and April 2022. Additionally, we included a comparison group of 74 aSAH patients, treated with the endovascular approach at Hospital de Braga (high volume center at Portugal mainland). (Results) There was no statistical difference in patients' clinical severity between both hospitals (median WFNS score of 1). Although 90 % of patients in the novel protocol group received treatment within 3 days, we observed a significant delay compared to Hospital de Braga. Rates of aneurysm occlusion and intra-procedure complications between the two groups were similar. At the 3-months follow-up, there were no statistically significant differences between groups regarding patients that achieved a modified Rankin score of 2 or less. However, the island center exhibited a significantly higher mortality rate. (Conclusions) Overall, our results suggest that making the neurointerventionalist fly to an insular center is feasible and allows most patients to be treated within the first 72 h, as recommended. We highlight some potential recommendations for implementing this model and discuss possible causes that might justify the high mortality rate.


Aneurysm, Ruptured , Endovascular Procedures , Intracranial Aneurysm , Subarachnoid Hemorrhage , Humans , Treatment Outcome , Retrospective Studies , Subarachnoid Hemorrhage/diagnostic imaging , Subarachnoid Hemorrhage/therapy , Subarachnoid Hemorrhage/complications , Aneurysm, Ruptured/diagnostic imaging , Aneurysm, Ruptured/therapy , Aneurysm, Ruptured/complications , Endovascular Procedures/adverse effects , Endovascular Procedures/methods , Intracranial Aneurysm/diagnostic imaging , Intracranial Aneurysm/therapy , Intracranial Aneurysm/complications
8.
Materials (Basel) ; 16(2)2023 Jan 04.
Article En | MEDLINE | ID: mdl-36676223

Sol-gel production of hybrid materials has, to some extent, revolutionised materials' engineering and the way science and technology perceive the creation of new materials. Despite that, the method presents some limitations that are circumvented by radiation processing. Electron beam irradiation was used to promote synthesis of hybrid structures while using silanol-terminated PDMS, TEOS and TPOZ as precursors. Evaluation of the method's performance was executed by gel fraction determination, WDXRF and FTIR-ATR. Results showed that, although there is some pre-irradiation reactivity between precursors, radiolysis induces scission on multiple sites of precursor's structures, which induces hybrid network formation to a greater extent. Characterisation allowed determining electron beam irradiation to be effective in the creation of Si-O-Zr bonds, resulting in the production of a Class II hybrid material.

9.
Article En | MEDLINE | ID: mdl-36360810

Adolescents and young adults are an important target concerning reducing health-risk behavior adoption, including sexual health. Studying their knowledge concerning sexuality and their main counsellors, can be an important step in targeting an updated health promotion approach. This study characterized adolescents and young adults' knowledge and attitudes about sexually transmitted diseases (STDs), and contraception, prospecting for their main trusted counseling sources. We conducted a cross-sectional, population-based, self-report survey of 746 individuals aged between 14 and 24 years from Paredes, Portugal. The questionnaire included many dimensions, as demographic characteristics, youth behavior, currently sexually active status, main counselors concerning health topics, awareness, and knowledge about STDs and contraception. Mean age of the participants was 18.3 years, 50.5% of them had started their sexual activity. Males present themselves as more sexually active, starting earlier, and have more sexual partners than females. Participants reported an adequate knowledge perception about STDs and contraception methods, however we found different patterns on specific STDs and contraceptive methods, according to gender, age, and sexually active status. Our results help design specific interventions to reach youth, community, and healthcare providers, pointing out the value of bringing people to the center of health policies.


Health Knowledge, Attitudes, Practice , Sexually Transmitted Diseases , Adolescent , Male , Female , Humans , Young Adult , Adult , Cross-Sectional Studies , Portugal , Sexually Transmitted Diseases/prevention & control , Contraception , Sexual Behavior
10.
J Neuroimaging ; 32(6): 1044-1061, 2022 11.
Article En | MEDLINE | ID: mdl-35942824

Several distinct conditions present as cystic or pseudocystic lesions within the spinal canal. Some of the most common spinal cystic lesions include spinal meningeal cysts, juxtafacet cysts, dermoid/epidermoid cysts, nerve sheath tumors, and syringohydromyelia. Clinical presentation is usually nonspecific and imaging characteristics are frequently overlapping, which may pose a challenging presurgical diagnosis. We provide a pictorial review of cystic intraspinal lesions and discuss the main imaging features that can aid the neuroradiologist in the differential diagnosis. First, we propose a categorization of the lesions according to their location as extradural, intradural extramedullary, and intramedullary. This is a crucial initial step in the diagnostic workup and surgical planning. Second, for each of these locations, we organize the lesions according to their etiology: congenital and developmental disorders, degenerative disorders, traumatic or postsurgical collections, infectious conditions, neoplastic lesions, and other miscellaneous disorders. Finally, we summarize the clinical highlights and MR features that provide important insights for the differential diagnosis. MR is the technique of choice in presurgical evaluation and postsurgery follow-up. It provides accurate lesion localization and characterization and, most of the times, it will allow a confident differential diagnosis. High-resolution three-dimensional T2-weighted sequences and diffusion-weighted imaging can provide important hints in specific cases. Signal correlation with T1-weighted and fat-saturated sequences allows to differentiate true cystic lesions from hemorrhage or fat tissue.


Magnetic Resonance Imaging , Spinal Cord Diseases , Humans , Magnetic Resonance Imaging/methods , Spinal Cord Diseases/diagnostic imaging , Spinal Cord Diseases/pathology , Spine/pathology , Spinal Canal , Diffusion Magnetic Resonance Imaging , Diagnosis, Differential
11.
Lab Anim ; 56(5): 466-470, 2022 Oct.
Article En | MEDLINE | ID: mdl-35360986

The main objective of a post mortem is to identify, at a macroscopic level, any anatomical features that characterise mutant or sick mice and to describe lesions contributing to morbidity and mortality. Tissues collected for subsequent examination require appropriate handling and preservation to prevent deterioration. Therefore, efficient routine procedures are essential to facilitate histology and to ensure high-quality samples. In addition, optimised techniques minimise data loss from damaged samples reducing the numbers of animals used and supporting the 3Rs principle of reduction. Here, we describe an optimised method for tissue collection in the mouse. Training tips and points for caution are included.


Tissue Banks , Animals , Mice , Autopsy/methods , Disease Models, Animal
12.
Materials (Basel) ; 15(3)2022 Jan 27.
Article En | MEDLINE | ID: mdl-35160927

This study aimed at evaluating the effect of hydroxyapatite (HAp) nanosized structures and nanoparticles of hydrophilic silica as modifiers of both acid- and alkaline-catalysed tetraethoxysilane (TEOS)-based products for the consolidation of carbonate stones. Their initial effectiveness and some compatibility aspects were assessed in a porous limestone (sound and artificially aged Ançã stone samples) and two types of treatment (capillary absorption and brushing). The studied products were examined by scanning electron microscopy (SEM) and micro-Raman spectroscopy. Their depth of penetration and strengthening effect were evaluated through drilling resistance. Their action on the substrate was also further assessed by non-destructive methods based on colour variation and Shore-D hardness. Treated stone samples were dissimilarly affected by the tested treatments and exhibited a significant increase in strength with a low risk of over-strengthening. Adequate in-depth penetration patterns, as well as colour compatibility with the substrate were obtained with some of the prepared formulations through two types of treatment, both in sound and aged stone samples. The potential most effective treatments with the lowest colour change were obtained with the acid-catalysed TEOS-based products modified with HAp nanosized structures.

13.
Anim Reprod Sci ; 236: 106907, 2022 Jan.
Article En | MEDLINE | ID: mdl-34923194

This study was conducted to compare the effectiveness of two methodologies in evaluating B- and Doppler-mode ultrasonic images: analysis using ultrasonic software and utilizing a computer with ImageJ software. To determine if ImageJ software utilization is an efficacious alternative to ultrasonic software device- analysis, there were comparisons of values when using the two methods for morphological and vascular characteristics of follicular dynamics and luteal function in 18 crossbred cattle. From day 8 of an ovarian dynamics synchronization treatment regimen period until the time of ovulation (Day 10), B-mode and power-flow ultrasonic cineloops were obtained every 12 h to assess follicular diameter, wall area, and wall blood perfusion area. On Day 14 after ovulation, US cineloops of ovaries were obtained in B mode and power flow to evaluate various morphological and vascular characteristics of the corpus luteum (CL), including luteal diameter, luteal area, and CL blood perfusion area. Cineloops were evaluated and analyzed using ultrasonic software, and in a computer with ImageJ software. To evaluate consistency in results between the two methods, there was evaluation utilizing paired t-test, Pearson correlation coefficient, Bland-Altman plot, and Linear Regression Test procedures to calculate proportion of bias between values for measurements of variables evaluated. Results indicated none of the values for variables before and after ovulation differed (P > 0.05). It, therefore, was concluded that utilization of ImageJ software is an efficacious biomedical technique to analyze ultrasonic images of morphological and vascular characteristics before and after ovulation in cattle.


Corpus Luteum/diagnostic imaging , Image Processing, Computer-Assisted/statistics & numerical data , Ovarian Follicle/diagnostic imaging , Software , Ultrasonics/methods , Animals , Cattle , Corpus Luteum/cytology , Female , Ovarian Follicle/cytology , Ultrasonics/instrumentation
15.
Regen Biomater ; 8(1): rbaa036, 2021 Feb 01.
Article En | MEDLINE | ID: mdl-33732486

The development of injectable bone substitutes (IBS) have obtained great importance in the bone regeneration field, as a strategy to reach hardly accessible defects using minimally invasive techniques and able to fit to irregular topographies. In this scenario, the association of injectable hydrogels and bone graft granules is emerging as a well-established trend. Particularly, in situ forming hydrogels have arisen as a new IBS generation. An in situ forming and injectable dextrin-based hydrogel (HG) was developed, aiming to act as a carrier of granular bone substitutes and bioactive agents. In this work, the HG was associated to a granular bone substitute (Bonelike®) and implanted in goat critical-sized calvarial defects (14 mm) for 3, 6 and 12 weeks. The results showed that HG improved the handling properties of the Bonelike® granules and did not affect its osteoconductive features, neither impairing the bone regeneration process. Human multipotent mesenchymal stromal cells from the umbilical cord, extracellular matrix hydrolysates and the pro-angiogenic peptide LLKKK18 were also combined with the IBS. These bioactive agents did not enhance the new bone formation significantly under the conditions tested, according to micro-computed tomography and histological analysis.

16.
J Mech Behav Biomed Mater ; 116: 104337, 2021 04.
Article En | MEDLINE | ID: mdl-33516130

Chitosan has generated enormous interest in the scientific community because of its distinctive biological and physicochemical properties, which allow new advanced structures and applications. Porous chitosan scaffolds have been extensively studied and explored in bone generation, however it is still a challenge to obtain bioabsorbable orthopedic implants that involves pure 3D dense chitosan geometries due to the inherent difficulties in producing and shaping such structures. In this work, chitosan was blended with 10% glycerol and 10% glycerol + 10% biphasic mixture of calcium phosphate (70% hydroxyapatite with 30% ß-tricalcium phosphate) to produce dense chitosan-based blocks, which were then shaped into rods. The introduction of plasticizer aimed to improve the materials ductility while the ceramic particles were used to increase stiffness and strength. The mechanical behavior of the two chitosan-based compositions was evaluated by uniaxial compression tests using a customized split-Hopkinson pressure bar (SHPB). The specimens were analysed in quasi-static conditions (less than 0.1 s-1) and medium strain rate conditions (200-800 s-1), both in dry state and in different hydrated conditions, in the latter case to approximate the in vivo implant conditions. The results showed promising results for the intended application. The chitosan blends present excellent ductility with an elastic perfect-plastic behavior in quasi-static conditions, with yield stresses around 40 MPa for the dry state, with a decay for 3 MPa after 48h hydration. An empirical model was proposed to describe the flow stress curves, with a good agreement with the experimental data, allowing future modelling of this material behavior.


Absorbable Implants , Chitosan , Ceramics , Materials Testing , Porosity , Tensile Strength , Tissue Scaffolds
17.
World Allergy Organ J ; 13(9): 100456, 2020 Sep.
Article En | MEDLINE | ID: mdl-32874426

BACKGROUND & AIMS: As far as we know, no screening questionnaire has been developed and validated for identification of adverse food reactions in Portuguese-speaking adults, as an initial approach towards the investigation of cases of possible food allergy. Thus, the objective of this study was to develop and validate a screening questionnaire of food allergy in adult Portuguese-speaking patients. METHODS: This was a multicentre, cross-sectional study using a simple random sample of 186 adults between 18 and 82 years old from various parts of the centre of Portugal. Intelligibility of the questionnaire was first assessed in 24 patients with confirmed IgE- or non-IgE-mediated food allergy, and in 24 volunteers without food allergies. The 17-item questionnaire was subsequently applied by phone to 78 food allergic patients (66 IgE-mediated and 12 non-IgE mediated) and to 60 non-food allergic volunteers, with subsequent reassessment (re-test). Face and content validity, intelligibility, construct validity, and test-retest reliability (temporal stability) were analysed. RESULTS: Face and content validity allowed item reduction from 30 to 17 items with adequate content validity index >0.78. Construct validity was confirmed in the 66 confirmed IgE-mediated food allergic patients, 12 non-IgE-mediated food allergic patients, and 60 non-allergic patients. Test-Retest Reliability (general temporal stability) of the test had a Spearman correlation coefficient value of 0.845 for the retest. Cohen's Kappa values for the relevant questions were greater than 0.890 for almost all items. No differences were found when sex, age, and volunteers' recruitment origin were analysed. An inverse relationship was found between reliability and retest time interval. CONCLUSIONS: Due to the quick and easy implementation, confirmation of face, content and construct validity as well as high temporal reproducibility, this screening questionnaire may be a useful study tool for an initial approach to detection of food allergies in adults.

18.
World Allergy Organ J ; 13(8): 100453, 2020 Aug.
Article En | MEDLINE | ID: mdl-32817783

BACKGROUND & AIMS: The objective of the present study was to determine, for the first time, the prevalence and clinical features of food allergy in Portuguese adolescents. METHODS: Cross-sectional study performed in various secondary schools in central Portugal. Randomly selected adolescents replied to a validated food allergy questionnaire. Those who reported an adverse food reaction were seen at participating hospitals, where clinical history was taken, skin prick (SPT) and prick-prick skin (SPPT) tests were performed, and food allergen-specific IgE levels (sIgE) were determined. An open oral challenge was performed in selected cases. Cases of positive clinical history of immediate (up to 2 h after ingestion) reaction in association with positive food sIgE levels and/or SPT were classified as IgE-associated probable food allergy and as confirmed IgE-mediated food allergy if food challenges were positive. Cases of positive clinical history of delayed (more than 2 h after ingestion) and negative food sIgE levels independently of positive SPT or SPPT results, were classified as non-IgE associated probable food allergy. RESULTS: The prevalence of probable food allergy in Portuguese adolescents was 1.41% (95% CI: 0.90-2.03%), with fresh fruits, shellfish, nuts, and peanut as the most frequently implicated foods. IgE-mediated probable food allergy occurred in 1.23% (95% CI: 0.67-1.72%) of cases, with fresh fruits, shellfish, and nuts mainly involved. Cutaneous symptoms were most frequently reported. CONCLUSIONS: The prevalence of probable food allergies in Portuguese adolescents is low, is mostly related to fresh fruits, shellfish, nuts, and peanut, and most frequently involves cutaneous symptoms.

19.
Demetra (Rio J.) ; 15(1): e42451, jan.- mar.2020. tab, ilus
Article En, Pt | LILACS | ID: biblio-1096284

Objetivo: Avaliar a situação de segurança alimentar de famílias com crianças préescolares da zona rural de um município do Vale do Paraíba paulista. Métodos: Estudo transversal e analítico, com questionário socioeconômico, demográfico e sobre o plantio de hortas e pomares nos domicílios, além da Escala Brasileira de Insegurança Alimentar. Os dados foram tratados por meio da estatística descritiva e os testes de hipóteses seguiram nível de significância de 5%. Resultados: Participaram da pesquisa 98 mães de crianças de quatro meses a seis anos de idade, moradoras da zona rural. Verificou-se que 51% das famílias estavam em situação de insegurança alimentar, prevalecendo a forma leve. Encontrou-se associação entre insegurança alimentar e as variáveis: escolaridade materna, renda familiar e recebimento de benefício social. Conclusão: Número considerável de famílias se encontrava em situação de insegurança alimentar; os fatores associados se relacionam com a vulnerabilidade social das famílias, demonstrando a necessidade de melhoria nas condições de vida e acesso aos alimentos para as famílias. (AU)


Objective: to evaluate the situation of Food Security of families with children of primary schools in the rural areas of the Vale do Paraíba Paulista. Methods: a cross-sectional and analytical study, in which it was applied a socioeconomic and demographic questionnaire, questions about the kitchen gardens and orchards plantation's in the houses, and Brazilian Food Insecurity Scale. The data was analyzed by descriptive statistic and the hypothesis tests followed a significance level of 5%. Results: the participants were 98 mothers of children from 4 months to 6 years old, living in the countryside. It was verified that 51% of the families were in Food Insecurity, predominating the light form. It was found association between Food Insecurity and the variables: educated mothers, monthly income of the families and the receiving of social benefit. Conclusion: a considerable number of children assessed who live in the countryside are in Food Insecurity situation; the associated factors relate to the social vulnerability of families. It is necessary to take actions that in fact will improve the access to food and living situation of these families. (AU)


Humans , Female , Adult , Middle Aged , Rural Areas , Food Security , Child , Child, Preschool
20.
J Mech Behav Biomed Mater ; 103: 103572, 2020 03.
Article En | MEDLINE | ID: mdl-32090961

Bioabsorbable polymeric fixation devices have been used as an alternative to metallic implants in orthopedics, preventing the stress shielding effect and avoiding a second surgery for implant removal. However, several problems are still associated with current bioabsorbable implants, including the limited mechanical stiffness and strength, and the adverse tissue reactions generated. To minimize or even eliminate the problems associated with these implants, strategies have been developed to synthesize new implant materials based on chitosan. To overcome the brittle behavior of most 3D chitosan-based structures, glycerol and sorbitol were blended to chitosan and the effect of these plasticizers in the produced specimens was analyzed by flexural tests, Berkovich tests, scanning electron microscopy (SEM) and micro-CT analyzes. The improvement of the mechanical properties was also tested by adding ceramics, namely hydroxyapatite powder and biphasic mixtures of hydroxyapatite (HA) and beta-tricalcium phosphate (ß-TCP). In the plasticizers group, the best combination of the measured properties was obtained for chitosan with 10% glycerol (flexural strength of 53.8 MPa and indentation hardness of 19.4 kgf/mm2), while in the ceramics group the best mechanical behavior was obtained for chitosan with 10% HA+ß-TCP powder (flexural strength of 67.5 MPa and indentation hardness 28.2 kgf/mm2). All the tested material compositions were dense and homogeneous, fundamental condition for a good implant performance. These are encouraging results, which support the continued development of chitosan-based materials for orthopedic fixation applications.


Absorbable Implants , Chitosan , Orthopedics , Ceramics , Materials Testing , Microscopy, Electron, Scanning
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