RESUMO
AIM: To evaluate the influence of ultraconservative endodontic access cavities (UEC) and the use of instruments with various tapers (.03 or .05) and tip diameters (25 or 40) on the ability to shape canals in mandibular molars and their fracture resistance in comparison with traditional endodontic access cavities (TEC). METHODOLOGY: Thirty-two intact extracted mandibular molars were scanned in a micro-computed tomography device, matched based on similar anatomical features and assigned to UEC or TEC groups and to subgroups according to mechanical canal preparation with Bassi Logic™ rotary NiTi instruments with .03 or .05 taper (n = 8 per group). The teeth were mounted onto a mannequin head, and the pulp chambers were accessed and the root canals subjected to instrumentation. In the first stage, size 25 endodontic instruments were used, with .03 or .05 tapers. The teeth were re-scanned. Subsequently, a second canal instrumentation was performed with the size 40 instruments with .03 or .05 tapers and scanned again. The root canals were filled and then the teeth restored before being subjected to fracture resistance tests. The data on untouched canal areas, canal transportation, centring ability, the percentage of removed dentine and maximum load at fracture were analysed. One-way anova and Tukey's tests were performed for inter-group analysis. The paired-samples t-test was performed on the results between size 25 and size 40 apical preparations for each individual specimen (P < 0.05). RESULTS: No significant difference was observed for the percentage of untouched canal area when comparing UEC and TEC groups or between the .03 and .05 tapers with the same instrument tip size (P > 0.05). There was a significantly lower percentage of untouched canal area after instrumentation with size 40 instruments when compared to size 25 (P < 0.05). No significant difference in the percentage of dentine removed was observed between the access cavities or the different tapers (P > 0.05). Size 40 apical preparations removed significantly more dentine than size 25 preparations (P < 0.05). No significant differences were observed in canal transportation, centring ability and fracture resistance in any of the tested groups (P > 0.05). CONCLUSIONS: Ultraconservative endodontic access cavities did not offer any advantages in comparison with traditional endodontic access cavities on the ability to shape canals, nor the fracture resistance of mandibular molars. No differences were observed in shaping ability and fracture resistance between .03 and .05 taper canal preparations. Apical preparation with larger instruments resulted in significantly less untouched canal area in all groups.
Assuntos
Cavidade Pulpar , Laboratórios , Cavidade Pulpar/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Dente Molar/cirurgia , Preparo de Canal Radicular , Microtomografia por Raio-XRESUMO
Fish processing provides waste of around 50.0% to 70.0% of the animal's initial weight, especially the skin. Thus, this residue contains the by-product that allows biopolymers to be obtained, highlighting collagen, which can be widely used in different areas. The present study aimed to evaluate the yield of collagen extracted from peacock bass Cichla monoculus skin and to characterize them physicochemically. Twenty-five peacock bass with an average weight of 646 ± 175 g were used. The skin samples were removed by manual filleting and weighed, with an average yield of 3.7%. Subsequently, such models were analyzed for chemical composition, showing 61.8% for moisture, 29.3% for crude protein, 1.5% for ash, 6.3% for total lipids, and 1.2% for non-nitrogenous extract (NNE). Acid-soluble collagen (ASC) presented an average yield of 8.2%, presenting in its analysis of centesimal composition 12.5% ââof moisture, 82.6% of crude protein, 1.1% of ash, 2.6% of total lipids, and 1.2% NNE. The skin and collagen extracted from the tucunaré skin have technological potential for use in the preparation of products, adding value to these by-products from fish processing.
Assuntos
Ciclídeos , Animais , Colágeno , LipídeosRESUMO
Fishing plays a prominent role in the socioeconomic scope of the Negro River basin and is considered one of the main extractive activities in the region. The objective of this study was to describe the socioeconomic aspects of commercial fishers of edible fish who work in the municipality of Barcelos, in the middle Negro River region, as well as to highlight the scenario of the fishing activity from the point of view of the fishers. The information was collected between January and December 2016 in the municipality of Barcelos, state of Amazonas, via semi-structured questionnaires. Most interviewees were male (71.14%), aged between 18 and 82 years and a mean age of 48 years. With a low level of education, 45.0% had only incomplete elementary education and 15% were illiterate. The fishing tackle most used by fishermen was the gillnet, especially by urban fishermen (70%). Among the fishing sites, the main one was the Demeni River (50%). Commercial fishing for edible fish in Barcelos focused on Characiformes, Perciformes and Siluriformes fish. The main difficulties faced by the activity are related to the seasonality of the level of rivers and local tributaries, as well as the lack of buyers and low selling price of fish, in addition to conflicts over the use of fishing resources. Commercial fishing for edible fish is an activity of great socioeconomic importance for riverside families in the Middle River Negro basin, which needs greater attention from the public authorities. Therefore, it is expected that the information contained in this study can help in the decision-making process for the management of local fisheries resources and contribute to the resumption of growth and sustainability of commercial edible fish fisheries.
Assuntos
Conservação dos Recursos Naturais , Rios , Humanos , Animais , Masculino , Feminino , Brasil , Negro ou Afro-Americano , Caça , Pesqueiros , Fatores Socioeconômicos , PeixesRESUMO
During germination, orthodox seeds become gradually intolerant to desiccation, and for this reason, they are a good model for recalcitrance studies. In the present work, physiological, biochemical, and ultrastructural aspects of the desiccation tolerance were characterized during the germination process of Anadenanthera colubrina seeds. The seeds were imbibed during zero (control), 2, 8, 12 (no germinated seeds), and 18 hours (germinated seeds with 1 mm protruded radicle); then they were dried for 72 hours, rehydrated and evaluated for survivorship. Along the imbibition, cytometric and ultrastructural analysis were performed, besides the extraction of the heat-stable proteins. Posteriorly to imbibition and drying, the evaluation of ultrastructural damages was performed. Desiccation tolerance was fully lost after root protrusion. There was no increase in 4C DNA content after the loss of desiccation tolerance. Ultrastructural characteristics of cells from 1mm roots resembled those found in the recalcitrant seeds, in both hydrated and dehydrated states. The loss of desiccation tolerance coincided with the reduction of heat-stable proteins.
Assuntos
Dessecação , Fabaceae/fisiologia , Germinação , Fabaceae/genética , Fabaceae/crescimento & desenvolvimento , Fabaceae/ultraestrutura , Proteínas de Plantas/metabolismo , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/fisiologia , Sementes/ultraestrutura , Árvores/genética , Árvores/crescimento & desenvolvimento , Árvores/fisiologia , Árvores/ultraestruturaRESUMO
Histoplasmosis is caused by the dimorphic fungus Histoplasma capsulatum. It manifests by the presence of fever as the only symptom in most individuals. The disease may present as self-limited pneumonia, or as an hematogenous widespread fungal infection with a potentially fatal outcome in elderly individuals and people with compromised T-cell mediated immunity. Here, we report a case of disseminated cutaneous histoplasmosis in a patient with AIDS. The patient was a 33 year old male homosexual, intravenous drug user, who had been diagnosed with HIV infection 5 years earlier. He was in good health, but had erythematous papules and pustules in the skin of the scalp, face, back, thighs, abdomen, palms, and soles. He was placed on anti-retroviral therapy, fluconazole for mucosal candidiasis, trimethoprim/sulfamethoxazole for pneumocystis prophylaxis, and antibiotics for the skin pustules. The skin lesions improved remarkably within 14 days. He was discharged and soon lost to follow-up. After his discharge, skin biopsy and fungal culture results revealed H. capsulatum. He was seen again 1 year later. The interim history revealed that he had taken fluconazole 100 mg/day for 1 month and fluconazole 150 mg/week for 7 months. He had not continued anti-retroviral therapy, nor taken other antifungal drugs. The clinical evolution of the disease was exceptional in that there was disappearance of all the skin lesions attributed to histoplasmosis with fluconazole. Although itraconazole remains the drug of choice for histoplasmosis. Cutaneous histoplasmosis should be considered in the differential diagnosis of atypical cutaneous lesions in individuals infected with HIV.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Dermatomicoses/diagnóstico , Histoplasma/isolamento & purificação , Histoplasmose/diagnóstico , Adulto , Dermatomicoses/microbiologia , Histoplasmose/microbiologia , Humanos , MasculinoRESUMO
Abstract During germination, orthodox seeds become gradually intolerant to desiccation, and for this reason, they are a good model for recalcitrance studies. In the present work, physiological, biochemical, and ultrastructural aspects of the desiccation tolerance were characterized during the germination process of Anadenanthera colubrina seeds. The seeds were imbibed during zero (control), 2, 8, 12 (no germinated seeds), and 18 hours (germinated seeds with 1 mm protruded radicle); then they were dried for 72 hours, rehydrated and evaluated for survivorship. Along the imbibition, cytometric and ultrastructural analysis were performed, besides the extraction of the heat-stable proteins. Posteriorly to imbibition and drying, the evaluation of ultrastructural damages was performed. Desiccation tolerance was fully lost after root protrusion. There was no increase in 4C DNA content after the loss of desiccation tolerance. Ultrastructural characteristics of cells from 1mm roots resembled those found in the recalcitrant seeds, in both hydrated and dehydrated states. The loss of desiccation tolerance coincided with the reduction of heat-stable proteins.
Resumo Durante a germinação, sementes ortodoxas tornam-se gradualmente intolerantes à dessecação, e por isso podem ser utilizadas como modelo para o estudo da recalcitrância. No presente trabalho realizou-se uma caracterização dos aspectos fisiológicos, bioquímicos e ultraestruturais da perda da tolerância à dessecação de sementes de Anadenanthera colubrina em processo germinativo. Para isso as sementes foram embebidas durante 0 (controle), 2,8,12 e aproximadamente 18 horas (sementes germinadas com 1 mm de radícula), secas por 72 horas, reidratadas e a sobrevivência avaliada. Ao longo da embebição foram realizadas análises citométricas, ultraestruturais e extração de proteínas resistentes ao calor e após embebição e secagem foram avaliados danos ultraestruturais. A tolerância à dessecação foi totalmente perdida após a protrusão radicular. Não houve aumento do conteúdo de DNA 4C quando a tolerância à dessecação foi perdida. Características ultraestruturais de células de radículas de 1 mm assemelharam-se às encontradas em sementes recalcitrantes tanto no estado hidratado quanto desidratado. A perda da tolerância à dessecação coincidiu com a redução do conteúdo de proteínas resistentes ao calor.
Assuntos
Germinação , Dessecação , Fabaceae/fisiologia , Proteínas de Plantas/metabolismo , Sementes/crescimento & desenvolvimento , Sementes/fisiologia , Sementes/genética , Sementes/ultraestrutura , Árvores/crescimento & desenvolvimento , Árvores/fisiologia , Árvores/genética , Árvores/ultraestrutura , Fabaceae/crescimento & desenvolvimento , Fabaceae/genética , Fabaceae/ultraestruturaRESUMO
Histoplasmosis is caused by the dimorphic fungus Histoplasma capsulatum. It manifests by the presence of fever as the only symptom in most individuals. The disease may present as self-limited pneumonia, or as an hematogenous widespread fungal infection with a potentially fatal outcome in elderly individuals and people with compromised T-cell mediated immunity. Here, we report a case of disseminated cutaneous histoplasmosis in a patient with AIDS. The patient was a 33 year old male homosexual, intravenous drug user, who had been diagnosed with HIV infection 5 years earlier. He has in good health, but had erythematous papules and pustules in the skin of the scalp, face, back, thighs, abdomen, palms, and soles. He was placed on anti-retroviral therapy, fluconazole for mucosal candidiasis, trimethoprim/sulfamethoxazole for pneumocystis prophylaxis, and antibiotics for the skin pustules. The skin lesions improved remarkably within 14 days. He was discharged and soon lost to follow-up. After his discharge, skin biopsy and fungal culture results revealed H. capsulatum. He was seen again 1 year later. the interim history revealed that he had taken fluconazole 100 mg/day for 1 month and fluconazole 150 mg/week for 7 months. He had not continued anti-retroviral therapy, nor taken other antifungal drugs. The clinical evolution of the disease was exceptional in that there was disappearance of all the skin lesions attributed to histoplasmosis with fluconazole. Although itraconazole remains the drug of choice for histoplasmosis. Cutaneous histoplasmosis should be considered in the differential diagnosis of atypical cutaneous lesions in individuals infected with HIV.