Application of Zirconia in Dentistry: Biological, Mechanical and Optical Considerations

Aiming to replace the infrastructure of metallic dental prostheses, structural ceramics have been improved and increasingly used in dentistry. Among the dental ceramics, the zirconia has emerged as a versatile and promising material because of its biological, mechanical and optical properties, which has certainly accelerated the routine use of CAD/CAM technology in different types of prosthetic treatment.Routinely, zirconia based ceramics are used in structural applications in engineering as the manufacture of cutting tools, gas sensors, refractories and structural opacifiers. To meet structural demands, zirconia has to be doped with stabilizers to achieve high strength and fracture toughness. The bioceramics nowadays, used in medical and dental care, derived from structural materials used in aerospace and military armor, which were modified to suit the additional requirements of biocompatibility

YIELD AND ECONOMIC ANALYSIS OF CORN AND BRACHIARIA INTERCROPPING IN THE NORTHWESTERN PARANÁ

A consorciação de milho e Urochloa ruziziensis apresenta potencial para os sistemas de produção agrícola, permitindo a produção de grãos e biomassa remanescente. O estudo tem como objetivo avaliar a produtividade e a viabilidade econômica das modalidades de consórcio de milho e U. ruziziensis na região noroeste do Paraná. O experimento foi conduzido em Maringá-PR, em delineamento inteiramente casualizado com cinco tratamentos (milho solteiro; U. ruziziensis solteira; milho com U. ruziziensis na entre linha; milho com U. ruziziensis na mesma linha; milho com U. ruziziensis em linhas intercaladas) e quatro repetições. Foi analisado o desenvolvimento inicial e produtividade de grãos do milho, e produção de biomassa de milho e U. ruziziensis. Os dados foram submetidos a análise de variância e as médias comparadas pelo teste Tukey com significância de 5%. No desenvolvimento inicial das plantas de milho não houve diferença significativa em função da consorciação. U. ruziziensis em sistema consorciado apresentou redução na produção de biomassa. O cultivo em linhas intercaladas apresentou produtividade de grãos superior as demais modalidades de consorciação e semelhante ao cultivo de milho solteiro.The maize and Urochloa ruziziensis intercropping have potential use for agricultural production systems, allowing the production of grains and biomass. The study aims to evaluate the yield and economic viability of corn and U. ruziziensis intercropping modalities in the northwestern region of Paraná. The experiment was conducted in Maringá-PR in a completely randomized design with five treatments (single corn; single U. ruziziensis; U. ruziziensis between the corn rows; corn with U. ruziziensis in the same row; corn rows interspersed with U. ruziziensis rows) and four replicates. Initial development, grain yield of corn, and the production of biomass of corn and U. ruziziensis were evaluated. The data were submitted to analysis of variance. The means were compared by the Tukey test at 5% probability. In the initial development of corn plants, there was no significant difference due to intercropping. U. ruziziensis in the intercropped system had a reduction in biomass production. Intercropping with corn rows interspersed with U. ruziziensis rows had grain yield higher than other intercropping modalities and similar to single corn cultivatio

Fístula Cutânea Odontogénica: Um Diagnóstico a ser Lembrado pelo Médico Dermatologista

Odontogenic cutaneous fistulas occur mostly on the mandibula but we report a case due to a periapical infection of a maxillar teeth with a less frequent location: a 32 years-old female patient with an erythematous nodular lesion in the nasogenian sulcus for about 1 year that recurred after surgery. Examination of the oral cavity showed darkening of the upper arch canine tooth, ipsilateral to the skin lesion and imaging examination confirmed a periapical infection responsible for the extra-oral cutaneous fistula.As fistulas odontogénicas são mais frequentes na mandíbula, mas os autores relatam um caso de um lesão secundária a uma infecção da arcada maxilar: paciente do género feminino, 32 anos, com lesão nodular eritematosa no sulco nasogeniano, há cerca de 1 ano, com recidiva imediata após cirurgia em que o exame da cavidade oral evidenciou escurecimento do dente canino de arcada superior, ipsilateral a lesão cutânea em que o estudo imagiológico confirmou a infecção periapical do dente canino responsável pela fístula extra-oral cutânea

Imagens sobre taxonomia e sistemática zoológica, análise nos livros didáticos de biologia do PNLD 2018-2021 / Images on taxonomy and zoo systematics, analysis on the 2018-2021 PNLD biology school books

As imagens presentes nos livros didáticos quando bem utilizadas os fundamentam, proporcionam uma maior qualidade ao material e tornam-se uma importante ferramenta para auxiliar no processo de ensino aprendizagem. Nesse estudo, foram analisadas imagens relacionadas a taxonomia e sistemática zoológica encontradas nos livros didáticos de Biologia, considerou-se para a coleta de dados, as 10 coleções de livros didáticos de Biologia, ofertadas para o triênio de 2018-2021 pelo Programa Nacional do Livro Didático (PNLD).  Realizou-se análise qualitativa por meio da leitura crítica, tendo como foco critérios avaliativos estabelecidos referentes ao uso de imagens. Após essa etapa as coleções foram classificadas como: Inexistente, insatisfatórias, regulares, boas e ótimas. Verificou-se que as imagens relacionadas a classificação zoológica não seguem um padrão para todas as coleções, sendo que cada autor define uma maneira para utilizá-las. Considera-se que pesquisas como esta são importantes e necessárias, pois contribuem como ferramentas para a escolha dos livros didáticos bem como na busca da melhoria da qualidade desse recurso pedagógico

Short- and long-term reproductive effects of prenatal and lactational growth restriction caused by maternal diabetes in male rats

Background: A suboptimal intrauterine environment may have a detrimental effect on gonadal development and thereby increases the risk for reproductive disorders and infertility in adult life. Here, we used uncontrolled maternal diabetes as a model to provoke pre- and perinatal growth restriction and evaluate the sexual development of rat male offspring.Methods: Maternal diabetes was induced in the dams through administration of a single i.v. dose of 40 mg/kg streptozotocin, 7 days before mating. Female rats presenting glycemic levels above 200 mg/dL after the induction were selected for the experiment. The male offspring was analyzed at different phases of sexual development, i.e., peripuberty, postpuberty and adulthood.Results: Body weight and blood glucose levels of pups, on the third postnatal day, were lower in the offspring of diabetic dams compared to controls. Maternal diabetes also provoked delayed testicular descent and preputial separation. In the offspring of diabetic dams the weight of reproductive organs at 40, 60 and 90 days-old was lower, as well as sperm reserves and sperm transit time through the epididymis. However the plasma testosterone levels were not different among experimental groups.Conclusions: It is difficult to isolate the effects directly from diabetes and those from IUGR. Although the exposure to hyperglycemic environment during prenatal life and lactation delayed the onset of puberty in male rats, the IUGR, in the studied model, did not influenced the structural organization of the male gonads of the offspring at any point during sexual development. However the decrease in sperm reserves in epididymal cauda and the acceleration in sperm transit time in this portion of epididymis may lead to an impairment of sperm quality and fertility potential in these animals. Additional studies are needed in attempt to investigate the fertility of animals with intrauterine growth restriction by maternal diabetes and possible multigenerational effects

Exposição à mistura de vitamina C, hesperidina e piperidol durante a gravidez: repercussões materno-fetais

Para avaliar a performance reprodutiva de ratas e o desenvolvimento de seus filhotes, ratas Wistar prenhes foram tratadas por gavage com 0 mg/kg peso corpóreo/dia (grupo controle, n = 20) e 166,5 mg/kg/dia de mistura de vitamina C, hesperidina e piperidol (grupo experimental, n= 20) durante o período organogênico (do 5º ao 14º dia de prenhez, considerando esfregaço vaginal positivo = dia 1). As ratas foram mortas no 21º dia de prenhez. O número de implantações, reabsorções (morte embrionária) e os fetos vivos e mortos foram contados para avaliação da taxa de perda pós-implantação. Não houve alteração na performance reprodutiva materna, mas foi verificado aumento no número de fetos com uretér dilatado, hidronefrose e ossificação reduzida do crânio devido ao tratamento das ratas com a mistura de vitamina C, hesperidina e piperidol. Essas anormalidades foram consideradas transitórias e não interfeririam no desenvolvimento dos filhotes. Não foram observados outros tipos de malformações amiores e os fetos também apresentaram atrofia dos membros superiores que pudesse estar relacionado ao uso desta mistura.To evaluate the reproductive performance and the development of their offspring on rat pregnancy, Wistar pregnant rats were gavaged with 0 mg/kg wb/day (control group, n = 20) and 166.5 mg/kg/day of a mixture of vitamin C, hesperidin and piperidol (experimental group, n= 20) during the organogenic period (from day 5 to 14 of pregnancy; positive vaginal smear = day 0). The female rats were killed on day 21 of pregnancy. The number of implantations, resorptions (dead embryos), and live/dead fetuses were counted for the analysis of the postimplantation loss rates. There was neither alteration in maternal reproductive performance, but it was verified an increase of the number of fetuses presenting dilated urether, hydronephrosis, and reduced ossification of skull due to the treatment of female rats with a mixture of vitamin C, hesperidin and piperidol, these abnormalities were considered transitory and may not interfere on offspring development. It was not verified other type of major malformation neither the appearance of fetuses presenting atrophy of upper limbs that it could be associated to use of this drug

Methylparaben concentration in commercial Brazilian local anesthetics solutions

OBJECTIVE: To detect the presence and concentration of methylparaben in cartridges of commercial Brazilian local anesthetics. MATERIAL AND METHODS: Twelve commercial brands (4 in glass and 8 in plastic cartridges) of local anesthetic solutions for use in dentistry were purchased from the Brazilian market and analyzed. Different lots of the commercial brands were obtained in different Brazilian cities (Piracicaba, Campinas and São Paulo). Separation was performed using high performance liquid chromatography (HPLC) with UV-Vis detector. The mobile phase used was acetonitrile:water (75:25 - v/v), pH 4.5, adjusted with acetic acid at a flow rate of 1.0 ml.min-1. RESULTS: When detected in the solutions, the methylparaben concentration ranged from 0.01% (m/v) to 0.16% (m/v). One glass and all plastic cartridges presented methylparaben. CONCLUSION: 1. Methylparaben concentration varied among solutions from different manufacturers, and it was not indicated in the drug package inserts; 2. Since the presence of methylparaben in dental anesthetics is not regulated by the Brazilian National Health Surveillance Agency (ANVISA) and this substance could cause allergic reactions, it is important to alert dentists about its possible presence

Comparison of lots of pea seeds produced in northwest of Paraná

The establishment of the crop demands the use of seeds that allow the plants to perform better in adverse conditions. The study aimed to compare lots of pea seeds produced in the northwestern region of Paraná. The experiment was carried out in a completely randomized design with seven seed lots and four replications. The seeds were obtained in field production, with similar management conditions. The determination of the weight of a thousand seeds, water content, electrical conductivity, percentage of germination, fresh and dry mass of the aerial part and root of the seedlings performed. The data were subjected to analysis of variance and the means compared by the Tukey test with 5% significance. The physiological potential not directly related to the seed mass; of the pea lots produced under adverse conditions, lots L3 and L4 showed superior quality. The physiological tests of electrical conductivity and germination differentiated the quality of the seeds. According to the selection criteria, the seeds of four pea lots showed germination higher than 85%, being the seeds of the lot L3 and L4 presented superior quality

Nutrientes em sementes de soja em função da aplicação de zinco

Esse trabalho teve como objetivo analisar o acúmulo de nutrientes em sementes de soja em função da aplicação de zinco (Zn) no solo e foliar. O trabalho foi desenvolvido à campo, no ano agrícola de 2018/2019, em delineamento inteiramente casualizado, com onze tratamentos e quatro repetições. Os tratamentos consistiram em aplicações de Zn no solo (T1: controle; T2: 8; T3: 16; T4:32; T5:48 e T6: 64 Kg ha-1) e foliar (T7:4; T8:8; T9:12; T10:16 e T11: 24 Kg ha-1) associadas a 4 Kg ha-1 no solo. A aplicação de Zn foi realizada no inicio da formação de vagens (estádio R3), utilizando sulfato de zinco. Foram coletadas sementes, ao fim do ciclo da cultura, e determinado o acúmulo de nutrientes (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Mo e Zn). Os dados foram analisando utilizando o teste de Scott-Knott (p<0,05) para comparação de médias, os teores entre nutrientes foram correlacionados, e  realizada regressão para  acúmulo de Zn. A aplicação de Zn nas diferentes formas e doses adotadas, influenciaram significativamente no acumulo dos nutrientes analisados, principalmmente no teor de N. O acúmulo de Zn é crescente acompanhando o incremento da quantidade aplicada. Aplicações associadas, solo e foliar, apresentaram maior eficiencia em relação ao acumulo de Zn nas sementes.

Effects of exposure to cigarette smoke prior to pregnancy in diabetic rats

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to evaluate the effects of cigarette smoke exposure before pregnancy on diabetic rats and their offspring development.</p> <p>Methods</p> <p>Diabetes was induced by streptozotocin and cigarette smoke exposure was conducted by mainstream smoke generated by a mechanical smoking device and delivered into a chamber. Diabetic female Wistar rats were randomly distributed in four experimental groups (n minimum = 13/group): nondiabetic (ND) and diabetic rats exposed to filtered air (D), diabetic rats exposed to cigarette smoke prior to and into the pregnancy period (DS) and diabetic rats exposed to cigarette smoke prior to pregnancy period (DSPP). At day 21 of pregnancy, rats were killed for maternal biochemical determination and reproductive outcomes.</p> <p>Results</p> <p>The association of diabetes and cigarette smoke in DSPP group caused altered glycemia at term, reduced number of implantation and live fetuses, decreased litter and maternal weight, increased pre and postimplantation loss rates, reduced triglyceride and VLDL-c concentrations, increased levels of thiol groups and MDA. Besides, these dams presented increased SOD and GSH-Px activities. However, the increased antioxidant status was not sufficient to prevent the lipid peroxidation observed in these animals.</p> <p>Conclusion</p> <p>Despite the benefits stemming from smoking interruption during the pregnancy of diabetic rats, such improvement was insufficient to avoid metabolic alterations and provide an adequate intrauterine environment for embryofetal development. Therefore, these results suggest that it is necessary to cease smoking extensive time before planning pregnancy, since stopping smoking only when pregnancy is detected may not contribute effectively to fully adequate embryofetal development.</p