Shotgun proteomics profiling of chia seeds (Salvia hispanica L.) reveals genotypic differential responses to viability loss.

Introduction: Exposure to elevated temperatures and relative humidity expedites the seed aging process, finally leading to seed viability loss. In this context, certain proteins play a pivotal role in safeguarding the longevity of seeds. However, the seedproteomic response to loss viability in Salvia hispanica L., commonly known as chia, remains incompletely understood. Methods: This work explores the application of proteomics as a potent tool for uncovering molecular responses to viability loss caused by artificial aging in two chia genotypes, WN and MN. Results: By using a quantitative label-free proteomics analysis (LC-MS/MS), 1787 proteins wereidentified in chia seeds at a 95% confidence level, including storage proteins, heat shock proteins (HSPs), late embryogenesis abundant proteins (LEA),oleosins, reactive oxygen species (ROS)-related enzymes, and ribosomal proteins. A relatively low percentage of exclusive proteins were identified in viable and non-viable seeds. However, proteins exhibiting differential abundancebetween samples indicated variations in the genotype and physiological status. Specifically, the WN genotype showed 130 proteins with differential abundancecomparing viable and non-viable seeds, while MN displayed changes in the abundance of 174 proteins. While both showed a significant decrease in keyproteins responsible for maintaining seed functionality, longevity, and vigor withhigh-temperature and humidity conditions, such as LEA proteins or HSPs, ROS, and oleosins, distinct responses between genotypes were noted, particularly in ribosomal proteins that were accumulated in MN and diminished in WN seeds. Discussion: Overall, the results emphasize the importance of evaluating changes in proteins of viable and non-viable seeds as they offer valuable insights into the underlying biological mechanisms responsible for the maintenance of chia seed integrity throughout high-temperature and humidity exposure.

Controlled deterioration test to evaluate the physiological potential of sweet corn seeds / Teste de deterioração controlada para avaliação do potencial fisiológico de sementes de milho doce

The evaluation of the physiological potential of sweet corn seeds is essential in a quality control program and the choice of vigor tests using an adequate analysis methodology is essential to obtain reliable results. In this sense, this study aimed to standardize the methodology of the controlled deterioration test through combinations between time and temperature to evaluate the vigor of sweet corn seeds. Six lots of sweet corn seeds were characterized by the degree of moisture and the initial physiological potential through the following tests: germination, first germination count, cold test, electrical conductivity, accelerated aging, length and dry mass of normal seedlings, seedling emergence in sand, and emergence rate index. Subsequently, these lots had their initial water content adjusted to 20% using the wet substrate method. The seeds from the six lots were subjected to the controlled deterioration test under two temperatures for four periods, obtaining a completely randomized design in an 8 × 6 factorial scheme with eight combinations of time/temperature and six lots. Germination and the first germination count were evaluated after the deterioration test. The data were subjected to analysis of variance with a comparison of means by the Tukey test at a 5% significance. The results of the first count and germination tests after deterioration were subjected to a simple linear correlation study together with the initial characterization data. The combinations 8 h ­ 40 °C and 8 h ­ 45 °C in the controlled deterioration test were efficient in distinguishing the vigor of seed lots. The shorter exposure period and the first germination count after deterioration are more suitable for evaluating the vigor of sweet corn seeds.(AU)

A avaliação do potencial fisiológico de sementes de milho doce é essencial em um programa de controle de qualidade e, a escolha de testes de vigor com uma metodologia de análise adequada é fundamental para a obtenção de resultados confiáveis. Neste sentido, objetivou-se padronizar a metodologia do teste de deterioração controlada, por meio de combinações de tempo e temperatura, para avaliação do vigor de sementes de milho doce. Foram utilizados seis lotes de sementes de milho doce, caracterizados quanto o grau de umidade e o potencial fisiológico inicial por meio dos seguintes testes: germinação, primeira contagem da germinação, teste de frio, condutividade elétrica, envelhecimento acelerado, comprimento e massa seca de plântulas normais, emergência de plântulas em areia e índice de velocidade de emergência. Posteriormente, esses lotes tiveram o teor de água inicial ajustado para 20%, pelo método do substrato úmido. Em seguida, sementes dos seis lotes foram submetidas ao teste de deterioração controlada sob duas temperaturas, por quatro períodos, obtendo-se um delineamento inteiramente casualizado em esquema fatorial 8 × 6, sendo 8 combinações de tempo/temperatura e 6 lotes. Após o teste de deterioração, foram avaliadas a germinação e a primeira contagem da germinação. Os dados obtidos foram submetidos à análise de variância com comparação de médias pelo teste de Tukey a 5% de significância e, por fim, os resultados dos testes de primeira contagem e germinação após a deterioração, foram submetidos a estudo de correlação linear simples, juntamente com os dados da caracterização inicial. As combinações 8h ­ 40°C e 8h ­ 45°C, no teste de deterioração controlada, foram eficientes na distinção do vigor dos lotes de sementes. O menor período de exposição e a primeira contagem da germinação, após a deterioração, são mais indicados para a avaliação do vigor de sementes de milho doce.(AU)

Evaluation of fracture resistance of zirconia monolithic restorations: an in vitro study / Avaliação da resistência à fratura de restaurações monolíticas de zircônia: um estudo in vitro

Objective: was to evaluate fracture resistance of zirconia monolithic restorations after aging procedures. Material and methods: Monolithic translucent zirconia 3-unit FPDs were fabricated using Cerec inLab CAD/CAM system on 2 stainless steel dies with a uniform 120 degrees circumferential deep chamfer finish line of 1 mm width. FPDs were divided into 2 groups, first group (Group A) was subjected to aging procedures in an autoclave at hydrothermal conditions 134 oC /2 bars for 5 hours. Second group (Group B) was not subjected to any aging procedures (control group). All specimens of each group were loaded compressively in a universal testing machine at cross head speed 0.5 mm/min until fracture occurred. The percentage of monoclinic (m) phase was detected by XRD device. Scanning electron microscope (SEM) was used to examine the fractured surfaces for Aged TZI (Group A) and Non-aged TZI (Group B). Student's t-test was used to compare between fracture resistances of both groups. The significance level was set at P ≤ 0.05. Results: The fracture resistance mean (SD) values of non-aged TZI (Group B) was 2406.9 ± 306.8 N which showed statistically significantly higher than that of aged group (Group A) which was 1964.5 ± 234.5 N. The percentage of monoclinic (m) phase detected by XRD device software in non-aged TZI (Group B) was nearly 0 weight % and in aged TZI (Group A) was about 42 weight %. Conclusions:Accelerated artificial aging decreases the fracture resistance of monolithic TZI FPDs. (AU)

Objetivo: Foi avaliar a resistencia à fratura de restaurações de zircônia monolítica após procedimentos de envelhecimento.Material e Métodos: 3 unidades de FPDs de zircônia monolítica translucida foram fabricadas utilizando o sistema Cerec inLab CAD/CAM com 2 matrizes de aço inoxidável com uma linha de acabamento de chanfro profundo circunferencial de 120 graus de largura de 1 mm. As FPDs foram divididos em dois grupos, primeiro grupo (Grupo A) foi submetido a procedimentos de envelhecimento em autoclave em condições hidrotérmicas de 134 °C /2 bars por 5 horas. O segundo grupo (Grupo B) não foi submetido a nenhum processo de envelhecimento (grupo controle). Todos os espécimes de cada grupo foram carregados compressivamente em uma maquina de teste universal na velocidade de 0.5 mm/min até a fratura ocorrer. A porcentagem da fase monoclínica (m) foi detectada pelo dispositivo XRD. O microscópio eletrônico de varredura (MEV) foi utilizado para examinar as superfícies fraturadas para TZI envelhecido (Grupo A) e TZI não envelhecido (Grupo B). O teste t de estudantes foi usado para comparar as resistências à fraturas de ambos os grupos. O nível de significância foi estabelecido em P ≤ 0.05. Resultados: Os valores médios de resistência à fratura (SD) do TZI não envelhecido (Grupo B) foi 2406.9±306.8 N, o qual se mostrou estatisticamente significativamente maior do que o grupo envelhecido (Grupo A), que foi 1964.5±234.5 N. A porcentagem da fase monoclínica (m) detectada pelo software do dispositivo XRD em TZI não envelhecido (Grupo B) foi próximo de 0% em peso e em TZI envelhecido (Grupo A) foi cerca de 42% em peso. Conclusão: O envelhecimento artificial acelerado diminui a resistência à fratura de FPDs TZI monolítico (AU)

Influence of surface sealing on color stability and roughness of composite submitted to ultraviolet-accelerated aging.

AIM: In the present study, we evaluated the influence of surface sealing on color stability and surface roughness of a composite resin after accelerated artificial aging. METHODS: Thirty-two specimens of a composite were prepared. After 24 h, the specimens were polished and divided into four groups (n = 8), according to the surface sealant used, including the control, which had no sealant application. Baseline color was measured according to the CIELab system using a reflection spectrophotometer. Surface roughness was determined using a profilometer with a cut-off of 0.25 mm. After these tests, specimens were aged for 252 h in an ultraviolet (UV)-accelerated aging chamber. Color stability was determined by difference between coordinates obtained before and after the aging procedure. Data of color change and roughness were evaluated by anova and Fisher's exact test (α = 0.05). RESULTS: The results showed that the unsealed group had the highest color change compared to other groups (P = 0.0289), and there was no significant difference between groups sealed with surface sealant (P > 0.05). The artificial aging caused an increase in roughness values independent of the experimental group studied (P = 0.0015). CONCLUSION: The sealed composites showed lower color change after UV aging, but all groups showed clinically-acceptable color change, and only liquid polish decreased roughness.

Action of exogenous ascorbic acid on physiological quality of cowpea seeds artificially aged / Ação do ácido ascórbico exógeno na qualidade fisiológica de sementes de feijão de corda envelhecidas artificialmente

The aim of this study was to evaluate the effects of pre-treatment and post-treatment with ascorbic acid in reducing the damage caused by aging in cowpea seeds, which were aged in artificial accelerated aging chamber (45C, 99% relative humidity in the dark) for 72 h and it were subjected to four treatments: T1 non-aged seeds were not treated with ascorbic acid (AsA); T2 non-aged seeds treated with AsA; T3 seeds before aging were subjected to a treatment with AsA to 0.85 mM; T4 seeds after aging were subjected to a treatment with a 0.85 mM AsA. The aging of seeds for 72 h (T2) caused significant damage in the cell membranes of cowpea seeds, as evidenced by a increase in electrolyte leakage, higher level of lipid peroxidation and a lower germination percentage, when compared with the control (T1). T4 results were like the control treatment, with a lower electrolyte leakage and lipid peroxidation, well as a higher germination percentage, when compared with T2. The exogenous application of 0.85 mM ascorbic acid in cowpea seeds after artificial aging can mitigate its detrimental effects on the membranes integrity and seed physiological quality.

O objetivo desse estudo foi avaliar os efeitos do pré e pós-tratamento com ácido ascórbico na redução dos danos ocasionados pelo envelhecimento em sementes de feijão de corda, as quais foram envelhecidas em câmara de envelhecimento artificial (45 ºC, 99% U.R., no escuro) por 72 h, sendo submetidas a quatro tratamentos: T1 sementes não envelhecidas e não tratadas com ácido ascórbico (AsA); T2 sementes envelhecidas e não tratadas com AsA; T3 sementes que antes do envelhecimento foram submetidas a um tratamento com AsA a 0,85 mM; T4 sementes que após o envelhecimento foram submetidas a um tratamento com AsA a 0,85 mM. O envelhecimento das sementes por 72 h (T2) provocou danos significativos nas membranas celulares das sementes de feijão de corda, como foi evidenciado pelo aumento no vazamento de eletrólitos, maior nível de peroxidação de lipídios e menor porcentagem de germinação quando comparado com o controle (T1). O T4 conseguiu igualar aos resultados apresentados pelo controle, apresentando um menor vazamento de eletrólitos e peroxidação de lipídios, bem como maior germinação, quando comparado com o T2. A aplicação exógena de ácido ascórbico a 0,85 mM nas sementes de feijão de corda após o envelhecimento artificial pode atenuar efeitos deletérios na integridade de membranas e favorecer a qualidade fisiológica das sementes.

Action of exogenous ascorbic acid on physiological quality of cowpea seeds artificially aged / Ação do ácido ascórbico exógeno na qualidade fisiológica de sementes de feijão de corda envelhecidas artificialmente

The aim of this study was to evaluate the effects of pre-treatment and post-treatment with ascorbic acid in reducing the damage caused by aging in cowpea seeds, which were aged in artificial accelerated aging chamber (45C, 99% relative humidity in the dark) for 72 h and it were subjected to four treatments: T1 non-aged seeds were not treated with ascorbic acid (AsA); T2 non-aged seeds treated with AsA; T3 seeds before aging were subjected to a treatment with AsA to 0.85 mM; T4 seeds after aging were subjected to a treatment with a 0.85 mM AsA. The aging of seeds for 72 h (T2) caused significant damage in the cell membranes of cowpea seeds, as evidenced by a increase in electrolyte leakage, higher level of lipid peroxidation and a lower germination percentage, when compared with the control (T1). T4 results were like the control treatment, with a lower electrolyte leakage and lipid peroxidation, well as a higher germination percentage, when compared with T2. The exogenous application of 0.85 mM ascorbic acid in cowpea seeds after artificial aging can mitigate its detrimental effects on the membranes integrity and seed physiological quality.

O objetivo desse estudo foi avaliar os efeitos do pré e pós-tratamento com ácido ascórbico na redução dos danos ocasionados pelo envelhecimento em sementes de feijão de corda, as quais foram envelhecidas em câmara de envelhecimento artificial (45 ºC, 99% U.R., no escuro) por 72 h, sendo submetidas a quatro tratamentos: T1 sementes não envelhecidas e não tratadas com ácido ascórbico (AsA); T2 sementes envelhecidas e não tratadas com AsA; T3 sementes que antes do envelhecimento foram submetidas a um tratamento com AsA a 0,85 mM; T4 sementes que após o envelhecimento foram submetidas a um tratamento com AsA a 0,85 mM. O envelhecimento das sementes por 72 h (T2) provocou danos significativos nas membranas celulares das sementes de feijão de corda, como foi evidenciado pelo aumento no vazamento de eletrólitos, maior nível de peroxidação de lipídios e menor porcentagem de germinação quando comparado com o controle (T1). O T4 conseguiu igualar aos resultados apresentados pelo controle, apresentando um menor vazamento de eletrólitos e peroxidação de lipídios, bem como maior germinação, quando comparado com o T2. A aplicação exógena de ácido ascórbico a 0,85 mM nas sementes de feijão de corda após o envelhecimento artificial pode atenuar efeitos deletérios na integridade de membranas e favorecer a qualidade fisiológica das sementes.

Composites associated with pulp-protection material: color-stability analysis after accelerated artificial aging.

OBJECTIVES: This study assessed the color stability of two composites associated with two pulp protectors submitted to accelerated artificial aging (AAA). METHODS: 60 test specimens were made with 0.5 mm of protection material (calcium hydroxide - CH or glass ionomer cement - GIC) and 2.5 mm of restoration material (Concept or QuixFil) and divided into 3 groups (n=10) according to the type of protection material/composite, and the control group (no protection). After polishing, color readings were obtained with a spectrophotometer (PCB 6807 Byk Gardner) before and after AAA for 384 hours, and L*, a*, and b* coordinates and total color variation (DeltaE) were analyzed (2-way ANOVA, Bonferroni, alpha=05). RESULTS: Composites placed on CH presented lower L* levels than those on GIC, which presented higher L* values than the control group and lower b* values than those of the CH group. The Concept composite presented higher DeltaE levels for all groups, differing statistically from QuixFil, except when placed on GIC. CONCLUSIONS: It was concluded that the protection material could affect the color stability and AAA is a factor that enhances this effect, depending on the type of composite used.