Transferência de tecnologia ou compartilhamento de conhecimentos?: desvendando o papel da Embrapa no desenvolvimento rural.

Caminhos da pesquisa; Busca de um novo perfil: estratégias de transferência de tecnologia e compartilhamento de conhecimentos adotadas pela Embrapa; Avaliação dos canais de comunicação utilizados pelas Unidades.bitstream/item/159254/1/TRANSF-TECN-COMPART-CONHECIM-2017.pd

Online Extraction Followed by LC-MS/MS Analysis of Lipids in Natural Samples: A Proof-of-Concept Profiling Lecithin in Seeds

Sample preparation is usually a complex and time-consuming procedure, which can directly affect the quality of the analysis. Recent efforts have been made to establish analytical methods involving minimal sample preparation, automatized and performed online with the analytical techniques. Online Extraction coupled with Liquid Chromatography–Mass Spectrometry (OLE–LC–MS) allows a fully connected extraction, separation, and analysis system. In this work, the lecithin profile was investigated in commercial sunflower, almonds, peanuts, and pistachio seeds to demonstrate that the concept of extraction, followed by the online analysis of the extract, could be applied to analyze this class of analytes in such complex solid matrices without a prior off-line solvent extraction step. The extraction phase gradient method was optimized. Two different analytical columns were explored, one being a conventional C18 (50 × 2.1 mm, 1.7 µm SPP) and the other a novel self-packed SIGO-C18ec (100 × 0.5, 5 µm FPP), which resulted in better separation. The analysis repeatability was investigated, and suggestions to improve it were pointed out. A characteristic ion with a m/z of 184, related to lysophosphatidylcholine structure, was used to identify the lecithin compounds. The temperature effect on the chromatograms was also explored. In short, it was found that the OLE–LC–MS approach is suitable for the analysis of lecithin compounds in seeds, being a promising alternative for lipidomics approaches in the near future

O diálogo necessário entre extensão rural e Agroecologia

The article assumes that rural holds specifics with which it can work other possibilities besides oversizing technology as the only basis for the environmental, social, political and economic development. There is not only one rural society, but rural societies, with their productive specificities linked to the forces of nature and socio-cultural. The approachis focused on the characterization of a new rural as it presupposes the emergence of specific and endogenous forces leading to a global insertion adapted to the local soil and climate needs and socio-economics. The rural extension needs to shape up and get flexibility in the construction process of sustainable development. However, the understanding of sustainability expressed possibilities of retaining aspects geared only to environmental preservation. When considering a new rural with endogenous forces that play key roles in technological advancement and extension intervention, agroecological approach is fundamental. In several plans interact and shape a framework in which it is bio and social diversity, including technological, cultural, political, economic and social aspects. Sustainability, then, implies a breaking of dependence on social actors towards a truly effective participation able to deepen the understanding of reality to a new articulation between research and extension. From this design agroecologicalextension takes on a character of social inclusion and adapted technologies, which affects decisions on public policies in agricultural sciences beyond the production and reproduction needs of the dominant sectors.O artigo parte do pressuposto que o rural detém especificidades com as quais se podem trabalhar outras possibilidades além do superdimensionamento da tecnologia enquanto único embasamento para o desenvolvimento ambiental, social, político e econômico. Não há uma sociedade rural, mas sim sociedades rurais, com suas especificidades produtivas, ligadas às forças da natureza e sócio-culturais. O enfoque está voltado para a caracterização de um novo rural em que se pressupõe a emergência de forças específicas e endógenas que conduza a uma inserção global adaptada às necessidades edafoclimáticas e sócioeconômicas locais. A extensão em ciências agrárias necessita moldar-se e adquirir flexibilidade no processo de construção de projetos de desenvolvimento sustentável. No entanto, o entendimento atual da sustentabilidade expressa possibilidades de reter aspectos voltados apenas à preservação ambiental. Ao se pensar um novo rural com forças endógenas que desempenham papéis fundamentais no avanço tecnológico e na intervenção extensionista, é fundamental uma abordagem agroecológica. Nesta, vários planos interagem e conformam um quadro em que cabe a bio e a sociodiversidade, entre eles aspectos tecnológicos, culturais, políticos, econômicos e sociais. A sustentabilidade, então, implica num rompimento da dependência dos atores sociais na direção de uma participação realmente eficaz, capaz de aprofundar o entendimento da realidade a uma nova articulação entre investigação e extensão. A partir desse delineamento, a extensão agroecológica adquire um caráter de inclusão social e de tecnologias adaptadas, repercutindo nas decisões relativas às políticas públicas em ciências agrárias que ultrapassem as necessidades de produção e reprodução dos setores dominantes

Influence of the Nd:YAG Laser Pulse Duration on the Temperature of Primary Enamel

The aim of this study is to evaluate the temperature change on specimens of primary enamel irradiated with different pulse duration of Nd:YAG laser. Fifteen sound primary molars were sectioned mesiodistally, resulting in 30 specimens (3.5 × 3.5 × 2.0 mm). Two small holes were made on the dentin surface in which K-type thermocouples were installed to evaluate thermal changes. Specimens were randomly assigned in 3 groups (n=10): A = EL (extra long pulse, 10.000 μs), B = LP (long pulse, 700 μs), and C = SP (short pulse, 350 μs). Nd:YAG laser (λ = 1.064 μm) was applied at contact mode (10 Hz, 0.8 W, 80 mJ) and energy density of 0.637 mJ/mm2. Analysis of variance (ANOVA) was performed for the statistical analysis (P=0.46). Nd:YAG laser pulse duration provided no difference on the temperature changes on primary enamel, in which the following means were observed: A = EL (23.15°C ± 7.75), B = LP (27.33°C ± 11.32), and C = SP (26.91°C ± 12.85). It can be concluded that the duration of the laser pulse Nd:YAG increased the temperature of the primary enamel but was not influenced by different pulse durations used in the irradiation

The impact of Er:YAG laser enamel conditioning on the microleakage of a new hydrophilic sealant — UltraSeal XT® hydro™

UltraSeal XT® hydro™ is a new hydrophilic, light-cured, methacrylate-based pit and fissure sealant which has been developed by Ultradent Products, USA. The sealant is highly filled with a 53 wt.% mixture of inorganic particles which confer both thixotropy and radiopacity. The principal purpose of this study was to investigate the microleakage of UltraSeal XT® hydro™ as a function of different enamel etching techniques. The occlusal surfaces of sound, extracted human molars were either acid etched, Er:YAG laser irradiated or successively laser irradiated and acid etched. UltraSeal XT® hydro™ was applied to each group of teeth (n=10) which were subjected to a thermocycling process consisting of 2500 cycles between 5 and 50°C with a dwell time of 30s. Microleakage assessments were then carried out using 0.5 % fuchsin dye and optical microscopy. The microleakage score data were analysed using the Kruskal-Wallis, Mann–Whitney U test with Bonferroni adjustment. No significant differences in microleakage were noted between the individually acid etched and laser-irradiated groups (p>0.05); however, teeth treated with a combination of laser irradiation and acid etching demonstrated significantly lower microleakage scores (p<0.001). Electron microscopy with energy-dispersive X-ray analysis revealed that the mineral filler component of UltraSeal XT® hydro™ essentially comprises micrometre-sized particles of inorganic silicon-, aluminium- and barium-bearing phases. Laser etching increases the roughness of the enamel surface which causes a concentrated zoning of the filler particles at the enamel-sealant interface

Effect of Er:YAG laser enamel conditioning and moisture on the microleakage of a hydrophilic sealant

For a given sealant, successful pit and fissure sealing is principally governed by the enamel conditioning technique and the presence of moisture contamination. A new generation of hydrophilic resin sealants is reported to tolerate moisture. This study investigates the impact of Er:YAG laser pre-conditioning and moisture contamination on the microleakage of a recent hydrophilic sealant. Occlusal surfaces of extracted human molars were either acid etched (n = 30), or successively lased and acid etched (n = 30). Ten teeth from each group were either air-dried, water-contaminated, or saliva-contaminated prior to sealing with UltraSeal XT® hydro™. Samples were inspected for penetration of fuchsin dye following 3000 thermocycles between 5 and 50 °C, and the enamel–sealant interfaces were observed by scanning electron microscopy (SEM). Significant differences in microleakage were evaluated using the Mann–Whitney U test with Bonferroni adjustment (p = 0.05). Laser pre-conditioning significantly reduced dye penetration irrespective of whether the enamel surface was moist or dry. Microleakageof water-contaminated acid etched teeth was significantly greater than that of their air-dried or saliva-contaminated counterparts. SEM analysis demonstrated good adaptation in all groups with the exception of water-contaminated acid etched teeth which exhibited relatively wide gaps. In conclusion, this hydrophilic sealant tolerates the presence of saliva, although water was found to impair its sealing ability. Laser pre-conditioning significantly decreases microleakage in all cases

Characterisation and microleakage of a new hydrophilic fissure sealant – UltraSeal XT® hydro™

Objectives: The new hydrophilic fissure sealant, UltraSeal XT® hydro™ (Ultradent Products, USA), was characterised and its in vitro resistance to microleakage after placement on conventionally acid etched and sequentially lased and acid etched molars was investigated. Materials and Methods: The sealant was characterised by Fourier transform infra-red spectroscopy, (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and Vickers indentation test. Occlusal surfaces of extracted human molars were either conventionally acid etched (n = 10), or sequentially acid etched and laser irradiated (n = 10). UltraSeal XT® hydro™ was applied to both groups of teeth which were then subjected to 2500 thermocycles between 5 and 55 °C prior to microleakage assessment by fuchsin dye penetration. Results: UltraSeal XT® hydro™ is an acrylate-based sealant which achieved a degree of conversion of 50.6 ± 2.2% and a Vickers microhardness of 24.2 ± 1.5 under standard light curing (1000 mWcm-2 for 20 s). Fluoride ion release was negligible within a 14-day period. SEM and EDX analyses indicated that the sealant comprises irregular sub-micron and nano-sized silicon-, barium- and aluminium-bearing filler phases embedded within a ductile matrix. Laser preconditioning was found to significantly reduce microleakage (Mann-Whitney U test, p < 0.001). The lased teeth presented enhanced surface roughness on a 50 to 100 μm scale which caused the segregation and concentration of the filler particles at the enamel-sealant interface. Conclusion: Laser preconditioning significantly decreased microleakage and increased enamel surface roughness which caused zoning of the filler particles at the enamel-sealant interface