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The natural antimicrobial properties of essential oils (EOs) have contributed to the battle against multidrug-resistant microorganisms by providing new ways to develop more effective antibiotic agents. In this study, we investigated the chemical composition of Ocotea diospyrifolia essential oil (OdOE) and its antimicrobial properties combined with amikacin (AMK). Through gas chromatography-mass spectrometry (GCMS) analysis, the primary constituents of OdOE were identified as α-bisabolol (45.8 %), ß-bisabolene (9.4 %), γ-elemene (7.6 %), (Z)- ß-farnesene (5.2 %), spathulenol (3.5 %), (Z)-caryophyllene (3.3 %), and (E)-caryophyllene (3.1 %). In vitro assessments showed that the combined administration of OdOE and AMK exerted a synergistic antibacterial effect on the multidrug-resistant K. pneumoniae strain. This synergistic effect demonstrated bacteriostatic action. OdEO combined with amikacin showed protein extravasation within 2 h of treatment, leading to bacterial death, which was determined by a reduction in viable cell count. The effective concentrations showed hemocompatibility. In vivo assessments using Caenorhabditis elegans as a model showed the survival of 85 % of infected nematodes. Therefore, the combination OdEO combined with amikacin exhibited antimicrobial activity against a multidrug-resistant K. pneumoniae strain. Thus, OdOE is a promising agent that may be considered for development of antimicrobial treatment.
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Amicacina , Antibacterianos , Farmacorresistência Bacteriana Múltipla , Sinergismo Farmacológico , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Óleos Voláteis , Amicacina/farmacologia , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Animais , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Antibacterianos/farmacologia , Klebsiella pneumoniae/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Caenorhabditis elegans/efeitos dos fármacos , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Sesquiterpenos Monocíclicos/farmacologia , Sesquiterpenos Policíclicos/farmacologia , Sesquiterpenos Policíclicos/química , Sesquiterpenos/farmacologiaRESUMO
AIM: Osseointegration of titanium implants is predictable, but can be improved via surface functionalization. MATERIALS AND METHODS: One hundred and twenty implants were installed in parietal bone of 12 domestic pigs and left to heal for 1 or 3 months. Five groups were defined according surface treatments: immersion in water (H2 O), 10% polyphosphoric acid (PPA10), 1% phosphorylated pullulan (PPL1), 10% phosphorylated pullulan (PPL10) or 10% phosphorylated pullulan + 1 µg bone morphogenetic protein-2 (PPL10 BMP). As primary outcome, implant osseointegration was evaluated by quantitative histology, namely peri-implant bone formation (B/T in %) and bone-to-implant contact (BIC in %) for each healing period. The Wilcoxon signed-rank test and Mann-Whitney U-test with α = 0.05 were performed. RESULTS: PPL10 and PPA10 groups showed significantly higher B/T and BIC results than the control (H2 O) group at 1-month (p < .05). No significant difference was found between PPL1 and H2 O or between PPL10 BMP and H2 O, irrespective of healing time (1 or 3 months) or investigated parameter (B/T and BIC; p > .05). After 3 months, no experimental group showed a significant difference compared to the control group (H2 O) for both investigated parameters (B/T and BIC; p > .05). CONCLUSION: Functionalizing titanium implants with inorganic or organic phosphate-containing polymers at 10 wt% concentration may stimulate peri-implant bone formation and implant osseointegration at early healing times.
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Materiais Revestidos Biocompatíveis/farmacologia , Implantação Dentária Endóssea/métodos , Implantes Dentários , Osseointegração/fisiologia , Titânio/farmacologia , Animais , Proteína Morfogenética Óssea 2/farmacologia , Interface Osso-Implante , Planejamento de Prótese Dentária , Glucanos/farmacologia , Implantes Experimentais , Modelos Animais , Ácidos Fosfóricos/farmacologia , Polímeros/farmacologia , Crânio/cirurgia , Propriedades de Superfície , Retalhos Cirúrgicos , SuínosRESUMO
There is strong evidence of shared acoustic profiles common to the expression of emotions in music and speech, yet relatively limited understanding of the specific psychoacoustic features involved. This study combined a controlled experiment and computational modelling to investigate the perceptual codes associated with the expression of emotion in the acoustic domain. The empirical stage of the study provided continuous human ratings of emotions perceived in excerpts of film music and natural speech samples. The computational stage created a computer model that retrieves the relevant information from the acoustic stimuli and makes predictions about the emotional expressiveness of speech and music close to the responses of human subjects. We show that a significant part of the listeners' second-by-second reported emotions to music and speech prosody can be predicted from a set of seven psychoacoustic features: loudness, tempo/speech rate, melody/prosody contour, spectral centroid, spectral flux, sharpness, and roughness. The implications of these results are discussed in the context of cross-modal similarities in the communication of emotion in the acoustic domain.
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Sinais (Psicologia) , Emoções , Música/psicologia , Psicoacústica , Fala , Estimulação Acústica , Adolescente , Adulto , Percepção Auditiva , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Psicológicos , Redes Neurais de ComputaçãoRESUMO
Music composition is a complex field that is difficult to automate because the computational definition of what is good or aesthetically pleasing is vague and subjective. Many neural network-based methods have been applied in the past, but they lack consistency and in most cases, their outputs fail to impress. The most common issues include excessive repetition and a lack of style and structure, which are hallmarks of artificial compositions. In this project, we build on a model created by Magenta-the RL Tuner-extending it to emulate a specific musical genre-the Galician Xota. To do this, we design a new rule-set containing rules that the composition should follow to adhere to this style. We then implement them using reward functions, which are used to train the Deep Q Network that will be used to generate the pieces. After extensive experimentation, we achieve an implementation of our rule-set that effectively enforces each rule on the generated compositions, and outline a solid research methodology for future researchers looking to use this architecture. Finally, we propose some promising future work regarding further applications for this model and improvements to the experimental procedure.
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The advent of "Adhesive Dentistry" has simplified the guidelines for cavity preparation enormously. The design and extent of the current preparations are basically defined by the extent and shape of the caries lesion, potentially slightly extended by bevelling the cavity margins in order to meet the modern concept of minimally invasive dentistry. New caries excavation techniques have been introduced, such as the use of plastic and ceramic burs, improved caries-disclosing dyes, enzymatic caries-dissolving agents, caries-selective sono/air abrasion and laser ablation. They all aim to remove or help remove caries-infected tissue as selectively as possible, while being minimally invasive through maximum preservation of caries-affected tissue. Each technique entails a specific caries-removal endpoint and produces residual dentin substrates of different natures and thus different receptiveness for adhesive procedures. This paper reviews the newest developments in caries excavation techniques and their effect on the remaining dentin tissue with regard to its bonding receptiveness.
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Colagem Dentária , Cárie Dentária/terapia , Preparo da Cavidade Dentária/instrumentação , Preparo da Cavidade Dentária/métodos , Dentina/patologia , Abrasão Dental por Ar , Corantes , Tratamento Dentário Restaurador sem Trauma/instrumentação , Tratamento Dentário Restaurador sem Trauma/métodos , Cárie Dentária/patologia , Testes de Atividade de Cárie Dentária , Análise do Estresse Dentário , Humanos , Lasers de Estado Sólido/uso terapêuticoRESUMO
Objective: To investigate the effects of sound-based interventions (SBIs) on biomechanical parameters in stroke patients. Methods: PubMed/Medline, Web of Science, the Physiotherapy Evidence Database (PEDro), and the Cochrane Library were searched until September 2019. Studies examining the effect of SBIs on kinematic, kinetic, and electromyographic outcome measures were included. Two independent reviewers performed the screening, and data extraction and risk-of-bias assessment were conducted with the PEDro and Newcastle-Ottawa scale. Disagreements were resolved by a third independent reviewer. Results: Of the 858 studies obtained from all databases, 12 studies and 240 participants met the inclusion and exclusion criteria. Six studies investigated the effect of SBI on upper limb motor tasks, while six examined walking. Concerning quality assessment (Newcastle-Ottawa Quality Assessment Scale and PEDro), the nine cross-sectional studies had a median score of seven, while the randomized controlled trials had a median score of five (fair to good quality). In relation to upper limb motor tasks, only one study found improvements in cortical reorganization and increased central excitability and motor control during reaching after SBI (results of the other five studies were too diverse and lacked quality to substantiate their findings). In relation to walking, results were clearer: SBI led to improvements in knee flexion and gastrocnemius muscle activity. Conclusion: Despite of the heterogeneity of the included studies, evidence was found demonstrating that SBI can induce biomechanical changes in motor behavior during walking in stroke patients. No conclusions could be formulated regarding reaching tasks. Additionally, directions for future research for understanding the underlying mechanism of the clinical improvements after SBI are: (1) using actual music pieces instead of rhythmic sound sequences and (2) examining sub-acute stroke rather than chronic stroke patients.
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BACKGROUND: As music listening is able to induce self-perceived and physiological signs of relaxation, it might be an interesting tool to induce muscle relaxation in patients with hypertonia. To this date effective non-pharmacological rehabilitation strategies to treat hypertonia in neurologically impaired patients are lacking. Therefore the aim is to investigate the effectiveness of music listening on muscle activity and relaxation. METHODOLOGY: The search strategy was performed by the PRISMA guidelines and registered in the PROSPERO database (no. 42019128511). Seven databases were systematically searched until March 2019. Six of the 1,684 studies met the eligibility criteria and were included in this review. Risk of bias was assessed by the PEDro scale. In total 171 patients with a variety of neurological conditions were included assessing hypertonia with both clinicall and biomechanical measures. RESULTS: The analysis showed that there was a large treatment effect of music listening on muscle performance (SMD 0.96, 95% CI [0.29-1.63], I 2 = 10%, Z = 2.82, p = 0.005). Music can be used as either background music during rehabilitation (dual-task) or during rest (single-task) and musical preferences seem to play a major role in the observed treatment effect. CONCLUSIONS: Although music listening is able to induce muscle relaxation, several gaps in the available literature were acknowledged. Future research is in need of an accurate and objective assessment of hypertonia.
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UNLABELLED: The current trend toward minimal-invasive dentistry has introduced innovative techniques for cavity preparation. Chemical vapor deposition (CVD) and laser-irradiation technology have been employed as an alternative to the common use of regular burs in high-speed turbines. OBJECTIVES: The purpose of this study was to assess the influence of alternative techniques for cavity preparation on the bonding effectiveness of different adhesives to dentin, and to evaluate the morphological characteristics of dentin prepared with those techniques. METHODS: One etch&rinse adhesive (OptiBond FL, Kerr) and three self-etch systems (Adper Prompt L-Pop, 3M ESPE; Clearfil SE Bond, Kuraray; Clearfil S3 Bond, Kuraray) were applied on dentin prepared with a regular bur in a turbine, with a CVD bur in a turbine, with a CVD tip in ultrasound and with an Er,Cr:YSGG laser. The micro-tensile bond strength (microTBS) was determined after storage in water for 24h at 37 degrees C, and morphological evaluation was performed by means of field-emission-gun scanning electron microscopy (Feg-SEM). RESULTS: Feg-SEM evaluation revealed different morphological features on the dentin surface after the usage of both the conventional and alternative techniques for cavity preparation, more specifically regarding smear-layer thickness and surface roughness. CVD bur-cut, CVD ultra-sonoabraded and laser-irradiated dentin resulted in lower microTBSs than conventionally bur-cut dentin, irrespective of the adhesive employed. SIGNIFICANCE: The techniques, such as CVD diamond-bur cutting, CVD diamond ultra-sonoabrasion and laser-irradiation, used for cavity preparation may affect the bonding effectiveness of adhesives to dentin, irrespective of their acidity or approach.
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Colagem Dentária , Preparo da Cavidade Dentária/métodos , Cimentos de Resina , Abrasão Dental por Ar , Análise do Estresse Dentário , Dentina/anatomia & histologia , Gases , Humanos , Lasers de Estado Sólido , Microscopia Eletrônica de Varredura/métodos , Dente Serotino , Resistência à Tração , UltrassomRESUMO
OBJECTIVES: To evaluate the micro-tensile bond strength (mu TBS) of a control etch-and-rinse and three self-etch (strong, mild, ultra-mild) adhesive systems to dentin prepared with three different grit size of diamond burs. METHODS: Dentin surfaces were created from mid-coronal sound dentin in extracted, human third molars. The teeth were ground with high-speed medium grit (100 microm), fine grit (30 microm), or extra-fine grit (15 microm) diamond bur. Resin composite (Z100) was bonded to the surfaces using Optibond FL, Adper Prompt L-Pop, Clearfil SE Bond, or Clearfil S3 Bond. Rectangular micro-specimens were prepared using the slow-speed diamond saw and tested in tensile to determine the mu TBS. Failure analysis was performed using a stereo-microscope and Fe-SEM. Data were analyzed by two-way analysis of variance and Tukey's HSD test (p<0.05). RESULTS: The etch-and-rinse adhesive yielded high micro-tensile values (58-69 MPa), irrespective of the diamond burs used. The bond strength values were comparable for Adper Prompt L-Pop and Clearfil SE Bond irrespective of the burs used. The mu TBS values were significantly higher as the particle size of diamond burs is smaller for Clearfil S3 Bond. Most failures were recorded as interfacial failure when the fine and extra-fine diamond burs were used. SIGNIFICANCE: Overall, different grit-sized diamond burs did not affect the mechanical properties of the interface, except for the ultra-mild one step self-etch adhesive. This adhesive performed significantly better when a smaller grit size was used to prepare dentin surface.
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Colagem Dentária , Corrosão Dentária/instrumentação , Adesivos Dentinários/química , Dentina/ultraestrutura , Diamante/química , Preparo do Dente/instrumentação , Resinas Compostas/química , Equipamentos Odontológicos de Alta Rotação , Humanos , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Cimentos de Resina/química , Dióxido de Silício/química , Camada de Esfregaço , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração , Zircônio/químicaRESUMO
OBJECTIVES: Describe stress distribution and compare stress concentration factor (K(t)) for homogeneous micro-specimens with different notch geometries and stick-shaped homogeneous and bimaterial specimens by means of finite element (FE) analysis. METHODS: Axisymmetric models were created for homogeneous specimens with different notches and for stick-shaped homogeneous and bimaterial specimens. FE mesh was refined at areas of expected stress concentration and boundary conditions included an applied tensile stress in the axial direction. Linear elastic analysis was used. RESULTS: For hourglass homogeneous specimens, K(t) equaled 1.32 and 1.12 for a notch radius of 0.6mm and 3.3mm, respectively. A non-uniform axial (sigma(zz)) stress distribution was found in the notch cross-section, with values at the outer edge being 78% and 25% larger than at the center. In addition, a triaxial stress state was generated. Stick-shaped and dumbbell homogeneous specimens presented K(t)=1 and a uniform, uniaxial stress distribution along the entire cross-section. Shear stresses were zero for all homogeneous specimens. When an adhesive interface was added to the stick-shaped specimen, an area of localized axial stress concentration (K(t)=1.55) was detected at the bimaterial joint near the outer edge. Normal stresses sigma(rr) and sigma(thetatheta) and shear stress tau(zr) were also non-zero at the free-edge. CONCLUSIONS: Dumbbell or stick-shaped specimens are favored for muTBS testing, as they do not present stress concentrations due to geometry. However, dissimilar mechanical properties of joint components will lead to stress concentrations and non-uniform multi-axial stresses, although to a lesser extent.
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Colagem Dentária , Análise do Estresse Dentário/métodos , Análise de Elementos Finitos , Estresse Mecânico , Resistência à Tração , Teste de Materiais , Modelos AnatômicosRESUMO
PURPOSE: To evaluate how six different test parameters (TP) of the microtensile bond strength (microTBS) methodology influence the test outcome. MATERIALS AND METHODS: The microtensile bond strength of adhesives bonded to dentin was measured, and the resultant failure patterns and stress-time graphs were analyzed, varying the microTBS specimen-fixation mode (TP1), the microspecimen geometry (TP2), the microspecimen bond surface area (TP3), the remaining dentin thickness of the microspecimens (TP4), the procedure employed to glue the microspecimen to the microTBS jig (TP5), and the microTBS crosshead speed (TP6). RESULTS: The orientation of the microspecimens to the actual interface primarily influenced the resultant microTBS value and the eventual failure pattern. A notched jig consistently yielded significantly higher mciroTBS values than samples fixed onto a flat jig or following a "top-bottom" design (TP1). A higher bond strength, a lower standard deviation/coefficient of variation, a failure closer to the interface, and a more representative number of specimens per tooth were obtained for nontrimmed, square microspecimens (TP2). The most reproducible results were obtained using square specimens of 1 mm2 (TP3), which could also be most easily prepared. The remaining dentin thickness (TP4) was an influential factor as well, whereas the microspecimen gluing protocol (TP5) and the crosshead speed (TP6) appeared less influential. CONCLUSION: As several test parameters significantly influenced the microTBS outcome, sufficient attention should be paid to these methodology variables with regard to the microTBS-test reliability and reproducibility.
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Colagem Dentária , Adesivos Dentinários/química , Dentina/ultraestrutura , Resinas Compostas/química , Humanos , Teste de Materiais/instrumentação , Teste de Materiais/métodos , Microscopia Eletrônica de Varredura , Cimentos de Resina/química , Dióxido de Silício/química , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração , Fatores de Tempo , Zircônio/químicaRESUMO
The current trend towards minimum-intervention dentistry has introduced laser technology as an alternative technique for cavity preparation. This study assessed the null hypothesis that enamel prepared either by Er,Cr:YSGG laser or conventional diamond bur is equally receptive to adhesive procedures. The buccal and lingual surfaces of 35 sound human molars were prepared with Er,Cr:YSGG laser or a medium-grit diamond bur. One etch&rinse (OptiBond FL) and three self-etch adhesives (Adper Prompt L-Pop, Clearfil SE Bond and Clearfil S3 Bond) were applied on laser-irradiated and bur-cut enamel, followed by the application of a 5-6 mm build-up of Z100. The micro-tensile bond strength (microTBS) was determined after 24 hours of storage in water at 37 degrees C. Prepared enamel surfaces and failure patterns were evaluated using a stereomicroscope and a field-emission-gun scanning electron microscope (Feg-SEM). The pTBS to laser-irradiated enamel was significantly lower than to bur-cut enamel (p<0.05), with the exception of Clearfil S3 Bond, which bonded equally effectively to both substrates. The latter presented the highest microTBS on laser-irradiated enamel, though it was not statistically different from the microTBS of OptiBond FL. SEM analysis revealed significant morphological alterations of the laser-irradiated enamel surface, such as areas of melted and recrystalized hydroxyapatite and deep extensive micro-cracks. In conclusion, the bonding effectiveness of adhesives to laser-irradiated enamel depends not only on the structural substrate alterations induced by the laser, but also on the characteristics of the adhesive employed.
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Colagem Dentária , Cimentos Dentários/química , Esmalte Dentário/ultraestrutura , Terapia a Laser , Lasers de Estado Sólido/uso terapêutico , Resinas Compostas/química , Cristalografia , Preparo da Cavidade Dentária/instrumentação , Esmalte Dentário/efeitos da radiação , Restauração Dentária Permanente , Adesivos Dentinários/química , Diamante/química , Durapatita/química , Durapatita/efeitos da radiação , Humanos , Microscopia Eletrônica de Varredura , Cimentos de Resina/química , Dióxido de Silício/química , Estresse Mecânico , Propriedades de Superfície , Temperatura , Resistência à Tração , Fatores de Tempo , Água/química , Zircônio/químicaRESUMO
[This corrects the article DOI: 10.1371/journal.pone.0179289.].
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Comparison of emotion perception in music and prosody has the potential to contribute to an understanding of their speculated shared evolutionary origin. Previous research suggests shared sensitivity to and processing of music and speech, but less is known about how emotion perception in the auditory domain might be influenced by individual differences. Personality, emotional intelligence, gender, musical training and age exert some influence on discrete, summative judgments of perceived emotion in music and speech stimuli. However, music and speech are temporal phenomena, and little is known about whether individual differences influence moment-by-moment perception of emotion in these domains. A behavioral study collected two main types of data: continuous ratings of perceived emotion while listening to extracts of music and speech, using a computer interface which modeled emotion on two dimensions (arousal and valence), and demographic information including measures of personality (TIPI) and emotional intelligence (TEIQue-SF). Functional analysis of variance on the time series data revealed a small number of statistically significant differences associated with Emotional Stability, Agreeableness, musical training and age. The results indicate that individual differences exert limited influence on continuous judgments of dynamic, naturalistic expressions. We suggest that this reflects a reliance on acoustic cues to emotion in moment-by-moment judgments of perceived emotions and is further evidence of the shared sensitivity to and processing of music and speech.
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In the present study, we applied Machine Learning (ML) methods to identify psychobiological markers of cognitive processes involved in the process of emotion elicitation as postulated by the Component Process Model (CPM). In particular, we focused on the automatic detection of five appraisal checks-novelty, intrinsic pleasantness, goal conduciveness, control, and power-in electroencephalography (EEG) and facial electromyography (EMG) signals. We also evaluated the effects on classification accuracy of averaging the raw physiological signals over different numbers of trials, and whether the use of minimal sets of EEG channels localized over specific scalp regions of interest are sufficient to discriminate between appraisal checks. We demonstrated the effectiveness of our approach on two data sets obtained from previous studies. Our results show that novelty and power appraisal checks can be consistently detected in EEG signals above chance level (binary tasks). For novelty, the best classification performance in terms of accuracy was achieved using features extracted from the whole scalp, and by averaging across 20 individual trials in the same experimental condition (UAR = 83.5 ± 4.2; N = 25). For power, the best performance was obtained by using the signals from four pre-selected EEG channels averaged across all trials available for each participant (UAR = 70.6 ± 5.3; N = 24). Together, our results indicate that accurate classification can be achieved with a relatively small number of trials and channels, but that averaging across a larger number of individual trials is beneficial for the classification for both appraisal checks. We were not able to detect any evidence of the appraisal checks under study in the EMG data. The proposed methodology is a promising tool for the study of the psychophysiological mechanisms underlying emotional episodes, and their application to the development of computerized tools (e.g., Brain-Computer Interface) for the study of cognitive processes involved in emotions.
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Eletroencefalografia/métodos , Eletromiografia/métodos , Emoções , Face/fisiologia , Encéfalo/fisiologia , Humanos , Modelos Teóricos , Máquina de Vetores de SuporteRESUMO
Dental adhesives are designed to bond composite resins to enamel and dentin. Their chemical formulation determines to a large extent their adhesive performance in clinic. Irrespective of the number of bottles, an adhesive system typically contains resin monomers, curing initiators, inhibitors or stabilizers, solvents and sometimes inorganic filler. Each one of these components has a specific function. The aim of this article is to systematically review the ingredients commonly used in current dental adhesives as well as the properties of these ingredients. This paper includes an extensive table with the chemical formulation of contemporary dental adhesives.
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Colagem Dentária , Cimentos Dentários/química , Adesividade , Dureza , Estresse MecânicoRESUMO
OBJECTIVES: To determine the effect of grinding on the bonding effectiveness of a self-etch and an etch-and-rinse adhesive to fluorosed enamel. METHODS: The teeth were classified using the Thylstrup and Fejerskov index (TFI). Fluorosed teeth (TFI=5) obtained from Isparta (Turkey) and control teeth (TFI=0) obtained from Leuven (Belgium) were used. Using a depth-marking diamond bur, 0.3mm of enamel was removed from mid-buccal and mid-palatal/lingual surfaces of the teeth, whereas the area adjacent to the ground area was left unprepared. A two-step self-etch (Clearfil Protect Bond, Kuraray) and a three-step etch-and-rinse adhesive (Optibond FL, Kerr) were used to bond the resin composite to the ground and unground enamel. Rectangular micro-specimens were prepared using the slow-speed diamond saw and tested in tensile to determine the micro-tensile bond strength (microTBS). RESULTS: The microTBS to unground fluorosed enamel was significantly lower than to ground fluorosed enamel for Clearfil Protect Bond (15.8+/-15.2 and 45.0+/-12.4MPa, p<0.0001) and for Optibond FL (35.5+/-21.4 and 50.5+/-12.3MPa, p<0.05), respectively. In control teeth, Clearfil Protect Bond bonded better to ground enamel (p<0.01), whereas OptiBond FL exhibited a similar bonding effectiveness to ground and unground enamel (p=0.0634). SIGNIFICANCE: Preparation of enamel improved the resin-enamel bond strength in fluorosed teeth. The bonding effectiveness to unground enamel was lower in fluorosed teeth than in control teeth for the self-etch adhesive tested.
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Colagem Dentária/métodos , Esmalte Dentário/química , Fluorose Dentária , Adesivos/química , Análise de Variância , Esmalte Dentário/anormalidades , Corrosão Dentária/métodos , Humanos , Resistência à TraçãoRESUMO
PURPOSE: To determine the effect of thorough air drying on the static and dynamic bonding effectiveness of a HEMA-free all-in-one adhesive bonded to Class-1 cavity-bottom dentin. MATERIALS AND METHODS: G-Bond (GC, Japan) was applied to standard occlusal Class I cavities following either a gentle (1 bar) or strong (4 bar) air-drying technique. After restoring the cavity using a composite resin (Gradia Anterior, GC), microspecimens were prepared that were loaded until failure or inserted in a microrotary fatigue testing device. RESULTS: Strong air drying had no effect on the static (39.1 vs. 38.4 MPa) or the dynamic (19.0 vs. 18.6 MPa) strength of the interface complex. CONCLUSION: Strong air drying did not improve the static or the dynamic bonding effectiveness, although a very thorough (4 bar) and long air-drying procedure was employed. SEM analysis revealed that even when the adhesive was strongly air dried, droplets originating from phase separations could still be observed, albeit to a reduced extent. Ineffective drying and pooling of the adhesive in a narrow cavity diminished the effect of strong air drying of the all-in-one adhesive.
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Ar , Colagem Dentária/métodos , Adesivos Dentinários/química , Metacrilatos/química , Humanos , Modelos Logísticos , Resistência à TraçãoRESUMO
The aim of this study was to investigate in how far the way the specimen is fixed to the testing device influences the micro-tensile bond strength of adhesives to dentin. Compared to a flat jig, a notched jig enables the specimen to be aligned easier and more accurately perpendicular to the interface, thereby concentrating better the tensile stress at the actual interface. A notched jig yielded a significantly higher bond strength and the graphs showed more uniform fracture curves. On the other hand, fixation of the specimen at their top and bottom guarantees a perfect perpendicular fixation to the interface, following the specimen's length-axis. The stress-time graphs revealed a completely different stress-distribution pattern. A failure closer to the dentin-composite interface was more often seen and the coefficient of variance was the lowest. Therefore, this completely newly designed top-bottom set-up produced the most reliable bond strength data.
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Colagem Dentária , Análise do Estresse Dentário/métodos , Adesivos Dentinários , Cimentos de Resina , Dentina , Teste de Materiais , Metacrilatos , Manejo de Espécimes/métodos , Resistência à TraçãoRESUMO
Music and speech exhibit striking similarities in the communication of emotions in the acoustic domain, in such a way that the communication of specific emotions is achieved, at least to a certain extent, by means of shared acoustic patterns. From an Affective Sciences points of view, determining the degree of overlap between both domains is fundamental to understand the shared mechanisms underlying such phenomenon. From a Machine learning perspective, the overlap between acoustic codes for emotional expression in music and speech opens new possibilities to enlarge the amount of data available to develop music and speech emotion recognition systems. In this article, we investigate time-continuous predictions of emotion (Arousal and Valence) in music and speech, and the Transfer Learning between these domains. We establish a comparative framework including intra- (i.e., models trained and tested on the same modality, either music or speech) and cross-domain experiments (i.e., models trained in one modality and tested on the other). In the cross-domain context, we evaluated two strategies-the direct transfer between domains, and the contribution of Transfer Learning techniques (feature-representation-transfer based on Denoising Auto Encoders) for reducing the gap in the feature space distributions. Our results demonstrate an excellent cross-domain generalisation performance with and without feature representation transfer in both directions. In the case of music, cross-domain approaches outperformed intra-domain models for Valence estimation, whereas for Speech intra-domain models achieve the best performance. This is the first demonstration of shared acoustic codes for emotional expression in music and speech in the time-continuous domain.