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Microorganism biomass is a sustainable and innovative source of biopolymers, such as proteins and polysaccharides, that is suitable for the development of biodegradable films. The aim of this research was to evaluate the synthesis, morphology, rheology, and morphological and mechanical properties on the production of edible biofilms based on water kefir grains, and compare them with edible films based on thermoplastic compounds from starch (TPS) obtained from taro (Colocasia esculenta) and cassava (Manihot esculenta). Edible biofilms were prepared in solution with 30% wt/wt glycerol relative to starch mass and kefir grain biofilms using the casting method. A stationary rheological analysis was performed on the film-forming suspensions of kefir, taro starch, and cassava starch. Once the films were obtained, a physicochemical and morphological characterization was carried out. Results of the characterization showed the following main aspects: The results indicated an increase in biomass production using muscovado and pineapple peel. The film-forming suspensions had a dilating behavior; however, the results obtained not only show the viscoelastic behavior but also the elastic limit (σ0), which varied from 0.077 to 0.059 Pa for suspensions of water kefir grains and from 0.077 to 0.072 Pa for starch suspensions. These elastic limit variations can be defined as the minimum shear stress required to start the flow, and all these rheological data were adjusted to the Herschel–Bulkley model; the morphological and mechanical characterization of the films obtained showed homogeneous surfaces with transparency and without cracks; regarding the water activity, values lower than 6 were obtained, which indicates that there will be no growth of any microorganism, and the hardness data showed differences between those obtained from kefir and taro and cassava starch. The similar results of the rheological characterization in the formation of the kefir biofilm and the conventional edible starch films, in addition to the similar results in the water activity below 6 and the hardness, points to an attractive alternative capable of replacing the conventional materials with a mass production of biofilms of probiotic microorganisms. The results also revealed that water kefir grains biomass is a viable and innovative source of biodegradable materials, and these grains can be an alternative to conventional established starch materials. [ABSTRACT FROM AUTHOR]

This study assesses different thermal-physical-mechanical properties and micro structural characteristics of multilayer particleboards (outer layers made of sugarcane bagasse and inner layer made of sugarcane bagasse and Amazonia vegetable fibres—curaua and jute). Initially, anatomical and physical-chemical properties from these natural fibres were characterized individually in order to evaluate their potential for use in the production of particleboard. The bulk density of the panels was designed to be 550 kg m−3, and was checked by X-ray. Physical and mechanical properties were evaluated following the ABNT NBR 14810:2013 (2013) Brazilian Standards recommendations. The thermal conductivity was determined by adapting the methodology established by ISO 8301:1999. Results indicate that the multilayer boards present higher superficial density, compared to the inner layers. Mechanical property values of the particleboards with vegetable fibres were higher than the panels using only sugarcane bagasse for the corresponding densities. Moreover, the thermal conductivity of the multilayer boards was similar, indicating that the inclusion of vegetable fibres did not affect this property. The X-ray micro-tomography analyses (microCT) indicated higher porosity in the internal layer. Considering durability tests, the particleboards with vegetable fibres presented lower mechanical properties after aging test. [ABSTRACT FROM AUTHOR]

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Co-Cr alloys are widely used in fabrication of removable partial dentures, particularly as a dental framework. The micro-movements between the framework and the teeth or some particles of food in contact with the framework can lead to wear. The present study aimed at studying the influence of the commercial mouthwashes on the corrosion and tribocorrosion behaviour of the Co−Cr dental casting alloy. Corrosion behaviour was investigated in alcohol-free and alcohol-containing Listerine® and Colgate Plax® added artificial saliva solutions at body temperature by electrochemical impedance spectroscopy and potentiodynamic polarization tests. Additionally, tribocorrosion tests, performed in selective solutions under open circuit potential, using a reciprocating ball-on-plate tribometer, were used to study the combined action of wear and corrosion. Results suggest that the presence of mouthwashes did not affect negatively the corrosion and tribocorrosion behavior of Co-Cr dental alloy. [ABSTRACT FROM AUTHOR]

This in situ study evaluated the effect of Er:YAG laser irradiation in controlling the progression of enamel erosion-like lesions. Fifty-six enamel slabs (330 KHN ± 10 %) with one fourth of the surface covered with resin composite (control area) were submitted to initial erosion-like lesion formation with citric acid. The slabs were divided into two groups: irradiated with Er:YAG laser and non-irradiated. Fourteen volunteers used an intraoral palatal appliance containing two slabs, in two phases of 5 days each. During the intraoral phase, in a crossed-over design, half of the volunteers immersed the appliance in citric acid while the other half used deionized water, both for 5 min, three times per day. Enamel wear was determined by an optical 3D profilometer. ANOVA revealed that when deionized water was used as immersion solution during the intraoral phase, lower values of wear were showed when compared with the groups that were eroded with citric acid, whether irradiated or non-irradiated with Er:YAG laser. When erosion with citric acid was performed, Er:YAG laser was not able to reduce enamel wear. Small changes on enamel surface were observed when it was irradiated with Er:YAG laser. It may be concluded that Er:YAG laser irradiation did not reduce the progression of erosive lesions on enamel submitted to in situ erosion with citric acid. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of CO2 laser irradiation and topical fluoride therapy in the control of caries progression on primary teeth enamel. 30 fragments (3×3×2 mm) from primary canines were submitted to an initial cariogenic challenge that consisted of immersion on demineralizing solution for 3 hours and remineralizing solution for 21 hours for 5 days. Fragments were randomly assigned into three groups (n=10): L: CO2 laser (λ=10.6 μm), APF: 1.23% acidulated phosphate fluoride, and C: no treatment (control). CO2 laser was applied with 0.5 W power and 0.44 J/cm2 energy density. Fluoride application was performed with 0.1 g for 1 minute. Cariogenic challenge was conducted for 5 days following protocol previously described. Subsurface Knoop microhardness was measured at 30 μm from the edge. Obtained data were subjected to analysis the variance (ANOVA) and Duncan test with significance of 5%. It was found that the L group showed greater control of deciduous enamel demineralization and were similar to those of APF group, while being statistically different from C group (P≤0.05) that showed the lowest microhardness values. It was concluded that CO2 laser can be an additional resource in caries control progression on primary teeth enamel. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The application of a variable control structure for tubular reactors, based on multiple temperature measurements, is explored. The proposed structure allows the controller to adapt to temperature error variations along the tubular reactor. Controllers can be designed from simple input-output first-order dynamical models obtained from step responses and are coupled with a dynamic law for assigning a variable weight to conventional feedback cascade control loops. The simulation results show that the variable structure based on linear proportional-integral controllers enhances the performance and robustness properties of conventional cascade schemes for controlling the outlet reactor concentration. Major advantages are shown in the face of a variety of concentration and temperature feed disturbances. [ABSTRACT FROM AUTHOR]

Background. The aim of this study was to perform a systematic review of the literature on the efficacy of antimicrobial photodynamic therapy (PDTa) on cariogenic dental biofilm. Types of Studies Reviewed. Studies in vivo, in vitro, and in situ were included. Articles that did not address PDTa, those that did not involve cariogenic biofilm, those that used microorganisms in the plankton phase, and reviews were excluded. Data extraction and quality assessments were performed independently by two raters using a scale. Results. Two hundred forty articles were retrieved; only seventeen of them met the eligibility criteria and were analyzed in the present review. Considerable variability was found regarding the methodologies and application protocols for antimicrobial PDTa. Two articles reported unfavorable results. Practical Implications. The present systematic review does not allow drawing any concrete conclusions regarding the efficacy of antimicrobial PDTa, although this method seems to be a promising option. [ABSTRACT FROM AUTHOR]

This paper studied the dynamics of civilian and military fatalities in the Iraq War during the 2003-2010 period. R/S-scaling analysis, a method to characterize fractality and memory effects in sequences, was used to estimate time variations in the correlations of daily fatalities. Together with concepts from complex social networks and systems theories, the dynamics of correlations (measured in terms of the so-called scaling Hurst exponent) provide a framework to describe the Iraq War evolution and to evaluate the effects of the major military and political events. In terms of changes in a correlations parameter, five regimes in the evolution of the war were identified. The first regime, occurring in the first months after the invasion, corresponds to a conventional confrontation. In the second regime occurred in the last months of 2004, the dynamics of civilian fatalities evolved toward uncorrelated behavior, indicating that the occurrence of daily fatalities was basically governed by random processes. This is in contrast to the dynamics of military fatalities that showed increased correlations. The second regime can be seen as the advent of a chaotic episode where the different insurgency groups acted within an erratic, poorly coordinated, manner. In the third regime that occurred in the first two 2005 quarters, correlations of civilian fatalities increased and converged into the correlations patterns of military fatalities, and this was interpreted as the surging of a well-organized, although non-centralized, insurgency structure. The fourth regime lasted from mid-2005 to the last 2007 months and showed an important correlation decrement for the military fatalities. This was related to the clash of two antagonist war structures, namely, the traditional centralized Coalition Army and a non-centralized insurgent army. Finally, the fifth regime, from mid-2007 to date, is characterized by stable fatality dynamics converging to uncorrelated behavior. It is apparent that this behavior is related to the start of the endgame to achieve stable economy and government. The concept of a scale-free network was used to describe the insurgency operations and the subsequent war and political events oriented to incorporate the former Baath Party member in the formation of a national Iraqi government. It is concluded that, given the availability of data (fatalities, economic activity, migration, etc.) in contemporary conflicts, the usage of mathematical methods and tools would provide further insights of the conflict evolution and, in this way, help to design better policies and strategies to reduce the adverse effects of violence on civilians. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 33-year-old woman with temporo-mandibular disorder in a Sydenham's chorea who was responding to acupuncture. It mentions that the patient claimed to experience improvement and decided to respond from acupuncture in a weekly basis. It is stated that the patient had been enjoying her embroidering and experienced no discomfort in the temporo-mandibular joint.