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Seeking to improve personal armor equipment by providing mobility and resistance to penetration, this research aimed to explore the potential of sustainable materials in order to assess their ability in ballistic applications. Titica vine fibers (TVFs) extracted from aerial roots of Heteropsis flexuosa from the Amazon region were incorporated at 10, 20, 30, and 40 vol% into an epoxy matrix for applications in ballistic multilayered armor systems (MASs) and stand-alone tests for personal protection against high-velocity 7.62 mm ammunition. The back-face signature (BFS) depth measured for composites with 20 and 40 vol% TVFs used as an intermediate layer in MASs was 25.6 and 32.5 mm, respectively, and below the maximum limit of 44 mm set by the international standard. Fracture mechanisms found by scanning electron microscopy (SEM) attested the relevance of increasing the fiber content for applications in MASs. The results of stand-alone tests showed that the control (0 vol%) and samples with 20 vol% TVFs absorbed the highest impact energy (Eabs) (212-176 J), and consequently displayed limit velocity (VL) values (213-194 m/s), when compared with 40 vol% fiber composites. However, the macroscopic evaluation found that, referring to the control samples, the plain epoxy shattered completely. In addition, for 10 and 20 vol% TVFs, the composites were fragmented or exhibited delamination fractures, which compromised their physical integrity. On the other hand, composites with 30 and 40 vol% TVFs, whose Eabs and VL varied between 166-130 J and 189-167 m/s, respectively, showed the best physical stability. The SEM images indicated that for composites with 10 and 20 vol% TVFs, the fracture mode was predominantly brittle due to the greater participation of the epoxy resin and the discrete action of the fibers, while for composites with 30 and 40 vol% TVFs, there was activation of more complex mechanisms such as pullout, shearing, and fiber rupture. These results indicate that the TVF composite has great potential for use in bulletproof vests.

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The main modifications of thermal and colorimetric parameters after thermal aging of DGEBA/TETA system (plain epoxy) and fique-fiber woven fabric-reinforced epoxy composites are described. As a preliminary study, thermal analysis was carried out on epoxy matrix composites reinforced with 15, 30, 40 and 50% fique-fiber woven fabric. After this previous analysis, the 40% composite was chosen to be thermally aged, at 170 °C. Three exposure times were considered, namely, 0, 72, 120 and 240 h. Samples were studied by thermogravimetric analysis (TGA), differential thermal analysis (DTA), differential scanning calorimetry (DSC), thermomechanical analysis (TMA) and colorimetry analysis. Significant color changes were observed after thermal aging combined with oxidation. It was also found that the thermal behavior of the plain epoxy showed greater resistance after thermal exposure. By contrast, the composites were more sensitive to temperature variations as a result of thermal stresses induced between fique fibers and the epoxy matrix.

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AIMS: To correlate the 'Residual Cancer Burden' (RCB) index with overall survival (OS) and disease-free survival (DFS) in women undergoing neoadjuvant chemotherapy at the Cancer Institute of the State of São Paulo. METHODS: We analysed the medical records of patients with breast cancer who underwent neoadjuvant chemotherapy and breast surgery, from 2011 to December 2017. Variables analysed were age, clinical and pathological staging, molecular subtype, number of recurrences or metastases, number of deaths, value and class of the RCB index. We used the Kaplan-Meier and the log-rank statistics to evaluate the possible association between RCB and OS and DFS. A regression model was used to determine the independent association of the RCB with the outcomes controlling for confounding factors. RESULTS: 347 patients were included in the analysis with a mean age of 49.39 years. Initial clinical staging was T3 in 57.9% of patients and 43.8% of patients had N1 axillary status. Survival analysis showed a statistically significant better prognosis for the RCB 0 (pCR) subgroup compared with RCB 1, 2 and 3 (log rank p=0.01). In a multivariate analysis, only the RCB classification showed a statistically significant correlation with DFS (RCB 1, HR 6.9, CI 1.9 to 25.4, p=0.004; RCB 2, HR 4.2, CI 1.6 to 10.8, p=0.03; and RCB 3, HR 7.6, CI 2.76 to 20.8, p=0.00). CONCLUSION: We demonstrated a positive and significant relationship between the RCB index and the risk of relapse and death.

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Fiber-reinforced composites are among the most investigated and industrially applied materials. Many studies on these composites using fibers, especially with natural fibers, were made in response to an urgent action for ambient preservation. A particularly relevant situation exists nowadays in the area of materials durability. In this respect, no studies on water-immersion-accelerated aging in fique fiber-epoxy composites are reported. This work aimed to fill this gap by investigating the epoxy matrix composites reinforced with 40 vol% fique fabric. The epoxy matrix and the composite, both unaged and aged, were characterized by weight variation, water absorption, morphology, colorimetry (CIELAB method), Fourier transform infrared spectroscopy (FTIR) and dynamic-mechanical analysis (DMA). The main results were that degradation by water presents appearance of complex microfibril structures, plasticization of epoxy resin, and debonding of the fique fiber/epoxy matrix. The most intense color change was obtained for the water-immersion-aged epoxy by 1440 h. Cole-Cole diagrams revealed the heterogeneity of the materials studied.

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Objective: To analyze the coping strategies used by primary healthcare (PHC) professionals. Methods: A cross-sectional, descriptive-analytical study realized with professionals working in primary healthcare units in São José do Rio Preto, a large city in the interior of São Paulo, Brazil. For data collection, we used an instrument developed by the researchers containing sociodemographic and professional variables, as well as the Problem Coping Modes Scale (EMEP). Results: We evaluated 333 PHC professionals. A difference was observed between the scores of the four coping strategies (p < 0.001), with the highest score for the problem-focused strategy (3.8) and the lowest score for the emotion-focused strategy (2.4). Physicians had the lowest scores in coping strategies focused on religious practices/fantastical thinking (p < 0.001) and pursuit of social support (p = 0.045), while community health agents had the highest scores in these coping strategies. Conclusions: Professionals working in PHC have different coping strategies for the problems and stressful situations experienced in the work environment. These strategies can involve more positive attitudes focused on confrontation and problem solving, and on emotional responses that involve attitudes of avoidance and denial of the problem.

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Titica vine (Heteropsis flexuosa) is a typical plant of the Amazon region commonly used for making baskets, bags, brooms and furniture, owing to its stiff fibers. In spite of its interesting properties, there is so far no reported information regarding the use of titica vine fibers (TVFs) in engineering composite materials. In this work, the TVF and its epoxy composites were for the first time physically, thermally and mechanically characterized. Additionally, the effect of two kinds of chemical treatments, one with sodium carbonate and one with calcium lignosulfonate, as well as different volume fractions, 10, 20, 30 and 40 vol%, of TVF-reinforced composites were assessed for corresponding basic properties. The thermogravimetric results of the composites reveal enhanced thermal stability for higher TVF content. In addition, the composite incorporated with 40 vol% of TVFs treated with sodium carbonate absorbed 19% more water than the composites with untreated fibers. By contrast, the calcium lignosulfonate treatment decreased water absorption by 8%. The Charpy and Izod impact tests showed that the composites, incorporated with the highest investigated volume fraction (40 vol%) of TVF, significantly increased the absorbed energy by 18% and 28%, respectively, compared to neat epoxy. ANOVA and Tukey statistical analyses displayed no direct influence of the chemical treatments on the energy absorption of the composites for either impact tests. SEM images revealed the main fracture mechanisms responsible for the performance of TVF composites.

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Stem cells are capable of generating various cell lines and can be obtained from adult or embryonic tissues for clinical therapies. Stem cells from deciduous dental pulp are among those that are easily obtainable from adult tissues and have been widely studied because of their ability to differentiate into a variety of cell lines in the presence of various chemical mediators. We have analyze the expression of several proteins related to the differentiation and proliferative potential of cell populations that compose the tooth germ of human fetuses. We evaluate 20 human fetuses of both genders. After being paraffin-embedded, cap and bell stages of tooth germ development were subjected to immunohistochemistry for the following markers: Oct-4, Nanog, Stat-3 and Sox-2. The studied antibodies showed nuclear or cytoplasmic immunnostaining within various anatomical structures and with various degrees of expression, indicating the action of these proteins during tooth development. We conclude that the interrelationship between these transcription factors is complex and associated with self-renewal and cell differentiation. Our results suggest that the expression of Oct-4, Nanog, Sox-2 and Stat-3 are related to differentiation in ameloblasts and odontoblasts.

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Diet has a strong effect, while suckling stimulus is believed not to influence breast milk fatty acids. The effect of dietary pattern and suckling on the fatty acid composition of Brazilian women's breast milk was studied. A cross-sectional study was conducted with low-income women living in the central region of Brazil, where dietary DHA is not readily available. Fore and hind milk fatty acids were collected from 77 women on day 15+/-1 postpartum, and information on maternal characteristics and dietary habit was taken. The effect of suckling stimulus was measured by the changes between fore and hind milk. The mean body mass index (BMI) of volunteers was 23.7+/-3.2 kg/m(2), and the milk lipid concentration was 4.8+/-1.2 g/dl. A mixture of traditional and western type of dietary habit, high in fat and sugar was observed. The fatty acids of the subject's milk were 41.93+/-1.42% saturated, 33.31+/-1.67% monounsaturated and 25.03+/-5.23% polyunsaturated (wt/wt). The DHA level in the milk was 0.34+/-0.19%, similar to the values found in milk of many western societies. DHA and 18:3n-3 levels increased from fore to hind milk (p<0.05). Correlation existed mostly between dietary components and milk 16:0 and oleic acid (18:0). An analysis of classes of fatty acids in milk showed oleic acid (18:0) to present a negative correlation with all milk fatty acid classes. The results suggest that breast milk fatty acids of Brazilian women reflect a western maternal dietary pattern and are influenced by the suckling.

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