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Mechanical forces acting within the plant body that can mold flower shape throughout development received little attention. The palette of action of these forces ranges from mechanical pressures on organ primordia at the microscopic level up to the twisting of a peduncle that promotes resupination of a flower at the macroscopic level. Here, we argue that without these forces acting during the ontogenetic process, the actual flower phenotype would not be achieved as it is. In this review, we concentrate on mechanical forces that occur at the microscopic level and determine the fate of the flower shape by the physical constraints on meristems at an early stage of development. We thus highlight the generative role of mechanical forces over the floral phenotype and underline our general view of flower development as the sum of interactions of known physiological and genetic processes, together with physical aspects and mechanical events that are entangled towards the shaping of the mature flower.
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The Duchenne smile hypothesis is that smiles that include eye constriction (AU6) are the product of genuine positive emotion, whereas smiles that do not are either falsified or related to negative emotion. This hypothesis has become very influential and is often used in scientific and applied settings to justify the inference that a smile is either true or false. However, empirical support for this hypothesis has been equivocal and some researchers have proposed that, rather than being a reliable indicator of positive emotion, AU6 may just be an artifact produced by intense smiles. Initial support for this proposal has been found when comparing smiles related to genuine and feigned positive emotion; however, it has not yet been examined when comparing smiles related to genuine positive and negative emotion. The current study addressed this gap in the literature by examining spontaneous smiles from 136 participants during the elicitation of amusement, embarrassment, fear, and pain (from the BP4D+ dataset). Bayesian multilevel regression models were used to quantify the associations between AU6 and self-reported amusement while controlling for smile intensity. Models were estimated to infer amusement from AU6 and to explain the intensity of AU6 using amusement. In both cases, controlling for smile intensity substantially reduced the hypothesized association, whereas the effect of smile intensity itself was quite large and reliable. These results provide further evidence that the Duchenne smile is likely an artifact of smile intensity rather than a reliable and unique indicator of genuine positive emotion.
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Chronic obstructive pulmonary disease (COPD) is regarded as one of the leading causes of morbidity and mortality across the world, yet its proper diagnosis remains a challenge. Community-based population studies conducted in North and South America, Europe, Australia, and Asia have revealed that 10% to 12% of adults aged 40 years or older have evidence of persistent airflow limitation on spirometry, but only 20% to 30% of these subjects have been diagnosed with COPD. These studies collectively suggest that approximately 70% of COPD worldwide may be underdiagnosed. Conversely, other studies have shown that between 30% and 60% of patients with a previous physician diagnosis of COPD do not actually have the disease, and hence they have been overdiagnosed. In this review, we define under- and overdiagnosis and explore the prevalence and the burden of under- and overdiagnosis of COPD on both patients and healthcare systems. We further describe potential solutions to reduce the incidence of under- and overdiagnosis of COPD.
Assuntos
Erros de Diagnóstico/estatística & dados numéricos , Uso Excessivo dos Serviços de Saúde/estatística & dados numéricos , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Ásia , Austrália , Europa (Continente) , Humanos , Internacionalidade , América do Norte , América do Sul , EspirometriaRESUMO
O objetivo do presente estudo foi comparar as características superficiais de amostras de Titânio (Ti) porosas (Ti-P) e de Ti Denso (Ti-D), usando MEV e rugosímetro 3D. O experimento foi realizado em triplicata (n= 3). Inicialmente foram obtidas imagens em MEV de alta definição das superfícies. Na sequência, as amostras eram analisadas em rugosímetro 3D utilizando parâmetros de amplitude (Sa e St) que indicam a rugosidade média, um parâmetro espacial (Str), que indica a uniformidade da textura, e um parâmetro híbrido (Sdr) que indica a área superficial disponível. Fotomicrografias mostraram que o Ti-P apresentava poros abertos e amplos. Além disso, nesta superfície foram observados valores de Sa e de St bastante altos (35.3 ± 1.20 μm e 315.67 ± 14.36 μm, respectivamente), valor de Str de 0.81 ± 0.08 (tendendo a 1, ou seja, isotrópico) e de Sdr de 42.57% ± 0.67, enquanto o Ti-D apresentava uma superfície lisa e valores de rugosidade bastante baixos (Sa e St de 0.17 ± 0.04 e de 5.31 ± 0.49, respectivamente), Str de 0.00 ± 0.00 (anisotrópico) e Sdr de apenas 0.14% ± 0.04. Portanto, pode-se concluir que as superfícies de Ti poroso apresentaram características topográficas bastante distintas do Ti Denso, como poros abertos e amplos, maior rugosidade, isotropia e maior área superficial disponível.
The aim of this study was to compare surface topographical features of porous Ti (Ti-P) and Dense Ti (Ti-D) samples, using SEM and 3D perfilometer. The study was performed in triplicate (n = 3). First, SEM high-definition images of both surfaces were obtained. Then, the samples were analysed by 3D perfilometer, using amplitude parameters (Sa and St), a Spatial parameter (Str) and a Hybrid parameter (Sdr). Open and wide pores were observed on Ti-P surface by photomicrographs. Furthermore, Ti-P showed higher values of amplitude roughness (Sa and St values of 35.3 ± 1.20 μm and 315.67 ± 14.36 μm, respectively), higher Str value (0.81± 0.08, tending to 1, i.e, isotropic) and Sdr value of 42.57% ± 0.67. On the other hand, Ti-D presented a smooth surface and very low roughness values (Sa and St, 0.17 ± 0.04 and 5.31 ± 0.49, respectively), Str 0.00 ± 0.00 (anisotropic) and Sdr 0.14% ± 0.04. So, it can be concluded that Ti-P andTi-D surfaces presented very distinct topographic features, especially open and wide pores, higher roughness, isotropy and higher available surface area.
Assuntos
Metalurgia , Titânio , TopografiaRESUMO
OBJECTIVE: This study aimed at investigating the influence of the porous titanium (Ti) structure on the osteogenic cell behaviour. MATERIALS AND METHODS: Porous Ti discs were fabricated by the powder metallurgy process with the pore size typically between 50 and 400 microm and a porosity of 60%. Osteogenic cells obtained from human alveolar bone were cultured until subconfluence and subcultured on dense Ti (control) and porous Ti for periods of up to 17 days. RESULTS: Cultures grown on porous Ti exhibited increased cell proliferation and total protein content, and lower levels of alkaline phosphatase (ALP) activity than on dense Ti. In general, gene expression of osteoblastic markers-runt-related transcription factor 2, collagen type I, alkaline phosphatase, bone morphogenetic protein-7, and osteocalcin was lower at day 7 and higher at day 17 in cultures grown on porous Ti compared with dense Ti, a finding consistent with the enhanced growth rate for such cultures. The amount of mineralized matrix was greater on porous Ti compared with the dense one. CONCLUSION: These results indicate that the porous Ti is an appropriate substrate for osteogenic cell adhesion, proliferation, and production of a mineralized matrix. Because of the three-dimensional environment it provides, porous Ti should be considered an advantageous substrate for promoting desirable implant surface-bone interactions.