Evaluation of three iterative algorithms for phase modulation regarding their application in concentrating light inside biological tissues for laser induced photothermal therapy

Grant No. UIDB/00645/2020The focusing of light through turbid media like biological tissues is strongly hindered by the scattering of light which limits its safe practice and application in medicine. In order to control this phenomenon, we shaped the incident wavefront using three algorithms including a four-element division algorithm, a partitioning algorithm, and simulated annealing to control, iteratively, a spatial light modulator (SLM). We have tested two different convergence criteria to achieve a focal point inside a turbid environment, made up of a mixture of agar and milk, set to mimic a specific depth of human skin, and provide comparison results. A camera and a lens are used to visualize the focal area and give feedback information to the algorithms. A discussion on the use of these algorithms and convergence criteria is presented, being focused on its convergence time and performance. Depending on the algorithm and operational parameters, improvements of 29% to 46% of the irradiance in the region of interest were accomplished.publishersversionpublishe

A rare case of colonic pseudolipomatosis

A 54-year-old man was referred to our department for colorectal cancer screening. The colonoscopy revealed, at the ascending colon, several white plaques, some confluent, interspersed with normal mucosa (Fig. 1). Biopsies were performed and the histopathological examination showed a fragment of polypoid colonic mucosa with optically empty vacuoles in the lamina propria (Fig. 2) and irregular cystic spaces of varying sizes, similar to adipocytes in the absence of inflammation or dysplasia. Colonic pseudolipomatosis is a benign and rare condition, with an estimated prevalence of 0.02-0.3 % in colonoscopic series, characterized by the presence of vacuoles with gas content in the lamina propria of the large intestine [1]. The incidence is more frequent between the sixth and seventh decade of life [2]. The pathogenesis remains unclear

Wood dimensional changes as consequences of its hygroscopic behavior

Wood has a strong hygroscopic behavior, with a huge variation of moisture content and dimension stability caused by modifications of the relative humidity and temperature of the surrounding air. This moisture relationship has an important influence on wood properties and performance. Many of the challenges of using wood as an engineering material arise from changes in moisture content or an abundance of moisture within the wood. Wood is dimensionally stable when moisture content is greater than the fiber saturation point (MCfs). Below MCfs wood changes dimension as it gains moisture (swells) or loses moisture (shrinks), because volume of the cell wall depends on the amount of bound water. With respect to dimensional stability, wood is an anisotropic material. It shrinks (or swells) most in the direction of the annual growth rings (tangentially), about half as much across the rings (radially), and only slightly along the grain (longitudinally). In this work, an experimental program was defined with the aim to evaluate the dimensional stability of three coniferous wood species: maritime pine (Pinus pinaster), scots pine (Pinus sylvestris) and spruce (Picea abies). Comparing the wood species, it is the Spruce (A) that presents higher dimensional changes, while it is the Maritime pine (P) that is more stable under moisture content variation. Tests results allow to conclude that the most important dimensional variation occurs in the first 24 hours

Locais de venda de medicamentos não sujeitos a receita médica: caracterização da população utente e do nível de satisfação com o atendimento

A possibilidade de venda de medicamentos não sujeitos a receita médica fora das farmácias provocou uma enorme revolução no sector. Esta medida visou, entre outros aspectos, a redução dos preços destes medicamentos e a melhoria da acessibilidade do consumidor a estes produtos, pelo aumento do número de postos de venda. No entanto, com a excepção do efeito sobre o preço dos medicamentos que esta medida teve, pouco se conhece sobre a qualidade dos serviços prestados nos locais de venda e a percepção sobre essa qualidade. Objectivo do estudo: caracterizar a população-utente de locais de venda de MNSRM e determinar o seu grau de satisfação com a organização e o atendimento prestado no local

Assessment of Wild Rocket (Diplotaxis tenuifolia (L.) DC.) Germplasm accessions by NGS identified SSR and SNP markers

Rocket is the common designation for two baby-leaf salad crops of the Brassicaceae family: Eruca sativa (L.) Cav., usually referred to as annual garden rocket, and Diplotaxis tenuifolia (L.) DC. commonly named to as perennial wild rocket. E. sativa is used for human consumption since antiquity. However, the growing consumer preference for D. tenuifolia is being accompanied by the fast increase in its production area and commercialization of new cultivars. Nevertheless, the worldwide number of wild rocket accessions maintained in germplasm collections is very reduced, the solution for which situation the project “REMIRucula” intends to contribute, establishing a germplasm collection at the INIAV, Oeiras, Portugal. Herein, we report on the establishment via next generation sequencing (NGS) of the first genome assembly of D. tenuifolia and the identification of specific single sequence repeat (SSR) and single nucleotide polymorphisms (SNP) loci for the establishment of specific DNA-markers for this species. A representative set of 87 D. tenuifolia and 3 E. sativa accessions were assessed by 5 SSR and 9 SNP-CAPS markers, allowing a drastic discrimination between both species and the establishment of unequivocal molecular fingerprints for the analyzed accessions. The non-discrimination within six pairs and one trio of D. tenuifolia accessions is discussed.info:eu-repo/semantics/publishedVersio

Personal exposure to particle concentration in a busy street

info:eu-repo/semantics/publishedVersio

Addressing the non-linearity and singularity phenomena of stress-based optimal design of material microstructures

Material design is an active research field since composites have met increasingly interest, for instance, in lightweight construction as it happens in aerospace industry. One assumes in the present work a given macroscopic stress or strain field (one that may occur at a certain point of a macro-structure) and computes through homogenization the micro-stress distribution across the two (weaker and stronger) composite constituents mixed in a unit-cell domain which is representative of a periodic heterogeneous material. Stress gradients depend a lot of design details but typically the stress field is highly non-linear. In the frame of finite element models for material microstructures one pursues here an investigation about mesh convergence. Since stress distribution is strongly design dependent, that motivates one to pursue optimal design of the material microstructure to comply with admissible stress criteria. The inverse homogenization method using density-based topology optimization is applied here for such purpose. This is quite a challenge not only because of the aforementioned non-linearity of the stress field but also due to the singularity phenomena which one overcomes using standard relaxation techniques. Some preliminary results are obtained in order to get some insight into the fine structure of composite materials and the influence of the stresses therein