Coxiella burnetii Infection in Livestock, Pets, Wildlife, and Ticks in Latin America and the Caribbean: a Comprehensive Review of the Literature

Purpose of the Review Q fever , a bacterial zoonosis caused by Coxiella burnetii, is reported very heterogeneously in humans in Latin America. The objective of this study was to review the data on Coxiella burnetii Infection in animals in Latin America and the Caribbean. Recent Findings A comprehensive literature review was carried out in the 47 countries and territories of Latin America on various search engines and grouped into four groups: livestock, pets, wildlife, and ticks. Summary Thus, 113 studies were selected between 1950 and 2022. Among the 47 countries, only 25 (53%) had at least one publication related to C. burnetii infection in animals. The most productive country was Brazil (N = 51), followed by French Guiana (N = 21), and Colombia (N = 16). Studies in livestock from 20 countries have shown widely varying country-to-country rates of seroprevalence, ranging from 0 to 67%. Some studies from seven countries, especially French Guiana and Brazil, found antibodies and sometimes positive PCR in dogs and cats, generally in the context of investigations around human clustered cases. Knowledge remained fragmented about infection in wildlife from only five countries (Chile, Colombia, Brazil, French Guiana, and Uruguay). C. burnetii infection was identified by PCR in Chiroptera (7 species), Rodentia (6 species), Suina (2 species), Xenartha (1 species), Cingulata (1 species), and Perissodactyla (1 species). Studies on Coxiella sp. in ticks have been performed in 11 countries, mostly in Brazil, and mainly found Coxiella-like endosymbionts. Thus, data on C. burnetii infection in animals are sparse and incomplete in Latin America and the Caribbean, and more research is warranted

The cracking resistance and adhesion to dentine of dental restorative materials: a fracture mechanics approach

Accès au résumé via l'hyperlienDoctorat en sciences appliquées (FSA 3)--UCL, 200

The effect of dispersion and atomisation conditions on the compaction response of silicon nitride granules

The relationship between the dispersion conditions of silicon nitride slurries and the compaction behaviour of spray dried granules is reported in the case of two commercial powders. Two parameters have been retained: the solid loading, varied between 10 and 30 vol.% and the degree of stability of the suspension, controlled by adjustment of the pH

Morphology and fracture properties of toughened highly crosslinked epoxy composites: A comparative study between high and low Tg tougheners

The mechanical properties of an unmodified reference composite panel based on a highly crosslinked epoxy resin are compared with several corresponding toughened versions, all containing the same amount of representative hard or soft tougheners. The panels are prepared and tested under identical conditions. In terms of tougheners, soft MAM block copolymers and CTBN rubber are compared with two high glass transition temperature (Tg) amorphous thermoplastics, PES and phenoxy. The high Tg thermoplastic tougheners yield considerable improvements of the composites mechanical properties, especially the interlaminar fracture toughness, as compared to the reference panel. On the contrary, MAM and CTBN modification are much less effective. The analysis of the morphology strongly suggests that effective toughening of composite panels based on densely crosslinked epoxy resins requires the combination of at least two key factors: (i) a fine dispersion of the toughener and (ii) strong matrixtoughener and matrix-carbon fibers interfaces. The study provides valuable insights for the choice of suitable tougheners for high performance epoxy systems, based on the link with the physical toughening mechanisms

Bio-Sourced Poly l-Lactide-Flax Composites with Close to Maximum Stiffness at Low Fiber Content through Two-Stage Annealing

Poly l-Lactide (PLLA) composites with short flax fibers (from 0 to 10 wt/wt%)with close to maximum theoretical stiffness are prepared by melt-compounding and injection-molding followed by a two-step isothermal crystallization protocol that fully separates the nucleation and growth stages (Tammann). The use of fast chip scanning calorimetry for thermal characterization avoids the complicating issues of crystal reorganization during the cooling and heating steps between the isothermal stages. Flax fibers are very efficient and selective nucleating agents of PLLA favoring the ordered form. The resulting morphology exhibits trans-crystallization on the fibers surface, predominantly at fiber defects, with a clear reduction of crystal size and a very strong fiber matrix cohesion. Efficient nucleation further leads to a large reduction of the overall crystallization time. Avrami analysis evidences a reduction of crystal growth dimensionality, consistent with both optical and scanning electron microscopy. The high modulus of the composites is unambiguously related to the strong orientation of the fibers in the tensile direction, to their high aspect ratio and to the excellent matrix-fibers cohesion. On the other hand, the tensile strength and hardness appear isotropic within experimental uncertainty and are unfavorably influenced by the presence of the fibers and by the two-stage annealing

Study of fiber waviness in composite structures supported by simulation

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