Eighty-four staphylococcal isolates were obtained from milk samples from cows, sheep, goats, and buffalo with subclinical mastitis and from colonization samples from ostriches. The animals were hosted in 18 small dairy herds and an ostrich breeding located in 10 municipalities of the state of Rio de Janeiro, Brazil. Thirty isolates were identified as Staphylococcus aureus by biochemical and molecular techniques and were comparatively characterized by phenotypic and genotypic methods. The molecular characterization by pulsed-field gel electrophoresis (PFGE), spa typing, and multilocus sequence typing (MLST) revealed five clonal types (PFGE A, spa type t359, sequence type 747 [ST747]; PFGE B, spa type t1180, ST750; PFGE C, spa type t605, ST126; PFGE D, spa type t127, ST751; and PFGE F, spa type t002, ST5). None of the isolates harbored the Panton-Valentine leukocidin or exfoliative toxin D gene. The detection of major clone A (in 63% of the isolates) in different herds, among all animal species studied, and in infection and colonization samples evidenced its geographical spread among Rio de Janeiro State and no host preference among the animal species. Comparison with S. aureus from a human origin suggested that all but one clone found in the present study might be animal specific.

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The formation of hydrates in dispersions of cubic tricalcium aluminate (C 3 A)-calcium hydroxide-gypsum was observed using soft X-ray transmission microscopy. This technique allows the continuous imaging of the hydration process without the introduction of drying artifacts. Within minutes, microcrystalline hydrates covered the C 3 A particles but over time large prismatic ettringite crystals are precipitated suppressing the microcrystalline hydrates. Within the resolution of the technique, no protective hydrated layer on the surface of C 3 A particles was observed.

Lithium nitrate has been used to prevent and to mediate the expansion caused by alkali‐silica reaction (ASR). However, there is limited information on how it affects the existing reaction products caused by ASR. The aim of the present work is to determine the modifications caused by the LiNO3 treatment on the structure of the gel produced by ASR. ASR gel samples obtained from a concrete dam were exposed to an aqueous solution of lithium nitrate and sodium hydroxide with molar LiNO3/ NaOH=0.74, and the resulting products were analyzed by X‐ray diffraction, infrared spectroscopy, and solid‐state nuclear magnetic resonance of 29Si, 23Na, and 7Li. The treatment of the gel samples produces significant structural modifications in ASR products. A new amorphous silicate compound incorporating Li+ ions is formed, with an average silicate network that can be described as linear in contrast with the layered structure of the original gel. This elimination of the layered structure after the Li‐based treatments may be related to the reduction of the tendency of the gel to expand. Also, several crystalline compounds containing potassium indicate the release of this species from the original ASR gel.