Análise ultra-estrutural da túnica muscular do intestino delgado de cães preservado em diferentes meios

Foram avaliados 25 amostras da camada muscular do intestino delgado de cães, conservados em solução supersaturada de açúcar a 300%, glicerina a 98%, polivinil-pirrolidona a 5% e tintura de tiomersal 1:1000. As amostras foram mantidas conservadas por 45 dias e submetidas a análise ultra-estrutural por microscopia eletrônica de transmissão. Os meios não preservaram totalmente a integridade celular, sendo as soluções de açúcar a 300% e glicerina 98% as que melhor mantiveram as ultra-estruturas celulares.The present study evaluated twenty-five sarnples of the muscular layer of the small gut in dogs, which were preserved in a 300% sugar supersaturated. solution, 98% glycerin, 5% polyvinil-pirrolidona and tiomersal tincture at 1: 1000. The samples were maintained under conservation for 45 days and further submitted to ultrastructural assay by transmission electron microscopy. The cellular integrity was not entirely preserved when using the media, while the 300% sugar solution and 98% glycerin were the preservation conditions that better maintained the cellular ultrastructure

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements