BackgroundScorpionism is a serious public health problem in Brazil. Although cases of envenomation by scorpions are frequent in Brazil, Tityus silvestris – found throughout the Amazon region – is considered of minor medical significance and with only a few descriptions in the literature. This article aims to describe for the first time the epidemiological characteristics and clinical manifestations of scorpion stings by T. silvestris that occurred in eastern Brazilian Amazon.MethodsA prospective and observational study was carried out on 13 confirmed cases of T. silvestris envenomation registered from 2007 to 2011 in the cities of Belém and Ananindeua, Pará state, Brazil.ResultsThe stings occurred mainly during daytime, at domiciliary environment, and the scorpions were found in clothing, fruits or vegetables. Envenomation was more frequent in the age group between 21 and 30 years old, upper limbs were more affected and medical aid was usually provided within two hours. Men and women were equally affected. Regarding severity, ten patients were classified as Class I and three patients as Class II according to the Scorpion Consensus Expert Group. Local manifestations were present in all patients, being pain the most common symptom. Mild systemic manifestations including nausea, vomiting, somnolence, malaise and prostration were observed in three victims. Symptomatic treatment of pain was offered to all patients, and only one received specific antivenom. All victims had a favorable outcome.ConclusionsTo the best of our knowledge, this study is the first to report the systemic symptomatology of envenomation by T. silvestris in the Brazilian Amazon, highlighting the medical relevance of the species in this region. Further research on the venom and clinical manifestations of envenomation by T. silvestris should be conducted in order to verify the relevance of this species to public health.

According to the World Health Organization, snakebites are considered neglected diseases. Bothrops, the genus most frequently implicated in envenomations in Brazil, includes the species B. marajoensis Hoge, 1966, part of the complex B. atrox, which is found in the savannas of Marajó Island, Pará state, Brazil, a region that presents scarce epidemiological data. This work reports the first case of hemorrhagic stroke in a child, attributed to delayed medical care after snakebite envenoming by Bothrops marajoensis in Anajás city, Marajó Island, Pará, Brazil, which led to permanent hemiplegia as a sequela.

Five novel Eu(III)-β-diketonate complexes containing ruthenocene ancillary ligands (1,1′-bis(diphenylphosphoryl)-ruthenocene�RcBPO) were synthesized and characterized. The coordination compounds presented the general formula [Eu(βdik) 3 (RcBPO)], where β-dik stands for 2-thenoyltrifluoroacetonate (tta), 3-benzoyl-1,1,1-trifluoroacetone (btf), 2-dibenzoylmethanate (dbm), 2-acetyl-1,3-indandionate (aind), and 2-benzoyl-1,3-indandionate (bind), and RcBPO stands for 1,1′-bis-(diphenylphosphoryl)ruthenocene. The [Eu(aind) 3 (RcBPO)] complex crystallizes in a monoclinic Cc non-centrosymmetric space group with the europium site environment, assuming a bicapped trigonal prism coordination polyhedron with the symmetry point group close to C 2v . Photoluminescent properties for the solid-state samples were described in terms of excitation, emission, lifetime decay curves, and intrinsic and overall quantum yields. The replacement of the two coordinated H 2 O molecules by the RcBPO ancillary ligand leads to great enhancements of the overall quantum yields (Q Eu L ), with the minimum increment by a factor of 5 for the case of [Eu(btf) 3 (RcBPO)] and the maximum enhancement of 270 times for the case of the [Eu(dbm) 3 (RcBPO)] complex. In addition, theoretical calculations were carried out to model the spectroscopic properties of the investigated compounds. To obtain theoretical Judd−Ofelt parameters (Ω λ , λ = 2, 4, and 6) and intramolecular energy transfer rates, the JOYSpectra web platform was employed using the structure obtained from density functional theory calculations. Hence, a rate equation model provided theoretical overall quantum yields, which are in great agreement with measured data.

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