Soft X-ray spectroscopy as a probe for gas-phase protein structure:Electron impact ionization from within

Preservation of protein conformation upon transfer into the gas‐phase is key for structure determination of free single molecules, e.g. using X‐ray free‐electron lasers. In the gas phase, the helicity of melittin decreases strongly as the protein's protonation state increases. We demonstrate the sensitivity of soft X‐ray spectroscopy to the gas phase conformation of melittin cations ([melittin+qH]q+, q=2‐4) in a cryogenic linear radiofrequency ion trap. With increasing helicity we observe a decrease of the dominating carbon 1s‐* transition in the amide C=O bonds for non‐dissociative single ionization and an increase for non‐dissociative double ionization. As the underlying mechanism we identify inelastic electron scattering. Using an independent atom model we show that the more compact nature of the helical protein conformation substantially increases the probability for off‐site intramolecular ionization by inelastic Auger electron scattering

Dificuldades para obter informações da população de mulheres sobre aborto ilegal Difficulties encountered in gathering information on illegal abortion of women population

Qualquer tentativa de se investigar a prática de abortos ilegais deve lidar com o problema de estar perguntando às mulheres acerca de um tema delicado, sensível, com implicações múltiplas, o que leva a dificuldades para se obter informações verazes. O estudo realizado enfoca principalmente aspectos metodológicos de uma pesquisa realizada junto a uma população de mulheres de 15 a 49 anos de idade, com o objetivo de verificar a freqüência e as condições em que era feito o aborto provocado em uma região do Estado de São Paulo (Brasil). Foram entrevistadas, em seus domicílios, 1.955 mulheres. Utilizou-se um questionário estruturado e pré-testado. A maioria das entrevistadas declarou nunca ter abortado nem pensado em fazê-lo, enquanto 4% referiram alguma vez ter feito aborto; 16,7% disseram que, pelo menos uma vez, tomaram chá/remédio para menstruar. Entre as que acreditaram estar grávidas na ocasião, a maioria informou nunca ter abortado, apesar de terem menstruado quando ingeriram chá/remédio. Os resultados permitiram concluir que as mulheres tendem a omitir a informação sobre a prática de aborto quando perguntadas diretamente sobre isso. Especialmente aquelas que o induzem por ingestão de substâncias parecem não reconhecer esse ato como sendo uma forma de interromper a gestação.<br>Any attempt to study the practice of illegal abortion faces the problem of asking women about a delicate, sensitive issue that has many implications. This may make it difficult to obtain truthful information on the subject. Results related to methodological aspects are emphasized and their possible association with variables included in a cross-sectional study carried out among 1.955 women, of 15 to 49 years of age is analysed. The frequency and conditions under which induced abortion was performed in a region of S. Paulo State are investigated. The women were interviewed at home using a pre-tested, structured questionnaire. Most of the women interviewed declared they had never had an abortion nor had they thought of having one, and four percent referred to having had an induced abortion. However, another 16.7 percent said that they had taken tea or medicine at least once to bring on their menses. In this group, most of the women who thought they were pregnant at that time said they had had never an abortion, in spite of having bled after drinking tea or medicine. The results lead to the conclusion that women tend no omit information on the practice of abortion when questioned directly. This is especially true of those who use oral means to bring on their menses and who seemed not to consider this a way of inducing an abortion