Formation of Negative Ions upon Dissociative Electron Attachment to the Astrochemically Relevant Molecule Aminoacetonitrile.

Aminoacetonitrile (NH2CH2CN, AAN) is a molecule relevant for interstellar chemistry and the chemical evolution of life. It is a very important molecule in the Strecker diagram explaining the formation of amino acids. In the present investigation, dissociative electron attachment to NH2CN was studied in a crossed electron-molecular beams experiment in the electron energy range from about 0 to 17 eV.

NCO(-), a key fragment upon dissociative electron attachment and electron transfer to pyrimidine bases: site selectivity for a slow decay process.

We report gas phase studies on NCO(-) fragment formation from the nucleobases thymine and uracil and their N-site methylated derivatives upon dissociative electron attachment (DEA) and through electron transfer in potassium collisions. For comparison, the NCO(-) production in metastable decay of the nucleobases after deprotonation in matrix assisted laser desorption/ionization (MALDI) is also reported. We show that the delayed fragmentation of the dehydrogenated closed-shell anion into NCO(-) upon DEA proceeds few microseconds after the electron attachment process, indicating a rather slow unimolecular decomposition.

Hyperglycemia increases the complicated infection and mortality rates during induction therapy in adult acute leukemia patients.

Objective: To determine the prevalence of hyperglycemia during induction therapy in adult patients with acute leukemia and its effect on complicated infections and mortality during the first 30 days of treatment.

Methods: An analysis was performed in a retrospective cohort of 280 adult patients aged 18 to 60 years with previously untreated acute leukemia who received induction chemotherapy from January 2000 to December 2009 at the Hemocentro de Pernambuco (HEMOPE), Brazil. Hyperglycemia was defined as the finding of at least one fasting glucose measurement > 100 mg/dL observed one week prior to induction therapy until 30 days after.

Dissociative electron attachment to the nitroamine HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine).

In the present study, dissociative electron attachment (DEA) measurements with gas phase HMX, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine, C4H8N8O8, have been performed by means of a crossed electron-molecular beam experiment. The most intense signals are observed at 46 and 176 u and assigned to NO2(-) and C3H6N5O4(-), respectively. Anion efficiency curves for 15 negatively charged fragments have been measured in the electron energy region from about 0-20 eV with an energy resolution of ~0.