Tandem Trapped Ion Mobility Spectrometry/Mass Spectrometry (tTIMS/MS) Reveals Sequence-Specific Determinants of Top-Down Protein Fragment Ion Cross Sections.

Top-down proteomics provides a straightforward approach to the level of proteoforms but remains technologically challenging. Using ion mobility spectrometry/mass spectrometry (IMS/MS) to separate top-down fragment ions improves signal/noise and dynamic range. Such applications, however, do not yet leverage the primary information obtained from IMS/MS, which is the characterization of the fragment ion structure by the measured momentum transfer cross sections.

Hybrid-virtual simulations for Canadian medical students during the COVID-19 pandemic.

Given the efficacy of simulations as a medical education tool, the inability to provide them during the COVID-19 pandemic may be detrimental to pre-clinical medical student learning. We developed hybrid simulations, where remote learner participants could direct an in-person assistant. This offered a learning opportunity that was more realistic than fully virtual simulations and abided by public health guidelines.

On the Preservation of Non-covalent Peptide Assemblies in a Tandem-Trapped Ion Mobility Spectrometer-Mass Spectrometer (TIMS-TIMS-MS).

Ion mobility spectrometry-mass spectrometry (IMS-MS) has demonstrated the ability to characterize structures of weakly-bound peptide assemblies. However, these assemblies can potentially dissociate during the IMS-MS measurement if they undergo energetic ion-neutral collisions. Here, we investigate the ability of tandem-trapped ion mobility spectrometry-mass spectrometry (TIMS-TIMS-MS) to retain weakly-bound peptide assemblies.

On the structural denaturation of biological analytes in trapped ion mobility spectrometry - mass spectrometry.

Key to native ion mobility/mass spectrometry is to prevent the structural denaturation of biological molecules in the gas phase. Here, we systematically assess structural changes induced in the protein ubiquitin during a trapped ion mobility spectrometry (TIMS) experiment. Our analysis shows that the extent of structural denaturation induced in ubiquitin ions is largely proportional to the amount of translational kinetic energy an ion gains from the applied electric field between two collisions with buffer gas particles.

Comparison of perinatal grief after dilation and evacuation or labor induction in second trimester terminations for fetal anomalies.

Objective: This study was undertaken to compare grief resolution after dilation and evacuation (D&E) or induction of labor (IOL) for second-trimester pregnancy termination.

Study Design: A prospective cohort of 49 women choosing second-trimester abortion caused by fetal anomalies by either medical IOL or D&E. Depression was evaluated by using the Edinburgh Postnatal Depression Scale and bereavement was assessed by using the Perinatal Grief Scale with follow-up to 12 months after pregnancy termination.