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Time-resolved X-ray photoelectron spectroscopy (XPS) is used to track the photodissociation dynamics of 2-iodothiophene following 262 nm excitation. The transient XPS features include both direct ionization of the initially populated excited states and pronounced satellite peaks arising from shake-down processes. While the direct ionization signals exhibit only minimal energy shifts during C–I bond cleavage, the shake-down transitions undergo a substantial, 5 eV, shift over the reaction coordinate. By correlating these shifts with simulated C–I bond lengths, a direct structural mapping is established that reveals the exceptional sensitivity of shake-down channels to molecular geometry. These results demonstrate that shake-down transitions provide a new and powerful probe of ultrafast structural dynamics. 

Abstract Lipid nanoparticles (LNPs) are the most clinically advanced nonviral RNA-delivery vehicles, though challenges remain in fully understanding how LNPs interact with biological systems. In vivo, proteins form an associated corona on LNPs that redefines their physicochemical properties and influences delivery outcomes. Despite its importance, the LNP protein corona is challenging to study owing to the technical difficulty of selectively recovering soft nanoparticles from biological samples. Herein, we develop a quantitative, label-free mass spectrometry-based proteomics approach to characterize the protein corona on LNPs. Critically, this protein corona isolation workflow avoids artifacts introduced by the presence of endogenous nanoparticles in human biofluids. We apply continuous density gradient ultracentrifugation for protein-LNP complex isolation, with mass spectrometry for protein identification normalized to protein composition in the biofluid alone. With this approach, we quantify proteins consistently enriched in the LNP corona including vitronectin, C-reactive protein, and alpha-2-macroglobulin. We explore the impact of these corona proteins on cell uptake and mRNA expression in HepG2 human liver cells, and find that, surprisingly, increased levels of cell uptake do not correlate with increased mRNA expression in part due to protein corona-induced lysosomal trafficking of LNPs. Our results underscore the need to consider the protein corona in the design of LNP-based therapeutics. 

Coulomb explosion imaging (CEI) provides a direct means of imaging molecular geometry by correlating fragment ion momenta following the fragmentation of a molecular polycation. Here, we demonstrate the use of three-body covariance and four-body cumulant analysis to extract three-dimensional (3D) structural information from the X-ray-induced Coulomb explosion of tert-butyl iodide (C4H9I). Site-selective ionization at the iodine 4d edge with intense femtosecond soft X-ray pulses from an X-ray free-electron laser (XFEL) enables rapid charge buildup and molecular breakup. By correlating ionic fragments in the molecular frame, we isolate complete dissociation channels and reveal subtle structural changes, such as umbrella-type motion of the branched alkyl chain, during the ionization process. Comparison with point-charge simulations of the Coulomb explosion shows close agreement, validating the approach. These results establish covariance/cumulant mapping as a powerful strategy for imaging complex three-dimensional molecular structures and point the way toward time-resolved CEI using both XFEL and tabletop sources for capturing ultrafast structural dynamics. 

The purpose of the study was to examine the “after-effects” of a leadership training program on university students. Data were collected using both cross-sectional and case study methods, and by interviewing students. The data were tabulated and analyzed using descriptive statistics and analyses. The participants included both male and female students; most of them were in their early twenties; juniors, and held department-wide, college-wide, or university-wide positions. Moreover, the majority of participants indicated that they participated in the workshops offered because they wanted to improve their leadership skills. They also indicated that they learned one new thing; for instance, leadership skills; teamwork; managing people, and grant writing. Furthermore, they all indicated that they have used, at least some of the information that they received from the workshops, such as information on voluntary organizations; leadership skills; financial management; grant writing; how to network; and dealing with different types of persons in organizations. Also, all the respondents mentioned that they were doing one thing differently, such as flexibility in leading; how to prioritize activities and tasks; using conflict resolution information; paying more attention to team members; sharing information with networks; and encouraging colleagues to provide or contribute ideas in team meetings. The students made suggestions for future workshops, such as including students from other colleges; more role-playing in the delivery of the workshops, and starting workshops early. The study has provided additional knowledge as to what university students think about the after-effects of a leadership training program. 

Abstract Detection and remediation of stress in crops is vital to ensure agricultural productivity. Conventional forms of assessing stress in plants are limited by feasibility, delayed phenotypic responses, inadequate specificity, and lack of sensitivity during initial phases of stress. While mass spectrometry is remarkably precise and achieves high-resolution, complex samples, such as plant tissues, require time-consuming and biased depletion strategies to effectively identify low-abundant stress biomarkers. Here, we bypassed these reduction methods via a nano-omics approach, where gold nanoparticles were used to enrich time- and temperature-dependent stress-related proteins through biomolecular corona formation that were subsequently analyzed by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). This nano-omic approach was more effective than a conventional proteomic analysis using UHPLC- MS/MS for resolving biotic-stress induced responses at early stages of pathogen infection inArabidopsis thaliana, well before the development of visible phenotypic symptoms, as well as in distal tissues of pathogen infected plants at early timepoints. The enhanced sensitivity of this nano-omic approach enables the identification of stress-related proteins at early critical timepoints, providing a more nuanced understanding of plant-pathogen interactions that can be leveraged for the development of early intervention strategies for sustainable agriculture.