Exploring the ultrafast and isomer-dependent photodissociation of iodothiophenes via site-selective ionization.

C-I bond extension and fission following ultraviolet (UV, 262 nm) photoexcitation of 2- and 3-iodothiophene is studied using ultrafast time-resolved extreme ultraviolet (XUV) ionization in conjunction with velocity map ion imaging. The photoexcited molecules and eventual I atom products are probed by site-selective ionization at the I 4d edge using intense XUV pulses, which induce multiple charges initially localized to the iodine atom. At C-I separations below the critical distance for charge transfer (CT), charge can redistribute around the molecule leading to Coulomb explosion and charged fragments with high kinetic energy. At greater C-I separations, beyond the critical distance, CT is no longer possible and the measured kinetic energies of the charged iodine atoms report on the neutral dissociation process. The time and momentum resolved measurements allow determination of the timescales and the respective product momentum and kinetic energy distributions for both isomers, which are interpreted in terms of rival 'direct' and 'indirect' dissociation pathways. The measurements are compared with a classical over the barrier model, which reveals that the onset of the indirect dissociation process is delayed by ∼1 ps relative to the direct process. The kinetics of the two processes show no discernible difference between the two parent isomers, but the branching between the direct and indirect dissociation channels and the respective product momentum distributions show isomer dependencies. The greater relative yield of indirect dissociation products from 262 nm photolysis of 3-iodothiophene (cf. 2-iodothiophene) is attributed to the different partial cross-sections for (ring-centred) π∗ ← π and (C-I bond localized) σ∗ ← (n/π) excitation in the respective parent isomers.

A qualitative feasibility study of a prototype patient-centered video intervention to increase uptake of cancer genetic testing among Black Americans.

BACKGROUND: Health advances due to developments in genomic medicine are unequally experienced in the USA; racial differences in the uptake of genetic testing are one factor in this disparity. In collaboration with Black patients and diverse health care providers, we are developing a patient-centered video intervention to increase cancer genetic testing among eligible Black Americans. The objective of the pilot work is to explore the acceptability of and support for the intervention and key content components. METHODS: In order to create a patient-centered video intervention prototype, we conducted a targeted, secondary analysis of 47 coded transcripts from video-taped qualitative interviews with people with a known genetic or inherited cancer risk. The review focused on decision-making, testing experiences, and perceived value of genetic testing. We subsequently generated a 15-min video montage of content from 9 diverse (age, gender, race) participants. We used the prototype video as prompt material for semi-structured interviews with 10 Black patients who had undergone genetic testing in the last 2 years and 10 racially diverse providers (genetic counselors, a nurse, and medical oncologists) who provide management recommendations for high-risk patients. Interviews sought to understand the acceptability of a video intervention to enhance informed decision-making by Black patients and key elements for intervention efficacy. RESULTS: Study participants were generally positive about the prototype video and provided guidance for intervention development. Interviewed patients prioritized perceived authenticity and relatability of video participants. The presentation of patients' perspectives on testing, their experiences of testing, and the benefits of having test results were all seen as useful. The benefits of testing for self and family were identified as important considerations. Privacy concerns and science skepticism were identified as germane issues, with guidance to present barriers to testing alongside possible solutions. The inclusion of clinicians was seen as potentially useful but with caution that clinicians are not universally trusted. CONCLUSIONS: Study findings provided critical input for the creation of a professionally produced, tailored intervention video for a randomized clinical trial with Black Americans to evaluate the influence on uptake of genetic testing. The interviews suggest the acceptability and potential utility of an authentic, realistic, and tailored, patient-centered video intervention to increase consideration and uptake of genetic testing.

Assessing an innovative method to promote learning from patient narratives: Findings from a field experiment in ambulatory care.

OBJECTIVE: To assess whether an online interactive report designed to facilitate interpretation of patients' narrative feedback produces change in ambulatory staff learning, behavior at the individual staff and practice level, and patient experience survey scores. DATA SOURCES AND SETTING: We studied 22 ambulatory practice sites within an academic medical center using three primary data sources: 333 staff surveys; 20 in-depth interviews with practice leaders and staff; and 9551 modified CG-CAHPS patient experience surveys augmented by open-ended narrative elicitation questions. STUDY DESIGN: We conducted a cluster quasi-experimental study, comparing 12 intervention and 10 control sites. At control sites, narratives were delivered free-form to site administrators via email; at intervention sites, narratives were delivered online with interactive tools for interpretation, accompanied by user training. We assessed control-versus-intervention site differences in learning, behavior, and patient experience scores. DATA COLLECTION: Staff surveys and interviews were completed at intervention and control sites, 9 months after intervention launch. Patient surveys were collected beginning 4 months pre-launch through 9 months post-launch. We used control-versus-intervention and difference-in-difference analyses for survey data and thematic analysis for interview data. PRINCIPAL FINDINGS: Interviews suggested that the interface facilitated narrative interpretation and use for improvement. Staff survey analyses indicated enhanced learning from narratives at intervention sites (29% over control sites' mean of 3.19 out of 5 across eight domains, p < 0.001) and greater behavior change at staff and practice levels (31% and 21% over control sites' means of 3.35 and 3.39, p < 0.001, respectively). Patient experience scores for interactions with office staff and wait time information increased significantly at intervention sites, compared to control sites (3.7% and 8.2%, respectively); however, provider listening scores declined 3.3%. CONCLUSIONS: Patient narratives presented through structured feedback reporting methods can catalyze positive changes in staff learning, promote behavior change, and increase patient experience scores in domains of non-clinical interaction.

Multichannel photodissociation dynamics in CS2 studied by ultrafast electron diffraction.

The structural dynamics of photoexcited gas-phase carbon disulfide (CS2) molecules are investigated using ultrafast electron diffraction. The dynamics were triggered by excitation of the optically bright 1B2(1Σu+) state by an ultraviolet femtosecond laser pulse centred at 200 nm. In accordance with previous studies, rapid vibrational motion facilitates a combination of internal conversion and intersystem crossing to lower-lying electronic states. Photodissociation via these electronic manifolds results in the production of CS fragments in the electronic ground state and dissociated singlet and triplet sulphur atoms. The structural dynamics are extracted from the experiment using a trajectory-fitting filtering approach, revealing the main characteristics of the singlet and triplet dissociation pathways. Finally, the effect of the time-resolution on the experimental signal is considered and an outlook to future experiments provided.

Parenting Children with Cystic Fibrosis: Developmental Acquisition of Expertise.

OBJECTIVE: This study was designed to increase our understanding of parents' experiences managing the needs of their children with cystic fibrosis (CF) and to identify potential gaps in services. METHOD: We used grounded dimensional analysis of anonymous survey data obtained from a quality improvement initiative conducted by the Cystic Fibrosis Foundation (CFF). The Patient and Family Experience of Care (PFEC) survey was administered continuously at 125 CF care centers throughout the United States in 2017. The subsample of data for this study was completed by 80 parents/caregivers of children with CF (younger than 18 years). RESULTS: Two unifying themes emerged from parents' survey responses: (1) parents' expertise expands continually as they learn and adapt to changes in their children's maturity or health and (2) parental expertise is sometimes visible or invisible to clinicians. Parents' expertise evolved with their children's development. Visible to care teams was at-home care, e.g., respiratory treatments and medications. Less visible were intangible management activities, e.g., social processes, emotions, and concerns that were omnipresent for parents but seldom disclosed to or seen/recognized by clinicians. Themes, such as the quality of encounters with care teams, progressive nature of CF, and hope derived from advances in research, were associated with specific contextual factors. CONCLUSION: The findings expand our understanding of lived parental experiences of CF across childhood and offer direction for future quality improvement and research. Online parent surveys offer a valuable tool to identify unmet needs across subgroups of families affected by chronic childhood health conditions.

Time resolved detection of the S(1D) product of the UV induced dissociation of CS2.

The products formed following the photodissociation of UV (200 nm) excited CS2 are monitored in a time resolved photoelectron spectroscopy experiment using femtosecond XUV (21.5 eV) photons. By spectrally resolving the electrons, we identify separate photoelectron bands related to the CS2 + hν → S(1D) + CS and CS2 + hν → S(3P) + CS dissociation channels, which show different appearance and rise times. The measurements show that there is no delay in the appearance of the S(1D) product contrary to the results of Horio et al. [J. Chem. Phys. 147, 013932 (2017)]. Analysis of the photoelectron yield associated with the atomic products allows us to obtain a S(3P)/S(1D) branching ratio and the rate constants associated with dissociation and intersystem crossing rather than the effective lifetime observed through the measurement of excited state populations alone.

Photodissociation dynamics of methyl iodide probed using femtosecond extreme ultraviolet photoelectron spectroscopy.

Femtosecond pump-probe photoelectron spectroscopy measurements using an extreme ultraviolet probe have been made on the photodissociation dynamics of UV (269 nm) excited CH3I. The UV excitation leads to population of the 3Q0 state which rapidly dissociates. The dissociation is manifested as shifts in the measured photoelectron kinetic energy that map the extending C-I bond. The increased energy available in the XUV probe relative to a UV probe means the dynamics are followed over the chemically important region as far as C-I bond lengths of approximately 4 Å.

Photodissociation dynamics of CH3I probed via multiphoton ionisation photoelectron spectroscopy.

The dissociation dynamics of CH3I is investigated on the red (269 nm) and blue (255 nm) side of the absorption maximum of the A-band. Using a multiphoton ionisation probe in a time-resolved photoelectron imaging experiment we observe very different dynamics at the two wavelengths, with significant differences in the measured lifetime and dynamic structure. The differences are explained in terms of changes in excitation cross-sections of the accessible 3Q0 and 1Q1 states and the subsequent dynamics upon each of them. The measurements support the existing literature on the rapid dissociation dynamics on the red side of the absorption maximum at 269 nm which is dominated by the dynamics along the 3Q0 state. At 255 nm we observe similar dynamics along the 3Q0 state but also a significant contribution from the 1Q1 state. The dynamics along the 1Q1 potential show a more complex structure in the photoelectron spectrum and a significantly increased lifetime, indicative of a more complex reaction pathway.

Mapping the Complete Reaction Path of a Complex Photochemical Reaction.

We probe the dynamics of dissociating CS_{2} molecules across the entire reaction pathway upon excitation. Photoelectron spectroscopy measurements using laboratory-generated femtosecond extreme ultraviolet pulses monitor the competing dissociation, internal conversion, and intersystem crossing dynamics. Dissociation occurs either in the initially excited singlet manifold or, via intersystem crossing, in the triplet manifold. Both product channels are monitored and show that, despite being more rapid, the singlet dissociation is the minor product and that triplet state products dominate the final yield. We explain this by a consideration of accurate potential energy curves for both the singlet and triplet states. We propose that rapid internal conversion stabilizes the singlet population dynamically, allowing for singlet-triplet relaxation via intersystem crossing and the efficient formation of spin-forbidden dissociation products on longer timescales. The study demonstrates the importance of measuring the full reaction pathway for defining accurate reaction mechanisms.