Theoretical Investigations on the Plasmon-Mediated Dissociation of Small Molecules in the Presence of Silver Atomic Wires.

Plasmonic nanoparticles can promote bond activation in adsorbed molecules under relatively benign conditions via excitation of the nanoparticle's plasmon resonance. As the plasmon resonance often falls within the visible light region, plasmonic nanomaterials are a promising class of catalysts. However, the exact mechanisms through which plasmonic nanoparticles activate the bonds of nearby molecules are still unclear. Herein, we evaluate Ag8-X2 (X = N, H) model systems via real-time time-dependent density functional theory (RT-TDDFT), linear response time-dependent density functional theory (LR-TDDFT), and Ehrenfest dynamics in order to better understand the bond activation processes of N2 and H2 facilitated by the presence of the atomic silver wire under excitation at the plasmon resonance energies. We find that dissociation is possible for both small molecules at high electric field strength. Activation of each adsorbate is symmetry- and electric field-dependent, and H2 activates at lower electric field strengths than N2. This work serves as a step toward understanding the complex time-dependent electron and electron-nuclear dynamics between plasmonic nanowires and adsorbed small molecules.

Should we be talking about guidelines with patients? A qualitative analysis in metastatic breast cancer.

BACKGROUND: Little data exist on perceptions of guideline-based care in oncology. This qualitative analysis describes patients' and oncologists' views on the value of guideline-based care as well as discussing guidelines when making metastatic breast cancer (MBC) treatment decisions. PATIENTS AND METHODS: In-person interviews completed with MBC patients and community oncologists and focus groups with academic oncologists were audio-recorded and transcribed. Two coders utilized a content analysis approach to analyze transcripts independently using NVivo. Major themes and exemplary quotes were extracted. RESULTS: Participants included 20 MBC patients, 6 community oncologists, and 5 academic oncologists. Most patients were unfamiliar with the term "guidelines." All patients desired to know if they were receiving guideline-discordant treatment but were often willing to accept this treatment. Five themes emerged explaining this including trusting the oncologist, relying on the oncologist's experiences, being informed of rationale for deviation, personalized treatment, and openness to novel therapies. Physician discussions regarding the importance of guidelines revealed three themes: consistency with scientific evidence, insurance coverage, and limiting unusual practices. Oncologists identified three major limitations in using guidelines: lack of consensus, inability to "think outside the box" to personalize treatment, and lack of guideline timeliness. Although some oncologists discussed guidelines, it was often not considered a priority. CONCLUSIONS: Patients expressed a desire to know whether they were receiving guideline-based care but were amenable to guideline-discordant treatment if the rationale was made clear. Providers' preference to limit discussions of guidelines is discordant with patients' desire for this information and may limit shared decision-making.

Computational Study of Methane C-H Activation by Diiminopyridine Nitride/Nitridyl Complexes of 3d Transition Metals and Main-Group Elements.

The C-H bond activation of methane using Ph,MePDI-M≡N [Ph,MePDI = 2,6-(PhN═CMe)2C5H3N] (M = V, Mn, Fe, Co, Ni, Al, or P) has been studied via three reaction pathways: [2σ + 2π] addition, hydrogen atom abstraction (HAA), and direct insertion. The activating ligand is a nitride/nitridyl (N), with diiminopyridine (PDI) as the supporting ligand. Calculations show reasonable C-H activation barriers for Co, Ni, Al, and P Ph,MePDI nitrides, complexes that favor an HAA pathway. Electrophilic Ph,MePDI nitride complexes of the earlier metals with a nucleophilic actor ligand-V, Mn, Fe-follow a [2σ + 2π] addition pathway for methane activation. Free energy barriers for methyl migration, Ph,MePDI-M(CH3)═NH → Ph,MePDI-M-N(H)CH3, are also interesting in the context of alkane functionalization; discriminating factors in this mechanistic step include the strengths of the σ-bond and metal-actor ligand π-bond that are broken and the electrophilicity of the actor ligand to which methyl migrates.

Evaluating electronic structure methods for accurate calculation of 19 F chemical shifts in fluorinated amino acids.

The ability of electronic structure methods (11 density functionals, HF, and MP2 calculations; two basis sets and two solvation models) to accurately calculate the 19 F chemical shifts of 31 structures of fluorinated amino acids and analogues with known experimental 19 F NMR spectra has been evaluated. For this task, BHandHLYP, ωB97X, and Hartree-Fock with scaling factors (provided within) are most accurate. Additionally, the accuracy of methods to calculate relative changes in fluorine shielding across 23 sets of structural variants, such as zwitterionic amino acids versus side chains only, was also determined. This latter criterion may be a better indicator of reliable methods for the ultimate goal of assigning and interpreting chemical shifts of fluorinated amino acids in proteins. It was found that MP2 and M062X calculations most accurately assess changes in shielding among analogues. These results serve as a guide for computational developments to calculate 19 F chemical shifts in biomolecular environments. © 2017 Wiley Periodicals, Inc.

Integrated Safety and Health Promotion among Correctional Workers and People Incarcerated: A Scoping Review.

Improving safety and health for correctional workers and people who are incarcerated are widespread yet separate initiatives. Correctional workers and people who are incarcerated experience similar challenges involved with poor workplaces and living conditions, including mental health crises, violence, stress, and chronic health issues, and the available resources lack integration with respect to safety and health promotion. This scoping review sought to contribute to an integrated approach for correctional system safety and health resources and identify studies of correctional resources that address health promotion among correctional workers and people who are incarcerated. Guided by PRISMA, a search of gray literature, also termed peer-reviewed literature, published between 2013-2023 (n = 2545) was completed, and 16 articles were identified. Resources primarily targeted individual and interpersonal levels. At every level of intervention, resources improved the environment for both workers and those incarcerated, with trends of less conflict, more positive behaviors, and improved relations, access to care, and feelings of safety. The corrections environment is impacted by changes from both workers and people who are incarcerated and should be examined using a holistic approach. Future health and safety resources should target the larger correctional environment by utilizing practices, policies, and procedures to improve safety and health for incarcerated people and workers.

Guideline Concordance With Durvalumab in Unresectable Stage III Non-Small Cell Lung Cancer: A Single Center Veterans Hospital Experience.

BACKGROUND: Durvalumab is recommended by national guidelines for patients with unresectable stage III non-small cell lung cancer (NSCLC) following concurrent chemoradiation therapy (CRT). Nonadherence to guidelines is associated with adverse outcomes. We studied the adherence and identified barriers to durvalumab usage at the Birmingham Veterans Affairs Medical Center (VAMC) Oncology Clinic in Alabama. METHODS: Using retrospective analysis, we assessed the use of consolidative durvalumab among veterans at Birmingham VAMC. The health records of all veterans with stage III unresectable NSCLC from October 2017 to August 2019 were reviewed. Data collected included demographics, barriers to CRT initiation and completion, durvalumab usage, and reasons for not prescribing durvalumab. RESULTS: In our data review, 34 patients were found to have stage III unresectable NSCLC. Twenty (58.8%) of those 34 initiated CRT, but only 16 (47.1%) completed CRT treatment and 7 (20.6%) underwent further treatment with durvalumab. Of the 14 patients who did not initiate CRT, the most common reasons were poor performance status and/or the presence of comorbidities. Of the evaluable cohort of 34, 11 (32.4%) patients with stage III NSCLC received durvalumab. Of the 9 eligible patients who did not receive durvalumab, the most common reasons cited were toxicities experienced during or following CRT (11.8%). CONCLUSIONS: Just one-third of patients were eligible to receive durvalumab at Birmingham VAMC. This was likely due to the difference between clinical trial and real-world patient populations. Interventions to address socioeconomic and system level barriers to improve our center's delivery of lung cancer treatment are planned.

Impact of Travel Time on Health Care Costs and Resource Use by Phase of Care for Older Patients With Cancer.

PURPOSE: Many community cancer clinics closed between 2008 and 2016, with additional closings potentially expected. Limited data exist on the impact of travel time on health care costs and resource use. METHODS: This retrospective cohort study (2012 to 2015) evaluated travel time to cancer care site for Medicare beneficiaries age 65 years or older in the southeastern United States. The primary outcome was Medicare spending by phase of care (ie, initial, survivorship, end of life). Secondary outcomes included patient cost responsibility and resource use measured by hospitalization rates, intensive care unit admissions, and chemotherapy-related hospitalization rates. Hierarchical linear models with patients clustered within cancer care site (CCS) were used to determine the effects of travel time on average monthly phase-specific Medicare spending and patient cost responsibility. RESULTS: Median travel time was 32 (interquartile range, 18-59) minutes for the 23,382 included Medicare beneficiaries, with 24% of patients traveling longer than 1 hour to their CCS. During the initial phase of care, Medicare spending was 14% higher and patient cost responsibility was 10% higher for patients traveling longer than 1 hour than those traveling 30 minutes or less. Hospitalization rates were 4% to 13% higher for patients traveling longer than 1 hour versus 30 minutes or less in the initial (61 v 54), survivorship (27 v 26), and end-of-life (310 v 286) phases of care (all P < .05). Most patients traveling longer than 1 hour were hospitalized at a local hospital rather than at their CCS, whereas the converse was true for patients traveling 30 minutes or less. CONCLUSION: As health care locations close, patients living farther from treatment sites may experience more limited access to care, and health care spending could increase for patients and Medicare.

New Insights into the Dynamics of Zwitterionic Micelles and Their Hydration Waters by Gigahertz-to-Terahertz Dielectric Spectroscopy.

Gigahertz-to-terahertz spectroscopy of macromolecules in aqueous environments provides an important approach for identifying their global and transient molecular structures, as well as directly assessing hydrogen-bonding. We report dielectric properties of zwitterionic dodecylphosphocholine (DPC) micelles in aqueous solutions over a wide frequency range, from 50 MHz to 1.12 THz. The dielectric relaxation spectra reveal different polarization mechanisms at the molecular level, reflecting the complexity of DPC micelle-water interactions. We have made a deconvolution of the spectra into different components and combined them with the effective-medium approximation to separate delicate processes of micelles in water. Our measurements demonstrate reorientational motion of the DPC surfactant head groups within the micelles, and two levels of hydration water shells, including tightly and loosely bound hydration water layers. From the dielectric strength of bulk water in DPC solutions, we found that the number of waters in hydration shells is approximately constant at 950 ± 45 water molecules per micelle in DPC concentrations up to 400 mM, and it decreases after that. At terahertz frequencies, employing the effective-medium approximation, we estimate that each DPC micelle is surrounded by a tightly bound layer of 310 ± 45 water molecules that behave as if they are an integral part of the micelle. Combined with molecular dynamics simulations, we determine that tightly bound waters are directly hydrogen-bonded to oxygens of DPC, while loosely bound waters reside within 4 Å of micellar atoms. The dielectric response of DPC micelles at terahertz frequencies yields, for the first time, experimental information regarding the largest scale, lowest frequency collective motions in micelles. DPC micelles are a relatively simple biologically relevant system, and this work paves the way for more insight into future studies of hydration and dynamics of biomolecular systems with gigahertz-to-terahertz spectroscopy.