Geographic distance to Commission on Cancer-accredited and nonaccredited hospitals in the United States.

PURPOSE: The Commission on Cancer (CoC) establishes standards to support multidisciplinary, comprehensive cancer care. CoC-accredited cancer programs diagnose and/or treat 73% of patients in the United States. However, rural patients may experience diminished access to CoC-accredited cancer programs. Our study evaluated distance to hospitals by CoC accreditation status, rurality, and Census Division. METHODS: All US hospitals were identified from public-use Homeland Infrastructure Foundation-Level Data, then merged with CoC-accreditation data. Rural-Urban Continuum Codes (RUCC) were used to categorize counties as metro (RUCC 1-3), large rural (RUCC 4-6), or small rural (RUCC 7-9). Distance from each county centroid to the nearest CoC and non-CoC hospital was calculated using the Great Circle Distance method in ArcGIS. FINDINGS: Of 1,382 CoC-accredited hospitals, 89% were in metro counties. Small rural counties contained a total of 30 CoC and 794 non-CoC hospitals. CoC hospitals were located 4.0, 10.1, and 11.5 times farther away than non-CoC hospitals for residents of metro, large rural, and small rural counties, respectively, while the average distance to non-CoC hospitals was similar across groups (9.4-13.6 miles). Distance to CoC-accredited facilities was greatest west of the Mississippi River, in particular the Mountain Division (99.2 miles). CONCLUSIONS: Despite similar proximity to non-CoC hospitals across groups, CoC hospitals are located farther from large and small rural counties than metro counties, suggesting rural patients have diminished access to multidisciplinary, comprehensive cancer care afforded by CoC-accredited hospitals. Addressing distance-based access barriers to high-quality, comprehensive cancer treatment in rural US communities will require a multisectoral approach.

Porphyrin Aggregation under Homogeneous Conditions Inhibits Electrocatalysis: A Case Study on CO2 Reduction.

Metalloporphyrins are widely used as homogeneous electrocatalysts for transformations relevant to clean energy and sustainable organic synthesis. Metalloporphyrins are well-known to aggregate due to π-π stacking, but surprisingly, the influence of aggregation on homogeneous electrocatalytic performance has not been investigated previously. Herein, we present three structurally related iron meso-phenylporphyrins whose aggregation properties are different in commonly used N,N-dimethylformamide (DMF) electrolyte. Both spectroscopy and light scattering provide evidence of extensive porphyrin aggregation under conventional electrocatalytic conditions. Using the electrocatalytic reduction of CO2 to CO as a test reaction, cyclic voltammetry reveals an inverse dependence of the kinetics on the catalyst concentration. The inhibition extends to bulk performance, where up to 75% of the catalyst at 1 mM is inactive compared to at 0.25 mM. We additionally report how aggregation is perturbed by organic additives, axial ligands, and redox state. Periodic boundary calculations provide additional insights into aggregate stability as a function of metalloporphyrin structure. Finally, we generalize the aggregation phenomenon by surveying metalloporphyrins with different metals and substituents. This study demonstrates that homogeneous metalloporphyrins can aggregate severely in well-solubilizing organic electrolytes, that aggregation can be easily modulated through experimental conditions, and that the extent of aggregation must be considered for accurate catalytic benchmarking.

Validity of a common measure of intimate partner violence perpetration: Impact on study inference in trials in low- and middle-income countries.

Background: In lower-and middle-income countries (LMICs), studies of interventions to reduce intimate partner violence (IPV) perpetration are expanding yet measurement equivalence of the construct has not been established. We assessed the measurement equivalence of physical and sexual IPV perpetration used in recent trials in LMICs and tested the impact of non-invariance on trial inference. Methods: With data from three recent intervention trials among men (sample size 505-1537 across studies), we calculated tetrachoric correlations among items and used multiple-group confirmatory factor analysis to assess invariance across arms and over time. We also assessed treatment effects adjusting for covariate imbalance and using inverse probability to treatment weights to assess concordance of invariant measures with published results, where warranted. Findings: The average correlation among items was high and increased over time with several items in two studies showing correlations ≥0.85 at endline. Increases in correlation for physical IPV were concentrated in the treatment arm in two of the studies. The increase in correlation in sexual IPV differed by arm across studies. Across all studies, a correlated two-factor solution was the best fitting model according to the EFAs and CFAs. One study demonstrated measurement invariance across arms and over time. In two of the studies, longitudinal measurement non-invariance was detected in the intervention arms. In post hoc testing, one study attained invariance with a one-factor model and study inference was concordant with published findings. The other study did not attain even partial invariance. Conclusion: Common measures of physical and sexual IPV perpetration cannot be used for valid effect estimation without further refinement. The study highlights the need for an expanded item set, content validity assessments, further measurement invariance testing, and then consistent use of the item sets in future intervention trials to support accurate inference on the effectiveness of IPV perpetration prevention interventions.

Designing barrier-free metal/MoS2 contacts through electrene insertion.

Transition-metal dichalcogenides (TMDCs), including MoS2, have great potential in electronics applications. However, achieving low-resistance metal contacts is a challenge that impacts their performance in nanodevices due to strong Fermi-level pinning and the presence of a tunnelling barrier. As a solution, we explore a strategy of inserting monolayers of alkaline-earth sub-pnictide electrenes with a general formula of [M2X]+e- (M = Ca, Sr, Ba; X = N, P, As, Sb) between the TMDC and the metal. These electrenes possess two-dimensional sheets of charge on their surfaces that can be readily donated when interfaced with a TMDC semiconductor, thereby lowering its conduction band below the Fermi level and eliminating the Schottky and tunnelling barriers. In this work, density-functional theory (DFT) calculations were performed for metal/electrene/MoS2 heterojunctions for all stable M2X electrenes and both Au and Cu metals. To identify the material combinations that provide the most effective Ohmic contact, the charge transfer, band structure, and electrostatic potential were computed. Linear correlations were found between the charge donated to the MoS2 and both the electrene surface charge and work function. Overall, Ca2N appears to be the most promising electrene for achieving an Ohmic metal/MoS2 contact due to its high surface charge density.

Rural comprehensive cancer care: Qualitative analysis of current challenges and opportunities.

PURPOSE: While limited resources can make high-quality, comprehensive, coordinated cancer care provision challenging in rural settings, rural cancer patients often rely on local hospitals for care. To develop resources and strategies to support high-quality local cancer care, it is critical to understand the current experiences of rural cancer care physicians, including perceived strengths and challenges of providing cancer care in rural areas.  METHODS: Semi-structured interviews were conducted with 13 cancer providers associated with all 12 non-metropolitan/rural Iowa hospitals that diagnose or treat >100 cancer patients annually. Iterative thematic analysis was conducted to develop domains. FINDINGS: Participants identified geographic proximity and sense of community as strengths of local care. They described decision-making processes and challenges related to referring patients to larger centers for complex procedures, including a lack of dedicated navigators to facilitate and track transfers between institutions and occasional lack of respect from academic physicians. Participants reported a desire for strengthening collaborations with larger urban/academic cancer centers, including access to educational opportunities, shared resources and strategies to collect and monitor data on quality, and clinical trials. CONCLUSIONS: Rural cancer care providers are dedicated to providing high-quality care close to home for their patients and would welcome opportunities to increase collaboration with larger centers to improve coordination and comprehensiveness of care, collect and monitor data on quality of care, and access continuing education opportunities. Further research is needed to develop implementation approaches that will extend resources, services, and expertise to rural providers to facilitate high-quality cancer care for all cancer patients.

Predictive validity of the Academy of Nutrition and Dietetics/American Society for Parenteral and Enteral Nutrition indicators to diagnose malnutrition tool in hospitalized adults: a cohort study.

BACKGROUND: The lack of a widely accepted, broadly validated tool for diagnosing malnutrition in hospitalized patients limits the ability to assess the integral role of nutrition as an input and outcome of health, disease, and treatment. OBJECTIVES: This study aimed to evaluate the predictive validity of the Academy of Nutrition and Dietetics/American Society for Parenteral and Enteral Nutrition (ASPEN) indicators to diagnose malnutrition (AAIM) tool and determine if it can be simplified. METHODS: A prospective cohort study was conducted from August 2019 to September 2022 with 32 hospitals in United States. At baseline, 290 adult patients were evaluated for a diagnosis of malnutrition using the AAIM tool, which assesses weight loss, inadequate energy intake, subcutaneous fat and muscle loss, edema, and hand grip strength. Healthcare outcomes were extracted from the medical record: composite incidence of emergency department (ED) visits and hospital readmissions within 90 d postdischarge; length of hospital stay (LOS); and Medicare Severity Disease Related Group (MS-DRG) relative weight (i.e., healthcare resource utilization). We used multilevel, multivariable negative binomial or generalized linear regression models to evaluate relationships between malnutrition diagnosis and healthcare outcomes. RESULTS: After adjusting for disease severity and acuity and sociodemographic characteristics, individuals diagnosed with severe malnutrition had a higher incidence rate of ED visits and hospital readmissions (incidence rate ratio: 1.89; 95% CI: 1.14, 3.13; P = 0.01), and individuals diagnosed with moderate malnutrition had a 25.2% longer LOS (95% CI: 2.0%, 53.7%; P = 0.03) and 15.1% greater healthcare resource utilization (95% CI: 1.6%, 31.9%; P = 0.03) compared with individuals with no malnutrition diagnosis. Observed relationships remained consistent when only considering malnutrition diagnoses supported by at least 2 of these indicators: weight loss, subcutaneous fat loss, muscle wasting, and inadequate energy intake. CONCLUSIONS: Findings from this multihospital study confirm the predictive validity of the original or simplified AAIM tool and support its routine use for hospitalized adult patients. This trial was registered at clinicaltrials.gov as NCT03928548 (https://classic. CLINICALTRIALS: gov/ct2/show/NCT03928548).

Validity of a Common Measure of Intimate Partner Violence Perpetration: Impact on Study Inference in Trials in Low- and Middle-Income Countries.

Background: In lower-and middle-income countries (LMICs), studies of interventions to reduce intimate partner violence (IPV) perpetration are expanding, yet measurement equivalence of the IPV perpetration construct that is the primary outcome in these investigations has not been established. We assessed the measurement equivalence of physical and sexual IPV perpetration item sets used in recent trials in LMICs and tested the impact of non-invariance on trial inference. Methods: With data from three intervention trials among men (sample size 505-1537 across studies) completed in 2019, we calculated tetrachoric correlations among items and used multiple-group confirmatory factor analysis to assess invariance across arms and over time. We also assessed treatment effects adjusting for covariate imbalance and using inverse probability to treatment weights to assess concordance of invariant measures with published results, where warranted. Findings: The average correlation among items measuring IPV perpetration was high and increased by 0.03 to 0.15 for physical IPV and 0.07 to 0.17 for sexual IPV over time with several items in two studies showing correlations ≥ 0.85 at endline. Increases in the degree of correlation for physical IPV were concentrated in the treatment arm in two of the studies. The increase in correlation in sexual IPV differed by arm across studies. Across all studies, a correlated two-factor solution was the best fitting model according to the EFAs and CFAs. One study demonstrated measurement invariance across arms and over time. In two of the studies, longitudinal measurement non-invariance was detected in the intervention arms. In post hoc testing, one study attained invariance with a one-factor model and study inference was concordant with published findings. The other study did not attain even partial invariance. Conclusion: Common measures of physical and sexual IPV perpetration cannot be used validly for comparisons across treatment versus control groups over time without further refinement. The study highlights the need for an expanded item set, content validity assessments, further measurement invariance testing, and then consistent use of the item sets in future intervention trials to ensure valid inferences regarding the effectiveness of IPV perpetration prevention interventions within and across trials.

Completion of a Nutrition-Focused Physical Exam with hospitalized adults and pediatric patients: Secondary analysis of a prospective cohort study.

BACKGROUND: Nutrition-Focused Physical Exam (NFPE) feasibility is not well-studied. We describe registered dietitian nutritionist (RDN)-reported NFPE completion for hospitalized adult and pediatric patients overall and by assessment parameters. METHODS: Trained RDNs systematically conducted NFPEs for hospitalized adult and pediatric patients during the Academy of Nutrition and Dietetics and American Society for Parenteral and Enteral Nutrition Indicators to diagnose Malnutrition multisite cohort study (ClinicalTrials.gov: NCT03928548). RDNs reported their ability to evaluate assessment sites for subcutaneous fat and muscle loss, fluid accumulation, and micronutrient status and to complete handgrip strength (adults and children ≥6 years) and mid-upper arm circumference measurements (children). RDNs noted if they could complete the full NFPE; if not, they noted challenges. We descriptively summarized results and used multilevel logistic regression models to examine relationships between patient characteristics and NFPE completion. RESULTS: RDNs from 39 adult and 29 pediatric US hospitals conducted NFPEs for 327 adults and 214 children aged 1 month to 17.9 years. RDNs reported completing the examination for 44% (n = 145) of adults and 15% (n = 33) of children. They successfully evaluated 25 of 27 and 19 of 26 unique NFPE components in >80% of adults and children, respectively. Common reasons the full NFPE was not completed were limited mobility in adults and patient refusal in children. RDNs had lower odds of completing NFPEs in adults with lower vs higher education levels or higher vs lower nutrition complexity and in younger vs older children. CONCLUSION: RDNs evaluated NFPE components for a high proportion (>80%) of hospitalized patients.

Impact of COVID-19 visitation policies and hospital capacity on discharge readiness in medicine patients.

Background: COVID-19 impacted the experience of being hospitalized with the widespread adoption of strict visitation policies to ensure healthcare worker safety. One result was decreased time of caregivers at the bedside of hospitalized patients. Objective: To understand the impact of pandemic-related system effects on patient-reported discharge preparation. Design: This mixed methods study included interviews with a sample of discharged patients during April 2020, and quantitative hospital data from April 2020 to February 2021. Participants: 616 patients completed a measure of discharge readiness on their day of discharge and 38 patients completed interviews about their discharge experiences. Main measures: Readiness for discharge (RHDS), visitation policies, ward structure changes, COVID-19-unit census, time into the COVID-19 pandemic, patient characteristics (age, sex, race/ethnicity), admission type (planned/unplanned, for COVID-19), and discharge destination (home, home health, skilled nursing). Key results: Adult patients aged 30-45 (vs. young and older adult patients) and those being discharged to places other than home (e.g., skilled nursing facility) or to out-of-state residences report lower readiness (p < 0.05) on RHDS. Patient interviews revealed some gaps in discharge communication but, overall, patients expressed high discharge readiness and few concerns about how COVID-19 system changes impacted their discharge preparation. Conclusions: While there is some evidence that visitation policies and unit census may impact patient perceptions of discharge preparation, personal characteristics contributed more significantly to discharge readiness than system changes during COVID-19. Participant interviews demonstrated agreement, as most participants were discharged home and identified strong personal feelings of readiness for discharge.Clinical trials registration: ClinicalTrials.gov ID NCT04248738, https://clinicaltrials.gov/ct2/show/NCT04248738. Supplementary Information: The online version contains supplementary material available at 10.1007/s44250-023-00060-8.

Effect of [n]-Helicene Length on Crystal Packing.

Chiral π-conjugated organic molecules hold potential for emerging technologies as they are capable of introducing novel functionalities into electronic devices owing to their strong chiroptical properties. However, capitalizing on chiral molecules for electronic devices is reliant on their molecular packing-a factor that impacts their charge-transport properties. The solid-state behavior of molecules is sensitive to subtle differences in molecular interactions, chirality, and shape, but these relationships are not fully understood. Here, we employ crystal structure prediction (CSP) as a tool to probe the lattice-energy landscape for a family of chiral organic molecules: [n]helicenes, where n ranges from 3 to 12. Our results show excellent agreement between the CSP landscapes and experimentally reported structures. By analyzing the packing motifs within the polymorph landscapes, we begin to develop an understanding of how helicene length affects the shape and π-π stacking interactions seen in the polymorphs. Furthermore, we propose how helicene length can be used as a tool to design new functional organic electronics.

Nickel-Catalyzed O-Arylation of Primary or Secondary Aliphatic Alcohols with (Hetero)aryl Chlorides: A Comparison of Ni(I) and Ni(II) Precatalysts.

A comparative experimental and computational study examining the interplay of the ancillary ligand structure and Ni oxidation state in the Ni-catalyzed C(sp2)-O cross-coupling of (hetero)aryl chlorides and primary or secondary aliphatic alcohols is presented, focusing on PAd-DalPhos (L1)-, CyPAd-DalPhos (L2)-, PAd2-DalPhos (L3)-, and DPPF (L4)-ligated [(L)NiCl]n (n = 1 or 2) and (L)Ni(o-tol)Cl precatalysts. Both L1 and L2 were found to outperform the other ligands examined, with the latter proving to be superior overall. While Ni(II) precatalysts generally outperformed Ni(I) species, in some instances the catalytic abilities of Ni(I) precatalysts were competitive with those of Ni(II). Density-functional theory calculations indicate the favorability of a Ni(0)/Ni(II) catalytic cycle featuring turnover-limiting C-O bond reductive elimination over a Ni(I)/Ni(III) cycle involving turnover-limiting C-Cl oxidative addition.

Low thermal expansion of layered electrides predicted by density-functional theory.

Layered electrides are a unique class of materials with anionic electrons bound in interstitial regions between thin, positively charged atomic layers. While density-functional theory is the tool of choice for computational study of electrides, there has to date been no systematic comparison of density functionals or dispersion corrections for their accurate simulation. There has also been no research into the thermomechanical properties of layered electrides, with computational predictions considering only static lattices. In this work, we investigate the thermomechanical properties of five layered electrides using density-functional theory to evaluate the magnitude of thermal effects on their lattice constants and cell volumes. We also assess the accuracy of five popular dispersion corrections with both planewave and numerical atomic orbital calculations.

Comparison of Density-Functional Theory Dispersion Corrections for the DES15K Database.

While density-functional theory (DFT) remains one of the most widely used tools in computational chemistry, most functionals fail to properly account for the effects of London dispersion. Hence, there are many popular post-self-consistent methods to add a dispersion correction to the DFT energy. Until now, the most popular methods have never been compared on equal footing due to not being implemented in the same electronic structure packages. In this work, we performed a large-scale benchmarking study, directly comparing the accuracy of the exchange-hole dipole moment (XDM), D3BJ, D4, TS, MBD, and MBD-NL dispersion models when applied to the recent DES15K database of nearly 15,000 molecular complexes at both expanded and compressed geometries. Our study showed similarly good performance for all dispersion methods (except TS) when applied to neutral complexes. However, they all performed worse for ionic complexes, particularly those involving dications of alkaline earth metals, due to systematic overbinding by the base PBE0 density functional. Investigation of the largest outliers also revealed that only the MBD and MBD-NL methods demonstrate surprising errors for complexes involving alkali metal cations at compressed geometries where they tended to significantly overbind. As we would expect minimal dispersion binding for such complexes, we further investigated the origins of these errors for the potential energy curve of a model cation-π complex. Overall, there is little choice between the XDM, D3BJ, D4, MBD, and MBD-NL dispersion methods for most systems. However, the MBD-based methods are not recommended for complexes involving organic species and alkali or alkaline earth metal cations, for example when modeling Li+ intercalation into graphite.

Measurement invariance of the Center for Epidemiologic Studies Scale-Depression within and across six diverse intervention trials.

Depression, a major contributor to the global burden of disease, is an outcome of interest in clinical trials. Researchers and clinicians note that depression often presents differently across cultures, posing challenges in the accurate measurement of depressive symptoms across populations. A commonly used self-administered screening tool to measure depressive symptoms, the Center for Epidemiologic Studies Scale-Depression (CES-D), has been translated into dozens of languages and used in thousands of studies, yet gaps remain in our understanding of its factor structure and invariance across studies and over time in the context of interventions. In this secondary analysis, we sampled six recent trials from lower- and middle-income countries to (a) establish the factor structure of the CES-D, (b) assess measurement invariance of the CES-D across treatment versus control arms and over time, (c) examine cross-study invariance, and (d) identify items that may be driving potential noninvariance. We performed exploratory/confirmatory factor analysis to establish the factor structure of the CES-D within each trial and used multiple group confirmatory analysis to assess within-study cross-arm/cross-time and cross-study invariance. After removal of positive affect items, a unidimensional model performed equivalently over time and across arms within trials, but exhibited noninvariance across trials, supporting prior literature describing differences in factor structure of the scale across populations. While our findings suggest that the CES-D without positive affect items is a valid measure of depressive symptoms within trials in our sample, caution is warranted in interpreting the findings of meta-analyses and multisite/multicountry studies using the CES-D as an outcome measure. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Life on the Frontlines: Caregiver Experience of Pediatric Cerebrospinal Shunt Malfunction.

BACKGROUND: We aimed to characterize the caregiver experience in the detection and evaluation of pediatric cerebrospinal shunt malfunction. METHODS: In this descriptive qualitative study, we recruited English-speaking caregivers of children aged five years or less in collaboration with a stakeholder organization. Semistructured interviews were completed; content targeted the caregiver experience of shunt malfunction. Interviews were audio-recorded, transcribed, and deidentified. Qualitative data were analyzed using a conventional content analysis approach. RESULTS: We enrolled 20 caregivers (n = 20 mothers). The median child age at the time of the interview was 2.8 years; about half (n = 11) were born prematurely and the majority (n = 15) had shunts placed at age less than six months. Caregiver experiences of shunt malfunction were grouped into three major themes: (1) my error could be life or death: the high stakes of shunt malfunction and the ambiguity of malfunction symptoms exacerbated baseline caregiver vigilance; (2) finding and engaging people who can help: hurdles during malfunction evaluation included locating trusted clinicians and advocating for parental intuition; and (3) how the shunt defines our family: caregivers described evolving expertise and modifications made to everyday life due to the threat of malfunction. CONCLUSIONS: In this study, caregivers highlighted the challenges associated with recognizing shunt malfunction, accessing necessary treatment, and the impact of their child's shunt on family life. Future work should leverage these findings to inform counseling about shunt malfunction, develop interventions to better support families in shunt malfunction identification, and educate medical providers.

A novel murine model of pyoderma gangrenosum reveals that inflammatory skin-gut crosstalk is mediated by IL-1ß-primed neutrophils.

Pyoderma gangrenosum (PG) is a debilitating skin condition often accompanied by inflammatory bowel disease (IBD). Strikingly, ~40% of patients that present with PG have underlying IBD, suggesting shared but unknown mechanisms of pathogenesis. Impeding the development of effective treatments for PG is the absence of an animal model that exhibits features of both skin and gut manifestations. This study describes the development of the first experimental drug-induced mouse model of PG with concomitant intestinal inflammation. Topical application of pyrimidine synthesis inhibitors on wounded mouse skin generates skin ulcers enriched in neutrophil extracellular traps (NETs) as well as pro-inflammatory cellular and soluble mediators mimicking human PG. The mice also develop spontaneous intestinal inflammation demonstrated by histologic damage. Further investigations revealed increased circulating low density IL-1ß primed neutrophils that undergo enhanced NETosis at inflamed tissue sites supported by an increase in circulatory citrullinated histone 3, a marker of aberrant NET formation. Granulocyte depletion dampens the intestinal inflammation in this model, further supporting the notion that granulocytes contribute to the skin-gut crosstalk in PG mice. We anticipate that this novel murine PG model will enable researchers to probe common disease mechanisms and identify more effective targets for treatment for PG patients with IBD.

Periodic trends in the structural, electronic, and transport properties of electrenes.

Two-dimensional layered electrides are a class of atomically thin materials in which the anion is an excess electron rather than a negatively charged ion. These excess electrons form delocalized sheets of charge surrounding each layer of the material. A well-known example is Ca2N; its identification and characterization has triggered an avalanche of studies aimed at broadening applications of electrides. Ca2N is only one member of the M2X family of materials, with M being an alkaline-earth metal and X belonging to the pnictogen group, which can be exfoliated to form single- or few-layer electrenes. The goal of this study is to systematically investigate the monolayer and bilayer properties for this family of materials. Density-functional calculations reveal linear relationships between surface and interstitial charges, work functions, exfoliation energies, and Ewald energies. Using the Landauer formalism, informed by rigorous electron-phonon scattering calculations, we also investigate the electronic transport characteristics of the monolayer and bilayer electrenes. Our findings indicate that the nitrogen-based electrenes (Ca2N, Sr2N, and Ba2N) are more conductive than their counterparts involving heavier pnictogens. The results of this study highlight underlying periodic trends in electrene properties that can help identify which materials would be best suited for particular applications.

Factors Associated with IRB Review Time in a Non-Federally Funded Study Using an sIRB of Record.

From 2018 to 2020, U.S. federal mandates began requiring the use of a single institutional review board (sIRB) of record for federally funded, multisite studies. With an interest in the efficiency of site activation, we compared the frequency with which local review and approval and three different reliance options (ways to establish a reliance agreement between the sIRB and the relying institution) were used during this period in a multisite, non-federally funded study (ClinicalTrials.gov identifier: NCT03928548). Using general linear models, we analyzed the relationships between local reliance or approval and sIRB of record approval times and (a) the regulatory option selected and (b) relying-site and process characteristics. Eighty-five sites received sIRB approval through 72 submissions (40% using local review, 46% using the SMART IRB agreement, 10% using an IRB authorization agreement, and 4% using a letter of support). Median time to establish a local reliance or study approval and sIRB approval were longest for sites using a SMART IRB agreement. Study-site region and the time of submission were significantly associated with local reliance or approval time, which averaged 129 and 107 days faster for Midwestern (p = 0.03) or Western (p = 0.02) sites, respectively, and 70 days slower for Northeastern sites (p = 0.42) compared with sites in the South, and 91 days slower when regulatory communication was initiated during or after February 2019 compared with before (p = 0.02). Similar relationships between sIRB approval time and region and time frame were observed; in addition, approval time was 103 days slower for sites affiliated with a research 1 (R1) university versus not (p = 0.02). Region of the country, time frame, and R1 university affiliation were associated with variations in study-site activation in a non-federally funded, multisite study.

Quantitative matching of crystal structures to experimental powder diffractograms.

The identification and classification of crystal structures is fundamental in materials science, as the crystal structure is an inherent factor of what gives solid materials their properties. Being able to identify the same crystallographic form from unique origins (e.g. different temperatures, pressures, or in silico-generated) is a complex challenge. While our previous work has focused on comparison of simulated powder diffractograms from known crystal structures, herein is presented the variable-cell experimental powder difference (VC-xPWDF) method to match collected powder diffractograms of unknown polymorphs to both experimental crystal structures from the Cambridge Structural Database and in silico-generated structures from the Control and Prediction of the Organic Solid State database. The VC-xPWDF method is shown to correctly identify the most similar crystal structure to both moderate and "low" quality experimental powder diffractograms for a set of 7 representative organic compounds. Features of the powder diffractograms that are more challenging for the VC-xPWDF method are discussed (i.e. preferred orientation), and comparison with the FIDEL method showcases the advantage of VC-xPWDF provided the experimental powder diffractogram can be indexed. The VC-xPWDF method should allow rapid identification of new polymorphs from solid-form screening studies, without requiring single-crystal analysis.

Many-body dispersion in model systems and the sensitivity of self-consistent screening.

London dispersion is a weak, attractive, intermolecular force that occurs due to interactions between instantaneous dipole moments. While individual dispersion contributions are small, they are the dominating attractive force between nonpolar species and determine many properties of interest. Standard semi-local and hybrid methods in density-functional theory do not account for dispersion contributions, so a correction such as the exchange-hole dipole moment (XDM) or many-body dispersion (MBD) models must be added. Recent literature has discussed the importance of many-body effects on dispersion, and attention has turned to which methods accurately capture them. By studying systems of interacting quantum harmonic oscillators from first principles, we directly compare computed dispersion coefficients and energies from XDM and MBD and also study the influence of changing oscillator frequency. Additionally, the 3-body energy contributions for both XDM, via the Axilrod-Teller-Muto term, and MBD, via a random-phase approximation formalism, are calculated and compared. Connections are made to interactions between noble gas atoms as well as to the methane and benzene dimers and to two layered materials, graphite and MoS2. While XDM and MBD give similar results for large separations, some variants of MBD are found to be susceptible to a polarization catastrophe at short range, and the MBD energy calculation is seen to fail in some chemical systems. Additionally, the self-consistent screening formalism used in MBD is shown to be surprisingly sensitive to the choice of input polarizabilities.