Simulation study of the electrical tunneling network conductivity of suspensions of hard spherocylinders

Using Monte Carlo simulations, we investigate the electrical conductivity of networks of hard rods with aspect ratios 10 and 20 as a function of the volume fraction for two tunneling conductance models. For a simple, orientationally independent tunneling model, we observe nonmonotonic behavior of the bulk conductivity as a function of volume fraction at the isotropic-nematic transition. However, this effect is lost if one allows for anisotropic tunneling. The relative conductivity enhancement increases exponentially with volume fraction in the nematic phase. Moreover, we observe that the orientational ordering of the rods in the nematic phase induces an anisotropy in the conductivity, i.e., enhanced values in the direction of the nematic director field. We also compute the mesh number of the Kirchhoff network, which turns out to be a simple alternative to the computationally expensive conductivity of large systems in order to get a qualitative estimate

Assessment of Disparities Associated with a Crisis Standards of Care Resource Allocation Algorithm for Patients in 2 US Hospitals during the COVID-19 Pandemic

Importance: Significant concern has been raised that crisis standards of care policies aimed at guiding resource allocation may be biased against people based on race/ethnicity. Objective: To evaluate whether unanticipated disparities by race or ethnicity arise from a single institution\u27s resource allocation policy. Design, Setting, and Participants: This cohort study included adults (aged ≥18 years) who were cared for on a coronavirus disease 2019 (COVID-19) ward or in a monitored unit requiring invasive or noninvasive ventilation or high-flow nasal cannula between May 26 and July 14, 2020, at 2 academic hospitals in Miami, Florida. Exposures: Race (ie, White, Black, Asian, multiracial) and ethnicity (ie, non-Hispanic, Hispanic). Main Outcomes and Measures: The primary outcome was based on a resource allocation priority score (range, 1-8, with 1 indicating highest and 8 indicating lowest priority) that was assigned daily based on both estimated short-term (using Sequential Organ Failure Assessment score) and longer-term (using comorbidities) mortality. There were 2 coprimary outcomes: maximum and minimum score for each patient over all eligible patient-days. Standard summary statistics were used to describe the cohort, and multivariable Poisson regression was used to identify associations of race and ethnicity with each outcome. Results: The cohort consisted of 5613 patient-days of data from 1127 patients (median [interquartile range {IQR}] age, 62.7 [51.7-73.7]; 607 [53.9%] men). Of these, 711 (63.1%) were White patients, 323 (28.7%) were Black patients, 8 (0.7%) were Asian patients, and 31 (2.8%) were multiracial patients; 480 (42.6%) were non-Hispanic patients, and 611 (54.2%) were Hispanic patients. The median (IQR) maximum priority score for the cohort was 3 (1-4); the median (IQR) minimum score was 2 (1-3). After adjustment, there was no association of race with maximum priority score using White patients as the reference group (Black patients: incidence rate ratio [IRR], 1.00; 95% CI, 0.89-1.12; Asian patients: IRR, 0.95; 95% CI. 0.62-1.45; multiracial patients: IRR, 0.93; 95% CI, 0.72-1.19) or of ethnicity using non-Hispanic patients as the reference group (Hispanic patients: IRR, 0.98; 95% CI, 0.88-1.10); similarly, no association was found with minimum score for race, again with White patients as the reference group (Black patients: IRR, 1.01; 95% CI, 0.90-1.14; Asian patients: IRR, 0.96; 95% CI, 0.62-1.49; multiracial patients: IRR, 0.81; 95% CI, 0.61-1.07) or ethnicity, again with non-Hispanic patients as the reference group (Hispanic patients: IRR, 1.00; 95% CI, 0.89-1.13). Conclusions and Relevance: In this cohort study of adult patients admitted to a COVID-19 unit at 2 US hospitals, there was no association of race or ethnicity with the priority score underpinning the resource allocation policy. Despite this finding, any policy to guide altered standards of care during a crisis should be monitored to ensure equitable distribution of resources

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

168 Prevalence and Severity of Sleep Disruption Amongst Asylum-Seekers in South Florida

Abstract Introduction While research suggests that asylum-seekers often present with a high level of medical and psychological needs, there is a dearth of research exploring sleep quality in this population, and, accordingly, the role that the sleep medicine community may be able to play in alleviating the suffering of this population. Therefore, this study aims to assess the prevalence of sleep disruption amongst asylum-seekers presenting to a South Florida clinic and to categorize these disruptions according to severity and type. Methods This is a cross-sectional study utilizing medical affidavits for asylum seekers in South Florida from 2018-2020 (n=54). Affidavits were reviewed for narrative descriptions of sleep quality and information from validated screeners regarding sleep; demographic information was also collected. Affidavits were excluded if they did not include itemized answers to screening questions. Results Out of 54 asylum-seekers (31% male, median age=34.5 years), 72.2% reported sleep disturbance. 38.9% reported nightmares, 66.7% reported insomnia of any type, and 29.6% reported severe insomnia. Asylum-seekers that screened positive for post-traumatic stress disorder (PTSD) were more likely to report ongoing sleep disturbance than asylum-seekers that screened negative for PTSD (p=.004). Sleep disturbance prevalence did not vary significantly by gender identity or country of origin. Conclusion This study reveals a high prevalence of sleep disruption amongst asylum-seekers in South Florida. The asylum-seekers in our study were more likely to experience insomnia than nightmares, but many experienced both; sleep disturbance was significantly associated with screening positive for PTSD. Our findings suggest that physicians working with asylum-seekers should ask about sleep quality and offer appropriate care. Directions for further research include investigating how poor sleep quality impacts the health and wellbeing of asylum-seekers. Support (if any) Non

Sorafenib treatment duration in desmoid tumors

11585 Background: Desmoid tumors are soft-tissue neoplasms, which, although unable to metastasize, can cause significant morbidity due to local invasion. Currently, the first-line approach is active surveillance. For tumors that progress during surveillance, systemic therapies can be used, including nirogacestat, sorafenib, pazopanib, and cytotoxic chemotherapy. However, their optimal duration is unknown. Here, we aim to assess the risk of treatment failure after discontinuing sorafenib before one year. Methods: We analyzed all patients with desmoid tumors treated with sorafenib at three academic centers from 01/01/2000-12/01/2021. We included patients who discontinued sorafenib not due to radiological or clinical progression and had documented no intention to start the next line of therapy at the time of discontinuation. The primary endpoint was 2-year treatment-free survival between patients who stopped sorafenib before and after 1 year. The secondary endpoint was the rate of toxic effects recorded according to the Common Terminology Criteria for Adverse Events during treatment. We calculated treatment-free survival using the Kaplan-Meier method with the Log-Rank Test to estimate the 95% confidence interval. All patients were censored at the 2-year mark. Fischer’s Exact T-test was performed to assess between-group differences. Results: 40 patients received sorafenib and discontinued it with no intention to start a next line of therapy. The main reasons for discontinuation were side effects (n=21, 52%) and physician-patient preference (n=10, 25%). 27 (67%)were women, and median age at diagnosis was 36.Regarding race and ethnicity,27 (47%)were White, 8 (20%)were Black, and 16 (40%) were Latino. The tumor was in the lower extremity in 10 (25%) cases, trunk in 3 (7%) cases, abdominal wall in 10 (25%), intra-abdominal in 5 (12%), upper extremity in 5 (12%) head-neck in 1 and breast in 1. 20 patients stopped treatment before one year and 20 after one year, with 7 and 3 patients requiring a next line of therapy in each group, respectively. The 2-year treatment-free survival was 60% (95% confidence interval [CI], 0.35 to 0.85) in the prior to 1-year group and 87.5% (95% CI, 0.71 to 1.0) in the post-1-year group (P = 0.046). The most frequently reported adverse events while on sorafenib were grade 1 or 2 events of palmar-plantar erythrodysesthesia (40%) and diarrhea (40%), with no difference between groups on therapy discontinuation due to side effects (p=0.1). Conclusions: Discontinuing sorafenib prior to 1 year was associated with a higher risk of requiring further therapy within the following two years. Still, most patients did not require additional therapy. This finding underscores the complexity of determining the optimal duration for sorafenib therapy, and multiple features should be considered, including side effects, symptom improvement, fertility planning, tumor cellularity (evaluated by T2 MRI signal), and physician-patient shared decision

Comparative effectiveness of systemic treatments in desmoid tumors.

e23534 Background: Many systemic treatment options are described for desmoid tumors, including hormonal therapies, non-steroidal anti-inflammatory drugs, cytotoxic chemotherapeutic agents, and most recently, tyrosine kinase inhibitors. Although many options are described, randomized data is scarce. The lack of comparative studies precludes a definitive sequence of the existing systemic treatments in the management of desmoid tumors. Here we retrospectively compare sorafenib with cytotoxic chemotherapy to generate objective data to guide treatment choice. Methods: We analyzed all patients with desmoid tumors treated with doxorubicin, dacarbazine, vinblastine, vinorelbine, methotrexate, or sorafenib in the first-line setting at a single center from 2000-2021. The primary endpoint was investigator-assessed progression-free survival. The secondary endpoint was the rate of toxic effects recorded accordingly to the Common Terminology Criteria for Adverse Events. We calculated progression-free survival (PFS) using the Kaplan-Meier method with Log-Rank Test to estimate the 95% confidence interval. Results: 79 patients ultimately received systemic therapies. Median follow-up was 5.6 years (0 to 7.9), 69% were women, and median age at diagnosis was 37 (range 5-77). Regarding race and ethnicity, 74% were White, 26%, Black and 45%, Latino. The tumor was in the lower extremity in 21 (27%) cases, trunk in 18 (23%) cases, abdominal wall in 13 (16%), intra-abdomen in 9 (11%), upper extremity in 7 (9%), head-neck in 7 (9%) and breast in 4 (5%). Surgery before systemic treatment was used in 20 (25%) patients. The regiments used were sorafenib (n = 32), doxorubicin with dacarbazine (n = 13), liposomal doxorubicin (n = 11), methotrexate with vinblastine (n = 11), methotrexate with vinorelbine (n = 8) and methotrexate monotherapy (n = 1). The 2-year progression-free survival rate was 80% (95% confidence interval [CI], 0.64 to 0.96) in the cytotoxic chemotherapy group and 66% (95% CI, 0.46 to 0.86) in the sorafenib group (P = 0.06). The most frequently reported adverse events on the cytotoxic group were grade 1 or 2 events of nausea (25%) and rash (15%), and on sorafenib were grade 1 or 2 events of palmar-plantar erythrodysesthesia (40%) and fatigue (25%). There were no treatment-related deaths reported. Conclusions: There was no statistical difference between the analyzed treatments, although there was a trend toward lower progression rates with cytotoxic therapy. </jats:p