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The objective of this study is to build a pulse combustion simulation model in order to determine the design parameters that influence the pulse combustor’s optimized performance. The Helmholtz valveless pulse combustor type is the simple design of pulse combustors. It has many advantages over conventional combustion, so it has been used in a variety of applications. There are many parameters that need to be studied in order to design this combustor type to achieve optimal performance. This research presents numerical and experimental investigations of pulse combustion. FLUENT software is used to conduct numerical simulations of the design parameters and pulse combustor performance. These simulations are then experimentally validated and confirmed to be accurately optimized in order to be applicable. The performance of the pulse combustor is studied for different inlet and tailpipe length and combustion chamber volume. This research accurately predicts how the frequency and pressure amplitude vary as the lengths of the inlet and tailpipe increase, as well as the combustion chamber volume.

Hospitals have demonstrated the benefits of both voluntary and mandatory bundled payments for joint replacement surgery. However, given generalizability and disparities concerns, it is critical to understand the availability of care through bundled payments to historically marginalized groups, such as racial and ethnic minorities and individuals with lower socioeconomic status (SES). This cross-sectional analysis of 3880 US communities evaluated the relationship between the proportion of Black and Hispanic individuals (minority share) or Medicare/Medicaid dual-eligible individuals (low SES share) and community-level participation in Bundled Payments for Care Improvement initiative (BPCI) (being a BPCI community) and Comprehensive Care for Joint Replacement (CJR) model (being a CJR community). An increase from the lowest to highest quartile of minority share was not associated with differences in the probability of being a BPCI community (3.5 percentage point [pp] difference, 95% confidence interval [CI] -1.2% to 8.3%

This paper presents a newly developed steady state core thermal hydraulic model (named SSTH-RR10 model) for upgrading the Egyptian first Research Reactor (ETRR-1), from its original power of 2 MWth to a higher level of 10 MWth, by considering different types of nuclear fuels. The SSTH-RR10 model is capable to predict and calculate, by means of a developed computer program, all the steady state thermal hydraulic parameters for the defined core configuration for each fuel type at 10 MWth. Three different fuel types were investigated: the reference fuel EK-10 rod type, the MTR plate type, and the IRT-4M ducted type. For each fuel type, the distribution of central fuel, clad, and coolant temperatures for average and hot channels of the core were predicted in the axial direction. Power distributions and pressure gradients were predicted as well. Moreover, the program calculates the safety limits and margins against the critical phenomena encountered such as the Onset of Nucleate Boiling (ONB), Departure from Nucleate Boiling (DNB), and the Onset of Flow Instability (OFI). Results of the SSTH-RR10 program for benchmarks of powers of 2 and 10 MWth are verified by comparing it with the published results of the International Atomic Energy Agency (IAEA), and those published for other programs such as PARET code, and very good agreement is found. The safety margins against ONB and DNB were evaluated in which the minimum DNB ratio was found to be about 3.1, which gives a sufficient margin against the DNB. The present work gives confidence in the model results and applications.

Clifford A Reilly,1 Makenna L Rice,2 Dylan J Parker,2 Philip P Goodney,3– 6 Jon D Lurie,3,4 Said A Ibrahim,7,8 Eric R Henderson2,4,6 1Larner College of Medicine, University of Vermont, Burlington, VT, USA; 2Department of Orthopaedic Surgery, Dartmouth Hitchcock Medical Center, Lebanon, NH, USA; 3The Dartmouth Institute for Health Policy and Clinical Practice, Dartmouth College, Hanover, NH, USA; 4Geisel School of Medicine, Dartmouth College, Hanover, NH, USA; 5Heart and Vascular Center, Dartmouth Hitchcock Medical Center, Lebanon, NH, USA; 6White River Junction VA Medical Center, US Department of Veterans Affairs, White River Junction, VT, USA; 7Zucker School of Medicine, Hofstra University/Northwell Health, Hempstead, NY, USA; 8Department of Medicine, Long Island Jewish Medical Center, New Hyde Park, NY, USACorrespondence: Makenna L Rice, Department of Orthopaedic Surgery, Dartmouth Hitchcock Medical Center, 1 Medical Center Dr, Rubin 592, Lebanon, NH, 03756, USA, Tel +1 831 247-1106, Fax +1 603 653-3581, Email Makenna.L.Rice@hitchcock.orgIntroduction: Decision aids are effective tools in facilitating patient-centered care and patient involvement in the decision-making process. Given unique barriers to providing patient-centered care for Veterans, implementation of decision aids may improve overall quality of care. We aimed to assess the acceptability and feasibility of video-based and pamphlet-based decision aid use in Veterans with knee osteoarthritis.Materials and Methods: Veterans considering treatment for knee osteoarthritis received either an online video-based aid, pamphlet-based aid, or both before their surgical consult. At their visit, patients completed written pre-visit and post-visit questionnaires. The pre-visit questionnaire included questions about the patient’s demographics, decision-making preferences, experiences using the assigned decision aids, and the Hip-Knee Decision Quality Instrument. The post-visit questionnaire assessed the patient’s overall experience with the decision-making process and how use of the decision aid influenced their discussion with the physician.Results: All 16 patients who received the pamphlet-based aid reviewed the decision aid before their visit, compared to only five of the 12 patients who received the video-based aid. Thirteen of 20 patients indicated that they preferred to share treatment decision-making with their physician. Seventeen of 20 patients believed they would feel comfortable questioning the treatment recommendation of their surgeon after decision aid use. Most patients reported a positive experience using their decision aid, regardless of modality, and found it easily comprehensible and useful in visit preparation. A preference for a pamphlet-based aid was expressed by the majority of patients.Conclusion: Veterans considering treatment for knee osteoarthritis are well prepared to engage in a patient-centered care experience. Most patients preferred sharing the decision-making process with their physician and felt comfortable questioning them about treatment recommendations. Decision aids helped Veterans feel more informed about their treatment options and improved engagement and discussion with their physician. Pamphlet-based aids were utilized more reliably than video-based aids.Keywords: patient-centered care, shared decision-making, decision aid, knee osteoarthritis, military service

BackgroundMagnetic resonance (MR) imaging is a powerful method for evaluating acute and chronic lesions of the stabilizing articular elements (volar plate and collateral ligaments) of the fingers and thumbs, the condition of tendons, the presence of a tear, the number of affected tendons, the extent of tendon retraction, and the presence of associated lesions. This study was done to clarify the value of magnetic resonance imaging (MRI) in assessment of trauma-related injuries of the tendons and ligaments of the fingers and subsequently positively affect the surgical decisions in such cases.ResultsThis study included 42 patients (33 males and 9 females) with a mean age of 35 years. All of them had history of trauma. Male affection was 78.5%, while females constituted only 21.5%, striking right-sided-hand affection (92.9%). The most affected finger was the thumb. The most common affected sites were extending from the metacarpophalangeal (MCP) till the proximal interphalangeal (PIP). The tendons were affected in 42.9%; meanwhile, ligamentous affection represented 57.2%. The flexor tendon tear represented by 28.6%%, while extensor tendon tear occurred in 14.3%. The study also showed that partial thickness tear is represented by 66.7%, while complete thickness tear occurred in about 33.3%. Bone marrow edema and post-traumatic tenosynovitis occurred in about 14% of cases.ConclusionsMagnetic resonance imaging is an essential technique to obtain a correct pre-surgical diagnosis. It is of utmost importance to possess an in-depth knowledge of finger radiological anatomy in detail, as well as the appearance of the different pathologic entities on MRI. It provides a great assessment of the tendons and ligaments tear by whether partial or complete, any associated marrow edema or bony fragment avulsion and the extent of retraction in cases of complete tear.

Total knee arthroplasty (TKA) is one of the most commonly performed, major elective surgeries in the USA. African American TKA patients on average experience worse clinical outcomes than whites, including lower improvements in patient-reported outcomes and higher rates of complications, hospital readmissions, and reoperations. The mechanisms leading to these racial health disparities are unclear, but likely involve patient, provider, healthcare system, and societal factors. Lower physical and mental health at baseline, lower social support, provider bias, lower rates of health insurance coverage, higher utilization of lower quality hospitals, and systemic racism may contribute to the inferior outcomes that African Americans experience. Limited evidence suggests that improving the quality of surgical care can offset these factors and lead to a reduction in outcome disparities.

Home dialysis rates for end-stage kidney disease (ESKD) treatment are substantially lower in the US than in other high-income countries, yet there is limited knowledge on how to increase these rates.To report results from the first year of a nationwide randomized clinical trial that provides financial incentives to ESKD facilities and managing clinicians to increase home dialysis rates.Results were analyzed from the first year of the End-Stage Renal Disease Treatment Choice (ETC) model, a multiyear, mandatory-participation randomized clinical trial designed and implemented by the US Center for MedicareMedicaid Innovation. Data were reported on Medicare patients with ESKD 66 years or older who initiated treatment with dialysis in 2021, with data collection through December 31, 2021; the study included all eligible ESKD facilities and managing clinicians. Eligible hospital referral regions (HRRs) were randomly assigned to the ETC (91 HRRs) or a control group (211 HRRs).The ESKD facilities and managing clinicians received financial incentives for home dialysis use.The primary outcome was the percentage of patients with ESKD who received any home dialysis during the first 90 days of treatment. Secondary outcomes included other measures of home dialysis and patient volume and characteristics.Among the 302 HRRs eligible for randomization, 18 621 eligible patients initiated dialysis treatment during the study period (mean [SD] age, 74.8 [1.05] years; 7856 women [42.1%]; 10 765 men [57.9%]; 859 Asian [5.2%], 3280 [17.7%] Black, 730 [4.3%] Hispanic, 239 North American Native, and 12 394 managing clinicians. The mean (SD) share of patients with any home dialysis during the first 90 days was 20.6% (7.8%) in the control group and was 0.12 percentage points higher (95% CI, -1.42 to 1.65 percentage points; P = .88) in the ETC group, a statistically nonsignificant difference. None of the secondary outcomes differed significantly between groups.The trial results found that in the first year of the US Center for MedicareMedicaid Innovation-designed ETC model, HRRs assigned to the model did not have statistically significantly different rates in home dialysis compared with control HRRs. This raises questions about the efficacy of the financial incentives provided, although further evaluation is needed, as the size of these incentives will increase in subsequent years.ClinicalTrials.gov Identifier: NCT05005572.

Objective To evaluate race and gender variations in complementary and alternative medicine (CAM) use for knee osteoarthritis (OA) (unadjusted and adjusted for demographic and clinical factors). Methods A secondary analysis of cross‐sectional data was conducted. The sample included Veterans Affairs patients 50 years of age or older with symptomatic knee OA. Current use of various CAM therapies was assessed at baseline. Logistic regression models were used to compare race and gender differences in the use of specific CAMs. Results The sample included 517 participants (52.2% identified as African American [AA]; 27.1% identified as female). After adjusting for demographic and clinical factors, AA participants, compared with white participants, were less likely to use joint supplements (odds ratio [OR]: 0.53; 95% confidence interval [CI], 0.31‐0.90]); yoga, tai chi, or pilates (OR: 0.39; 95% CI: 0.19‐0.77); and chiropractic care (OR: 0.51; 95% CI: 0.26‐1.00). However, they were more likely to participate in spiritual activities (OR: 2.02; 95% CI: 1.39‐2.94). Women, compared with men, were more likely to use herbs (OR: 2.42; 95% CI: 1.41‐4.14); yoga, tai chi, or pilates (OR: 2.09; 95% CI: 1.04‐4.19); acupuncture, acupressure, or massage (OR: 2.45; 95% CI: 1.28‐4.67); and spiritual activities (OR: 1.68; 95% CI: 1.09‐2.60). The interactive effects of race and gender were significant in the use of herbs (P = 0.008); yoga, tai chi, or pilates (P = 0.011); acupuncture, acupressure or massage (P = 0.038); and spiritual activities (P < 0.001). Conclusion There are race and gender differences in the use of various CAMs for OA. As benefits and limitations of CAM therapies vary, clinicians must be aware of these differences.

Background Primary care physicians (PCPs) are often gatekeepers to specialist care. This study assessed the relationship between PCP density and total knee (TKA) and total hip arthroplasty (THA) outcomes. Methods We obtained patient-level data from an institutional registry on patients undergoing elective primary TKA and THA for osteoarthritis, including Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function scores at baseline and 2 years. Using geocoding, we identified the number of PCPs in the patient’s census tract (communities). We used Augmented Inverse Probability Weighting and Cross-validated Targeted Minimum Loss-Based Estimation to compare provider density and outcomes adjusting for potential confounders. Results Our sample included 3606 TKA and 4295 THA cases. The median number of PCPs in each community was similar for both procedures: TKA 2 (interquartile range 1, 6) and for THA 2 (interquartile range 1, 7). Baseline and 2-year follow-up WOMAC pain, function, and stiffness scores were not statistically significantly different comparing communities with more than median number of PCPs to those with less than median number of PCPs. In sensitivity analyses, adding 1 PCP to a community with zero PCPs would not have statistically significantly improved baseline or 2-year follow-up WOMAC pain, function, and stiffness scores. Conclusions In this sample of patients who underwent elective TKA or THA for osteoarthritis, we found no statistically significant association between PCP density and pain, function, or stiffness outcomes at baseline or 2 years. Further studies should examine what other provider factors affect access and outcomes in THA and TKA.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has disproportionately affected socially disadvantaged populations. Whether disparities in COVID-19 incidence related to race/ethnicity and socioeconomic factors exist in the hemodialysis population is unknown. METHODS: Our study involved patients receiving in-center hemodialysis in New York City. We used a validated index of neighborhood social vulnerability, the Social Vulnerability Index (SVI), which comprises 15 census tract-level indicators organized into four themes: socioeconomic status, household composition and disability, minority status and language, and housing type and transportation. We examined the association of race/ethnicity and the SVI with symptomatic COVID-19 between March 1, 2020 and August 3, 2020. COVID-19 cases were ascertained using PCR testing. We performed multivariable logistic regression to adjust for demographics, individual-level social factors, dialysis-related medical history, and dialysis facility factors. RESULTS: Of the 1378 patients on hemodialysis in the study, 247 (17.9%) developed symptomatic COVID-19. In adjusted analyses, non-Hispanic Black and Hispanic patients had significantly increased odds of COVID-19 compared with non-Hispanic White patients. Census tract-level overall SVI, modeled continuously or in quintiles, was not associated with COVID-19 in unadjusted or adjusted analyses. Among non-Hispanic White patients, the socioeconomic status SVI theme, the minority status and language SVI theme, and housing crowding were significantly associated with COVID-19 in unadjusted analyses. CONCLUSIONS: Among patients on hemodialysis in New York City, there were substantial racial/ethnic disparities in COVID-19 incidence not explained by neighborhood-level social vulnerability. Neighborhood-level socioeconomic status, minority status and language, and housing crowding were positively associated with acquiring COVID-19 among non-Hispanic Whites. Our findings suggest that socially vulnerable patients on dialysis face disparate COVID-19-related exposures, requiring targeted risk-mitigation strategies.

To assess the impact of sociodemographic factors on primary treatment choice (surgery vs radiotherapy) in patients with human papillomavirus-associated (HPV+) oropharyngeal squamous cell carcinoma (OPSCC).Retrospective analysis of the National Cancer Database.Data from1500 Commission on Cancer institutions (academic and community) via the National Cancer Database.Our sample consists of patients diagnosed with HPV+ OPSCC from 2010 to 2015. The primary outcome of interest was initial treatment modality: surgery vs radiation. We performed multivariable logistic models to assess the relationship between treatment choice and sociodemographic factors, including sex, race, treatment facility, and insurance status.Of the 16,043 patients identified, 5894 (36.7%) underwent primary surgery while 10,149 (63.3%) received primary radiotherapy. Black patients were less likely than White patients to receive primary surgery (odds ratio [OR], 0.80; 95% CI, 0.66-0.96). When compared with privately insured patients, those who were uninsured or on Medicaid or Medicare were also less likely to receive primary surgery (OR, 0.70 [95% CI, 0.56-0.86]; OR, 0.77 [95% CI, 0.65-0.91]; OR, 0.85 [95% CI, 0.75-0.96], respectively). Patients receiving treatment at an academic/research cancer program were more likely to undergo primary surgery than those treated at comprehensive community cancer programs (OR, 1.33; 95% CI, 1.14-1.56).In this large sample of patients with HPV+ OPSCC, race and insurance status affect primary treatment choice. Specifically, Black and nonprivately insured patients are less likely to receive primary surgery as compared with White or privately insured patients. Our findings illuminate potential disparities in HPV+ OPSCC treatment.

BACKGROUND Due to inherent impact on quality of life, metastatic head and neck cancer patients are well-suited to benefit from palliative care (PC). Our objective was to examine factors that shape PC utilization and implications for overall survival in stage IVc head and neck cancer patients. METHODS A retrospective study of patients with stage IVc head and neck cancer in the National Cancer Database from 2004 and 2015 was conducted. RESULTS 7794 cases met inclusion criteria, of which 19.3% received PC. PC use was associated with more recent years of diagnosis, Northeast facility geography, and non-private insurances (p

Introduction:On September 20, 2017, Hurricane Maria, a Category 4 hurricane, swept across Puerto Rico (PR), wreaking devastation to PR’s power, water, and health care infrastructure. To address the imminent humanitarian crisis, the US government mobilized Federal Medical Shelters (FMS) to serve the needs of hurricane victims. This study’s objective was to provide a description of the patients seeking emergency care at FMS and the changes in their needs over time.Methods:This retrospective, cross-sectional study included all patients presenting to the FMS Manatí from October 6, two weeks after Hurricane Maria’s landfall, to November 2, 2017. Categories were created to catalogue the nature of new acute medical issues by patients presenting to the Shelter. Descriptive, graphical analyses were performed to assess changes to presenting complaints over time, and by age groups defined as infant (age ≤1 years), child (1 year < age ≤10 years), adolescent (10 years < age ≤ 25 years), and adult (age > 25 years).Results:Over the 30-day period, 5,268 patients were seen in the FMS seeking medical care (average 188.1 patients per day), spending less than five hours in the facility. The distribution of patients’ age was bimodal: the first peak at one year and the second at age 50. The most common patient complaint was infection (38.8%), then musculoskeletal (MSK) complaints (11.8%) and management of chronic medical conditions (11.8%). The proportion of patients presenting with chronic disease complaints declined over the course of the period of observation (21.4% on Day 4 to 8.0% on Day 30) while the proportion of patients presenting with infection increased (31.0% on Day 4 to 48.6% on Day 30). Infection complaints were highest in all age groups, but most in infxants (80.2%), while MSK and chronic disease complaints were highest in adults (14.9% and 14.9%, respectively).Conclusion:Infection treatment and chronic disease management were important medical needs facing patients seeking care at FMS Manatí after Hurricane Maria. These findings suggest that basic needs related to sanitation and shelter remained important weeks after the hurricane, and a focus on access to medications, infection control, and injury prevention/management after a disaster needs to be prioritized during disaster response.

BACKGROUND: We sought to examine bilateral total knee arthroplasty (BTKA) vs unilateral TKA (UTKA) utilization and in-hospital complications comparing African Americans (AAs) and Whites. METHODS: In this retrospective analysis of patients ≥50 years who underwent elective primary TKA, National Inpatient Sample - Healthcare Cost and Utilization Project database (2007–2016) was used. We computed differences in temporal trends in utilization and major in-hospital complication rates of BTKA vs UTKA comparing AAs and Whites. We performed multivariable logistic regression models to assess racial differences in trends adjusting for individual-, hospital- and community-level variables. Discharge weights were used to enable nationwide estimates. We used multiple imputation procedures to impute values for 12% missing race information. RESULTS: An estimated 276,194 BTKA and 5,528,429 UTKA were performed in the US. The proportion of BTKA amongst all TKAs declined, and AAs were significantly less likely to undergo BTKA compared to Whites throughout the study period (trend P = 0.01). In-hospital complication rates for UTKA were higher in AAs compared to Whites throughout the study period (trend P < .0001). However, for BTKA, the in-hospital complication rates varied between Whites and AAs throughout the study period (trend P = 0.09). CONCLUSION: In this nationwide sample of patients from 2007–2016 who underwent total knee arthroplasty, the utilization of BKTA was higher in Whites compared to AAs. On the other hand, while AAs have consistently higher in-hospital complication rates in UTKA over the time period, this pattern was not consistent for BTKA.

Objective The objective of this study was to evaluate how patient knowledge and beliefs regarding nonsteroidal anti‐inflammatory drugs (NSAIDs) may influence the use of NSAIDs for osteoarthritis (OA). Methods Surveys of 334 adults with knee and/or hip OA were analyzed in this cross‐sectional study. Familiarity with and perceptions of benefits/risks of NSAID use were measured to assess associations with the use of prescription and nonprescription oral NSAIDs. Multinomial logistic regression models were adjusted for sociodemographic and clinical variables. Results In this sample, 35.9% and 35.6% reported use of oral prescription and nonprescription‐only NSAIDs, respectively. Hispanic participants, compared with non‐Hispanic White participants, had lower perceived benefit (P = 0.005) and risk (P = 0.001) of prescription NSAIDs. The following were associated with prescription NSAID use instead of no NSAID use: having family/friends who used prescription (relative risk ratio [RRR] 3.91; 95% confidence interval [CI] 2.05‐7.47) and over‐the‐counter (OTC) (RRR 3.10; 95% CI 1.65‐5.83) NSAIDs for OA, understanding the consequences of using both prescription (RRR 3.50; 95% CI 1.79‐6.86) and OTC (RRR 2.80; 95% CI 1.39‐5.65) NSAIDs, higher perceived benefit of both prescription (RRR 2.51; 95% CI 1.71‐3.66) and OTC (RRR 1.44; 95% CI 1.01‐2.06) NSAIDs, and lower perceived risk of both types of NSAIDs (prescription: RRR 0.63 [95% CI 0.46‐0.87]; OTC: RRR 0.53 [95% CI 0.37‐0.75]). Similar results were found when we assessed the relationship between these variables and OTC NSAID use versus no oral NSAID use. Conclusion Adults with knee and/or hip OA were more likely to use NSAIDs if they were more familiar with, had an increased perceived benefit of, and had a decreased perceived risk of these drugs. Patients’ perceptions and beliefs about NSAIDs should be evaluated when considering them for treatment.