Estimating the Allocation of the Economic Value Generated by Utilization of All-Oral Direct-Acting Antivirals for Hepatitis C in the United States, 2015-2019.

OBJECTIVES: Between 2013-2019, several all-oral direct-acting antivirals (DAAs) were launched with the potential to cure patients with hepatitis C virus (HCV). They generated economic value in terms of the health gains for patients and cost-savings for the US healthcare system. We estimated the share of this value allocated to four manufacturers vs society. METHODS: For 2015-2019, we estimated the incremental impact of DAAs on HCV health outcomes and costs. We used the CDAF Polaris Observatory database to estimate utilization. Per-patient projections of lifetime quality-adjusted life-years (QALYs) gained and medical costs avoided were based on a standard 9-state HCV disease-progression model for DAA treatment vs alternatives. Annual QALY gains were valued at $114,000 per QALY. Outcomes and costs were discounted at 3%. Estimated revenues were based on reported sales. RESULTS: An estimated 1,080,000 patients received DAAs: 81.5% would not have received the pre-DAA standard of care. On average, these patients were projected to gain 4.4 QALYs and save $104,400 in lifetime healthcare costs, generating $531.8 billion in value. Those who would have received treatment gained 1.7 QALYs and saved $41,500 in lifetime costs, generating $47.4 billion in economic value. As treatment costs fell nearly 75%, the four manufacturers reported $37.4 billion from DAA sales-an allocation of 6.5% of the total value. CONCLUSIONS: The great majority (∼90%) of the economic value of curing HCV with DAAs were health benefits to patients and net cost-savings to society. DAA manufacturers received a minority share (6.5%) of the aggregate economic value generated.

Outcomes in ovarian Sertoli-Leydig cell tumor: A report from the International Pleuropulmonary Blastoma/DICER1 and Ovarian and Testicular Stromal Tumor Registries.

OBJECTIVE: Sertoli-Leydig cell tumors (SLCTs) are rare sex cord-stromal tumors, representing <0.5% of all ovarian tumors. We sought to describe prognostic factors, treatment and outcomes for individuals with ovarian SLCT. METHODS: Individuals with SLCT were enrolled in the International Pleuropulmonary Blastoma/DICER1 Registry and/or the International Ovarian and Testicular Stromal Tumor Registry. Medical records were systematically abstracted, and pathology was centrally reviewed when available. RESULTS: In total, 191 participants with ovarian SLCT enrolled, with most (92%, 175/191) presenting with FIGO stage I disease. Germline DICER1 results were available for 156 patients; of these 58% had a pathogenic or likely pathogenic germline variant. Somatic (tumor) DICER1 testing showed RNase IIIb hotspot variants in 97% (88/91) of intermediately and poorly differentiated tumors. Adjuvant chemotherapy was administered in 40% (77/191) of cases, and among these, nearly all patients received platinum-based regimens (95%, 73/77), and 30% (23/77) received regimens that included an alkylating agent. Three-year recurrence-free survival for patients with stage IA tumors was 93.6% (95% CI: 88.2-99.3%) compared to 67.1% (95% CI: 55.2-81.6%) for all stage IC and 60.6% (95% CI: 40.3-91.0%) for stage II-IV (p < .001) tumors. Among patients with FIGO stage I tumors, those with mesenchymal heterologous elements treated with surgery alone were at higher risk for recurrence (HR: 74.18, 95% CI: 17.99-305.85). CONCLUSION: Most individuals with SLCT fare well, though specific risk factors such as mesenchymal heterologous elements are associated with poor prognosis. We also highlight the role of DICER1 surveillance in early detection of SLCT, facilitating stage IA resection.

Efficacy and Safety of Botulinum Toxin Type A for the Prevention of Postoperative Atrial Fibrillation.

BACKGROUND: Postoperative atrial fibrillation (POAF) is associated with increased morbidity and mortality. Epicardial injection of botulinum toxin may suppress POAF. OBJECTIVES: This study sought to assess the safety and efficacy of AGN-151607 for the prevention of POAF after cardiac surgery. METHODS: This phase 2, randomized, placebo-controlled trial assessed the safety and efficacy of AGN-151607, 125 U and 250 U vs placebo (1:1:1), for the prevention of POAF after cardiac surgery. Randomization was stratified by age (<65, ≥65 years) and type of surgery (nonvalvular/valve surgery). The primary endpoint was the occurrence of continuous AF ≥30 seconds. RESULTS: Among 312 modified intention-to-treat participants (placebo, n = 102; 125 U, n = 104; and 250 U, n = 106), the mean age was 66.9 ± 6.8 years; 17% were female; and 64% had coronary artery bypass graft (CABG) only, 12% had CABG + valve, and 24% had valve surgery. The primary endpoint occurred in 46.1% of the placebo group, 36.5% of the 125-U group (relative risk [RR] vs placebo: 0.80; 95% CI: 0.58-1.10; P = 0.16), and 47.2% of the 250-U group (RR vs placebo: 1.04; 95% CI: 0.79-1.37; P = 0.78). The primary endpoint was reduced in the 125-U group in those ≥65 years (RR: 0.64; 95% CI: 0.43-0.94; P = 0.02) with a greater reduction in CABG-only participants ≥65 years (RR: 0.49; 95% CI: 0.27-0.87; P = 0.01). Rehospitalization and rates of adverse events were similar across the 3 groups. CONCLUSIONS: There were no significant differences in the rate of POAF with either dose compared with placebo; however, there was a lower rate of POAF in participants ≥65 years undergoing CABG only and receiving 125 U of AGN-151607. These hypothesis-generating findings require investigation in a larger, adequately powered randomized clinical trial. (Botulinum Toxin Type A [AGN-151607] for the Prevention of Post-operative Atrial Fibrillation in Adult Participants Undergoing Open-chest Cardiac Surgery [NOVA]; NCT03779841); A Phase 2, Multi-Center, Randomized, Double-Blind, Placebo-Controlled, Dose Ranging Study to Evaluate the Efficacy and Safety of Botulinum Toxin Type A [AGN 151607] Injections into the Epicardial Fat Pads to Prevent Post-Operative Atrial Fibrillation in Patients Undergoing Open-Chest Cardiac Surgery; 2017-004399-68).

Impact of Delirium Onset and Duration on Mortality in Patients With Cancer Admitted to the ICU.

BACKGROUND: Little is known on the effects of delirium onset and duration on outcome in critically ill patients with cancer. OBJECTIVES: To determine the impact of delirium onset and duration on intensive care unit (ICU) and hospital mortality and length of stay (LOS) in patients with cancer. METHODS: Of the 915 ICU patients admitted in 2018, 371 were included for analysis after excluding for terminal disease, <24-h ICU stay, lack of active cancer and delirium. Delirium was defined as early if onset was within 2 days of ICU admission, late if onset was on day 3 or later, short if duration was 2 days or less, and long if duration was 3 days or longer. Patients were placed into 4 combination groups: early-short, early-long, late-short, and late-long delirium. Multivariate analysis controlling for sex, age, metastatic disease, and predelirium hospital LOS was performed to determine ICU and hospital mortality and LOS. Exploratory analysis of long-term survival was also performed. Restricted cubic splines were performed to confirm the use of 2 days to distinguish between early versus late onset and short versus long duration. RESULTS: A total of 32.9% (n = 122) patients had early-short, 39.1% (n = 145) early-long, 16.2% (n = 60) late-short, and 11.9% (n = 44) late-long delirium. Late-long delirium was independently associated with increased ICU (OR 4.45, CI 1.92-10.30; P < .001) and hospital (OR 2.91, CI 1.37-6.19; P = .005) mortality and longer ICU (OR 1.97, CI 1.58-2.47; P < .001) LOS compared to early-short delirium. Early delirium had better overall survival at 18 months than late delirium. Long-term survival further improved when delirium duration was 2 days or less. Prediction heatmaps confirm the use of a 2-day cutoff. CONCLUSION: Late delirium, especially with long duration, significantly worsens outcome in ICU patients with cancer and should be considered a harbinger of poor overall condition.

'If you build it, they will come to the wrong door: evaluating patient and caregiver-initiated ethics consultations via a patient portal'.

OBJECTIVES: Memorial Sloan Kettering Cancer Center (MSK) sought to empower patients and caregivers to be more proactive in requesting ethics consultations. METHODS: Functionality was developed on MSK's electronic patient portal that allowed patients and/or caregivers to request ethics consultations. The Ethics Consultation Service (ECS) responded to all requests, which were documented and analysed. RESULTS: Of the 74 requests made through the portal, only one fell under the purview of the ECS. The others were primarily requests for assistance with coordinating clinical care, hospital resources or frustrations with the hospital or clinical team. DISCUSSION: To better empower patients and caregivers to engage Ethics, healthcare organisations and ECSs must first provide them with accessible, understandable and iterative educational resources. CONCLUSION: After 19.5 months, the 'Request Ethics Consultation' functionality on the patient portal was suspended. Developing resources on the role of Ethics for our patients and caregivers remains a priority.

The evolving value assessment of cancer therapies: Results from a modified Delphi study.

The move toward early detection and treatment of cancer presents challenges for value assessment using traditional endpoints. Current cancer management rarely considers the full economic and societal benefits of therapies. Our study used a modified Delphi process to develop principles for defining and assessing value of cancer therapies that aligns with the current trajectory of oncology research and reflects broader notions of value. 24 experts participated in consensus-building activities across 5 months (16 took part in structured interactions, including a survey, plenary sessions, interviews, and off-line discussions, while 8 participated in interviews). Discussion focused on: 1) which oncology-relevant endpoints should be used for assessing treatments for early-stage cancer and access decisions for early-stage treatments, and 2) the importance of additional value components and how these can be integrated in value assessments. The expert group reached consensus on 4 principles in relation to the first area (consider oncology-relevant endpoints other than overall survival; build evidence for endpoints that provide earlier indication of efficacy; develop evidence for the next generation of predictive measures; use managed entry agreements supported by ongoing evidence collection to address decision-maker evidence needs) and 3 principles in relation to the second (routinely use patient reported outcomes in value assessments; assess broad economic impact of new medicines; consider other value aspects of relevance to patients and society).

Consensus statement-graft treatment in cardiovascular bypass graft surgery.

Coronary artery bypass grafting (CABG) is and continues to be the preferred revascularization strategy in patients with multivessel disease. Graft selection has been shown to influence the outcomes following CABG. During the last almost 60 years saphenous vein grafts (SVG) together with the internal mammary artery have become the standard of care for patients undergoing CABG surgery. While there is little doubt about the benefits, the patency rates are constantly under debate. Despite its acknowledged limitations in terms of long-term patency due to intimal hyperplasia, the saphenous vein is still the most often used graft. Although reendothelialization occurs early postoperatively, the process of intimal hyperplasia remains irreversible. This is due in part to the persistence of high shear forces, the chronic localized inflammatory response, and the partial dysfunctionality of the regenerated endothelium. "No-Touch" harvesting techniques, specific storage solutions, pressure controlled graft flushing and external stenting are important and established methods aiming to overcome the process of intimal hyperplasia at different time levels. Still despite the known evidence these methods are not standard everywhere. The use of arterial grafts is another strategy to address the inferior SVG patency rates and to perform CABG with total arterial revascularization. Composite grafting, pharmacological agents as well as latest minimal invasive techniques aim in the same direction. To give guide and set standards all graft related topics for CABG are presented in this expert opinion document on graft treatment.

New Vaccine Platforms-Novel Dimensions of Economic and Societal Value and Their Measurement.

The COVID-19 pandemic's dramatic impact has been a vivid reminder that vaccines-especially in the context of infectious respiratory viruses-provide enormous societal value, well beyond the healthcare system perspective which anchors most Health Technology Assessment (HTA) and National Immunization Technical Advisory Group (NITAG) evaluation frameworks. Furthermore, the development of modified ribonucleic acid-based (mRNA-based) and nanoparticle vaccine technologies has brought into focus several new value drivers previously absent from the discourse on vaccines as public health interventions such as increased vaccine adaptation capabilities, the improved ability to develop combination vaccines, and more efficient vaccine manufacturing and production processes. We review these novel value dimensions and discuss how they might be measured and incorporated within existing value frameworks using existing methods. To realize the full potential of next-generation vaccine platforms and ensure their widespread availability across populations and health systems, it is important that value frameworks utilized by HTAs and NITAGs properly reflect the full range of benefits for population health and well-being and cost efficiencies that these new vaccines platforms provide.

In silico parametric analysis of femoro-jugular venovenous ECMO and return cannula dynamics: In silico analysis of femoro-jugular VV ECMO.

BACKGROUND: Increasingly, computational fluid dynamics (CFD) is helping explore the impact of variables like: cannula design/size/position/flow rate and patient physiology on venovenous (VV) extracorporeal membrane oxygenation (ECMO). Here we use a CFD model to determine what role cardiac output (CO) plays and to analyse return cannula dynamics. METHODS: Using a patient-averaged model of the right atrium and venae cava, we virtually inserted a 19Fr return cannula and a 25Fr drainage cannula. Running large eddy simulations, we assessed cardiac output at: 3.5-6.5 L/min and ECMO flow rate at: 2-6 L/min. We analysed recirculation fraction (Rf), time-averaged wall shear stress (TAWSS), pressure, velocity, and turbulent kinetic energy (TKE) and extracorporeal flow fraction (EFF = ECMO flow rate/CO). RESULTS: Increased ECMO flow rate and decreased CO (high EFF) led to increased Rf (R = 0.98, log fit). Negative pressures developed in the venae cavae at low CO and high ECMO flow (high CR). Mean return cannula TAWSS was >10 Pa for all ECMO flow rates, with majority of the flow exiting the tip (94.0-95.8 %). CONCLUSIONS: Our results underpin the strong impact of CO on VV ECMO. A simple metric like EFF, once supported by clinical data, might help predict Rf for a patient at a given ECMO flow rate. The return cannula imparts high shear stresses on the blood, largely a result of the internal diameter.

Characterizing continuous positive airway pressure (CPAP) Belly Syndrome in preterm infants in the neonatal intensive care unit (NICU).

OBJECTIVE: Reproducibly define CPAP Belly Syndrome (CBS) in preterm infants and describe associated demographics, mechanical factors, and outcomes. STUDY DESIGN: A retrospective case-control study was conducted in infants <32 weeks gestation in the Stanford Children's NICU from January 1, 2020 to December 31, 2021. CBS was radiographically defined by a pediatric radiologist. Data analysis included descriptive statistics and comparator tests. RESULTS: Analysis included 41 infants with CBS and 69 infants without. CBS was associated with younger gestational age (median 27.7 vs 30 weeks, p < 0.001) and lower birthweight (median 1.00 vs 1.31 kg, p < 0.001). Infants with CBS were more likely to receive bilevel respiratory support and higher positive end expiratory pressure. Infants with CBS took longer to advance enteral feeds (median 10 vs 7 days, p = 0.003) and were exposed to more abdominal radiographs. CONCLUSIONS: Future CBS therapies should target small infants, prevent air entry from above, and aim to reduce time to full enteral feeds and radiographic exposure.

Prevalence of lung cysts in adolescents and adults with a germline DICER1 pathogenic/likely pathogenic variant: a report from the National Institutes of Health and International Pleuropulmonary Blastoma/DICER1 Registry.

BACKGROUND: Pleuropulmonary blastoma (PPB), the hallmark tumour associated with DICER1-related tumour predisposition, is characterised by an age-related progression from a cystic lesion (type I) to a high-grade sarcoma with mixed cystic and solid features (type II) or purely solid lesion (type III). Not all cystic PPBs progress; type Ir (regressed), hypothesised to represent regressed or non-progressed type I PPB, is an air-filled, cystic lesion lacking a primitive sarcomatous component. This study aims to evaluate the prevalence of non-progressed lung cysts detected by CT scan in adolescents and adults with germline DICER1 pathogenic/likely pathogenic (P/LP) variants. METHODS: Individuals were enrolled in the National Cancer Institute Natural History of DICER1 Syndrome study, the International PPB/DICER1 Registry and/or the International Ovarian and Testicular Stromal Tumor Registry. Individuals with a germline DICER1 P/LP variant with first chest CT at 12 years of age or older were selected for this analysis. RESULTS: In the combined databases, 110 individuals with a germline DICER1 P/LP variant who underwent first chest CT at or after the age of 12 were identified. Cystic lung lesions were identified in 38% (42/110) with a total of 72 cystic lesions detected. No demographic differences were noted between those with lung cysts and those without lung cysts. Five cysts were resected with four centrally reviewed as type Ir PPB. CONCLUSION: Lung cysts are common in adolescents and adults with germline DICER1 variation. Further study is needed to understand the mechanism of non-progression or regression of lung cysts in childhood to guide judicious intervention.

The interaction between heterochrony and mechanical forces as main driver of floral evolution.

Heterochrony acts as a fundamental process affecting the early development of organisms in creating a subtle shift in the timing of initiation or the duration of a developmental process. In flowers this process is linked with mechanical forces that cause changes in the interaction of neighbouring floral organs by altering the timing and rate of initiation of organs. Heterochrony leads to a delay or acceleration of the development of neighbouring primordia, inducing a change in the morphospace of the flowers. As changes in the timing of development may affect organs differently at different stages of development, these shifts eventually lead to major morphological changes such as altered organ positions, fusions, or organ reductions with profound consequences for floral evolution and the diversification of flowers. By concentrating on early developmental stages in flowers it is possible to understand how heterochrony is responsible for shifts in organ position and the establishment of a novel floral Bauplan. However, it remains difficult to separate heterochrony as a process from pattern, as both are intimately linked. Therefore it is essential to connect different patterns in flowers through the process of developmental change.Examples illustrating the importance of heterochronic shifts affecting different organs of the flower are presented and discussed. These cover the transition from inflorescence to flower through the interaction of bracts and bracteoles, the pressure exercised by the perianth on the androecium and gynoecium, the inversed influence of stamens on petals, and the centrifugal influence of carpels on the androecium. Different processes are explored, including the occurrence of obdiplostemony, the onset of common primordia, variable carpel positions, and organ reduction and loss.

Incorporating Real Option Value in Valuing Innovation: A Way Forward.

BACKGROUND: Considerable progress has been made in defining and measuring the real option value (ROV) of medical technologies. However, questions remain on how to estimate (1) ROV outside of life-extending oncology interventions; (2) the impact of ROV on costs and cost effectiveness; and (3) potential interactions between ROV and other elements of value. METHODS: We developed a 'minimal modeling' approach for estimating the size of ROV that does not require constructing a full, formal cost-effectiveness model. We proposed a qualitative approach to assessing the level of uncertainty in the ROV estimate. We examined the potential impact of ROV on the incremental cost-effectiveness ratio as well as on the potential interactions between ROV and other elements of value. Lastly, we developed and presented a 15-item checklist for reporting ROV in value assessment. RESULTS: The minimal modeling approach uses estimates on the efficacy of current treatment and potential future innovation, as well as success rate and length of new treatment development, and can be applied to all types of ROV across disease areas. ROV may interact with the conventional value, value of hope, productivity effects, and insurance value. The impact of ROV on cost effectiveness can be evaluated via threshold analysis. CONCLUSION: The minimal modeling approach and the checklist developed in this paper simplifies and standardizes the estimation and reporting of ROV in value assessment. Systematically including and reporting ROV in value assessment will minimize bias and improve transparency, which will help improve the credibility of ROV research and acceptance by stakeholders.

Evidence Synthesis and Linkage for Modelling the Cost-Effectiveness of Diagnostic Tests: Preliminary Good Practice Recommendations.

OBJECTIVES: To develop preliminary good practice recommendations for synthesising and linking evidence of treatment effectiveness when modelling the cost-effectiveness of diagnostic tests. METHODS: We conducted a targeted review of guidance from key Health Technology Assessment (HTA) bodies to summarise current recommendations on synthesis and linkage of treatment effectiveness evidence within economic evaluations of diagnostic tests. We then focused on a specific case study, the cost-effectiveness of troponin for the diagnosis of myocardial infarction, and reviewed the approach taken to synthesise and link treatment effectiveness evidence in different modelling studies. RESULTS: The Australian and UK HTA bodies provided advice for synthesising and linking treatment effectiveness in diagnostic models, acknowledging that linking test results to treatment options and their outcomes is common. Across all reviewed models for the case study, uniform test-directed treatment decision making was assumed, i.e., all those who tested positive were treated. Treatment outcome data from a variety of sources, including expert opinion, were utilised for linked clinical outcomes. Preliminary good practice recommendations for data identification, integration and description are proposed. CONCLUSION: Modelling the cost-effectiveness of diagnostic tests poses unique challenges in linking evidence on test accuracy to treatment effectiveness data to understand how a test impacts patient outcomes and costs. Upfront consideration of how a test and its results will likely be incorporated into patient diagnostic pathways is key to exploring the optimal design of such models. We propose some preliminary good practice recommendations to improve the quality of cost-effectiveness evaluations of diagnostics tests going forward.

Unveiling chemical responses in the kombucha-based fermentation of black tea, banana flower, and grape juice: LC-ESIMS, GNPS, MS-DIAL, and MS-FINDER-assisted chemical characterization.

The lack of studies evaluating the chemical responses of kombucha microorganisms when exposed to plants is notable in the literature. Therefore, this work investigates the chemical behaviour of 7-, 14- and 21 day-fermentation of kombucha derived from three extracts obtained from banana inflorescence, black tea, and grape juice. After the acquisition of UPLC-ESI-MS data, GNPS molecular networking, MS-Dial, and MS-Finder were used to chemically characterize the samples. The microbial chemical responses were enzymatic hydrolysis, oxidation, and biosynthesis. The biosynthesis was different among the kombucha samples. In fermented black tea, gallic and dihydrosinapic acids were found as hydrolysis products alongside a sugar-derived product namely 7-(α-D-glucopyranosyloxy)-2,3,4,5,6-pentahydroxyheptanoic acid. The sphingolipids, safingol and cedefingol alongside capryloyl glycine and palmitoyl proline were identified. In fermented grapes, sugar degradation and chemical transformation products were detected together with three cell membrane hopanoids characterized as hydroxybacteriohopanetetrol cyclitol ether, (Δ6 or Δ11)-hydroxybacteriohopanetetrol cyclitol ether, and methyl (Δ6 or Δ11)-hydroxybacteriohopanetetrol cyclitol. The fermented banana blossom showed the presence of methyl (Δ6 or Δ11)-hydroxybacteriohopanetetrol cyclitol together with sphingofungin B, sphinganine and other fatty acid derivatives. Parts of these samples were tested for their inhibition against α-glucosidase and their antioxidant effects. Except for the 14-day fermented extracts, other black tea extracts showed significant inhibition of α-glucosidase ranging from 42.5 to 42.8%. A 14-day fermented extract of the banana blossom infusion showed an inhibition of 29.1%, while grape samples were less active than acarbose. The 21-day fermented black tea extract showed moderate antioxidant properties on a DPPH-based model with an EC50 of 5.29 ± 0.10 µg mL-1, while the other extracts were weakly active (EC50 between 80.76 and 168.12 µg mL-1).

Evaluating Policies of Expanding Versus Restricting First-Line Treatment Choices: A Cost-Effectiveness Analysis Framework.

OBJECTIVES: Healthcare payers often implement coverage policies that restrict the utilization of costly new first-line treatments. Cost-effectiveness analysis can be conducted to inform these decisions by comparing the new treatment with an existing one. However, this approach may overlook important factors such as treatment effect heterogeneity and endogenous treatment selection, policy implementation costs, and diverse patient preferences across multiple treatment options. We aimed to develop a cost-effectiveness analysis framework that considers these real-world factors, facilitating the evaluation of alternative policies related to expanding or restricting first-line treatment choices. METHODS: We introduced a metric of incremental cost-effectiveness ratio (ICER) that compares an expanded choice set (CS) including the new first-line treatment with a restricted CS excluding the new treatment. ICER(CS) accounts for treatment selection influenced by heterogeneous treatment effects and policy implementation costs. We examined a basic scenario with 2 standard first-line treatment choices and a more realistic scenario involving diverse preferences toward multiple choices. To illustrate the framework, we conducted a retrospective evaluation of including versus excluding abiraterone acetate plus prednisone (AAP) (androgen deprivation therapy [ADT] + AAP) as a first-line treatment for metastatic hormone-sensitive prostate cancer. RESULTS: The traditional ICERs for ADT + AAP versus ADT alone and ADT+ docetaxel were $104 269 and $206 324/quality-adjusted life-year, respectively. The ICER(CS) for comparing an expanded CS with ADT + AAP with a restricted CS without ADT + AAP was $123 179/quality-adjusted life-year. CONCLUSIONS: The proposed framework provides decision makers with policy-relevant tools, enabling them to assess the cost-effectiveness of alternative policies of expanding versus restricting patients' and physicians' first-line treatment choices.

Modelling large scale artery haemodynamics from the heart to the eye in response to simulated microgravity.

We investigated variations in haemodynamics in response to simulated microgravity across a semi-subject-specific three-dimensional (3D) continuous arterial network connecting the heart to the eye using computational fluid dynamics (CFD) simulations. Using this model we simulated pulsatile blood flow in an upright Earth gravity case and a simulated microgravity case. Under simulated microgravity, regional time-averaged wall shear stress (TAWSS) increased and oscillatory shear index (OSI) decreased in upper body arteries, whilst the opposite was observed in the lower body. Between cases, uniform changes in TAWSS and OSI were found in the retina across diameters. This work demonstrates that 3D CFD simulations can be performed across continuously connected networks of small and large arteries. Simulated results exhibited similarities to low dimensional spaceflight simulations and measured data-specifically that blood flow and shear stress decrease towards the lower limbs and increase towards the cerebrovasculature and eyes in response to simulated microgravity, relative to an upright position in Earth gravity.

Studying the photothermal activation of polydopamine-shelled, phase-change emulsion droplets into microbubbles using small- and ultra-small-angle neutron scattering.

Polydopamine-shelled perfluorocarbon (PDA/PFC) emulsion droplets are promising candidates for medical imaging and drug delivery applications. This study investigates their phase transition into microbubbles under near-infrared (NIR) illumination in situ using small- and ultra-small-angle neutron scattering (SANS and USANS) and contrast variation techniques. Supported by optical microscopy, thermogravimetric analysis, and ultrasound imaging, SANS and USANS results reveal rapid phase transition rates upon NIR illumination, dependent on PFC content and droplet size distribution. Specifically, perfluoropentane droplets rapidly transform into bubbles upon NIR irradiation, whereas perfluorohexane droplets exhibit greater resistance to phase change (bulk boiling points = 30 °C and 60 °C, respectively). Furthermore, smaller emulsion droplets with unimodal distribution resist NIR-triggered phase changes better than their bimodal counterparts. This observation is attributable to the lower boiling points of large emulsion droplets (lower Laplace pressure than smaller droplets) and the faster photothermal heating rates due to their thicker polydopamine shells. The insights gained from these techniques are crucial for designing phase-change emulsions activated by NIR for photothermal therapies and controlled drug delivery.

Studying missingness in spinal cord injury data: challenges and impact of data imputation.

BACKGROUND: In the last decades, medical research fields studying rare conditions such as spinal cord injury (SCI) have made extensive efforts to collect large-scale data. However, most analysis methods rely on complete data. This is particularly troublesome when studying clinical data as they are prone to missingness. Often, researchers mitigate this problem by removing patients with missing data from the analyses. Less commonly, imputation methods to infer likely values are applied. OBJECTIVE: Our objective was to study how handling missing data influences the results reported, taking the example of SCI registries. We aimed to raise awareness on the effects of missing data and provide guidelines to be applied for future research projects, in SCI research and beyond. METHODS: Using the Sygen clinical trial data (n = 797), we analyzed the impact of the type of variable in which data is missing, the pattern according to which data is missing, and the imputation strategy (e.g. mean imputation, last observation carried forward, multiple imputation). RESULTS: Our simulations show that mean imputation may lead to results strongly deviating from the underlying expected results. For repeated measures missing at late stages (> = 6 months after injury in this simulation study), carrying the last observation forward seems the preferable option for the imputation. This simulation study could show that a one-size-fit-all imputation strategy falls short in SCI data sets. CONCLUSIONS: Data-tailored imputation strategies are required (e.g., characterisation of the missingness pattern, last observation carried forward for repeated measures evolving to a plateau over time). Therefore, systematically reporting the extent, kind and decisions made regarding missing data will be essential to improve the interpretation, transparency, and reproducibility of the research presented.