Surrogate Modeling of the Relative Entropy for Inverse Design Using Smolyak Sparse Grids.

Relative entropy minimization, a statistical-mechanics approach for finding potential energy functions that produce target structural ensembles, has proven to be a powerful strategy for the inverse design of nanoparticle self-assembly. For a given target structure, the gradient of the relative entropy with respect to the adjustable parameters of the potential energy function is computed by performing a simulation, and then these parameters are updated using iterative gradient-based optimization. Small parameter updates per iteration and many iterations can be required for numerical stability, but this incurs considerable computational expense because a new simulation must be performed to reevaluate the gradient at each iteration. Here, we investigate the use of surrogate modeling to decouple the process of minimizing the relative entropy from the computationally demanding process of determining its gradient. We approximate the relative-entropy gradient using Chebyshev polynomial interpolation on Smolyak sparse grids. Our approach potentially increases the robustness and computational efficiency of using the relative entropy for inverse design, primarily for physically informed potential energy functions that have a small number of adjustable parameters.

Structure Formation in Supraparticles Composed of Spherical and Elongated Particles.

We studied the evaporation-induced formation of supraparticles from dispersions of elongated colloidal particles using experiments and computer simulations. Aqueous droplets containing a dispersion of ellipsoidal and spherical polystyrene particles were dried on superamphiphobic surfaces at different humidity values that led to varying evaporation rates. Supraparticles made from only ellipsoidal particles showed short-range lateral ordering at the supraparticle surface and random orientations in the interior regardless of the evaporation rate. Particle-based simulations corroborated the experimental observations in the evaporation-limited regime and showed an increase in the local nematic ordering as the diffusion-limited regime was reached. A thin shell of ellipsoids was observed at the surface when supraparticles were made from binary mixtures of ellipsoids and spheres. Image analysis revealed that the supraparticle porosity increased with an increasing aspect ratio of the ellipsoids.

Ethics Education in U.S. Allopathic Medical Schools: A National Survey of Medical School Deans and Ethics Course Directors.

AbstractPurpose: to characterize ethics course content, structure, resources, pedagogic methods, and opinions among academic administrators and course directors at U.S. medical schools. METHOD: An online questionnaire addressed to academic deans and ethics course directors identified by medical school websites was emailed to 157 Association of American Medical Colleges member medical schools in two successive waves in early 2022. Descriptive statistics were utilized to summarize responses. RESULTS: Representatives from 61 (39%) schools responded. Thirty-two (52%) respondents were course directors; 26 (43%) were deans of academic affairs, medical education, or curriculum; and 3 with other roles also completed the survey (5%). All 61 schools reported some form of formal ethics education during the first year of medical school, with most (n = 54, 89%) reporting a formal mandatory introductory course during preclinical education. Schools primarily utilized lecture and small-group teaching methods. Knowledge-based examinations, attendance, and participation were most commonly used for assessment. A large majority regarded ethics as equally or more important than other foundational courses, but fewer (n = 37, 60%) provided faculty training for teaching ethics. CONCLUSIONS: Despite a response rate of 39 percent, the authors conclude that medical schools include ethics in their curricula in small-group and lecture formats with heterogeneity regarding content taught. Preclinical curricular redesigns must innovate and implement best practices for ensuring sound delivery of ethics content in future curricula. Additional large-scale research is necessary to determine said best practices.

Confined Dynamics in Spherical Polymer Brushes.

We investigate the dynamics of polymers grafted to spherical nanoparticles in solution using hybrid molecular dynamics simulations with a coarse-grained solvent modeled via the multiparticle collision dynamics algorithm. The mean-square displacements of monomers near the surface of the nanoparticle exhibit a plateau on intermediate time scales, indicating confined dynamics reminiscent of those reported in neutron spin-echo experiments. The confined dynamics vanish beyond a specific radial distance from the nanoparticle surface that depends on the polymer grafting density. We show that this dynamical confinement transition follows theoretical predictions for the critical distance associated with the structural transition from confined to semidilute brush regimes. These findings suggest the existence of a hitherto unreported dynamic length scale connected with theoretically predicted static fluctuations in spherical polymer brushes and provide new insights into recent experimental observations.

Propofol Induced Subacute Cutaneous Lupus Erythematosus: A Case Report.

We report a case of a woman who experienced unexplained recurrent rashes of varying severity after multiple exposures to anesthesia, and then 2 successful surgeries under general anesthesia with no resultant rashes after removing propofol from her anesthetic plans. We infer her previous postanesthetic rashes were likely associated with drug-induced subacute cutaneous lupus erythematosus (DI-SCLE) triggered by propofol.

Pushing the DIEP Envelope with ERAS: 24 Hour Discharge is Safe in Appropriately Selected Patients.

Enhanced recovery after surgery protocols have become increasingly adopted for autologous breast reconstruction, demonstrating improved quality of care and reduced hospital stays. Despite this, average length of stay remains over 3 days. We have found, in appropriately selected patients, hospital length of stay can be safely reduced to less than 48 hours. Methods: Retrospective review was performed of patients who underwent microsurgical breast reconstruction by the senior author (M.H.) from April 2019 to December 2021. Demographics, operative details, length of stay, and postoperative complications are reported to assess for safety of discharge within 48 hours, with the primary outcome measure being flap loss. Results: In total, 188 flaps were performed on 107 patients. Average age was 51.4 years (SD 10.1 years) with average BMI 26.6 kg/m2 (SD 4.8 kg/m2). Average length of stay was 1.97 days (SD 0.61 days), and 96 patients (89.7%) were discharged within 48 hours. Six flaps (3.2%) required operative takebacks. Five of the six (83.3%) takebacks occurred on postoperative days zero or one, and all five of these flaps were salvaged. There were four breast hematomas (2.1%), four breast seromas (2.1%), eight breast infections (4.3%), 13 breasts (6.9%) with wound dehiscence, four flaps (2.1%) with partial flap loss, and 24 breasts (12.8%) with mastectomy flap necrosis. One hundred fifty flaps (79.8%) had no complications. Overall success rate of flap reconstruction was 99.5%. Conclusion: Hospital discharge in 24-48 hours is safe in appropriately selected patients undergoing autologous tissue breast reconstruction.

Novel gas exposure system for the controlled exposure of plants to gaseous hydrogen fluoride.

Plants can serve as sensitive bioindicators of the presence of contaminant vapors in the atmosphere. This work describes a novel laboratory-based gas exposure system capable of calibrating plants as bioindicators for the detection and delineation of the atmospheric contaminant hydrogen fluoride (HF) as a preparatory step for monitoring release emissions. To evaluate changes in plant phenotype and stress-induced physiological effects attributed to HF alone, the gas exposure chamber must have additional controls to simulate otherwise optimal plant growth conditions including variables such as light intensity, photoperiod, temperature, and irrigation. The exposure system was designed to maintain constant growth conditions during a series of independent experiments that varied between optimal (control) and stressful (HF exposure) conditions. The system was also designed to ensure the safe handling and application of HF. An initial system calibration introduced HF gas into the exposure chamber and monitored HF concentrations by cavity ring-down spectroscopy for a 48-h period. Stable concentrations inside the exposure chamber were observed after approximately 15 h, and losses of HF to the system ranged from 88 to 91%. A model plant species (Festuca arundinacea) was then exposed to HF for 48 h. Visual phenotype stress-induced responses aligned with symptoms reported in the literature for fluoride exposure (tip dieback and discoloration along the dieback transition margin). Fluoride concentrations in exposed tissues compared to control tissues confirmed enhanced fluoride uptake due to HF exposure. The system described herein can be applied to other reactive atmospheric pollutants of interest in support of bioindicator research.

Role of Strong Localized vs Weak Distributed Interactions in Disordered Protein Phase Separation.

Interaction strength and localization are critical parameters controlling the single-chain and condensed-state properties of intrinsically disordered proteins (IDPs). Here, we decipher these relationships using coarse-grained heteropolymers comprised of hydrophobic (H) and polar (P) monomers as model IDPs. We systematically vary the fraction of P monomers XP and employ two distinct particle-based models that include either strong localized attractions between only H-H pairs (HP model) or weak distributed attractions between both H-H and H-P pairs (HP+ model). To compare different sequences and models, we first carefully tune the attraction strength for all sequences to match the single-chain radius of gyration. Interestingly, we find that this procedure produces similar conformational ensembles, nonbonded potential energies, and chain-level dynamics for single chains of almost all sequences in both models, with some deviations for the HP model at large XP. However, we observe a surprisingly rich phase behavior for the sequences in both models that deviates from the expectation that similarity at the single-chain level will translate to a similar phase-separation propensity. Coexistence between dilute and dense phases is only observed up to a model-dependent XP, despite the presence of favorable interchain interactions, which we quantify using the second virial coefficient. Instead, the limited number of attractive sites (H monomers) leads to the self-assembly of finite-sized clusters of different sizes depending on XP. Our findings strongly suggest that models with distributed interactions favor the formation of liquid-like condensates over a much larger range of sequence compositions compared to models with localized interactions.

A Scoping Review of Mobile Apps in Plastic Surgery: Patient Care, Trainee Education, and Professional Development.

Over the past 10 years, smartphones have become ubiquitous, and mobile apps serve a seemingly endless number of functions in our everyday lives. These functions have entered the realm of plastic surgery, impacting patient care, education, and delivery of services. This article reviews the current uses of plastic surgery mobile apps, app awareness within the plastic surgery community, and the ethical issues surrounding their use in patient care. Methods: A scoping review of electronically available literature within PubMed, Embase, and Scopus databases was conducted in two waves in November and May 2022. Publications discussing mobile application use in plastic surgery were screened for inclusion. Results: Of the 80 nonduplicate publications retrieved, 20 satisfied the inclusion criteria. Articles acquired from the references of these publications were reviewed and summarized when relevant. The average American Society of Plastic Surgeons evidence rating of the publications was 4.2. Applications could be categorized broadly into three categories: patient care and surgical applications, professional development and education, and marketing and practice development. Conclusions: Mobile apps related to plastic surgery have become an abundant resource for patients, attending surgeons, and trainees. Many help bridge gaps in patient care and surgeon-patient communication, and facilitate marketing and practice development. Others make educational content more accessible to trainees and performance assessment more efficient and equitable. The extent of their impact on patient decision-making and expectations has not been completely elucidated.

Closed-Loop tACS Delivered during Slow-Wave Sleep Reduces Retroactive Interference on a Paired-Associates Learning Task.

Previous studies have found a benefit of closed-loop transcranial alternating current stimulation (CL-tACS) matched to ongoing slow-wave oscillations (SWO) during sleep on memory consolidation for words in a paired associates task (PAT). Here, we examined the effects of CL-tACS in a retroactive interference PAT (ri-PAT) paradigm, where additional stimuli were presented to increase interference and reduce memory performance. Thirty-one participants were tested on a PAT before sleep, and CL-tACS was applied over the right and left DLPFC (F3 and F4) vs. mastoids for five cycles after detection of the onset of each discrete event of SWO during sleep. Participants were awoken the following morning, learned a new PAT list, and then were tested on the original list. There was a significant effect of stimulation condition (p = 0.04297; Cohen's d = 0.768), where verum stimulation resulted in reduced retroactive interference compared with sham and a significant interaction of encoding strength and stimulation condition (p = 0.03591). Planned simple effects testing within levels of encoding revealed a significant effect of stimulation only for low-encoders (p = 0.0066; Cohen's d = 1.075) but not high-encoders. We demonstrate here for the first time that CL-tACS during sleep can enhance the protective benefits on retroactive interference in participants who have lower encoding aptitude.

A 20-Year Analysis of Medicare Reimbursement for Abdominal Wall Reconstruction (2000 to 2020).

BACKGROUND: The purpose of this study was to evaluate monetary trends in Medicare reimbursement rates for 30 abdominal wall reconstruction surgical procedures over a 20-year period (2000 to 2020). METHODS: The Physician Fee Schedule Look-Up Tool from the Centers for Medicare and Medicaid Services was used for each of the 30 included current CPT codes, and reimbursement data were extracted. Monetary data were adjusted for inflation to 2020 U.S. dollars using changes to the United States consumer price index. The R 2 values for the average annual percentage change and the average total percentage change in reimbursement were calculated based on these adjusted trends for all included procedures. RESULTS: After adjusting for inflation, the average reimbursement for all procedures decreased by 17.1% from 2000 to 2020. The greatest mean decrease was observed for CPT code 49568 (the implantation of mesh or other prosthesis for open incisional or ventral hernia repair or mesh for closure of débridement for necrotizing soft-tissue infection, -34.4%). The only procedure with an increased adjusted reimbursement rate throughout the study period was CPT code 20680 (+3.9%). From 2000 to 2020, the adjusted reimbursement rate for all included procedures decreased by an average of 0.85% each year, with an average R 2 value of 0.78, indicating a stable decline throughout the study period. CONCLUSIONS: Reimbursement rates are declining when adjusted for inflation. Increased awareness of these trends is helpful to maintain access to optimal abdominal reconstruction care in the United States.

Operating in an Opioid Crisis: A Temporal Analysis of Pain Medication Prescribing Practices in Plastic Surgery.

BACKGROUND: In response to the opioid epidemic, the United States declared a public health emergency in 2017. We evaluated pain medication prescribing practices among plastic and reconstructive surgeons, assessing pain medication prescription rates and opioid-related mortality both nationally and regionally within the United States. METHODS: A retrospective analysis of Medicare Part D prescriber data among plastic surgeons from 2013 through 2017 was conducted. Pain medications were categorized as opioid and nonopioid medications. Trends in surgeon prescribing habits were evaluated using the Cochrane-Armitage trend test. RESULTS: A total of 708,817 pain medication claims were identified: 612,123 claims (86%) were for opioid pain medications and 96,694 claims (14%) were for nonopioid pain medications. Total pain medication claims decreased from 44% of all medications in 2013 to 37% in 2017 (P < 0.001). Opioid medications decreased from 37% of total medication claims to 32% (P < 0.001). The overall opioid prescription rate fell from 1.53 claims per beneficiary in 2013 to 1.32 in 2017 (P < 0.001). Nonopioid pain medications decreased from 7% in 2013 to 6% in 2017 (P < 0.001); nonsteroidal anti-inflammatory drug claims increased by 44%. The prescription rate of nonopioid medications decreased from 2.40 claims per beneficiary in 2013 to 2.32 in 2017 (P < 0.001). An overall increase in opioid-related mortality was observed. Trends in pain medication prescriptions varied significantly among US regions and divisions. CONCLUSIONS: Plastic surgeons are prescribing less opioids and relying more on nonopioid pain medications. Increased adoption of multimodal pain treatment approaches among surgeons is a likely explanation for this trend in face of the current opioid crisis.

Multiscale modeling of solute diffusion in triblock copolymer membranes.

We develop a multiscale simulation model for diffusion of solutes through porous triblock copolymer membranes. The approach combines two techniques: self-consistent field theory (SCFT) to predict the structure of the self-assembled, solvated membrane and on-lattice kinetic Monte Carlo (kMC) simulations to model diffusion of solutes. Solvation is simulated in SCFT by constraining the glassy membrane matrix while relaxing the brush-like membrane pore coating against the solvent. The kMC simulations capture the resulting solute spatial distribution and concentration-dependent local diffusivity in the polymer-coated pores; we parameterize the latter using particle-based simulations. We apply our approach to simulate solute diffusion through nonequilibrium morphologies of a model triblock copolymer, and we correlate diffusivity with structural descriptors of the morphologies. We also compare the model's predictions to alternative approaches based on simple lattice random walks and find our multiscale model to be more robust and systematic to parameterize. Our multiscale modeling approach is general and can be readily extended in the future to other chemistries, morphologies, and models for the local solute diffusivity and interactions with the membrane.

Trends in Medicare Reimbursement for the Top 20 Surgical Procedures in Craniofacial Trauma.

BACKGROUND: Research regarding financial trends in craniofacial trauma surgery is limited. Understanding these trends is important to the evolvement of suitable reimbursement models in craniofacial plastic surgery. The purpose of this study was to evaluate the trends in Medicare reimbursement rates for the top 20 most utilized surgical procedures for facial trauma. METHODS: The 20 most commonly utilized Current Procedural Terminology (CPT) codes for facial trauma repairs in 2018 were queried from The National Summary Data File from the Centers for Medicare & Medicaid Services (CMS). Reimbursement data for each procedure was then extracted from The Physician Fee Schedule Lookup Tool. Changes to the United States consumer price index (CPI) were used to adjust all gathered data for inflation to 2021 US dollars (USD). The average annual and the total percent change in reimbursement were calculated for the included procedures based on the adjusted trends from the years 2000 to 2021. RESULTS: From 2000 to 2021, the average reimbursement for all procedures decreased by 16.6% after adjusting for inflation. Closed treatment of temporomandibular joint dislocation and closed treatment of nasal bone fractures without manipulation demonstrated the greatest decrease in mean adjusted reimbursement at -48.7% and -48.3%, respectively, while closed treatment of nasal bone fractures without stabilization demonstrated the smallest mean decrease at -1.4% during the study period. Open treatment of nasal septal fractures with or without stabilization demonstrated the greatest increase in mean adjusted reimbursement at 18.9%, while closed treatment of nasal septal fractures with or without stabilization demonstrated the smallest increase at 1.2%. The average reimbursement for all closed procedures in the top 20 decreased by 19.3%, while that for all open procedures decreased by 15.5%. The adjusted reimbursement rate for all top 20 procedures decreased by an average of 0.8% each year. CONCLUSIONS: To the best of our knowledge, this is the first study to comprehensively evaluate trends in Medicare reimbursement for facial trauma surgical repairs. Adjusting for inflation, Medicare reimbursement for the top 20 most commonly utilized procedures has largely decreased from 2000 to 2021. Consideration of these trends by surgeons, hospital systems, and policymakers will be important to assure continued access to meaningful surgical facial trauma care in the United States.

Dynamic density functional theory for drying colloidal suspensions: Comparison of hard-sphere free-energy functionals.

Dynamic density functional theory (DDFT) is a promising approach for predicting the structural evolution of a drying suspension containing one or more types of colloidal particles. The assumed free-energy functional is a key component of DDFT that dictates the thermodynamics of the model and, in turn, the density flux due to a concentration gradient. In this work, we compare several commonly used free-energy functionals for drying hard-sphere suspensions, including local-density approximations based on the ideal-gas, virial, and Boublík-Mansoori-Carnahan-Starling-Leland (BMCSL) equations of state as well as a weighted-density approximation based on fundamental measure theory (FMT). To determine the accuracy of each functional, we model one- and two-component hard-sphere suspensions in a drying film with varied initial heights and compositions, and we compare the DDFT-predicted volume fraction profiles to particle-based Brownian dynamics (BD) simulations. FMT accurately predicts the structure of the one-component suspensions even at high concentrations and when significant density gradients develop, but the virial and BMCSL equations of state provide reasonable approximations for smaller concentrations at a reduced computational cost. In the two-component suspensions, FMT and BMCSL are similar to each other but modestly overpredict the extent of stratification by size compared to BD simulations. This work provides helpful guidance for selecting thermodynamic models for soft materials in nonequilibrium processes, such as solvent drying, solvent freezing, and sedimentation.

Theoretical and Experimental Considerations for Investigating Multicomponent Diffusion in Hydrated, Dense Polymer Membranes.

In many applications of hydrated, dense polymer membranes-including fuel cells, desalination, molecular separations, electrolyzers, and solar fuels devices-the membrane is challenged with aqueous streams that contain multiple solutes. The presence of multiple solutes presents a complex process because each solute can have different interactions with the polymer membrane and with other solutes, which collectively determine the transport behavior and separation performance that is observed. It is critical to understand the theoretical framework behind and experimental considerations for understanding how the presence of multiple solutes impacts diffusion, and thereby, the design of membranes. Here, we review models for multicomponent diffusion in the context of the solution-diffusion framework and the associated experiments for characterizing multicomponent transport using diffusion cells. Notably, multicomponent effects are typically not considered when discussing or investigating transport in dense, hydrated polymer membranes, however recent research has shown that these effects can be large and important for understanding the transport behavior.

Phase II testing of Xenon International on Mount Schauinsland, Germany.

Station RN33 on Mount Schauinsland near Freiburg, Germany, is part of the International Monitoring System monitoring radioxenon in air (131mXe, 133Xe, 133mXe, and 135Xe) for verification of the Comprehensive Nuclear Test Ban Treaty. Here, we present data from phase II testing of a new system, Xenon International at RN33, July 14th, 2021 to Jan 22nd, 2022, together with SPALAX data from the same time period. Radioxenon could be detected in 473 of 719 samples, among them many multiple isotope detections. Activity concentrations of spiked and selected environmental samples were verified by laboratory reanalysis. The sensitivity of Xenon International for radioxenons is up to one order of magnitude better for the metastable isotopes than that of the SPALAX, with a shorter sampling duration of 6 h.